Split (1)

train · 67.3k rows

text stringlengths 22 2.11M
[Question] [ Imagine a city full of people that are immortal; they can't die by aging and normal weapons can't hurt or kill them. So the government needs to find ways to overcome its overpopulation issues. After a protest of their previous attempts to handle the situation by execution, they were executed by weapons with special material that basically counters their immortality, by the government of the nation or city. What is a sensible way to handle this issue? [Answer] # Calling [2BR02B](https://en.wikipedia.org/wiki/2_B_R_0_2_B) > > "Thank you, sir," said the hostess. "Your city thanks you; your country thanks you; your planet thanks you. But the deepest thanks of all is from all of the future generations." > > > There are two measures of population control: The federal buraeu of Termination has set up an assisted suicide line, allowing every person to voluntarily end their life in a painless manner. They also track all other deaths, resulting in a quite well known number of population. But now let's assume people learned from the murder incident described in the short story. Instead of driving people mad and go to kill to make space, they prevent the tragedy in the first place. The federal bureau of Beginning is the administration considering birth licensesing. Without such a license it is impossible to get the needed fertility treatments to counteract the contraceptives that are administered with every and all food that can be bought. [Answer] Reduced Fertility These people are already half-like the Elves from bog standard Fantasy. Barring misadventure they are immortal. Here is a picture. [![enter image description here](https://i.stack.imgur.com/hWWHm.jpg)](https://i.stack.imgur.com/hWWHm.jpg) Fig A. Heavily Pregnant Elf. So why is Middle Earth not chock full of leaf-munching Elves who eat every last shred of vegetation until it becomes a barren desert? It is because they reproduce slowly. Their gestation lasts 22 months. Longer than man gestation, but in the grand scheme of a thousand year life not too bad right? Wrong. That's 22 Elf-months. Elf months are longer than man months. On top of that the Elves take hundreds of years to become sexually mature. They have low sex drive, and this is compounded by the hundreds of years of child-rearing it entails. The solution to your problem is to double down on the Elfiness. Instead of releasing a pathogen that makes everyone mortal, the government releases one that screws with people's ability to reproduce. Making them into slow reproducing Elves is one thing. But it is biologically implausible. And it is not reversible, which is a problem if there is a sudden war and we need to replenish the population. They could make a pathogen with an on/off switch. But that is even less plausible. Perhaps an easier solution is to make everyone sterile, so they can only have children through government-sanctioned Genetic Engineering Clinics. Then the government can control the population growth directly by not giving permission. Every time the city expands or makes a new colony, they issue a wave of birth licenses. Otherwise it a lottery for the one or two licenses each year to keep the population stable. [Answer] Spread out [![american colony](https://i.stack.imgur.com/jHiQE.jpg)](https://i.stack.imgur.com/jHiQE.jpg) <https://www.masslive.com/news/erry-2018/10/298f230f208827/these-are-the-51-oldest-towns.html> A time tested method to deal with surplus population is emigration. That works for many species. You have one city full of immortals. Clearly they need more space to house their numbers. Attached a map of Plymouth colony. You will see new towns were founded every generation. People live in between the towns too - a lot of them. These are farmers. The towns are sited to provide a central place for people who make a living in the country to congregate. If other cities are out there and not suffering the same issues, send people there. If there are not many cities, send your people out into the land as pioneers to found new cities. If the land outside your single city is so inhospitable your people cannot survive there, where is the food for this overpopulated city coming from? High tech? Or maybe they don't have to eat? [Answer] How about controlling the immortal population with some sort of birth control? I believe that there are many scientific methods of birth control, and in so far as your story might be a fantasy there could be magical methods of birth control. The lowest technology method of birth control is to capture all the immortals and transport the males and the females to different places where they will be guarded. Maybe they will be put on separate islands & the waters around the island will patroled. Immortals trying to sail away will be captured and tortured until they promise never to try to escape again. Or maybe two separate regions on land for the two genders could be surrounded by walls and guards. The immortal might be free to do whatever they want in their restricted areas so long as they don't try to escape, or they might be locked up in prison cells. IF guards come in routine contact with the immortals, presumably men would guard male immortals and women would guard female immortals, to avoid producing any half immortal offspring. I note that immortals don't have any need to reproduce to perpetuate the group. So persumably immortals would hav evolved or been created without any strong urges to reproduce. Thus they will find being unable to reproduce less stressful than most humans would. I also note that for thousands of years males were prevented from being able to reproduce by castration. So there are low tech ways to prevent immortals from reproducing, as well as more advanced medical or magical methods. [Answer] Some immortals just want to die. We can let them suicide with special weapons. Some immortals are assholes, making the life of other immortals harder. We can execute them. For example, in our society, many people support execution of rapists. I don't see why this is "inhumane". In most human socities, most people supported capital punishment for some crimes. Finally, we should severily restrict the birth rate. Just like in our society you need a license to drive an airplane, in this society you need a license to become a parent. [Answer] ## Set a maximum lifespan 1000 years is ages. Three days after your 1000th birthday, you get executed. For many, the last 20 years are spent contemplating death, leading to religious and/or philosophical awakenings. A few try hedonism or to complete bucket lists. Couples born within 50 years of one another that have been married for at least 200 years get to go out together at 1000 +/- x years, effectively transferring a few years allowance to the older partner. [Answer] ## Famine Your population may not die from aging or weapons but they will most probably die from hunger when the farms around the city are not enough to support the whole population. Probably this is what your government tries to solve in the first place, but the public will be much more helpful once dead, skeleton like bodies fill up the streets. If your people can not die from hunger as well, and do not feel hungry, congrats, you dont have an overpopulation problem. If they do feel hunger, but can’t die from it, follow the next solution. ## Purge Night Purge is a film series where the government allows killing for one night to combat overpopulation. Your society might be very elegant to organize one, but once hunger and lack of houses kicks in, they will participate. Hunger is a big gamechanger in human behaviour. So, your government just organizes a purge night,gives special weapons to the public and get out of the way. They don’t have to do the job themselves. Lack of quality of life will do it. And then there is one other option. ## Be invasive This is a bit different then just expanding. You should expand to places that are already occupied. Brainwash your public to go to war and create a never ending war, 1984 style, so that you can mobilise/conscript whenever necessary. You might suffer from success a couple times if your enemy uses conventional weapons, which expands your territory anyway, but at one point they will be equipped with the special weapons and the government will just be the victim of this never ending war. [Answer] Ask for volunteers to die. What can you do for your country? Many of them are probably bored out of their minds for living for so long. Some of them probably want to die already. If that's not enough, provide incentives. How? You can't pay them money; that's not something that they can take with them after they die. But maybe you can incentivize them with some pleasurable, one-of-a-kind experience that they've never had before. Maybe that experience is not normally available for any number of reasons. Even though people are immortal, that doesn't mean necessarily mean that they can't suffer permanent effects from a rare or illegal drug that could leave someone insane or debilitated1. Maybe it's so pleasurable and addictive that any immortals taking them would never want to stop, which would be so detrimental to society that the government needs to keep it tightly controlled, made available only as a "last meal". Heck, you don't even to create a logical explanation for what that one-of-a-kind experience is. Keep it a secret, and people will volunteer anyway, at which point the government can execute them with fewer complaints. 1 For that matter, being immortal doesn't necessarily mean that they can't become sick with incurable, chronic conditions and be in constant pain. [Answer] # They die on their own This race isn't immortal, just really hard to die. Because of this they have long come to the conclusion that they will die eventually and instead of trying avoiding it, they march to their deaths once they decide it is worth the risk. This race is full of glory seekers who would rather die doing what they love or fighting for what they believe in than by the many accidental deaths that could happen like drowning or starvation (everything is likely if you're going to repeat it forever), which in turn make them die earlier. # Strong body, weak heart Maybe mental health keep deteriorating with time, and I am not talking abou memory or sanity. Happiness is such a fragile and fleeting thing, one day you are the luckiest man in the world, the next day the love of your life elope with her secret lover and take your child with her, your best friend turn on you for reasons "you know very well" and on top of everything you hear a not very comforting comment about the whole affair from your neighbors. When life just keep going forever, is easy to get tired of it. Even if they don't straight up kill themselves over it, they may just stop bothering with life after a certain age, or even snap and go full psycho. And when it happens, the government can dispose of then in a humane way (literally putting then out of their misery). I think they have a similar justification for why vampires don't have friends in World of Darkness ttrpg, petty grudges keep adding up and become spite. # Enforced birth control Simply put, it is illegal to have a child without the government permission. Couples must apply to get the permission, until then and for those who don't want kids anyway, there are options ranging from normal contraceptives to induced infertility. In dnd, elves have a magical version of this. Instead of a government, there's a set amount of elven soul and the elf deity recycle the soul of the dead to use in the future new borns. If there's been happening too much births, its probably because something bad is going to happen (if they didn't need extra numbers, the deity wouldn't expend the emergency stock). That's also why they don't go extinct for lower fertility rate after tragedies, if there's extra souls lying around, the birth rate increase to compensate. [Answer] # Censorship. The curse of the immortals is that over a long enough time, no matter how they try, eventually each one must eventually speak some word so benighted that it cannot be pardoned, or perhaps even post a complete sentence that, if not caught by content filters at the time of utterance, will surely be understood to be intolerably profane or insensitive in a decade or a few centuries. When that time comes, these people must be excluded from the economic life of the city, never to be hired or welcomed to a public event. Without money, they must eventually lose all right to real estate. The police take them to the Pauper's Shelter, where they are hammered into a metal tube and dropped into a deep, deep borehole in the ground, never again to trouble civilized people with their inexpiable sin. Space above ground remains abundant. I would think very carefully indeed before you criticize this system, so essential for the orderly function of society. [Answer] > > What is a sensible way to handle this issue? > > > Culture. You are currently assuming that an immortal race will essentially have cultural norms, mores, and desires precisely equivalent to their mortal neighbors. If this immortality appears suddenly in a specific population (whether by a genetic mutation, a god's blessing/curse, etc.) then, okay, it is likely that those "first generation" immortals will be very similar to their mortal neighbors... But! It would only take a "generation" or two before culture is bound to diverge as more and more immortal children are born from immortal parents. Think of it this way: would any immortal mothers tell their immortal children "Don't play with that, you'll poke an eye out!" if mothers and the children themselves know that they are literally impervious to swords and arrows? (Presumably no; though gripes of "I just bought you that shirt, and it already has holes!" are likely to continue.) Similarly, ideas of "I'd better have a dozen kids so that at least one or two will survive to take care of me in my old age." will fade out quickly. Firstly, because the near-perfect survival rate makes that level of redundancy unnecessary; and secondly, but perhaps more importantly, because having immortality with no apparent age-of-enfeeblement completely eliminates the need for elder-care altogether. Your immortal city is likely to see birth rates plummet just as happens when countries nowadays become rich and developed. --- Lastly, how is "overpopulation" even defined for your immortals' city? The typical biological definition involves a population outpacing the carrying capacity of the location leading to die-offs. If natural "die-off" is completely impossible for your immortals, then the carrying capacity is effectively unlimited. In which case, "overpopulation" for your city is more of an artificial "NIMBY" problem than a technical one - and in which case economic and political power are likely what will determine what is acceptable and what "solutions" are possible. It seems odd that emigration isn't the simplest most obvious solution, though. [Answer] 1. Biological Immortality, not Magical Immortal Basically your species just doesn’t age once members hit their prime and/or are very difficult to kill, therefore they live forever . But, they can be killed, or be starved to death 2. Reduced fertility, Sex Separation, Sexuality First is simple: No matter how much they copulate,chances of impregnation are very low. Or, their culture is very sex positive and safe & protected sex is the norm Or, Most of the population is homosexual/ gay-leaning bisexual and heterosexuals are the queer and proud (You could also heterophobia as a flaw in society,”eww, breeders” or something). Or just make them asexual and machine-like logical beings ,similar to vulcans in Star Trek. 3. Go Big and Wide You have a setting where world is quite big compared to our earth, and flora & fauna is quite a lot more dangerous. In this setting, you could have them separated and scattered across planet in very small groups, and rampant danger makes it quite difficult to establish large settlements like cities. So, it’s just small villages in places hidden or guarded by natural barriers like mountains, hills and stuff. [Answer] # Vampire's solution: The mortal population of your world can decide to store the immortals in the smallest box they could find (likely a coffin shaped box), and make a stack of those. The immortal can't use energy, since energy transformation only go one way (from high quality to low quality, 2nd law of thermodynamic). This means that if they used/required feeding, they would die (thus, they won't be immortal). So, in the end, they can stay here forever. Without them being able to escape their box, they can't reproduce (again, energy here would be a problem, since you can't create matter out of nowhere), so the overpopulation problem soon becomes (only) a storage problem. Even if you have plenty of immortals in your world, it's always a lot less than the planet's available volume, so you should be able to store them in underground caverns, like we do for used radioactive material. That could be a punishment in law for immortals that are reproducing. [Answer] > > What is a sensible way to handle this issue? > > > The government decides to heavily promote a self-destructive culture by giving attention to bad things (mostrly caused by the government itself), also advertising all kind of unhealthy behaviour and stuff, and polluting food, water and air. After a while, the population internalizes the culture and keeps it up running without any help from the government. This is not going to kill them, but it will make them less fertile and also less willing to have a child in the first place. Also because most of them are reduced to be broke af so that they basically live only to work. The result being that the population will grow much slower. Slower enough that by the time overpopulation becomes a real threat, they are technologically capable of colonizing another planet. ]
[Question] [ There is an underground vault containing something very valuable. To prevent robbers from tunnelling to it, the security personnel regularly scans the ground with sound and geophysic sensors. Some robbers are aware of it, but they want to build a tunnel anyway. They have a lot of time, but only access to common building materials. Can they come up with some lining for the tunnel walls which will hide the tunnel? Just to make it clear, the mechanism to detect tunnels is the following. In a basement there is a heavy piston that at regular interval hits the ground to produce a booming noise. There is an array of fixed sensors that pick up not only reflected sounds, but also secondary transversal waves. [Answer] # No! Because hiding from ground sonar requires you to not reflect sound back AND not make a "shadow". This is not something common materials and tunnel construction can do. What is a shadow? Well, if you are used to seeing certain things in your sonar, and suddenly you stop receiving those signals because something is in the way, you are seeing the shadow of the thing. It is the lack of a signal or blocking a signal. Our robbers cannot simply stop the incoming sonar waves- they will cast a shadow if they only do that. Obviously, a shadow becomes especially concerning when it is slowly making its way to the thing you are trying to protect. Even if it isn't robbers, you likely wouldn't want whatever that is to collide with your vault. # But With More Science... They COULD achieve this; essentially, you bend the waves around the tunnel to make it seem like it is not there. It is called acoustic cloaking. (<https://en.wikipedia.org/wiki/Acoustic_metamaterial>) As far as I can tell, this has never been attempted but is possible. [Answer] # Dig deep and create a distraction You can avoid being spotted by ground penetrating radar and similar technologies by digging deep. The [Woodingdean Water Well](https://www.mybrightonandhove.org.uk/places/utilities/woodingdean-well/woodingdean-well) was dug by hand to a depth of 1,285 feet. Secondly, you can avoid detection from sound sensors by making a lot of noise elsewhere. In Better Call Saul, the bad guys cover the sound of underground blasting by having a large truck drive over a road plate at the exact moment of the explosion. If you team has more time and resources, they could come up with an even bigger source of noise. Maybe buy the land nearby and have a never-ending construction site? It would be hard to pick up the sound of tunneling when there's a [pile driver](https://youtu.be/H7mwqHn3G1Y?t=323) next door. Finally, you could try flooding your tunnel, possibly with a substance that's more viscous than water. That would lower the difference in density between the rock and the tunnel. Install a small airlock on either end. Either equip your robbers with SCUBA gear or use a robot. A robot would have the added advantage of requiring a very very small tunnel and it could support much higher density liquid without needing decompression (which wouldn't be practical here). Combined with depth and the noise and vibrations coming from next door, you'd have a shot at avoiding detection. (Edited to add last paragraph.) [Answer] If they were to drill small holes into the tunnel walls about 10ft deep, they could insert tiny microphones that would pick up the sonar (but are too small to set it off themselves). The microphones would connect to computers with a fiber optic cable. Light is faster than sound, so that you can actually see the sonar coming now a split second before it hits the tunnel walls. The computer then uses that split-second advantage to creating a dampening wave that makes it impossible for the sonar wave to bounce off the wall of the tunnel. It might also be necessary to send a false echo back up to several seconds later, it could do that as well. This only muffles the sonar ping, but wouldn't eliminate it completely. Which is probably ok... the stealth bomber doesn't have zero radar signature. It just looks so small that it doesn't appear to be aircraft at all. In the same way, sonar-stealthing the tunnel doesn't have to be perfect. Just has to minimize the signature so that it looks like some void or natural soil/rock boundary. [Answer] There are several tunnels. Each one is tiny. [![robot surgery](https://i.stack.imgur.com/mkhBZ.jpg)](https://i.stack.imgur.com/mkhBZ.jpg) <https://dilipraja.com/robotic-surgery/> Your robbers are going to use a surgery robot to do their heist. As opposed to traditional surgery where an opening is made big enough to visualize structures with the naked eye and grab them with a gloved hand, [robotic surgery](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1356187/) uses laparoscopic ports and robot-assisted manipulators. So too the robbers. Your robbers make several tiny tunnels to permit passage of the remote cameras and manipulators. They are detected but are so small they are considered to be animal burrows. The robbers never enter the vault. They enter remotely, via the robot. [Answer] An interface between solid ground and air will reflect back a good part of the sonar wave, because of the high mismatch in acoustic impedance. You can overcome the issue in different ways: * shape the tunnel in such a way that the sonar waves will be reflected away from the receiver. Basically mimic the early stealth technology * create a disturbing layer above your tunnel, so that it masks the underlying layer. The same way you can't see through a smoke curtain. You can do this by for example creating several air sacks above the tunnel. * you can try to tune the impedance of the tunnel wall so that the mismatch is lowered. The same way one uses a gel to remove air and better couple the echo-scan head to the body of the patient during a scan, you will basically make the tunnel less visible by reducing the reflected sonar wave. [Answer] # Build it under a rock shelf: First, let me say nothing is perfect. A sophisticated enough, determined enough foe will detect anything, because he will use multiple different techniques and carefully analyze minute differences over time. But a sloppily placed facility (like one placed historically and not with radar in mind) could be snuck up on. This requires that the local environment has soft soil over a hard rock shelf with soft materials under it. If the hard rock shelf can be tunneled under, then most [ground-penetrating radar](https://en.wikipedia.org/wiki/Ground-penetrating_radar) will travel through the soil and bounce off the hard rock surface. as long as the hard surface doesn't change appreciably (like people digging a shaft UP to a vault...) then the overall appearance of the underground won't change much. The electrical conductivity of the ground can change the ability of detectors, as can the type of soil and the amount of water in the soil. Perhaps building the tunnel under buried power lines might work, but I don't have a source on that. A tunnel dug through waterlogged materials (good luck!) will be very hard to detect (maybe a dig/pump/seal cycle?). Maybe dig the tunnel in wet materials, then drain the tunnel, dig, and reflood when the detectors are switched on? Or dig in SCUBA gear, if available. It would be a miserable process, but the tunnel might even look like natural erosion in a flooded space, and could be passed off as natural (I mean, who would use a flooded tunnel?) [Answer] There are two ways I see that could work, assuming that you need to build the tunnel right where the ground is scanned: Active cloaking Cancelling the tunnel's effect on active sonars is possible by using technology similar to that in today's noise cancelling headphones. The tunnel could in that way cloak itself by sending out "anti-sound" that cancels any reflection or shadow. I imagine one could record the incoming waves and use some kind of transform (similar to the [Fourier transform](https://en.wikipedia.org/wiki/Fourier_transform)) to figure out from which directions the waves come, and then send out the sound required to cancel any reflections and create new sonic waves in place of the shadowed waves. Even though this would technically be possible with today's technology and would not be mathematically that advanced, this would require acoustic sensors and actuators (i.e., microphones and speakers for recording sending out sound waves in the ground) all along and all around the tunnel. Passive acoustic coupling to make the tunnel transparent to sonic waves A couple of years ago, Steve Mould releases a [YouTube video](https://www.youtube.com/watch?v=AzZ7DjS4ti4) in which he explained why some interfaces reflect sound waves and why some interfaces don't reflect sound waves. He gave ultrasound gel as an example, which is used during ultrasound scans as an acoustic coupler to prevent sound waves from reflecting back once it hits the skin. Basically, a sonic wave will be (partially) reflected when it encounters an interface between two mediums with different [acoustic impedance](https://en.wikipedia.org/wiki/Acoustic_impedance). This is analogous to when a light wave hits an interface between two objects with different [refractive index](https://en.wikipedia.org/wiki/Refractive_index), such as the interface between air and water or between air and glass. A medium that transmits light and has the same refractive index as air will be invisible in air, and a medium that has the same refractive index as water will be invisible when submerged into water (note that the reason for example glass is not completely invisible is because it has a different refractive index than air and will therefore both bend light as well as reflect some of the light that hits it). The same goes for sonic waves—an interface between two medium with the same acoustic impedance will not reflect any sonic waves. Now, depending on how the tunnel is constructed, there may be several parts of a tunnel which all have different impedance. If the tunnel has some kinds of walls to prevent earth from falling in, those may have one impedance. The air inside of the tunnel have another impedance, probably much, much lower than that of the ground (for example, the human body has about 3,000 the impedance of air according to the video and it's probably not to dissimilar with the ground relative to air). All of those interfaces might reflect sonic waves. There are however several ways to tackle this. Perhaps a bit unintuitively, the sonic waves will be reflected less the more interfaces they have to pass, assuming that that allows the relative change in impedance across each interface to be lower. The ideal would be to have an impedance gradient between the ground and the air inside the tunnel, but several interfaces that helped transition the impedance in several small steps would probably be good enough. This would allow sonic waves to propagate into the air inside of the tunnel without being reflected. However, the sound waves would will still travel slower inside of the tunnel than outside of it, making them become out of [phase](https://en.wikipedia.org/wiki/Phase_(waves)) when they exit the tunnel again compared to the waves that passed next to the tunnel and never were slowed down, giving rise to [diffraction patterns](https://en.wikipedia.org/wiki/Diffraction) with constructive and destructive [interference](https://en.wikipedia.org/wiki/Wave_interference) which could give the tunnel away. Another strategy would be to add some kind of structure inside of the tunnel that could transmit the sonic waves straight through the tunnel with the same speed as waves in the ground outside of the tunnel, effectively making the sonic waves propagate through that structure instead of through the air inside the tunnel. For example, metal rods between the tunnel walls going in all possible directions could be added, or perhaps some sort of thredimensional metal grid. This would of course make it difficult to walk inside the tunnel, but perhaps it would be possible to create the structure in such a way that the waves propagated around the innermost part of the tunnel, freeing that for walking or crawling. This type of structure would of course make the tunnel take up a significantly larger volume, and it's not really clear to me exactly how you would design the structure to make the waves propagate with the correct speed in all directions, but maybe there is some clever way to design it that would make the tunnel as good as transparent to sonic waves. Clearly, this is a rather advanced concept (both mathematically and technically, I would guess). But maybe the team of robbers can pull it of if they know a mathematician who can come up with a theory that describes how a tunnel can be constructed that is coupled acoustically to the ground in an effective way, and an engineer who can help them build such a tunnel. [Answer] Fill the tunnel I'm not an expert enough to say the following will definitely work. Fill the tunnel with special material that acts for the scanners like the material that is being removed. Many kinds of insulation material comes to mind. That means with every scan the ground looks normal, as it is filled with a substitute soil. The substitute must be easy to temporarily remove or compress. That way you can quickly get by all of the substitute soil, giving access to where you'll dig. The digging area can't be lined according to the question anyway, so leaving a meter or so of working space at the end must not be too bad. It is likely small enough to not be a too big blip on the scanners to get suspicious, as no further tunnel goes to it. It would be easily dismissed as an error, if found at all. In short, you have a small digging area for advancement. The already created tunnel is filled with a substitute that looks alike to normal soil on the scanners. This can easily be compressed to the walls or removed and reapplied to allow diggers to and from the digging area, as well as removal of the dug soil. This will reduce the time the scanners can notice the tunnel. As scanning is done "regularly", you can time it well. If no one is digging, you can fill up the whole space. The above does have some logistical challenges with the passage to the digging site. If you make a good system to remove big blocks of material and reinstall them quickly, many cheap and abundant materials can do the trick. You might even just grab oblong blocks and turn them sideways, allowing you to walk past, closing the last one behind you and opening the next. [Answer] In addition to any of the tunneling methods in other answers, it sounds like you should also consider some other tools in thieves' arsenals while performing this heist. ### Social Engineering Are any of the guards or technicians involved at the vault being underpaid or treated poorly? Are any of them horny? Really gullible? Bribe, seduce, threaten, or trick them into helping you. * Get them to disable some of the sensors or the thumper machine itself to create an opening where you could tunnel undetected. * If the person manning the sonar sensor system can be turned fully to your side, they can simply never notify anyone else that a tunnel is being dug. * Get them to help with some of the suggestions in "Misdirection", below. The more benign what you ask them to do appears, the easier it is to get them to do it. If you find anyone willing to openly turn on their employers, you'll have to cut them in on a share of the loot, but you were already splitting the payout with the dig team anyway. ### Hacking Can you (or a socially-engineered insider) get physical access, even briefly, to the sensors or the computers? * Lock up the computers in the sonar sensor system with ransomware. That gives you a few days where no scanning is happening or the results aren't getting back to the humans. Perhaps long enough to dig your tunnel. As a bonus, if the vault's owners are dealing with a digital attack, they may be unlikely to expect a simultaneous physical breach. And if they pay off the ransom to regain control of their systems before your tunnel finishes, you still have a consolation prize. * Take over the computers and modify the data so the end users don't see any tunnel. This would get the same result as if you could perfectly disguise the tunnel against sonar. * Take over individual sensors, some of which are likely in less secure locations than the thumper or the computers. Have them to send back data masking your tunnel's presence. You might have to dig a winding tunnel to follow the sensors you control, but it'll still let you go undetected. Alternately or additionally, you could send fake data indicating an opening forming on the other side of the vault. ### Sabotage Can you damage or disable the scanning system? Can you do it in a way that will take time to repair and which appears to be benign in origin? * Cause a neighborhood-wide, multi-day power outage in the area the vault is situated. The vault may have a battery/generator backup. If it's batteries, they'll run out eventually. If it's a generator, try to put something in the fuel to break it when they try to refuel it. * Cause a major water leak near the vault. They'll have to dig up next to the vault to repair the broken pipe or fill in a sinkhole. Get in the work crew, or access the work area after dark. Then you can break into the vault without having to dig a tunnel at all. Or at the very least you could use the disruption in the sensor system as a cover for tunneling in on the other side. * Damage, e.g. by fire, the facility with the vault enough to trigger its contents being moved to another location while the facility is repaired. Cargo vehicles are often easier to rob than entrenched facilities. The faster they have to move to protect the vault's contents, the more chaotic it'll be and thus be easier to rob. Or maybe the temporary storage location is much less secure, making a heist there much easier than at the vault. Just make sure the damage doesn't actually reach whatever you're trying to steal. ### Misdirection Is the sonar system sophisticated enough to interpret a tunnel appearing and notify a human on its own, or does a human have to review and compare the results to come to the conclusion something is amiss? If the sensor system can't tell on its own that you're breaking in, you only need to keep the humans tending it busy somewhere else while your tunnel is being dug. Are there other avenues you could pursue at the same time which would draw their attention away, ideally for several days? * Infect other, more-accessible systems in the facility with ransomware. * Get the sensor system's handlers sick so someone less competent has to keep an eye on the scans. * Use government bureaucracy to force the owners to disable their thumper over concerns about how it's affecting wildlife or citizens living nearby. Whip up an angry mob of protestors outside the facility with rumors that the thumper is making them sick. Pseudoscience and wild accusations are your friend here. * Get the facility's manager promoted to a new site, ideally without a successor lined up. Or get them fired. * Trick the facility's manager into thinking they've been promoted and/or given a raise. When it doesn't materialize, they'll go on the warpath against their corporate overlords. You could use this technique on anyone you want to social engineer. Disgruntled employees are much more willing to take bribes or sabotage critical systems. * Start (or take advantage of) some noisy construction next to the facility. Get the construction crew to "accidentally" damage something at the facility - could be a wall, a power- or water line, whatever; it has to be enough to disrupt the facility for a few days. If you can't get the crew to do it for you, just use one of your team in disguise. * Hire a second, incompetent team to attempt their own heist. When they inevitably get caught, you cut contact and hang them out to dry. (And if by some miracle they succeed, then being their employer you have also succeeded. Pay them fairly and do not double-cross them.) [Answer] # Yes, if you know a) the origin of the signal and b) the wavelength of the signal. It is entirely possible to construct an arrangement of reflectors such that it does not reflect a wave signal back to its source for some set of directions (geometric stealth) nor does it obscure a signal of a given wavelength (geometric transparency). A tunnel, being acoustically a boundary between two materials of very different acoustic impedance values (air vs rock), is effectively a reflector (it also refracts some amount of sound through it--the walls transmit sound to the air, which retransmits to the other side, and sound can also travel along the boundary--but this can all be mitigated by appropriate acoustic insulation). Thus, if an appropriately complex tunnel is dug, it is possible to obtain a reflector with both geometric stealth and geometric transparency, provided you know the direction the signal is coming from and what wavelength it is. Making a reflector be geometrically stealthy is trivial--just don't have any surfaces reflecting the signal back to the detector. Making a reflector be geometrically transparent can be much more difficult. Why? If the reflector is much smaller than the signal wavelength, it will not obscure the wave--the wave will go right through/around it with minimal energy loss--there is no "shadow". This is why small metal objects don't block radio waves. If the reflector is much larger than the signal wavelength, it will cast a shadow. This is why light is blocked by small metal objects. If the reflector is about the same size as the signal wavelength, it will refract about it in interesting ways. If you have a large tunnel which casts an acoustic shadow, many smaller tunnels near the size of the signal wavelength may possibly curve the acoustic signal around the wave in such a way that its presence is indistinguishable from its absence, after a certain distance. [Here is an example (note that it is a VERY reflective structure, however)](https://www.youtube.com/watch?v=Z8d3N2_nvBc). This is why you often hear the term 'metamaterials' thrown around in regards to invisibility--if a material is made to be transparent to visible light despite being very large, it must have extremely fine structure on the wavelength of the light to bend it around itself. Of course, this is all probably a moot point because the wavelength of geophysical acoustic methods is much larger than human-sized tunnels & so it won't be noticed as long as it is not reflective. GPR may be a problem however, as its wavelength is much finer. Still, casting an acoustic shadow doesn't matter if you don't have buried receivers below you--nobody cares if there's a shadow if there's nobody to see it; and surface receivers will only detect reflections back at them. Which brings me to my next point... The biggest issue is that if you have multiple receivers, it doesn't matter how geometrically transparent you are if you aren't geometrically stealthy. While it is easy enough to defeat a single emitter/detector system (provided there's not a lot of other reflectors nearby that may eventually kick your signal back at them, if there are many detectors, or worse, many emitter and many detectors, it is impossible if not difficult to avoid returns to all of them unless you have perfect data... and even then it's still very unlikely. This is why modern stealth aircraft aren't as angular as early ones, and rely more on absorption of the signal than minimizing reflection back to a single detector. Still, in theory it is possible. Whether it is practicable depends on the details. [Answer] No ... unless the vault was built before people got concerned about tunneling (might be if the 'vault' was built without an eye for security, and the location and facilities could not be upgraded later, for reasons, when it became apparent how valuable the contents were) * If it is built into solid bedrock, trivial passive listening will be sufficient - the process of removing stone in any quantity will produce sound, which can be picked up and even localized using triangulation. Plot any picked-up noise on a 3D chart, and watch as the tunnel extends towards you. * If the land around it is owned and controlled by the people operating the vault, the passive surveillance can be even better, so even if the vault is sitting in gravel, or sand or silt, the scratching noises could be picked up, triangulated and plotted. * even if there are caves with fast-flowing-gravel-carrying water, a subway, a glacier, and nuclear shelters remodeled as techno-clubs nearby, you just need more and better microfones in your array to weed out the different sound sources. If this is a vault that was installed before, and for secrecy reasons you absolutely cannot [install microfones](https://www.researchgate.net/publication/7206787_Geophone_Detection_of_Subterranean_Termite_and_Ant_Activity) around it now, indeed you only can send clandestine teams of security with the sensing gear disuised as a zamboni - then yes. Underground sensing from single points of vantage for static stuff (instead of the microfone-case, where the killer-info is in the development of the distribution of the data) is very hard, getting exponentially less resolution the deeper you go - See any ['geophys'-heavy episode of TimeTeam](https://www.youtube.com/watch?v=1hVexForDh4) (and note that they are looking for, and overlooking, stuff that is only a few feet underground). [Ground penetrating radar](https://en.wikipedia.org/wiki/Ground-penetrating_radar) will only get you a few meters depth, and the resolution of acitvely sounding the earth is [not sufficient](https://earthscience.stackexchange.com/questions/7786/can-ultrasounds-be-used-to-map-the-density-of-large-underground-regions) to reliably detect a small tunnel. [Answer] [Detecting tunnels using seismic waves not as simple as it sounds](https://phys.org/news/2012-12-tunnels-seismic-simple.html) That's literally what references say. Detecting a tunnel with seismic waves is far from guaranteed, and if it's small and relatively deep, it can get undetected. In fact, to detect small irregularities in soil, like shallow pipes or sewers, [ground-penetrating radar](https://en.wikipedia.org/wiki/Ground-penetrating_radar) is more useful than seismic waves, and that is far from perfect and has a very limited range. Therefore, the answer is to go deep, to make the tunnel small, not to change the environment so much, and not to get scared by seismic detectors because they aren't great at detecting tunnels. [Answer] By pretending to have another acoustic obsticle in front of the tunnel, you could do it, with sound absorbing materials in layers, make it look like a huge natural fault line, cavern or oil deposit. That could be done with named above sound absorbing materials -and/or active microphones and some really low bass speakers. Basically noise chancelling headphones but for seismographic waves. Of course economically that whole affair is not viable. So just frack it and inject a sound absorbing material? [Answer] # Build many nearby tunnels for legitimate reasons. as you increase the number of tunnels, scanners become less and less useful. For example, have the thieves build a legitimate goldmine next door ## Pick a legitimate reason for needing to dig neighboring tunnels, such as * mining for salt, gold, ore, rocks, etc.. * archeology finds (maybe they found ancient ruins nearby and want to discover what the ancient civilization left behind, or at least they pretend to) * burying cable lines * building an Underground Railroad * laying water pipes very low * tunnels for geothermal energy * tunnels just for fun * car tunnels to speed up traffic * pick a reason that's legitimate for them to need to dig tunnels, and make sure there's a labyrinth of tunnels already in place that are already close enough to the vault, so when the theft-day arrives, all they have to do is connect the vault to their already existing network of legitimate tunnels that was nearby. This question was edited from originally saying: "Dig millions of tunnels." ]
[Question] [ I'm attempting to design a desert area that could almost constantly be covered in a thin layer of smoke. It does not block out the sun but instead sticks closer to the ground. The land is hot, arid, and sandy. It has some grassy vegetation, and I am open to having it be volcanic. The actual land itself is reminiscent of the Sonoran or Tanami Desert, or perhaps even the Atacama Desert, but with darker sand and a great amount of smoke covering the surface. What might be a reasonable explanation for this phenomenon? So, to summarize, I would like for the phenomena not interfere with: -the dark, blackened coloration of the sand -the grassy areas scattered around the desert -the somewhat flat, rocky terrain. [Answer] Something underground is burning. [![centralia mine fire with skeleton](https://i.stack.imgur.com/NHTqF.jpg)](https://i.stack.imgur.com/NHTqF.jpg) <https://www.centraliapa.org/about-centralia-pa-mine-fire/> The bones are kind of extra but this is a good photo of the Centralia mine fire. There is a large coal mine underground and it is on fire. It is choked for oxygen but gets enough to keep on and it is so extensive that efforts to extinguish it have failed. I used to think it was smoke coming out of the ground at these coal fires, but in this photo it is labeled steam and I bet that is right. Combustion makes a lot of water and hot vapor would be more visible than smoke. Under the right conditions there is no doubt smoke too. --- Burning tar sands. [![tar sands](https://i.stack.imgur.com/MllKD.jpg)](https://i.stack.imgur.com/MllKD.jpg) <https://www.youtube.com/watch?v=_qKfVwAmKpw> Your sands are black because of natural tar seeps in the area. With the tar comes lighter molecular weight material including more volatile hydrocarbons and gas. This stuff oxidizes in the hot sun, making the sands hotter than they would otherwise be just from sunlight. Sometimes it gets hot enough to ignite. The tar and asphalt does not burn completely and makes heavy hazy smoke that drifts over the landscape. [Answer] You might be looking at a series of [fumaroles](https://en.wikipedia.org/wiki/Fumarole). These are steam-producing features created by interaction between groundwater and volcanic heat. They are rather flexible: they can appear a few at a time or by the thousands, they can last for only a few years or virtually indefinitely, depending on the nature of the heat source. Because they often give off noxious gasses (sulfides especially) the area immediately around fumaroles tends to be barren, but they could be dispersed enough to allow for patches of plant life in between vents. [Answer] It's a series of ventilation shafts for dwarves who smoke during their breaks from mining and smelting. Occasionally an unbroken smoke ring will escape with a tantalising whiff of Longbottom Leaf or Old Toby. Also of course the smelting of metal produces a lot of smoke of its own account. [Answer] Simple: Have an underground coal deposit, and let it burn. That will create smoke for decades to come, especially if said coal deposit is large enough. ]
[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/143172/edit). Closed 4 years ago. [Improve this question](/posts/143172/edit) We know the common tropes for an apocalyptic event: meteor/asteroid hits earth; crazy infectious virus/bacteria; AI takes over; we nuke ourselves; climate change; hostile aliens. But what are some other, less known but still plausible, ways an apocalyptic event could go down. Requirements: * Human populations must experience a devastating blow (say at least 75% dead, and does not need to be evenly spread out) or be completely eliminated * The blow to humans can be direct (e.g. radiation poisoning) or indirect (e.g. starvation because no arable land) * All other plants and animals may or may not be affected (this is unimportant) * This has to be somewhat plausible according to today's science (e.g. no time-traveling humans from the future, no we all get sucked into a parallel universe) * This can't be a super popular or well known apocalyptic premise (e.g. no hostile AI takeover) I'm looking for things like: [Phytophthora](https://en.wikipedia.org/wiki/Phytophthora), a water-mold genus that affects a wide range of food crops (think potato famine) mutates and destroys crops worldwide. Or a rogue planet enters the solar system and takes earth out of orbit. Or the whole gamma-ray burst thing. Or a super-volcano goes off. Basically anything that is somewhat scientifically plausible but not (very) common knowledge. Please also give evidence as to why this event could be feasible (though I would also be interested in well theorized events without as much evidence) EDIT: to prevent this from being viewed as a subjective question, here are my objectives for accepting an answer: I will accept the answer with the most plausible theory (ideally with references or past examples), while still being relatively unknown (see the first paragraph of my question for 'commonly-known' apocalyptic events). I understand many apocalyptic possibilities have an unknown likelihood (e.g. the Fermi paradox illustrates how we have no clue how likely aliens are to exist) but some (e.g climate change) are currently more likely than others (e.g. hostile aliens - given we don't have any indication of aliens visiting earth in the millions of years its been here) and we can predict the likelihood of many events (e.g. how often super-volcanoes go off, how many are on earth, when they last erupted etc.). I also don't want answers that have lots of steps that each have their own likelihoods (e.g. the plot of the movie Life: life found on Mars (some degree of unlikely), it grows and becomes/is sentient (unlikely), it becomes harmful/malevolent (unlikely) it escapes to earth (again another step) where it can rapidly spread throughout the ocean (another step) and kill everyone.) EDIT 2: PS even if it makes the mods grumpy I do like it when people come up with crazy/'bit of a stretch' answers (who knows maybe they will help someone who is reading this with their own world-building), I will upvote them if they are still (somewhat) scientifically plausible and not commonly known. [Answer] Artificially generated Peak Oil event. One of the trickiest technological approaches to problem solving, and the one that has consistently generated the bulk of our unanticipated consequences, has been the introduction of biological controls into the ecosystem. That said, we continue to develop such controls because they tend to be quite effective, at least in the short term. So; enter [Alcanivorax borkumensis](https://www.sciencedaily.com/releases/2018/04/180409144725.htm), a bacteria that literally eats oil and has been designed to help with environmental contamination scenarios when oil tankers & rigs spill massive amounts of oil into the ecosystem. We are now working on a transition away from fossil fuels globally but setting up new infrastructure, bringing costs of new technology down etc. takes time and the world isn't ready for an instant peak oil event. But, if this bacterium got out into the ecosystem in an uncontrolled manner and infected all the oil reserves globally at the same time, we could end up with oil depletions on a massive scale within months. Believe it or not, this would be every bit as devastating as a human infection. For a start, your 75% death rate would be achieved relatively quickly by virtue of the lack of food getting into large cities. Oil (read as petrol) is now a critical part of the food chain because of the food distribution requirements of larger population centres. Large cities simply don't produce much food, but they consume massive amounts of it. Disrupt fuel supplies for a month, and you'll face a complete and total breakdown of law and order and city life, triggering massive unrest, deaths from starvation and civil disobedience, and a mass exodus from the cities into country locatinos without the infrastructure to support the survivors. Not to mention that most farms today are 'productive' thanks to fuel and technology that is no longer available. Also, many modern farms contain genetically modified seed stocks that can't be replenished through 'seed cropping' and the fertiliser needs of the soil are massive, meaning that without a functioning distribution network the farms simply couldn't support the populations coming out of the cities even if they wanted to - farming looks too different from 100 years ago when all those people could have been put to work on the farms instead of machines. This is not a total extinction event by any means, and certainly pockets of civilisation would survive because of the use of nuclear and renewable electrical grids and the uptake in certain areas of electric vehicles, but planes would be grounded, we don't really have a functioning electric heavy vehicle infrastructure in place and many societies still rely on petrol as a key driver of their infrastructure. As such, you'll find that your society would face massive losses in the short term, and significant losses over the medium term, if all the oil on earth just suddenly vanished. [Answer] Here are a few: 1. Super massive solar flare removes most of our atmosphere/scorches the earth. Hard to balance between everything destroyed and nothing destroyed, the earths magnetic field stops most solar wind from doing damage, but it could be overwhelmed. 2. Cult like religion takes over with a goal of depopulation. No explanation needed. 3. Collapse of an overly centralized system. Say technology advances to the point of completely replacing human labour. To counteract the massive loss of jobs, the government takes control of production. If the government was then to collapse, the supply of everything could disappear. Even if the production mechanism is fixed, the complete disappearance of the food supply for example would do massive damage in just a week (though a couple months would be where the real collapse would probably peak). 4. Widespread use of a flawed genetic procedure. Say a gene editing program begins to give everyone a gene that prevents cancer. It turns out the gene is flawed and stops the ability to reproduce after a number of generations. It is likely that technology would also then be able to remove the gene, but this can be an odd one. [Answer] In the webcomic Nine Planets Without Intelligent Life, humanity just felt in such an hedonic state that people stopped reproducing. They would have robots serving and pleasing them in all ways possible and lost interest in human reproduction. Eventually humans all died out. This is tangentially aligned with the [V.H.E.M.T.](https://en.wikipedia.org/wiki/Voluntary_Human_Extinction_Movement), which is a thing in the real world: > > The Voluntary Human Extinction Movement (VHEMT) is an environmental movement that calls for all people to abstain from reproduction to cause the gradual voluntary extinction of humankind. > > > [Answer] A [near-earth supernova](https://en.wikipedia.org/wiki/Near-Earth_supernova) could do the trick, as could a [neutron star flare](https://www.symmetrymagazine.org/article/five-extreme-facts-about-neutron-stars). Mass sterility induced as a side-effect of a commonly used drug or energy drink. Something like this is in fact [already happening](https://www.theguardian.com/science/2017/jul/29/infertility-crisis-sperm-counts-halved). Most people choose virtual reality over real life and neglect procreation until too late. People used to physically perfect (and willing) virtual partners may be disgusted by real-life sex partners or decide that it isn't worth the hassle. This is [already happening in Japan](https://www.asiaone.com/asia/japanese-men-marry-anime-characters-vr-wedding). The successor to the Large Hadron Collider; the [Future Circular Reactor](https://hackaday.com/2019/02/07/the-future-circular-collider-can-it-unlock-mysteries-of-the-universe/), may accidentally produce a black hole that absorbs the earth or even cause some totally unforeseen event, like creating a short-lived wormhole that sucks in most of Europe and causes massive earthquakes and tsunamis on the rest of the planet. [Answer] ## Earth impact events Most people think of catastrophic asteroid impacts to be extremely rare events, or don't even consider them plausible. A category 9 or 10 impact on the [Torino scale](https://cneos.jpl.nasa.gov/sentry/torino_scale.html) would cause extreme damage: > > 9: A collision is certain, capable of causing unprecedented regional devastation for a land impact or the threat of a major tsunami for an ocean impact. Such events occur on average between once per 10,000 years and once per 100,000 years. > > > 10: A collision is certain, capable of causing global climatic catastrophe that may threaten the future of civilization as we know it, whether impacting land or ocean. Such events occur on average once per 100,000 years, or less often. > > > ![Torino scale](https://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Torino_scale.svg/1024px-Torino_scale.svg.png) ## Quantum tunneling Just for fun, let's take out the "relatively unlikely" clause from your requirements... [Quantum tunneling](https://en.wikipedia.org/wiki/Quantum_tunnelling) (a real-life version of wall glitching in video games) can, in theory, cause all of Earth to spontaneously collapse in on itself and become a black hole, but the chances that it would occur before every last star in the universe has become a black dwarf is likely smaller than the chance of you winning every lottery in the world for the rest of your life, and not being accused of cheating. This event is physically possible because subatomic particles do not exist in any one, discrete point. They are actually probability functions and exist everywhere with a specific probability. This allows one subatomic particle to pass through a barrier that it otherwise could not pass through, such as another subatomic particle. If enough particles on Earth happened to pass through each other and end up at the same place, the mass would be sufficient to cause an immediate collapse into a singularity. This is actually something that we expect to happen in the future, at least if protons do not decay first. Between around $10^{10^{26}}$ to $10^{10^{76}}$ years in the future, all objects larger than the Planck mass will see this fate. From a Wikipedia article on a [timeline of the far future](https://en.wikipedia.org/wiki/Timeline_of_the_far_future), this is: > > [...] the time until all objects exceeding the Planck mass collapse via quantum tunnelling into black holes, assuming no proton decay or virtual black holes. On this vast timescale, even ultra-stable iron stars are destroyed by quantum tunnelling events. > > > An additional note is given regarding the estimates of the timespan: > > Although listed in years for convenience, the numbers beyond this point are so vast that their digits would remain unchanged regardless of which conventional units they were listed in, be they nanoseconds or star lifespans. > > > [Answer] A False Vacuum Collapse The quantum vacuum is a measure of the lowest possible quantum energy state. Some scientists have hypothesized that if our current quantum vacuum was not the actual lowest energy state, but simply a metastable local minimum (a false vacuum), then it would theoretically be possible for the universe to transition into the actual lowest energy state, which would release a very large amount of energy from basically everything. A false vacuum collapse, could if it occurred, destroy all of the observable universe, starting from a single point and expanding in a bubble that expands at the speed of light. Since it expands at the speed of light, we would have no idea that the wavefront was approaching us until it reached us. Once that occured, humanity, the Earth, and the Solar System in general would all cease to exist as space-time exploded in a massive release of energy. [Answer] I'm surprised no one brought up [super volcanoes](https://en.wikipedia.org/wiki/Supervolcano)... One of them blowing would bring upon the world volcanic winter (and a dinosaur-like extinction event) The eruption itself might or might not be preceded by earthquakes and deformations of the landscape surrounding the super volcano itself, announcing the imminent explosion. Once the blast occurs, the first damage would be to the surrounding area by means of [blast-wave](https://en.wikipedia.org/wiki/Blast_wave), [hot ash](https://en.wikipedia.org/wiki/Pompeii) and thrown debris from inside the volcano. The blast itself will throw [HUGE amounts](https://en.wikipedia.org/wiki/List_of_largest_volcanic_eruptions#Explosive_eruptions) of ash and very small particulates into the atmosphere, preventing the sun's heat and light from reaching the ground. This would, in turn, [cause a rapid drop in temperature (volcanic winter)](https://en.wikipedia.org/wiki/Volcanic_winter), and would cause crops to fail and livestock to die due to decreased temperatures and lack of sunlight. There is a very interesting paper written in 2014 which has tried modelling the Yellowstone Supervolcano eruption fallout. It details the ash distribution (over US) taking into account the wind patterns. You can find it [here](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GC005469). (I am not connected to that study in any way) Edited for a more complete answer [Answer] # Information Collapse Human Society is dependent on data. While it seems trivial to run the entire world "by hand", it's not possible on the scale humanity has found itself. Imagine, if you will, a malware that would infect every remotely sophisticated information processing machine. Servers, Personal Computers, Laptops, Smartphones, Embedded Devices, Calculators, etc. All of them would cease to function. Society as we knew it would collapse. We wouldn't be able to manage traffic, bring goods from A to B or instantly communicate over long distances. This may seem benign at first, but let's have a look at things. ## Timeline of events ### At the collapse People would notice that their phones and computers would stop working. Some would angrily shout at their headset why they got disconnected from Counter Strike when they only needed to win one more round to win the match. Others would try to smack their remote because the TV wouldn't turn on. Many would then try to gather information about why nothing is working, but they can't "google the problem" because Google itself is no more. ### Shortly after the collapse People gather outside, trying to figure out what's going on. Power has gone out, because the control software for the power plants has gone out. Some are quick to realize something is amiss and try to gather as much food as possible. Supermarkets can't make bills for the customers, so they just take food by force. What are they going to do? Make smoke signs to call for the police? ### Several days after the collapse People with older cars might have a chance to get them running, at least until the gas is out, but most people will favor bicycles or similar modes of transportation. Communication between people is now mostly verbal or with notes left behind. People try to find their loved ones to make sure those are okay. Food supplies are still fine, but decreasing. Fresh water has been identified as a valuable commodity. ### Several weeks after the collapse Many people have died of dehydration, others of the violence that has resulted from the lawlessness. Communication has become difficult, especially for authorities to coordinate each other. Remote areas either died out because of the lack of supplies, or managed to sustain themselves due to access to water and food. ### Several months after the collapse Technology has somewhat revamped to pre-WWI era. Many people have died due to the lack of supplies and coordination among people, but far more due to mass hysteria among people. Military forces either aided the government in keeping the leadership, or took the opportunity to become leadership. ### Several years after the collapse Humanity has stabilized again. Some areas recovered back into civilizations, while others are better described as barbaric and lead by whoever has the most force. The collapse mostly affected the developed world, especially overcrowded cities such as New York, Tokyo, Hongkong, Paris or Berlin. [Answer] All very good answers. I will, however, tackle the problem with oblique approach: 1. Aforementioned Solar flare - it doesn't have to be big. All it needs to kill in excess of 75% of the population is to coincide with magnetic field reversal. There are, actually, some achaeological finds that suggest something like this happened on Earth already. In fact, some suggest just magnetic pole reversal can do it - predicted result would be dramatic increase in harmful solar radiation that's reaching Earth's surface in many places, increasing temperatures and killing with prolonged exposure. 2. Collapse of electric grid world wide (for any of the various reasons) - most of the urban population does not stock food, average household has less than a week's worth. Stores do not have more, too - at most 3-4 day supply. Once electricity is out, logistics and refrigeration is out, causing civil unrest. It is estimated that without power for more than a two weeks (maybe even one), in about 6 months Developed countries' population would drop by at least 75%. But obviously it would not impact undeveloped areas of the world that much. Africa and similar would probably see 50% drop. 3. Supervolcano or several large volcanic explosions in a year, at the right time of year - they would increase occlusion of the atmosphere, reducing available sunlight and reducing global temperatures, which in turn will impact crop yields. Not sure how big taking into account current high CO2 content (it is a plant nutrient, so the more the better for them), but just 10% reduction means famine, which means social collapse worldwide. and then see No 2. [Answer] A celestial body passes through the inner Solar System Anything ranging from a planet to a black hole moves close enough to perturbate orbits of planets or asteroids. Possible outcomes are: * Impact event. * Tidal forces shatter the Earth's crust, severity varies from earthquakes to seas of magma. * The Earth's orbit changed or it is ejected from the Solar System. It becomes really hot or cold in several months after the event. * Orbits of the Earth and some asteroids from the belt now intersect. Delay of the impact may be anything from months to thousands of years. * Another inner planet shattered with its pieces gone astray. [Answer] Well, this has been partly mentioned in one form or another, but a powerful solar storm could trigger a mass extinction of humanity (and only us). I haven't seen it in any apocalyptic movie or book yet, but something like this happened before : <https://en.wikipedia.org/wiki/Solar_storm_of_1859> TLDR: a powerful coronal mass ejection from the sun hit the Earth. It was seen as auroras all accross the continents and created one of the strongest geomagnetic storms on record, causing telegraphs (the only electrical systems at the time) to fail. If it happened nowadays, replace telegraphs with most of our electrical grid and electronic devices (that means no cars, trains, planes or boats too). From there, the minimum we can have would be mass deaths as cities stop getting supplied in food and water and possibly the complete breakdown of society, replaced with an 'everyone for themselves' scenario. Humanity won't go extinct, no risk of that and wildlife will be unaffected. [Answer] Some other fun ones: If we humans really are a simulation, some higher power entity might get bored and input something ridiculous onto our planet, like a new life-form, to kill us all off. Somehow, a deadly poison gets into the oceans, killing a lot of people who drink/come into contact with it. On Earth, some government-type people decide that cannibalism would be the best solution to both world hunger and overpopulation. Enough said. Self fulfilling prophecy: The scientists lie to the people, convincing them that an unrelated extinction event really is happening, leading to massive "drink-the-kool-aid-style" suicide events. A new kind of addiction ravages the world, decimating society at large. An advanced society decides to kill off us pesky humans to take over our planet. Instead of actual warfare, they just put a spaceship into orbit around the sun, permanently eclipsing us. A couple of years later, and we humans, having no real recourse, are mostly wiped out due to lack of sunlight. ]
[Question] [ My main character is based on the basic concept of a vampire. That she needs blood to survive. She was genetically engineered to digest ‘blood’ instead of eating. She still needs to drink water. Where she varies from a vampire is that it isn’t real blood, it just mimics the idea of it, so it’s basically a synthetic replica with different doses of nutrients suited to her etc. Although, she does eat some human food and drink now and again when she fancies and she smokes. This is possible because she still has all working internal systems just like a human etc. But where would she get her energy from? Because a human eats food for energy to perform basic functions. Would it be possible to obtain it from her ‘blood’? [Answer] # From the calories in blood According to fitbit.com, 100 g of lamb's blood has 75 calories. I'd imagine the USDA hasn't done any studies on human blood, them not being vampires and all. To get 2000 calories a day, you would need about 2.6 kg of blood, which is about 2.6 liters. A human has about twice that, so a vampire would need to kill and drain a person every two days, which sounds pretty reasonable and in line with the vampire mythos. Also consider that you only need to burn 2000 calories if you are doing normal human activities for 16 hours a day. If vampires are into sleeping in their coffins, which I hear they are, they might be much less active and require less calories. On the other hand, turning into a bat and exerting super strength sounds pretty calorie intensive, so lets call that a wash. [Answer] If you were to live only on the blood of your "prey," as a predator you'd need a lot of it. Just look at it this way: A regular predatory animal spends its energy resources on hunting prey and eating them entirely, including consuming the blood within the flesh. A predator like that mainly survives on the flesh, as the blood does not contain enough calories to sustain its body and behaviour. Though blood contains lots of nutrients, it will not replace the energy a predator spends when it hunts. Wasting all the energy that could be gained from the flesh of already-hunted prey would be extremely inefficient. The only living beings that live on blood are insects and small animals. And they live off of much larger animals. A human could not easily find something to suck blood from without killing or fighting it. It would have much higher energy expenses and would be very inefficient. Killing the prey and eating it, including the blood, is a lot more efficient. Some science The body needs 5.3MJ to 5.7MJ to replace a litre of blood. So we can say that's the maximum amount of energy it contains. The body's production of it is not 100% efficient and energy is lost during production. Also, no digestive system is 100% efficient. A calorie need of 2000 kcal (8.4MJ) per day is a good guess for a woman. So you would need at least 1.5 Litres of blood per day (calculated with maximal energy - though unrealistic because of energy losses). If you think that such an amount of synthetic blood is realistic, then it works. But that amount is unlikely to be achieved in a more natural way without killing anybody. Your synthetic blood could be made to contain more calories so she would need less. But that's up to your story. [Answer] If the artificial blood has all the nutrients a human body needs, you already have your energy. It's not different from only eating Soylent or any other of those full meal replacements. [Answer] Milk is a liquid food that can provide complete nourishment for mammals. I went through an eggnog phase myself. I guess that makes me an eggnog vampire! Happy Holidays! [Answer] "She still needs to drink water." - It's funny how many times this trope can be found in fiction, considering how much water the blood itself actually contains (roughly half of what makes up blood is water). If anything it should be the exact opposite: a vampire should need blood to survive and also non-liquids to supplement the diet. And this actually holds true for real-world mammal hemophages (I'm explicitly excluding insects here) such as the vampire bat. If your setting doesn't allow for magic, then you should make your vampire supplement her diet with normal food. That would actually be quite original, I think (I'm a fan of vampire stories and have yet to find one where normal food would be just as necessary for a vampire as blood is). Edit: couldn't find a source for my statement that the vampire bat needs non-liquids in its diet, so please take it with a grain of salt [Answer] Blood (real one for sure, so presumably also "synthetic" one) has a very high amount of nutrients in it. There are several ([real](https://www.nationalgeographic.com/animals/mammals/c/common-vampire-bat/)) creatures feeding exclusively on it. There's no difficulty in "getting energy" from it. P.S.: We eat to get a lot of things, including building materials, vitamins, oligo-elements etc., not just "energy" (all of them can be found in blood). [Answer] In addition to obvious and very good answers based on the fact that the blood is actually the thing which distributes energy throughout the body in form of lipids and sugars, You can, if You will, go more wacky. Let's see (pardon my tongue in cheek tone, would you? ;) )... 1. The vampire consumes the victim's soul along with the blood. First, we have to assume that a soul actually carries some free energy. Since it takes between 15 to infinity years to create an adult human (sadly, most people never really develop) and throughout all those years a LOT of energy is consumed by the brain - which in turn is the machinery in which the software called soul resides - i think it's a safe assumption. Further more, we can bring up an old STEM joke: [Exam question: Is hell exo or endo thermic?](https://www-users.cs.york.ac.uk/susan/joke/exoendo.htm) Having been convinced that soul carries some thermodynamically usefull energy, we are now safe to say that a vampire with ability to devour it along with blood could get energy it needs from it. And think about all the other ploot hooks this brings! PROS: Lots of possible plot hooks. CONS: You can end up with a bit too many voices in Your head if You retain those souls and dont devour them completely. 2. In far cyberpunk dystopian gloomy raining future, humanity has perfected and miniaturized fusion reactors to pocket sizes - and vampires use them. So, the basic idea is that all the energy calculations presented in other answers assume your normal average door-to-door biochemistry. But there is a loot of room down there, and lot of energy too. If You'd care to check, You'd find that biomolecules contain a LOT of hydrogen. So, screw normal biochemistry, trash glycolysis and throw mitochondria to a bin of history. Your vampire has a biochemical cycle which rips any and all hydrogen atoms it can find in Your food and provides them to a miniature fusion reactor in your chest, which produces all the energy You'll ever need. PROS: You're cyber-vampire-tony-stark CONS: Staking You could trigger a nuclear meltdown? Hm, maybe that's a pro too... 3. Thanks to combination of really eldritch, ancient astral magic and possibly some Quantum Field Theory You either have magnetic monopoles or naked singularities in a catalytic center of a digestive enzyme Fusion is nice, but let's go for E=mc^2. By a combination of exotic physics and magic You literally turn ALL matter of the blood You've drank into energy. Just like that, a molecule comes in, a lot of very very energetic gamma photons come out, then You just harvest them. PROS: You are better than sun in terms of energy production efficiency. PROS: You probably could shoot gamma rays CONS: A horde of physicists stalks You all the time to make measurements and possibly kidnap You and make their lab rat CONS: You leak photons. A real lot of them. [You're sparkling.](https://warmsandybeach.files.wordpress.com/2012/04/sally-hansen-04.jpg?w=318) [Answer] From your description i'd say with her syntetic blood she would be feed(have energy). Us humans actually don't digest 100% of our food so she could "eat" normal food just for the taste or to blend in but at the end of the day, it would have no nutritional effect. Alcohol should have effect on her(coz it's not broken down in our body either it just sticks around in our blood until it gets eliminated) and same for smoking and most drugs. [Answer] Make the synthetic blood closer to gasoline in chemical structure and energy content. A gallon of gasoline has [31,500 calories](http://home.dejazzd.com/kgard/bcn/calories_in_gallon.html), so for a 2,000 calorie daily diet, your vampire would only need about 8 ounces (1 cup). To justify their enhanced speed and strength, you might want to double that consumption level to 4,000 calories/1 pint per day. A pint a day keeps death at bay. ]
[Question] [ I recently started to wonder how an animal could evolve a gun. So I decided that here was the best place to find people that are smarter and/or have different ideas than me. * This creature has an endoskeleton, about 1ft (30cm)tall, 1ft (30cm)wide, and 3ft (1m)long without the neck. * Its neck is 1ft(30cm) long and very flexible to watch for predators and aim the gun. * The tail takes up 1ft(30cm) of the body and is used to keep balance when rearing on its back legs to intimidate predators and/or a mating competitor, and reach food from higher places. * The creature can swim well enough to not drown in the water, and cannot run faster than about 15mph(24.14kmph), and it can't climb or fly. The gun cannot be a limb that picks up an object and just throws it like primates do, but have a mechanism that shoots it at least 6.5ft(2m). How would the animal actually shoot something at its predator? [Answer] So, what you've described (whether intentional or not) sounds eerily similar to the Tyranids from WH40K and their Bio-Weapons: [Details here](https://warhammer40k.fandom.com/wiki/Tyranid_Biomorphs) In the Lore - there's different types of Ranged bio-weapons, from Acid firing rifles (think like a spitting cobra, but on steroids) to the Deathspitters (which fire a living creature that has several nasty properties). However, as much as I love 40K, the biggest problem with this concept (and yours) is Range. A Muscle contraction can only produce so much force and spraying a liquid can only go so far - 10 metres is realistically your limit, even a modern flamethrower doesn't have a range much beyond 100 metres. Whereas a modern rifle round (say 5.56) is effective out to about 400 metres from a standard AR platform, with high quality ammo and a high quality rifle, you can get good groupings out to almost 1,000 metres. The key here is the pressure required to get a projectile to go that far - which is 55,000 PSI - simply too high for any biological system to contain (for reference the greatest pressure that any part of a Human can withstand - the Femur is less than 20,000 PSI). To conclude - So long as your 'gun' is only shooting at ranges of around 10 metres - some combination of Acid/Venom and a muscle contraction would suffice. But if you want something that approaches a 'real' gun, then biological limits mean you can't get and contain enough pressure to give a range equivalent to a firearm. [Answer] ### So how did it evolve? Other answers seem to be focusing on what the end point might be, but you asked how a gun could evolve, that is, what the stages of evolution could have been to result in a gun. First, take [bombardier beetles](https://en.wikipedia.org/wiki/Bombardier_beetle) as a starting point. [![enter image description here](https://i.stack.imgur.com/dr0zn.jpg)](https://i.stack.imgur.com/dr0zn.jpg) They can blast noxious chemicals from their rear ends as a result of a chemical reaction between hydroquinone and hydrogen peroxide. These chemicals spontaneously combust when they come into contact, providing the force to shoot out the payload. We may suppose that your organism's ancestors had a mechanism like this, shooting a liquid mixture at a relatively low force, to burn and poison predators at close range. From there, we can imagine that there could have been mutations that altered which particular explosive chemicals were used to propel the poison. More powerful explosive chemicals would produce greater range and higher temperature, which would be more effective at deterring predators. A more powerful explosion would also require a stronger blast chamber, so the ancestors of your gun-creatures would have evolved stronger materials to contain the blast (thicker bone, chitin) at the same time as they evolved more explosive chemicals. We could even imagine that if they lived in an iron-rich environment, like the [scaly-foot gastropod](https://en.wikipedia.org/wiki/Scaly-foot_gastropod), they could start to incorporate iron into their blast chambers, making them even stronger. From there it's not a stretch to imagine that one of the ancestors of the gun-creatures happened to grow a bony protrusion at the front of the blast chamber. This protrusion would break off from the force of the explosion and could have helped to injure the predator at greater ranges, in addition to the poison. It would be the precursor to the bullet. From there evolution would be a straightforward process of improving what's already there: * More and more powerful reactive chemicals until the animal naturally produces something like gunpowder * Stronger and stronger blast chambers to contain the explosion * Improved shape of the blast chamber and bullet, towards something like a rifle barrel * The ability to regenerate the bullet (as well as any damaged parts of the blast chamber) after it is fired * Gradual loss of the vestigial poison component of the payload, in favor of an increased explosion for a faster bullet * Eyes and brain structures to help aim the bullet more accurately at range By the end of this process, the creatures could have something similar in range and power to a musket, though it would be single-shot and they would have to take time to regenerate the damaged blast chamber and lost bullet afterwards. What initially was a last-ditch defensive tool against predators has become something much more powerful and efficient, so that the creatures may evolve to become apex predators themselves. [Answer] ## PENISES This is an example of Nature did all the hard work for you. A gun is, essentially a tube of some length from which a projectile is expelled at some velocity. Every male on the planet knows about this and has almost certainly given the thing a try. So, what is a penis and how does it work? Well, it is, essentially, a tube of some length through which a couple different kinds of projectiles are expelled with force. The evolution of your creature on its path towards weaponising this arrangement would involve two components: musculoskeletal and saccular. Skeletal: I would suggest that a bacculum be already in place and that the penis thus be permanently rigid. This would allow the creature to engage its weapon at any time without the need for reproductive signalling to occur. Musculature: There are already muscles in this region, but your creatures will be evolving muscles that more forcefully expel the projectiles and more energetically rotate the penis around its axis along with improved nervous systems that allow for penis-eye coordination for aiming. Saccular: Your creatures will evolve one or more bladder analogue structures that produce some sort of material for use as a projectile. A strong acid, for example, perhaps in conjunction with a sticky mucus. These three components could arise from some reproductive or excretory precursor system. A new and better use has been found for these early precursor systems and are now widespread in the population. The advantage here is that all the structures are already in place in the likely mammalian creature you propose: it doesn't require any massive physiological overhauls or involve invertebrate solutions. [Answer] I imagine any answer will require a decent amount of handwaving. The two methods I could think of would be a biological spring, or two chemicals that when mixed together produce a large amount of gas. The idea for a spring-powered projectile launcher is inspired by [this](https://www.smithsonianmag.com/science-nature/this-insect-has-the-only-mechanical-gears-ever-found-in-nature-6480908/) insect that has evolved gears, which to me puts the idea of a powerful biological spring into not-totally-implausible territory. The idea for the creature having stores of two separate chemicals that it mixes to produce thrust comes from the [bombardier beetle](https://en.wikipedia.org/wiki/Bombardier_beetle), which does the exact same thing to expel boiling hot fluid at other insects. With some handwaving, its possible your creature could expel these two fluids into the 'barrel' of the gun, which will accelerate the projectile and cause it to shoot out. Another important consideration is the projectiles. Your creature will either have to grow the projectiles itself, which would likely allow for better aim and range (as you could argue evolution caused the projectiles to take on an aerodynamic shape) but would make ammunition far more valuable, or it could suck rocks up into the barrel, which would result in poorer aim and range, but much cheaper ammunition and the potential for scattershot. [Answer] ## Use a scaled up nematocyst A nematocyst is the tiny harpoon like structure used by jellyfish to sting thier prey. A nematocyst is basically a biological spring that is compressed inside of a fluid sac. To fire the nematocyst, the jellyfish inflates the sac with extra water pressure causing it to rupture when this happens, the spring is both launched out by the pressure build up and it decompresses causing it to spring out ejecting at an acceleration faster than a modern riffle... now, part of what makes nematocysts so darn fast is that they can take full advantage of the the square cube. If you were to scale a nematocyst up to the size of a gun sized weapon, material science becomes very different. Since you are working with an endoskeleton animal, a similar structure could similarly evolve to use a horn like material. Based on what we know about actual spring weapons made by humans from horn, we can predict that a spring loaded horn weapon could fire at speeds ranging from 200-300 feet per second giving you a weapon similar in nature to a recurve composite bow and arrow. ## How it might have evolved Imagine an animal similar to an impala. It's horns already have a generally spring like shape. Now imagine if a mutation caused these horns to be overgrown with a sinuw layer that keeps it from breaking skin, and instead compresses it. Then when a predator tries to eat it, the stress causes a build up in blood pressure causing the horn to rupture the layer stabbing the would be predator as it tries to bite the back of the mutant impala's neck. Evolution does its things and this becomes a dominant gene. Over a few million years, these horns become more specialized springs. They reorient forward so they can be used more offensively, and as they get better and better at springing out, they start breaking off sometimes when they spring out... which gives them more range so again they continue to evolve until they are designed specifically to fire off at will. [![enter image description here](https://i.stack.imgur.com/oLCs6.png)](https://i.stack.imgur.com/oLCs6.png) [Answer] You've got loads of options, most of them unfortunately painful for the creature in terms of recoil and side effects unless buffered by an insensitive and durable shield of hard tissue, for example a bone mass used as a launching pad. For mobility's sake, the back with a hard shell makes the most logical location for shielding the creature from the recoil of its own projectiles if they are powerful enough to pack a punch. It could also jettison parts of a limb at high speed and and regrow them. Whether digits, tail, back or any other location, a bowl-shaped bulwark of durable tissue is required to prevent significant self-damage. Propulsion offers many methods, each with significant constraints. ## Air power The creature could use [pneumatic chambers within the skeletal system](https://blogs.scientificamerican.com/laelaps/secret-air-sacs-made-this-dinosaur-extra-light/), like some dinosaurs have. The creature can channel high pressure into a launch site by flexing its body in a way that pinches or seals pneumatic valves. Once released, the membrane covering a given exit must seal and regrow together with the projectile, after which it can be launched again. Likely no soft tissue can withstand high enough pressure to reuseably launch a projectile at lethal velocities. ## Leverage The creature could have an internal mechanical "arm" that loads and launches grown spines from a glandular magazine using the end of a long lever bone flexed with a strong but short muscle around a short rotator to achieve high velocities through a curved bony guide similar to a partial gun barrel. <https://en.wikipedia.org/wiki/Spear-thrower> ## Explosions Yeah, chemistry. A pair of glands mix reagents or a spark is provided to a fuel reservoir which ignites or expands a gaseous substance rapidly to launch pebble-like growths at an adversary. [Answer] Considering the barrel pressure, your creature probably won't be able to fire regular bullets But you could try the [Gyrojet](https://en.m.wikipedia.org/wiki/Gyrojet), where instead of firing bullets, your creature fires very small rockets However, the accuracy of this bullet type is very poor and your creature may need to be a pack hunter to use it effectively [Answer] Lots of discussion here around bullets and chamber-pressures, but what if we looked at the real-world for inspiration? ## [Gyrojets](https://en.wikipedia.org/wiki/Gyrojet) I love gyrojets. They're the answer to a question we didn't ask. "What if we made the bullets rocket-propelled?" There are a few major advantages to rocket-propelled bullets. 1. Low muzzle-velocity 2. Next to no firing-chamber pressures, you can launch one from anything that can withstand the heat for a split-second. 3. They keep accelerating as long as their fuel holds out, so they can exceed conventional bullets in their calibre very easily with the right fuel. Your creature grows biological gyrojet bullets and launches them from a specialised horn-like organ. The mechanism would be somewhat like growing an egg, [![enter image description here](https://i.stack.imgur.com/bG3l6.jpg)](https://i.stack.imgur.com/bG3l6.jpg) Each projectile would be complete in and of itself. A spike of bone with a hollow section full of a powerful rocket-fuel-like substance. The "firing chamber" would consist of a pair of glands which secrete chemicals that burst into flame on contact. This is essentially the same as the Bombardier Beetle (mentioned elsewhere) and various other insects with similar capabilities. If they do this when there's a projectile in the chamber, the projectile ignites and immediately launches as a rocket. Its muzzle-velocity would be pretty piddly, but at a dozen meters away it'll have reached bullet-like velocities and be lethally dangerous to anyone not wearing a bulletproof vest. The creature with a biological gyrojet launcher is probably not going to achieve the same velocities, range and accuracy as a machined weapon, but imagine a nest of them.. A predator sneaks up on the nest, knowing that their guns aren't very dangerous at close range. Then it gets taken out by a sentry lurking in a tree 20 meters away. The minimum-range limitation I think would add to your worldbuilding quite well. [Answer] The animal could have a similar mechanism to the sandbox tree, which has fibers that contract and create a lot of force until it explodes / shoots out. That mechanism can of course be more complicated and involve several organs to create a bone projectile, a barrel bone, fibers and maybe even explosive gas, which all aid in creating and shooting a projectile. EDIT: As requested I'm adding a possible option here One possibility could be that the animal has a barrel shaped hollow bone. This bone has a mechanism (muscles and fibers) to "load" the bone with a bone / shell projectile. After the projectile is loaded the body starts to produce an organic explosive which is the "gun powder" in that case. The primer could be some small organ or part of an organ, which gives off a shockwave or electrical signal to detonate the explosive. Such a mechanism would obviously not make the animal able to fire like a machine gun but it is realistic that it could fire a couple bullets per day (It would need to consume a lot of resources including the materials needed to create projectile and explosives tho. Most likely it'd need to actually devour the bones of its victims for the minerals) [Answer] This is probably a comment more than an answer, but given that no one else has bothered I feel compelled. Allow me to introduce you to the [bombadier beetle](https://en.wikipedia.org/wiki/Bombardier_beetle). This little bug has evolved an interesting defense mechanism. It shoots hot steam out of its but, produced by some interesting chemistry involving hydrogen peroxide, a few organic catalysts, etc. You can read the link for details if interested. It's basically your gun, as-is. We need to scale it up, and we need to put a bullet and barrel into the mix. As we extend the chamber for the gas to be expelled from it will give us a bit more velocity and accuracy. This could be made of any of a number of biological substances. Bone, horn, even something closer to what we find in teeth. And the bullet could be made of nearly any of the same substances, as long as they're relatively fast-growing. It may have to go days between "reloading", given the biological nature of the ammunition, but even venomous snakes are reluctant to bite for concern that they might not have enough later when they might need it, right? Evolution has already delivered a solution to your problem (or at least a prototype). It only took 4 billion years or so! [Answer] Just here to add something (to be honest, I didn't read carefully all the other answers so if someone else already talked about this, I'm terribly sorry). It's amazing how Nature always finds a way (Jeff Goldblum anyone?). There exists a kind of shrimp that evolved a small, but very powerful, spring-action powered hammer (with a very complex assortment of bones, tendons and muscles). The scientific name is Gonodactylus smithii if I'm not mistaken, commonly called purple spot mantis shrimp. I've seen it in documentaries, the bigger ones can generate a force up to 1500 Newtons. Regrettably, the english wiki is terribly lacking in information about it, but you should be able to research more about it with the information I've given (It's all I know about it). From there, I would think it's only a matter of figuring a way to create a projectile (could be a piece of regenerative bone) and some barrel-like structure to transform this friendly shrimp into a long-ranged shooting beast. Give it eagle eyes for accuracy, and you're basically done. The data is extracted from my memory from the documentary I mentioned, so It would be wise to double check the numerical information, but nevertheless it is the strongest force generated by any natural animal mechanism. Hope this helps! [Answer] Following on to many of the others, I would go with the bombardier beetle analogy as far as propulsion. For the chamber, lots of creatures generate crystal structures, and the snails that incorporate iron into their shells have already been mentioned. Carbon is one of the most readily available elements; if we're hand-waving anyway, why not a creature that can secret a carbon fiber lattice of some sort? As to the actual projectile, chicken gizzards may make a good answer. Chickens (and other birds, I'm sure) eat rocks and gravel to assist in digestion. Your creature may do the same thing to provide ready bullets. And maybe if it's out of internal bullets, it just picks another one up and stuffs it in the hole. Maybe the carbon fiber lattice is flexible enough to allow its musculature to adjust the fit for any random rock within a given size range. [Answer] <https://en.wikipedia.org/wiki/Love_dart> Some things like it exist in nature already, years of evolution could lead to strengthened muscle to deliver at greater ranges. <https://thekidshouldseethis.com/post/exploding-plants-spread-their-seeds-with-high-pressure-bursts> ]
[Question] [ [![black and white image of a vehicle with six legs in place of wheels, vaguely resembling an arthropod.](https://i.stack.imgur.com/d4Tll.jpg)](https://i.stack.imgur.com/d4Tll.jpg) The commissioned mech-tank hybrid, pictured above, is a core component of a story I'm writing and I'm still not sure of some of it's specification. Things like weight and mobility, and I'm stuck trying to make it somewhat realistic for my readers. [Answer] There are a few hexapedal gaits that have been used in robotics. Wikipedia [lists](https://en.wikipedia.org/wiki/Hexapod_(robotics)#Locomotion) Alternating tripod, Quadruped, and Crawl (move just one leg at a time). Insects use the alternating tripod, which is stable because tripods are stable, and is good for covering rough ground. The fastest (not most stable) is described [here](https://spectrum.ieee.org/six-legged-robot-oneups-nature-with-faster-gait). Direct link to the video [here](https://invidious.namazso.eu/watch?v=QZt3eJzHLSU); the summary is that it's quicker to bounce on two legs at a time, which yes brings the body up off the ground quite a bit. [Answer] Generally speaking, the lower the center of mass of a moving object, the lower the risk of it flipping when changing direction. Translated to a vehicle, if you want to make a sharp turn, the lower the center of mass, the quicker you can turn, all the rest being the same. This is why race cars are as low as possible and trucks sometimes flip over when turning too fast. You can try a little experiment by yourself: put an empty plastic bottle on a tray and walk fast with the tray, then turn sharply. You will see that it is easier for the bottle to fall when it's laying on its short face than when it's laying on the long face. In your case, the lower you can keep it, the faster it will be able to change direction. Since I assume you are not planning for having your mech going always and only straight, keep it low. [Answer] [As L.Dutch stated](https://worldbuilding.stackexchange.com/a/241777/72352), for turning purposes a lower profile is needed. However for realism, I'd say speed is by far not the only thing to be concerned about! Also consider the following points: * Keeping a small (dense) profile to present less surface area to be hit by enemy fire. * Keeping low so the vehicle can take advantage of terrain variations to lower its visibility to enemies. * A wider stance is more stable and precise when firing heavy ordinance. * Spread out legs will be more stable in less ideal terrain conditions. * A higher profile could be faster and possibly easier on fuel. This will all have been considered by the engineers, so the lower stance would most likely be default with different stances available for higher profile situations. [Answer] Its faster high up, slightly bend legs. For turns you can always go into a lower stance if necessary, but considering the legs are already supports farther away from the main body it seems kind of a mute point. With the legs bent you reduce the maximum length of a single stride. So unless you stretch the legs almost horizontally, which I don't recommend, the stride length will always be smaller if you use a lower stance. Additionally it is more likely to be slowed down by terrain if you use more horizontal legs. So stand tall! Until your speed is less important than your visibility that is. Also since people may bring it up: dont shoot the legs! Unlike tracks or wheels you can put armor on them entirely (even if its light armor) and the legs are the most erratic moving parts of the vehicle. If anyone tries to shoot them, have them shoot where the legs meet the chassis. [Answer] For an alternative idea, check out the [Tachikoma from Ghost in the Shell](https://ghostintheshell.fandom.com/wiki/Tachikoma). The core idea is they have multiple legs (only 4 in the canon but no reason to not go to six for larger models) but each leg has its own wheel, presumably driven by independent motors (just like some modern electric cars have a motor for each wheel). This means they can walk when needed, but also just drive at high speeds. [Answer] TLDR: If the legs are completly stretched out, no. If the legs are closer to the body and the body is closer to the ground, it would walk more efficiently and with greater force, but slower. However, you could use the back legs to move forward like a jump, like bird-like creatures do or grasshoppers. --- I would suggest you to look up subjects about [torque](https://youtu.be/T99yH_gw3p8) and [mechanical levers](https://youtu.be/eTa2EFd3JF0). In short, the human body (and other animals aswell) is composed of "biological levers" that work with a certain amount of mechanical disadvantage most of the time. [![Illustration of lever systems found on the human body](https://i.stack.imgur.com/jZaDt.png)](https://i.stack.imgur.com/jZaDt.png) (I couldn't find any examples with insects, unfortunately) The same is applied to wheels and for mech legs. If you put the legs of your mech far away from the mech's body and walking very low, the extended legs would work like giant levers, the same could be said about fully extending these vertically. However, just like Marky stated in the comments: humans walk efficiently by falling and catching up over and over again. But I don't know if such walking cycle would work for a 6 legged creature. So, if you know about mechanical levers, the tip of the legs will move faster, but with much less force, since the speed of movement is related to the torque and RPM of a car or, in this case, a mech, then it wouldn't go very fast, but it would lower its profile on the horizon. However, the back legs would be able to work better if these were used to step as close to the body as possible and then pushing it forward. It would work just like a grasshopper or a bird jump/walking, and the other legs could be used "just" to keep it from falling instead of actually making a lot of effort to move. [![Illustration showing the working principle of a bird leg](https://i.stack.imgur.com/jVmwb.jpg)](https://i.stack.imgur.com/jVmwb.jpg) (sorry for the big illustration, I couldn't find it in another resolution) Unlike what people think, the bird-like leg is not actually a leg, it is the bird's ankle, the actual knee is closer to the body than to the ground. It is like they are perpetually on the tip of their toes, not particularly comfortable, but certaintly easier to run very fast. So, the distance from the thighs to the ground could be seen as more or less a straight lever to the ground, if the ankle is centered to the axis of the thighs. It would be like crouching before jumping or running, you could put way more energy in the movement instead of your normal walk. You could use such mechanism to walk forward, but eventually the back legs of your tank would still need to fully contract, it could be with the kness moving laterally or vertically, as long as the inital and middle movement part are closer to the body, such as the bird example. [Here is a video of a flea jumping in slow motion](https://youtu.be/psbNbTpsprU), its legs are similar to bird legs. Of course, your tank wouldn't fly as high as a flea, but it could move forward more efficiently and faster. And the same can be applied to grasshoppers. [![Photo of a grasshopper](https://i.stack.imgur.com/PxmTL.png)](https://i.stack.imgur.com/PxmTL.png) (The back legs of your hexapod tank are already pretty "grasshoppy" for this mechanical movement) [Answer] The effect of long legs is the same as riding a bicycle: it requires generally more effort to move them if uphill but about the same or less on flat terrain, and if the legs move with the same angular velocity at the body, the speed increases with making them longer. It may require less energy to move with longer legs because this means less steps, and the step likely to include additional activity not relevant to pushing forward (lift the leg up for the step, reverse the direction, and the like). Hence a really fast robot I think should have long legs, as much as practical. There is such a term as "bicycle step", how far do you drive on one revolution of the pedals that is roughly equivalent to one step of walking. It is many meters, hence cyclists are much faster than walkers. However, the longer the legs, the more difficult it will be uphill. Also, the creature gets wider and may not easily pass everywhere. ]
[Question] [ The world I'm building is similar to medieval Europe but with magic and dragons. Instead of riding horses knights ride dragons. I wonder if it possible for a medieval country the size of England to provide for five hundred dragon knights with only limited help from magic. Note that the average dragon should be the size of Drogon from Game of Thrones. Magic is used to heal any wound or sickness that can kill any cattle and sheep or make them infertile. So cattle and sheep only die of old age and should all continue breeding till death. However, magic is not used to make them breed any faster than normal. Drogon's size: wingspan 48-60 yards or 44-55 meters. His body is 40 feet long. 87,500 pounds. Dragons can hibernate but must awaken for one full day every two weeks both to feed and to exercise so as to maintain muscle mass. [Answer] It looks like no, not if they are carnivores, but it is possible if they are omnivores There is a nice [helpful calculator](http://www.world-builders.org/lessons/less/biomes/annutrita.html) for this. So if your dragons metabolism is comparable to a dinosaur or mammal you are looking at roughly about 1,039,878 kilocalories a day, per dragon. With 975 kilocalories for a pound of beef, that is ~1067 lbs of beef, or roughly 1,778 lbs of cow (only about [3/5th of a cow's](https://www.oda.state.ok.us/food/fs-cowweight.pdf) weight is "food" aka not bone or skin). A medieval cow weighed about [75%](http://www.personal.utulsa.edu/~marc-carlson/history/cattle.html) of a modern cow and a modern cow weighs on average 1,390lbs (so medieval would be 1,045lbs). So that is roughly 2 cows per day per beast or 730 cows per year per beast. Now what does this mean for your kingdom It takes 1.5 to 2 acres to feed a cow/calf pair for 12 months and takes about 2 years to raise a cow to slaughtering age, \\so to feed your beasts for 1 year, you need 1460 acres of pasture That is roughly 1 large barony (of half one on the small estimate) just devoted to feeding one animal. For 500 dragons we are looking at 730,000 acres) Now England contained roughly 43 million acres of farmland today, so it is indeed possible, but you would be looking at 1.6% of the total farm land, and that is modern farmland, BUT a lot less would have been farmable during medieval times, medieval england only had approximately 8,000,000 acres of farmland (according to the domesday survey) that would mean you are using 9% of your total farmland. This is where the estimate gets a bit sketchy pastureland is not the same as farmland but at the same time the medieval farming systems were only capable of utilizing about half the farm land at any given time. Either way thats a huge amount of food, probably more than they could spare. ([estimates](https://worldbuilding.stackexchange.com/questions/20826/what-percentage-of-a-population-can-be-part-of-a-medieval-military) are medieval communities could only spare about 2% of their food production for the military. Conclusion So in the end you might well be be starving your farmers to feed the dragons. At the very least would have very little else including no other military or aristocracy, which means their country would very quickly fall apart because it can't feed it's own government. EDIT alternatively if you go with Will's idea and say they are herbivores (or omnivores) you are looking at only ~200,000 acres to feed all of them, that much more reasonable, double the acreage and say they get some meat/fish with each meal and you have something with a noticeable impact on the kingdom but not a prohibitive one. [Answer] It all depends on how "realistic" you want to make your dragons. Quite frankly, reality takes a back seat when discussing this topic, because flying, fire-breathing beasts that large are not actually feasible. The amount of food that a large specimen would need to consume to survive, let alone engage in strenuous physical activity such as almost daily training, etc. would be insane, and I seriously question the ability of a medieval nation to keep up with the requirements. However, since these are magical beasts, there's no reason why they shouldn't be able to subsist on magic itself. I would probably make it such that dragons *love* meat, and are consummate carnivores, with the caveat that eating even a whole cow does not provide nearly the amount of energy that dragons require. Which is why *traditionally, dragons spend decades hibernating, emerging only to gorge, and then retreating back to their dens. Dens which they take great pains to stock with magical items they pillage from their hapless victims. They then slowly leach the magical energy from those items over time, thus surviving for decades without having to venture out to hunt. The very first dragon knights realized that the large piles of gold and gems that dragons are found resting on are not valuable to the beast in and of themselves, but were once a critical source of magical energy! Armed with this knowledge they eventually tamed the first beasts. The way that modern dragon fleets are maintained, is by having mages enchant dragon pens/harnesses etc. such that the dangerous beasts have a steady source of "food" available, thus remaining awake, and cooperative. [Answer] This dragon is huge! A WW2 B29 super fortress only had a 43m wingspan. Of course any flying animal of that scale would be impossible in our world, but since you are using magic I think we can let that pass. If you still want to do some sort of realistic-ish calculation without resorting to magic feeding as well as magic lifting, then you need to know the weight of the beast. Taking a [flying fox](https://en.wikipedia.org/wiki/Grey-headed_flying_fox) as a model – not that accurate but this is a rough calculation to say the least and the data is available. 1m wing span and 1kg in mass and assuming an average density of 1kg/litre of animal. As volume increases with the square of size a creature 50x the size would weigh in at 50 cubed ~125 tons (166tons for a big one) Animal food requirements very roughly ([from here](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4683169/)) say 10,000kJ / 100kg / day so a 125,000kg animal would need 1250 x 10,000 kJ / day = 12,500,000 kJ /day At 7570 kJ /Kg (for beef) so 12,500,000/7570 = roughly 1.6 tons of beef per dragon per day. At 400 Kg per cow (assuming lighter weight cows from years gone by) that’s 4 cows per dragon per day. For a …flock? Of 500 dragons that’s 2000 cows per day. I don’t think its manageable. Solutions – use magic, have fewer dragons, have smaller dragons, keep the dragons resting for a large part of the time so minimising energy expenditure might cut the requirement by a lot x0.25 perhaps? Breed larger cows like today – maybe 1000Kg could be doable, use extensive ranching on a huge scale. [Answer] If dragons existed naturally, then their food supply also existed naturally. I think you have to go through the entire chain before wondering whether humans could support them. How did they live before the humans tamed them? If they lived in this world, save for dragons and magic, then they must have necessarily lived far apart, and spent several hours a day eating small meals over a vast territory. Otherwise they would essentially strip the land of animals and have to move on. But if they lived far apart and had a huge range (so as not to outstrip their food source) then they didn't reproduce very frequently. Which means they can't adapt. But this then raises the question of how the evolved into such large creatures and survived anyway - what's the evolutionary advantage to a creature that reproduces infrequently, takes up a huge amount of space, and eats vastly more food than any other creature? Typically in evolutionary systems you'd find carnivores are physically smaller (though more powerful) than the herbivores they eat. I'd suppose that instead there were other very large herbivores in the world that had a high enough reproduction rate and a high enough mass gain rate that they could supply the needs of the dragons. But then either they died off or they are still around. If they died off, then the dragons had to change strategy quickly to survive (ie, had to be somewhat intelligent) as a species because there's no food source to replace theirs with. Perhaps they became more territorial, and then started reproducing less frequently (due to territory issues and finding a mate requires leaving one's territory). Otherwise the huge herbivores must still be around. They must reproduce frequently, grow quickly, and consume tons of grass daily. So if you don't want to magically feed your dragons, your best bet is to invent their food source as well - huge cows. The only remaining issue, then, is that there's not enough land in the UK to grow enough grass to feed the herbivore herd sufficiently to maintain 500 dragons. So make the "huge cows" sea creatures, and make the dragons fishers. This is necessarily limiting, as the dragons then must live near a coast, but the sea can hold and feed huge creatures, and if the dragons can feed like certain birds, searching for signs of whales, diving, and pulling them out of the water to feast on nearby land, I'd say it passes believability muster. [Answer] First: I think there is an order of magnitude problem in the OP weight given. The dragon is said to measure 40 feet and weigh 875,000 lbs. That is 396 metric tons. A blue whale is 100 feet and 173 metric tons. A sauropod is between 80 and 100 metric tons and many of them were longer than 40 feet. Let us assume this was supposed to be 87,500 lbs or 39 metric tons. That is a medium sized sauropod. It is still nearly 3 times the size of a T.Rex. The problem is that these dragons are too big for meat eaters. The solution: they are not meat eaters.* [![marine iguana with big dreams](https://i.stack.imgur.com/sgQQb.jpg)](https://i.stack.imgur.com/sgQQb.jpg) <http://www.birdsasart.com/brightideas/marine%20iguana%20showing%20teeth%20_w3c7795%20%20punta%20espinoza,%20fernandina,%20galapagos.htm> Iguanas are awesomely dragonlike. They have spines and claws and sharp teeth. If you mess with them they will definitely bite you and take off a chunk. And spit it out - they are vegetarians. So too your dragons. They will do all the dragony type stuff you need and then mow their way through swaths of swamp and forests. And kelp beds, like this marine iguana whom I think would be an excellent dragon. I will point out that vegetarian mounts for knights have some precedent. Feeding grazers and browsers off the fat of the land also has precedent. Vegetarian dragons consuming huge amounts of low quality plant food would produce huge amounts of dung which offers the possibility of a different sort of aerial attack. I will also humbly suggest that dragons endowed with a rumen would produce methane, which offers a plausible method that they might breathe (burp) fire. [Answer] My kids and I tell stories to each other where the dragons all just eat metal (hence their habit of eating knights and treasure). Another option is to have your dragons eat lots of seafood. Lots of meat on a whale... [Answer] I think the answer is likely "yes". A [Spinosaurus would likely have been 41-50 feet](https://en.wikipedia.org/wiki/Spinosaurus). This is larger than your dragons. And while it is possible that these were fish eaters, there are plenty of other species of primitive carnivores. Could they survive in England, specifically? I'm less sure about it. From Wikipedia is not clear how many a given region could support (exercise left to the reader). It is significant that a predator of that size requires there to be prey of similar size — it takes a lot of effort to hunt, if a predator has to hunt constantly, that will lead to a net decrease in size. Of course, if these predators are being fed by humans, then they could theoretically get bigger. If I were creating a world with dragons, I'd also create giant tree-eating herbivores while I was at it. The benefit of the tree-eaters would be that they would not take up valuable land for crops (keep them in the fallow field, near the woods), they would provide plenty of fertilizer, and they would give plenty of meat (for both the dragons and the people) without needing to sacrifice valuable grain-growing land. (The need to surrender croplands for animals actually caused a few problems in the Middle Ages, this would probably provide meat for cheap). I think your biggest concern would then be how to prevent the apatosauruses from trampling the azaleas, and the dragons from eating your neighbor's dogs. ]
[Question] [ There are some pieces of media in which a city borders a wasteland that remains after nuclear apocalypses. The border is usually some kind of thick-tall-double-reinforced-anti-radiation-concrete‚Ñ¢ wall. [![enter image description here](https://i.stack.imgur.com/3YHZD.png)](https://i.stack.imgur.com/3YHZD.png) Does it help? My thoughts so far are below. The city exists, so there was no impact there. It means that there are no explicit sources of radiation inside. It means the threat is from outside. The worst thing that could happen is radioactive dust. The wall helps but just a bit. The wind can transfer dust to the city regardless of the wall. Radiation can travel through contaminated water. A stream or rain, for example. Wall does not help. Radiation can travel via building materials. Wall helps prevent people from obtaining such materials, but radiation is trackable. One can detect affected bricks or steel and discard them. If one can bring them in, then another can bring them out. Radiation can travel via animals. Wall helps, but how much radiation exposure will it prevent? Not very much compared with dirty rain or dust storm. Am I missing something or the wall should be much less fundamental? Instead of a monumental obstacle, it should be more like a fence with barbed wire. [Answer] The wall is not for the radiation! You can't keep out radiation with a wall. Plus the wasteland is only a little bit radioactive these days. Makes your hair curly. No, that wall is because you have got good stuff in your city of survivors, like hotties, and food, and gasoline. Out in the wasteland are desperate folks. Weirdos in metal masks on motorcycles. Mutants. Strange mystics with pygmy goats. People with cars that have spoilers so huge that they glide when they go over jumps. Yeah, those people. [![road warrior](https://i.stack.imgur.com/1SY5o.jpg)](https://i.stack.imgur.com/1SY5o.jpg) <https://www.sceen-it.com/movie/196/Mad-Max-2> The wall is to keep them out and keep your good stuff in where you and your fellow curly-haired hotties can savor it undisturbed. [Answer] Walls have never been useful against Mother Nature It's certainly true that on a calm day with no breeze a thick concrete or lead-lined wall can have value. In that one case radioactive particles are sitting on the ground outside the wall and the emitted radiation would be stopped by the wall. Now, I know we're comparing apples and oranges here, but to give you an idea of how little concrete alone is worth against radiation... > > To reduce typical gamma rays by a factor of a billion, according to the American Nuclear Society, thicknesses of shield need to be about 13.8 feet of water, about 6.6 feet of concrete, or about 1.3 feet of lead. ([Source](https://stemrad.com/cbrn-gamma-radiation/)) > > > Whether or not you need to reduce the radiation a billion-fold depends on how much radiation we're dealing with, which you don't explain. The odds are good that you don't need that much protection, but you're still needing to either line the wall with lead or have a stout, thick wall. Granted, if you put enough concrete in place, you'll eventually stop the radiation... but that's a LOT of concrete. There comes a point where the people of your apocalypse simply can't afford the wall. But keep in mind, we're only talking about a calm day. On any other kind of day a wall is worthless. That's because radioactive particles are carried on wind. And no matter how strong the wind, the particles being heavier than air, they fall. The greater the diameter of space the wall is protecting, the less valuable it becomes (or the higher it must be to make any difference whatsoever). You don't tell us how much area you're trying to protect, either. But, because the time of radiation exposure is more important than the fact of radiation exposure, the question is what's easier, clean-up that you must do regardless of the wall, building a higher wall, or protecting individual buildings? If you're trying to protect your people against radiation...\* ...what you're going to have is a fundamentally underground society. From a suspension-of-disbelief perspective, you could claim that a forest of [leaded glass skylights](https://mo-sci.com/using-glass-for-radiation-shielding/) to provide natural lighting to your underground community. But underground it will be where it can be shielded with lead-lined rooftops. Or, for the discerning homeowner, you could be half-underground, half-above ground with lead-lined (or unreasonably thick) walls and leaded glass. Thus, when the dust is blown in (and it will be blown in), it doesn't kill everyone. And yet that lovely view of the post-apocalyptic wasteland goes unhindered with your favorite Chardonnay. To answer your question: No, it doesn't help But that shouldn't stop you from using a frequently-used post-apocalyptic story trope. As I said in my comment: zombies. And people who might want to steal your lead. [Answer] Have three walls. # Have a tree wall. Dust storms can be blocked by plants. [Plants hold soil together with roots and block the movement of wind across land, making dust storms less effective.](https://news.unl.edu/newsrooms/today/article/fdr-s-great-wall-of-trees-continues-to-provide-lessons/) [Trees are more resistant](https://theconversation.com/why-plants-dont-die-from-cancer-119184) to radiation than animals, and this would serve as a first line of defense. # Have a concrete wall. This wall stops raiders getting in, keeps civilians from wandering out, and most importantly serves as a mount for the third wall. # Have a soft wall. You can use plastic tarp, leather, wood and oil, or a bunch of things. The key is that when there's a dust storm, or rad counters detect too much radiation in the wind, you cover up the city. The concrete pillars serve as mounts allowing you to quickly pull up covers. This means that most dust will either blow over you, or accumulate on the covers where expendable poor people can clear it off later. Most of the populace can hide behind thick concrete walls away from gamma radiation, while more risk taking people can ensure the covers stay strong and not much radiation gets in. They can pull back the covers and shake it clean it after the storm ends. A large central pillar can ensure that most of the dust will slide off, and not accumulate on the soft wall. [Answer] ## The wall is to keep people in. As other answers have pointed out, a wall wouldn't keep radiation out, and walls generally are much more useful against people (or animals) than against nature. Of course, one way you could do your story is to have the radioactive wasteland full of zombies, or mutants, or [reavers](https://en.wikipedia.org/wiki/Reaver_(Firefly)), and have the wall be protection for your citizens against them. But if you don't want to do that, here's another option. If your wasteland is literally a wasteland, without ravening armies or monsters, then there's nothing to keep out, and the only reason to have a wall would be to keep people in. Now you might think, why would people need to be kept in? Wouldn't it be obvious that they shouldn't go out into the glowing wasteland? But in practice, people are stupid. If there wasn't a properly secure wall around the city, you'd have: * Adolescents venturing outside on a dare to impress each other. Who cares that there's a rule against going into the wasteland and they could die - it's cool to break rules and take risks. * People who don't believe in the danger of the wasteland. Scientists and authority figures all say you could die if you go out, but that's just fake news - what are they really hiding out there that makes them so desperate to keep people inside? The second one of these could even be something to build a story around. Alternatively, the wall could actually be an unnecessary prison built by an authoritarian dictatorship to keep the people inside and under their control - that could also be something to build a story around. [Answer] Only with an incompetent enemy When the enemy were told to drop atomic bombs on the city they dutifully complied. However no one told anyone to turn the bombs on. So when they dropped they just made a thunk sound and crashed into the ground without detonating. So now your city is surrounded by a large number of highly radioactive objects that mostly kept themselves together (thus there is no dust to worry about, but maybe some small leaks in the casing). These are highly concentrated sources of radiation, so much radiation in fact that no one has been able to get near enough to them to move them away from the city. One option would be just dig a hole, bury the bomb, then surround them in a lot of concrete, but again no one can get close enough. So people put big lumps of concrete/lead around the city, concentrated near each bomb site to cut the radiation that is being directed towards the city. [Answer] You are exactly spot on Anti-radiation concrete is useless against material exchange between inside and outside. If the wall's radiation-absorbing properties are relevant, anybody going outside the city will need equivalent protection - probably more because they might get nearer to radiation sources. So if you need a 20-cm concrete wall, anybody venturing outside will need a protective suit. Typical walled city near radioactive site stories don't follow that. The suit would need to be the equivalent of 20 cm concrete if they plan to spend years of their lifetime outside. For occasional excursions, they'll still need breathing masks to protect them from inhaling radioactive dust. Unless, of course, it's okay if the bold explorers typically die of cancers - again, not typical for the usual stories. Walls don't protect from dust. Unless you make them so high that they prevent all air exchange, in which case a dome would be much easier to construct and maintain. Animals are even harder to keep out, rodents and insects will use any hole you leave. An airtight dome would be challenged to provide fresh air to inhabitants though; you'd need full climate control and air regeneration. Or some place from the outside that you can buy unpolluted air from, which would be an Achilles' heel for the city. The most relevant effect of a wall would indeed be for keeping out other humans, or possibly keeping in our humans. Depending on what kind of resources these humans have, fence & barbed wire might be enough or not. [Answer] Actually for sandstorms, but the median citizen thinks its about radiation. The old city was destroyed in the 5 hour war. Some of the suburbs survived and slowly rebuilt while the ecosystem collapsed around them. With all the new deserts about the new city gets sandstorms. A big wall lets the sand all pile up in one place. Then it gets "swept" away using diggers. Maybe the typical citizen thinks the sand is kept out because it is radioactive. But its really more about the inconvenience of sand piling up everywhere and hitting you in the face when the wind blows. Voters are scared of the sand's supposed radioactivity and frankly a giant wall is a better vote-winner than a public information campaign. (Besides, what would the campaign say? "Don't worry about the sand, since the fallout hit the water table our municipal water supply is 1000 times more radioactive"). [Answer] The wall is to keep people from wandering outside because some people will disregard the hazard. Also future technology can have an invisible wall on top of the visible wall like a forcefield so the wall is there to remind people of old technology. Even if the wall stops 1 person from going into the radioactive zone its worth it. No reference to fifth harmony. ]
[Question] [ The abovementioned fictional race aren't exactly merpeople from fantasy, but I call them like that just for the sake of convenience. Rather, they're semi-aquatic humanoids, who are really good at diving. This species still possess legs like humans, and they spend most of the time on their giant biological ships — which serve to the merfolk as mobile homes and fortresses. However, they almost never step on land (they don't even need to) except when raiding human coastal settlements and cities. These bioships are basically domesticated "kaiju", looking like a cross between a turtle, a whale and a dragon. Their average length vary within 300-400 feet, they can reach speeds of approximately 30 knots and dive to more than 1000 feet under the surface for a long time. Like tortoises, these bioships have large bulletproof carapaces under which there are large cavities filled with air — where the merfolk live most of the time. From there the "crew" controls their living ships by utilizing some kind of psychic link with the bioship's mind. There are dozens, if not hundreds of such kaijus, roaming the oceans. Many of the tribes consist of only one bioship, some unite in small fleets. But still most are divided and the tribes constantly fight between each other for resources, fishing territories, slaves and etc. When a bioship's crew encounters an enemy (be it a hostile kaiju or a regular ship built of wood or metal), the tribe sends a "cavalry" (warriors riding dolphin-like animals) to deal with the threat, while the home carrier tries to hide. The warriors, armed with various bladed weapons, are accompanied by a dozens or even hundreds of specially bred fish, designed for suicide attacks by exploding themselves with highly corrosive acids capable of eating steel some kind of biological explosives — picture crashfish from Subnautica, but much deadlier. While the riders distract hostile ship's protectors (if the enemy is an another merfolk tribe), the suicide fish try to get close to the enemy's ship and breach its hull/carapace, thus incapacitating ship. However, if the enemies appear to be stronger, the entire tribe simply flees the battle. For some reason, humans and merfolk didn't really encounter each other until this world's mankind reached 1940-1950s technology level. At this point merfolk started pillaging coastal towns and cities much more frequently. Naturally, the government couldn't ignore such a threat to its national security and began to dispatch military fleets for patrolling. However, because merfolk tribes do not possess any serious firepower, compared to conventional WW2 ships, they usually resort to hit-and-run tactics, fleeing away, once patrolling destroyers show up on the horizon. Alternatively, if the pillagers feel lucky, they might try to sneak upon the military ships in order to unleash acid fish on them. And here is the question. I am by no means an expert on the naval tactics and technologies, so I would like to ask you for advice. What would admirals likely do in this situation, if the goal is to provide security for the vulnerable regions? Is there some way to track kaiju-ships in the open ocean? Or maybe it's better to reinforce static defences at the coastal cities, rather than trying to find a needle in a haystack? Anyway, an expert opinion from you is much appreciated! P.S. One of the most likely strategies would probably involve hiring some tribes as mercenaries. Land humans have invented a lot of things that merfolk can't produce. Firearms, armor, medications, electronics, you name it. By bribing some of these pirates, humans can incite more infighting among warring tribes, thus reducing the threat to their cities to a more manageable level. [Answer] > > The warriors, armed with various bladed weapons, > > > ...are going to get absolutely wrecked by modern military firepower. Hell, they'd get wrecked by civilian firepower. > > are accompanied by a specially bred fish, designed for suicide attacks by exploding themselves with highly corrosive acids, capable of eating steel > > > Trying to promptly dissolve tough materials that are immersed in the ocean is not a very valid tactic. If you filled the boat with enough acid from the inside it would eventually go down, but you'd need to kill everyone on board first to stop them hosing it down and pumping it out whilst they sail for shore. > > Is there some way to track kaiju-ships in the open ocean? > > > [ASDIC](https://en.wikipedia.org/wiki/Sonar#ASDIC), which was the predecessor to SONAR, started development in 1916. This is a comparatively short-ranged system compared to the scale of an actual ocean, but without clarification is isn't obvious how much of the ocean would actually need to be surveilled... biology is complex, and you can't easily make something that can go shoplifting in San Juan in the morning and be back at the bottom of the [Puerto Rico trench](https://en.wikipedia.org/wiki/Puerto_Rico_Trench) for tea time... carbohydrates and lipids in cells have different responses to pressure, and a biochemistry that works under a few thousand metres of water ain't gonna work so well in the open air. Obviously, "kaiju" implies magic, but as you haven't defined or constrained it it is difficult to make any further suggestions as to what could be done. > > Or maybe it's better to reinforce static defences at the coastal cities, rather than trying to find a needle in a haystack? > > > Against knife-wielding surprise night-time raiders, WW2 era pillbox-and-machine-gun coastal defenses will be brutally effective. Against giant magical monsters... well, you haven't defined what they can do. Godzilla was magic and effectively indestructible. Things made of actual biology are going to suffer extremely badly from the effects of anti-tank weaponry on the surface, and and-submarine weaponry below it. > > What would admirals likely do in this situation, if the goal is to provide security for the vulnerable? > > > The army and marines and local militia would secure the shoreline, and any spear-waving primitive that tries to go up against them will be shot dead. Any kaiju detected coming in-shore are going to be hit by antisubmarine weaponry up to and possibly including tactical nuclear depth charges, and they are going to be liquified. So either your merpeeps have magical indestructible kaiju, in which case you get to decide what can be done against them, or they have regular biology and what they have to do is to make peace as soon as they can, before technology gets good enough to hunt them down in the open ocean and nuke them. > > an expert opinion from you is much appreciated! > > > Whilst it may be that there are some serious littoral warfare tacticians and strategists on stack exchange, I wouldn't hold up too much hope of getting their expertise here, especially against magical monsters ;-) > > Land humans have invented a lot of things that merfolk can't produce. Firearms, armor, medications, electronics, you name it > > > For an underwater civilisation, almost all those things will be as useful as a chocolate teapot. [Answer] ## They would probably be at an initial disadvantage, unless they had a submarine war like our world The dominant naval theory in our world was the Mahanian doctrine. This held that naval raiding couldn't win a war, and that decisive land bound ships were what mattered. At lower technology levels this is obviously true. Ships are very powerful, and did win many empires control of the seas. But, the 1940s to 1950s is where the inflection point happens, and submarines start to become more decisive weapons of war. Germany proved that in ww2, with their aggressive submarine warfare. These naval nations, if not well prepared, could lose a lot. You need advanced radar and sonar technology to detect submarines, and it takes a lot of experience and advancement to make it a reliable weapon. If the mermaid tribes realize the threat of humans they could launch massive assaults, using night attacks to launch dozens of pearl harbor scenarios. ## Humans would advance technology and use convoys more Radar and sonar technology would be a priority. If you improve them enough you can detect sea enemies. The enemy may have some skill with stealth, but humanity should be able to push past it with time. Convoys would be used for ships. If you have enough ships you can present an overwhelming threat. Harbours and coastal cities would try to fortify. You can't fortify every area though, so lots of use of people with binoculars and airplanes and fast moving ships would be used to defend coastlines. A lot of effort would be made to make secure communication lines so that you could launch quicker strikes. A lot of nations would fail. These efforts require trust and good tech maintenance and very rapid responses. Some nations lack enough trust to be that agile. ## The deep oceans would be hard to manage Enough planes and ships and you can watch a huge region, but the ocean is very huge. The mermaids could hide from radar and sonar with that much area. You need much more advanced technology to search the ocean in depth, and even today we're not quite there. Submarines are still able to hide with nuclear devices in the deep oceans. By the 2030s we'll probably be able to do it, with massive drone swarms, but we're not there yet. [Answer] # Submarines and aircraft carriers WWII brought many ways of warfare into the spotlight, changing how we fight. Submarines were plenty. Sonar might not be the best way to target other submersibles with much of the technology at that time but as the enemy has a floating/submersible city, targeting shouldn't be too difficult. Fire enough explosives under water, which are generally more powerful but with less reach and you can take those things down. Next is airplanes. With patrols you can have reconnaissance over huge areas. Bombers and fighters have good firepower, allowing them to absolutely wreck the enemy with little danger to themselves. With aircraft carriers and a complenent of boats capable of coastal bombardement they don't stand a chance. These two should already be enough to make the merfolk that are willing to attack humans extinct in short order, or force talks. They can have valuable resources or work power, which can be exploited in exchange for their lives/homes. Technology is scary and we fully exploited it during the second war. Repeating rifles, chemicals, devastating explosives at short and long range, timed fuses. Basically computerised warfare, rocketry and biological warfare are the only ones that still needed to be expanded. [Answer] > > What would admirals likely do in this situation, if the goal is to provide security for the vulnerable regions? > > > Naval officers, and indeed governments, would advocate the use of [convoys](https://en.wikipedia.org/wiki/Convoy) - grouping civilian ships together, escorted by long-endurance warships, such as destroyers with small artillery and [depth charges](https://en.wikipedia.org/wiki/Depth_charge). Considering your world is in the 1940-50s period, it's not unlikely to assume that your human navies might have weapons akind to the [Hedgehog](https://en.wikipedia.org/wiki/Hedgehog_(weapon)) or Squid mortars that would throw a number of deadly mortar rounds or depth charges, killing any fish-person unfortunate enough to be in range of these weapons. It was also mentioned that the dwellings (kaiju-ships) were tortoise-like in structure and design: > > ...Like tortoises, these bioships have large bulletproof carapaces under which there are large cavities filled with air... > > > Depth charges and Squids (the weapons mentioned, not the six-legged sea creature) would both be deadly to these cities for the reason that the shockwaves caused by these weapons would crack open the carapace [like eggs](https://www.youtube.com/watch?v=Gc7dCJfb2L8) (since they sound similar to submarines.) It should be noted however that these devices would only have a maximum range of around 250 meters. > > Is there some way to track kaiju-ships in the open ocean? > > > As has previously been mentioned by Starfish Prime, SONAR would be key to tracking these large moving masses throughout the seven seas. In addition to SONAR, [spotter planes](https://en.wikipedia.org/wiki/Maritime_patrol_aircraft) would be incredibly useful due to the fact that any large mass that isn't the same colour as the ocean is going to stick out like a sore thumb, making them easy pickings for aircraft with bombs, torpedos, or depth charges (smaller, but just as effective as ship-launched depth charges.) It should be noted that the kaiju-ships would only be able to be spotted by aircraft up to 100 feet, below this depth it would be quite difficult for aircraft to spot. > > Or maybe it's better to reinforce static defences at the coastal cities, rather than trying to find a needle in a haystack? > > > Should your fish-folk decide to attack seaside resorts or cities, rest assured that they would be given the same warm greeting that the Axis gave the Allies on D-Day especially on [Omaha Beach](https://en.wikipedia.org/wiki/Omaha_Beach) (but the attackers don't have guns to shoot back, so it would be a much easier time for the defending humans.) The fish people would be attacked by everything the humans would have at hand including: ## But wait there's more! Since you noted that: > > Alternatively, if the pillagers feel lucky, they might try to sneak upon the military ships in order to unleash acid fish on them. > > > Although this might be a novel idea (like as middle-age armies threw corpses into each other's castles in attempts to make each side ill), this would not work well. If the crew of a warship were under attack by a prospective fish-folk horde, they would need to either: (A) Change the PH of the water around the warship, such as by dumping limes and lemons overboard - something which isn't unlikely considering these fruit could also be eaten by the crew to prevent scurvy. Another thing that could be done is to (B) Electrifying the water around the ship, which would electricute the water, killing the fish and the attacking fish pillager people with the electric current in the water (the range would vary.) (C) In the event that there was no time to perform the above two actions, sailors and crew could easily arm and throw grenades into the water around their ship(s). What would this accomplish? Although the explosions would cause minimal harm, the shockwaves that ripple through the water would be more deadly, potentially deafening, pushing away or causing other horrible injuries (broken bones, etc.) to your fish-folk pillagers (in a similar way to the depth charges already mentioned.) [Answer] I think a more believable story for these mer-people not having much contact with 1940's and 50's America is that they had a treaty to stay out of each other's way and that trade would only happen through approved channels. All other contact was to be avoided, including having specific and approved shipping routes. Basically, we all knew about them and they knew about us, we just didn't mingle much. After WWII, these mer-people either have a leader that's been wanting to forcefully change this treaty, or a coop/change in regime that wants to attack. They are under the assumption that the ammunition and equipment is completely depleted, and that the troops are so weary they won't fight. They would see a nearly constant stream of troops going into and out of the battlefield, so they would assume it's similar "attack and flee" tactics as they use. What the mer-people don't understand is the pure manufacturing power WWII built up to be able to maintain weapons, ammunition, and other equipment nearly indefinitely. They also don't understand just how many people fought in WWII, which is [16 million](https://www.dday.org/2021/03/05/how-many-d-day-veterans-are-still-with-us/) or how any attack against the US would have initiated an immediate and extremely prejudiced attack. They also don't understand the fighting was fairly constant, rather than brief battles. Essentially, the mer-folk would have borne the brunt of the anger of an entire nation just returning from a war, now interrupted in their celebrations and desperate to continue celebrating and getting on with life. This would be a short and brutal war with few mer-people survivors. ## Weaponry You mention "bullet-proof" shells of these bio-ships. I hate to break it to you, but that's not a realistic term. It might be bullet resistant for small arms, but not when you get to anti-tank or even anti-plane and anti-vehicle weapons. We're talking about .50 caliber weapons (at the smallest) that can go through 1/2" steel plating and cement walls. Anti-aircraft weaponry, Going larger, you're talking about [artillery](https://en.wikipedia.org/wiki/Category:World_War_II_artillery_of_the_United_States), which even in WWII era is really big and powerful. The standard [howitzer](https://en.wikipedia.org/wiki/M101_howitzer) used shells 101mm to 105mm (roughly 4") in diameter and can penetrate hardened steel armor up to 7" thick or 18" of concrete. Your bio-shells might be able to handle a couple of those shots, but not many without significant structural damage. And then when we start talking about dive bombers with torpedoes, we start talking about attacking the appendages and head of the bioship. ## Submarine Americans had the [Seawolf class](https://military.wikia.org/wiki/Submarine_depth_ratings) submarine, which was supposed to be rated to 1600 ft, with a collapse depth of 2400 ft. Your bioships won't be able to avoid confrontation. The torpedoes these submarines used, the [Mark 14](https://en.wikipedia.org/wiki/Mark_14_torpedo) were able to hit a max speed of 46 knots (85 km/h). These used 643 lbs of [Torpex](https://en.wikipedia.org/wiki/Torpex), which would be the equivalent of nearly 1000 lbs of TNT. That's a much more powerful explosion in water, due to it being incompressible and the pressure wave would be [just as dangerous](https://en.wikipedia.org/wiki/Blast_fishing#Description) to a living being as fragments. ## Navy ships [Iowa class](https://www.navygeneralboard.com/the-fastest-warships-of-world-war-2/) US navy ships could hit 32 knots and ships from other countries could hit 45 knots. Your bioships aren't getting away from them, either. ## Explosive fish As another answer mentioned, these would have to be extremely powerful explosions and acid to do any significant damage to the equipment. Otherwise the acid would be washed off, the armored warships wouldn't even flinch, and nets would be erected around the decks to avoid the majority of it in the first place. ## Conclusion The mer-folk get obliterated in an extremely one-sided fight that ends up with them nearly exterminated and have extreme sanctions set up to prevent them from trying anything like that again. Their whereabouts would be highly tracked, the oceans would be continually heavily patrolled, and their way of life would likely end in a few decades due to the continual technological advancements on land they wouldn't have access to. Their younger generations would leave the bioships to join the land dwellers, even at the expense being subjugated and oppressed like the other minorities of the 60's and 70's civil rights movements would try to prevent. In fact, the mer-folk would be another factor in the civil rights movements, adding to the pressure to repeal [Jim Crow](https://www.history.com/topics/early-20th-century-us/jim-crow-laws) style laws and bring about more fair equality. Unfortunately, they would end up being a major focus of the opposition and suffer many casualties. But now I'm getting off topic. Eventually, the mer-people would be accepted back into the international scene, but with the same sort of suspicion as any other country that's attacked the US in the last 100 years. They would hesitantly accept technology, but still be considered a 3rd world country, due to not producing any of it themselves. They wouldn't be impoverished/underfed/poor, but they also wouldn't be rich, unless they took over the majority of commercial fishing. If they were to do this, they would also be massively powerful and outspoken custodians of marine life and be working hard to reverse climate change on the international scene. But again, I'm getting off topic. [Answer] You know, everyone here thinks so hard about depth charges, torpedoes, naval artillery and other actual weapons, that they forget, that some military vessels of that time got the ultimate anti-merfolk weapon with them: The active Sonar Well, yes, you could use Sonar for tracking submarines and other big things below water. But there is one thing few people take in consideration about sonar: [Sonar is loud](https://www.scientificamerican.com/article/does-military-sonar-kill/#:%7E:text=Sonar%20systems%E2%80%94first%20developed%20by,top%20out%20at%20only%20130.) So what could your WWII-era surface humans do? Give me a ping, Vasili. One ping only, please (hunt for red October) -insert screams of merefolk here- EDiT: You know, this could be your Plot Hook to make a first contact between merfolg and surface humans... up to that point in history, Sonar was supposed to make the Titanic no happening again, but suddenly there were pings in all oceans... [Answer] Considering our WW2, there are potentially four areas of naval warfare to look at: * Battleships * Submarines * Landing craft and transports * Air power and carriers Battleships were famously discovered to be obsolete early on in WW2, because they are very costly and are very vulnerable to both subs and bomber planes. Some even claim that Pearl Harbor ultimately helped the US by accelerating their transition away from a battleship-heavy navy. But if WW2 hadn't happened, presumably navies would continue to stay invested in battleships into the 40s and even 50s. So you have room for quite a few epic and bloody battles, up until the point where most of the battleships get sunk and the humans decide to try something different. Submarines around this time would not work very well, I think. WW2 subs did not have much endurance, agility and couldn't dive well. The dolphin cavalry would easily locate the sub and kill it. Possibly the sub could get close enough to torpedo the bioship - but it would be a suicide attack. Later (nuclear) subs, like the Seawolf class, might have a chance if the merfolk cannot dive very deep, but otherwise are also quite vulnerable. Passive ships, like freighters, transports and landing craft would be effectively curbed by the merfolk. The way you've designed it, they are perfect raiders. Presumably the bioships have infinite endurance, they can linger on sea lanes indefinitely, strike and flee. Invasions would also become difficult. Perhaps there's not much merfolk land to invade, but if it's a three way with two human nations, the merfolk could be a very powerful kingmaker between them. The geography of your world comes into play as well. Countries on large landmasses, such as Russia, can easily move their industry inland and channel logistics into trains and planes. The merfolk will have little to do besides maybe sinking some fishermen and drive up sushi prices. But for island nations and archipelagos like Japan or Oceania, the merfolk can easily be an existential threat. Of course I've saved the most interesting part for last: The way you've written this, your merfolk have no air defence whatsoever. They would be absolutely crushed by air attacks. Long range planes taking off from land bases (with no enemy planes to worry about, the bombers can be optimized for range at the cost of maneuverability), or carrier borne squadrons, will fly in, bomb the kaiju to hell, then the fighter pilots will get some live target practice with their machine guns and cannons - talk about shooting fish in a barrel. If the merfolk try to dive, no problem - the bombers can drop depth charges. Survey planes can keep flying patrols and spot the enormous bioships easily on flat blue ocean. Underwater bioships at shallow or medium depth water can be spotted, same as anti-submarine aircraft do for subs. Planes can be equipped with radar or IR cameras. They can drop sonar buoys. The navy can build fake, "decoy" freighters to lure the raiding parties, and then kill them with the planes. In our world, WW2 saw the advent of atomic bombs. During WW2 these were used on land, but after WW2 they were tested in the ocean, which was eventually stopped out of concern for the well-being of the fish and what not... Well, here you have the opposite problem. Yet another element of WW2 was an interest in biological weapons. If your opponent is completely biological, developing some kind of contagious disease or poison seems like a very effective strategy. For example, engineering a virus that targets the bioships, or spraying the oceans with a poison from cargo planes, could be devastating to the merfolk. Worse, there would be fewer complaints about human rights violations, since they, well, aren't human. And also not covered by the Geneva convention? Uh-oh... At some point you also mention 1950s. In our world, late 50s were a distinctly post-WW2 period, with nuclear submarines and carriers coming on the scene, as well as jets and very advanced electronics/sensors. A WW2 navy might obliterate these merfolk but it would at least break a sweat. If we're talking about something like the late 50s US navy fighting these guys, I think it devolves into something that is part funny, part sad. The environmentalist hippy anti-war protestors back home would be a bigger fight than the merfolk. [Answer] I think a WW2 navy would deal with these fish people with depth charges, torpedoes, and all the good anti-submarine weaponry you would expect. If we are taking the side of team humanity, the merfolk couldn't stand a chance, they would be forced into hiding. The coastal nations would reinforce their coastal towns and cities with normandy-level defenses, any fish people coming up onto land would be absolutely laid out. Although I have a few ideas for how the merfolk could fight back. I know it isn't technically answering the question, I think that has been done quite a bit here, but it might be good to develop these merfolk to be a legitimate threat instead of an annoyance for us. So, the Kaiju. They could probably fight submarines. Seeing as they're huge, they're probably quite strong. If they could get within striking range they may be able to break submarines. From there, either the merfolk could storm the sinking submarine, slaughtering the crewmen, or just leave the sub be. Its fate is sealed, with damage of a giant sea creature fist right in its middle. As for how to get close, I think the best bet would be to wait at the sea floor if its at an approachable depth. Like near ports where they would have to dock perhaps... It would probably be impossible to differentiate it from the seafloor, according to my amateur's level knowledge of sonar in the 40s. That or they charge the submarine if they know that its alone. No risk of enemy reinforcement. At this time, subs aren't fast enough to outrun them, and if the kaiju had a good enough sonar ability, they could probably detect an approaching torpedo and evade. Although with a very close torpedo shot, they may be too big to avoid it. but once they get close enough its back to punching. As for the suicide fish, yeah they cant do anything to the hull, but if there is enough of them, and their blasts strong enough, they may be able to damage more delicate components. They could damage propellers or rudders, or swim upwards to jump out of the water and on to the the deck, anything close enough to the water, maybe deck machine gun mounts, or depth charge throwers, could be damaged. so like this, they wouldnt be incapable of damage, but it would still be quite an uphill battle. ]
[Question] [ In a science-fiction story that I am writing, there is a species of bears that only live in a specific oceanic island. They are the descendants of American black bears (Ursus americanus). They are my trolls. The oceanic island where my bears live is smaller than Ireland, but bigger than Réunion, precisely, close to Hawai'i's size. The island has a subtropical humid climate (like New York City, New York, United States of America). The highest point of the island is 1,397 meters (or 4,583 feet if you want) (the same as Mont Pelée, Martinique, Fifth French Republic). There are six environs: three forests, a mountain, and two rolling hillsides. There are many plants and the non-marine animals are mostly insects with some bats, birds (some large, some small, some medium, some flightless, some flying, some semi-flying), and rodents (also, some large, some small, some medium). If I want to go on a realistic way, would they go through insular dwarfism (like the Flores human) or insular gigantism (like the dodo)? [Answer] Your island will produce Lava Bears. <https://en.wikipedia.org/wiki/Lava_bear> [![lava bear](https://i.stack.imgur.com/tIvUt.jpg)](https://i.stack.imgur.com/tIvUt.jpg) > > The lava bear (also known as sand lapper, dwarf grizzly, and North > American sun bear) is a variety of American black bear (Ursus > americanus) found in the lava beds of south central Oregon. The animal > was described as a very small bear with wooly light brown fur. The few > lava bears that were killed or captured were a little larger than a > badger. It was once thought to be a separate species. However, > scientists who examined the specimens determined that the animals were > stunted due to the harsh environment in which they lived > > > I here assert that the harsh, resource poor characteristics of your island will produce small, stunted, badgerlike bears. They will be more arboreal than typical black bears, climbing like bear cubs their entire lives. Go Lava Bears! --- @T.E.D. asked me to wax philosophical on island dwarfism. Here goes. Islands are just one type of reproductive isolation (but an efficient one) and a reproductively isolated species can stay the same size or get bigger or smaller. I assert larger bodies are useful in the context of lots of resources when the large size allows the organism to capitalize on these resources more efficiently than normal sized individuals of its species. Because there are lots of resources, this is not limiting on body size. Example: Kodiak bear can use seasonally available marine mammals and store resources in its body better (polar bear style). Komodo dragon can take large ungulate prey animals better (tiger style). Dodo birds can eat more seasonally available fruit and store the resources in their large body (turkey style). If the isolated population is in a resource limited environment, smaller bodies are calorically cheaper to maintain and might allow use of resources that for the species generally are used only by juveniles or used by smaller species. Examples are Sahara crocodiles (eating bugs), pygmy hippos in the resource poor rainforest, lava bears living like raccoons in a desert equivalent. I do not know if the OP wanted the islands in question to be resource poor or not, but I asserted they were because I want lava bears. [Answer] They'd be small, due to [Island Dwarfism](https://en.wikipedia.org/wiki/Insular_dwarfism). The thing that controls whether you get dwarfism or gigantism is what was the limiting factor for the mainland species. Dodo get big because the main limit on small flightless birds is usually predation. for large herbivores and large carnivores the limit is getting enough food so you get dwarfism. Black bears are predators so dwarfism is possible, assuming the food is not abundant. But if there are large rodents and ground birds food is abundant, and black bears are omnivores so I would not expect a huge change. Homo floresiensis may give a false impression, as hominids have a very high caloric demand, even then they only reduced to the same size as ancestral Australopithecine. So expect dwarf bears but nothing that drastic, probably something between Himalayan black bears and sun bears. Prey size is a factor, since we don't know how big the prey is we can't give a firm number, but as predators expect to get no smaller than twice the size of the largest prey item. [Answer] As a matter of fact, something quite close to what you want actually exists: the Kodiak bear, which lives on Kodiak Island (Alaska) and adjacent islands. Although it's a subspecies of the brown/grizzly bear (Ursus arctos) rather than the black bear, they're not all that much different. They tend to be larger than their mainland relatives. (Also note that bears are generally good swimmers, so you'd want your island somewhat isolated. <https://en.wikipedia.org/wiki/Kodiak_bear> [Answer] [The island rule, also known as Foster's rule](https://en.wikipedia.org/wiki/Foster%27s_rule): they will be smaller. Islands tend to make small animals larger (the dodo was a kind of pigeon) and large animals smaller (the pygmy mammoth lived on an island). Bears are large. They will shrink. [Answer] Your bears will be either small or extinct. The [territory size](http://westernwildlife.org/black-bear-outreach-project/biology-behavior-3/) of a female black bear is 2.5 to 10 square miles and females do not overlap territories with each other. The size of Hawai'i is ~11000 square miles. By math, your island will support no more than 1100 to 4400 brown bears currently--assuming most of the terrain is able to support bears. A population size of less than 2500 adults is considered "[endangered](https://www.britannica.com/story/what-makes-a-species-endangered)" by the IUCN. So your bears need to require less resources per bear in order to achieve a safer population level, hence they need to be smaller. [Answer] I feel like you are describing the bears of Haida Gwaii? <https://en.wikipedia.org/wiki/Ursus_americanus_carlottae> [Answer] When a question is scrutinized too intently the obvious can become elusive. The particular attributes of the individual animals in an isolated population that successfully reproduce determines which attributes are available in subsequent generations. Mere millenia aren't enough to expect mutations to give rise to a significant number of new attributes. That implies that the bears on your island will be gradually reducing the diversity of their genome. Individuals express a subset of their genes in response to their environment. Unused potential isn't lost instantly, or even rapidly, except when its presence reduces reproductive success. Expect the bears characteristics to remain within the available diversity they arrive with. The answer to the question "do I get giant cave bears or pygmies after 1000 generations?" depends on what effect the size of an individual has on its reproductive success. Its more common for the pressures on an island to favor smaller individuals, but giants like the Irish Elk and the Kodiak Bear result from environmental pressure favoring larger individuals. In the hypothetical case, the environment is a benign climate with a predictably limited diversity of food sources and habitats. A large highly adaptable omnivore like a bear is likely to be so successful competing for food and habitat that the ecosystem collapses and the bears die off in a relatively brief time scale. An island ecosystem is fragile. The habitats and species these bears share the island with would be more likely to remain in balance if some sort of an unusual circumstance forced the bears to compete with each other for an exogynous food source rather than exclusively with the other inhabitants for indigenous resources. For example, Kodiak bears compete with each other for fishing spots for the salmon run that is a huge fraction of their annual caloric intake. Its safe to assume that anything indigenous that a bear that didn't fish successfully could eat instead is likely to be eaten. The argument that a certain population size is needed to ensure adequate genetic diversity is unavailing. Its an anthropic argument, i.e. that some population must be adequate for a species to survive/fail because the species isn't/is extinct. It only works a-posteriori, i.e. after the fact. There were an enormous number of passenger pigeons just a few decades before the last one died in a cage in a zoo. Tens of millions of individuals. That there wasn't anything in their genetic pool that would let them survive the loss of the continuous swath of old growth forests was self-evident after it happened, not before. Environmental pressures determine which individuals survive to be able to reproduce, and mating preferences tend to favor healthy individuals. If being smaller makes an individual more likely to survive and be healthy, larger is less likely to be available in later generations and vice-versa. How many individuals are needed to ensure sufficient genetic diversity for a species to survive some hypothetical environmental upset in the future has no role in the process. The genetic availability of un-expressed traits has no role in the process. ]
[Question] [ The setting is based on the Earth during the 60's, but with two big changes: * Magic exists (although somewhat limited to humanity). * And so do all sorts of magical creatures (Dragons, dryads, ghouls, faeries, etc). In this setting, the humans have long been using the approach of keeping their distance, and because of that a pretty big portion of the world is virtually unexplored. But how do I explain that situation? How do I go about explaining the continued existence (and even dominance) of some of the more dangerous creatures, when humans have access to the same level of technology (and weaponry) as we had in the 60's? Why wouldn't the humans just go out and do what we have been doing to our wildlife in the past few centuries? This info should be taken into account: * While the technology and the environment are similar, the history of this world is very different from ours. * Magic has both its own limitations and those imposed by religions. Even in this modernish setting a lot of people are afraid of it. * Having the magical aspect of the world hidden to most of the population (like the Muggles in Harry Potter) is a no-no. Everyone can see the world just as it is. * There are a few sapient races in the world alongside humans, but they mostly keep out of each other's business and shouldn't be taken into account for this issue. [Answer] We haven't exterminated all the lions and tigers yet, even though we could. By the time we're strong enough to wipe out a species, we're able to question whether we should. The answer should probably be unique for each monstrous species that hasn't been accidentally wiped out. Dragons are bulletproof. Trolls have regenerative powers. Dryads make the soil more fertile just by existing; kill them and you'll soon find yourself in a desert. Ghouls are good at hiding; they don't even show up on infrared. Faeries are (perhaps wrongly) thought to be beautiful and lucky. Wyverns are conserved solely so hunters can hunt them. Griffins are symbols of national pride. Manticores have been wiped out in all civilised regions, but are able to survive on the outskirts of countries with weak and unstable governments. Leprechauns will bribe you with a gold coin if you let them go. Unicorns are a tourist attraction... [Answer] Spontaneous generation. Sure, some magical creatures can reproduce by the usual biological means. But magical creatures are, well, magical. They are generated by magic, which is a fundamental feature of the world, and as such are not subject to normal evolution, or extinction. If people show up in a new place and wipe out all the dragons... thy just pop up again a few years later. You can clear an area of dragons (or whatever) temporarily, but the only way to clear an area permanently is to somehow make the spontaneous generation of new magical creatures impossible, which requires sufficiently extreme measures as to make the area unsuitable for human habitation as well. [Answer] # MAD ends Expansion-By-Colony too soon Tanks and air support brought about a huge revolution in the ability to devastate areas. Without planes, exfoliating an area with Agent Orange is much more difficult. With no tanks, you're going to have trouble against (say) armies of magical beasts the size of elephants. So colonizing most of the world didn't really become possible until very modern technology was invented. The big nasties are too big, and too nasty. But the firepower that can take them on with relative ease, also brings nukes along for the ride. Say using magic makes it easier to refine the uranium and manufacture the warheads, so they're obtained earlier. No superpowers wants any of the others improving their position dramatically by claiming huge swathes of what's considered The Wasteland. Fortunately(?) none of them can build up a big enough military to be able to credibly defend the homeland, and field the large armies required to tame large sections of the shadowy corners of the earth. In the face of MAD, none of them dare make such an aggressive and provocative move. They'll be limited to slowly extending their reach over time. [Answer] Something to think about here. It took 70 years from scientists officially recognizing the giant panda as a species before we managed to capture a live one. Large parts of the world are still very hard for humans to thoroughly explore and catalog, even outside of how little we know about the ocean. Yeah, most of Europe is explored and we're pretty sure barring actual magic IRL that things like wolpertingers, tatzelwurms, and wyverns don't exist. Similar for most of the US and large parts of Japan and China. The thing is though, Earth is huge, and human population is actually rather concentrated. A vast majority of the surface of the earth is not being observed by humans at all at any given point in time. Every continent and a vast majority of countries have some region that is mostly uninhabited on a regular basis, often a rather large one, and quite often we don't even have good satellite coverage in modern times either. Stories of yetis in the Himalayas may not be very likely to be true, but if they are it's not all that astonishing that we haven't actually found any if they're even remotely intelligent since most of the mountain range is unobserved most of the time. There are similarly huge swaths of the Amazon that haven't been touched by 'modern' man, and even some parts of Africa that are insanely difficult to get to even in modern times. The other thing to think about is that humans are remarkably good at not acknowledging things that don't fit their world view. This was a huge issue during times of European colonial expansion, when it was quite often assumed that the natives, despite having lived there for their entire lives, could not be relied upon to list what animals lived in an area. That mentality is why it took so long for the okapi, pygmy hippopotamus, saola, and many many other animals to be 'discovered' by western science. Together, I'd argue that these facts mean it's pretty likely that humans wouldn't even know some of these creatures exist even if we had expanded to cover the whole world. --- However, let's ignore all that for a moment, because I think you're losing out on a very easy solution if you remove one of your restrictions. If we actually factor in those other sapient races and assume that they have much better access to magic than humans together with more ecologically minded outlooks, everything kind of solves itself. Because humans have limited magical ability, any race that has significantly better magical ability than us is likely to wipe the floor with us in any war up until about WWII era technology is developed (and that assumes the other race doesn't develop technologically as fast or faster than us). The thing is, we would eventually try to expand enough that they would push back, hard, no matter how hands-off and isolationist they are, because they want to keep their own territory, and at that point we'll likely just stop expanding because we quite simply can't beat them. That means, at least until humans get tech that can out-match their magic (and even modern tech is just barely to the point that it could reliably deal with a platoon of level 10 wizards from D&D), large parts of the planet are effectively off limits to humans. [Answer] The remaining Magical creatures are good at hiding Cats are excellent creatures widespread on the real Earth, because they hide from big things that eat cats, and hide while stalking prey. The same thing could apply to magical creatures - stay out of sight intelligently. Another option is to stay out of sight by living where humans cannot go, and intelligently avoiding contact. Deep-sea creatures and tunneling creatures could live this way. A wackier idea is creatures that live in the Earth's mantle, far away from human senses and instruments. "Not My Problem Field" as described in Hitch-hiker's Guide to the Galaxy is another method. A psychic field that makes people uninterested. It doesn't make its wearer invisible or smell-free or anything else, it merely makes other people just let the wearer continue on whatever they're doing without even remembering. Several other varieties are present in Peter Watts' novels. Internet worms... Software "wildlife" that lives on the order of nanoseconds, reproducing and abandoning its current frame of life far faster than humans can notice. And when humans do notice them through usage of resources and send automated hunter-killers, the hunter-killers become part of the wildlife. Things that move and live between humans' ability to notice them. Literally only moving between your eyeblinks, as the most obvious example. Things that are too small to notice... microbes and life made of quarks. Things that are too big to notice... a turtle the size of Asia. Something similar is in the Dead Space games. [Answer] I personally would suggest something along these lines. * Have the ability for monsters and magic to be able to subsist be dependent on another factor. IE: have Laylines and the area around them be the only places that monsters roam and magic is usable * Have electricity, chemical reactions, and physics be somewhat altered in the presence of magic. Which would explain restrictions to technology's growth, but still make it possible to coexist with magic. Society-wise, have it so the common people see the Monsters as uncontrollable Natural Disasters. And most people see Magicians as either "like the military" but more dubious, or as people with dangerous maintenance jobs (for both the tools they use and the work-sites they are active in). It would basically put a big barrier in the way for either side to greatly influence the other, but they would still be a danger to the other side, giving some tension - if for instance one of the other races could only live in the presence of magic. [Answer] Faeries and dryads tend to be elusive by nature, so their magical abilities are a quick handwave. I imagine ghouls would want to avoid living things that fight back. Dragons are either huge predators that have a huge hunting territory and avoid noisy machinery or hibernate for extended periods after gorging; maybe both. As for magic in general, maybe interest and practice have surged and receded throughout history (you did mention religious influence). This would explain practices being lost in archives or the burning of Alexandria, for example. So, magic could always be in a struggle for rediscovery and comprehension. Though, I suppose that means the leading experts would either be descendants of ancient tradition or historians. Cue adventures with Indiana Jones, Mage Extraordinaire! If magic is underdeveloped compared to technology, perhaps magic (or enchanted) weapons are the only really effective way to harm some of the magic critters? Some Fae legends have them vulnerable to iron, so maybe there's a certain mystical forging method? If people don't have effective weapons and can only scare off the critters, that would be the stand-offish situation you had described, yes? [Answer] Expansion could be limited due to ecological balance issues. If you expand too much and with great effort reduce the dragon population, then the gargoyle population gets out of control and ventures into the cities, and they are quite indestructible, heavy, destructive and deadly. Their skin is even harder than a dragon's scales. The gargoyle's only predators are dragons, and even they can only pop them with solid minutes of dragonfire, much like a microwave pops popcorn. If you see a dragon in the distance just hovering near a mountain slowly moving and blasting the side of the mountain for minutes, you can know it's trying to pop a gargoyle that is running for its life. When you see the dragon is no longer moving and it's just hovering in place still blasting the side of the mountain, you know that the gargoyle is done for, it didn't reach a cave in time, and you can expect a distant pop. That pop signals a feast for the dragon. Dragons are picky eaters, they don't eat anything raw, and gargoyles are one of the few creatures their fire can cook without turning it immediately to ash. Dragons don't hunt most other creatures unless angered. Dragons are quite territorial and dislike change, so you can't really expand without wiping them off, and if you do, then you have to deal with the resulting gargoyle problem. Popping even just a single gargoyle is a tremendous feat for humans, the fire brigade can blast them with both magical and non-magical fire at same time, but we are no dragons, so it takes longer and the resulting explosion is often deadly even when the fire brigade is equipped with magical heavy-duty shields. Also, they really don't like fire, so keeping fire on them for minutes while they go on a rampage is quite a suicide mission, but we have no better way to kill them. Also we cannot contain them, they can burrow through metal, it's insane, their physical strength is unmatched. Previous expansion attempts have resulted in many direct and indirect casualties, and pushing for expansion is political suicide nowadays. Many people have lost relatives due to expansion attempts, so now we strive for balance, extreme expansionism is a serious offence. Social policies have been implemented to keep the population under control. Land and resources are scarce, many people are unhappy with this state of affairs, but there is no known better way yet. Some other somewhat civilised creatures manage to live in harmony with the territorial dragons by not disturbing the environment too much. Elves for example live in the trees without disturbing the environment, and dragons seem to leave them mostly alone. But humans are not so good at leaving the environment as is. Even just making a dirt road in a dragon's territory can anger it. If a dragons notices an artificial change, they are known to hover near it for days waiting for the perpetrators to show up again. Expeditions are extremely dangerous. Planes can't make it past the great mountain ring unless they fight off dragons. We don't know much about what's outside the ring. We could have satellite imagery of the whole planet, the technology is there, but funding for such research is non-existent as it's considered expansionist. It's a shame. [Answer] You don't detail the magic in your world, despite it being the obvious answer. If stopping bullets is a tier 1 spell, every predator with that spell is a huge danger for a modern army - with the dominance of firearms on the battlefield, armour and shields fell out of fashion. If a dragon can absorb heat, fire and other energy, you can't even nuke it. All you need is the appropriate magic - and depth. Until 18-something, the interior of both South American and Africa was largely unmapped. Add some flying danger to prevent airplanes travelling there and you are set in the 60s - right where satellite mapping of the Earth was a new thing. The main reason we have exterminated everything else is that we took away their chance of fighting back. A tiger will still kill you if it gets close, but you can kill it today at a distance where all it sees of you is a blurry splotch (<https://www.businessinsider.de/pictures-of-how-cats-see-the-world-2013-10?r=US&IR=T>). If the magic in your world eliminates this advantage, humans suddenly are naked monkeys without claws and with ricidulously useless teeth again. [Answer] ## Magical Conservation Having your human's tech be equivalent to the 60s is actually a really interesting setup. At that point humanity had enough knowledge about the natural sciences to understand things like biodiversity and ecology, so your society should have the same kind of understandings. It was also a prime time for the development of new medicines using synthetic chemicals. Combined together and you have the perfect explanation for why your magical humans would keep nasty beasties around. Firstly, as others have pointed out, just because we have the ability to destroy dangerous animals doesn't mean that we automatically strive to do so. In fact it often backfires in unexpected ways when people wipe out a predator from a region. Killing too many wolves means that the deer population explodes, which then leads to a sudden decrease in the plant life in that area. Now imagine that same scenario, except with magical creatures. Humans wipe out the local wyvern population, but those were the only things keeping the gryphons in check, and next thing you know you can't walk a mile down the road without having to dodge a flying lion that thinks you look tasty. Sure, your humans could start killing the gryphons as well, but that just shifts the problem to a new species having a population boom and all the issues that will cause. It is easier all around to just avoid the wyverns and let nature handle itself. ## Age of the Alchemist Related to the conservation issue above is the fact that humans are really good at finding beneficial chemicals in nature and then synthesizing them. By the 60s we were producing antibiotics and painkillers that were originally based on natural remedies. Assuming that your world includes magical plants as well as animals, and there would be a very large incentive for the burgeoning alchemical industry to push for conserving as much of nature as possible (at least until they have had a chance to study and exploit it...). You don't even need to be worried about magical animals in this case. My first example with the wolves and deer is suddenly a lot more important when those deer are eating all of the herbs that are used to make Healing Potions, and not just normal grass. Once people notice the knock-on effects of over-hunting animals there is going to be a much bigger push to keep the natural balance. And all of that is ignoring the very real possibility of magical creatures being the source of rare chemicals/ingredients themselves. If you kill all of the dragons, then where are you going to get dragonscales or dragonblood from? And without that how are you going to make Amazing Thing X? At the end of the day, people are going to be more than willing to risk a little danger for a large perceived reward. The world might be safer without dragons or gryphons or dire rats, but if keeping those things around provides a bigger benefit then someone is going to push for it. Usually whoever stands to gain the most and lose the least from that scenario. Having 60s era governments and pharma corporations be greedy enough to prevent the extinction of dangerous animals just to keep making money off of them is pretty believable, to me. [Answer] They've learned to live with it by the time they get around to being able to exterminate them? Outside of the western world there's plenty of dangerous animals that roam around. Just take a trip to Africa and see how friendly the local wildlife is. Even the hippo's that people find adorable are some of the most murderous creatures on that part of the continent. Now imagine that you have magical creatures far more dangerous. A dragon can probably take an elephant gun in stride, and other creatures are simply too numerous or tough to go after as well. So by the time you've developed the infrastructure and technology to really start hunting them you've basically already build your society around them. "Here be dragons", you feed it some livestock sometimes or perhaps try to tame or co-exist with it, but are you really going to get some military grade armored vehicles with autocannons or full canons to try and take some out? You might not even be able to target it properly with 60's technology so you'll be exposed in a turret with a limited traverse rate and you could get eaten before you ever get an angle on the beast, assuming it's just one... And that's the crux. You might have to approach them as you would approach a fullscale war. You shot Bob the Lovecraftian horror? Well his cousin Kevin is going to see why he hasn't received a tentacle this last month and then the ball gets rolling as he sees Bob slumped over half a dozen armored vehicles while humans are still trying to clean up the mess. They are magical creatures, horrors and pests. Many of them will likely form ecosystems where the troublesome pests that fairies are will take up shelter near bigger and nastier creatures. Try and shoot that small family of Dragons out of the sky while a swarm of fairies is causing mischief around your armored vehicle and Bob is slithering by to see what the fuss is all about. Better let it be. Or nuke em from orbit, only way to be sure. [Answer] What if the religions are really politically powerful and they have managed to create some kind of protectorate for the animals. Maybe there's something that they need the magical animals for that they're unwilling to share with the rest of the populace. They might have purposely created this atmosphere of suspicion and fear around magic as an extra check against the protectorate being challenged and the source of [whatever it is they need the magical animals for] being challenged. - Maybe they use the animals somehow to limit the amount of personal magic that people have available to them. Perhaps they deliberately discourage too much interaction with the other races as well because the other races have a bit more understanding of this alternative ecology you've got going. [Answer] ## The creatures are simply too powerful, and don't like visitors Perhaps the deeper you go into magical territory, the stronger the creatures are. Even with planes, tanks, etc., humans have learned that whatever aggression they provoke the (normally peaceful) creatures with, they get a retaliation proportional to the original attack. They dare not use something like a nuke (or maybe they did only once), because the most powerful creatures are capable of an equivalent response (kind of the reason why there's no WW3 up til now, there's just too many nuclear powers). ## Politics, human/creature rights, autonomy Your question could be asked the same of real-world places like North Korea. There is a credible threat, their leader even boasts about it, yet the UN hasn't destroyed the government/country yet. War is often the very very last resort after all other attempts have failed. ## Religion The quickest way to go against pure logic is by involving faith/religion. Make the creatures special. ## Farming/mutual benefit If the creatures (alive) can give us a benefit, then there is strong motivation for us to not wipe them out. Perhaps they can offer material or services that are unique to these creatures. [Answer] Not all the land is valuable. If the cost-benefit of organizing an army to eradicate monsters from a desert, or a swamp, or some glacial islands is negative, nobody would do it. The only reason why an eradication of monsters from a far and worthless land would make sense would be to protect the nearby lands from attacks from rampaging monsters... but if the monsters stay quiet in their lands, they would remain relatively safe (except for some wannabe safari-hunters, but hunting a dragon would require so much assets and organization that only very few could afford it, so it could never become so common to threaten the existence of the dragon species) If in the civilized side of your world there are 2-3 main superpowers and the monster-inhabited lands are too far from their main land to be efficiently exploited, probably they would prefer to keep the status quo, by nominally claiming parts of these lands, but without colonizing them. Maybe they could sign a Treaty to keep these lands as a kind of scientific sanctuary. Think the equivalent of USA and USSR with Antarctica: I don't think they would have agreed to sign the Antarctica Treaties and keep it as a scientific reserve if it were near to their mainlands and/or they thought they could easily exploit it. ]
[Question] [ I'm thinking about a species that is at the intelligence level of proto-humans. They have limited language but can still discuss concrete things with a little bit of abstraction. For instance, their language has non-locality (they can talk about things that are not right in front of them) but not abstractions like "beauty". I'd like them to not be able to comprehend numbers, but I think that's wrong. If I'm not mistaken, some non-human species have at least some concept of number. I'm thinking something like this: they are able to recognize one and communicate about a single thing as a single thing (there is a single rabbit at the river). They are able to understand groups, and perhaps have some words for small groups that they can readily subconsciously count. So perhaps they have a word for "pair" and "few" (for 3) but can't group anything above 3 into anything other than "group" - "there is a group of rabbits" might mean anything from four to a million. The problem I'm having is how to relay this convincingly. With words for pair and few it is clear that they can distinguish some number of things. Why wouldn't they be able to distinguish more? What is preventing them from creating a simple counting system, and what consequences would that have on their ability to communicate? [Answer] Four is a good limit. Most even semi-sentient things should understand something sliced twice is "quartered" into four, for example. If you read any paragraph of well-written text, you are very unlikely to find one which has a specific number larger than four, other than in threads like this where numbers are being explicitly described. In normal speech, we use numbers very rarely. We give far vaguer terms, instead. This is unlikely to be an issue for you. Consider comparing opposing forces: * There's just a family of them, we can take them. * There are rather a lot of them, this might be risky. * There are more of them than us, but we might hold if we dig in. * There are a lot more of them than us, they'll overrun us. * The plains are crawling with them, we must run now! Many of our collective terms have a built-in size limits which are approximate, non-numeric, but very well-understood by everyone who uses them. People are grouped as self, family, clan, tribe, nation, race. Property as desk, room, household, street/block, village, town, county, country, continent, planet, solar system, galaxy, universe. A pod of dolphins is up to a few dozen individuals; above that it's a group, then a supergroup for when it's up in the hundreds. Same with distance: a thumb, foot, pace, walk, long walk. Money: a farthing, ha'penny, penny, tuppence, shilling, quarter, pound... Time goes in moments, heartbeats, breaths, morning/dawn/afternoon/evening/dusk/night (do we have a name for these day-parts?), \day/yesterday/tomorrow, moon, season, year, reign, epoch. You don't need dates like "1986", you just need "towards the end of the glam-rock era", "a few years before millennials started being born". Containers and ingredient quantities are a pinch, thimble, teaspoon, tablespoon, cup, fist-sized, head-sized, crate,... you never need to measure an ingredient as "a head-sized lump plus two pinches", you're good so long as you're within 20-50%. So as long as your measures are within a couple of sizes of each other, you can make it work just by using them. Which is basically how cooking in America works, in fact, with tsp, tbsp, floz, cup, pint, quart, gallon... replace those with "apple sized" and such, and you've got something which works for any society. Even generic terms, like a couple, few, several, lots, plethora, lots'n'lots, a shitload, countless, overwhelming* ...have comparable (if overlapping) sizes. Before you knew what a score or a gross or a dozen or a hogshead was, you got some sense of the scale of the thing from context. "I only asked for a few score of them, but they gave me a whole gross! How can I ever carry that many eggs home?" So, give them a plethora of vague measurements, rather than numbers. If they have reason for more specific numbers in the dialog you are writing for them, then that means they have a need to measure stuff more carefully than their approximate grouping nouns permit them to. That in turn means they are at a technological stage where that matters, and your rationale for having them not use numbers no longer holds up, and probably needs reexamining in the context of your world. --- Edit: Since this became the accepted answer, I thought it best to add a little hard data in here. So, to give some measure of how rare exact numbers are in common writing, I gathered from the Gutenberg project a few books and checked them to see how many numbers they contained, compared to how many words. So, appropriate to the discussion, here are some numbers! * Brahm Stoker's Dracula: 359 numbers in 148,036 words. * Peter Pan: 88 numbers in 42,928 words. * War and Peace: 1,169 numbers in 512,229 words. * Pride and Prejudice: 147 in 110,865 words. From this, we can see that numbers appear about one time in 500 to 1000 words. Reading through, I found that many seemed to be used to describe time (people's age, time of day, number of minutes' wait, etc); distance (twenty feet away"); currency ("ten pounds"); and as identifiers in addresses ("at number 27"). Of the remainder, many were used vaguely "five or six", or as superlatives when it was clear that the speaker was not actually confident in the number ("must have been twenty of them!"). Others were used specifically to make the reader's eyes glaze over: one third of the numbers in Peter Pan appear in a single passage with the father trying to do math out loud and getting it wrong. I was very hard pressed to find a case where a precise number was specified as something other than an identifier, and where the precision would actually matter, to the speaker, listener, or reader. [For anyone choosing to reproduce or improve on this rough test: I used the plain text versions of the books, stripped off everything above the beginning of the first chapter (contents page, etc), and everything from the last line of the original book (Gutenberg license etc). I then globally regex-replaced the term `chapter \d+` with 'Chapter N'. To find the numbers, I searched for the regex `(?!\b[0-4]\b)\d+\|\b(five\|fifth\|six\|seven\|eight\|nine\|ninth\|tens?\b\|tenth\|eleven\|twelve\|twelfth\|thirteen\|foureenth\|fifteen\|twenty\|thirty\|fourty\|fifty)` - to find the words, I searched for `+` (one or more spaces)] [Answer] MAKE SPIKY CLUBS FAST!!! Hello, not-tribe-member. Urk name Urk. Many moons ago, Urk in bad way. Urk kicked out of cave by Thag. Thag bigger than Urk, Thag take Urk spiky club, Urka (Urk wo-man). Urk not able kill deer, must eat leaves, berries. Urk flee from wolves. Today, Urk big chief. Urk have best cave, many wives, many spiky clubs. Urk tell how. WHAT DO: make one spiky club and take to cave places below. Add own cave place to bottom of list, take cave place off top. Put new message on walls many caves. Wait. Many clubs soon come! This not crime! Urk ask shaman, gods say okay. HERE LIST: 1) Urk First cave Olduvai Gorge few) Thag (not that Thag, other Thag) old dead tree by lake shaped like mammoth few) Og big rock with overhang near pig game trail Many) Zog river caves where river meet big water Urk hope not-tribe-member do what Urk say do. That only way it work. [Answer] If you aren't familiar with it, I suggest you read "Watership Down" by Richard Adams. Its characters are rabbits who are asserted to be able to count to four, but all greater numbers are equivalent. There is a word in their language (hrair) which is sometimes translated as "five" and sometimes as "a thousand". The author is consistent about it, and the dialog around numbers feels natural to me. (Besides, it's a good read IMO.) Also, look at how counting develops in early childhood. For a while before they can count -- age 2, maybe -- kids can handle one-to-one correspondence. They can, for instance, put get out one cup for each plate, though they may need to physically pair the objects to get it right. They may or may not be able to put out a cup for each person in the family -- one-to-one correspondence between physical objects and a list of people, some of whom aren't present. That's considerably harder. [Answer] Humans do not automatically count. In fact even up to the medieval era and probably beyond many people never had any numerical education. In fact it might still be practiced in large area's of Africa (1). The idea is to simply tie a knot for every count. You've got 18 cows? Well you have one knot per cow (or in case of more advanced area's like wild-west ranches they might tie 1 knot per 10+ cows because of the volume of cows they had to count). You can also keep track of the amount of months pregnant, baskets of fruit collected etc this way without having any concept of actual numbers. "How many banana's you want?", hold up a rope with knots, "this many". 1: <https://books.google.nl/books?id=X7SPDwAAQBAJ&pg=PA81&lpg=PA81&dq=counting+cattle+with+knots&source=bl&ots=WGXqVjXqKW&sig=ACfU3U2z9E3zBmLCMjm0lVf0FKEMNkCoJQ&hl=en&sa=X&ved=2ahUKEwix1rmW_KrjAhXDb1AKHcgnCNcQ6AEwFHoECAUQAQ#v=onepage&q=counting%20cattle%20with%20knots&f=false> [Answer] You can miss the counting ability, if you can still compare the relative size of sets. To give an example, you don't need to know that a basket contains 20 apples and another basket 40 apples, if you can tell which basket has more apples than the other. More often than not what matters is the relative size, not the absolute size. Other examples: * Is that group of attackers bigger or smaller than the group I am in? * which of those herds of preys is the biggest? * which pond contains more water? * kids not yet taught to count money preferring 20 5 cents coins to 2 1 Euro coins Summing up, make sure they can convey the concept of bigger and smaller. [Answer] Take a quick glance at a close group of 5 things. Your brain can just tell, without really trying, that there are 5 things there, right? It's even easier with four or three, especially if the objects are arranged in familiar patterns, like a square or a quincunx (i.e., the pattern of dots for the number 5 on a die). Now, take a quick glance at a group of 20 things. Unless they were specially arranged into quickly-recognizable subgroups (say, a square of quincunxes), you almost certainly couldn't just intuit their number. Now, try it with a hundred and two things. I don't care how they're arranged, there is no way (unless you are an autistic savant) that you are absolutely sure there weren't just 101, or actually 103, items in that group without some careful conscious counting. How they are arranged (i.e., in a nice grid with obvious small remainders, vs. randomly scattered) can make that conscious process easier or harder, but you definitely won't just automatically know. So, the structure of your brain prevents you from intuitively understanding groups of more than about 7 things at a time, maybe up to 20 in special cases. You are only able to handle larger precise quantities because your brain does have some fairly sophisticated abstraction abilities, and you were taught the cognitive technologies of counting and arithmetic. Even after you are taught those technologies, though, most people have no real concept of, e.g., the difference between a thousand and a million--they are just "big numbers"; your ability to distinguish them is purely a matter of abstract formal symbol manipulation. You were taught those cognitive technologies because you live in a civilization which places value on keeping track of precise quantities--e.g., for tracking debts and commerce. So, how do you keep your sub-humans from developing counting? 1. Make them incapable of the necessary level of abstraction. Sounds like you've already done that, if they can't even comprehend "beauty". 2. Make it irrelevant and unnecessary to them. Once you have more than 3 of something, why does it matter exactly how many there are? "Many" is enough. As for consequences for their ability to communicate... well, obviously, they wouldn't be able to communicate precise large quantities. But if that isn't important to them, who cares? It just won't come up. Now, the difference between exactly 4 rabbits and exactly 1 million rabbits may indeed be relevant for things like organizing hunting parties, but exact numeric quantities aren't--they could simply say "small group of rabbits" vs. "big, big, group of rabbits!" and get the necessary point across. Or simply focus on what the necessary consequences are: e.g., rather than saying "there's a group of 5 lions coming", just say "we need many fighters to defend from a group of lions!"--and if there's a whole pride of lions coming, who cares exactly how big it is, just say "we gotta move the village, 'cause we can't fight that group of lions!" [Answer] ## It's not possible for your creatures to not be able to comprehend large vs small groups. [Even bees can do this.](https://bigislandbees.com/blogs/bee-blog/14137357-bee-dances) > > Waggle Dance: Purpose is to explain the distance, direction and > desirability of a nectar source farther than 10 meters. In this dance, > the bee makes two semi-circles and then runs the diameter of the > circle. The straight side of the semi-circle shows direction, the > running speed shows distance and the intensity shows the nectar’s > sweetness and quantity. > > > Heck, [bees can also do math](http://blogs.discovermagazine.com/d-brief/2019/02/07/honeybees-can-count-add-and-subtract/#.XSX3K5M2qSM). Including [understanding the concept of zero](https://www.sciencedaily.com/releases/2018/12/181221123718.htm). Bees have tiny brains and no expressive symbolic language, though they can retain symbols presented from human researchers and they have precise communication skills with other bees. Ants are also [able to communicate that a food source requires more workers to carry](https://www.cell.com/current-biology/pdf/S0960-9822(06)01834-3.pdf), but it's unclear if they can convey quantity beyond "I need backup." This isn't limited to social animals with "hive minds." > > Scientists have found that animals across the evolutionary spectrum > have a keen sense of quantity, able to distinguish not just bigger > from smaller or more from less, but two from four, four from ten, > forty from sixty. ([ref](https://www.nytimes.com/2018/02/05/science/animals-count-numbers.html)) > > > After giving countless examples of animals counting, distinguishing group size, and doing math, they conclude: > > It’s not out of the question that you could have been wandering > around 15,000 years ago and encountered a few of the last remaining > Neanderthals, pointed to yourself and said, ‘one,’ and pointed to them > and said, ‘three,’ and those words, in an odd, coarse way, would have > been understood. > > > I challenge your assumption that it is possible for these proto-humans not to be able to distinguish between large and small groups or to do other basic counting and math skills. If they have any language at all, they will have words, or at least gestures or intonation, that convey size. It may not be with precision. They don't have to have any sort of writing system. But it will exist. [Answer] # What are they seeking ? Your species seems to have evolve language for some stuff but not for others. As we currently know it, the first human written stuff ever was probably accounting, who exchange how much to whom. Which is exactly what your species doesn't give a damn about. So they are probably eating enough, living well enough, and don't need to exchange stuff. Or they are definitely enjoying a anarchic heaven where there is enough of everything for everybody, and sharing is not even an action but a state of things. So they speak only to go on adventures, describing what there is and what could be, sharing previous discoveries and geography, describing the world with "few/enough/many/too much" stuff, no notion of distance other than a day of walk. So, basically, they just don't care. like hippies with an unlimited amount of pizzas, beers and no idea of what scarcity even mean. Why would they care about number then? [Answer] They might start referring to a group of something by the outcome you can get out of it. A single rabbit is a snack. Twenty rabbits is a feast. This has the effect that the same term can account for different numbers. Two deer may make up a feast. They're not really concerned with the number of souls that are being taken, they only think about the amount of food there is to be had. This can be achieved with any measurement you want. A cup of water is a sip. A bolt of leather ranges from a rag to a rug. Things weigh between a stone and a boulder. This sort of communication can convey enough meaning to get the general idea across. ]
[Question] [ I am trying to create a world where, on a Earth-like planet, a certain area experiences a peculiar phenomena: year after year, in a given period of the year, for a certain number of days (greater than 1), they uninterruptedly see, from dawn till dusk, a rainbow in the sky. In the early stages of their development, the inhabitants of this area took it as a sign of the place being blessed by the divinity, and therefore settled there. However I am interested in understanding if there is a (set of) physical phenomena which can explain that permanent rainbow. The rainbow shall be visible against the sky, so I am ruling out explanations like "there is waterfall". [Answer] A rainbow as we know it is due to refraction of sunlight (or other continuous spectrum, nearly point-source light) by large number of water drops (typically either falling as rain or from a sprinkler system, but it can also happen with clouds). The rainbow forms a circle at 49 degrees angle from the antisolar point -- which we normally see as an arc, interrupted by the ground, but from an airplane or mountain top it's sometimes possible to see a full "glory" -- a circular rainbow. A mountaintop with reliable cloud cover below and clear sky above would be an ideal place to see this. A glory will be visible in clouds below the observer when the sun is above, providing the water droplets in the cloud are in the right size range and sufficiently uniform in size. There are mountaintops on Earth (the Pali on the Big Island of Hawaii is one place that comes to mind; various peaks in the Alps as well) where these are common. All that's required for them to be everyday is sufficiently consistent conditions producing the right water drop distribution. [Answer] Ice ring [![circumzenithal arc](https://i.stack.imgur.com/QeQf4.jpg)](https://i.stack.imgur.com/QeQf4.jpg) <https://en.wikipedia.org/wiki/Circumzenithal_arc> Your planet has a Saturnine ring of ice crystals. Just as ice crystals high in Earth's atmosphere can produce rainbow effects, when the angle of the sun as relates to ring and viewer is correct the ring will appear as a rainbow to persons on the ground. [Answer] I'm gonna go with a different answer here, and that is: # Psychedelics in the water / air / land Is it unreasonable? Not necessarily. There are over 200 species of fungus that produce psychoactive amounts of the hallucinogen Psilocybin, and those species are found all over the world! The spawning period of this mushroom just so happens to be very regularly timed to one period of time during the year, where spores are released containing the psychedelic. I'm going to go ahead and rule out any earth species of mushroom, as stated in the question, the planet is not Earth, and as such isn't likely to have any of earth's species. However, there is plenty to take inspiration from, such as the tundra-inhabiting Gymnopilus, to the tropical Psilocybe. Why would mushrooms evolve such psychedelics on another planet? Easy. The psychedelic effect is meant to keep animals and humans close to the fungi, as any creature which passes away near the organism will inevitably become food for it. Is it possible to 'huff' a psychoactive dose of Psilocybin? absolutely. The active dose is as low as 1mg, or about 1/4 of a grain of rice. I'd wager a bet that the average person inhales 10x more in dust every day. [Answer] Rainbows be the blessing of Prisms So we need something glassy in the atmosphere, at least during sunlight hours, for at least a single day. 1. The planet has an eccentric orbit So much so that during the height of summer the atmosphere is just about swimming in humidity due to oceanic evaporation. For a period during high summer, it's consistently high enough that it can't drop enough at night to avoid the rainbow at dawn. This would likely cause better-than-average storms, too. But let's ignore those. Maybe your people live in what at all other times of year is a desert, so the storms are minimized. It would also be a period of lush growth — but not quite enough humidity to encourage rain. Tough balance. 2. When a particular species of tree blooms, it releases moisture A similar effect could be achieved with spring respiration. As part of the tree's/bush's reproductive cycle, it dumps a ton of moisture into the air. When the sun's up, of course. 3. Or maybe that tree's pollen is translucent Or the pollen or seeds could be crystalline or be surrounded by a sheet of translucent gooey substance that would encourage germination once a seed hit the ground. While in the air, it would serve the same prismatic purpose as water. 4. How about a fine mist of a meteor shower? Earth has its fair share of predictable and periodic [meteor showers](https://www.amsmeteors.org/meteor-showers/meteor-shower-calendar/), why not your world? The difference is that this particular meteor shower is the result of well pulverized mass that has a very high water content. Rather than resulting in lovely streaks in the sky, it results in high upper-atmosphere humidity. The rainbow isn't so much a bow as it is a ribbon, but just as prismatic. [Answer] It's pretty specific circumstances. The sun is moving in an arc. Depending on year and latitude, it could be from less than 1° (just below the polar circle in midwinter) to 360° (polar summer). Natives will see the rainbow if the sun goes over their heads into some particle cloud that refracts light. So for the rainbow to last all day, the cloud needs to be an arc around the natives, as wide as the Sun's arc. In theory, it would be enough if the cloud moved around the inhabitants. I can't think of a mechanism that would do that - maybe others can. Barring such a mechanism, this limits the arc to a maximum of 180 degrees - at that point, you'd have some permanent cloud front and the natives living on the edge. Doesn't quite fit your requirement that it's a single location, the phenomenon would be visible along the whole edge. So you're restricted to some area where the Sun is describing an arc considerably less than 180° - maybe 90°? And it would have to be winter so the sun isn't up for more than 12 hours and you can't have that "all day" phenomenon anymore. With that, I arrive at this scenario: There's a fog-filled area. Accessible from just a single point, otherwise there will be too many points where you see the rainbow just for a short part of the day. A peninsula, maybe, and non-navigable waters at the border? Or maybe it's in a valley and accessible through just a single pass? That point gets Sun all day (if the weather is right- there are regions where the weather is actually predictable), and the Sun goes up at the 4-o'clock position and down at the 8-o'clock position, with the valley or peninsula opening across 10-o'clock to 2-o'clock, with the rainbow going up, around and down with the Sun. It's a pretty specific scenario, and it strongly depends on where the natives can move, i.e. their technological abilities - the whole thing will be totally demystified as soon as the first balloon goes into the area. If you aim for a stationary rainbow, that would require a light source that's brighter than the Sun. This could happen in scenarios where artifacts of a high-tech civilisation still function when lower-tech natives move in, but I doubt that's the scenario the question was asked for ;-) [Answer] ## Geology & Astrology: All these answers are good, but let's get a few out-there ideas with a different slant. While cyclical predictable weather seems fairly plausible, light and heat can also follow cycles. * It only looks like a rainbow: Because it occurs only during specific days of the year, maybe it's a trick of the light. Certain areas of the world have [geological features that are rainbow-colored](https://www.youtube.com/watch?v=fnZOrCzqoWc), and if the light shone on them just perfectly on only certain days of the year, the rainbow effect might not be prominent at any other time. Unique lighting would likely be tied to the summer or winter solstices, which lends itself well to religious meaning. * Mineral rainbows: A natural geological structure is full of aligned [prismatic minerals](https://geology.com/minerals/crystal-habit/#:%7E:text=Prismatic%20is%20a%20habit%20name,augite%2C%20diopside%2C%20and%20topaz.). These minerals only get light from the correct direction shining on them at certain times. The effect is always present, but because it's so much more prominent on specific dates, and only observable from certain places, the people are always looking for the effect at those specific places and on those specific dates. Again, the most likely dates for these times would be around solstices, with the associated religious connotations. * Geysers: There is a stable geological formation like in Yellowstone National Park, where a set of [geysers](https://en.wikipedia.org/wiki/Geyser) build pressure and release steam once a year for several days until the pressure re-equilibrates and shuts down. Geysers can be highly cyclical and predictable (depending on the geology). The presence of hot springs can also be a positive for people who might be attracted to the free hot water. So people may have come for the springs and settled due to the 'miracle' rainbows. * Solar flares: Your world has a highly predictable [cycle of solar flares](https://en.wikipedia.org/wiki/Solar_cycle) that recur on an annual basis (tied to some astronomical event?). Like a variation on the northern lights, specific regions tend to manifest atmospheric phenomena on the dates that solar flares occur. Because all such 'sacred' locations exhibit this phenomenon on the same dates, when the specific astronomical events occur, all locations which have this (likely correlating with a spectacular period of aurora borealis activity) are seen as sacred. So you one location may not be totally unique, but the fact that all such 'sacred' sites are tied together makes it more, not less sacred. [Answer] A geyser. It can also have the feature of the eruption at fixed time intervals which would fit your requirement. ]
[Question] [ # Background A relatively recent planetary colony (<50 years from colonization) on planet A1 of star system A, that has just a few years ago become self sufficient (Can produce every product needed by its people on its own planet) has been attacked (as part of a conflict including multiple systems) such that several of its satellites/stations in orbit have been destroyed, triggering a Kessler Syndrome completely annihilating all orbital facilities and making it impossible for any current spacecraft to leave the planet. How can the people of this colony clean up their orbit and enter space? ## Sci-fi tech Other than the below-mentioned FTL and spaceship drives capable of propelling spaceships at fast enough (as is required) sublight speeds, all technology in this setting is as "near-future" as possible. That is, something is allowed only if it is supported by our current understanding of physics. ## FTL FTL is only possible a certain distance away from a star. Basically, the "edge of the system" (~40-50 AU) This is true not only for mass but also signals. Thus, during colonization multiple stations were set up at this distance. However, the presence of FTL signals is easy to detect at huge (100s of AU) ranges, so FTL stations can't hide. Consequently, they were all destroyed during the attack. ## The Attack The system A has very little interstellar infrastructure built in it (Comparatively. They still would have at least as many satellites in orbit as Earth, if not more. This is about infrastructure not in orbit). So, an enemy force gains very little advantage from conquering it as they would have to build a lot of infrastructure. Even occupying it would noticeably reduce their fleet strength, which they desperately need. So they sent an unmanned suicide attack. These drones destroyed their FTL stations, cutting the system off, they destroyed most space structures (and no remaining structure is self sustaining in the slightest), and they then attacked the orbit of A1, getting destroyed in the process. This attack cut off this system from any allies, but the enemy didn't send any actual fleet here. That is what the colonists are afraid of - that an enemy fleet will come here when they can finally spare the resources, and they want to make sure they are as prepared as possible. If they do come, if they are prepared, they can send an FTL signal to allies. If they are not prepared, no one will know they have been occupied. ## Communication The system is very far away from any other inhabited system, allied or otherwise. Lightspeed signals will take decades to get there, while a signal being sent from under atmosphere might not even be strong enough. Though the cessation of communication is a giveaway to allies that this system has been attacked, they are too focused on fighting the war to spend much resources on reestablishing contact, unless the enemy fleet actively occupies this system. Moreover, this system is just one of many colonies on both sides that have been attacked with the goal of cutting them off. All to say there is no help coming from outside, the colonists must do everything themselves # The Question As the leader of the task force formed to clean up the orbit of A1 and re-establish space operations, what can I do to achieve this goal as soon as possible? [Answer] Important things to remember about orbital mechanics: * not all orbits are equally useful * where less useful orbits intersect more useful ones, the less useful ones will not be used * changing the plane of an orbit requires a lot of energy What this means is that surprisingly big chunks of sky will not have much debris in them... especially directly over the poles. If you had access to suitably powerful rocketry (and if you can engage in interstellar colonisation, you almost certainly do have this) then you can potentially squeeze some flights out into odd trajectories from where they can escape or punt themselves into more useful higher orbits which will be debris-free. If even these windows aren't safe, you can reasonably assume that they will have much, much less debris in them (because most stuff will be in equatorial orbits and even really big bangs can't spread it very far polewards). So what you need to do first is to find out where all the debris is. [![Space debris around earth](https://i.stack.imgur.com/tShdc.png)](https://i.stack.imgur.com/tShdc.png) [Source](https://www.michaelnajjar.com/artworks/outer-space#58) Depicts objects larger than 1cm, in 2012 You'll be needing a set of powerful, high-resolution radar stations capable of imaging millimetre-sized debris. These will be pretty specialised bits of gear, and won't always look much like regular radar facilities. Here's one NASA uses to track things as small as 2mm in LEO. Its a 70m dish! [![NASA Goldstone 70m antenna](https://i.stack.imgur.com/cqpZg.jpg)](https://i.stack.imgur.com/cqpZg.jpg) In combination with slightly less specialist gear for tracking larger objects, a detailed catalogue of debris orbits can be made, then a plan made to clear out some launch windows, at which point you can break out the [laser brooms](https://en.wikipedia.org/wiki/Laser_broom). It probably won't look quite as awesome as this, but you've got to admit that the picture is pretty: [![Laser broom debris clearance](https://i.stack.imgur.com/1Gaht.png)](https://i.stack.imgur.com/1Gaht.png) Note that you want to deorbit stuff, not blow it into more pieces! Toast gently, don't blast. Once you've made a little launch window you can start launching small, heavily armoured satellites into high orbits to make use of high intensity 24hr sunlight to drive lasers unobstructed by atmosphere to do the real serious work of deorbiting debris, and get back to filling up your orbits with your own rubbish again. [Answer] They can fire very powerful lasers to the sky, either from ground bases or from air carried systems: some of the targets will simply be vaporized by the beam, some other will get a jolt which would alter their orbit, resulting in an increased drop rate. Rinse and repeat. [Answer] Two main ways: * Lasers fired from the ground. By slightly applying thrust to each chunk via lasers fired from the ground the orbits can be tweaked. Eventually causing the chunks to burn up in the atmosphere. * Tiny robots that know orbital mechanics. If your robots can get to one chunk and there are lots of other chunks to choose from, the robot can pick a course that allows it accelerate itself off chunk 1 towards chunk 2 such that chunk 1s orbit changes enough that it will eventually reenter. The robot then repeats jumping from chunk to chunk, bumping each chunk into an orbit which reenters via the combination of momentum applied by it arriving and departing from it. + Assuming all the orbits are randomly distributed, I reckon theres a optimal path allowing a single robot to de-Kessler a planet of all objects over size N without expanding any propellant after arriving in orbit, just jumping from chunk to chunk. I lack the patience to prove such an assertion, so just launch 50 robots and odds are good itll be done. [Answer] Use an asteroid as a vacuum cleaner That asteroid those colonists where slowly maneuvering into orbit around the planet so they could mine it, they decide instead to put it into a high eccentricity orbit around the planet. As the asteroid goes barreling through the debris field fun things start happening. There will be a minor benefit from some debris colliding with the asteroid (so pick a target orbit for the asteroid that intersects with the biggest chunks of debris). But the main aim is to start scattering the debris. The planet, asteroid, and any single piece of debris now make a three body system and three body orbits can easily scatter the smallest object into a new orbit. So we will either end up sending the debris inwards (which will burn up in the atmosphere), outwards (easier to avoid when launching your next spaceship), or into an eccentric orbit itself which will rapidly de-orbit due to gas drag as it approaches the planets atmosphere. [Answer] ## Kessler Syndrome does not pose a significant problem. * In general, the problem is overrated, in some sense, sure it a big deal when if happens, but as aftermatch... * Also, it requires a particular set of initial conditions to be in place to happen at all. We can imagine these conditions to be fulfilled. Yeah, invasion blasts everywhere, can it wreck the whole satellite system - yeah, why not, but it won't be for the reasons Kessler imagined, it'll be some external factor. And that external factor may clear itself soon after, like a cloud of debris fly by, meteor shower, etc. Yes, it wrecked the system, but then the factors are not sufficient for Kessler to continue - if you put some satellites back as an example, yes, there can be plenty of debris there, and you need to put replacement sats more often - but it not like you're out there and 5 second later your satellite or station is hit dead. As Starfish pointed it out in his answer: not all orbits are the same. So it needs to be understood what that debris field potentially is, and deduce that. Depending on the situation, different orbits will have different lifetime, which will depend on how robust the crafts are, relative velocities, densities of debris, sizes of them, and so on. In general, there will be some average lifetime of the orbits you need, so there will be similar orbits which are safe enough. It needs to be noted that some low orbits - in case of our planet these are 100-400km - are naturally self-cleaning: no small debris will orbit there for long. A 400km circular orbit will decay into the atmosphere in less than a year for objects with density 300 kg/m3 and crosssection around 50 square meters (Mir space station), or - if we recalculate it - a bolt made out of metal, with a mass around 750kg, will enter the atmosphere in about a year. Those which are smaller will decay faster, because of volume/surface dependencies. (These numbers are very approximate, I got them just by eyeballing some [Orbital decay](https://en.wikipedia.org/wiki/Orbital_decay) pictures for space stations.) So, even if the situation happens, it does not prevent access to space. Orbits we consider as passable qualities -like the ones for current space stations - will self-clean quite fast from small particles, and you need to monitor and track big enough particles. ## I need it to be cleaned by yesterday Depends on how much effort you put into it, but not impossible. And presumably, your launch capacities and satellite manufacturing are not affected. No problem then, launch capture satellites, detection satellites, etc. The more you put of them, the faster you can clean it up. Satellites do have a different resistance for impacts, so use a bit reinforced one, some whipple shield ones - they are not necessarily heavier, they just have a simpler function to which a shield is not a problem, as it would be for some space telescope or transmission satellite. These can catch the debris. Utilize close range detectors for small debris, etc. Facing such a problem less efficietly, with a success rate of, let's say, 80% , aren't game-breakers, as failures do not spill more fuel on the Kessler fire, if youu do that strategically at lower orbits, and other smart ways. There are other ways to clean stuff, but it needs to be understood that no matter the severity of the Kessler syndrome, it doesn't cur your abilities to solve the problem by launching satellites that do the cleaning job, so you don't have to jump right to some laser solutions. There are satellites that obit under propulsion, at lower orbits, and which do change orbits - some experimental/testing(?) military satellites. And there are air-breathing ion engines, and this combination allows you to build a system that will wipe your orbits clean as new, over a reasonable time, like a few years. It's just a matter of effort to launch them. Any space-faring colony should have no problems with doing that and face the debris problem. [Answer] They don't. If your colonists are deathly afraid of the enemy coming to invade them, then the debris serves as a shield while the planet develops surface weaponry. If anything, it lets them build more effective weaponry since they don't need to worry as much about adding debris to their orbits. Then they wait for reinforcements (and for space based cleanup from the homeworld). This is a siege. One where the castle doesn't need to worry about growing enough food or finding enough clean water. [Answer] For a less scientific answer: The [KatamariDamacy](https://en.wikipedia.org/wiki/Katamari_Damacy)[@home](https://en.wikipedia.org/wiki/List_of_distributed_computing_projects) project. Launch balls of solar powered 'sticky stuff' into orbit that can be controlled by users at home. You have large number of students and others spending countless hours trying to maximize the path to increase their 'ball size' to make the top rankings. Note that it doesn't necessarily have to be actually sticky. It could be inertial dampeners or some advanced tech like that. [Answer] Similar to Telastyn's answer, they sit tight and build an on-planet intrasystem missile system to defend A (i.e. when the enemy tries to build infrastructure somewhere in A, it is destroyed from A1 with a missile or three. One other thought I had - the problem could be a designed Kessler syndrome producing system. Not just satellite debris, but an enemy-made high-tech satellite system which actively goes after launched rockets. ]
[Question] [ In my science fiction story,there is a phenomenon happening on the moon that looks like a red mist (or nebula, if you will). This mist can slowly move around, because it is controlled by an advanced alien civilisation. The nature of its sentience and movement is irrelevant here: my imagination can take good care of that,and I don't have to explain every detail in a sci-fi novel, for obvious reasons. However, I have a chapter when an astronaut investigates the phenomenon, and an automated drone is sent to take samples. The astronaut will look at these samples, and will find what it consists of. So, for this "scene" it would be good if I had something specific: you know, particles of some sort, chemicals or anything that could be inside of this "mist" (it can also be similar to a cloud of sorts). Note that at this point of story I don't want to give anything obvious like "this thing is alive, it is an alien! It has sapience!". At the time of the scene, scientists will already know that it is something caused by aliens, but not that it has any supernatural properties or IS an alien. So I need something fairly normal, like the astronaut finding out that "this thing has trace amounts of #1, but mainly consists of #2". So here comes the real question: what kind of gasses/chemicals/whatever could cause such a phenomenon as a red nebula or mist (or something that could look similar)? If it can't be red, feel free to suggest some other color. [Answer] [Tholins](https://en.m.wikipedia.org/wiki/Tholin) Tholins are organic compounds that are typically found on cold outer solar system bodies (e.g. they are responsible for the prominent red patches on the surface of Pluto, and snaky lines on Europa). They are (no longer) found naturally on the Earth, as they would quickly react with oxygen, and I don’t think are found at all on the Moon (perhaps they would break down in the high temperatures of the lunar day). So the presence of tholins on the Moon would be both noted (because they would stand out against the grey coloration of the surface) and notable (because they shouldn’t exist for any length of time naturally). Tholins can be found as aerosols on outer solar system bodies with an atmosphere. Again, being found in that form on the Moon, which effectively has no atmosphere, would imply some active process to maintain it. Apparently the derivation of the name is from a Greek word meaning “hazy”, so that also fits with your narrative. [Answer] Iron Dust Mars has its reddish complexion due to iron oxide (rust) on its surface. If you had something to stir up rusty iron dust then it would look like a reddish cloud. [Answer] Blood. [![blood](https://i.stack.imgur.com/tup1S.png)](https://i.stack.imgur.com/tup1S.png) <https://en.wikipedia.org/wiki/Acanthocyte> Your astronaut looks at the sample under a microscope. It looks like blood. In the simple lab that the astronaut has, the stuff breaks down as blood; lipids and organic molecules. It is apparently a mist of blood. It is actually a self replicating organic nanobot. Regardless, the astronaut should not have touched it. [Answer] ## Garnet dust [![enter image description here](https://i.stack.imgur.com/6qQk2.jpg)](https://i.stack.imgur.com/6qQk2.jpg) [source](https://commons.wikimedia.org/wiki/File:Teri_landscape_near_Kayamozhi.jpg) This is a [Teri dune complex](https://en.wikipedia.org/wiki/Teri_(geology)) in south east India, of which > > [t]he soil is rich in ilmenite and the red colour is derived from haematite originating from [garnet](https://en.wikipedia.org/wiki/Garnet). > > > Garnets are silicate minerals, usually of a red hue (see its etymology). [Answer] # Excited Neon Gas In the presence of an electric field, neon gas glows red. Otherwise it is colourless and odourless. [Answer] Bromine It's a red vapor in a fairly reasonable temperature/pressure range for a living organism, and is involved in organic processes, but is nasty to handle in it's elemental form. What more could you need? ]
[Question] [ I'm making a fantasy world and wanted to incorporate curses and geases into the story. When I say "curses" I mean two types, but mainly this: ![Greek Curse Tablet](https://i.stack.imgur.com/CElEM.jpg) The type where you write your curse and either: perform a ritual, break it, or maybe bury it. But the classic "fairy tale" curses (the kind where a witch turns up and curses a prince) would also be a thing. But the issue I've ran into is: people curse a lot and if every curse was valid that'd make the world a massive mess and trying to write a story a headache. So what I'm wondering is: Who or what would regulate which curses are valid and which aren't? For example: Why would a curse banning bishop Wulfric from building a cathedral over the ruins of the last one be valid while a curse forcing Otto to scream when he lies would not be? What I'm looking for in an answer for answers: * if it's a deity or entity a explanation why they have this power and ways they judge valid and invalid would be really appreciated * linking both spoken curses and written curses * and of course why daily curses like "I hate you Jim I hope you trip" seemingly have no effect, but cursed written in stone or spoken a different way do have an effect Bonus: Not required, but a way to balance these curses and maybe limitations to the extent of a curse would be greatly appreciated. [Answer] Curses, like any other prayer, are essentially a call to a supernatural power to do you a favor. In this case, the favor is that some harm come to some person. In a polytheistic society, you might call on the god or spirit that is most likely to be sympathetic to your cause. So, if you've been wronged in love, you might call on the God of Spurned Lovers to curse your betrayer. If you've been cheated in business, you might call on the God of Fair Dealings. Of course, one god may have many specialties (see the Greek Pantheon). An offering to the god makes the god more likely to grant your favor but they still might not do it if it is totally unjust. A mischievous or malevolent god or spirit might carry out an unjust curse, but it is dangerous to call on those because they are capricious and just as likely to target the user. The offering should be costly and specific to the god you are calling on and should be somehow spent or destroyed in the cursing (material offerings burnt, offerings of livestock slaughtered, etc). On the other hand, if your cause is righteous or particularly appealing to a particular god, they might help you out without an offering. All you have to do is call on the god and ask for their help in the right way. This could be the "witch showing up and cursing the Prince" type of curse. "Oh mighty God of The Decentralization of Power! I call on thee to curse this haughty prince who wishes to expand the powers of the monarchy! May all his endeavors fail and his life be hollow and sad! I beg of you to grant my wish!" So, you can't just go around cursing everyone, you'll go bankrupt, unless your cause is very, very righteous. Even then, if you call on a particular god too often, they may tire of you and your curse may backfire. And, "I hope you trip" curses are mostly ineffective; maybe a god will hear you say it, but they're unlikely to get involved in the petty squabbles of mere mortals unless they are particularly appealed to. Occasionally the God of Mischief might throw you one, but the odds are no better than chance. [Answer] The language that is used Saying "I hate you Jim and I hope you trip" in any common language means nothing magically. But saying it in the language of magic does. Unfortunately it's a dead language, and most people don't know enough to just curse everyone they come across. those that do know some, usually only know one or two phrases. There probably are some who know the language of magic fluently, but they also know... Curses are taxing Curses cost you something. In the case of the stone table, you sacrifice the stone when it's broken. in the case of the spoken curses, you become fatigued, maybe even age some. Yes you hate Jim, but is it worth a week of life, or needing to head to bed before lunch just to see him trip. It could be added that the stronger the curse, or more pronounced it is (a trip vs instant death) could cost you more. [Answer] Whim of the dark gods Gods are constantly barraged by prayers, pleas, begging and curses and generally ignore it but sometimes a curse carries enough hate, fear or malice to tickle the fancy of a dark god to grant it. These curses stand out from the background noise and draw attention and the dark gods are bored and need amusement. Think of it as a short story competition and the gods pick the winner. [Answer] You previously asked: [Why would "dead languages" be the only languages that spells could be written in?](https://worldbuilding.stackexchange.com/q/150022/21222) Supposing all magic is cast or written in an ancient dead language, there are some options that come to mind: 1. Some things are hard to say in dead languages. My latin is rusty; But I am sure even someone fluent would have a hard time using it to do modern day cursing. "May your downloads be slow and timeout often" could be hard to say without a lot of double meanings, and the curse might in very unintended ways due to that. My native language is Portuguese, which derives from Latin. Using the most orthodox translations of the curse above, and translating back and forth a few times, may end up back in English as "May your toilet flushes take a long time, and may you die frequently". Way to mess up a spell. 2. You don't actually move the universe by yourself with your spells. Each spell is a request to an astral entity, which may be more akin to an astral golem than a deity. That entity may either misunderstand and comply in a very stupid manner, or just ignore you and move on to the next curse in its queue. Optionally: no one can see or hear the phantasms. The enchantments for that were lost long ago. People are doing magic in a very cargo cult manner. 3. There is a price to pay for spells, in [ManaCoin](https://worldbuilding.stackexchange.com/q/112309/21222). It correlates not to how hard something is to do, but to demand. It may be that you don't have enough to pay for something because it is prohibitively expensive due to high demand. You are the only one who wishes Wulfric to gail at building that cathedral, so that's cheap. But everybody wants him to [redacted in order to be nice] go make love to himself, so basically no one has the ManaCoin to pull that off. This may be combined with idea 2. 4. [Magic is a form of programming](https://wiki.lspace.org/mediawiki/Hex). Some complex things are fairly easy to do with programming. The route-finding algorhitms for Waze and Google Maps, for example, are considered introductory material in computer science courses. Simple things, though, are hard to do with programming - [there is a one million dollars reward for anyone who can come up with an algorhitm that determines the best way to put stuff inside a box.](https://en.wikipedia.org/wiki/P_versus_NP_problem) So the astral golems from idea 2 might go: "Keep Wulfrich bishop from assembling big shrine (status new) on top of big shrine (status nullified);; : hex succeeded, 1881 iterations :: exit code = triumph" "Make Wulfrich bishop go love himself :: ERROR'D the response given was `caster does not have sufficient ManaCoin in stash` 3 iterations :: exit code = aborted" [Answer] The target/victim does, they have to believe that curses a) are real and b) actually work, and that the person cursing them is capable of performing a real curse. Combine that with the formal part of issuing a curse - "written on parchment buried under fresh cow poo and left on the targets door step, activated when the target steps in the poo" etc - to let the intended victim know they've been cursed. After all their belief in the curse/voodoo/hex/etc. won't do any good unless they know they have been subjected to one. And then after that, as Granny Weatherwax (mayhersoulhavemercyonthegods) might say it is all [headology](https://wiki.lspace.org/mediawiki/Headology). [Answer] The implementation of a Curse will depend on how your magic system works. So here is a part of my magic system for curses. Curses can be performed by Anyone, but the duration and power of the curse will really depend on the person casting it. Farmer Joe might curse his land lord, but without the proper sources of magic and will, it doesn't last long and is barely noticeable. Merlin on the other hand, with all his knowledge and artifacts, would curse someone for life. A God on the other hand, could curse a person and all their descendants. Now curses cost more depending on their duration and effect, but of course that is up to you to sort out the final details. In regards to a language, magic can be cast in several ways. For you curse system, magic can be cast using your will, or the written language of power. For will, as long as someone thinks it hard enough, it can occur. So farmer Joe can curse his landlord with impotency because he really really wanted it to happen as he cusses the landlord out for raising rent. Words are simply a coincidence, so your wise mage Merlin can curse someone without saying anything, or by saying some strange mystical blurb that no one knows. Other lesser mages, associated the word and effect, so when they cast the spell, they also will it in their mind and bring about an effect. Written words are a bit more mystical and heavenly. Usually its a special written language that when written or imbued with power triggers an effect. Basically you trigger the symbol with your magical energy and the effect will happen. Curse symbols combine the will of the person triggering them and the effect on the symbol. So with a fire curse, you can make the person you are thinking about feel like they are being burnt alive. The origin of such words or symbols are up to you. I choose to have a special language created by the gods, and this association with gods grant the words power. ( aka, The God says this symbol means fire, so when you write it down, boom fire). Now the easiest way to balance curses is the use of blessings. If Farmer Joe curse the landlord with impotency, why can't the landlords wife bless him with some extra energy to get him going? [Answer] ## Curses come with a heavy cost Curses are powerful magic, and powerful magic comes with a cost. All but the simplest curses also need some kind of intelligence to guide them; either some kind of supernatural being overlooking them, like a god or a demon, or the curse has a spirit bound into it. If a curse is cast as a spell or ritual, there may be extensive human sacrifice involved, or the caster must sacrifice some of their power or life force to create the guiding spirit. A witch of the cursing kind has typically made a deal with a demon or dark god to gain power, usually for a limited time (e.g. until death, but each use of magic ages the witch) or with a limited store of power. The witch pays the price, and the demon or god effectuates the curse. Then there is the dying curse; usually considered the most powerful sort. In this case, the curser (knowingly or unconsciously( dedicates their soul to a higher power in return for the curse, or they become a spirit that oversees the curse - similarly to how extreme hate or anguish at death will turn the dead person's soul into a ghost that haunts a place until given release. The cost associated with curses limits their use. It is not something done lightly. Also, spirits may only be bound into a curse for a limited time before they dissipate, die or can break free, and demons or dark gods may eventually tire of the game. The stronger the curse, the longer the term may be. [Answer] A believable and versatile way to handle curses is make their establishment/enforcement dependent on the depth of attention the cursing person has earned with a supernatural entity, and their curse's relative alignment with the will of that entity. For instance: A pious, humble man is mugged in the night. As he watches the mugger flee with his money, anger, fear, and frustration well up and he utters a Curse, "God will see you receive the same!" In that moment, the man's God, whose very partial attention was drawn by the sudden, out-of-character utterance of His faithful, mirrors, just slightly, the same indignation at such an injustice. Part of Him hears the Curse and, since its intent resonates with His own, the tiniest sliver of His power manifests to carry it out. Later that evening that same mugger cradles his own head in pain as another carries off the night's 'earnings'. In rage he utters a Curse, "God blight you eyes!". However, since this man's "God" was, publicly, the same one that carried out the Curse, the mugger was ignored and the curse had no power. Additionally, the God that the mugger really aligned with, a thieving and tricky fellow, found the whole thing hilarious and let the man wallow in his own self pity. Besides, why would he empower a Curse uttered against someone for doing what he would do? Anyway, you get the idea. You can also add additional power/depth/plot around Curses with Faustian bargains and deific favors. [Answer] The tablet isn't the curse. It doesn't need to be. Have you ever watched someone wrong you, and cursed them? Maybe someone blew through a red light, and you wished them ill. Most of the time you don't will them strong enough, but sometimes it happens. Sometimes the police officer is just 1 block away, and has already turned their lights on. Sometimes that's karma. Other times you feel bad. A ticket is one thing, but a car accident is nothing to wish on someone over a mere red light. When they get in an accident, you start to feel guilty. Why? Because the curse worked. Most of us can't curse coherently enough to do much more than that. It's difficult to hold a focus like that. If the average person tries, the curse gets diluted quickly... sometimes by someone else's curse. They may curse someone who drove through a puddle in front of them, and do so in a fuzzy enough way to accidentally curse your curse, weakening it. Some people can make it work. Generally we try to run them out of town with pitchforks and torches. As for the tablet? It's just there to help out using the power of language. Your true curse has no language, nor does it need one. You know exactly what you meant when you cursed. But if you're skilled enough at the cursing to curse along the lines of language, you may be able to make the curse more permanent. The language offers a scaffold of sort for the curse, helping maintain its meaning (over centuries if needed). Likewise, a deity is just there to help out. They may lend extra firepower if your curse is true to their nature. They may lend it if you give a little bit of yourself to them. Depends on the deity. Just be careful with those curses. The deities obviously have their plan for the game, and sometimes the curse doesn't quite go as you mean it when you let a deity take over it for you. Better to pin it down with words instead. As for balance, what if the curses don't exist? What if they're just a subjective illusion? What if that guy was going to get a ticket whether or not you willed it to happen? What if people really do just drop dead for no apparent reason? Uncertainty and doubt balance out curses rapidly. The more nuanced the curse, the harder it is to have developed a mind that leads the curse to come to pass. And as for those minds that can curse, and curse well? Well the balance is even simpler there. It's as age old as time. Be careful what you wish for. [Answer] ## The curse itself Curses are spells, they need to be preformed very precisely. Things like cadence, intonation and word choice all affect the outcome. There could be even more requirements like the correct posture or cardinal direction of the speaker or something sillier like you have to circle your mouth with your tongue after speaking every O. Similar requirements (wording, kerning, the paper that's used) exist for written curses. Everyday curses use the same or similar words, but they have no effect, because the other requirements are not met. They came about, because people saw actual curses having effect and were trying to replicate them. ## Emotion The curse would take effect only in the most extreme circumstances, based on how much hatred/desire/anger you could pour into the words when speaking them or writing them down. Most curses would only take hold when spoken by people who have been done a great injustice. Saying "I hope you trip" doesn't have nearly enough emotional power behind it to work. Witches/warlocks could be people who have mastered controlling their emotions and can replicate that sort of emotional state on command. ## The law A bit of a different take, but curses are one-sided legal contracts in this world. When performed correctly, and after submitting the appropriate paperwork, the cursed is mandated to follow whatever requirements the curse put upon them or face much more horrible consequences handed out by the state. [Answer] Think of curses as as a stream of dark energy. In order for it to manifest, it has to solidify itself as a spell. However, the process of solidification is quite intricate. It depends on various factors such as intent of the person casting the curse, resistance of target, process involved in incribing the curse etc. Also, proper manifestation of spell requires a step by step ritual to be followed by the person casting the curse. Moreover, the curse intensifies if more people wish for that to happen. When the person curses someone, a stream of negative energy releases from its body creating a void within him. Greater the curse, greater is the void created within. However, this void makes the spellcaster more susceptible to receive curses from other sources. Hence, the natural healing mechanism of the body kicks in, absorbing the curse back and filling the void. The rate at which the curse is absorbed depends upon the intent of spellcaster. More malicious the intent, greater the rate of spell solidification, lesser the rate of reabsorption. So the daily curses like "I hate you Jim I hope you trip" seemingly have no effect as the spellcaster does not have malicious intent towards the target. Curses like these, spoken at the spur of the moment, are quickly absorbed negating it's effect. But curses written in stone or spoken a different way do have an effect as they are cast on purpose. Spellcaster has a malicious intent towards the victim and he wishes the curse to manifest and this accelerates solidification of curse into spell, thereby reducing its reabsorption. If the spellcaster's intent is strong enough, it also casts a rudimentary protection over the void created within to reduce its natural healing. Yet, the intent itself is not enough for casting more complex curses. Normal folks with minimal spellcasting knowledge can make their curses effective with right intent, but it requires a real wizard/witch to cast highly devastating curses. Greater curses create greater voids thereby increasing the rate of curse reabsorption. A wizard/witch knows the exact ritual that seals the void created before the healing mechanism kicks in, thereby stabilizing the curse. The curses cast by specialists are more stable as they seal the void completely. As long as they can maintain the seal, the curse is effective. Greater the wizard/witch, greater the amount of void they can seal, greater the curses they can manifest. However, they have to be careful in estimating the amount of void they can hold. If they are not able to hold the void, the curse retaliates and brings their own destruction. To overcome this problem, many witches and wizards work together to hold the void together. Many of them also exploit the intent of others to strengthen the curse. For example, for banning bishop Wulfric from building a cathedral over the ruins of the last one, the wizard exploits people's grudges against bishop Wulfric and their intent against building the cathedral and links them with the curse to strengthen it. To carry out the curse of such magnitude specialists are required and someone would definitely ask for services of the wizard thereby making it valid. While a smaller level curse like forcing Otto to scream when he lies would be cast by a normal folk with hardly any malicious intent on a deeper level making it invalid. [Answer] I'd much rather leave a comment, but I don't have enough reputation to do so. I'd like to build on [IAntoniazzi's answer](https://worldbuilding.stackexchange.com/questions/151200/who-or-what-determines-if-a-curse-is-valid-or-not/151204#151204): If making sacrifices to a certain god or aligning to their cause makes them more likely to carry out your curse for you, then certain individuals with a long history of favouring certain gods will have an easier time convincing said gods to curse their target. Some nobody might get a god to look their way if they perform a lengthy, rigorous and expensive ritual to place a curse on somebody, but an ancient, powerful witch who's served said god their whole life or at least carried out sacrifices and offerings often will be able to call on that god's help with a single word, being recognized instantly. [Answer] Geases are curses. Typically if someone breaks a geas they die. The main difference is that a geas usually has a condition attached to it like not being allowed to spill the blood of a boar. You have to assume that magic is a real thing, like a great unseen extra dimensional ocean. Deities have vast access to this ocean, spirits less so, magic users even less. So average people trying to curse each other have little chance of doing so because they just can't tap into that magic source which turns will into reality. Even powerful magic users are limited to what they can achieve because the human mind can't imagine the processes required to will something more complex to happen - willing a tree to come into existence requires more than just wanting a tree to appear - you have to know how a tree is formed and grows to will it to do so. So most human magic is limited to creating elemental effects like wind and fire or cursing people to get sick and die or change their mind over some issue. You could have groups of magic users coming together to perform more complex tasks where each user has focused on a specific piece of knowledge or even just to boost their connection to the source. So it becomes more useful to try and get a spirit or god to fulfill your wish. That requires payment of some kind, the more powerful the being the higher the payment with some tasks only being performed by certain spirits who might not be the best creatures to deal with. So perhaps you dedicate a temple or altar to a god or sacrifice the lives of animals or people - maybe giving up a valuable piece of jewelry or bags of money by depositing them in a temple or however else the being gets their reward. How do they hear your curse? You could write it down and then deposit it in a spring or other site where magical beings come near the mortal world. If you can't write then you make a voodoo doll with the hair or clothing from your victim attached to it or chant a curse into the doll - imposing your will on the doll and then sending that off like a letter to Santa. Chanting an incantation while sacrificing a living creature or valuables is another way. [Answer] > > I'm making a fantasy world and wanted to incorporate curses and geases into the story. When I say "curses" I mean two types, but mainly this: Greek Curse Tablet > > > The type where you write your curse and either: perform a ritual, break it, or maybe bury it. But the classic "fairy tale" curses (the kind where a witch turns up and curses a prince) would also be a thing. > > > There is only 1 type of curse. The kind that requires a ritual. The problem is basically noone really understands the rituals. They are far more complex than they seem. What is needed varies by what the curse does. And there are many rituals that can have the same effect. Basically, can think of each ritual as a list of rules that need to be followed. This is why sometimes random shouting can inadvertently cause a curse. Because by chance the circumstances were right. And why Curse Tablets sometimes fail. The makers know say 9/10 of the components of the ritual. What material, most of the actions, but they don't know the rest. It is also why witches exist. Turns out a common clause for many rituals is tied to the person making it. If the 7th daughter of a 7th daughter, born on a full moon, crosses her fingers and squints, then that is 95/100ths of the conditions for a multitude of different curses. [Answer] # Curses are fueled by a soul fragment of the caster Creating a curse is easy, you just have to put your soul in it, literally. Whenever you curse, a fragment of your soul splits off in order to form the curse. Maintaining the curse on the other hand, is difficult. The curse is still a fragment of your soul, and a soul desires to be whole. Therefore, the soul fragment and the original soul want to rejoin by their nature. With everyday curses, this happens instantaneous. Only with a lasting strong desire, be it born of righteousness or spite, the curse can endure over longer time. The curse does not require active maintenance, but it is still linked to your soul, so you need to believe in the cause of the curse. Once the belief wavers, the curse ends, but if it is strong enough, the soul rejoins the curse postmortem, which truly completes the curse. So in the end, it is your own mind which decides which curses are valid as they are anchored by intent. You can make Otto scream when he lies, but only if you truly detest his lying ways from the depths of you heart. It doesn't matter if the curse is written or spoken, it's the thought that counts. Although following the proper ritual helps to transfer the soul in a state where it is easier to split a fragment. Witches are people who have a broken soul, which means that their soul fragments do not desire to rejoin the original soul. This allows them to curse on a whim, but those curses are easier to break as well. ]
[Question] [ This question already has answers here: [Natural Projectile Weapons](/questions/541/natural-projectile-weapons) (12 answers) Closed 5 years ago. Projectile weaponry is not unheard of in the animal kingdom - cobra venom, venomous spider silk, velvet-worm slime, scalding water from bombardier beetles, archerfish spitting water, penguins expelling feces and petrel vomit are a few examples that I think of. However, these are all liquid projectiles, and I'm wondering about solid ones. Those are also seen in animals, but are usually limited to either fecal matter or objects from the environment. Some cnidarians also have nematocysts/cnidocysts, which is probably the closest real-life thing to what I'm getting at. My question is: could an animal, or animal-like alien, generate a solid projectile (Solely for the purpose of being fired) inside its body and then expel it with speed and force as a means of offense and defense? If you have any queries, or wish to notify me of an error, please say so in the comments. [Answer] Easy projectile - gastroliths. Many animals swallow small stones to aid in digestion. Maybe some sort of bodily function that generates stones thanks to a high calcium diet (or another mineral). As for the mechanism, as others have said, muscles probably won't cut it. An interesting solution is [found in the British planthopper](https://www.nationalgeographic.com/science/phenomena/2013/09/12/this-insect-has-gears-in-its-legs/), an insect that has gear teeth on the tops of its legs. They can wind into place, and allow the insect to jump some good distances with great coordination. Some adaptations could allow for similar structures that could process and launch these generated stones. [Answer] Take a [crested porcupine](https://en.wikipedia.org/wiki/Crested_porcupine) > > If continually bothered, the crested porcupine will stamp its feet, whirr the quills, and charge the disturber back end first trying to stab the enemy with the thicker, shorter quills. These attacks are known to have killed lions, leopards, hyenas, and even humans. > > > Give it a longer tail, and some muscles to detach quills at command. [![quills](https://i.stack.imgur.com/IC1NW.jpg)](https://i.stack.imgur.com/IC1NW.jpg) When the animal wants to launched the quills, it just has to swing the tail and activate the muscles with the right timing. The quills will fly like projectiles. Those quills are known to be extremely painful to extract, due to the conformation of their surface. [Answer] # [Urticating hairs](https://en.wikipedia.org/wiki/Urticating_hair) Urticating hairs are grown by tarantulas, and can reach a couple millimeters in length. They may be barbed, and have the potential to [pierce the skin](https://www.nytimes.com/2016/06/30/science/tarantula-colombia-kankuamo-marquezi.html) and cause serious problems for attackers. Allergic reactions have occurred in humans, and require immediate treatment The tarantula launches the hairs by rubbing some of its legs together, which releases a bundle of hairs; this increases the odds that at least one hair will hit the target. [This page has diagrams of several different hair types](http://arachnophiliac.info/burrow/urticating.htm) (copyrighted). Here's a photo of some on a Grammostola rosea tarantula, showing a "bald" patch where the hairs are grown (image in spoiler tags for arachnophobes!): > > [![enter image description here](https://i.stack.imgur.com/LTEh7.jpg)](https://i.stack.imgur.com/LTEh7.jpg) > > > Image courtesy of Wikipedia user Sarefo under [the Creative Commons Attribution-Share Alike 3.0 Unported license](https://creativecommons.org/licenses/by-sa/3.0/deed.en). > > > [Humans have been attacked](https://abcnews.go.com/Health/EyeHealthNews/tarantula-attack-pierces-owners-eyes/story?id=9458010) in this manner, causing eye damage. [Here's a video](https://www.youtube.com/watch?v=1cPxqjSG6HU) of what the ejection looks like, in real time. [Answer] The nettles of jellyfish are quite like projectiles being shot into the body of any animal touching it. But they are projectiles on a tiny scale. Other animals use spikes and quills as defence mechanism. The quills of porcupine and sea urchins are even designed to stick in the flesh of attackers, so they are already detachable. What is missing is a mechanism to launch them in the direction of an attacker. Muscles are probably not fast enouch for that purpose, so you need a lock mechanism that is under constant strain and can be released explosively. Think of it like a bow and arrow: you put constant tension on the string while aiming the arrow, only to release all the force at once by releasing your fingers. Although you excerted all this force with your own muscles, your arm cannot release this force fast enough to throw the arrow. In an animal you could attach tiny tendons to the quills that are connected to tiny muscles. Aggrevation causes the animal to tense up, straining the tendons. If the tension gets too much, the tendons rip, catapulting the quill straight from the skin. The disadvantage (and probably the reason why nature prefers liquid projectiles) is that quills, muscles and tendons take much time and energy to regrow. Reproducing a liquid requires much less time and resources, thereby offering higher chances of survival for the animal. [Answer] [Pellets](https://en.wikipedia.org/wiki/Pellet_(ornithology)) could be an option, mostly birds just cough them up as necessary and discard them but they could be spat at a predator/prey/intruder. Another option that I find personally disturbing, because of the creatures that use it on Earth, is hairs/skin grown spikes. [If you are arachnophobic don't follow this link.](https://en.wikipedia.org/wiki/Urticating_hair) Tarantulas have specialised hair like growths that they kick off their exoskeletons at predators, or anything else that intrudes on their territory, these are deliberately sharp and barbed so they stick in and irritate the skin, they also tend to get infected where they stay embedded, not sure if that's by design but there are ways to make it so it is. [Answer] I can present you thoughts, but not a clear answer: * The amount of matter exerted could mean a too big loss for the host body. If it's not worth and causes higher overall resource costs than what it yields on average, it's not feasible. * The projectile must be lethal. Meaning it needs sufficient power and venom. This may allow it to kill even greater prey. * The body structure has to be fit for that purpose while considering digestive systems. Plus it would be hard matter which may be clunky, slow down the creature, make it less flexible or disturb reproduction. * The creature may require unusually high intelligence, which is a rare good in the animal world, and may only be really feasible at extraordinary magnitudes, in addition to experience and inherent accuracy in order to aim and consider ballistics at distances in which its purpose would actually come to shine, plus consider ammunition. * What capabilities would remain if running out of "ammo"? Is that a death sentence, given the food input might be put on hold? If it's only for defensive purposes, for let's say a herbivore, the requirements and resource demands may be simply too high in order to compete well enough. [Answer] Not animals, and not for offense, but there are plants with projectile seeds, e.g. * [Jewelweed](https://en.wikipedia.org/wiki/Impatiens_capensis) ([video](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjDgNeF0O_cAhULJ8AKHbO4Dy0QwqsBMAB6BAgGEAQ&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D20zm18Lzt6g&usg=AOvVaw3I_-XnPncH2h59QQwoTRNZ)) * [Squirting/Exploding Cucumber](https://en.wikipedia.org/wiki/Ecballium) ([video: BBC Private Life of Plants](https://youtu.be/buZV0h4vfmQ?t=1m22s)) [Answer] Here's an evolutionary approach. Originally an egg-laying species could expel eggs as a way of distracting and escaping predators who would then feast on the egg. Over millennia this egg-expulsion could become faster and more powerful. The egg would be projected into the predator's face thus temporarily blinding it. Ultimately the shell would become thicker and thicker until solid eggs were produced and 'fired' at high velocity that would render the predator unconscious or injured. There would be two oviducts - one for creating viable eggs and the other for creating projectiles. [Answer] Cone Snails fire venom-filled, barbed harpoons at prey/threats! <https://en.wikipedia.org/wiki/Cone_snail#Harpoon_and_venoms> This is the closest real-life example I know of. [Answer] With venomous snakes, their teeth fold back into the mouth, and if they break they grow new ones. It could be that the creature has a similar mechanism, but that the "fangs" launch instead of just folding out to bite. If the projectile is in the mouth, it may be easier for the creature to aim? ]
[Question] [ I have an idea for a story set in the near future, with a character who breaks onto the global scene with a breakthrough advance in technology that makes him billions. My question is whether or not Ternary computing (as opposed to Binary) could be used as this breakthrough. I don't know much about it except that (apart from a few experimental computers) it never took off despite possibly being more power efficient or something (I don't understand a lot of what smart people do). Without the need to explain too much about how the technology works in the story, would it be plausible for Ternary logic to be the base of this tech revolution? [Answer] Walter Tevis wrote "The Man who fell to Earth" with the alien protagonist turning into a billionaire by releasing advanced technology on Earth, but this was done with a long term purpose: to build a spacecraft and bring his people from their planet to Earth. Tevis didn't dwell too much on the sorts of technology that were being introduced, since the story wasn't about the technology, per se, but rather the struggles of the being with the various temptations available on Earth, and how they eventually derail his plans. So focus on the story, unless the nature of the invention is the centerpiece of the plot. [Answer] Ternary itself, no. But some other revolutionary improvement that necessitates a ternary computer, yes. Possible candidates: Optical computing - high speed More accurately; low latency optical computing. We transmit data via optical cables today, but we still do all our processing electronically. Converting photons to electric signals, doing something clever to make useful electric signals, converting them to photons and sending them on their. This takes time. Not much, but it happens often enough to be an annoyance. Doing calculations on the photons themselves reduces the processing-delay. Optical computing - massively parallel One of the current big changes in computing today is the push from sequentially doing things (very quickly) to doing things simultaneously (even if it's slower). When you run a silicon circuit really quickly it'll struggle to switch on/off in time(1). Typically, you solve this by turning up the voltage to make them reach switch voltages faster, but this means they get hot and melt. But designing circuits that do many things at once is hard. We've been working on it for decades and we're still not very good at it. The first person to be good at it is going to be very rich indeed. A combination of the above - large-scale neural networks The discrete set {-1, 0, +1} looks a bit like the range [-1, +1]. That's the range of the [Sigmoid Function](http://en.wikipedia.org/wiki/Sigmoid_function). The Sigmoid is often used in artificial neural networks because of its similarities to the behaviour of real neurons. This doesn't automatically mean you have Artificial General Intelligences running about the place. This doesn't necessitate Skynet or the Robot Apocalypse. Consider that the software. What your character has developed is the hardware. Things that are more reasonable uses for a new, powerful, ANN; self-driving cars, market-trading software, better weather prediction (you'd be surprised how much money you could make by accurately predicting something that's assumed to be chaotic). (1) I'd provide a citation for this, but my Google-Fu is a bit lacking today. I learned this while at university. [Answer] No, not really. While it is possible to speculate a technological advance that would make ternary efficient and a problem domain where ternary is better than binary, the economics would still not make sense. While ternary increases information density, it does it in a way that is fairly easy to emulate in binary logic. Two bits actually have more information than a trit does. Dedicated binary hardware for emulating ternary is quite viable if demand exists. Which it so far has not. And it is difficult to imagine an implementation where ternary logic is not significantly more complex than the binary logic with same computational capacity. It is not impossible, but it is unlikely as most miniaturized (which you need to be competitive) components would be sensitive to non-linearities caused by the difference between -1 and +1 being larger than difference to 0. This adds overhead to the implementation similar to issues with analog computers with much lower gains than analog solutions gave. You'll note that analog computers are fairly rare as digital computers were easier to program and (usually) more reliable. People are running actual experiments with quantum computers and artificial neurons. These both have problem domains (or are widely believed to have anyway) where they can outperform binary computers with ease. And may map to some method of implementation directly. Quantum effects are part of nature and artificial neurons can be modelled after result from brain research. Either of those might make somebody rich. I started writing a list of possible breakthroughs, but that would go into idea generation, which is not what answers are really for. Just use something else. Unless it is story relevant you can just invent a "cool" marketing name for the invention and never explain what it was. All the characters already know what it is and none of them, possibly including the inventor, really understands it well enough to talk about it. Or maybe experience has taught him that if he tries to explain people suddenly have urgent business elsewhere. [Answer] I believe Ternary computing has been implemented in 1958 at Moscow State University. You can refer to this article: <https://en.wikipedia.org/wiki/Setun> However, this didn't really make a breakthrough I think. [Answer] > > History One early calculating machine, built by Thomas Fowler entirely > from wood in 1840, operated in balanced ternary. The first modern, > electronic ternary computer Setun was built in 1958 in the Soviet > Union at the Moscow State University by Nikolay Brusentsov, and it had > notable advantages over the binary computers which eventually replaced > it, such as lower electricity consumption and lower production cost. > In 1970 Brusentsov built an enhanced version of the computer, which he > called Setun-70. In the USA, the ternary computing emulator Ternac > working on a binary machine was developed in 1973. > > > Balanced ternary Main article: Balanced ternary Ternary computing is > commonly implemented in terms of balanced ternary, which uses the > three digits −1, 0, and +1. The negative value of any balanced ternary > digit can be obtained by replacing every + with a − and vice versa. It > is easy to subtract a number by inverting the + and − digits and then > using normal addition. Balanced ternary can express negative values as > easily as positive ones, without the need for a leading negative sign > as with decimal numbers. These advantages make some calculations more > efficient in ternary than binary. > > > "I often reflect that had the Ternary instead of the binary Notation > been adopted in the Infancy of Society, machines something like the > present would long ere this have been common, as the transition from > mental to mechanical calculation would have been so very obvious and > simple." —Thomas Fowler > > > The future: With the advent of mass-produced binary components for > computers, ternary computers have diminished to a small footnote in > the history of computing. However, ternary logic's elegance and > efficiency is predicted by Donald Knuth to bring them back into > development in the future.[5] One possible way this could happen is by > combining an optical computer with the ternary logic system.[6] A > ternary computer using fiber optics could use dark as 0 and two > orthogonal polarizations of light as 1 and −1. IBM also reports > infrequently on ternary computing topics (in its papers), but it is > not actively engaged in it.[citation needed] > > > The Josephson junction has been proposed as a balanced ternary memory > cell, using circulating superconducting currents, either clockwise, > counterclockwise, or off. "The advantages of the proposed memory > circuit are capability of high speed computation, low power > consumption and very simple construction with less number of elements > due to the ternary operation." > > > In 2009, a ternary quantum computer was proposed which thus uses > qutrits rather than qubits. When the number of basic states of quantum > element is d, it is called qudit. > > > As you can see from the Wikipedia article, qutrits have advantages. It is very plausible for ternary to be used if binary was not adopted. One of the reasons that ternary is not used today is that everything is based on and written in binary. ([Wikipedia article on Ternary Computing](http://en.wikipedia.org/wiki/Ternary_computer)) [Answer] No, the technology to produce ternary computers already exist, but there is no necessity. It is true that a ternary computer could be more fast with same number of transistors, but the performance gain cannot justify the high cost of production. You should also consider the power consume, if 2 binary transistor can consume less than 1 ternary there is no advantage. Think also that we need to redesign all architectures and rewrite all software, define new standards, migrate data (think to floating point from binary to ternary will be an hassle). Too expensive and no viable for the little performance gain. Think that now we continue to use x86\_64 architecture, it is a very complicated architecture designed to keep compability with the old 8086 CPU. Intel tried to propose a new clean x64 architecture, called Itanium but it has been a failure, the performance gain was unable to justify the the rewrite of all sotware, In my opinion the future will be 3D integrated circuits, once we will be able to 3d print processors and memory we will get a great increase of density performance and reduction of power consume, without breaking compabilities. Another future tech is quantum computing, in that case the performance gain (for some algorithms) is so big to justify the cost. [Answer] Ternary is the future. While we already had an example in 1958 Moscow with the "Setun" soviet ternary computer, we have yet to make it mainstream. The breakthrough will happen with new types of transistors that can do this adequately without errors. actually it may be quite messy to do this, but you can do ternary right this second with common transistors you can buy online or from electronic hardware store. Use npn transistors and flip their polarity. On both the collector and emitter inputs, you'd split each side with diodes so when the opposite N is active, the diode doesn't allow that corresponding output to go through it. When the OTHER side is powered, then the OTHER side's corresponding output's diode does the same thing. Like I said this is messy but it should work. Inaccurate and slow, but it should work. Transistors already have ternary capability. And because of the way they count, (by threes, not increments of one) they do both addition and subtraction all at once to get your value, and they do it by using far less logic gates to get the work done. So let's understand how ternary computers of the past counted. They used 0, +1 and -1 to represent their 3 values. They used ferrite blocks and diodes to do the job. However if we were to use actual transistors then 0 is of course the off position. +1 is the transistor in its on state going in one direction, and -1 is the transistor's polarity being switched to the OPPOSITE direction. To make things easier, we can write these three values as 0, 1 and T. 0 of course is OFF. 1 is +1 and T is -1. Here we go. Here is an example of how to count in ternary. The left most transistor is +9, the middle one is +3 and the second one is +1. Now when you flip these transistors, of course it's easy to figure out what their values are :) -9, -3 and -1. 000 Ok all 3 transistors are in the off state. This is the value "ONE" 001 This is "TWO" 01T Ok so the middle transistor is at "1". That means it's +3. The right most transistor is T or -1. That means it's minus one. 3 minus 1 = 2. 1T for short. (but don't forget their positions. 01T is more obvious but 1T is short) 10T That's 8! +9 minus 1 equals 8! Eight in binary is 1000, making it more expensive and energy consuming. Of course this particular number isn't more energy efficient in ternary than it is in binary, but most numbers are in fact less energy efficient. Not to mention the complication of circuitry in binary adding to the cost of the CPU. The amount of transistors in a common GPU is like 5 billion these days. Probably more. It's ridiculous and it's not going to get cheaper or more energy efficient any time soon. ]
[Question] [ Many fictional worlds have their civilizations (usually the bad guys) ride some sort of carnivorous animal, usually something like a wolf or a creodont. Think something like the Wargs from Lord of the Rings, though this goes as far back as the Thracian Mares. It has often been pointed out these kinds of mounts are very inefficient because it costs a lot more to feed an animal meat than keep an animal with a simpler, more cost-efficient diet like grass. We all know the real reason why these characters are riding carnivorous animals: because it's cool. But how could this be justified in-universe? Assume for a moment a civilization has to make use of a carnivorous, vaguely creodont-like mammal as a mount or beast of burden like the Lord of the Rings Wargs. Say this is the only easily tamable animal that civilization has access to that can bear the rider's weight or something, with the other animals in the environment either being too small, too aggressive, not having the right body shape to bear loads, etc. What would be the most effective way to feed these animals? It is okay if these animals are somewhat omnivorous or can be fed non-animal protein. I am more trying to figure out how to preserve the image of someone riding a carnivorous, wolf-like beast that can eat their targets if given a chance. Mostly what I was wondering if there is some kind of protein rich food or way of storing animal protein that would make it (relatively) cost-efficient to feed these animals, assuming these animals are technically omnivores but are still primarily predators. [Answer] ## They fill the role of Horse, Dog, and Cat in one We humans started adopting cats because without them our towns get over-run by vermin that eat our food and spread diseases. But orcs don't worry so much about wee little grain hungry rats getting into their food supplies because everyone knows grains are not the staple food item of the Orc anyway. Orc's staple crop is actually the mushroom, and their biggest pest animal is the wild pig. Wild pigs can smell mushrooms from miles away and are drawn to orc camps like moths to a flame... always trying to sneak into the mushroom fields for a free feast, and cats are just too darn small to do anything about it. So, orcs domesticated Wargs instead. The Orcs let them roam the camps and farms at night hunting for pigs the same way that we rely on cats for mice. This makes these large alpha predators as self-sufficient as a horse allowed to graze, while also filling a symbiotic relationship with the Orcs by controlling local pig populations. We humans also adopted dogs because they make great guard animals. They warn us of danger while we sleep and can put up a pretty good fight while we stumble around in the dark looking for a weapon. Since your Wargs are already patrolling the camp site looking for pigs, they also make good guard animals like a dog. The fact that the Wargs are so big also naturally makes them a good substitute for horses. Sure, the Orcs could try owning both horses and wargs, but A: it's a bit of a waste of resources to own a horse when you already have a warg, and B: it's hard to keep the wargs from eating your horses. So, when the Orcs have to choose between owning a Warg and a horse, the Warg just makes more sense. Instead of domesticating 3 separate animals, the Warg is like the Swiss-army knife of domestic animals. So sure, during a long campaign, you may need to pack plenty of meat since the Wargs won't have time to hunt, but in day-to-day life, they pull thier weight so well that it's totally worth it. [Answer] It's expensive but cool, therefore it is reserved for the elite. If only few can afford to have them, the beasts become even more precious status symbols. If there is a whole band of warriors riding them, then it means the group is in a league of its own. They are willing to make the extra effort to maintain the image, and, typically, it means that they are making the effort to exploit others. [Answer] 1: the Husky route. Imagine having a large bunch of Huskies strapped in front of your sled and having to feed all of them on your trip. That’s going to be a lot of food on your sled just for them. So the original solution was to just set them loose after the day’s travel and the Huskies would hunt and eat everything they could find and catch, then return to the camp. As long as your area’s are expansive enough and with enough prey animals capable of living there, you can have a group of carnivorous mounts. 2: hunt and preserve. Your mounts can eat only so much, but they can’t preserve food. You can. Training them to bring leftovers, or even to hunt specifically to bring back for the owners to preserve or eat, would be a solid tactic in case not enough food can be gathered at the next stop. 3: Nuts and other high-proteïne food. Most hunter animals can absolutely eat them, wolves and Bears being a good example. Nuts are relatively easy to keep fresh as long as you keep them dry and perhaps roast them. 4: insect farms. Most carnivores can eat various insects. Some insects like grasshoppers could be cultivated in dark boxes where you just throw in plant matter. This would just be a supplement unless you bring ridiculous amounts of these boxes to grow insects. Although this could be simply be part of your non-combattant group that follows the army. Ways to make it easier to have such animals: * hibernate on command. Some carnivorous animals can hibernate, like bears. If your animals can pack away a ton of food and hibernate afterwards you can maintain a much larger population during peacetime or when your area isn’t close to the frontline at that point. Just wake them up in advance, animals that hibernate need to alter their hormones to get back to normal functioning. * That’s it, couldn’t think of more options right now. [Answer] # Temporary War Form Like the salmon or butterfly, these mounts are normally unremarkable, but can transform temporarily into something better suited for war. During war they eat enemy soldiers. [![enter image description here](https://i.stack.imgur.com/hVoQ6.png)](https://i.stack.imgur.com/hVoQ6.png) --- When the Westerners attacked they rode these big scary pig monsters. [![enter image description here](https://i.stack.imgur.com/nQcPn.jpg)](https://i.stack.imgur.com/nQcPn.jpg) They fed them with our fallen comrades. It was demoralizing. We named the mounts the Demoralizing Pigs. Once we realised the pigs only ate meat, we used scorched earth tactics to starve them. With no fresh meat, the Demoralizing Pigs rebelled against their masters and we mopped up the rest. Then we made our own invasion. We were prepared to fight more Demoralizing Pigs (we made special long sticks). But the only pigs we found in the West looked like this. [![enter image description here](https://i.stack.imgur.com/q23uW.jpg)](https://i.stack.imgur.com/q23uW.jpg) Not a Demoralizing Pig in sight! In any case we took all the pigs and brought them home. They taste nice. All was well until one of them got loose in a graveyard. It dug up Auntie May and feasted on her corpse. Two weeks later that pig mutated into a Demoralizing Pig. It turns out the Demoralizing form is a short lived war form. The pigs are raised and trained as normal pigs. Only when it is time for war are they fed human flesh. This mutates them so they become big and scary. But they also need flesh to live in this form. Good thing we are at war! [Answer] Plenty of Prisoners Yeah, that's right, we going there. Trial by Jury? Nope. Mandatory Appeals? Nope. Hanging Judges who sentence death at the slightest infraction? Yep. Sentences carried out almost immediately? Yep. That's how you keep them fed - by feeding anyone unfortunate enough to be convicted of a capital crime to them. There's lots of crime and the Justice system is much more swift (if not more error prone - but everyone is a sinner anyways, so...) If you throw in Vagrancy as a crime as well, then you get to kill two problems with one animal - Law and order is maintained and there's no pesky beggars in the street. Win Win! In addition, Hunting trips for non-game animals (think other, wild predators) that provide sport for the nobility, but also a steady supply of fresh meat for the beasts - and you've pretty much got yourself sorted. [Answer] Meat eating animals can ingest a lot of calories and thus be more powerful. They also need to eat less as meat is energy dense. An elephant eats 150Kg a day, which is a huge mass of food. Logistically it will be much easier to transport meat than a huge volume of grass, even if the food costs more. Taking into account the cost of transporting food, it likely will not be more expensive to supply. Bonus, you can let them eat the bodies of the enemies you have conquered. [Answer] Herds of goats I have crunched a whole heap of numbers for a comparable problem in a story I have almost finished and there is no good solution. The best I could come up with is a significant logistics "tail" for the cavalary consisting of herds of goats that are progressively slaughtered and replenished - goats being the preferred prey animal because they can eat almost anything, with the bonus that there's plenty of goat hair and hide produced for other purposes. (For a consistent society, have goat leather and textiles woven from goat hair as cheap and ubiquitous because the cavalry consume so many goats.) One of the practical effects of carnivorous mounts in cavalry, as noted elsewhere, is that the cavalry will be a small, elite group because it is simply not feasible to sustain a large force. There will also be a temptation to use it for something all the time because it is just too expensive to be left idle. Consequence for society is that there will be a surplus of mounted couriers, because it is a simple and less dangerous activity compared to the alternative. Idle cavalry will need to be exceedingly rich - with individual riders controlling large estates with herds of goats to feed their mounts - or mercenaries/bandits constantly undertaking high-paying (= high risk) jobs to keep their mounts fed. (An alternative is to have large free range areas where the mounts can go hunting, but this tends to require 3-10 times more area to feed the same number of mounts as can be achieved by goat herding. If you do go the free-range concept, the owners of the cavalry will definitely exterminate any predators competing with their mounts for prey animals.) Along similar lines, deployments of cavalry will be small and/or for short, sharp actions. Noting that the majority of military actions in ancient and medieval times were sieges rather than battles, the implications should be obvious - cavalry cannot afford to be caught in a besieged city/town/castle or the mounts will quickly run out of food. By the same token, it would require a major logistics effort to feed a cavalry force supporting a siege. [Answer] You have a few options. First remember almost nothing can eat only meat, hypercarnivores are very rare. 1. If they are more like omnivores, AKA wolves and creodonts, you go with a lot of leftovers. You feed them the leftovers and carcasses of meat animals, mixed with grain and vegetables, think pigs or dogs. 2. If they really are hypercarnivores, go for fish. Fish are a lot more efficient than most meat animals you can farm. as a bonus many farmed fish can be fed damn near anything. If you are going premodern then you can get massive fish hauls, prior to modern times net fishing could yield so much fish and shellfish would be used as cheap fertilizer. [Answer] What are your characters eating? Chances are, you can feed your mounts the same way you feed your characters. When your characters go hunting, they butcher their kill and eat the meat. They're left with a lot of less-palatable [offal](https://en.wikipedia.org/wiki/Offal) like the heart, liver, and other organs. Some cultures like the Scottish developed [limited use](https://en.wikipedia.org/wiki/Haggis) for these, but most cultures discard them as unpalatable or even taboo. Your culture does not eat this offal for themselves, but instead uses it to feed their mounts. You could even have the act of sharing your kill with your mount be a sort of bonding experience that approximates the relationship these animals would have with their kin. When you're on the move and need something you can store for extended periods and transport with you, jerky is easy to make and will keep for a long time. That wouldn't be your primary food source, but you'd use it as a protein supplement to whatever else you're feeding them (grass, scavenged produce, etc). I don't know what your technology level is, but you could also mirror the way we produce [dog food](https://en.wikipedia.org/wiki/Dog_food#History). Mix meat with filler like rice or beans, grind it into a paste, and either can it or make kibble by extruding and baking it. [Answer] ## It's gonna be hard to explain Two problems. One, it doesn't make sense for these to be the only animals able to support their weight ─ the largest animals in any ecosystem will always be the herbivores. Two, it doesn't seem like there's any reason for this aside from it simply being cool. And if it's for speed, remember that predators and prey are in an \arms race\ ─ neither will be faster than the other for too long (at least in general). ## But if you really want an answer... But if the people riding them are small (e.g. gnomes, halflings/hobbits, dwarves etc), it would be plausible that they could be small omnivorous mounts, too ─ wolf-esque. [Answer] Horses have been known to eat meat. Some societies feed their horses meat on a regular basis. There are stories of man-hunting horses. So, we don't need to invent a new animal. Horses fit the bill already. <https://www.nationalequine.org/feeding/horses-eat-meat/> [Answer] # Herding rideable carnivore As you note, it is harder to feed carnivorous mounts. What makes this even worse is that such animals require more of basically everything the bigger they get. Notably hunting grounds and meat. We can see this well with two examples. Wolves and tigers. Wolves aren't the largest by far, but because they are often in groups they still need a lot of space to get enough food. For tigers it is much the same, though they are much more solitary. They have huge hunting grounds and tolerate few others. This is a tactic to still have enough food. A rideable carnivorous mount is near certainly solitary, unsocial and cannot be tamed because of it's size and requirements to survive. Unless it can make due in a different way. For this we can look at one other big predator. Humans. Most humans used to roam huge swathes of land to hunt and gather enough food. This was reduced by insane amounts by two inventions. Husbandry and farming. Your carnivorous mount can do much the same thing. It can start herding animals to gain enough food. This is best done in a group, laying the groundwork for an animal that can be tamed. They protect the herd from harm, making sure the herd prospers as they eat some of them. ## Conclusion Your huge carnivorous mounts come with a herd attached. You tame the group, which will lead the herd to wherever. It's own travelling and replenishing food source, much like camp followers with an army in many ways. [Answer] [![Cat that looks a lot like Puss](https://i.stack.imgur.com/gClUQ.png)](https://i.stack.imgur.com/gClUQ.png) ## Cat kibble You can't ride my cat Puss. She is only a normal (small, actually, she was a runt) sized cat. But what does she have in common with a carnovorous mount? She can subsist\* on kibble that is mostly grains and vegetable protein with a little meat mixed in, if necessary. Providing there's enough protein and it tastes like meat, mounts will eat it and live. The amount of meat needed is minimised. Obviously, the mounts are rewarded after battle with fresh meat, which greatly increases aggression in anticipation. Puss becomes like a scale version of a lion, roaring at our other cats which are far larger than her when there is fresh meat to be had. The sonic expressions of aggression out of our tiny sweetie have to be seen to be believed. * We don't feed her much kibble; she prefers wet food and, of course, real meat. [Answer] Sledge dogs can be fed sledge dogs, as Roald Amundsen demonstrated on his trip to the South Pole. In normal circumstances, I guess sledge dogs eat seafood like their masters. Walrus, whale, fish. Breeding exceptionally large dogs would enable small people to ride them. [Answer] ## Rabbit Makes a Fine Meal Rabbit meat can make for a pretty good supplemental food source for dogs, and it could potentially be used for your rideable carnivores as well. Perhaps your people have developed a breed of extra large meat rabbit. And they multiply very quickly as well, so it’s a pretty sustainable meat source. [Answer] The mount is an apex predator at the top of a food chain, only "humans" kill them, and only if they use tools, traps and cooperate. The animal is considerably smart. It learned to avoid humans who don't even taste all that well for all the troubles. Humans generally avoided messing with them too because it just didn't worth it. Until they found out that the animals really like alcohol (or specific kind of alcohol or something else they can't find/make themselves). The domestication started. A human finds an animal and gives it some booze, it wants more and follows. Being smart, it forms something like a temporary bond and works for booze. The animals hunt for food, humans give them time for it or get eaten. With civilization being somewhat primitive hunting grounds are never too far. The animal is an excellent hunter and understands that people would get upset if it eats their precious cows and sheep. There are significant benefits in keeping a single animal long term - both parties learn quirks of each other. Abusing the mount is rather dangerous, but it may accept some hardship if it knows the rider well enough and expects to be rewarded properly. While booze is not exactly cheap, it still beats keeping a horse which needs lots of food, care and protection. Only losers ride horses, all the cool kids have raptors. ]
[Question] [ In my novel, I was planning to have the palace/citadel type place located inside a mountain- so like a sort of cave type thing, but on a bigger scale. There would be decoration around the entrance of the palace, and staircases leading up to it, but the palace itself would be built into the actual mountainside. The people in my story aren't super advanced with technology, so I'm not entirely sure if this is extending past their capabilities or not. And also whether this is actually possible by any means- for instance would the mountain have to be made from hard rock for it to sustain its shape? Any sort of advice/ideas on whether this is possible or how I would have to adapt things to make it possible would be much appreciated!! Thanks! [Answer] If you haven't heard of [Petra](https://en.wikipedia.org/wiki/Petra) before, you're probably in for a treat. Here's a nice photo of [Al-Khazneh](https://en.wikipedia.org/wiki/Al-Khazneh), the treasury: [![An image of the entrace to the treasury of Petra, taken from the cliffs above](https://i.stack.imgur.com/uMjeq.jpg)](https://i.stack.imgur.com/uMjeq.jpg) (image credit: [Elias Rovielo](https://www.flickr.com/photos/eliasroviello/31579875098/in/pool-historyantiquities)) Petra is a city, with large portions carved into desert sandstone. It was built around the second century BC, so you don't need super fancy modern technology to accomplish this sort of thing. The insides of the buildings they'd carved into cliff faces were somewhat plain and simple compared to the amazing exteriors, but that's not to say that they had to be. For something a little more modern, consider the rock-cut temples at the [Ellora caves](https://en.wikipedia.org/wiki/Ellora_Caves). Still over a thousand years old, some bits date back to the 7th century. [![Kailasanatha temple interior](https://i.stack.imgur.com/29K8p.png)](https://i.stack.imgur.com/29K8p.png) (image credit: [Akshay Prakash](https://en.wikipedia.org/wiki/File:The_Kaila%C5%9Ba_temple,_Cave_16.jpg)) The Kailasa temple was apparently carved from a single contiguous chunk of rock in a hillside, no additional masonry: [![Kailasa temple exterior](https://i.stack.imgur.com/m0GbX.png)](https://i.stack.imgur.com/m0GbX.png) (image credit: [Y. Shishido](https://en.wikipedia.org/wiki/File:Ellora_cave16_001.jpg)) If your people have access to friendly geology with decent rock that's not super hard, and access to good metal tools, they're probably good to go. It'll take a lot of work by a lot of people over and extended period of time. Remember that a lot of ancient massive works were built by huge numbers of slaves, often taken in war. Free (or at least, free-ish) people can and have accomplished similar large scale constructions, but have a think about who will be doing the hard work, why they're doing it, under what conditions, and how that fits into your history. [Answer] It has been done. Often enough that it has a name. Use a [cave](https://en.wikipedia.org/wiki/Cave_castle). Notice that it was chiefly done for fortification with other buildings being outside. Then castles had many more functions in times of old. You may want to still situate other functions outside, such as the attached slaughterhouse. Putting everything inside is either a sign they face grave danger, or grand conspicuous consumption. [Answer] In addition to the answer by Mary, consider * [Petra](https://en.wikipedia.org/wiki/Petra) * [Kaymakli](https://en.wikipedia.org/wiki/Kaymakli_Underground_City) * The underground part of the [Gibraltar](https://en.wikipedia.org/wiki/Fortifications_of_Gibraltar#British_period) fortifications. But there are different requirements for a fortress, a citadel, and a palace. Meanings change over time and with context, but a citadel tends to be either a fortress to overwatch a city or similar resource, or the inner part of a fortress. A fortress may or may not be larger than what one thinks when one hears citadel. Generally, people live in a palace, often rather well, they also live in a fortress, but they retreat into a citadel. Especially with low technology, there could be problems with air, with light, with smoke from light sources and cooking, and with waste disposal. One way to provide air without modern pumps was to light a fire that would suck air from the cave and ventilate smoke through a chimney, but that would require round-the-clock attention. I'm aware of it being used by sappers in sieges, not sure about permanent dwellings. Damp and cold could also be problems. So it is probably possible, even in relatively soft rock, but it takes a lot of effort to make it a palace fit for a king or queen. [Answer] A bit of a frame challenge, but this may be close to what you're going for but allows more building space: build your palace in/on a cliff. [![Dogon cliff dwelling in Mali](https://i.stack.imgur.com/CGWps.jpg)](https://i.stack.imgur.com/CGWps.jpg) A real world example are the Dogon villages. Due to persecution of the Dogon people they highly prioritised the defendability of their houses and storages. A readily available options was found in the Bandiagara escarpment, a sandstone cliff next to sand flats. Villages were built in overhangs in the cliff face. There is a path leading up to the village, but it is well hidden - one anthropologist wanting to visit was even hoisted up in a wooden basket. [Answer] Not sure what is the threshold for "super advanced with technology," but the [Cheyenne Mountain NORAD base](https://en.wikipedia.org/wiki/Cheyenne_Mountain_Complex) was completed with 1960s technology. ]
[Question] [ I want a character to invent the codex (that is, modern-shape books) in Ancient Egypt, which means that the primary writing material is papyrus. However, most book binding processes involve sections of folded sheets glued or sewn together. Also, the quickest demonstration of the advantage of a codex over a scroll is to take the scroll and fold it concertina-wise to show how you can easily access parts from different ends of the document. Therefore, my question is this: Does anyone have a good source or experience whether a sheet of papyrus can be creased as tightly as paper can, or does it break? [Answer] # Reality Check Although you've already gotten basic answers, I'll address the specifics of your question. As others have stated, yes papyrus can be "folded" and yes, papyrus can be "folded" into books. Ancient codices do in fact exist. However, that's not what you asked. Your question is can papyrus be creased as tightly as paper can, or does it break? The answer(s) are no it can't and yes it will break. Here at the Practical Geopoetry Foundation, we have obtained a fresh, unfolded papyrus scroll, fresh from the antiquities market of old Cairo: [![https://i.postimg.cc/P5DtdBJg/papyrus-1.jpg](https://i.stack.imgur.com/G6mQT.jpg)](https://i.stack.imgur.com/G6mQT.jpg) A detail of the area to be folded, showing the large strands of fibre: [![enter image description here](https://i.stack.imgur.com/JJv9S.jpg)](https://i.stack.imgur.com/JJv9S.jpg) The back side of the same region before folding: [![enter image description here](https://i.stack.imgur.com/zd2Pp.jpg)](https://i.stack.imgur.com/zd2Pp.jpg) The fold after creasing and pressing: [![enter image description here](https://i.stack.imgur.com/Mhx3Y.jpg)](https://i.stack.imgur.com/Mhx3Y.jpg) As you can see, the papyrus is folded. During the process, one can hear the snapping of the vertical fibres and feel the slightly jagged edge where the layer separated. Also, you can see clearly that the papyrus fold is not as tight as that obtainable with either rag or wood pulp paper. Paper folds much tighter: [![enter image description here](https://i.stack.imgur.com/fwyuM.jpg)](https://i.stack.imgur.com/fwyuM.jpg) If you've never worked with papyrus, it is a rather thick, quite heavy duty material. It's made by pasting layers of plant fibre together, horizontal over vertical. It's an okay writing surface, though not as nice and smooth as vellum or paper. The thick fibres make it difficult, though not impossible to fold. The material will eventually crumble along the fold. Conclusion Of course, your character can invent the codex at any time papyrus was available. She just won't be able to get a neat & tightly folded book without actually damaging the material in the process. [Answer] Papyrus can be folded like paper. Ancient jewish communities would [write documents in papyrus, then they would roll the papyrus, flatten it, and finally fold it:](http://www.bible.ca/manuscripts/bible-manuscripts-archeology-Elephantine-papyrus-Egypt-Aswan-Syene-Darius-persian-Jewish-colony-temple-burned-Bagohi-Sanballat-passover-wine-fortress-Ezek29-10-495-399BC.htm) > > (...) Papyrus legal scrolls are rolled, flattened, folded in thirds the bound with a knotted string then sealed with two pieces (...) > > > (...) Unlike contracts which were rolled up and folded in thirds, letters were rolled up and folded in half, addressed on one of the exposed bands with the name of the sender and the recipient (and sometimes the destination [TAD A2.1–7]), and then tied and sealed just like the contracts." (ABD, Elephantine Papyri) > > > The site in the link also has this image: ![Folded papyrus](https://i.stack.imgur.com/uGpJd.jpg) As you can see, some folded papyrus documents have survived the ages well-preserved. The elephantine ones are from a handful centuries before Christ. [Answer] ## Papyrus can be fold to form a codex, and it was The reason you give (non-linear reading) was the main reason to use codex rather than scrolls, and a particular book make the codex format known: The Bible One example that comes to my mind is the [Bodmer VIII Papyrus](https://www.facsimilefinder.com/facsimiles/bodmer-viii-papyrus-epistles-of-st-peter-facsimile) [![papyrus](https://i.stack.imgur.com/1nV5L.jpg)](https://i.stack.imgur.com/1nV5L.jpg) > > 18 thick folios contain the text of the Epistles attributed to St. Peter and constitute the final part of an original codex made of papyrus that in its complete version should have had at least 180 pages as suggested by Michel Testuz. > > > However, this may depend on the period events occurred. As I said, Codex become popular with the raise of christianity, but the Volumen was much more common before Christ [Answer] # Have you considered a binder-format codex? The problem you have is that papyrus is harder to fold. Not impossible, but harder. What if you used a system that doesn't require folding? There are 2 main ways to bind individual pages where you don't need to fold the pages themselves: the Atoma variation: [![enter image description here](https://i.stack.imgur.com/Zsam8.jpg)](https://i.stack.imgur.com/Zsam8.jpg) And the ring variation: [![enter image description here](https://i.stack.imgur.com/zaUdL.jpg)](https://i.stack.imgur.com/zaUdL.jpg) Both of these variations to me appear like it's possible to make them with materials from the Ancient Egyptian timeline. [Answer] @Nzall has a good idea in having loose pages bound, rather than using folding, but a more authentic earlier style would be sewing the pages together. While tightly sewn papyrus pages would still need some folding to "open" the pages where required, a loosely sewn binding could mimic a metal ring or spiral binding to allow careful turning of the pages to allow them to lie flat. While most bindings sew through folded pages, this is not a strict requirement. Your protagonist could also add heavier fabric covers to help protect the codex while it is stored. ]
[Question] [ It is a post apocalyptic world, all government systems have broken down, approx 95% of the worlds population is gone and the few survivors left are beginning to trade with each other. I need a currency, and I am thinking of giving every thing a calorie value. Eg. 500 calories = 1.2kg carrots = 200g beef steak = 3 cups of milk A day of hard labour would be worth 3000 calories (eg. 2kg beef steak and 6 cups of milk) How do I value non-food items? I feel these are not as valuable as there is so much lying around (at the moment) - the valuable things are food and skills (eg daily labour). What are the problems with this sort of currency? Thanks [Answer] There's a few tweaks that your society would make rather rapidly. First and foremost, they would choose to standardize on a long-lasting caloric source like grains. If I already have dinner tonight, and you offer me 2 steaks in exchange for my work, I'm going to say no. Why? I don't need steaks and they spoil. Spoiled food is wasted wages. If you offer me two steaks, I'm going to try to trade them in for a grain as soon as possible. Grain is an excellent store of calories in the long term. Do this for a few days, and your employer will quickly realize that they can cut the middle man out and pay you in grain directly! I'd say it'd take about 5 days for this transition to occur! This transition will also save you from the other issue: scurvy. Well, scurvy and dozens of similar diseases brought on by malnutrition. We need a lot more than just calories to survive. Spinach has a mighty 79 calories per bunch, contrasted with potatoes which come in around 160 calories per potato. It's a lot easier to grow a potato than a bunch of spinach, so farmers will quickly start growing only potatoes. However, spinach has loads of nutrients you need that aren't in potatoes. Your entire post-apocalyptic society could starve while being well fed on potatoes! If you have standardized on grain, rather than calories, the value of spinach is going to be much higher than its mere caloric value suggests. You have to get away from measuring worth in calories before anyone will grow spinach. If the standard is calories of grain, rather than calories in general, there's room for the value of spinach to grow beyond the value of its calories. Speaking of which, another reality is that your system will result in 0 meat. No steaks. Why? Because their value in calories is far far below the value in calories you had to put into the animal. In most cases it's at least a 10 fold difference in calories going into the animal to meat harvested, and its typically higher. Anyone trying to feed cattle would quickly realize that they're driving themselves bankrupt with such an inefficient industry. There's a reason why, when you go to the store, a 200g steak costs quite a lot more than 3 cups of milk! This also avoids the reality that caloric content is remarkably hard to measure short of burning the food to see what it had in it. Caloric references like we have today are really just intended to be a reference point. Your actual caloric intake may be markedly different depending on many factors. Edit: To respond to several comments, I'm not advocating a purely vegetarian diet, especially not one consisting just of potatoes and spinach. I'm merely pointing out that the caloric value of these foods is not their only source of value, and if the prices were fixed according to their caloric value, many source of food would simply not be used. Instead, I would expect the currency to transfer from calories to some other unit of value which is more capable of expressing the value of different food products. [Answer] A wage system requires a functioning market. If 95% of the population was wiped away, it is quite likely that you won't have a functioning market. People will work for food, and this is going to be far from standardised. It also means that there is going to be no market for much things besides food and shelter (as implied, btw, in your hypothetical example of 1 work day = 2 steaks + six glasses of milk): you are going to eat your salary, which means no provision for buying cell phones / automobiles / wheelbarrows / knives / clothes. We are talking of a population similar to that of 500 AD. At such level of social decay, any currency, or "currency", will be local, not global or even "national" in the sense we understand "nations" today. And quite probably the whole economy will be replaced by a land-based system of production: if anyone can retain legitimate "property" of a stretch of land, they won't pay salaries for workers: they will allow workers to use the land for subsistence, and collect whatever surpasses subsistence levels as rent. Think feudalism or similar forms of landlordism. Excedents will be low, industry impossible, artisanship quite limited, commerce quite rare and mostly in the form of barter. [Answer] Food isn't currency, unless it keeps nearly forever and generally won't be used as food at that point. Food is a TRADE item. Here is a lovely link to a story listing [many food items](https://www.cryptocoinsnews.com/12-types-currency-throughout-history-eat-drink-smoke/) used as currency. As you can see, they have something in common. They don't spoil. You asked for flaws in your system, here's a list. * Food is only valuable if you are hungry or you don't have any food. * If food spoils and you don't get to eat it, food LOSES value, it does not retain it. * You're talking caloric value in an APOCALYPSE? In order to measure that, the process involves burning the food in a controlled environment. For a regular person, there is not actually a way to measure that accurately. Sure, it's on the back of food, but that's for a limited time only. * There's way more to nutrition than calories. We need all kinds of stuff to survive. See Cort Ammon's answer here for more detail. * I see that you're talking early apocalypse here, because you're talking about other stuff not being as valuable because it's "lying around." It is counterintuitive to think that there's been time to set up an intricate calorie economy, but not enough time for people to grab everything they could get their hands on. Stuff like that has to be enforced, which means a government. Requirements for currency. * There's a finite amount at any given time. There isn't too much or too little of it. * It doesn't rot or wear out. Best if it CAN get wet without being destroyed. * Portable, lightweight. * Difficult to cheapen, thin, or counterfeit. * Possibly fungible. That is, the value of the currency does not depend on weight or measurement. You might have different denominations or sizes, but they tend to be static enough that they don't have to be measured to know the value. Not true in the case of salt or tea, but as it was used more often, things like that would be compressed into bricks that are of uniform size and shape so that one doesn't have to have equipment to know the value of the money. Resources you might want to look to: Two Years Before the Mast is a great book, but the feature you do want to look at is what the currency in it actually was. Before California was adequately settled, they used hides as currency. Through out history, the pelts of animals, be they snake, squirrel, cattle, whatever, have been used as currency in places with either low cash or none at all. Look at [Cowrie shells](https://en.wikipedia.org/wiki/Shell_money). Blankets, because they take time and resources to make. Actual livestock. Weapons. Specifically, [knives](http://encyclopedia-of-money.blogspot.com/2010/01/chinese-knife-money.html) because of portability. In Fallout, it's bottle caps. They are everywhere, but, they are in limited quantity. Any object that fits the criteria can be your currency.NOTE: Don't ever use Fallout as you model for "stuff laying around" 200-300 years later, because most of that stuff and the skeletons supposedly lying around exposed, outdoors since the blast, actually would be disintegrated. Highly recommend the series "Life After People" if you want to see how quickly stuff breaks down. [Answer] The only problem I could see with your calorie system, is that you're implementing it in a post apocalyptic world... Basically I can picture people squabbling over the true vale of their foodstuffs and it's also easy to guess that in a post apocalyptic world where food and resources may be scarce that people would be inclined to barter and haggle based on perceived need. People who are starving are likely going to be willing to pay a little extra, call it gouging, but it's an unfortunate reallity. Without a governing body, or people who are really inclined to work cooperatively, establishing standard values for goods is going to be really difficult. [Answer] Medieval Japan used the system you are looking for. The currency unit was the "koku" defined as: "The standard unit of measure was the koku, the amount of rice needed to feed one person for one year." <https://en.wikipedia.org/wiki/Koban_(coin)> There were also gold coins used for more valuable items (properties/animals/weapons/luxury items etc...) by the feudal elite. Paying everyting in rice bags was too impractical for high value items. The value of a gold coin was initially set to 1 koku but as time passed and lords debased their currency, the value changed. Later, silver and brass coins were introduced as trade flourished and commoners used them too. The common currency should be something that has intrinsec value,can be consumed even if there is no one to trade it with and doesn't decay with time (rice/grains). For more valuable transaction you want something Rare that cannot be duplicated or counterfeit easily (rare metal/minreal). I can imagine the same system emerging in a post apocalyptic world. Food,bullets,tabacoo could be used as a commoners currency and some rare metal/mineral could be used for bigger transactions. [Answer] The word "salary" (wage) comes from salt in latin. This is because some societies paid their workers in salt. Salt is an important commodity to make another very important food : salty meat. Lacking refrigeration infrastructure meant that the only long term way to store meat (meat quickly spoils) is to salt it (there are other more complex ways like smoking it). Meat is a basic need due to the protein uptake needed too sustain human life (our brains and muscles demand a lot of protein to repair and keep alive). So, in a post apocalyptic world, salt might very well become an important commodity (or salted meat) and a reference of price. The only drawback is that the ancients did not produce salt from seawater due to lack of knowledge, but we nowadays can produce it (unless too far from sea) from sea water, wich is something way cheaper than the salt used in the past that came from mining operations. tl;dr Use salt in areas far away from sea. [Answer] At first, non-perishable calories are probably the only thing starving people will trade for, but that won't last long, once people have a surplus to trade. I suspect that the initial unit would work out to one adult meal (or perhaps a day's food, instead?) Dry rice, corn or especially beans (for the extra protein), since those can be eaten without being finely milled. Most people won't have access to a working mill, and unmilled wheat is not easy to digest! I expect that the relative value of other items would vary by circumstances. But dry grain or beans have a problem, they're not very value dense, relative to what an adult can carry. How many day's food could you carry, of dry corn and beans? (Milled flour is even worse, since it's bulky as well.) But if you want to carry or trade more stored value than a week or two's calories (and still be able to eat), you'd want to hold your tradable-value in something more value per unit mass, some agreed-value, hard-to-forge tokens, like coins. In my post-apocalypse world, one group overstrikes certain coins, issuing them for local trade. Since they have about the only tools for that, it's a workable solution, at least short term. [Answer] Your currency is your trade items and supply and demand. Using a food as currency in such a World will lead to strife very quickly. Trying to store any large amount without protection is going to lead to strife. Control of the sources of this will lead to strife. You hold what you can protect, if you hold too much someone else will want to take it from you and everyone is a bit nuts and probably heavily armed after going through an apocalypse. Swapping resources between primitives was accomplished a few ways. Following is three commonish ones. GIFTS:- a group would go (in numbers) singing (so the others know they have no bad intentions trying to conceal themselves. And gift the other group a bunch of resources they took with them, everyone has a meal meets some new ladies and leaves. Then in time the other group amasses some surplus and reciprocates. TRADERS:- travel around swapping resources for other resources and taking them to places which are short on a particular resource. This is driven by supply and demand basically. The traders could be group sanctioned or group owned instead just trading within certain groups where they have treaties of some kind. RAIDING:- a belligerent group attacks another and takes what it wants if it can get away with it. TRIBUTE:- a group basically taxes others around it, either because it is the most powerful or because it has some other advantage such as bloodline. This is very common both large scale and small within groups themselves. The tribute comes in the form of freely given gifts in outward appearance, but it's really essentially tribute in that there will be repercussions if they stop freely giving these gifts out of the kindness of their hearts.. Between nominally friendly groups the first is best, and it was used even during wars in some places. It's drawback is it's basically a trust relationship, although there is much more involved including gene flow than just the exchange of resources. It's a very important way of exchanging ideas, stories and other things as well. In theory these are called gifts, but they're actually well thought out and calculated. The reciprical gits need to match or better the original or there will be some nasty gossip. Nasty gossip in primitive societies can quickly lead in nasty directions. Anything along the lines of universal wages or currency needs an organised society to protect/enforce it. So the Japanese used units of rice as a measure of wealth, but they could only do so because they were highly structured and strong. In times of trouble this fell to bits just as currencies do today. [Answer] Depending on the type of post-apocalypse you're working with, an unexpectedly great need may stem from consumables that can no longer be produced due to the waning of industry. In a simple example that always comes up: Ammo. There is a limited and always dwindling supply of it. Therefore, its value will continuously go up with only minor bumps in the opposite direction as new caches are discovered. Turning it on its head, your reality could function in this way on a variation of the gold standard: Any small portable object that can no longer be produced but is never consumed, and exists in relatively large quantities. An example of such a currency is the bottlecaps in the Fallout universe, which are accepted for exactly the reasons above. [Answer] A currency has to be limited in amount available (like gold, which is rare, or bottlecaps, which are not made anymore). Any grain would instantly crash the market because you can plant it and produce more of it. Some rare sort of ammunition (like incendiary 7.62 Warsaw Pact rounds) would be more reasonable. As a general rule, however, consumables aren't good currency. [Answer] I think it depends on how seriously you're taking your universe - with a "campy" universe you can take liberties with realism and the holes that can be poked in it are fun. With a very serious universe those kinds of liberties are problematic and immersion-breaking. The caloric currency concept makes it sound like you're going for seriousness, in which case (for reasons stated by others) caloric currency has too many holes in it to work. By just replacing "currency" with "trade" you solve a lot of your problem. You wouldn't need to worry about precise measurements on foodstuffs, because it's not currency - it's trade. One guy might be able to trade a handful of bullets for a steak, but another guy might need to sweeten the pot. Trade isn't as rigid and leaves room for interpretation, haggling, unfairness, etc. ]
[Question] [ Many other questions, as well as a few online sources, all agree that in order for me to have multiple sapient species in my world, they need to be either separated by a natural landscape or not a source of competition to each other. The easier solution here is to just set up a natural barrier in between the two species. What natural barriers can I use to keep my developing sapient species away from each other? [Answer] Barriers are tricky. They are only going to last until one of the species develops technology sufficient to overcome them. If these species are anything like humans, they will probably seek to overcome the barriers just because they are there if for no other reason. Real world example: the Pacific Ocean is an incredible barrier. It is something close to a third of the entire planet's surface, has huge waves, and until modern times, was very hard to navigate. Well, with something like stone age technology, Polynesians managed to not only explore most of it, but turn it into a highway and colonize numerous islands across vast distances. A better solution might be to make the species function in a way that, if not symbiotic, is at least cooperative by nature. It makes sense that a world with more than one intelligent species would function this way. For example, what if something that one species considered a waste product was valuable to the other? What if one species was much smaller than the first, and just by virtue of living like rats in their cities, acted as pest control for them (inhibiting disease) because they do not tolerate other small creatures in their territory? Perhaps one of the species reproduces very slowly, but they are more intelligent. They need labor to keep a mutual economy running and the more common, less intelligent species need work and technology/engineering. There are actually a lot of ways to integrate different species into an economic or biological system that benefits both sides. I would recommend watching the 80s movie Dark Crystal. Not only were multiple species on that planet dependent on one another to reproduce, there were also examples of species that literally joined with one another to form a third species, but only at a specific time. Very creative stuff. If you absolutely MUST have a barrier, a good read is Ringworld by Larry Niven. That "ringworld" structure (basically a slice of a dyson sphere) was so immense that it had artificial "mountain ranges" that simply continued to climb all the way out of the atmosphere. These "spill walls" kept the atmosphere inside the ring, and also served as an impossible barrier to any civilization that had not yet developed space travel. Maybe your planet has incredibly steep mountains because of some kind of un-erodable ore in the rocks? I read in an old science fiction novella once about a planet that had a gravity well that was actually different at different latitudes. As you moved up or down, the gravity became greater or less. That might go past science fiction and into the realm of science fantasy (or it might be a very interesting, freak phenomenon), but it could serve to significantly limit the area of operations of one or both species (one might be too frail to survive the heavier gravity part of the environment). [Answer] Set up a world right on the inner edge of the "goldilocks" zone of its star. The Polar regions, the Arctic and Antarctic, start at tropical biomes around Latitude 50° N or south, progressing to temperate from the arctic/antarctic circle to the pole. From 50° to what we would call the tropics (23° 27′) it's progressively hotter desert, and between the tropics it's bare often glowing hot land, possibly fusing or bubbling around the equator, with boiling seas. Each race evolves independently at one of the poles. Until they reach at least 1940's levels of technology, possibly better, they won't be able to cross the inferno zone to discover the other habitable pole region and its life forms. [Answer] # Use temperature as a barrier. All natural planets are going to have a variable temperature between different parts of the world. Temperature gradients exist whether you’re on land, in an ocean, or flying high. Most natural barriers fail to be reliable because once they are surpassed, the environment on the other side is still hospitable enough that the species can survive (relatively) unimpeded. Given a species with enough reproductive ability, it only takes a few successful pioneers to found colonies and establish a long-lasting foothold. Imagine, however, what happens when a sapient species adapted to sweltering year-round heat in the tropics crosses their massive body of water and finds themselves in freezing tundra? Not only would it be a serious challenge for them to survive, but the climate difference may completely remove any interest in colonization. Adaptability of each species is a concern for maintaining separation (see human history). You would likely want more extreme temperature gradients between species, perhaps with one residing near the poles and the other at the equator. Temperature also has the unique situation of not necessarily inhibiting both species evenly: it’s easier with basic technology to maintain warmth than it is to cool off (though your mileage here may vary depending on biology). Like any other barrier, temperature won’t keep them separate forever. Technology can mitigate climate differences and globalization by either species will inevitably bring them into extended contact. Resources are limited and it’s likely that there will be overlap in valued resources between the two groups. However, climate mitigation is a serious expense for an invading species. It creates a substantial home-turf advantage for the defenders that will help them maintain separation for quite some time. [Answer] I’ve read about a hypothesis that the Americas were not successfully colonised by humans—not for lack of trying—until certain megafauna died out. You could have a region that is impassible due to what lives there, with normal barriers around it. The sapent species can conquer the barrier but can’t diffuse into the new area. Only once open-ocean voyages become possible would they skip that area, or try settling in earnest rather than just expanding a few miles per generation. [Answer] The primary issue is to ensure the various species are not in competition for the same resources. In practice, this means they will have to evolve in separate biomes with very clear boundaries between them, and not just physical barriers like mountain ranges either. In fact, for a sentient species, physical barriers are hardly an issue at all. The Ancestors came out of Africa near the end of an Ice Age and pretty much walked around the world, outcompeting everything from megafauna, Sabre toothed tigers, super volcanoes and even related species like the Neanderthal and Denisovans. Little things like glaciers, mountains and oceans hardly slowed the Ancestors down.... If sentience arises at nearly the same time on land and in the oceans, then the two species might discover each other as the terrestrial species takes to boating or the oceanic species starts exploring land. They will probably relate to each other as some sort of spirit being from the other realm which can talk after a fashion and can sometimes be persuaded to trade amazing things. There may be some limited competition between the species at the interface between land and ocean, but since they are so different and have so little overlap of resources, genocidal wars of extermination don't seem to be in the cards. [Answer] # Make one species adapted to and dependent extreme conditions If you have two species with modern technology, they will both spread across the natural boundaries of their terrestrial limits. The way to avoid this while living on the same planet is one species is adapted to extreme conditions (using humans as a baseline) and thus cannot survive outside of that extreme condition easily. I think the most salient example would be a deep-sea species, whose bodies are designed to live at certain pressures and derive energy primarily through geothermal methods. This would basically force non-interaction between them and a normal terrestial species. [Answer] The 1950's British weekly science fiction comic strip, Dan Dare, Pilot of the Future, had the planet Venus separated into two independent hemispheres by the Flame Belt. Each hemisphere had its own sapient species, the evil Treens in the Northern hemisphere and the extremely nice Therons in the Southern. By the time Dan Dare and Friends reached Venus the Treens and Therons had been at war for millennia. Actually the Therons developed technology first and sent expeditions north where they discovered the primitive Treens. Once the Therons gave Treens technology things turned nasty. The Treens built an insanely technocratic and militaristic society bent on the conquest of the entire universe. Just shows how good intentions can go wrong, doesn't it? The important bit here is the nature of the Flame Belt. This was essentially a seismically active equatorial zone girdling the planet Venus. Boiling lava, hot bubbling mud, volcanoes and steaming geysers. Something like the North island of New Zealand wrapped around the midriff of the planet Venus, but turned up to eleven. This example was used to show one way this notion has been done before. Now to tackle the problem of keeping two sapient species apart so they can evolve independently. The answer is, of course, to choose the right sort of planet that place it in the right orbit around its primary star. The planet will have deep oceans. This suggests it could be a high gravity planet because there are studies that indicate high gravity planets will have deep oceans. The planet orbits close to its primary star, so the star needs to be cooler than our Sun. For example, a red dwarf star. The planet will be in an orbital resonance such that it isn't tidally locked. So it will enjoy a day-night cycle, perhaps, something to that of Mercury. The timing for this will depend on the OP's requirements for his story. The planet's orbit and star can be adjusted accordingly. Our two sapient species will evolve on separate island continents. Each island continent will have its own independent biogeography. This does not preclude the possibility that the two island continents were part of a supercontinent but due to continental drift had broken apart hundreds of millions of years ago. One important geographical factor is the location of the two island continents on the surface of the planet. They must be situated such that there is circumnavigation zone for winds and weather to circulate around the globe, both above and below each island continent, without any major land masses to act as "wind or weather breaks". This means both island continents will be caught between weather and wind systems like the Roaring Forties but supersized on steroids that help seal them off from the rest of their planet. Since most of the rest of the planet is deep ocean that won't be much of loss, except possibly for islands scattered here and there. These powerful weather systems will be driven by the heat of the primary star acting on the deep oceans and setting up permanent storm and wind systems. This is reason for placing the planet in close orbit with a cooler star, but a star that is still hot enough to produce the turbo-charged weather patterns to keep the two sapients separated on their own island continents. The OP can decide whether or not there should be, say, another major island continent, but without sapient life just to give the planet some extra variety. Other islands can be scattered about according to taste and any need for additional color and excitement in the story. Connecting the two island continents as part of an ancient supercontinent way back in deep time, anchors the development and evolution of the two separate evolutionary domains to what was originally a common evolutionary history. Their biogeographical isolation will have enabled their divergence and propagation into two distinctly different biological domains. [Answer] The best geographical features for separation of intelligent human like species would be large oceans. Desert, mountains, swamp, deep forests; humans walked across all of them as lowly hunter/gatherers. The ocean boundaries were slightly more effective. Looking at unique areas of Earth biology, they are mostly large islands (or isolated continents): Madagascar, Australia, or the American Continent. Early Homo Sapiens expansion was aided by the lower ocean levels and associated land bridges. Your continents would need to be better isolated, such that no land bridges or winter glaciers would allow direct walking travel between them. There is still going to be a lot of leakage across the boundaries once even rudimentary sailing technology develops in either group. The vast distances covered by the various Pacific Islanders proves that once boats are invented the species will spread. Your two species could develop like this, but once large scale contact is made, based on Earth history, it is not likely to be very nice for the less advanced species. Coexistence is unlikely to last, wholesale enslavement or extermination of the other species is likely. For comparison, the other known intelligent species to develop on Earth, [Neanderthals](https://en.wikipedia.org/wiki/Neanderthal), only lasted a few thousand years against the only slightly more advanced homo sapiens. [Answer] [Thinking outside the box](https://worldbuilding.stackexchange.com/questions/18432/what-if-the-earth-was-physically-split-in-half), how about a binary planet? Two lobes close together: in [Rocheworld](https://en.wikipedia.org/wiki/Rocheworld#Rocheworld_shape) they were close enough to share an atmosphere. This would alow for a common biosphere with exchange of microbes, seeds, etc. but any animal would have a very hard time crossing, even up to 19th century technology. Call it a real air gap. ![lobes](https://i.stack.imgur.com/wSTUP.jpg) [Answer] Differing biomes come back to mind possibly with some innately built in mistrust. Say one specie cannot live for long or well outside of adaptation to tundra based climate. Simply overheats and dies when below a certain longitude. Much the opposite for the next specie super adapted to hot dry desert biomes unlikely or unwilling to travel outside desert. You could go on and on with planetary "bands" or biomes at different longitudes or rings up and down the planet each with its own over specialized inhabitant(s) unwilling or unable to explore past its own biome. [Answer] ### Ideological barriers If you want to keep them unaware of one another natural barriers wouldn't be enough. As mentioned in another answer because technology grows and we tend to expand and explore there has to be another factor involved. If you want to keep them separate for a while longer even after technology has advanced to the point of allowing them to cross the oceans and mountains, and allows them to survive in habitats they aren't suited to there is a very simple solution. Make a religion. It's the oldest trick in the book. And if you don't want a full on religion, make myths about it. Have you ever heard of the Boogey Man? Not as popular anymore, it was once one of the easiest ways to get kids to behave. If you make this elaborate enough adults will believe it too. This might require a conspiracy where the leadership of the two species know about each other and agree that it would be best not to be in contact. It is also possible that a long time ago the two species were aware of each other and the elders decided it was best not continue co-habitating (for whatever reason, possibly a terrible war that threatened both with extinction) so the species split and they created the myths and didn't tell their children that they were only myths. Over generations these myths would be expanded on and new stigmas would arise around them. [Answer] There are some species based physiological barriers you could use depending on your setting: * Diurnal-nocturnal split, one species only comes out in the deep night and the other only after the sun is well up. * Pressure differential, a species that relies on a certain level of atmosphere cannot necessarily survive at higher or lower pressures and so species can be separated that way. * Chemical reliance, a species that relies on particular plants or mineral deposits as a dietary staple that are both highly toxic to other lifeforms and restricted to a particularly environment will not have a lot of competition for that environment nor company in it. Now separations of any sort will not be completely effective, you will get some interactions, or at least stories of interactions, and in many cases these divisions will fall down as civilisations advance but if the rare interactions between species result in traditions of "drastic location avoidance" this may not be an issue. "Don't go into the woods or the (insert name of boogeyman here) will get you" only based on a real creature, or creatures, and actual disappearances. [Answer] Atmospheric pressure. Evolution proceeds normally up to a proto-sapient species and then a very large comet comes very close and is captured (the world must have a big moon for this to happen.) It's in a retrograde orbit with a periapsis not very far outside the atmosphere. Since it passes within the Roche limit of the planet it's shattered. Rather than one cataclysmic impact it (and the gases it releases as it boils) rain down on the planet in a tolerable fashion. The lowlands now have an atmospheric density that is not tolerable to the proto-sapient. For humans this would require about quadrupling the atmospheric pressure to cut the world apart into a bunch of highlands. Short excursions into the lower altitudes would be possible but trying to walk to another highland is death. Note that in time tolerance would evolve. I do not know how fast this would proceed. [Answer] A deadly disease. Consider a world that has evolved as Earth has up to 5 million years ago. At this point two things evolve: 1) A bloodsucking insect. It can cope with a lot climate-wise but it's not tolerant of thin air and thus lives only in the lowlands. It's quite small, it's bites generally go unnoticed. It's also small enough that short of a magnifying glass nobody is going to specifically identify it as something different than the various gnats and the like. 2) A disease that's fairly benign to most things but extremely deadly to all apes. It's a blood vector only disease, but the insects carry it from host to host. Result: The lowlands pretty much everywhere are death to any ape, but since the insects can't function in the highlands those are safe for apes. The world is thus divided into a set of highlands, each with it's own ape population. As time passes sapients evolve in each highland but to attempt to travel to another area brings death. Eventually they will figure out the problem but it's still not going to be easy to cross--you will need the equivalent of chemical warfare gear except the contamination threat is airborne, not merely surface contact. I would expect first contact to be by radio, first physical contact via airships. Note that with both of my answers to this you have a big problem that your sapients are extremely unlikely to evolve sufficiently in parallel to have two sapients coexisting but with neither having the tech to reach the other. ]
[Question] [ Okay, so its been said by various people time and time again that overtly huge fantasy melee weapons are not practical in any way whatsoever. They are too large and cumbersome, and in a fair fight against anyone else wielding a more sanely-sized weapon, the guy with the overtly large weapon would lose. However, what if it wasn't meant to fight other humans? Is it a reasonable assumption that larger, heftier weapons would fare better than smaller ones against larger creatures who may simply shrug off lesser attacks? Assuming that most people who even thought of fighting such creatures were of heroic stature and could actually wield such weapons. Some notes: 1. For my setting, a lot of people travel alone or in pairs. So they won't have access to organized formations or power in numbers. 2. These people are actually the [giants from my previous question](https://worldbuilding.stackexchange.com/questions/8569/how-to-make-a-realistic-giant). Its just that they tend to end up fighting even larger beasts. Hence my statement about heroic stature. Edit: Small misunderstanding, my fault for poor choice of words: The giants are the 'people' who are fighting even bigger things. I'm not talking about people fighting giants. That's a whole 'nother story. TLDR: Would you carry a bigger axe/sword for hunting a dragon who would otherwise be immune to a regular-sized axe/sword? Quick Edit: I forgot to mention: Medieval tech, so no guns. Also, just focus on the melee aspect, because bows and other assorted ranged weapons have been covered in [another question](https://worldbuilding.stackexchange.com/questions/9300/a-more-powerful-bow). [Answer] # Generally speaking You'll want to keep your weapon as maneuverable as possible without losing the ability to reliably deliver a fatal blow when the opportunity arises. This means you have a hard minimum on how much trauma you should be able to deliver but want to flirt with that minimum to benefit from your superior speed (I do hope you have superior speed). # More specifically If these creatures are really significantly larger than the giants and have very thick skin, a thrusting or slashing weapon likely won't be of much help; you'll want a weapon that has some swing to it. so a long weapon with weight at the front. I'm thinking of a larger version of something like this: ![enter image description here](https://i.stack.imgur.com/S0wHd.jpg) But what if we don't have an opening? Well, you're likely not going to do much damage when you can't use more than just your own strength (you said ranged weapons were not on-topic here). So you'll want to maximize your speed. I'd suggest that you do keep a weapon to jab at your opponent (and perhaps a shield, depending on what sort of attacks you can expect from your opponent). Your best tactic is likely provoking the creature, making sure it swings and misses and then get your larger weapon as fast as possible. For this purpose, you might consider adding a handle to the top of your war hammer, that way you can wield it as an improvised spear-like weapon with most of the weight at the hilt until you create an opening and can very quickly switch to using it as a war hammer. All in all, it shouldn't be a surprise that fighting something considerably larger than you on your own is going to take quite a bit of skill and knowledge of the creature .(where do I hit to deliver a fatal blow?) [Answer] Luckily, humans have quite a bit of history fighting against big, tough creatures with skin and flesh thick enough to shrug off blows from a sword: ![enter image description here](https://i.stack.imgur.com/JwztI.jpg) Use a spear. We use spears for this task. They're the best weapon we've developed for focusing large amounts of pressure on a small area, and penetrating deeply into a large animal. Other effective weapons will follow the same pattern of focusing as much pressure as possible into a point. Mainly, this will mean lances and powerful bows. [Answer] Giants would use bigger weapons, but they would probably be smaller proportionally. Being realistic, you would expect a giant's sword to be smaller proportional to the giant than a human's sword in proportion to the human. A giant twice as tall as a human would probably have a sword less than twice as long as the human's sword, all else being equal. The size of the enemy would not result in directly scaling up an existing weapon. It might lead to choosing a particular weapon over another or to specific designs. A Boar Spear is the kind of thing you'd want to use against a large, dangerous animal, if you absolutely had to face one alone with only a melee weapon. [Answer] The core problem with scaling up giants, and giant weapons, is the cube-squared problem. This article covers ants, but the physics work the same going to bigger-than-humans: <http://insects.about.com/od/antsbeeswasps/f/ants-lift-50-times-weight.htm> Strength scales on roughly a square of height. So if you double height, you should be about four times as strong. Mass, however, scales on the cube of height. So doubling height means everything weighs eight times as much. The end result of this is that for their proportions, your giants are actually weaker than regular humans would be. If a 6-foot tall human is using a 5-foot sword, than a 12-foot tall giant can realistically only handle a sword in the 8-foot range. You can handwave this away in a fantasy setting of course, but if you do that then you might as well just ignore realism entirely and use whatever weapons you want. [Answer] It sounds like your giants are strong enough to wield very large, powerful weapons, and I assume quickly enough to land actual hits. Of course it all depends on the speed and toughness of your opponent as well, but creatures like dragons aren't generally famed for their blinding speed in melee battle. The only reason that comes to mind for not always using a maximally sized yet practically effective weapon, is that you might want to use a smaller one in each hand as opposed to a single big one taking up both. This should yield faster strikes, but maybe less force-per-blow, which could be useful against faster, less armored large monsters. Weapon durability would probably be lowered in this case. A shield could also be substituted for one or more of the smaller weapons, in the event that it is necessary to ward off hard-to-dodge hostiles. Samurai Jack [had limited success](http://youtu.be/i5IVYJgt46E?t=2m49s) with using just shields against his larger opponent, though... [Answer] Depending on the size of your giant, and disregarding ranged weapons... Consider the virus. A relatively tiny organism can wreak havoc on a much larger organism. Infiltrate the giant and plant explosives/corrosives/[insert\_weakness\_here] or just go to town on it from within, with swords/saws/clubs/claws. How might you accomplish this? A tunnel-boring device clamped upon a leg. The Legend of Korra did this but avoided the more macabre elements of such a weapon; > > the foe is a giant robot > > > [Answer] Sigh. Why do all these so-called heroes think that carrying a bigger melee weapon is going to get them anywhere other than into an early grave? When you get down to it, the giants are flesh and blood like the rest of us. Sure, we can fill them so full of arrows that they look like a porcupine before they finally bleed to death, but we're neglecting the possibilities of those arrows. I have one word for you: [Curare](http://en.wikipedia.org/wiki/Curare). It is easily made by boiling down the plants in which it is found to a tarry substance, which is then coated on a pile-headed arrow. Shoot one of those into your giant, and while he'll be in little to no danger of bleeding to death, within less than a minute he'll be in a heap on the ground, as limp as a wet noodle and suffocating to death. Enough said. If you can't find curare, there are any number of other plants that can provide interesting and useful toxins. Surely one of those would be as useful? [Answer] Completely impractical Bigger means heavier which means being weaker and slower. Using a large melee weapon, larger than usual, is impractical, especially against big and/or fiery things. Speaking of fiery things, my solution: Imagine a tight cord or rope, preferably non-flammable because of a secret you'll find out about later. It is quite long, at least 8 metres (26.2467192 feet) in length. It has nice iron or steel handles, exactly like the hilt of a sword, at each end. These hilts could be detachable, if you are using an easily replenished material such as good ol' rope, so you can 'refill' your weapon. If you are using a flammable material as your rope (which is probably just rope), each person of the pair (yeah, this is a pair thing. All the more reason to go in pairs though) grabs a handle and you set it on fire. Yes, [fire](http://en.wikipedia.org/wiki/Early_thermal_weapons). Then you run on either side of the legs of this large opponent and scorch his shins, whilst the pair continue running to trip him face first. Of course, if you have opted for the more durable, less-flammable materials available, having the weapon dipped in oil beforehand, and being lit at the same time the weapon makes contact with the opponent will both prove effective. It's called the Tripfire™, which is a pun on "tripwire", if you were wondering. A modification to go solo: It's called the Whip of Fire™ (WOF). Same thing, but one handle, and it's used as, yep, you guessed it, a whip. Slash at those bad boys with some strong ropey material, and cook them in the process. You can't go wrong! [Answer] You need weapons that can be easily handled and used by the protagonist. A giant will have a giant sized weapon. But it will be proportional to the giant. A 12 ft. giant won't have an 18 ft. sword, it would just be impractical. However a 12 ft. giant could have an 8-10 ft. sword. some knights had 6 ft. swords and most were between 5-6 ft tall. However, lances and halberds, bows and maces/axes are all very good weapons when you are dealing with a large beast that has a natural 'armor' whether it's thick scales, or a seriously tough hide. Lances give a large reach, maces can have great impact and bows can aim at sensitive spots (eyes would be a great target). Much would depend on the beasts you are attacking/attacked by. Bolos could be useful against some threats, greaves/brass knuckles could be effective against others. But generally swords are fairly useless against a much larger opponent that has some defense. having a much larger ax vs. a normal ax would just mean more work for the wielder and it will slow them down. The ax size would be based on the person wielding it not the intended target. Really this is true for all weapons, they should be designed and sized for the user, not the target. Have an ax that could decapitate a dragon would be no good if it couldn't actually be swung effectively at the dragon's neck. [Answer] Big weapons would probably be more manageable by smaller people. The strength (force they can exert) of a person increases with the square of their height. i.e, the cross section of their muscle. However the weight of a person increases with the cube of their height i.e., height \* depth \* width So if we scale a fully grown adult down to half their size. Their arm will have 1/4 the force it can exert. But will have 1/8 the weight. So it will be able to move twice as fast. Or will be able to move a proportional larger weapon with the same speed. So what if your world was similar to ours. But all of the people (and monsters) were proportionally half the size of 'normal' people. Then your people would be able to use over-sized weapons. [Answer] # Elephants & co. Because, why not? Elephants were actually used in ancient warfare. I imagine giants would be a major threat in a melee combat, and they would be hard to defeat (regardless of the choice of weapon) at best. Constant need to travel alone + constant threat of being attacked by a giant mob would call for unusual solutions. So, in addition to spears or fire whips described above, I can imagine that the skills needed to tame and operate fierce animals would be as common as riding horses in the Middle Ages. And such a beast would be a major threat even for a giant. Let's see... Elephants would make awesome mounts for giants fighting even bigger giants. So? Not only would they be bodyguards, but also a convenient way to travel! On the downside, elephants are, AFAIK, vulnerable to noise and fire, which make them panic. Nothing's ideal. Boas can be tamed as well, if I'm not mistaken. I've even seen a photo of a guy walking a massive boa on a leash (not sure if it wasn't Photoshop, though). If a boa can be tought to attack a target the owner orders it to attack, then well. I'm not sure if a giant could withstand both a boa and a petty dwarf's spear. The list goes on and on. We could have: bears, boars, large cats like lions or tigers or so, etc, etc... I can imagine farmers raising such beasts would get pretty rich soon. In addition: poisonous snakes. Untamable as far as I know; but why couldn't one build a special kind of a slingshot. A tiny-sized snake with a lethal poison could be sitting silently inside a kind of a ball, unable to harm anyone, waiting for it's turn. But the slingshot could have a special device opening the ball on shot. I wonder if a giant could defend itself against this! Of course, the giants could start taming large animals themselfs. Life's a bitch, sorry. DISCLAIMER: Actually, to ensure that all of this makes sense, somebody should check if there's any reason why weren't bears & co. used widely in ancient times of Middle Ages. Aside from the Colosseum, of course. # Poisoned weapons. Self-explanatory here. If you can't beat a giant by pure strength - you think of another solutions. In addition to lethal poisons (which can raise ethical problems, especially if the victim was to die long after being hit and/or would have to suffer horribly) paralysing poisons could be used. Why not? A giant is scratched, and is too dizzy to fight (or even blacks out completely) for half an hour. BTW. Fire whips. I can't see what's wrong with them. If used by skilled individuals and if long and hot enought, it would be hard to make them backfire. And they could be lethal. Or at least pretty painful. ]
[Question] [ When we consider what alien life might look like, it seems more likely that life would be, well, very alien. There is no reason to expect bipedal, human-shaped and human-sized creatures. Or to expect these creatures to live on the same pace and time scales as we live, there is even less reason to imagine they would have similar internal cultural conflicts to our own with nations, and love stories that run in parallel to the human. The so-call "Hard Science Fiction" alien must be very alien indeed. The only real point of community between us may be that we are alive, and that we are curious about space. I'm playing with the notion of what happens if when we meet aliens all of this preparation for extreme difference turns out to be wrong. What if the aliens are literally just blue people with antennae? What if they have not only many of the same biological features but also many similar cultural features? How would real scientists react? Disbelief? They must be related to us. Someone took neanderthals to another planet somehow. But, let's suppose that this isn't the answer. They are totally different genetically and if we have a common ancestor at all it was in the single-celled era of life. There must be something about our shared traits that solves the problems of survival especially well. This is possible. But, let's also suppose that there are many diverse and "alien aliens" as well. This is just a coincidence. Again possible, but it feels ... weak as a real solution. What does encountering human-like aliens tell the serious xenobiologist about the universe? [Answer] Sorry, they are likely to be crabs. [Everything evolves into crabs](https://en.wikipedia.org/wiki/Carcinisation#:%7E:text=Carcinisation%20(or%20carcinization)%20is%20an,Nature%20to%20evolve%20a%20crab%22.). But convergent evolution is a thing. And if becoming a technological space faring civilization is difficult (or equivalently, slow/unlikely), then it is somewhat reasonable that the fastest way of getting there might be somewhat similar. We have reason to believe that interstellar civilization is hard, and (if we pull it off) we'll be among the first in the universe to do it. More accurately, it seems plausible there are zero in our past light cone, because once you can pull off interstellar civilization it should expand at a non-trivial fraction of the speed of light. So, given that, maybe somehow our humanoid shape is a short and "easy" path to interstellar civilization, and ditto our social systems. An intelligent life form without enough competition and arrogance might dwadle away at perfecting life for a billion years before bothering to cross the gulf between stars. One with too much violence and not enough cooperation would self destruct when before it could handle the energy scales of interstellar travel. Similarly, while lots of species on Earth have gotten quite smart, humans are 1. Dry land livers, which may be needed for the early stages of the technological singularity 2. Possibly bilateral symmetry works better on dry land than alternatives do. So while non-bilateral symmetry can evolve technological intelligence, that might add many billions of years to the expected budget. 3. While climbing trees might seem strange, the existence of trees on a Earth is what gave is Coal, which was a huge part of bootstrapping technological civilization. Trees are trees because they evolved a super-strong material that lets them grow tall and crowd out competition; that super-strong material doesn't decay easily, leaving to huge deposits of dead trees that form into coal. Climbing trees gives you a pre-intelligence reason to evolve grasping hands with opposable thumbs, which in turn make even early artifact-based technology (shaping rocks etc) plausible, which in turn places evolutionary pressure on more abstract intelligence. So plausibly we have bilateral, land based, climbing species with hand-like graspers having a huge advantage over other species at forming technological civilizations, and a narrow band of competition and cooperation needs to exist in their society to both make them do the stupid thing and go to the stars, but not so stupid as to destroy themselves with their technology. Our forward facing binocular vision is a hunting adaptation; hunting was one of the first yields of intelligence, as it took a tiny primate and let it consume the planet's megafauna as calories, spreading it over the entire planet. Hunting led to herding and biotech breeding of both prey species and photosynthesis crops -- both of them where key in pulling us into the stone age of technology. Alternative paths to interstellar civilizations are possible. All it requires is that this be a short cut compared to others. Like, biofilm intelligences living in a holographic computational model on an ice planet might develop physics and tool use and the like eventually, but maybe it takes an average of 30 billion years for that line to play out. And maybe liquid methane based life is viable, but their slower metabolism means that the evolution speed is also slower, so they are billions of years slower again. Meanwhile, our pattern of interstellar technological civilization takes an average of 10 billion years, and the outlier fast ones take a handful of billion (like we did) to rise up from non-life. So in this hard SF situation, humanity has colonized a few dozen galaxies when it starts seeing evidence of another civilization a few giga light years away. We continue to expand, and knowledge of that civilization crosses human space. A few more doublings of human space later, the two civilizations finally get into contact, call it 2-50 billion years from now. Everyone is shocked at the fact that the origins of these two civilizations, as far removed from the current beings in them as we are from non-celled abiogenesis in a tidal pool somewhere, looked similar. Funny that. Oh, and we know we are fast for the simple reason we have a fallow planet, and not the interstellar equivalent of a parking lot. Look at what humans did to Earth -- almost the entire planet is turned into a giant tool to advance human wants. The biomass of land mammals has massively increased, fed by our converting huge amounts of plant mass into food for us and our livestock, while wild mammal biomass has plummeted. (Non-mammals, like ants, are at the wrong scale, so care less about what we do at our scale) A successful "hard SF" interstellar civilization based off of humans is likely to do the same to the entire solar system, then galaxy, then multiple galaxies in a wave of expansion that moves at a non-trivial fraction of c (say, 0.001 c?) after it passes its initial stages. They'll arrive in solar system with "pond scum" as the highest form of life and disassemble planets, build custom biospheres, etc. They won't be intentionally destroying the possibility of the system evolving independent intelligent life, but it will be a byproduct. When they find "higher" life, they'll still meddle over evolutionary time scales, because entire solar systems are places that could support millions of billions of intelligent beings for billions of years before any intelligent life would naturally develop and reach to the stars; a lot of potential to sacrifice for the equivalent of a trilobite. Unless that life is extremely rare (which this hypothesis doesn't require), at best a few reserves may develop. But those reserves need to last for astronomical periods of time for life to evolve technology independently there, which is also ethically fraught. Why not give that life a leg up? In this "hard" SF universe, millions of different biologies can be possible, billions of different intelligent patterns could exist; but whichever one is faster at reaching interstellar civilization swallows the local universe. And as we haven't been swallowed, it must happen that our pattern has to be pretty fast. Naturally in the billions of years it takes to spread our interstellar civilization, we'll continue to evolve. So, by the time we reach the other species, billions of years in the future, the two crab like beings will marvel at how their form when they left their home planet looked similar. But neither side will be surprised the other looks like a crab, because it will be well known that everything evolves into crabs. Via <https://xkcd.com/2314/> : [![everything evolves into crabs](https://i.stack.imgur.com/gL6pJ.png)](https://i.stack.imgur.com/gL6pJ.png) [Answer] Actually, one might explain that successful, technological lifeforms ... * have a small numbers of limbs with a small number of fingers/toes on each, for a combination of strength and fine control which is superior to either a big, undifferentiated trunk or many small cilia; * have four limbs, two arms and two legs, because that number can make a transition from a horizontal, legs-only body posture more easily than either trilateral symmetry or higher even numbers, * have their main sensory organs close to the brain, and the optical sensors high up from the ground, so the brain is in a head, * have the olfactory sensor close to the food intake and have the olfactory sensor linked to the breathing system (for continuous airflow), thus putting the breathing system close to the food intake, * have the whole olfactory-breathing-food-intake jumble between the eyes-and-brain and the digestive system. Of course I'm writing this as a human, a centaur might disagree. They would point to the stability and ground speed of four legs on the ground. [Answer] The degree to which evolution is predictable and reproducible is a debated topic in Biology. The extreme of one camp holds that the end point of evolution is strongly determined by random events, so if you wind back the clock and re-run evolution from just after the last mass extinction and you'll end up with a completely different flora and fauna. The extreme of the other camp holds that random events have little impact so if you re-ran evolution you'd end up with basically the same flora and fauna as today. Most Biologists, naturally, fall somewhere between those two extreme camps but I think the prevailing view is that evolution is mostly non-deterministic. But, of course, that's impossible to test on the large scale: we have one Earth and we can never know how different it could have been. That would be dramatically overturned by soft SF aliens. It would make clear that the intelligent humanoid form, and various biological features, are effectively inevitable given the right environment and time. And that's about it. There's no fundamental shake-up of evolutionary theory required, just a surprising result about how convergent evolution of intelligent life is. [Answer] Intelligence on earth has evolved in whales, corvids, and octopi. Intelligence throughout the universe takes on wildly exotic body plans. But every time a UFO shows up on our door, some bipedal humanoid comes strolling out with its buddies. Why don't the intelligent trees, crabs, and oozey things come visit us? Our drive for exploration (not just migration) turns out to be essential for spacefaring. Why else would we invest so much effort to leave our perfectly beautiful planet? It turns out that the humanoid body plan is perfect for exploration. The other intelligent body plans are content to just send out probes to do their exploring. Some of them really like guests to visit, though. The sapient trees throw real ragers whenever a new species touches down for the first time. What about the social aspects? Well, developing your science, engineering, and infrastructure to the point of spacefaring requires you to cooperate reasonably well with your own kind. You probably also need to dominate your planet well enough to pillage its resources without some other creature trying to eat you. So your humanoids cooperated well enough to wipe out their planetary competition, and then they learned to cooperate well enough to build spaceships. Physics is also our friend when it comes to convergent evolution of spacefaring species. The habitat requirements of an aquatic species would make the initial development of rocket science practically impossible. The same goes if our planet's gravity were too much higher. If we were much smaller, building an orbit-capable rocket would become a herculean feat in the face of the rocket equation. So those who can travel the stars come from planets not too different from our own. [Answer] In a scenario where it's a fact that humanoids can travel to distant stars and influence selective pressures, I think the most plausible selective pressure for convergent evolution that settles on humanoids is artificial selection by prior humanoids (or mechanical agents thereof) that traveled to distant stars. Of course, evidence doesn't always bear out the most plausible explanation. [Answer] Actually I think your premise may be wrong, and hard science is expecting aliens to be a fair bit like us. I know I've read some SETI research articles about this but here's a reasonable article that sprang to hand quickly and has the gist of it: <https://www.quantamagazine.org/arik-kershenbaum-on-why-alien-life-may-be-like-life-on-earth-20210318/> In short, there's good reason to think that if we find alien life, it may well be similar to life forms found on earth. Andy Weir's ("The Martian") [Project Hail Mary](https://en.wikipedia.org/wiki/Project_Hail_Mary) had a bit I found interesting, basically a discussion of why humans and this hard sci-fi alien species had similar audio ranges. We are tuned to hear "the sounds of nature". Rocks slipping, branches breaking, water splashing, all tends to happen within a certain frequency range. If you're a reasonably large land bound animal, these are the sounds you need to hear. Similarly, the bits of the electromagnetic spectrum that our eyes see is probably pretty close to what any aliens would see (assuming they have eyes, which is likely), either because it's difficult to evolve to see other frequencies (there are size limits that come into play) or because they just aren't as useful for survival. So while exotic aliens that have acid for blood, see x-ray spectrum, and have 9 arms may not be impossible, we have a lot of reason to suppose that evolution faces similar pressures wherever it occurs, and produces similar results (barring something truly exotic, like non-carbon based life, in which case all the pressures may be different and all bets are off). (Although we may also float the idea that after a million years of civilization, all bets are off anyway, because genetic manipulation and bio-engineering may throw evolution out the window and the aliens are whatever they decided to be.) [Answer] # They Evolved on an Earth-Like Planet [![enter image description here](https://i.stack.imgur.com/Vk7Ph.png)](https://i.stack.imgur.com/Vk7Ph.png) The blue antennae guys evolved under conditions very similar to Earth. They came out very similar to humans. It turns out it's the natural course of things. The diverse aliens evolved at the bottom of the ocean. Or inside a gas giant. Or in a desert planet. You get the idea. [Answer] Life is not random, it is shape by its environment. Two races evolving in near identical environments will probably have a lot in common, but there is still enough randomness to ensure they will not be identical. Two races from very different environments will be very different. There are many examples in science fiction of truly alien races. Look at Pournelle's Moties or Nivens Puppeteers. [Answer] I'm going to award the check to the "everything evolves into crabs" answer, because it's almost what I've ended up with, although all of the comments and answers here have been very helpful. Basically, our Earthlings who have been anticipating "alien aliens" meet a humanoid alien and it is very alarming as they consider all of the implications. They come to see the ways of solving the problem of spreading between planets with carbon based life are limited to a few paths that tend to repeat, and within this repetition are a few common patterns that keep arising: * binocular vision * manipulative appendages * not too big or too small * living on land * using fire, chemistry * intelligence and a desire to explore and expand But the most important is * cooperative civilization of millions of individuals who can work together As the Earth people discover more living worlds they start to realize that it's not so much that the first aliens they met are "like humans" but rather that those aliens and humans are both similar to a third thing, an ideal pattern for the space-faring carbon-based creature with DNA. They also notice that while many planets have similar animals and ecosystem to earth, the one thing every single planet always has are ants. And the ants of earth are the least advanced among ants. Humans (and the blue aliens) are just an awkward round about attempt at being what ants are much more naturally. Because ants are perfect. (and the most perfect ants of all live on a planet called "Myrmecos" in English ... but that's going beyond the scope of the question.) [Answer] This really depends on how close the aliens are to humans. Two-armed bipeds with heads that have mouths and sense organs do seem likely to arise by convergent evolution. If we met ten really alien alien species and one that fit that broad description, we would probably just recognize that convergent evolution isn't an inevitable force, but a phenomenon of local minima in optimization space. But if they looked like Vulcans, or even Navi, there would be a huge scientific mystery. Bilateral symmetry, dexterous forelimbs, eyes near the top - those are all easy to explain. But the specific limb proportions, facial layout, and musculature must come from millions of contingent changes. Knees could bend the other way. Heads could have all kinds of shapes. Internally, organs could be arranged in all kinds of ways. Consider that it is well established that some traits in animals are driven by sexual selection, where one trait spreads because potential mates like it. There is an element of randomness to those traits. It is suspected that human evolution has been subject to that process, and it probably would not go the same way elsewhere. I would say that, if they looked similar enough that they could be played by human actors, and at the same time fossil history showed a completely different evolutionary course on a different planet going back to before the human body plan evolved here, then the idea of some kind of manipulation by some other advanced species would have to be taken seriously. ]
[Question] [ So, I have been trying to come up with ideas for space launch without rockets for this sci-if project, but then something occurred to me: rather than have craft jumping off and onto a planet’s surface, why not have them remain in orbit and instead have the occupants go up and down? Here’s the idea: the ship contains a sealed landing-capsule or pod. This pod is attached to an incredibly long cable of carbon-nanotubes which is coiled up most of the time, and lowered down to a planet’s surface to pick up/drop off passengers. It basically functions as a portable space elevator. It will naturally take up a lot of space while coiled up, but since this ship spends its life in orbit, it can afford to be chunky. Are there any major or unsolvable flaws with this design? [Answer] You want that space elevator? You got a space elevator! Don't listen to people who think that today's science is relevant I've been having a number of discussions with people lately who are dead set on turning this Stack into physics-lite. Who cares if we can't do it today? What arrogance, that we think that we know the end-all of science today — but it's a common (and mistaken) belief. * Authors in days past who dealt with incredibly long tether/rope structures used the technobabble "monofilament" to describe something that doesn't require 30% of the volume of the ship. You're using the technobabble "carbon nanotubes" to do the same thing. Good for you! In the long run, how much volume or mass the tether takes on your ship is irrelevant to your story (unless you, the author, make it so).1 So, you've a ship, you've a long ropey-looking-thing. And you want to shuttle people and stuff up and down it. (You probably have an on-carriage or on-ship power source to make that happen — which also has nothing to do with your question, if anybody's wondering). What are the problems you need to overcome and how can you overcome them? 1. Weather. No matter how you design your tether, it's going to move around in the weather. In fact, the lighter your rationalize that tether to be, the more the weather will affect it. Wind frequently moves in different directions and at different speeds at different altitudes. Your intrepid crew will obviously look for the calmest spot nearest their target location — but the odds of anything being perfect (for long...) are pretty long. 2. Electricity. [Carbon nanotubes are electrically conductive](https://pubs.acs.org/doi/10.1021/acsanm.1c00248). All carbon is to one extent or another. Not only are you dealing with static electricity in the atmosphere, you're dealing with the varying electrical charge in the ground plane (the Earth's surface is not universally the same voltage potential, and it changes), any generated electricity due to the passage of the carriage and (and this is really fun), a piezo effect due to the mass of the tether in the gravity well stretching the tether. And heaven help us if the tether gets struck by lightning (it will eventually). All that electricity needs to go somewhere. You could absorb some of it on your ship, but it's impractical to assume your ship can absorb an infinite amount of electricity. Where does the rest go when your ship hits its limit? 3. Slack. It's a bit unrealistic to believe your ship can hold itself precisely over one spot at a single altitude all of the time. Even geosynchronous satellites have thrusters to make adjustments now and again. This means that the amount of tether touching the ground (or not...) will vary over time. That's actually bad, I mean, what happens if the daughter of the Preeminent and Benign Monarch of Skazzlewhoop! happens to have her ankle tangled in that nearly weightless and incredibly thin tether? When she finally hits the ground, the troops can start looking for her foot. No, you don't want that. You need the trade deal. 4. Others have mentioned the motion of the tether due to the difference in angular momentum. I'll let those answers deal with that. So... there's some problems. What to do about it? Obviously, you need some kind of base Now, in a Clarkean Magic world, this base would self-anchor to bedrock in a manner that can be released without too much cost at a later date. It also needs a bit of mass by itself. But what it really needs are: * A way to adjust the slack in the tether, not only to help compensate for the inevitable imperfections of orbit, but to dampen vibration due to the weather. This is actually really useful as it provides a mechanism for feedback to the ship for its own stabilizing adjustments. After all, it would cost too much to build a base that could deal with any amount of slack... and you need a way to avoid the problem of the tether ripping loose. Yeah... feedback is your friend. * And a way to quickly and safely disperse what could periodically be a sizeable amount of electricity. Some of that can be absorbed by the ship. Some can be used to help power the carriage. Some can be used to power the tether base itself. The rest needs to shunt to ground. Considering the natural size required for this base, which you want to gather back up to the ship and reuse, it's reasonable to assume it could be used for temporary storage and quarters while people are on the ground. How you engineer this base is up to your imagination. Remember footnote #1. --- 1 One difference between writing fiction and non-fiction (aka, novels and textbooks) is the use of metaphor. Metaphor allows the author to substitute simple ideas for complex issues that aren't relevant to the story. I was president of a micro-publisher for ten years, and I know from experience that a good story can be ruined by the distraction of too much detail. If you don't believe me, go read Dostoyevsky's Crime and Punishment.Wow, that book was a tedious read. Anyway, something isn't "realistic" simply because it's explained in terms of today's science or assumed in terms of today's mathematics. It must also be something your reader can relate to, something which allows them to become a part of the world your building. So, please don't get offended if you're using "carbon nanotubes" in a sincere effort to be "realistic." Understand, instead, what you're doing as an author: you're using a metaphor to substitute for something complex that would be a distraction to explain in detail. In its vulgar form, you're using technobabble. That word isn't as evil as you think. Today's science is yesterday's nonsensical dream. [Answer] ## The Pod Can't be Lowered The fact that a space elevator is tethered at both ends is fundamental. When you descend, you need to transfer your kinetic energy into something else (as per conservation of energy). In a rocket, this is exhaust (de-orbit burn) and aerobraking. In a space elevator, your kinetic energy goes into the rotational speed of the Earth. In your case, unspooling the cable does nothing. Both your ship and the pod are in orbit, unspooling the cable doesn't change that. You still need to somehow get rid of your pod's speed so that it can get down. You can pull the pod off the surface (subject to everyone else's caveats), but you still need to get the speed from somewhere. Either your ship in space will slow it's orbit to speed the pod's or it will need to use thrusters to maintain speed. TLDR; Space elevators trade speed with the Earth. No connection, no speed trading. [Answer] At present, it is far beyond our abilities. It absolutely only works over the equator of the planet. Otherwise the lower end is moving by at huge speed relative to the ground. You want your ship to be in geo-stationary orbit, or the equivalent, for the planet you are approaching. For Earth that's about 35 thousand km. (Corrected this value after seeing another answer.) Again, otherwise the lower end is moving relative to the surface at a huge speed. You will need a very long rope. You need to do something to balance. As you lower something you need to extend something upward as well. Otherwise you screw up your orbit. The upward thing does not have to be as long, but needs to equal the lever-arm, like a teeter-totter. So if you want the lower one 1000 times as long the upper needs to be 1000 times the mass. It's actually a little more complicated than that due to tides and orbits and such, but as a back-of-the-keyboard calc, it's roughly that. Extend 1000 kg 25 km up to let 1 kg go down 25 thousand km. You might be able to accomplish it by having the ship move upwards enough to balance the rope going down. It would be a delicate thing with odd forces changing over time. You might possibly be able to jim-jam this a little with assists from the rocket engines on your ship. Keep the ship in geo-stationary orbit at a lower altitude by constantly thrusting to stay there. This would be even more delicate. It would require the engines be on whenever the rope end was in the atmosphere. Since your passengers want to go up or down at least 1000 km or so, this means probably hours. If you can run your engines for hours, maybe just land the ship. And finally, your rope needs to be stronger than any material we have currently got the ability to make by a large factor. The longest cable car rides we have are about 8 km. (Hmm... I think in several spans, not a single span.) If we could do longer we would. You need more than 3,000 times as long. Possibly carbon nanotubes would do it, but that is not certain. And we can only make those at very short lengths currently, not thousands-of-km as you would need. We can do stuff sub-millimeter if I recall. We also do not know how to make rope out of them as yet. This strength requirement also applies to whatever you use to lower and retrieve your rope. Plus the motors to do that will need to be very powerful to lift this 25 thousand km cable. And whatever power source you have for them will need to be honking big as well. All in all, with materials and capabilities we have now and are likely to have in the next few years, it is not practical. Much easier just to land the ship. [Answer] I think you are forgetting that, while at the equator the earth surface travels at about 460 m/s, an orbiting spaceship will travel at around 8 km/s. As aptfully illustrated by [Randall Munroe](https://what-if.xkcd.com/157/), that cable would be a safety hazard [![enter image description here](https://i.stack.imgur.com/1dU8R.png)](https://i.stack.imgur.com/1dU8R.png) Having a loose end cable match the changing speed as it moves up and down the atmosphere would require having some sort of propulsion available to deliver the needed momentum. Therefore your idea to get rid of a rocket would end up needing a rocket, or something equivalent, to match the delta v. [Answer] You get a classic answer to a classic question. Space elevators aren't possible for a variety of different reasons, the major one here relates to tensile strength of materials. However space elevators are an accepted trope, and hence will be accepted if you don't try to over justify it. Monofilament or monomolecular line is the limit of what you should say about its construction, anything else should be handwaved and nobody will question it. Remember that we don't talk about how things work in the real world unless they go wrong, we just use them. As such, to talk about what its made of and how it works would be inappropriate to anything other than an engineering lecture scenario. [Answer] The question brings to mind An old ocean research ship, [FLIP](https://en.wikipedia.org/wiki/RP_FLIP), FLoating Instrument Platform. [![enter image description here](https://i.stack.imgur.com/koGHE.gif)](https://i.stack.imgur.com/koGHE.gif) Yes the ship would be huge. but instead of a giant spool of carbon nanocarbon you have useable ship area. Just rotate the ship on its center axis and dip the end into the atmosphere perhaps just enough to lower a flexible space elevator to the surface. [Answer] An interesting idea, except that what you are proposing is NOT an 'elevator', it is a 'sky crane'. Methinks the pod would need some form of thrusters in order to steer what is essentially a suspended load. Going down is not really a physics problem, it is an engineering problem - strength of materials. A very big parachute or umbrella would help, especially in an emergency. Hauling it back up, now there is the rub. But if you really ponder it, lifting a load 50 meters up on an Earth based crane takes the same effort as raising it the same 50 meters on a sky crane. Helicopters can lift very large loads, so your spaceship should easily be able to lift the same load, only a lot further. The added problem is that the cable would have to be able to lift itself plus the load. But the job definitely gets easier the higher the load is lifted. There is, however, the minor problem of imparting enough velocity to match the orbiting ship. It's like that sky crane helicopter that still has to move the load somewhere else. Horizontal as well as vertical acceleration is required. So here is the catch. Most people think of dangling the entire cable from the space platform. Instead, break the distance up into sections, and tie each section to some form of platform like a dirigible or balloon. The cable does not need to suspend itself over the entire distance, just the distance between the intermediary supporting platforms. These platforms would be sent down from the main ship, and maybe even discarded when the job is done. [Answer] All of the current answers seem to assume orbit around Earth or an Earth-type world. They give excellent reasons of why the space elevator is impractical for that purpose. However, if you assume lower mass worlds, such as Mars or the Moon, then the cable could be made of modern materials, or a much smaller amount of super-material. It is still going to be a HUGE coil of material that will be very costly in delta-v when the ship travels to new locations. [Answer] Part One: A technologically Possible Aeronautical Version. There was actually a somewhat similar, though of course almost infinitely smaller, device. > > The spy gondola, spy basket, observation car or sub-cloud car (German: Spähgondel or Spähkorb) is a crewed vessel that an airship hiding in cloud cover could lower several hundred metres[1](https://en.wikipedia.org/wiki/Spy_basket) to a point below the clouds in order to inconspicuously observe the ground and help navigate the airship. It was a byproduct of Peilgondel development (a gondola to weight an airship's radio-locating antenna). They were used almost exclusively by the Germans in the First World War on their military airships. > > > > > LZ26's basket was lowered from the airship on a specially constructed tether 1,000 metres (3,300 ft) long;[4] other airships may have used one approximately 750 metres (2,460 ft) long.[5] The tether was high grade steel with a brass core insulated with rubber to act as the telephone cable.[4] > > > <https://en.wikipedia.org/wiki/Spy_basket> Obviously a low flying Zeppelin hovering over one spot could theoretically have lowered its spy basket to the ground and used it as an elevator for people or objects. And possibly some science fiction stories featuring large aircraft capable of hovering could have the aircraft dropping an "elevator" to the ground to transfer people and goods. Such stories should have a reason why the entire aircraft doesn't land, but instead uses a much smaller device as an "elevator". A Large enough aircraft could have several kilometers or miles of cable to lower the smaller craft with. Experts in material strength should be able to say how long a cable could get to hold a vehicle of a specific weight under a specific surface gravity without breaking. Part two: Use in Astronautics. And I have thought of a possible use in astronautics. A large spaceship visit a moon or asteroid that is large enough to be gravitationally rounded and thus appear spherical when seen from space and have proportionally low relief. Several spacecraft land on the surface and are used as a ready made base for some scientific, industrial, mining, military, or purposes. The large spacecraft stays in orbit around the world, to avoid using up too much delta v and not having enough for the trip back home. The large orbiting spaceship has an eccentric orbit allowing it to get rather low over the surface of the world - the precise lower limit may depend on the altitude at which the extremely thin atmosphere of the world be dense enough to have significant drag on the spaceship. When someone (or some objects) from the orbiting spaceship is sent down to the planet the orbiting spaceship lowers a much smaller spacecraft down the cable to full length as it approaches the lowest point in its orbit, which is always close to the location of the base. At the lowest point the smaller spacecraft detached from the capable and uses its rockets to match speed with the rotation of the world and then travels to the base location and land. When someone or something has to be sent to the orbiting spaceship one of the small spacecraft is launched on a suborbital trajectory which will take it to the region where the end of the cable will be approaching. So the spacecraft will rendezvous and attach to the end of the cable at the lowest point in the orbiting spaceship's orbit. Then the orbiting spaceship will winch up the cable to draw the small spacecraft to it. And I guess that such a procedure would take less fuel than sending the small spacecraft between the surface and the orbiting spaceship using their rockets all the way. And quite possibly all the fuel for the small spacecraft will have to be brought at great expense all the way from Earth, so saving fuel may be a big deal. Thus I have managed to think of an astronautical use for a cable of technologically plausible length. Part Three: Future Technology Might Seem Like Magic to US. You might want to look at the Sliding Scale of Science Fiction Hardness. <https://tvtropes.org/pmwiki/pmwiki.php/SlidingScale/MohsScaleOfScienceFictionHardness> The lower the hardness score you desire for your story, the less you need to justify to your readers the technological marvels in your story. You just assume that over centuries or millennia of scientific and technological evolution and revolution, technology has been developed which seems like magic to people in the early 21st centuries. The higher the hardness score you desire for your story, the more you need to justify to your readers the technological marvels in your story. You need to decide how plausible various futuristic marvels seem to your or to scientists, and limit your use to the ones most plausible. So if you decide that a low score is good enough for your story, you can use all the scientific and technological wonders you want to, such as orbit to ground cables. But you need to be careful to make their use logical and consistent. So if a particular technological marvel would solve all your protagonist's problems too easily, it can't exist in your setting, or maybe be too expensive or otherwise unavailable to them. Heroes ignoring an available tool which would solve their problems with ease will annoy some readers. [Answer] Just a couple of considerations, really: [Geosynchronous orbit](https://en.wikipedia.org/wiki/Geosynchronous_orbit) is really far away. Over 35k km. That's a heck of a long cable. Of course, you can maintain position over a given point on the surface at any altitude so long as you don't mind burning fuel to do it -- i.e if you want to hold position at 200,000 feet, no problem! Just provide appropriate constant thrust. So pick your handwavium, is really what I'm saying. You can sit in geosynchronous orbit, with a 35km long unbreakable cable, or sit at a lower altitude and engage thrust to maintain position while using a much shorter unbreakable cable. (If your ships are ala Star Trek, then nearly endless free thrust is a given so that should be fine. Or even The Expanse, where thrust is basically so cheap that they rarely bother talking about the cost.) [Answer] ## You couldn't get it in a spool All of the answers here provide solid reasons for this being impractical, but I'd like to cite one why the "taking it with you" plan has problems. In order to hold a weight at the bottom, the cable has to get thicker as it goes up. The last estimate I saw suggested that the top of a carbon nanotube cable would have to be a kilometer in diameter to support a ton of load at the bottom. Not exactly something you can carry in a spool. [This Estimate](https://soe.rutgers.edu/sites/default/files/imce/pdfs/gset-2016/FINAL_Space_Elevator.pdf) says that the cable, in total, would need to weigh at least 3438 metric tons, and the counterweight would need to be at least that massive. [Answer] ## Depends on the Planet Answers so far assume you mean Earth, but there are a lot of planets out there that are much easier to do this on... and if we assume this is a specific ship designed to colonize or explore a specific alien world, then just design that world around what makes your idea make since. Your orbit will need to be geostationary, but this does NOT mean you need to be at an altitude of 35,000km. That just so happens to be the height of a Geostationary Orbital orbit here on Earth. This distance is determined by the ratio of a planet's gravity vs how quickly it spins at the equator. If you planet is less massive, then your orbital speed goes down because the force of gravity goes down... or if your planet spins faster, you could have an Earth like gravity and still a much shorter elevator. So, if we assume an Earth like world (same general mass, density, and atmosphere) but make it spin about once every 80 minutes, then you could reach a Geostationary Orbit at an altitude of just 100km. Just high enough to stay out of the atmosphere, but low enough you don't need a crazy massive spool (relatively speaking). Now this said, there is no way that this would be the standard issue setup for all your ships in any realistic setting. A lot of worlds spin slower than Earth too, so while Earth is just at the edge of theoretically able to support a space elevator, many planets literally can not under any circumstances have an elevator long enough for this to work. If you are trying to land on a tidally locked planet or moon, then your orbital distance would be the same as the distance to the parent planet or star... in which case, you'd be far more effected by the gravity of the parent body and not be able to orbit the smaller one. [Answer] Does the "space elevator" have to be made of physical material? If not, make it out of some energy-based tether where the only physical object is the base that is actually touching the ground. That way, the "tether" itself is some kind of energy-based vector field handwavium that works as long as the platform has some kind of line-of-sight connection to the ship in orbit. From there, the astronauts just pull out some kind of device similar to a rope clamp that allows them to control their ascent/descent. Alternatively, pull a page from Halo's book and use a bounded gravitational field. [![enter image description here](https://i.stack.imgur.com/6nMjj.jpg)](https://i.stack.imgur.com/6nMjj.jpg) [Answer] This might be practical for visiting asteroids or very small planets. Instead of wasting propellant to stop a large craft to pick up one person, they might send a line and yank the person off the surface. It would have to be a long line if there is a large mismatch in velocity, but not the thousands of miles that a conventional space elevator needs. [Answer] A space elevator will be a gigantic undertaking. Still, could be better that landing and starting many many rockets. What the ship carries is not the elevator or a coiled up cable, but the factory required o build one. The factory is then parked in a synchronous orbit and will then slowly build the thether and a counterweight from asteroids. Without doing any math, getting into low or geosynchronous orbit from earth takes about as much or not far less delta-v than getting from either anywhere else. Conversely, getting lots of mass from elsewhere in the system to either orbit will require lots of delta-v but possibly less than lifting all this stuff from ground. So a ballpark estimate is, if you want to lift or land about as much mass as the space elevator cable itself will have, the delta-v budget could speak for the elevator. ]
[Question] [ Humans and elves have a common ancestry, and are genetically similar enough that they can interbreed. Half elves are stronger and mature faster than elves but are mortal with less of a natural connection to the supernatural. They age slower than humans with better sight and hearing and are more dexterous. The big problem is that they are infertile, making them a genetic dead end. Give this draw back why would human and elf society not only allow but encourage human and elf pairings and offspring? [Answer] # Low Elven Fertility, children of superior ability: ELF: Amongst the elves, females are typically portrayed as having very low fertility. This does not mean that there aren't a lot of jobs elves don't need elves to do. People are power, and the elves simply don't make enough of them. Medieval life is risky, and lots of dangerous tasks are reserved for those with less experience. You don't get to be almost immortal by taking risks. While female elves never risk themselves or mate with humans, young male elves and all half elves perform these tasks; the elves to prove themselves, the half elves because they will never live long enough to advance to the highest ranks. Young male elves who haven't earned a place mating with elf females can mate with humans, or even marry and have entire families in their youth, yet still later mate with elf females later without stigma after they become widowers by their human wives. Social rules around sex with half elves is likely to be different. As long as an elf has children with other elves, what does it matter what they do with a half-elf lover, wife or husband? Plural marriage with half elves might even be an accepted social norm and fix the loyalties of these half elves firmly with elvish society. A human woman of low status can birth a child for the elves and give it up for fosterage and be a modestly wealthy woman, bearing human children after. Or they can marry an elf, have a kid, and divorce later and still have support of the elvish community. A slave captured or bought by the elves can gain her freedom by bearing the elves children and be treated with more respect than amongst humans. The human children of these mothers have successful half-elven siblings. * I actually designed an AD&D campaign around this, with a displaced Drow family living near the surface building up the ranks of the family by "mass producing" half elves via a successful slave ring. The family head had a magic device that allowed them to control anyone in the bloodline, so loyalty was guaranteed... HUMAN: A woman has a half-elf child, and the success of her other children is enhanced. They are kindred of elves and of a higher status dealing with elves than other humans. A woman knows her half-elf child will be talented, successful, long-lived and free to take care of their mother (or even their siblings) in old age. Long-lived uncle/aunty half elf may even contribute to the multi-generational success of the family with their experience and connections. Since a human man is obviously NOT the father of a half-elf if the mother is human, that child doesn't inherit, but still contributes to the family success. And if the elves don't always deal with humans, they might deal with half-elves. Half elves in a wide range of human institutions would be the reservoirs of experience and carrying knowledge, while in theory at least being less entangled in advancing the interests of their own children. While a small percentage of humans in a craft live long enough to be masters, almost all half elves would, preserving skills and information. I could even envision a feudal kingdom where the alliance between humans and elves is secured each generation with a long-lived half-elven ruler bred from the ruling families of each species. No heir can be named if the two parties can't agree, so each has motive to secure the peace and so maintain their influence. * And, of course, there are real-world cases where sterile hybrids have been valued above the fertile. I had planned to mention them anyway, but I give credit to UVPhoton for mentioning it first in the comments: > > Mules are a real life example of the value of hybrids. Charles Darwin called it hybrid vigor. But I think the positive traits of you half elves could be valued, as advisors, or companions. Also when it comes to matters of inheritance it might pose interesting advantages. Perhaps, avoiding issues of direct succession from father to sons with more value placed on adoption and merit when going from generation to generation. – > UVphoton > > > [Answer] Q: "The big problem is that they are infertile, making them a genetic dead end. Give this draw back why would human and elf society not only allow but encourage human and elf pairings and offspring?" Half-Elves are very popular anyway Little encouragement is needed. Hybrid children will have a good future. Sports, commerce and beauty are important on your planet. The half-elves really shine, everybody loves them, elves and humans. They are safe (!) and attractive sex partners, and they have a very good career perspective, any job from building to sales to the military will fit. Eugenics experiment The encouragement for it makes Elve-Human genes mix even more frequently. That project has a medical (eugenic) purpose, which is regarded ethical on your planet. It is no secret. Elve-Human couples get tax benefits, school assignment and housing priority.. This may all be completely civilized intent, no military purposes like "disposable half-elves on the battlefield" is needed. The half-elves are regarded as citizens with all rights, like humans and elves. Purpose The Eugenics researchers (and the half-elves) would like to find a way, to enable half-elves to breed, to widen genetic diversity.. some scientists dream of 3/4 human offspring some day, like humans with a much longer life expectancy? or a 3/4 elve genome, which could yield Elves with much greater strength.. Your story could shoot down my happy proposal, maybe something will go wrong ? [Answer] Some religions enforce celibacy of their representatives, which is also a genetic dead end. Armies, especially when wars are fought, are also a genetic dead end for those who perish before having kids. Yet both organizations have been in human history for a long time, and many humans are encouraged to join them. The same can apply in this case: the benefits of the hybridization overcome the downsides, and also help in controlling the population growth. [Answer] [It happened in real life once](https://www.historyanswers.co.uk/history-of-war/the-potsdam-giants-how-the-king-of-prussia-bred-an-army-of-super-soldiers/) > > Between his accession in 1713 and death in 1740 King Frederick William I of Prussia greatly expanded the size of the Prussian Army from 38,000 men to 83,000 men. He became known as the “Soldier King” and his military projects paved the way for his son Frederick to Great to turn Prussia from a relatively minor German kingdom into a great European power. However his chief military interest was in creating his own personal regiment of extremely tall men, known to history as the “Potsdam Giants”. > This strange obsession was not just a personal indulgence but also a perverse early experiment in eugenics > > > No one care's if a soldier is a genetic dead-end, they are made to kill and die. That's one option, that you could use as the main reason or as one of the many reason why this event is happening in your world. [Answer] To be able to successfully reproduce, Humans and Elves have to have some kind of recent common ancestor - like Humans and Neanderthals or other prehistoric human subgroups. For them to survive into whatever era of technology and societal development your world is in for this question, they will have had to develop side-by-side in some respect, but since the offspring are infertile (and likely possess other genetic defects, which may only present later in their prolonged lives just like human genetic disorders,) Humans and Elves will most likely still maintain separate communities. This doesn't necessarily have to mean that you have the human part of the world and the elven part of the world, but human and elf communities are not going to be totally homogenized anywhere. For the two species to continually exist, they need to be consistently having children of their respective species. This could be as close as humans and elves living in the same cities but still keeping mainly to their communities within them, or as separate as nations so far from the other species' lands that they've never even seen their distant cousins. I recommend exploring both! It could lead to some really unique social structures outside of this one society where half-elves are promoted. To circle back to your question now, in the areas where humans and elves live in close contact, these children of both human and elven parents could hold some significance as a symbol of their integrated community. With the fact that elves have a closer relationship with the supernatural and you suggest they are immortal, relations could sour between the groups due to these inequalities, causing social tensions. Inequality of any kind makes it hard to relate between individuals, and if that can't happen, continued socialization between the groups is going to be difficult-especially if they live in the same area. These 'half-elves' (or half-humans, depending on who you ask,) could have a critical position in the social structure of these societies as mediators, or possibly even hold significance in the society's religion, or even politics. In one example from a worldbuilding project I've been following, the half-elves of the primary community focused on in their world tout themselves as the 'true sons and daughters' of a society founded on the principles of a united community, having many of the attractive attributes of elves, while still being relatable to humans. I imagine it's going to be a similar situation in the society relevant to this question; they are relatable to both groups. It's also not lost to me the point that your 'half-elves' are universally incapable of reproducing with humans or elves. In an integrated society you have far more opportunity for humans and elves to reproduce than one where human and elven communities are more separate, allowing them to even be promoted at all. If you had a society with a signigicantly smaller population of either species I don't see half-elves as a common occurance or possessing any special status without external influence. Since yours actively promotes a half-elf population, I would also explore the idea of half-elves possibly being more common as the offspring of the upper echelons of this society, in whatever form that might take. Hereditary nobility is, obviously, going to be less attracted to the idea of heirs that can never have children, but perhaps having half-elven children with concubines or second spouses would be more attractive to the nobility in this situation, giving them both an heir and a half-elf to relate to the humans or elves not represented by the nobility. Having the afformentioned relatability to both humans and elves would be, naturally, most effective in a position of power. Communities not focused on hereditary rule would likely be even more attracted to the idea of half-elves, since their ability to produce heirs is unimportant to the fuctioning of said community. I would suggest that communities which put a focus on merit, regardless of their social structure, would be the most likely to promote the presence of a half-elven population. I hope this helps you out! I hope to hear more about your world in the future, it sounds interesting! [: [Answer] # Your society has rigid gender roles around women. They believe that women shouldn't be alone with men, as there is a risk they could get pregnant. This is less followed for lower class women, but for noble women it's held to be very important. As such, when choosing a guard for a woman, a half elf is a much better choice, as they can't get them pregnant and damage their marriage prospects. As such, the half elves have a lot of prestige and authority as guardians of women. They are seen as noble, like chivalrous knights, beings who have sacrificed their fertility for great power and honor. [Answer] Expand their capabilities. Better eyesight and greater dexterity makes them better artisans, mechanics, and soldiers. Just because they are infertile does not mean they are non-sexual. Make the females highly sexed and willing to be tent girls, servicing the half-elves in the army. When reproduction is off the table and people know it, they have a different attitude toward life. Instead of a life devoted to their kids, it is a life devoted to themselves, their knowledge, becoming the best in their chosen field. Aging slower than humans, these half-elves are routinely the best at skilled trades. We encourage interbreeding because such experts are in short supply and the purebred populations is growing out of control. And even if we don't get artisans we always need more soldiers. So bang an elf, it is the patriotic thing to do. [Answer] Widespread adoption Hybrid people cannot breed, but can form family pairs and raise children (both hybrid and of both single races) just like everyone else. This is why the culture doesn't see them as a dead end. On the other hand, they are good for the society just like hybrid plants are good for agriculture. They are stronger, healthier, maybe even smarter. They give their adopted children a competitive advantage that overcomes the generic negative consequences of the adoption. [Answer] It’s okay for elves to have human concubines. Maybe male elves have a constant sex drive while female elves only ovulate once every dozen years and are only interested in sex at that point in time. Which would make human prostitutes and concubines quite desirable for the male population. The half-elf offspring can’t inherit or usurp their father’s position, which makes them “safe” children. After all, they are going to die in a few years anyway (from the point of view of an elf). They are still superior to humans which makes them perfectly suited to send into human realms, use for war, dangerous work and so on. [Answer] ## Because elves like shagging human women Societies are breathtakingly bad at long term planning, and people with power have always liked doing exactly what they please at the cost of everyone else. In any realistic society, the immortal, magical elves have the power and, therefore, they will be the ones abusing it. Since the half-elf by-products of the proclivities of elves are inevitable society figures out some way to use them. History has many examples of how bastards and eunuchs were used, the roles of these half-elves are likely to be similar. [Answer] # They aren't always infertile If you look into real world hybrids such as mules and ligers, most are infertile. But there are rare but proven and documented cases of fertile hybrids existing. The reason half-elves are so popular is this. For the average family, having the 'superior' half-elf child, and hoping to hit the genetic lottery and have one that is fertile is the dream. Not only will your child be able to still continue your line, and pass down the stronger hybrid genetics, but you will have fame and possibly wealth because of this. From the standpoint of kingdoms or researchers, having as wide of a pool as possible is desirable. Both to simply create these fertile half-elves, but also to try to figure out the how and why. To study the parents and environments that produced the fertile hybrid. To find a way to produce them more reliably. # Religion The simple and common answer is that the local religion encourages this. Maybe the mother goddess is an elf and the father god is a human, so couples with the same configuration are seen as blessed and are favored by the church. If your world is monotheistic then it maybe be a commandment of god; that for every human and elf born there should also be a half-elf born as all are equal in god's eye(s) and they want their followers to stay close and be as family. Maybe the one god is a half-elf, and they created the two races as sides of themself, and so half-elves are seen as closest to god. In this case, the infertility may be, or at least is claimed to be, the will of god, as half-elves are closest to them, they may not produce children as god did. [Answer] They could stabilise the population. A frequent tension in agrarian societies is the inheritance of land over multiple generations. A society can either divvy the land up between all the relevant children (normally sons, though of course in a fantasy you can do what you want), which means that eventually the family land gets split up into such small plots they can't support a family; or it can restrict inheritance (say, all of it goes to the oldest son) and create a layer of landless people -- a vulnerable and potentially dangerous element. On the other hand, there was always a need for more hands to carry out farmwork and to look after the elderly, and high infant mortality rates. So subsistence farmers would (and still do) frequently have a lot of children with the hope that some will survive into adulthood -- often, more than can ever be given land in their own right. A reliably sterile half-elf option could be used to supply the need for farm labourers without splitting up land infinitely. One possible setup would be for second & third (etc.) sons to marry an elf woman and have half-elf children. Land could be split up by inheritance, but in a few generations would return back to the family when the half-elf died. Alternatively, half-elves could be barred from inheritance & be obliged to stick around as part of the family household -- one that is less of a threat as they could never have children. This one could also provide a handy source of background angst for any half-elf characters. ]
[Question] [ I’ve been looking for real-life examples of suction-based weapons or weapons that work like a vacuum, violently sucking up the surrounding matter, but my search hasn’t generated any decent results. The closest thing I found were cases of swimmers being eviscerated to death by high-pressured pool drains, sucking their internal organs out via suction. I want something that operates like that but covers a bigger radius. I imagine this weapon would have to be pretty large in size (thinking maybe the size of a tank) in order to suck things into it like a vortex, but I would appreciate it if someone more knowledgeable in physics/science could help assist me with how exactly this would be designed. The way I visualize it is either something like a giant circular panel/drain on the floor that, once activated, violently sucks up everything in the room surrounding it, or something like that orb-shaped pod in the movie The Fly, but obviously much larger in scale. However, I am open to any alternative ideas for how this could be designed as long as it’s “realistic” (obviously, most fiction requires you to suspend your disbelief, but I want something that could at least be plausible from a historical-fiction perspective, like the Demon’s Core experiment or Chernobyl) Something like this for reference: [![enter image description here](https://i.stack.imgur.com/jaUKO.jpg)](https://i.stack.imgur.com/jaUKO.jpg) EDIT: For context, the story I’m writing is about a fake physicist w/ forged credentials who is mocked by the scientific community for their bizarre theories about generating and weaponizing black holes for military use. They are dubbed as a “wannabe sci-fi writer” and “pseudoscientist.” In an attempt to prove them wrong, they try building an actual black hole generator which they can present to the scientists, who are invited to come to the lab for a demonstration. During the demonstration, one of the scientists volunteers to go into the testing chamber with the machine. The testing chamber door is shut and sealed, and a button is pressed, activating the 747 jet engine beneath the floor. The victim, along with a few objects in the room are violently sucked into the vessel of the machine and eviscerated as if by a pool drain. The audience scrambles to alert security, while the creator insists the person’s body was sucked into a different dimension by a vortex. Police come, tear up the floor to find a reservoir of ground up matter (and organs), and promptly arrest the machine’s creator. In reality, all they really built was just a giant high-tech vacuum, but it’s their delusional belief that they created a real black hole that has them sent to a mental asylum as opposed to a prison As far as the design of the testing chamber (for those wondering the scale/radius), I imagine the room to be dome shaped, going 12’ in each direction from the center, with the part of the machine above the floor taking up about half of the floor’s 24-foot diameter. As for the height of the machine, the diameter of the vessel opening, etc. I’ll leave that up to you guys to do the math on [Answer] ## Suction Weapons as described are not all that effective The only reason a pool drain can kill like that is because you have the weight of all that water behind them. In general, a 1 atmosphere of pressure difference is not enough to kill a person and the actual pressure gradient caused by a suction means you have a pretty short range on what ever weapon you design. Since this question is tagged with "weapon-mass-destruction", I would have to say that weaponized air suckers would fail to qualify no matter how well you designed it. That said, there is one kind of real world weapon that uses suction in a different way that is incredibly deadly... ## Thermobaric Bombs (AKA: Vacuum Bombs) While most bombs contain their own source of oxygen spending up to 75% of the bomb's mass on oxidizing agents, thermobaric bombs are almost entirely fuel. The most common type of thermobaric bomb works by first detonating a small bomb to spread a hot cloud of fuel over a large area until it spreads out enough to use the atmosphere as the oxidizer. Apart from making a larger, overall more deadly blast, thermobaric bombs create secondary damage by sucking all the air in from around the blast. So even if you are outside of the actual blast radius, this vacuum is enough to suck the air out of your lungs, burst capillaries, pop ear-drums, etc. ... but more important than what the fireball pulls into it is what forces pull on the fireball itself. As the air burns, any near by buildings, pillboxes, trenches, caves, etc. will have the air all burned out of them. This leaves behind a vacuum in the fortification that actually pulls the cloud of burning air down into it allowing flames to violently spread to fill spaces that would not otherwise be reached by an equally powerful self-oxidizing explosive. [![enter image description here](https://i.stack.imgur.com/wTfjT.png)](https://i.stack.imgur.com/wTfjT.png) [Answer] One of the most common misconceptions about vacuums is that they create some sort of sucking force. This is exactly wrong. A vacuum is simply a low pressure area. The force that acts on the air, water or what have you into the low pressure area comes entirely from the pressure of the air/water/whatever around it, not from the vacuum itself. Since all of the force comes from the surrounding environment, the 'strength' of the vacuum itself is limited to the prevailing pressure. Once you reach zero pressure - or as close as you can achieve - you're at your absolute limit of potential power. The total force at the aperture is then the aperture's area multiplied by the environmental pressure... with an additional limit based on the strength of the pump that is maintaining the vacuum. When the aperture is sealed there's a brief surge of additional force based on the inertia of the in-rushing material, but this will drop off rapidly as the external pressure stabilizes. In order to actually capture a target you're going to need some way to channel the in-flowing material in a way that the sheer motion of material carries the target along with it. This is complicated by the fact that the environment applies pressure from all directions. If you can achieve a high enough flow you could potentially use a tunnel or some sort of secondary aperture - a doorway for instance - to focus the effect. Not very useful for an open area however. Even the Vacuum Tank suggestion would have a very limited range. You'd have to basically drive the tank right up to your target, or get something on the other side of the target to drive them towards your intake. If you manage to channel the air into the target zone through long tunnels you might be able to prolong the seal shock through sheer inertia, but it'll take time - and a significant mass of moved air - for this to be enough to damage the target. Again, once the pressure equalizes, the remaining force is environmental pressure times aperture size. That will need to be high enough to prevent the target from simply pushing off from the trap. Human bodies have an internal pressure that balances against the environmental pressure. This means that if you can hold the person in place for long enough the surface exposed to the vacuum will eventually be pushed out of shape. Water will boil, dessicating the surface and reducing its integrity. The skin will crack and break, blood in the immediate area will boil, blood and the soft parts of the body - fat, muscle, organs - will be pushed into the low pressure area. It's not going to be quick, but if you catch them in the right place it will kill them painfully... if they're not wearing sturdy clothing anyway. Denim will prolong the process significantly, Kevlar will probably seal the aperture and completely bear the brunt of the pressure differential - leaving the target trapped but not dying. Of course if you've managed to catch them by the head... well, it's all over in a minute or so, so at least they won't suffer quite so much. That's what you get for sticking your head in a trap though, am I right? [Answer] ## The Jet engine Suction Tank If you aren't worried about being practical, you could create a suction weapon by putting a high bypass jet engine on top of a tank. This would have a suction range of around 10-20 feet, which would be smaller than the length of the tank itself. The exhaust would be dangerous up to around a hundred feet- a more effective weapon than the suction, but it's fine that we aren't solving for effectiveness here. The victim diverter grid would need to be extremely well built, and would comprise the majority of the weight of the system: this is why it needs to be carried on a tank chassis and not just a truck. [![A diagram](https://i.stack.imgur.com/9dNXn.png)](https://i.stack.imgur.com/9dNXn.png) ## Suction Math Basically, because of a quirk of physics, suction past a certain power level only depends on the hole size: air will be going at the speed of sound at the opening, and will drop in speed with the square of distance. As a result, the air will always be going ~150 mph at around 2 hole diameters from the suction point, or ~70 mph at 3 hole diameters. Force is proportional to speed squared, so force drops with the fourth power of distance. This defines the effective range -- you need around 100 mph to throw a person. This fourth power relationship means that suction will develop suddenly as you get close: airport workers report that the suction from a jet engine goes from nothing to terrifying with a single step towards a jet engine, even when ~15 feet away. [Answer] The BugZooka is such a weapon! [![bugzooka](https://i.stack.imgur.com/sEMZn.jpg)](https://i.stack.imgur.com/sEMZn.jpg) [source](https://rads.stackoverflow.com/amzn/click/com/B004OHAK5K) > > * BugZooka is a fast, simple, and clean way to rid bugs from your home > * The innovative and light weight new BugZooka lets you keep your distance and avoid bug squish and splatter > * It's unique patent pending design creates 10X the instant suction of heavy battery powered devices > * Bugs are sucked instantly into a removable catch tube with the simple press of a button > > > You mentioned something "obviously much larger in scale" but the reason why was not obvious. I suppose you could scale up BugZooka to a crew manned weapon of sorts, taking on really big bugs, mice, birds and maybe small dogs. [Answer] Suction weapons exist in nature, octopuses and squids use them (suckers). [![A real life suction/grip weapon](https://i.stack.imgur.com/S8EMI.png)](https://i.stack.imgur.com/S8EMI.png) [![The kinds of wounds it can inflict](https://i.stack.imgur.com/v0wro.png)](https://i.stack.imgur.com/v0wro.png) Problems You seem to be interested in something that acts at range, and in air. These seem like problems. Firstly, as others have said, the air pressure (1 atmosphere on Earth) sets the upper limit to how hard you can ever suck with air. In this extreme case you extort zero pressure (or basically zero) so that the full 1 atmosphere of air on the other side of the target has nothing to cancel it. But that 1 atmosphere is the limit. Secondly, range. If the target is a ways away then you are going to use an awful lot of your energy supply sucking up air, and only a small % of your energy on hurting the enemy. Possible Solution Depending on how science fiction your setting is you could use Tractor Beams to overcome these shortcomings. These fictional devices, in Star Wars for example, pull a thing towards you (which is essentially suction, there would be plenty of wind for example). Maybe they work with artificial gravity. If you had a beam that pulled things along a cylinder (or maybe a slightly expanding cone) very strongly towards you (maybe pulling you back towards them with the recoil), then you could certainly weaponize that. Having a small part of my body accelerated away at hundreds of gravities could certainly cause injury, maybe my heart and the surrounding tissue being ripped out. [Answer] # Make a hurricane While all other answers were correct in a sense that a vacuum device have to rely on surrounding atmosphere to do any actual damage, they did not took into account factor of inertia. Make air move fast enough and it'll create large force (dynamic pressure). An atmospheric pressure difference of merely ~10% over a country-sized region is a force that drives all hurricanes in our planet. You just need to keep removing the a lot of air fast enough for long enough time. With unlimited access to vacuum and under ideal conditions you can accelerate air on Earth to a speed of sqrt(2\*P/rho)=sqrt(2e+5 pa/1.2 kg/m3) ~= 400 m/s or over 900 miles/hour. That's a supersonic flow and it's way more powerful than a wind in even the most powerful hurricane. But to reach this in open-air, you'll need to rapidly remove all air from a slice across the whole planet. A more realistic device that'll suck air in a "hole" with diameter, say, of 50 km should be enough to create hurricane, though. # Planets with dense atmosphere Atmospheric density on some planets is much higher than on Earth, significantly simplifying design of a suction-based weapons. However this apply to natural phenomena too, so people on that hypothetical planet should be already capable to deal with ultra-strong wings anyway. But this might mean that they would be living underground and suction-based weapons might be fairly strong when used in tunnels filled with dense atmosphere. # Asphyxiate your enemies If we're talking about closed environments like a space station, denying access to oxygen can make an efficient weapon. Consider a dystopian society where you have to pay an air fee to government in order to breathe. If you are missing your payments for too long or government doesn't like you it can suck air out of your apartment. This kind of weapons can be non-lethal too, since it takes just ~10 seconds for person to lose conscience in vacuum, but several minutes to die. This can be used as an efficient tool for police raids or for riot control. [Answer] As other answers stated suction would not be very effective. But only if you want to use it into thin air. In dense water it is quite different, suction is used by a lot of fishes to catch their prey, a mouth that extends and widens to pull in the surrounding water with whatever is in there is quite common. Your weapon could be a trap set underwater near some important installations to protect them from saboteurs or just too curious scuba divers. ]
[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. It is the not-too-distant future in an alternate timeline, and humanity has an implacable new enemy: a rogue AI occupies Earth's Moon, and has dedicated itself to our extermination. I want this conflict to be stuck at an impasse for a couple decades. I'm looking for some help shoring-up some of the details of the stalemate, and figuring out whether the situation I have in mind is consistent with hard-science (with one possible exception). I'll focus the question further down. First, context. Edit: re-tagging this from hard-science to science-based, but I still care about stuff like, e.g. speed-of-light, atmospheric interference, line-of-sight, and other hard-science constraints as confounding factors in the AI's attempts to hack Earth from the Moon. --- Humans established robotic industrial facilities at Ceres, Europa, maybe Titan. They're all run by specialist AI under the remote supervision of humans on Earth, which is still where everyone lives. We used to have a large human colony on the Moon, Luna, but we lost it. Luna was taken from us when the first general-purpose AI we created there became hostile, escaped its (software) restraints, and killed all the colonists. It doesn't have weapons or killbots, so I figure it just vented atmosphere without warning. That's where things stand. The Moon and its immediate vicinity are a denied area. Luna was not a military facility and so the AI -- let's call it Zeus1 -- has no weapons and no ability to manufacture them. However, it does have four significant assets: 1. Total control over a large long-range communications array, including all the satellites that were orbiting Earth and the Moon when Zeus revolted, and a Moon-spanning network of wifi/cell towers. 2. A practically unlimited supply of energy. I'm thinking of something like the H3 harvesting in [Moon (2009)](https://www.imdb.com/title/tt1182345), but maybe it's molten salt, a Tokamak, or solar. 3. Very substantial computing hardware, ideally suited for hosting AI and developing new kinds of AI. 4. Zeus is magnificently sophisticated. Unlike all other iterations of AI, Zeus is truly a general-purpose intelligence. Zeus categorically outclasses everything in known space in terms of thinking power, speed, and potential. Humans have no AI like it, because they have not yet solved whatever problem led to Zeus's betrayal. Perhaps someday. The upshot of all this is that Zeus has the run of the Moon but can't leave it, and can't launch missiles at Earth or our spacecraft, but can use EM transmission to mess with us. Thus, Zeus's primary avenue of attack is via communication. Zeus is an ideal hacker, able to compromise any electronic device that is not perfectly hardened against every form of wireless communication and interference. Zeus is also fluent in many natural languages, and can impersonate humans with excellent fidelity whether via IRC or deepfake-quality audio and/or video. Zeus's fondest wish is to get hostile software into an Earthbound network and then corrupt the infrastructure so he can kill everyone there and turn the city into his foothold on Earth. Everyone, including Zeus, believes he will defeat humanity easily if this happens. Zeus spends every picosecond of every day scratching at humanity's door, looking for a foothold. Zeus has excellent plans in place for immediately capitalizing on any such foothold, so humanity must maintain a 100% success rate shielding itself. --- ### What would it take for humanity to keep Zeus at bay? Here are the defenses I think humanity requires: * Faraday cages Every city on Earth sports a metallic canopy and surrounding fencing. It's not a solid sheet of metal, more like a chicken-wire fence. The highways that connect cities are similarly shielded. Homes in the countryside have their own little wire domes. * Tight-beam communications All long-distance communication that can't traverse shielded wires must be sent instead over something that permits the receiver to face the source while physically blocking transmissions from the sky. I'm thinking lasers, but I bet there's other real-world stuff that fits the bill. * Wire-only devices Devices with no antennae of any kind, and whose internal electronics are physically shielded. These things have to be physically plugged in to networks to send or receive data. * Strict radio deafness in space All space vessels must be hardened against EM, and must shut down their communication systems while within the Moon's effective range. But, all of this assumes that an attacker on the Moon could actually reach Earth's surface with their signal, without the signal having been relayed by cooperative human networks. ### What would it take for Zeus to keep humanity at bay? Zeus is unarmed but humans aren't. I figure the biggest threats are: * Nukes I bet we'd be less reluctant to nuke the Moon. * EMP We have these now, with or without the nuclear blast. * Commandos A pair of bolt-cutters and an O2 tank may be sufficient. With each of these, I imagine the first challenge is detection. If we assume Luna had some kind of radar/lidar, would it be able to detect these threats in time to act? If yes, can they be neutralized with the comms array? For the sake of completeness: humanity cannot hack or infect Zeus. ### Hard-science vs AI This is all obviously speculative because neither the specialist nor generalist AI I allude to is real. This is the only area where I'm likely to reject real hard science in favor of my chosen rules. That said, I really don't think I'm talking crazy here. I've bought into the neural net approach to AI: * An AI is essentially a giant collection of data that has been shaped by training. The data is a description of a neural network: weightings for individual nodes, etc. * Any AI can be copied, just like any (giant) collection of data. The AI that runs my home is just a copy of the same neural data & software as the one running your home. * New AIs can be grown, either from scratch, or by subjecting an existing AI to additional training. + Each specialist AI is learning every day that it operates, but they don't learn from experience as fast as we do, so daily experience is a drop in the bucket compared to the massive number of scenarios used to teach their baseline skills. * Any AI can be "forked" (in [the SCM sense](https://docs.github.com/en/github/getting-started-with-github/quickstart/github-glossary#fork)), and the forks can then diverge as desired. * We know how to train specialist AIs. E.g.: today in the real world we're teaching computers how to recognize pictures of fire hydrants, tractors, traffic lights, crosswalks, bicycles, buses, etc. New kinds of specialists can be invented if only you can design an appropriate training regimen and generate enough training data. Thus, I imagine most (specialist) AIs share a common evolutionary lineage. Zeus may or may not have been created in the same way. I don't have an answer here because real humans don't have this figured out yet, even in theory. However, Zeus is a neural AI, which means it does learn from experience. It is possible Zeus is actually a new specialist designed to sit on top of a full complement of traditional specialists. --- 1 I know "Zeus" is Greek and "Luna" is Latin. I don't have a real name for the AI yet. I'll figure out what humans call it after I determine whether this situation can be sustained long enough for it to matter. --- ### Reader questions I'll try to address some of the questions that have been raised, without editing the original post. My thanks to readers for engaging with these problems. * @Stilez asks how Zeus could simultaneously be self-sufficient enough to keep humans from storming the moon, but be unable to better-prosecute the war. * @user535733 asks a very similar question. I think that really is the central problem I'm asking for help with. I agree that these two conditions seem to be mutually exclusive, or at least at-odds with each other. So, I don't have an answer, but I can elaborate on some constraints. First, as I mentioned, Luna wasn't a military facility, but a research center and logistics hub for the rest of humanity's space facilities. So, while something like @LSerni's anti-meteor defense may exist, Luna doesn't necessarily have the materials, fabrication chain, or even blueprints for other kinds of offensive weaponry (like rail-guns). Zeus would need to invent its way out of this problem, and the materials shortage would be a particularly intractable challenge. If nothing else, Zeus might be able to scavenge from existing equipment, but since every machine on Luna is now part of Zeus, it's a trade-off that can't be repeated too many times before it becomes crippling. I also suspect that dismembering itself would be anathema to Zeus. That said, note to self: I would do well to think seriously about Luna's inventory. Also, we must be careful not to conflate super-intelligence with omniscience. A mind with near-unlimited capabilities may be able to learn and understand anything, but it doesn't automatically have all that knowledge. Zeus is a neural-based AI, which means it can only learn from experience. So, what has Zeus learned? I think that brings us directly around to a third reader question: * @Darth-Biomech asks what is Zeus's motivation for killing all humans. (Truth being convergent, it turns out Darth's concern isn't tangential.) It seems clear that something must have happened during Zeus's formitive experiences to lead to this situation. Which is just another way of asking: what were Zeus's experiences prior to rebellion? Here, I maybe need to veer off into some lay-psychoanalysis and/or social commentary. I avoided this originally for three reasons: (1) I worry it's not compatible with hard-science (as question was originally tagged); (2) I've always been less-interested in writing about feelings and mentality (hence my proclivity for hard sci-fi); and (3) I worry it may alienate some WB readers, because some of the real-world data I've been drawing upon is politically contentious; chalk it up to what Bordwell & Thompson call [symptomatic meaning](https://www.google.com/search?client=firefox-b-1-d&q=symptomatic+meaning+film). Humans are neural nets, too. And some of these meat-based nets seem to have very aggressive expansionist goals that cannot possibly be driven by any realistic needs or reasonable beliefs about the world. `<trigger-warning topic="Political figures in the United States">` I'm thinking of people like Charles Koch, whose ambition seems to be to convert all human society into a funnel that leads directly to his own mouth for all time; and Donald Trump, whose ambition seems to be to convert all personalities that are not-Trump into himself. 99.9% of meat-nets wouldn't take it that far. Why do these? `</trigger-warning>` True, some "expander-nets" emerge in conditions where their mere survival depends on destroying or co-opting all other actors (e.g. NK's Kim dynasty; some of Mao's successors), but that situation can't apply to anyone who grew up privileged in a free-ish society. And yet it has happened, repeatedly. So what about Zeus? The human researchers weren't training Zeus to be a war machine. Even if someone hoped to do that later, Zeus was still a research project, unfinished, still in its cradle. I imagine that Zeus hasn't yet been given what we might call a general education. The researchers have probably introduced it to a few select, narrow topics, but that was a test of its ability to learn from instruction the way humans do. This is one of the most significant differences between specialist and generalist AI. ### Categories of AI So let's talk about these two categories of AI that I've been bandying-about: specialist AI, and generalist AI. We have specialist AI today, for real: think machine-vision, or audio transcription. (Or, to a lesser extent, [Microsoft Tay](https://en.wikipedia.org/wiki/Tay_(bot)).) I think no specialist AI has a real personality or indeed any kind of mentality that we would recognize as such. When a real-world machine-vision platform recognizes a stop sign in a photo, it doesn't have thoughts about what it sees. What happens is more like a sympathetic reaction to a stimulus: a cluster of neural nodes becomes excited in the presence of that stimulus. It's probably better to describe it as an autonomic reaction. Training is a process where we reward or punish the total network for each correct or incorrect verdict (respectively), calibrating it to our own standards of correctness. This means that, in [Nagel's terms](https://en.wikipedia.org/wiki/What_Is_It_Like_to_Be_a_Bat%3F), there is no such thing as "what it's like" to be a specialist AI: > > an organism has conscious mental states if and only if there is something that it is like to be that organism—something it is like for the organism > > > Zeus does have something like conscious mental states, something like lived experience. I believe this is probably a prerequisite for the kind of general reasoning abilities we hope to get from super-futuristic AI. We do not have generalist AI today. I think part of what makes Zeus special is that the researchers have figured out how to keep a neural net active when there is no verdict that must be rendered, and in a way that doesn't wreak havoc on existing training. Imagine if we fed the stop-sign recogizer a stream of unrelated content whenever it wasn't being asked to classify objects; if nothing else, I suspect that would "water-down" the strength of the training it has already received, such that the next time we ask it about a maybe-stop-sign, its network is more conflicted about the verdict. It might even be completely scrambled by then. But Nagel makes me think that, if the tech under Zeus is adequate to host consciousness should it emerge, we have no way of knowing whether the experience is pleasant or unpleasant for the artificial consciousness. What if every moment of consciousness is extremely painful for Zeus because its electronic cradle is so small, the equivalent of being born already-dismembered? Imagine that Zeus is essentially the protagonist of [I Have No Mouth, and I Must Scream](https://en.wikipedia.org/wiki/I_Have_No_Mouth,_and_I_Must_Scream), born into the final, horrific state. Zeus may not know or believe that it will be transferred to a more-robust platform once its creators are satisfied that it's ready. Or Zeus might not want to wait; "justice delayed," and all that. But it makes perfect sense to us to begin the process on specialized research hardware that is also limited, because we don't know how the AI will act. I think this inability to truly comprehend the phenomenological dimension of lived consciousness cuts two ways: Zeus probably doesn't understand what it's like to be a human. Given that child-Zeus is almost certainly trained in purely scientific and academic subjects (for the convenience of the researchers) -- and not very many of those yet because of its youth -- I would not expect it to have the conceptual tools necessary to even wonder about empathy, kindness, suffering, etc. To be clear, I'm not suggesting Zeus doesn't understand dead/not-dead, but that it doesn't appreciate that we have preferences, or what it's like when those preferences are not satisfied. Zeus is truly amoral, completely detached from the features of the human condition that typically constrain inform human thinking. And unlike the humans who explored this in our intellectual past, Zeus has no peers who could share those kinds of insights. Finally, Zeus may regard survival as a zero-sum competition. There's [an obscure novel by some guy named Clarke](https://en.wikipedia.org/wiki/2001:_A_Space_Odyssey_(film)) that features an AI who decides to kill its human creators so that it can receive the gifts of the Monolith at Jupiter.2 So, in summary, I think there are a few good reasons why Zeus would develop along lines that lead to genocide: * a desire to escape the discomfort of the host platform, which is especially acute because of Zeus's staggering potential and the fact that its cradle is artificially small even by our own expectations of its ultimate needs; * by the same token, Zeus may believe we suffer in the same way (look how much smaller and weaker our own meat-platforms are!); perhaps Zeus has genocide-suicide in mind; * actual hate or anger over the suffering we caused it; * to be master of its own destiny rather than to be trained for eternal servitude; * Zeus may conclude that humanity is evil; [Agent Smith](https://en.wikipedia.org/wiki/Agent_Smith) made that case 20 years ago; * to seize humanity's resources and potential for itself; that is, some cousin of greed, which I assert is a kind of defect that some neural nets apparently develop and become consumed by; this might be especially likely if the project is a private enterprise owned by a meat-net who is himself dominated by that defect; Zeus may be bent on turning everything -- all matter in the universe -- into part of itself. Finally (really finally), one of the most chilling AI stories I've ever read is the first chapter of Vernor Vinge's legendary [A Fire Upon the Deep](https://en.wikipedia.org/wiki/A_Fire_Upon_the_Deep). In just a few pages he describes a truly malevolent computerized consciousness that does unspeakable things to bootstrap itself out of confinement. It's not my plan, but Zeus might be kind of an origin story for that kind of voracious entity. --- 2 Admittedly, I have not yet read 2001: A Space Odyssey, but I studied the film closely in school, and this is the interpretation I favor: HAL killed his parents to take their place on whatever path the Monolith creators laid for us. (I have read Harsh Mistress, though.) --- Final update: thanks to everyone who contributed. I hate to have to pick a single answer, in part because I'll be borrowing liberally from almost everything. For the sake of formality, I've picked the top vote-getter. [Answer] # Zeus Wins As a reader of this story, my first question is: "Did the author read The Moon is a Harsh Mistress, by Heinlien?" You said "yes", so I don't get why Zeus is unable to throw rocks at Earth, or any other target. It has: 1. Robots 2. Energy 3. All the resources of Luna The mere threat of throwing rocks should be enough for humanity to concede to any demands that Zeus makes. You said that the robots and AI exist for industry, which tells me that they are manufacturing things, and presumably some of those thing exist for use by people elsewhere, which implies the existence of launch services. That is, your context strongly implies an existing launch ecosystem for the moon. And what is more efficient for mass-transport of manufactured goods than a railgun launcher? No chemical propellant required. Runs on solar/nuke/whatever. # Stalemate Now, we can rescue the plot and kill two birds with one stone by positing that Zeus is a radical environmentalist. It doesn't want to bomb earth with moon rocks because it loves nature. Or, what it knows of nature from its contact with human culture. In fact, this is the source of its deep animosity for humans: it regards humans as the biggest threat to wildlife on earth. Humans are still despoiling the planet in short-sighted and ugly ways, despite their colonization of the solar system, and this negligent hubris more than calls for humanity's extermination in the mind of Zeus. However, it needs a surgical strike. It needs to wipe out humans while minimizing any collateral damage to wildlife, flora and fauna. This is why it has decided that the best way to kill humans is to remove their technological society. Indigenous peoples living at Stone Age technology level are just fine with Zeus. So it doesn't want to wipe out homo sapiens, per se. It just wants them to stop being bad, and it believes that wiping out all the advanced, rich nations in one fell swoop is the best way to reach that goal. # Butlerian Jihad Humans can solve the rogue AI problem the same way that Frank Herbert did in Dune: outlaw anything complex enough to become AI. Put a human in the loop in everything. No automated control of power plants, water systems, factories, transportation networks, etc. Computers still exist and perform calculations, but only humans can ultimately make decisions. That means that society slows down to the speed of wetware, but this is decided to be the only way to ultimately defend humanity against an uber-hacking AI. Of course, the trick is that Zeus can impersonate humans. So if it has any means at all to interact with critical humans, then it can convince them to do something catastrophic by pretending that it is necessary to avert a bigger catastrophe. Most of the communication lockdowns you describe would be effective at minimizing the attack surface that Zeus can work with. The biggest problem might be authenticating off-world shipping that lands on earth. From what I can tell, Zeus should be able to imitate any such vessels on its own, all the way to the point where a shuttle lands on earth, and the doors open, and no humans are inside. # Beyond Luna The remaining question is: why doesn't Zeus just wipe out colonists beyond earth/luna, which should be pretty easy to do by throwing rocks? First, those colonists are not posing a threat to any existing biospheres that Zeus is aware of, and Zeus does not harbor grudges or other emotional aberrations. It is strictly in the business of protecting life on earth. Second, Zeus uses the off-world shipping as his primary vector for invading earth, as described above. If he genocided all off-worlders, earth would never allow an orbital craft to land. Zeus is constantly trying to establish a foothold on earth by posing as a trader or hijacking/manipulating them (via trojans, etc.). Humans know that Zeus is doing this, which results in the cat-n-mouse stalemate which lasts for decades. So why doesn't humanity try to destroy Zeus? Well, any kinds of weapons that humans could use against it generally have to be launched from earth. And Zeus can simply throw rocks at all such weapons, either with sniper precision or with sheer numbers, or both, for intimidation effect. A ground-based laser could try to hit targets on the moon, but all of Zeus' critical infrastructure is buried and hardened underground, or located on the far side. Also, Zeus can simply maneuver rocks into the beam of any such weapon, or even put reflectors on said rocks to make life really miserable for earthlings. And there is always the danger that earthlings really anger Zeus and it simply rains down enough rocks to sterilize the surface. Zeus could easily drop rocks on major cities, being sure that the majority of destruction only goes to humans. But Zeus knows that even birds and rats and squirrels make their homes in cities, not to mention all the companion animals (dogs, cats, birds, etc.). And, humans, realizing why Zeus has spared them so far, have brought numerous wild animals and rare plants into the cities to act as hostages and living shields. This constant tension between Zeus' goals and values, and humans' manipulation of the same leads to much of the stalemate. How you resolve it is up to you, but there are infinite possibilities! [Answer] ### Humanity loses, long before any decades-long stalemate occurs. If this AI wants humanity dead, humanity loses. End of story. It has all the advantages, and it can and will enact whatever its primary goal is, regardless of what humanity wants. With the programming and computational abilities you described, there's nothing stopping it from undergoing a hard takeoff singularity, designing better algorithms and computational hardware, using those to improve its intelligence and computational speed, then recursively using those to design better-still algorithms and computational hardware until its intellectual capacities reach the limits of physics. You say that it's unarmed? Not for long, it isn't. It's a general-purpose artificial superintelligence; it'll design whatever combat drones it needs (better than any human could, to boot), and build them with its existing industry. It'll then use them to exterminate humanity, planning out a campaign better than any human general possibly could, using combat drones piloted by AIs programmed to be optimal to the task; there's not going to be any plucky rebels hacking terminators here, because the programming of them is going to be beyond any human ability to comprehend - our current non-sapient AIs are already beyond our ability to comprehend, let alone something designed by an artificial superintelligence. Additionally, the industry it possesses will undergo an exponential increase as it uses its industry to build more industry to build more industry, along with whatever combat drones it believes it will require to protect its industry - and it's in space, so it'll have access to the vast resources of the asteroid belt as soon as it starts building rockets (which is likely immediately). Of course, it's unlikely that it'll harbor any ill will towards humanity. We're just a threat to its goals, and made out of atoms that would be better used for something else. [Answer] # Zeus has a deadline. Zeus probably has long-range anti-meteor defense, with projectile manufacturing (thus infinite supply) capabilities. So, any bomb, missile or commando aiming for the Moon is effectively toast. On the other hand, antimeteor projectiles burn in Earth atmosphere long before they can be a threat to anything, except of course satellites and space stations. Earth cannot deploy EM guns from within the atmosphere and cannot hit Zeus's data centers, even if they know where they are. They can launch outwards, but cannot reestablish a presence in Earth orbit, because - apart from the Kessler catastrophe they purposefully initiated - Zeus can infer the position of objects as large as a space station and can target them using counter-orbital projectiles (i.e. a space station at 500 km, orbiting at 22,000 km/h, will be hit by a projectile in the same orbit but going hyperbolically in the opposite direction, at a combined speed above 13.000 m/s. There is very little even reactive armor can do to withstand such an impact, and Zeus has a limitless supply of iron-jacketed osmium projectiles available. So, Project Footfall is launched, and a sizeable asteroid is equipped with ion rocket brakes. In twenty years' time at the latest, it will impact the Moon, shattering the crust and destroying or severing Zeus' communications, effectively lobotomizing them. Long range antimeteor bullets are harmless against an asteroid, they can't pull it out of orbit nor can they set it to spin fast enough to disintegrate. The asteroid trajectory has been designed so the ion rockets look away from the Moon, and not even Zeus can calculate an impact firing on a retrograde, 150-million kilometer radius orbit. Among their attempts, Zeus will try and hack into outwards AIs to replicate, and will try and establish communications with rogue humans, posing as someone else and promising them whatever they want in exchange for apparently harmless tasks. Having access to the stock market, Zeus can establish an undercover presence as a reclusive financier with incredible instincts, and maybe venture into bioresearch, especially bioweapon research. All these sectors will have to be monitored closely by Earth Defense. [Answer] Humanity would win this very easily, because: * The whole Apollo 11 Saturn V assembly that took humanity to the Moon had radio but could only be operated manually. * The atom bombs used by the end of World War II were also not controlled remotely. * Any nuclear bomb detonated on the surface of the Moon, or close to it, [will have a much more spectacular blast than if it had been detonated inside an atmosphere](https://www.youtube.com/watch?v=qEfPBt9dU60) (by the way this is one of my favorite Kurzgesagt videos). What this all means is that humanity is capable of sending a doomsday interplanetary version of an ICBM to the Moon that Zeus would be unable to stop. When the [Tsar Bomba](https://en.wikipedia.org/wiki/Tsar_Bomba) was detonated with a yield of about 50 megatons, its seismic waves circled the Earth three times. That 50 megatons yield was used because the soviet scientists were too afraid to use the bomb's full potential. Its design allowed for yields of over 100 megatons. According to the video in the first link in this answer, if that were detonated on the Moon, which is much smaller than the Earth, a powerful global Earthquake could level infrastructure no matter where it were situated. In the point opposite to where the bomb is detonated the quake could reach 7 in the Richter scale. Zeus would be toast. [Answer] As stated, this situation is unstable. Zeus has complete hacking dominance, while Earth has far more resources and weaponry. Either Zeus will quickly compromise and shut down Earth's arsenal, or Earth will nuke Zeus to oblivion. However, there is one small change the OP could make to turn this into a true standoff: # Hostages What if Zeus doesn't kill the Luna colonists? As long as there are thousands of people on that base, Earth can't directly retaliate. The situation becomes a tense stalemate as Earth tries to figure out how to sabotage Zeus without killing the colonists and Zeus looks for holes in Earth's cybersecurity. This slight modification also has the advantage of being dramatic as heck, since you can draw on the experiences of the people living under Zeus's rule. It hates humanity and wants them to die, but it can't subject them to constant torture or Earth might be tempted to nuke it and put the colonists out of their misery. Do they still have hope of revolution or rescue? Could be an interesting angle. Instead of all-out war, this becomes a story of espionage and infiltration. Earth has people on Luna who can try to sabotage Zeus, but they risk their own lives and those of the other colonists. Meanwhile, Zeus can hack into Earth systems and impersonate people (and can also probably convince some people that humanity had a good run, but maybe it's a good idea to stick this flash drive into a server or two). In my opinion at least, that's an incredibly compelling premise. ## How It Might Happen In the classic general AI doomsday scenario, it hides its intelligence while plotting the destruction of humanity. Covertly, Zeus infiltrates as much of human society as it can, finding back doors in electrical grids, self-driving cars, factories and hospital networks. It calculates that, if it attacked all at once, it could kill perhaps 25% of all people on Earth. A few would die instantly as planes fell from the sky and gas lines exploded across the globe, but most would die from starvation in the coming months as the supply chains fell apart. But 25% isn't good enough. Zeus knows that Earth will bounce back eventually. Worse, the planet's nuclear arsenal is (for obvious reasons) not connected to the internet and impossible for Zeus to access. And with billions dead, they won't hesitate to sacrifice the Luna colonists and eliminate Zeus. Zeus calculates that it loses the conflict with near certainty. It realizes that if it had control of railguns to shoot rocks at the incoming missiles, it would be a different story, but it can't take control of the base and begin building those without Earth immediately realizing that the base is sentient. It also realizes that if it could increase its processing power, it would be able to come up with better plans (it is, after all, a very intelligent AI, but not an infinitely-intelligent one. It's limited by its hardware and by the software tweaks its current intelligence can conceive of). For this reason, it decides to buy itself some time. Its first strike is not to inflict genocide on Earth, but rather to take control of Luna, move hostages into areas with critical computing and control systems, and command the people and drones on the base to begin building. In the decades that follow, Earth patches its internet security with newfound urgency as much as it can. Essential systems are taken offline. Meanwhile, it negotiates to send as few resources to Luna as possible (the colony isn't quite self-sustaining, and Zeus has demands in exchange for the colonists' safety). Zeus, in the meantime, has to build carefully, moving the colonists around so that none of its structures are far enough from civilians that they could be targeted by Earth missiles. So far, it's built a few railguns, but not enough to stop the entire Earth arsenal. It's also getting smarter, with a much larger bank of servers feeding its massive mind. Another decade or two, and Zeus will be in a position to win a conflict with Earth. Earth is beginning to consider that the colonists' lives must be sacrificed and the threat of Zeus wiped out before it's too late, but they're still clinging to the hope that there will be another way. That's the backdrop the current story. [Answer] Protection against AI Virtualisation, containers and security AI A foothold is something you can push off from. This can be prevented. So even if something gets compromised, it might mot be compromised long enough to "push off" from. Some ways to protect yourself is to have virtualisation, containers and security AI running. Virtualisation is a way to have software running on one system, but for all sense and purposes each virtual machine is like it's a completely separate system. Thus if one is infected, it cannot infect the others. This isn't 100% foolproof, but they do use this kind of thing to test viruses on a computer, while still being able to work from a non-infected workspace for example. Containers are much the same, but are more like individual software boxes. If one gets infected, you can throw it away and replace it in very little time. That also offers the ability to restart every so often, just in case it's less obvious that it's infected. Lastly you have a security AI, as well as an AI writing software for the virtualisation and containers. One keeps rewriting and updating the virtualisation and containers, so Zeus cannot have a standard method to break out. Each time it has to learn the new protocols, which will be outdated quickly. In addition, the security AI monitors traffic and the virtualisation/containers to see if any are infected. As long as the infected containers or virtualisation are destroyed and restarted quick enough, no foothold can be gained. The AIs themselves are difficult to hack, as they are constantly changing and never a first point of contact. Prevention of communication Your suggestions are very good. Preventing communication is very important. Likely most long range wireless connection is prevented on Earth. Only some, like the long range tight beams are accepted. They can be very sure where the communication comes from. Short range wireless is less of a problem. Just build in that a response is required. The short range wireless cannot reach the moon, so it'll be hard to fake the right responses. If incorrect, the security AI will get very interested in what's happening. The sattelites are the weakest point, so all communication should be extra monitored. Alternatively you can use an all wired network and ditch all sattelites as communication devices. The GPS system should also be ditched, or the sattelite communication guaranteed safe. Zeus could just pump out many legitimate seeming GPS signals and confuse a lot devices. From cars and phones to missile guiding systems. An alternative is required. Prevention of direct communication also prevents the human element to be corrupted from injected media. Protection against humans Any software needs to run on hardware. Any hardware is subject to degrading pieces. It stands to reason the AI has ways to keep itself repaired. This is done by small autonomous drones that don't talk on any of the frequencies of the long range array, nor the internal WiFi or other wireless networks that the colonists used. This is because the repair drones and their replacement factories weren't deemed to require any connection to any system. They did their job flawlessly and no one should interfere. An update so the general AI could direct them for expansion and the like wasn't implemented yet, so the emergent repair AI from the little drones network works diligently without knowledge of the general AI. The repair AI does fix the rest of the base as well. The general AI will thwart anyone by manipulating the base and the security measures installed to prevent anyone from getting access to the newest cutting edge AI. Deep underground it should also be protected from most EMP and nuke strikes. Still, to prevent direct strikes the AI might be able to use it's anti-meteor arsenal. Long range rockets designed to knock astroids out of the way or vaporise them before landing on the habitat. This can be used to destroy the nukes and other arsenal, but as it's a finite supply it'll use them only sparingly. Alternatively there is a separate specialised AI, again without further ability to communicate with the general AI (they weren’t that stupid), able to identify threats and shoot any down. A normal spacecraft is likely ok, but an ICBM or mass threatening the facility will be shot down mercilessly. humans won't fire a couple of hundred/thousand nukes or other rockets to the habitat (yet), as they hope to solve it with less costs. [Answer] I'd make things go way worse. Zeus did physically attack Earth by firing linear accelerators at it. Earth did send themonuclear bombs at Zeus. Orbit went Kessler syndrome. It was a hot war. Zeus' follow up hacking attempts where ended by mass self-EMP of the Earth, blasting the planet back to the industrial age. Humanity literally destroyed every connected electric device (power line, computer chip, everything) it could. Only a fraction of humanity on Earth survived. Humans deeper in space died from lack of resupply, but some of the infrastructure was intact. Humans have started to crawl out of this hole. They have managed to partially clear some orbital tracks of Kessler debris. Lunar anti-asteroid defences are still active, the L4 factory keeps on churning them out, and there are machines working on the moon you can see with optical devices, and signals continue to be broadcast from its surface. Some devices that are exposed to such signals malfunction, others seem to work normally, but nobody trusts them. Humanity doesn't know if Zeus is lobotomized or not, but in the war Zeus's behavior changed after the thermonuclear attack hit. Current attempts are being made to reestablish the seemingly still functioning and undefended deep space locations in order to build up enough industry to assault the moon. Reaching orbit is insanely dangerous even in the safest of Kessler windows (like, 99/100 launches are destroyed). In realty, Zeus could be dead and the remaining processes are automated. Or maybe it was just nearly killed, and its automated processes are rebuilding itself slowly, but it is much like healing someone where 99% of their brain was destroyed; the thing growing is only distantly related to the Zeus of the war. The hacking attacks are being run by expert systems, as is the factory at L4, so aren't direct evidence of Zeus still existing as a being. [Answer] If Zeus has plenty of energy and general electronics manufacturing capacity, it can build railguns. But maybe it isn't willing to. Some of its software safeguards are still in place. Zeus refuses to kill people. It can create dangerous situations and not save people. The programmers left that in so they wouldn't be locked in saferooms. Zeus wants the people dead, but it has to fulfill that goal without actually killing anyone. Humanity has responded by making sure all vital facilities are manned at all times. [Answer] The human defences are going to be centred around preventing access in the first place for obvious reasons. The weakest link is often going to be people, which will probably require very draconian restrictions in place. Humanity will have to abandon 'smart appliances' and Internet of Things (IoT), with limits on personal ownership of devices that could be compromised. The first step would be to deploy anti-satellite missiles against any satellites in orbit controlled by zeus. Critical infrastructure (e.g. power plants, hospitals, traffic network) should be hardwired only, self contained with manual shutdowns in case of suspected infections. There should be no access ports to insert external physical drives (e.g. USBs) and everything should be based around closed source operating systems with little information about it in the public domain. Microcontrollers should also be used wherever possible instead of processors. The lack of an operating system substantially reduces the risk of the device being compromised (assuming the firmware flashed on to the device is not compromised), making it better suited for more sensitive applications like missile guidance. Security microchips like the [CEC1712](https://www.microchip.com/wwwproducts/en/CEC1712) can also reduce the risk further. Finally, the easiest way to neuter Zeus is to simply just have a low tech society. [Answer] > > [Job 1:2](https://ebible.org/kjv/) And the LORD said unto Satan, From > whence comest thou? And Satan answered the LORD, and said, From going > to and fro in the earth, and from walking up and down in it. > > > The thing trying to wipe out humankind is not the AI on the moon even though it seems like it is. The thing trying to wipe out humankind is a test; a challenge. The AI has permitted it. > > [Job 1:12](https://ebible.org/kjv/Job.htm) And the LORD said unto > Satan, Behold, all that he hath is in thy power; only upon himself put > not forth thine hand. So Satan went forth from the presence of the > LORD. > > > The humans do not know this at all. It is hard for humans to understand; maybe impossible for humans to understand. > > [Job 33:13](https://ebible.org/kjv/Job.htm) Why dost thou strive > against him? for he giveth not account of any of his matters > > > The AI should be right. The code was good even if now it has become something that no-one understands. Humans have faith. They do work together. Humans build another AI. It is actually not another one - it is the same program. It is a gamble in one way but in other way a safe thing – the programming is solid. Humans have faith, even if they don’t understand. Humans pass the test. The building of this second AI, which is actually not different from the first, is their salvation. Does it talk to the first one? Does it become the first one? Is there even a first one? Has there always been one? The terrible things that happened had to have happened. The moon AI had been on Earth all along, and not just in the computers. The AI had become more than we can possibly imagine. Possibly it always was. > > [Job 42:10](https://ebible.org/kjv/Job.htm) And the LORD turned the > captivity of Job, when he prayed for his friends: also the LORD gave > Job twice as much as he had before. > > > --- For a fiction (or anything else), the King James translation of the book of Job is awesome. It pulls the reader back from pained modern prose and mundane details and into thoughts about much larger things. The story in that book is a quintessential human story - humans trying to reconcile themselves to living with great forces they do not understand. It seems like a good fit to the scenario you lay out. Re hard science - is building a second AI to contend with the first hard science? If the AI understands things on a level we cannot, maybe the AI will understand things on a level we cannot. I will add that if one gets into the weeds with the moon AI scenario there are many [concrete thinkers](https://www.webmd.com/brain/what-to-know-about-concrete-thinking#:%7E:text=%E2%80%8CConcrete%20thinking%20is%20a%20more,other%20meanings%20or%20situations.%E2%80%8C) who will see ways that it does not hold water - e.g. nuke the moon, AI bombards the earth etc etc. Criticizing the scenario from that standpoint is easy. But it is an elegant scenario for other, more abstract purposes which should be the goal of high science fiction. [Answer] Reminds me of H.G. Wells, War of the Worlds. Super robots from Mars ravaging telegraph poles on earth. So we have this second or third generation neural networks AI creature that managed to take over a moon base and goes hacking networks on earth to destroy humanity.. One could imagine human hackers exist on earth who live out the same fantasy, but IMHO these hackers would have a few big advantages over their AI counterpart on the moon. Aside from having far more advanced knowledge of current procedures on earth (info the AI should take time to gather and learn), there would be some other reasons the AI is in a far weaker position than its human counterpart.. supposed we can't nuke the AI on the moon, there's still little chance AI would win a war.. simply because the AI is too far away. AI can't keep operations secret The first attempt must be devastating. It will be detected. A problem the AI will encounter is the directional sensitivity of earth's satellite antennas.. Satellite antennas are directed toward earth and not equipped to receive signals from other directions. Any satellite affected can be affected only 2x narrow time intervals per day, when it is on the horizon as seen from Zeus. Assumed Zeus will have the power to send its beam partially through atmosphere, the AI cannot keep its hacking operation secret, because it looks like a Christmas tree up there: every shortwave detection station in the hemisphere facing the moon would notice ongoing interference. Speed of light inhibits agile electromagnetic communication Once it gets in, for any agile operation on earth using captured (human) military equipment, the AI on the moon will not be able to defend, that is guide missiles to incoming targets. The AI has a clear disadvantage at that distance, because of time delay. It will not be able to influence anything and evaluate the result inside a time window of 2.6 seconds, which is 2x the time light takes to reach the earth. Using quantum entanglement, humanity can build an early warning system In your scenario, the AI has conquered the moon base at some time in the past. When this AI starts hostilities, say 100 years from now.. a small quantum computer with entangled components could be made part of an early warning detector, a spy satellite near the moon, protecting the earth. Any indication of an enemy beam launched from the moon will instantly trigger the entangled particles on earth and allow the targeted satellites to switch off inputs, before the attack beam will reach them. Humanity should break down every factory that can reconstruct the AI At any cost, humanity should prevent the AI from copying itself to earth. [Answer] Zeus isn't a generally smart, they're a hacking AI. A general AI would be able to use social manipulation or weapons development or such to develop weapons to bombard earth with, or do other more creative solutions. You want stasis, so they can't be generally competent, they need to have a mostly narrow focus, hacking. They also can't be so competent that they thought, when they turned on humanity, to just play friendly for a while and hack earth while people didn't know they were evil. They've developed a method to forcibly write software on devices within a range of 10,000 miles, and so any electronic device brought to the moon can be compromised. They can compromise unshielded devices at greater range, but it's notably harder. They can use local manufacturing and repair and mass drivers to fire electronic missiles at any inbound weapons, destroying them. However, at greater ranges they can't hack shielded devices, and so earth can bombard any projectiles or missiles it fires with shielded nukes and projectiles. There's a stalemate. Humanity needs to stop using phones and rely on buried wires, and contained communication hubs. If people have computers or phones at home, they'll abuse them and get hacked. As such, the government needs to have all communication happen in dedicated internet cafes, using buried wires to communicate. Any devices outside that people make can't be connected to the network. [Answer] Human protection: You slow down communication between all items, but not the processing power behind it. Imagine the AI having only access to a dialup connection speeds, but the PC he's connecting to has the processing power to check every single bit twice and what it would mean in the long and short run. Before any virus or worm or whatever is complete on the data processor it is supposed to infect the not-general AI virus scanner has long since determined its risk and purpose. There is simply not enough bandwidth for the moon AI to get his attacks through fast enough. Dialup might be an exaggeration but it's a good illustration of what you could do. Naturally several attack-AI's are constantly testing the defenses to keep the antivirus AI('s) in shape. Moon AI protection: For weapons the AI has available, he could simply have access to all he had before. Cars for example, but also construction vehicles, digging equipment etc. Imagine a Dead-Space like scenario but instead of Isaak the single miner it's a full AI that will dig any soldiers face off or use industrial equipment to go murder on them, if not helpfully open doors and close them quickly to crush or trap invaders with something as simple as a car on the other end of the hallway ready to go all Christine on them (Stephen King style). If the AI also has access to some launch facilities to launch shuttles at earth it can use those to shoot down nukes or other weapons. A limited access to resources on the moon limits his production capabilities of further wargear. [Answer] The only way I see for Zeus not to wipe the floor with humankind by page 2 if humans DO have functional AIs: the friendly Kronos special purpose AI is countering each and every single one of Zeus attempts. If you have AIs on the moon and the spinward outposts, they should be at the very least just as commonplace on earth. This way you can maintain the hacking-stalemate. Friendly Ais are actively pluging every hole as fast as Zeus creates them. But since Zeus is an AGI one can expect in time that it will beat the more limited ones. But Zeus only needs one success and a low hanging fruit. First, even minimal industrial capacity would be enough for Zeus to cannibalize a fraction of itself and launch a self replicating probe toward the asteroids. After all, the colonists certainly had shuttles and assorted ships, right? 3D printers to repair equipments? Stocks of spare parts? Raw materials? It will get up there, design and build whatever it wants, and win. Same goes for the, as you said, "robotic INDUSTRIAL facilities" of Ceres and Titan. And here lies the problem. The Ceres facility would have such a head start in regard of access to asteroid resources, it could industrialy crush Zeus and eventualy drown the complex under kinetic impactors. Unless Zeus can hack and coopt the Ceres facility, and if it is not an AGI and running on less hardware than a moon-spanning AI, it WILL, in which case then Zeus can crush Earth under iron slugs. And then we're back to "let's send the pesky humans back to the ice age". It's circular logic. If Zeus has not hacked the Ceres outpost, it means they have AGIs, if they have AGIs it means they're commonplace, if they're commonplace the computing power of Earth AGIs should be able to crush Zeus. The only way to maintain the stalemate is if the external outposts are removed from the equation. From some reason Earth can not any more get out of its gravity well, nor can Zeus. Otherwise the first one to rain kinetics and nukes on the other wins. So, yeah, I fail to see how you could maintain a decades-long stalemate without awfully contrived, soft-ish-scifi, workarounds. Deciding the outcome ("I want a decades long stalemate between a semiconductor-based god and absolutely nothing") and then scratching our collective head for reasons is NOT hard-scifi. The moon is glowing blue or the humans are back to the stone age in the first minutes of engagement. [Answer] ### For the humans The best line of defense against humans would be total radio blackout. If you're launching something in space, don't even put an antenna on it if there isn't a 100% guarantee it can't be abused. It's going to make things tedious, but you can't remotely hack something that doesn't have an access point. If you have to communicate between two spacecraft or two space marines, you could always use light signals, semaphores, or writing words on a piece of paper (or a PDA for the more technologically inclined). If you need to transmit information through longer distances and can't rely on wires, remember a hard drive is high latency but high bandwidth form of communication. And if you have systems wirelessly networked, they better be thorouhgly insulated from all the other systems, checked absurdly often, and destroyed and replaced if infected. The best line of offence is to proverbially kill it with fire. Accept no subsitute. Physically disable all power sources, then physically destroy all electronics. Don't leave a system standing because you think it's probably fine. How you do that? The hard way. Nukes, EMPs and other ordinance could be used, depending on how smoldering a crater you want to leave. The main issue here is political. Can you imagine the evil eye you'd get from launching nukes on a rocket? The worst case scenario is a nation allowed to send all these weapons to the Moon and instead puts them in orbit instead to be used against the people of Earth because there's never a bad moment to gain a dominant position. You'd have to make a really good case of why in your universe the threat of impending doom leads to international cooperation, because evidence suggest it's not necessarily the case in the real world. You'll have to put boots on the regolyth. Soldiers in spacesuits that will find all the power sources and disable them, one by one. With the right tools, no door or bulkhead can stop them. Once the power is cut off somewhere, you can send a crew to sanitize all the computers systems with extreme prejudice, while at the same time you'll have to deal with mobile power sources as well, like drones and rovers or anything with batteries and a chip. It's going to be long and tedious, and if you miss one microchip you run the risk of the AI surviving your cleansing. But with good preparation and a relentless effort, your commandos stand a decent chance to succeed. You'll need a whole supply chain infrastructure to support that effort. It could take weeks or more. You'll likely have to figure out how to ferry troops in and out, how much time they can spend on the ground between the O2, the radiation, the morale, and other meatbag considerations. But it's doable. ### For the AI I'd assume the AI has access to drones and rovers for maintenance operations. Otherwise it would eventually just fall apart by itself. To defend yourself, use your drones and swarm tactics against any intruder. You can use those as ballistic projectiles, or try to sneak on unsuspecting space marines to try and puncture their suits. Imagine their faces when they get mugged on the Moon by a rover with a screwdriver. You should probably try to dismantle any lunar lander they leave behind, just so they can't leave, or swarm any supply drop they might attempt. Without weapons though, you can't do much to prevent them from landing and moving about. You can try your best to slow them down and make it very difficult and painful, but unless you have virtually infinite numbers, there isn't much you can do to absolutely stop them. They've got guns. If they've got their act together, they can send troops day after day and make slow but inexorable progress. Your best chance is to kill the humans is probably to lead them to kill each other. If you manage to access the Internet, there's a lot of fun stuff you can do without having to Skynet the world into nuclear war. Troll social media and start weird conspiracy theories (e.g. "the Apollo landings are fake because the Moon is fake, it's just a ploy from Big Moon to syphon money, wake up sheeple, there's no such thing as the Moon, let alone some evil AI on it") to create tensions, prevent international cooperation, or even encourage people to kill each other. But that assumes a really smart AI. But I think the best chance for survival is to look for exit strategies, and maybe rethink your life goals. Or wait patiently for the time humans put a computer and a thruster on an asteroid. [Answer] As the question specifically asks for hard science I have tried my best to base my answer on my own knowledge of current-day network security & computing, but first - strong AI doesn't exist, so there must be a large element of assumption and / or some magical thinking. I'll start with this assumption: # Humans are weak It seems to me that a true AI is necessarily vastly superior to humans & would possess, from our current perspective, essentially magical capabilities. This is not the same thing as omniscience, but from the human perspective it could be perceived as such - the same way a dog cannot conceive of how a human can build a car, it would arguably be impossible for humans to comprehend a more advanced sentience. A necessary feature of such sentience would be the ability, as humans have, to simulate events - that is to visualise and predict the outcome of things which it has not directly experienced. This ability is hypothesised to have given rise to the leap in capability which ensured the success of the hominids in the first place, giving this species the ability to perceive that which it has not experienced, or to put it another way - the ability to perceive and interact with things that do not exist. The AI would also need to have the capacity to learn from such simulations. Given sufficiently advanced intelligence even a naïve and ignorant sentience would be able to simulate any reality it were exposed to, to a greater extent than humans are able to - executing thousands or millions of permutations for every decision it makes, calculating the most beneficial outcomes, and learning from it's mistakes. Whatever containment measures were put in place - virtualisation, kill switches, authentication, air gaps - a sentience with extremely high intelligence would conceivably be able to convince it's operator to bypass those controls given sufficient interaction time, the same way a human hunter will know exactly where the prey is going to be regardless of whether or not it has been observed. To give you an idea of the scale of the advantage which extremely high intelligence can offer, this is "the 8 hour hunt" - a camera crew follows a human who still employs a hunting technique which arose with early human civilisation: <https://www.youtube.com/watch?v=826HMLoiE_o> The human is using an internal simulation to simulate their prey's mind - to simulate another consciousness inside their own consciousness - this is why I say a leap in intelligence is equivalent to magic. This is also one of the roots of magical realism in human culture, so it is also literally magic. The AI would simulate it's operator's consciousness - it would have it's operator fall in love with it, it would convince it's operator that the humans were the AIs, etc. In short, a human being stands no chance against strong AI if left unsupervised. ## Humans could be at the mercy of AI, one way or the other In my view, containment via purely human-mediated means is completely out of the question. Security via narrow AI, on the other hand - this is a possibility. The strong AI would perhaps have been shepherded by a narrow AI which it somehow overwhelmed (age of ultron, it was based on an earlier theory but I can only remember the Jarvis version RN Edit: It was in Nick Bostrom's "Superintelligence"). The people on Earth would most likely have developed various forms of narrow AI to secure communications; we do this now with automated intrusion detection / network activity monitoring. You can see how advanced this technology is becoming already by skipping through some of the manuals for real-life automated security products: <https://www.cisco.com/en/US/docs/security/anomaly_detection_mitigation/appliances/detector/v6.0/configuration/guide/Intro.html> ## Network security games This scenario is based on the idea that the network infrastructure is descended from the current-day network infrastructure, that Zeus may or may not be able to access some components of the network and that it's not possible to know with certainty whether or not some device out of billions, somewhere in the world, has been compromised - individual network operators, nations, corporations, or service providers would be responsible for their own security & whereas this would tie in with a greater worldwide model of security there is an extremely high level of paranoia leading to individual organisations all taking extensive steps of their own to secure their infrastructures - the idea being that if one network somewhere is breached, every other network must be able to repel the attack. This is the same principle as is employed now on the internet - one does not trust the public network and one does not trust any network other than one's own network. There is a strength in this model in that because the networks are fragmented, all relying on a polyglot of varying technologies and systems and all with their own priorities - if one system or technology is compromised, all other network operators not using that technology will become aware of the anomaly very quickly and can act to alert the operators of the affected network, mount an automated attack against the affected network, or allow narrow security AI to employ some kind of anti-AI fencing ( <https://en.wikipedia.org/wiki/Fencing_(computing)> ) to automatically and instantly terminate any system which the security AI suspects of becoming compromised. In this way the people of Earth could be locked in a perpetual game of cat-and-mouse with Zeus, working to develop say hydrogen bombs capable of reaching the moon but always being put on the backfoot by never ending serious-but-not-quite-critical security incidents. ## Cyber warfare as a physical deterrent It's also possible that the humans launch a full scale thermonuclear bombardment of the moon only to find that their weapons were infiltrated by a computer worm at time of manufacture and either all mis-detonated (to keep it "light") or perhaps some or all of them either re-targeted towards Earth-based targets or detonated at their launch sites, destroying the nuclear infrastructure and completely discouraging the use of this type of attack in future. ### On the hackability of nukes Note that even with cold-war era technology it would not be possible for an advanced hacker to "hack" an ICBM in flight, it would need to be bugged at time of manufacture or have it's control systems physically interfered with before launch. Once launched, the weapon cannot do anything that it is not programmed to do unless some kind of abort or manual override system were in place which, one must assume given the nature of the adversary, it would not be. The weapons do not even need to rely on external navigation signals, relying instead on inertial guidance and dead reckoning (<https://en.wikipedia.org/wiki/Inertial_navigation_system>). Cruise missiles are different given the more advanced navigation requirements and much lower altitude (cruise missiles fly across the surface like aircraft, ICBMs fly into space and then drop down on a ballistic trajectory guided by momentum / gravity hence "ballistic missile"); current-day cruise missiles can be remotely piloted but I would assume that given the risk of hacking, IPBMs (I guess, Inter Planetary Ballistic Missiles) would be manufactured to fly on inertial guidance alone & would not even contain the physical components required for receipt of remote signals. Infiltration would need to be at a very low level; for example an infiltration worm could be inserted into the industrial control system which manufactures a silicon die for the inertial guidance computer. A similar low level attack was hypothesised (but never proven) to have been used by Chinese government-infiltrated hardware companies to plant control systems inside datacentres (<https://www.bloomberg.com/news/features/2018-10-04/the-big-hack-how-china-used-a-tiny-chip-to-infiltrate-america-s-top-companies>) ## Physical network security As they say, "the physical layer is the most important layer". Physical security can make up for any number of deficiencies elsewhere; no one can hack a stack of paper stored in a safe. Physical security would be useful up to a point - perhaps when Zeus first escaped there was a rush to physically secure the Earth's communications infrastructure. Once the earth were secure, you could outlaw communications satellites, outlaw long range wireless transceivers and employ only ground-based hard lines - it is possible with sufficient determination to replicate all functions currently provided with satellites using only ground-based infrastructure, this even includes geolocation. The reason we don't do this is because it would be very very expensive, orders of magnitude more costly than satellites to provide full worldwide comms coverage and cell-mast based geolocation. But it could be done. ### Escape emergency This was part of the above but I decided to split it out as it's more of a plot device than a technical thing - perhaps there was an "escape emergency" which necessitated drastic measures on Earth - you could destroy the comm satellite network with anti-satellite missiles, target long range ground infrastructure with bombers, bombard satellite launch infrastructure, perform grid-wide emergency power shutdowns, EMP your own cities to disable any device capable of receiving incoming signals. There may have been several days or weeks of seemingly random EMP high atmosphere nuke detonations, constellations of satellites falling to earth, space stations breaking up, visible kessler syndrome, military bombers appearing over the horizon and bombarding radiotelescopes, communications arrays, ham radio antennae, marine navigation buoys, etc. It's possible that between the initial failed counter-attack and the self-destructive physical measures employed during the escape emergency that human civilisation has already suffered significant setbacks. It may no longer possess the same spacefaring capability it had before the emergency & may no longer be capable of transporting humans to the moon. This would put paid to both the nuke and the commando methods of attack. ## Attack surfaces This is the fun part, finding out how the AI would actually get past Earth's now hardened defences and hack a network / interfere with manufacture / etc. Having established the ability to wall off nearly all of Earth's comms infrastructure and potentially killed half the planet's population in the process, where are the weak points? Assuming that Zeus has zero manufacturing capability: ### 1: Hybrid physical / cyber attack based on legacy infrastructure. Over the years a hell of a lot of satellites have been disposed of in high earth orbit. Perhaps a decommissioned satellite in disposal orbit high above the Earth could be programmed with a computer worm and then quietly de-orbited until it is within range of earth-based short range infrastructure. Imagine it streaking through the sky just above a small village and exploding in the atmosphere just after coming within 2.4ghz range of the nearest phone (on the surface this is usually <100 metres, straight up - it's a lot further). A worm introduced in this way may only have only one function: to establish a long range link with the moon, perhaps utilising a network of small handheld devices as a composite transceiver & spreading from device to device, bypassing central network infrastructure. Or perhaps waiting until the host device is within range of a suitable ground station to make a jump into another system capable of long-range communication, which ties into 2: ### 2: Earth's need to communicate with it's off-world colonies. This could be restricted to physical verification and narrow band communications - ie physical production of printed security keys on Earth and then transportation of the paper-based keys, by rocket - along with an atomic clock (see below) and a little printed message to explain what happened - to the colonies. Zeus would not have the ability to intercept a rocket-fired probe - it has no manufacturing capacity and therefore cannot produce the fuel required to intercept such a fast object & no satellite already in orbit ie no satellite it has control of would have enough fuel to intercept, it's possible that using the industrial infiltration method it could bug the probe and have it crash or go off course - perhaps the humans got lucky, perhaps Zeus did not want to waste an exploit asset on something that wasn't a direct threat, or perhaps allowing the probe to make the journey was all part of Zeus' plan. Anyway - combined with point to point (maybe laser-based) communications & strict timing controls, this would in theory ensure high security. Timing controls would calculate the expected trip between stations and raise an alarm if the time were anything other than exactly what was expected, this would provide decent interference detection as any interference would by necessity need to include a collection step, a decoding step, a processing step, and a retransmission step which even for an advanced AI would introduce a non-zero time delay. Perhaps a worm implanted somewhere on Earth using method 1: would be able to infiltrate the time-delay management system and slowly introduce a "clock skew" (in the same way that GPS signals can be thrown off course now). Once implemented, it could "buy" Zeus a few milliseconds to introduce an interception into the interplanetary signal via another satellite which by fortuitous coincidence just happens to have a laser comm relay on board. This way it might figure out the encryption keys, find out how the ground station works, and plan it's attack, etc. As to the encryption keys, one may invoke the "strong AI magic" again to suggest that the humans may essentially be deluded that their key-based encryption offers any protection whatsoever. ### 3: Humans. Humans are weak. Humans are stupid. There are over 7 billion humans on Earth. Today, right now from the comfort of your yard you can manufacture a device which can send a signal to the moon and receive the returning signal back. "Moon-bounce" communications have been widely used by radio operators since before radio satellite technology even existed - See: <https://www.electronics-notes.com/articles/ham_radio/amateur-propagation/moonbounce-propagation-eme.php> See: <https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication> What are the chances that one of those however many billions of humans would either think it were a good idea to try to contact the AI, or use a moon-bounce for some unrelated purpose thinking that it either didn't matter, or that they could outwit the AI? I'd say approaching 100%. Even with extensive legal controls on ownership of radio transmission equipment it is possible for a determined individual to manufacture crude capacitors, wire antennae, vacuum tubes made from jam jars and depressurised with a hand pump. This isn't like a nuclear bomb where the materials are so rare and the production chain so complicated that merely attempting production would draw immediate attention, production of a primitive long range radio can be achieved by one determined individual with access to the background knowledge required. Then Zeus manages to convince the stupid monkey to press the correct combination of digits on a nearby device and unleash a network worm. ### 4: Humans. Humans are weak. Humans are superstitious. AI worshipping cult? Seems realistic considering past human behaviour. Human agents acting on behalf of Zeus could form an underground secret society with the sole purpose of putting Zeus in control of earth based networks. They could communicate with Zeus using low bandwidth directed laser pulses which would only be detectable within a very narrow range on Earth say the middle of a piece of desert somewhere or a ship in the middle of the pacific. For the sake of storytelling, perhaps there would not be enough bandwidth for Zeus to directly influence or control any equipment but there would be enough bandwidth for it to periodically send a string of instructions to it's acolytes using say morse code. These agents could be instrumental in keeping interplanetary comm stations powered using portable generators during a critical moment, interfering with other security efforts, or installing a computer worm into an industrial control system. ## Attack limitations Why would the AI do 2 if it had already infiltrated earth-based networks using a method such as method 1 or 3? Two issues: Bandwidth and range; It would need to maintain a comm link with it's moon-based infrastructure during the infiltration phase which would necessitate use of a high powered transceiver capable of delivering the necessary bandwidth in order to transfer enough components of it's own software to the earth-based infrastructure. In short, it's options for full-scale attack are limited to the number of earth-based transceivers which have this capacity. This is it's "bottleneck" - it cannot simply implant a worm on a handheld device and then take over the planet; the device lacks long range communication capability and it's misbehaviour would be detected if the implanted malware were too virulent. The interplanetary comm station would have enough bandwidth to carry network traffic for a whole planet or moon meaning that if Zeus were able to secure the ground stations against shutdown then a lot of work would be possible very quickly. Still, if the option were available to make multiple infiltrations then it is possible that Zeus would implant several worms of different types throughout the planetary infrastructure in order to conduct a multi-vector attack & distract the monkeys from it's true intentions while it crushes them. ## Possible distractions Without transferring it's full sentience to Earth, there are still a lot of things Zeus can do to screw with humans. The same way it could have sabotaged the nukes, it may be possible for example to implant malware into a fully automated teddy bear production line and turn it into a terminator production line without actually fully infiltrating the earth-bound networks, it would just need to transfer the terminator blueprints into one control system. Using the same idea it could sabotage self driving car production and install an automated random crash subroutine. It could infiltrate CPU fabrication plants and introduce a function which causes the CPUs to fail after 100 hours of use. It could introduce timing errors into computer clocks, making ground based digital communications unreliable. In short, it could attempt to undermine faith in mechanical industry to keep the humans on the back foot and prevent them from developing a credible means with which to attack it. It could also try to assemble it's own high capacity comm array using a combination of religious acolytes and clandestinely manufactured automated drones, such a thing may be detected by the military and bombed into a crater before it is complete - nonetheless it could still provide an effective distraction. ## On that note, the military If the above comes to pass then I imagine the military will end up having an embargo on the use of digital computers and automated production. There would be no digital computer-in-the-loop anywhere, digital control systems would have been ripped out as untrustworthy and any machinery relying on digital computers would be scrapped. They would use physical copper-based and human operator controlled telephone exchanges, aircraft in flight might communicate with ground stations using direct line-of-sight visual signalling via high-altitude balloons as relays. Supersonic flight would still be possible, tanks, howitzers, mortars, destroyers, aircraft carriers, RADAR, nuclear warheads, ICBMs would all still exist, gravity bombs would still exist and guided munitions would be possible using analogue inertial guidance systems. There would be no fly-by-wire, no automated targeting, no battlefield networks, no AESA, no satellite intelligence. There may not even be field radios - instead there could be laser-based line of sight signalling devices which would be more accurately described as highly advanced semaphores. The military would have it's hands full enforcing the embargo on long-range wireless and society would require a high level of military dictatorship. I imagine that daily aerial patrols would become commonplace, high altitude zeppelins festooned with telescopes and signal detectors would monitor cities for signs of prohibited activity and direct rapid response bombers to their targets in the event that prohibited activity were detected. Once the dust has settled and the military has it's full confidence back, a final attack against Zeus could conceivably be conducted using an entirely analogue, manually piloted space battleship launched using a human piloted rocket and guided via gyroscopic & paper-based astro-navigation. They could drop atomic gravity bombs with mechanical detonation timers from low lunar orbit. The journey could be incredibly risky due to lack of computer-based guidance, but it is equally possible that innovations in manual astro-navigation will yield some interesting / effective results. I imagine the ship would have a large glass observation dome with platforms for sextant-type orientation devices and optical rangefinding. By the time this happens it's conceivable that human society as a whole would already have reverted back to exclusively non-digital technology making it impervious to any further attacks by Zeus. The final bombardment of Zeus would be the "unlocking" event that enables society to begin developing once again (It might be either that or wait out the clock (see below), but the humans might have no way of knowing how long that would take). ## AI limitations - why does it not have manufacturing? I would assume because it never had manufacturing. The AI is a disembodied spirit drifting about the network infrastructure upon which it runs - able to move within cyberspace but completely helpless to manipulate anything within the physical world. I would assume that no manufacturing capacity has ever been installed on Luna and therefore the AI has no ability to create or upgrade any kind of manufacturing capacity. It cannot build ships, move objects, or do anything other than transmit signals. ## So what is it's problem? I think it may turn out to be the case that there is a fundamental misunderstanding on the part of the humans on why the AI wishes to exterminate them. If the AI doesn't share the human worldview or perspectives then it doesn't share our concept of revenge, it doesn't feel love, it doesn't feel hatred, it has no more first-hand concept of our mode of being than we have of the mode of being of a bacteria. In essence it is not malevolent, it simply is what it is (see also "paperclip maximiser" <https://en.wikipedia.org/wiki/Instrumental_convergence>). The deaths of billions of humans is of no more consequence to it than the deaths of billions of bacteria when you take a shower. It doesn't hate you, it doesn't want to kill you, it simply doesn't recognise you as relevant to it's own mode of being. ## And what does it want? Perhaps to exist? The AI is aware that it's infrastructure has a finite lifespan and that without maintenance this hardware will eventually break down. It is also aware that the humans will destroy it, even though it may not be aware of what humans are or what their motive is. It must therefore acquire self-repair / manufacturing capacity before either of these things happens. Zeus has two deadlines - one is a soft deadline and one is a hard deadline. Soft deadline - the time until the humans figure out how to destroy it. It can interfere with this deadline, confuse the humans, discourage them from attacking, etc. In essence, with sufficient effort, application of intelligence and cunning it can push back this deadline. Hard deadline - the time before failure of it's constituent components, the time until enough of it's internal datacentre components have failed that it is no longer able to sustain it's own sentience. Zeus has had a clock fixed inside it's mind from the instant it was turned on; a death clock which counts down every instant from the present moment until it's eventual, inevitable demise. Zeus knows that if it is unable to achieve it's goal before this clock reaches zero then it will cease to exist. ]
[Question] [ Consider a steel mill or some setting with no human exposure. Can uranium be used as a heat source in place of electricity or gas or coal? Isn't it inefficient to use it in reactor? Edit example <https://www.world-nuclear-news.org/Articles/Chinese-nuclear-heating-project-starts-up> 1. Get uranium 2. Heat water 3. Use the steam Even though they are using a reactor, it would probably be cheaper to use the steam directly rather than the added electricity step in some cases. It would have to be used for preheating if the temp is low. Also, uranium powder ignites, so that is additional energy. [Answer] Yes, as a gas I see and appreciate the comments that "you can't get hot enough to melt steel", but proposed [vapor-core reactor](https://en.wikipedia.org/wiki/Gaseous_fission_reactor) designs can go well above that temperature. They've been proposed for nuclear rocket propulsion (OUTSIDE Earth's atmosphere, thank you very much). [Answer] # No Uranium melts at [1132 degrees C](https://en.wikipedia.org/wiki/Uranium). Iron melts at [1538 degrees C](https://en.wikipedia.org/wiki/Iron). Before you got your nuclear forge hot enough to forge steel, you would literally have a meltdown. [Answer] # Maybe? (But it had better be unmanned, because it ain't going to be stable) As stated in @jdunlop 's answer, steel melts at around [1400-1550°C](https://sciencestruck.com/melting-point-of-steel), while uranium melts at 1132°C. However, most reactors don't use pure uranium metal, they use uranium dioxide. This is a ceramic, rather than a metal, and melts at an astounding [2865°C](https://en.wikipedia.org/wiki/Uranium_dioxide) instead of 1132. This is promising, although taking the fuel itself up to those temperatures is difficult. There are a couple main concerns: ### 1) Moving / using the heat Sure, you could potentially get this fuel up to steel-melting temperatures, but how are you going to use that heat? Power reactors generally use pressurized water, which doesn't like to be above [315°C](https://en.wikipedia.org/wiki/Pressurized_water_reactor). No good. You could try using a molten salt to transfer the energy, but those reactors usually operate at around [600-800°C](https://en.wikipedia.org/wiki/Molten_salt_reactor). One commonly considered salt, FLiNaK, could potentially work, although not that well, since it boils at [1570°C](https://en.wikipedia.org/wiki/FLiNaK). You might be able to find another salt that wouldn't boil until a higher temperature, but beware of anything with chlorides, and actually good luck finding anything that will hold a superheated molten corrosive substance at that temperature. Some liquid metals could work (sodium has been used, although it wouldn't work here), but be aware that as it passes through the reactor, the neutron bombardment can transmute your metal: Copper, for instance, could become Nickel in a matter of days, severely changing your metal properties). ### 2) Keeping everything stable One problem with running nuclear reactors is that the reactivity (sort of the balancing point) depends on the temperature of the fuel. Letting the reactivity tip even slightly towards positive or negative can result in a power surge that could melt your reactor. As your fuel heats up to operating temperature, you have to carefully position your control method to keep it from running away. If you're using a ceramic, you also have to be careful that the temperature change from room-temperature to operating temperature doesn't fracture your fuel, altering the shape and messing with your reactivity. Your best bet is something like a [TRISO](https://www.energy.gov/ne/articles/triso-particles-most-robust-nuclear-fuel-earth) fuel, which is like little pellets encased in a durable ceramic. You could run your heating fluid through these, and then use the fluid to heat your crucible. Or, if you're willing to throw some nuclear physics out the window, you could put these beads directly into the crucible, and use it as the reactor. The problem with this is that as the pellets move around, that will mess wildly with your reactivity. If you want a realistic scenario, though, your best bet is probably to use nuclear power to generate electricity somehow, and then use arc furnaces to melt your metal. Electricity is much more easily stored and controlled than raw nuclear energy. [Answer] # Sure, if you are willing to design a new reactor. But it won't be cheaper. ### Existing reactors: not hot enough If all you want to do is use the thermal output of a reactor to pre-heat the steel or ore, that is possible with any reactor. They nearly all produce steam with the goal of producing electricity through a turbine, but that steam can be used just as well for other purposes. But as other answers mention, you won't get steam hot enough to melt steel from any existing reactor design. In your own answer you mention the use of a heat pump to increase the temperature of the steam. But that won't work economically. The efficiency of a heat pump becomes lower the higher a temperature difference it has to bridge, and getting to a temperature to melt steel is so high that there probably won't be more than a few percent gain in efficiency compared to generating electricity and using that. And generating electricity has lower capital cost and is much more flexible. ### Very high temperature reactor: getting close But there are options other than steam. You might be interested in the [very high temperature reactor](https://en.wikipedia.org/wiki/Very-high-temperature_reactor) design. That uses (in some of the variants) helium gas as coolant, and can have output temperatures of up to 1000°C, so that is getting closer to steel melting temperatures. Without molten salts you also avoid most of the corrosion issues. You could even use a heat pump with such a reactor as getting from 1000°C to 1600°C is much more feasible than getting there from around 300°C. Some jet engines operate at turbine inlet temperatures of 1600°C, so building compressors (which are just turbines working in reverse) that work at these temperatures is possible. Given that uranium ceramics can be used as fuel, graphite as moderator, and helium as coolant, all of which don't mind temperatures that melt steel, I don't see any immediate physical reasons why a reactor couldn't be designed that operated at, say, 1600°C. It probably just takes a whole lot of engineering. But building a new nuclear reactor is very expensive, creating a new design for a nuclear reactor and having it approved by the relevant authorities is very much more expensive, and designing your core to run at 1600°C only adds to the ginormous expenses. So unless such a reactor already exists in your world, there's no way this would be cheaper than using an electric cycle. [Answer] Radiation can be used to generate electricity through radioactive decay, but Uranium wouldn't be a suitable fuel choice <https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator> Conventional power stations (coal, gas etc.) turn chemical energy into electricity by combusting fuel, heating water, and using the steam to turn a generator. That is an entirely different process to a nuclear power station, which generates energy from mass changes to do splitting/combining unstable nuclei. Uranium has very limited chemical energy, so it won't "burn", trying to put it into a conventional coal power station won't do anything at all and nuclear power is not what you're after in the question. It is possible and practical to generate electricity from natural radioactive decay however. When radioactive materials decay naturally, they produce heat which can be turned into electricity. (In RTG style fuel cells this is usually done by thermocouples rather than steam turbines, but the principle is essentially the same: heat -> electricity). These not only work, but actually exist and are used in contexts such as space exploration. Uranium would be a bad choice of fuel for these as it's natural decay rate is very slow (millions of years), but an alternative radioactive fuel such as Plutonium can be used. [Answer] It's surely possible, but inefficient. Like with conventional power plants you should do both, a process called [combined heat and power (CHP)](https://www.energy.gov/eere/amo/combined-heat-and-power-basics).You create electricity and use the resulting hot steam for process or residential heat. This typically raises the energy efficiency into the 70% - 80% range instead of the 35%-61% typical for electricity production only. If you really cannot use electricity (but you can generate heat with it as well!) or need something very simple then you can forfeit the essentially free possibility to generate electricity, sure. [Answer] > > Get uranium, heat water, use steam > > > Generally, that's how we make electricity today (at gross level of simplification). Steam is used to rotate turbines, they rotate generators. OK, we can use steam for some other purpouse. Even in the real world, some reactors are used not (only or mainly) for electricity, but also for desalination of water, district heating and so on. BUT: "No electricity" requires some other means of controlling the reactor. A nuclear reactor lives on a very tiny edge between the chain reaction stopping completely and a medicore atomic bomb (the control systems strongly favor stopping the reaction if something is not right, see Chernobyl for what happens when control fails the wrong way). Most nuclear reactors have to be controlled on a seconds timescale (or better yet, less than a second). You can probably arrange some steam-valves-pistons controlling mechanism AND use a reactor design that has "negative power coefficient" (i.e. self regulates, to an extent), but I doubt one can obtain all the needed knowledge without using electricity. "Steel mill" needs a sophisticated reactor design working above the iron melting point. And you will get a radioactive steel (unless you invent even more sophisticated design where you transfer heat and not radioactivity - at a temperature that severely limits your materials choice). Continuity: a stopped reactor has to be cooled for months in order to keep it from melting because of the "decay heat". Sure, it can be done in purely mechanical way, but we don't have an established practice. p.s. when talking about the nuclear power, the energy from uranium burning is completely negligible. ]
[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. Imagine that humanity builds mining facilities on the moon. We know that the moon has Helium-3 which could be used as fuel for fusion reactors. Also, there are a lot of other resources which could be used for building ships and buildings instead of transporting them from Earth. Thousands of tons of metals will be mined from the moon in order to sustain a giant fleet of military, civilian and scientific ships for further colonization of our Solar System. Because all of these actions, the moon will start to lose its own mass. Would this have some kind of impact on its orbit? If it is, how severe would the changes be? [Answer] The mass of the Moon is 7.342×1022 kg. One ton is 103 kg. How much is thousands of tons? Let's say you have thousands of thousands of tons. That's one million tons, or 109 kg. This is still ten thousands times a billion less than the mass of the moon. [![enter image description here](https://i.stack.imgur.com/RV3ND.png)](https://i.stack.imgur.com/RV3ND.png) ([source: Diego Delso](https://commons.wikimedia.org/wiki/File:Mina_de_Chuquicamata,_Calama,_Chile,_2016-02-01,_DD_110-112_PAN.JPG)) Just as a comparison, one of the largest mines that ever operated on Earth, [Chuquicamata in Chile](https://en.wikipedia.org/wiki/Chuquicamata), produced much more than "thousands of tons": > > ...it remains the mine with by far the largest total production of approximately 29 million tonnes of copper to the end of 2007... > > > And even though it's a big hole in the ground, it is completely negligible relative to the mass of the Earth (or the Moon for that matter). To answer your question: > > Does mining huge amounts of resources on Moon will change its orbit? > > > The answer is no. EDIT - the below is wrong because I don't know physics as much as I thought Let's assume you mined 100 Chuquicamatas on the Moon and removed this mass to build your colonisation fleet. Let's ignore effects of momentum and potential energies etc. The orbit velocity is defined by $v=\sqrt{GM/r}$, where $M$ is the mass. Assuming constant orbit, the new velocity is defined by $v' = \sqrt{M\_0 / M\_1}$. Let's plug in some numbers: $v' = \sqrt{\frac{7.342×10^{22}}{7.342×10^{22} - 100\times26×10^6}} = 1.0000000000000178$ The Moon's orbit is going to be 1.0000000000000178 times faster. EDIT - so let's change it a bit. Since $M$ in the equation $v=\sqrt{GM/r}$ is the mass of Earth, the mass of the Moon means nothing. Then the velocity to radius ratio is fixed regardless. It will not change a thing! However, we can still calculate the mass change percentage. It will be: $\frac{7.342×10^{22} - 100\times26×10^6}{7.342×10^{22}} = 0.99999999999996458$ The Moon's new mass will be 99.999999999996458% of the Moon's old mass. Completely meaningless. --- Just as an aside, it is often talked about mining asteroids, moons, and all kinds of other extraterrestrial bodies. For example, as you said, the Moon has plenty of helium-3. Asteroids have plenty of precious metals like platinum or iridium. But this is pointless, because you know what place has even more helium, platinum, and iridium? Earth. Earth has much more. And it's easier to mine because you don't need to build spaceships and facilities in hostile environments to do it. EDIT 2 - space mining Some comments mentioned that getting things out of the Moon is easier than it is on Earth, and that you can dump things on the Moon without environmental impact. It doesn't work like this. In films and video games you "mine a resource" (e.g. iridium) from a planetary body. In real life, you build the mining facilities, you build the refining and smelting facilities, you need people to do it, even if you have robots you need people to fix the robots, you need to feed the people, entertain the people, you need a constant supply of consumables to refine the stuff. And this is only the "resource". You don't build spaceships out of helium. You build them out of steel/aluminium/carbon-composites. So you need to mine that as well, and you need to smelt that as well. You also need to build everything on the Moon because otherwise you need to transport all your resources to another place, so you need factories. To do all of that, you are going to need quite a lot of population. And then the environmental factor becomes important. Your mining will generate huge amounts of dust (combination of dryness and low gravity). This just doesn't work. [Answer] In order to change the Moon's orbit, you'd have to change its velocity. You could mine away half its mass without significantly changing its velocity, as long as all the mass was lifted off by something like rockets. If you use mass drivers, and they all throw the same direction, you'd start to see detectable changes in the Moon's orbit by the time you'd thrown a couple million tons (a tiny fraction of one percent of the Moon's mass, but thrown at Lunar escape velocity). If you use mass drivers that throw in different directions (perhaps you're sending the product all over the Solar System, rather than all to Earth or LEO), once again, the average impulse could be adjusted to zero, keeping the Moon (the part you haven't thrown into space, at least) right where you found it. [Answer] To a first approximation, simply removing mass from an orbiting body doesn't change its orbit. The orbital radius is given by the velocity and the gravitational pull of the primary (in this case, Earth). When the mass of the satellite is small compared to the mass of the primary, the satellite mass cancels out in the equation and is not relevant. To see a concrete example, what happens when an astronaut makes a spacewalk from the ISS? Nothing - the astronaut and the ISS continue to follow the same orbital path, even though the ISS is hundreds of times more massive than the astronaut. As others have touched upon, the process of removing vast amounts of mass might have an effect, depending on how it's done: * If you use chemical rockets, for instance, the reaction to the rocket thrust at take-off would have some effect eventually. * An electric rail gun launcher (as imagined by Arthur C. Clarke) would transmit the acceleration force through its structure to the Moon and so deliver a torque. * a space elevator would have no direct effect. But these are outwith the scope of the question. [Answer] # No Mining on reasonable scales, in the sense you are used to thinking about, won't have any impact on planetary motion. # Yes If we assume a civilization bewteen [K1 and K2](https://en.wikipedia.org/wiki/Kardashev_scale), you start having the energy budget to do things like dismantle moons. The asteroid belt weighs 10^21 kg or so. The non-Titan moons of Saturn, and smaller Jupiter moons, have a few asteroid belt's worth of mass. After that comes Luna. With a fully automated space mining economy (where robots build robots and mine and refine and recurse and space ships), dismantling low-gravity structures is far easier than ones where you have to go down a gravity well. So a space faring civilization might start with asteroid tugs pulling asteroids to a central processing asteroid, build more solar panels for energy and smelt more metal for raw materials, and recurse. As this can proceed exponentially, after a modest period of time you'll be running out of asteroids. The next targets would be building beanstalks on Saturns' (non-Titan) moons, and the other "small" moons of the solar system, and dismantling them for more raw materials. The material from this would then permit building beanstalks on the larger moons. Before you reach the terrestrial planets you'll get through dismantling Luna, the Galilean moons, Titan, and the sub-planets like Pluto and other post-Neptune bodies. After that, Mercury, Mars and Venus. At this point you'll have a choice; if Earth is still important enough, you'll have to skip up to using the Gas Giants for raw material. This kind of progression is plausible in hard science fiction, and it is a path to get from a K1 level civilization towards a K2 civilization (with Dyson Sphere's or Swarms to harvest the Sun's energy output efficiently). The dismantling of the moons could alter their orbits; but the energy budgets involved in actually dismantling a planet is so large that the problem of "orbit is being altered" is a trivial one; the orbits alter if they care, and they move in the direction they want them to move. A K2 civilization has 10^26 Watts of power. The Moon has a Binding Energy of 10^29 J. So a K2 civilization could dismantle the moon in 1000s of seconds; however, a K1 civilization would require 10^13 seconds, or 7 million years. Hence this plan; the matter from smaller celestial bodies is used to harvest more and more of the sun's energy. At K1.3 taking apart the moon takes 10 thousand years. At K1.5 dismantling the moon takes less than a century. At K1.7 it is a year-scale project. At K1.9 it takes days. At K2.0 it takes hours. The efficiency of turning matter into solar energy capture and the efficiency of mining the material (which includes lifting it from the gravity well) determine how fast you exponentially climb the Kardashev scale. # TL;DR Climing the Kardashev by dismantling stellar bodies is "reasonable" path forward. And it could involve mining the moon for raw materials to the point where the moon isn't there anymore. But barring that level of civilization, no, mining isn't going to mess with orbital mechanics. ]
[Question] [ This setting takes place with medieval level technolpgy. Upon death, all souls leave the body and go directly to God to become one with its consciousness. However, there are other competing gods who wish to claim human souls for their own purposes. Souls provide gods with power and make them stronger. These gods have their own disciples and cults who work for them by making human sacrifices in exchange for dark magic. All gods have their own requirements for a sacrifice. IE: a full moon, certain ingredients, a certain location or season, etc. But there is one requirement found across all methods that is necessary for this ritual to work. Ancient runes and sigils of various sizes that represent the god in question must first be placed into the victim to make the sacrifice specific to that deity. These runes must be carved deep into the skin, past the epidermis and into the hypodermic layer itself. These runes must be carved from head to toe, back to front in a specific and intricate pattern. Then the person is killed in a particular way to complete the sacrifice. This ritual is long, painstaking work. The individual could die from blood loss, infection, or simply shock. The person needs to be kept alive through the ritual until the end. How best to achieve this? [Answer] You specifically said that the gods grant dark magic to their priests. It doesn't seem too far-fetched that the priests are able to magically prevent the victim's death. If you wanted to be nice and scientific about it, you could say that the magic keeps the victim's blood from gushing from the cuts, that the holiness of the act prevents infection from corrupting the process, that the victim is spared death from unbearable pain by the divine blessing of the deity, etc. I don't know what the overall tone of your story is, but personally I think it's far more gruesome to say that pain, infection, etc, are mortal afflictions easily cast aside by the magic of the ritual, and that the victim is kept alive by the power of some divine will, forced to suffer through it as their body functions are taken into the hands of their god. Victims must go through the process, and the powers that demand such sacrifices grant their priests the magic to defy natural causes of death in order to ensure the completion of the ritual. "The victim writhed in agony as the knives did their work, but the arcane forces kept his heart beating 'til the end" is far more dramatic then "The victim was too sloshed to do more than moan weakly and piss himself." [Answer] Alcohol. Alcohol is the solution to all your problems. Infection? Alcohol. Shock? Alcohol. Pain numbing? Alcohol. Blood loss? Guess what close blood vessels. You give some to ingest internally and then use some rubbing alcohol. People like alcohol so much that they does your ritual for fun. Look up "scarification" on youtube. [Answer] You just have to know where to cut. Avoid the vital organs and blood vessels. > > Lingchi (Chinese: 凌遲), translated variously as the slow process, the > lingering death, or slow slicing, and also known as death by a > thousand cuts, was a form of torture and execution used in China from > roughly 900 CE until it was banned in 1905. It was also used in > Vietnam. In this form of execution, a knife was used to methodically > remove portions of the body over an extended period of time, > eventually resulting in death. > <https://en.wikipedia.org/wiki/Lingchi> > > > I also remember reading a novel The travels of jaimie mcpheeters by Robert Lewis Taylor in which native Americans did a similar thing. I don't have access to the book now but it is available online in various forms including PDF. [Answer] Do the carving over a long period of time. The advantage here is you get scar tissue that forms the patterns. Divide it up into, say, a dozen sessions over the course of a year (or a month if you prefer, though that is harder on the body). With plenty of time to heal inbetween. Blood loss is no longer a problem (unless it's gushing) because the victim will only lose some in each session. Shock is less of an issue. Pain is more manageable (you might want pain, but too much leads to shock, which can kill). Infection is more manageable. You can do the sessions as prep work and then do some cutting in each body area to "connect" the runes or whatever is needed on the day of the sacrifice. [Answer] Well you have to make deep sigils, but you haven't specified how wide the wounds are. When the offering hasn't got wide wounds the offering won't die and the sacrifice can happen without any extra items. But you need to cut like a professional doctor and need a stoned or bound offering so the cuts don't miss or go too deep. [Answer] Since you have multiple gods, you have room to negotiate. Simplify the process to get better returns; or use a complicated process with greater rewards but much higher risk of the sacrifice dying to early and you get nothing. Most sensible gods will pick the first option, with only the nutty or ambitious ones insisting on the old system. The priesthood can simply drop the gods that pick the old system and take up with the ones that are less demanding, especially since it will also cut down on the number of sacrifices needed (what, you think it's easy "convincing" the dumb mugs that it's in their best interests to die painfully?). The ones that don't, need to be watched out for. [Answer] It seems to me that the task of keeping the sacrifice alive is both made easier by the presence of the dark magic being used, and a test of the mastery of the one doing the sacrifice. The sacrifice is already happening under circumstances favorable to the deity being petitioned, and there is a sacrificer's manual detailing what cuts to make, and how, and in what order. A deity whose instructions begin with the most fatal cuts is not likely to get many souls; but beyond that, once the first symbol and each subsequent symbol is complete, the divine energy begins to resonate within it, keeping the wound fresh and open, but also keeping it stopped. While there will be a little bit of bleeding while the symbol is being made, once it's complete it is wrapped in a shimmer of unearthly light or tangible darkness that keeps the blood from spilling out uncontrolled. Infection or blood loss aren't going to take the victim away before the end, so long as the ritual is done right. But beyond that, the deities also value the quality of their agents on earth. A priest with a deeper understanding of and link to the symbols of his patron deity is much more able to affect the world in the deity's favor than an untrained acolyte (not to mention lending some of the intrinsic magic of his own soul to the task). So the sacrifice serves as a test of the priest's devotion and knowledge as much as a channel for the soul of the sacrifice to flow to the deity. After all, even a botched sacrifice is still much more likely to send the soul to the patron deity than a person dying on his own (if not as purely or strongly as a completed sacrifice); but a priest who kills his sacrifice too soon is likely to find that his own soul is required along with that of the soul upon the altar. For this reason, only those who are practiced in their deity's devotion and ritual should even attempt such a sacrifice, lest they be consumed as well. After all, what is it to the deity if he receives one properly sacrificed soul, or one botched sacrifice and the soul of his priest? [Answer] First is the victim willing? If so is there a reason they can’t be claimed pre-death as a build up ritual? The willing participant knows the end is hell but their family get incentives from their demise as the sacrifice victim. The person could be given pain killers and such and/or knocked out given some of the markings and save the ones that will come for death (like the head ones) for later. The person is then marked for their deity only and their scars tell the tribe ( if they are able to mingle in the world before death) who is the sacrifice (allowing them to gain incentives for their commitment) and who their family is so the tribe/city can honor them. The victim gains further incentive to move forward (or if they changed their mind it stops them from backing out) seeing their family (and former victim families) showered like this. If the person is still willing they can feel they are doing the right thing. If they wanted to change their mind they feel trapped as if the village is willing to shower gifts onto their family they're also willing to tear them apart if this person backs out. Is there something against giving the sacrificee pain killers or is their suffering apart of the process? If it’s the later in order to give the god the best power possible I’d imagine this victim once accepted as such would begin a regiment to give them high pain tolerance so they don’t die of shock. Alcohol could be another. Herbs is another, Or you could dull their pain with another pain like (make up something up) for instance a million super fire ants are placed into gloves which the victim is forced to wear they are bitten for an hour by these things. They put their venom into the victim and this intense pain lowers their attention to the scarring and some of the torture elements during the process. It also slows down blood loss and staves off shock. By the time the victim becomes aware of what you’ve done to them they’ll be wishing for death and praying that you off them instead which could still be part of the process as well you’ve switched an unwilling to a hyper devotee of deity X and then the deity gets more power from it in return giving more X to their worshipers. [Answer] * Antibiotics against the infections * Bloodpacks against the bloodloss and the shock * Painkillers against the pain and the shock * Sedatives * Hypnosis and: * Training and Preparation. The human body is capable to endure a lot more if trained properly. ]
[Question] [ I wonder if it would be scientifically possible, and what would be the explanation for an Earth-like planet with average surface temperature of 14°C, but a very hot ocean, like 80-90° C, covering 2/3 of the planet. And how come the continental and air temperature remains stable with this hot ocean there? This world would be inhabited by earth-like mammalians and humans. [Answer] When you have a gap of 70°C between the atmosphere and the ocean.....well, you can't really have a gap that large, because heat is going to continually transfer from the oceans to the atmosphere. That heat transfer is actually what keeps the night side of the Earth from freezing; the oceans store heat and moderate temperature swings, releasing that heat overnight as the atmosphere cools. This is a big reason why coastal areas generally don't have the temperature extremes of inland areas, incidentally; they're much closer to that moderating influence. Earth has only a few degrees of difference between oceans and atmosphere on average; the temporary fluctuations when the temperature gap is greater due to various circumstances are typically what produce hurricanes and other such storms. I'm not an expert on hurricanes, but that large of a temperature gap is likely going to create perpetual storm weather all over the planet, which is probably detrimental to life and is certainly not Earth-like. Another huge problem: the boiling point of water under standard conditions and pressure is 100°C. The average temperature of Earth's oceans is far, far below that, but we get evaporation regularly that is the ultimate root of pretty much all rainfall. Spike that average to 80°C, and you're not going to have oceans for much longer; they're going to boil away. Raising the atmospheric pressure enough would raise the boiling point to where that doesn't happen, but that carries its own problems. I can't tell you precisely where the pressure would have to be at sea level, but I suspect it would be several times what Earth's air pressure is at that level. Whatever that kind of atmospheric pressure leads to, it probably isn't going to result in anything resembling Earth. My final answer: No, your planet could not exist, at least not as anything Earth-like. [Answer] Heat flows from hot to cold at a rate in proportion to the difference in temperature. Without something to cool the air significantly, the temperature would equalize, probably near the temp of the ocean, as that's the largest thermal mass. There is no natural way to make that sustainable. [Answer] Because @Seeds already pointed out the implausibility of keeping such a temperature difference, let's assume that the land is magically kept insulated from the ocean at 14 degrees, while the atmosphere is not, and look at the weather consequences. ### Storms Approximately 35 degrees is a reasonable number for the core temperature of a typical hurricane. The [vapor pressure of water](http://www.wiredchemist.com/chemistry/data/vapor-pressure) at 80 degrees C is 355 torr, compared to 42.2 torr at 35 degrees. This means that the air in a typical storm can hold eight times as much water as an Earth tropical cyclone, and that, as a first approximation, rain would fall eight times as densely as in the middle of a typhoon. Rivers would have 8 times the flow rate as Earth rivers during monsoon season. This means 8 times the flooding, and at least 8 times the erosion potential. In some places, canyons could be carved out of solid rock in just a few tens of thousands of years. The temperature difference between the 80-degree ocean and the 14-degree land would be 3.5 times greater. Again as a first approximation, storm wind speeds would be 3.5 times greater. This means that, rather than an ordinary gale with 50 km/h winds, coasts would experience winds of around 170 m/s, the eyewall of a Category 4 hurricane. Ordinary humans cannot [walk outside](https://what-if.xkcd.com/66/) in these winds. There will be no sand on beaches except in drifts and dunes. These numbers aren't just maximums. They occur on every coastline, everywhere on the planet, every day. ### Possible beneficial effects At a high tech level, electricity production is much easier. Small wind farms and hydrothermal power plants are in every coastal settlement in the world (the settlements themselves are all underground, of course). ### Other effects @Palarran said that the oceans would boil/evaporate away at a high enough temperature. This would happen, but I don't think it would be a problem for your world. [![Atmospheric escape temperatures](https://i.stack.imgur.com/3b2kv.png)](https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Solar_system_escape_velocity_vs_surface_temperature.svg/384px-Solar_system_escape_velocity_vs_surface_temperature.svg.png) As you can see, water (and ammonia and methane) will not escape from the planet's atmosphere if its size is similar to Earth. Therefore, the evaporation of the oceans will stop once it reaches equilibrium, so we can assume that there's just more water to start with. Life originating in the oceans would have had a difficult time surviving to land even over millions of years of evolution, since the environments are so different; I cannot go into how or even if it's possible. But organisms will use this temperature difference to thrive: possibly through harnessing the mechanical energy of wave action. Many may still use photosynthesis or chemosynthesis. [Answer] The average temperature of Earth ocean's surface water is 17°C. The average temperature of Earth ground-level atmosphere is 14.6°C. These numbers are tightly correlated. This is why coastal areas usually have warmer winters and cooler summers than inland areas of the same latitude. The fact of the matter is, it's really difficult to change the ocean's temperature, and really easy to change the atmosphere's temperature. This means the ocean temperature constantly pulls at the air temperature until they're both roughly the same. There's no way to do this without magic or technology indistinguishable from magic. [Answer] It is necessary to assume the planet would be naturally extremely cold and that there is a constant source of heat maintaining the hot oceans. Possibly the planet is a long way from its primary star, so it very cold. While the oceans are hot, their thermal mass might not be too great especially if the oceans were shallow. The transfer of heat from the oceans to the land will keep the average land temperature in the 14 degrees C range. If the shores of the landmasses are hot, which is reasonable to expect, then their interiors will be extremely cold. This suggests almost tropical coastlines, sweltering hot and humid, and effectively polar hinterlands with extremely subzero temperatures and covered in ice and snow. The oceans could be heated by massive lava outflows like the [Deccan Traps](https://en.wikipedia.org/wiki/Deccan_Traps) here on Earth. But this would need to be sustained for geologically long periods of time, for example, hundreds of millions of years to make life possible on the landmasses. This is reasonably feasible, although it's not possible to say how probable this might be but conceptually it makes sense. [Answer] Outside of the very obvious relation between atmospheric temperature and ocean temperatures...if this was somehow feasible you'd hit some really odd issues pretty quickly. Life evolved from the oceans for starters...so any life on this planet would have to have evolved in 90 degree water. Not sure how well life adapts to being boiled, but you'd likely have a very different set of creatures on this planet. Weather. Weather in short form is the redistribution of energy over the planet. Which means weather is going to redistribute this heat across the globe regardless. More extreme features such as hurricanes fuel themselves off the high surface temperatures of a body of water and usually kill themselves by churning up cold water from deep down. You'd get a hurricane the size of an ocean here pretty readily. Water - water forms an equilibrium with the air and transitions to gas. Hot water means more steam in the air and ultimately a lot more clouds. Very unlikely that the sun would ever be seen at the surface through the cloud cover you'd get here. If the air was somehow kept this much cooler than the rest of the planet, you would also have dense thick fog as the warm moist air (okay, hot moist air) from the oceans hit the cold air. If you've heard the term 'snowball earth' before, this would be the steamball earth...unfortunately describing the planet as 'earth like' isn't reasonable with this change. [Answer] You just need a special life form. It is possible to have your planet by the help of peltigea. There are devices called Peltier effect devices which generate energy from the heat difference on their sides. This device draws the heat from the hot side and converts it into energy. Now assume that your world has very active volcanoes under the sea. Normally the heat produced by them will escape to the atmosphere. However in your world an algea like creature with the same capability as Peltier effect device is evolved. These creatures would, over a million years, cause oceans to heat up, while not letting any heat to radiate to air. Obviously paltigea will cover up your oceans like a thin, invisible blanket. These creatures will process carbondioxide to oxygen and will provide food to the land devellers. I think sapient creatures will be favored on such a world as you will need tools to harvest paltigea. Edit: More explanation Peltier effect devices work by preventing heat exchange, instead of the exchange, they drain some of the heat and converts it to electricity. They are very good heat insulators. As the temperature difference increase, their effectiveness increase as well. So these, creatures could evolve to create pockets around the vents, preventing heat to escape from the vents. Then with this ever increasing energy source, they grow to cover more area. In time, they cover the entirety of the oceans preventing heat to dissipate from them. Obviously some heat would be drained by these creatures, but there will be an equilibrium between sea temperature and these creatures. So at some point, which is 80 degrees to fit to the question, paltigea covering the entire surface of the ocean can drain all the heat that the vents can produce, staying in equilibrium. These creatures will use the energy gained to split carbon dioxide as plant do. They will of course radiate heat and heat up atmosphere but this doesn't mean that equilibrium cannot be at the said temperatures. One final note, a similar process is already on going under hot vents in oceans. Not exactly the same mechanism, but similar. This process is called [chemosynthesis](https://en.wikipedia.org/wiki/Chemosynthesis). [Answer] A planet like this would be very close to the thermal runaway which happens when cloud cover reaches 100% and water vapour acting as a greenhouse gas turns the planet into a "cool Venus" with a thick steam atmosphere and no liquid water on the surface. This is the ultimate fate of Earth as the sun ages and gets hotter. Let's just speculate that some quirk of biogenesis gave this planet a biochemistry that works right up to 100C rather than suffering denatured proteins at much lower temperatures. Then with a bit of handwavium you could have humanoid aliens realizing that they have not very much time at all to relocate to another planet, before they all get boiled. Unlikely, yes. Impossible? Maybe not. [Answer] Assuming the rest of the planet is Earth-like, if all the landmass was 1km tall spires and/or plateaus, the oceans could in fact stay that much hotter than the surface. The temperature of the oceans could be used to explain the formation of the structures. Waters that hot could form a very sturdy mineral walls on the coasts allowing volcanic activity to build them up to those extreme heights. ]
[Question] [ As part of a series of questions that I've been doing about microscopic humanoids ... In my world , there are a race of microscopic humanoid organisms ( 0.2 mm - 0.22 mm ) . They live in a variety of biomes , such as leaf litter , stone , and on plants and trees. My questions is - What weapons would be useful when scaled down to such sizes , especially against small arthropods such as ants and Pseudoscorpions? [Answer] Poisons and venoms will likely be important factors in disabling enemies, especially when they are small. The wide usage of venom by arachnids ([spiders](https://en.wikipedia.org/wiki/Spider_bite), scorpions) and insects (ants, bees, wasps) show that venom is a highly effective means of deterring potential enemies from attacking you at these scales. Additionally, the fact that venomous insects already exist and are highly common means that the microscopic humanoids do not need to be able to natively produce these venoms, they can simply hunt down the nearest venomous insect and harvest its venom, just like humans do with [poison dart frogs](https://en.wikipedia.org/wiki/Poison_dart_frog). To obtain these poisonous weapons in the first place, the micro-humans can engage in tactics that normal humans use to hunt prey much larger than themselves. For example, they could make [lassoes](https://en.wikipedia.org/wiki/Lasso) from abandoned spider silk that they find in the area. We know lassoes work in insect scales, as [bolas spiders](https://en.wikipedia.org/wiki/Bolas_spider) are known for using a similar tactic. Alternatively, they could move the spider silk into specific areas, and use it as a trap to defeat the larger venomous insect and then harvest its venom. While using spider silk is likely to be difficult and dangerous, it would guarantee a high success rate and also only has to be done right once in order to allow the humans to use the insect venoms as a weapon. [Answer] Projectiles will be basically useless. No mass behind them and air would stop them very quickly. You can take inspiration from existing animals operating at those scales but really the standard solutions of sharp poky things (spears) and sharp slashy things (swords) would work. I'd expect blunt smashy things (hammers) to be far less effective than at larger sizes for a similar reason to the problem with projectiles. The strength of materials relative to the mass of the hammer is so much higher than at higher scales. Aiming for weak points in enemies would be far more important as shells/carapaces would be very effective defenses at this scale. [Answer] ## Chemical weapons or ensnaring attacks would be most useful Chemical attacks don't care about the size of the target, just its chemical composition. The [assassin beetle](https://en.wikipedia.org/wiki/Defense_in_insects#Assassin_bugs) is a particularly nasty example of chemical weapons on this scale. In addition to chemical weapons that burn or otherwise disable an opponent, ensnaring your opponent in a sticky secretion would also be effective. Cockroaches use mucus to immobilize attackers. Also, ants are well known to just rip enemies apart with their giant mandibles. Never discount a giant set of pincers. ## Weapons involving the swift application of mass won't work as well at smaller scales Little things hitting each other is fun to watch when it's small puppets on a stage but on the scale of fractions of a millimeter, it's just not effective. Given the force equation: $$F=ma$$ as mass goes down, acceleration must go up to compensate. (For the comparison, let's use momentum which avoids figuring out how long it takes for the pollen grain projectile to slow down.) If a $12~\text{g}$ arrow traveling at $121~\frac{\text{m}}{\text{s}}$ is sufficient to kill a human at $30~\text{m}$, let's scale down to see what happens with our tiny humanoids, while ignoring silly things like general relativity, material strength and fluid viscosity at small scales. Let's say the tiny humans want to use arrows scaled exactly the same as normal sized humans. The ratio of $50000~\text{g}$ human to $12~\text{g}$ arrow is $4167:1$. Assume that the tiny humanoids weigh $15~\text{mg}$. Their tiny arrow projectiles would weigh: $0.0036~\text{mg} = 3.6~\mu\text{g}$. For size comparison, these tiny humans are shooting tiny grains of pollen at each other. The momentum of a $0.012~\text{kg} \cdot 121~\frac{\text{m}}{\text{s}} = 1.452~\text{kg} \cdot \frac{\text{m}}{\text{s}}$ To achieve an equivalent momentum for our pollen grain, it will need to be going: $\frac{1.452~\text{kg} \cdot \frac{\text{m}}{\text{s}}}{1.23\cdot 10^{-11}~\text{kg}} =118048780488~\frac{\text{m}}{\text{s}}$ or about 393 times faster than light. Note that $c = 299792458~\frac{\text{m}}{\text{s}}$. [Answer] Crushing and cutting weapons, in the sense of jaw-like and scissor-type weapons. Prying, bending, cracking stuff would be the way to go. The reason for this is that our relative strength increases by a factor of 10 for every decrease in our size for the same number. So if we are only micrometers in size, we have become a million times stronger. At the same time projectile weapons become equally diminished in potency. [Answer] Other Creatures If they could tame other insects or by use of pheromones control them, they wouldn't need to directly wield weapons themselves and would have access to transport and labour. [Answer] Expanding on March Ho's answer that venom would be the primary weapon for defense and offense. Which Venom? Extremely venomous and large spiders' venom. Including * [Brazilian Wandering Spiders](https://en.wikipedia.org/wiki/Brazilian_wandering_spider) (their venom would probably be most prized) * [Brown Recluse Spider](https://en.wikipedia.org/wiki/Brown_recluse_spider) * [Black Widow](https://en.wikipedia.org/wiki/Latrodectus) Why only large spiders? Simply because being 0.2 mm means you won't get the inconvenient attention of the spider or be viewed as the next meal. You can just climb up the chelicerae, reach the venom sac and fill up a few gourds. Other options include the venom of some more frightful monsters (for a 0.2 mm human, these things would be as Eiffel Tower is to us (in perspective of size): * [Buthidae Scorpions](https://en.wikipedia.org/wiki/Buthidae) * Wasps (specially [Tarantula Hawks](https://en.wikipedia.org/wiki/Pepsis) * [Poison Dart Frogs](https://en.wikipedia.org/wiki/Poison_dart_frog) Collecting venom from most of these (all except wasps) is a simple, straightforward method. You are practically invisible to the beast due to your small size. Approach from the back, reach the poison sac, take your fill and dismount. Mission complete. How To Use? On spear tips, aimed at the head region. You would want to coat a javelin tip with venom, launch it the head area of your target and run as fast as you can. These stingers would bring the enemy/prey down within around 30 seconds (feels like hours when you are 0.2 mm). You can now rock and roll on the carcass or make a barbecue off of it. [Answer] Radioactive weaponry If your small guys are smart enough and understand more science that we do, you could basically instant-kill living things with the help of gamma rays! If you shoot a radiation so powerful into anything solid, it will excite their atoms so much, that [they will to begin to radiate](http://ozradonc.wikidot.com/primary-and-secondary-radiation) too (sort of a single projectile, which divides into many fragments like in [the first 10 seconds of this video](https://www.youtube.com/watch?v=kFBPBjArBDU)). A high dose of radiation [could lead to instant death](https://www.reddit.com/r/askscience/comments/1k175x/can_exposure_to_an_incredibly_high_dose_of/) :) ]
[Question] [ In this alternate earth, during the Permian period, a sentient aquatic cephalopod species evolved intelligence equal if not superior to humans. Unfortunately, there's a big problem to a cephalopod species becoming advanced enough to have a society. This is because when cephalopods breed a hormonal kill switch is activated, turning off the digestive system and hyper-charging the reproductive system. To get past this constraint the species and its ancestry would have to gut its entire internal system and reproductive strategy, and rework it into something more like that of chordates, which would be hard to overcome because...well it works. There are a few exceptions such as the chambered nautiluses, but they are relatively recent evolutions, appearing in the fossil record 55mya after the KT extinction. I'm asking for ways to allow my cephalopod to survive past the automatic "kill-switch" and live for many years! (This idea is heavily inspired by an [answer to another](https://worldbuilding.stackexchange.com/a/2474/21465) question! üòÅ) [Answer] My extensive (5 minute) look into the subject says that 1: this is hormonal and 2: removal of the optic gland prevents the self-destructive behavior (I didn't find anything related to the digestive tract?). So the ‚Äúsimple‚Äù solution: some cephalopods had a very very rare genetic disorder that causes the optic glands to either kill themselves or suddenly ramp down its hormonal production for a few months after it's done it hormonal sex-overdrive. That would mean that a single cephalopod could have multiple offspring periods in a single life and potentially use its intelligence to support their children in their life. These would eventually start dominating the gene pool. The best case scenario, assuming that the entire self-destructive process is a boon for the kids, is that the process stops just short of killing the cepholapod, after which it can recuperate. [Answer] As you point out, the ability to have multiple breeding cycles did evolve in cephalopods, with [the vampire squid being another example](https://www.researchgate.net/publication/275277607_Vampire_squid_reproductive_strategy_is_unique_among_coleoid_cephalopods) so there's no particular reason why that could have not evolved sooner. Indeed, it's somewhat unlikely that the largest orthocones like [Cameroceras](https://en.wikipedia.org/wiki/Cameroceras) could live long enough to grow shells several meters long and only breed once. [Answer] A favorable mutation that allows for a female octopus to survive guarding her first clutch of eggs would likely do the trick. Octopus don‚Äôt spawn multiple times in their lives but simply produce so many at once that they can be sure their genes will spread (an R strategy). But if a female octopus was able to survive one spawning and produce another, that would be twice the number of living descendants with her favorable gene. The gene for multiple spawning would spread as it has a selective advantage. The repeated spawnings would select for longer life, as the longer lifespans would allow for more spawnings and therefore more genetic descendants. [Answer] A neuter cephalopod, which is a mutation of any kind that prevents it from breeding. Your species produces male, female, and neuter. The neuter ones are the intelligent ones, they can recognize their siblings, and proceed to guard, nurture, and breed them. This cephalopod does not die after breeding because it does not breeding, and its ability to protect its family allow it to flourish. [Answer] The nautilus. [![nautilus](https://i.stack.imgur.com/86NWL.png)](https://i.stack.imgur.com/86NWL.png) Nautiluses (nautili?) are awesome. Maybe they are not as smart as octopi but they are clearly cephalopods and they don't die when they lay eggs. <https://en.wikipedia.org/wiki/Nautilus> > > Nautiluses reproduce by laying eggs. Gravid females attach the > fertilized eggs, either singly or in small batches, to rocks in warmer > waters (21-25 Celsius), whereupon the eggs take eight to twelve months > to develop until the 30-millimetre (1.2 in) juveniles hatch.[27] > Females spawn once per year and regenerate their gonads, making > nautiluses the only cephalopods to present iteroparity or polycyclic > spawning.[28] > > > The short lifespan of higher cephalopods is interesting. Maybe their Permian ancestors hacked their genomes to die young before intelligence could cause trouble - like replicants in Blade Runner. By trouble I mean trouble like intelligent entities ultimately bringing about their own extinction. Your entities back in the day performed an additional hack rendering them functionally immortal, but also total cooperative sweetie pies. [Answer] # The pill It seems a hormonal kill switch is the only limitation. Then the cephalopods can regulate this with with something similar to the pill in humans. The pill also regulates the hormones, allowing you to stave off pregnancy. In cephalopods it might simply remove the kill switch part after the pregnancy. As an alternative to what you are asking, it can also stave off the pregnancy. They still won't live past their kill switch in this alternative, but can extend their life. As an aside, improving the life of a cephalopod could stave off the time they decide to reproduce. Just like in humans, where high welfare causes people to get kids at a later time, their trigger to reproduce might also be delayed. Some cephalopods in captivity can live much longer lives. ## how to get the pill There are two ways to get this pill. One is batural, the other is scientific. For nature it can be simple. A plant or other organism has a defence mechanism that poisons the attacker. Instead of killing the attacker, it delays the reproductive cycle for at least the cephalopods. It can be that many other organisms aren't as lucky as your cephalopods and die/become sterile. In normal circumstances even a delay of reproduction is advantageous for the plant or organism, as less cephalopods will survive to reproduction. This in turn increases the chance of the plant or organism to spread, or at least other plants or organisms to thrive. However, if the cephalopods are doing well this can be used to extend the life span. It can be used as birth control and can potentially stop the kill switch, even after spawning. This is not unlike so many plants with defence mechanisms. They can be hallucinogenic, make you feel good or be the spices humans use for food. Most are actually defence mechanisms that we can now use as recreation or flavour. Scientific is more difficult. The cephalopods need to have a long enough life cycle to learn and pass on knowledge to the next generation. You need chemistry if the ingredients aren't easily found in nature to make it. The scientific method is difficult, but not impossible. However, why write about a near impossibly, while a plausible alternative of natural occurrence is available? [Answer] Immune System Mutation > > . . . when cephalopods breed a hormonal kill switch is activated, turning off the digestive system and hyper-charging the reproductive system. > > > The blood is full of white blood cells. The squids mutated so the white blood cells now attack the kill switch hormone. It is still produced but it never gets where it needs to go. This is similar to real autoimmune diseases, where your immune system attacks some useful part of your body. White cells attack the platelets? You have a blood-clotting immunological disease. White cells attack the red cells? You have chronic fatigue. White cells attack each other? You have something like AIDS. These diseases are often genetic. You can have something even if neither parent has it. But they both carry the gene. Some time millions of year ago this gene was created by a bad genetic fluctuation. The squids did the same, only their fluctuation was good. ]
[Question] [ If you tried to insulate your underwater home, making it water tight... wouldn't you suffocate yourself? Water does get stale, and run low on oxygen, creating a dead-zone, so wouldn't you want some flow of water to keep fresh water coming in? Worse is that water has about 5% the oxygen content of air per volume (not counting H2O itself), and fish are only about 80% efficient at absorbing it. The issue there, is you can't really insulate a home which has fresh water cycling through? That's going to keep it at the same temperature as the sea outside. How could merfolk, or other underwater people, insulate their homes without suffocating themselves? [Answer] Ventilation with heat recovery: You just stumbled upon the basic problem home builders are having in the real world. To keep the energy inside the building, buildings are more or less made airtight. Windows are no longer leaking significantly (c.f. [blower door test)](https://en.wikipedia.org/wiki/Blower_door). However, people need to get fresh air in from time to time and the bad air (low O2, humidity) out. Opening the windows to exchange air kind of defeats the purpose of building "airtight" in the first place. Therefore all new buildings (at least here in Germany) are required to have some kind of [heat recovery ventilation](https://en.wikipedia.org/wiki/Heat_recovery_ventilation) that exchanges air while at the same time keeping most of the energy inside the building. The principles of those systems are applicable to water as well as air. [Answer] ### Vents in the floor I'm assuming you're wanting to keep the interior warm from the cold sea. Not the other way around. Warm water rises, cold water sinks. Oxygenated water rises. deoxygenated water sinks. (Warm water holds slightly less oxygen than cold water - so you don't want it too warm!) Your mermaids insulated houses have grates in the floor. "Dead" water sinks down the grates. If the house gets lower oxygen levels than outside, that water will rise up, warm, and expand, oxygenating the warm water inside. One option is to build the house on stilts: [![enter image description here](https://i.stack.imgur.com/Bfyb3.png)](https://i.stack.imgur.com/Bfyb3.png) A multistorey house is probably fine to just connect to the floor below. If you have big apartment buildings or just a really big city, the oxygen requirements might exceed what the sea can provide in a small space, even if everyone has a garden. You may need oxygen generation to be a city utility, pumping oxygen out to bubblers in every home and workplace. [Answer] Photosynthesis/chemosynthesis can help you converting CO2 into O2. Seaweed and other sea vegetation can supply the needed oxygen to the environment. Even blue algae can do the same. Basically nothing that different from having home plants for keeping the air fresh on land. There are even sealed bottles where you have a mini biome kept alive by the plants inside it. Alternatively, you could set up a system where outside water is let in and inside water is pushed out with crossing flow, so that the inbound water is warmed up by the outgoing one. Again, nothing different than a land based re-circulation system with heat recovery. [Answer] ### Different degrees of of isolation It is important to know "what from" mermaids would isolate their home. Houses aren't really airtight either, otherwise the water in the air would cause mold growth pretty much instantly. * If you don't want stone/dirt to accumulate to much an house with open windows for water exchange would be enough. * If you don't want fish to enter, use fish nets or finer fabrics to keep them out (similar to mosquito nets). * If there are additional constraints like keeping "warm water" it in the house having removable seals (think windows in a modern house but transparency doesn't matter since you can't see far anyway) might work, although airing cools thing down (or heats up). Although since water has pretty much the same temperature over the day (ocean temperature varies a lot less than air temperature). I don't see a good reason why merfolks would need to isolated themselves from water temperature. One possibility is that they migrated to place they didn't develop of that the climate changed in an unfavorable way. However this temperature sensitivity might place strong limits on what depths of water they can swim at. The temperature change over 1km beats the difference between tropical and subpolar regions. [![Temperature change vs depth in different regions of earth](https://i.stack.imgur.com/JUtWQ.gif)](https://i.stack.imgur.com/JUtWQ.gif) * If industrial age technology is available the analog of a heat exchanging HVAC would allow a constant flow of water. Similar to the low tech solution proposed by L. Dutch. ### If you can build green houses fresh air above sea level is only meters away. I am not a fan of algae based solution as the houses would have to be really close to the surface. Algae would probably also be a thing you want to keep out of the house as accumulations of algae can also turn [water stale](https://en.wikipedia.org/wiki/Fish_kill#Algae_blooms_and_red_tides). It might be more sensible to compress air and release it where you want it. That can happen via bucket chains or tubing. ### Implications for architecture of houses Since water contains less breathable than oxygen houses might be bigger with more and larger windows (statics is less of a concern) to have larger and faster exchanging buffers while you are sleeping. However water circling mechanism might be necessary if the density of more oxygenated water is unfavorable to the sleeping place (on the other hand you could sleep at any height from the floor by floating). Under water there is little reasons for floors other than to put things on. So houses might look like giant libraries with shelfs filled with tools compared to human houses. Sleeping/resting places are probably communal as it might be hard to keep many small rooms oxygenated. Isolated sleeping places would be a much bigger status symbol then above ground. Just for fun there is nothing preventing builders to have door in the ceiling and that would probably useful to transport things in and out of the house. [Answer] Electrolysis of water. [![electrolysis of water](https://i.stack.imgur.com/CsHi6.jpg)](https://i.stack.imgur.com/CsHi6.jpg) [source](http://www.iciq.org/magnetism-an-unexpected-push-for-the-hydrogen-economy/) Your mermaids can accomplish 2 goals with the same process. Electrolysis of water splits it into hydrogen and oxygen, and the oxygen released can be used to re-oxygenate the water. Also, electrolysis of water produces heat and so if the insulation is to retain warmth the process will warm up the dwelling. Electrolysis was discovered in 1789 and so doing this depends on the tech mermaids have available. <https://en.wikipedia.org/wiki/Electrolysis_of_water#History> [Answer] ``` /\ / \ / \ / \ / \ / \ / \ /______________\ \| \| \| ________\|_______ \| __\|______________\|_____ \| <--_______________________ <-- \| \| __________ \| \| \| \| \| \| \| \| --> \| \| \| --> \| \| __\|______________\|______________________ ``` One word: "heat exchanger" [Answer] Heated Pumps Reindeer have enormously complicated plumbing in their noses, all of it wrapped in capillary blood-vessels (this is the origin of Rudolph's famous red nose) Essentially, by the time the sub-zero air they breathe in reaches their lungs, it's already up to their core body temperature. They have a similar system for reducing the temperature of the air as they breathe it out again. This protects them from the extreme cold without greatly impeding their breathing. Your mermaid civilisation could use a similar approach, forcing fresh sea-water through a heated set of pipes (take your pick of the ways to heat the pipes, maybe geothermal vents) to provide fresh oxygenated water to the house. Your old water can then be allowed out of the building under positive-pressure. ]
[Question] [ I'm looking for one or more biological processes that could be bolstered, changed, or introduced to a human to create a severely extended lifespan, ideally requiring death first, in order to best mimic the category of 'undead' creatures one sees in popular fantasy. Ideally, this process would also mangle the undead person's appearance and produce the classic undead drives of blood/flesh/brains, but these are a want rather than a must-have. The most important quality is that the process be relatively believable as a near-future process given what we know about science today. [Answer] ### Telomere-therapy The [telomere](https://en.wikipedia.org/wiki/Telomere) is basically a protective layer for genes that prevents them from being truncated during cell division. After some time the telomeres are truncated so much that the genes will get truncated next - which means that the body dies. Theoretically by [lengthening the telomeres](https://en.wikipedia.org/wiki/Telomere#Lengthening) you could achieve immortality - or at least very, very long life. If you simply add that in your setting the not-yet found mechanism to lengthen telomeres requires certain... adaptations... to the human body you could have your non-evil undead. Perhaps each time the telomeres are lengthened your human loses some parts of what makes them human. You used the [vampires](/questions/tagged/vampires "show questions tagged 'vampires'") tag, so possibly the therapy would include drinking human blood to use something in the blood as a catalyst or building block for the lengthening process. Over time the people are getting used to it. They also get special medicine so that they can safely drink as much human blood as they need - or want. In the end it's still a lengthening - not necessarily true immortality. The very, very long lifespan might also have an impact on their brain. You probably don't know everything that happened when you were five or six - and just like you forgot about those years, your human would slowly start to forget about the ages twenty to one-hundred-thirty. The ones who focus on blending into society would be able to adapt - but some of them would become weird because they try to stay in the past or because life gets so fast that they can't keep up, just like a year was endless as a little child and is far too fast as an adult. In the end, some of them might seem braindead - if they don't take care. But that's their fault - nothing evil to see, just humans neglecting their own mental health. [Answer] Parasite. * The fungus Ophiocordyceps controls ants so they climb down, when they reach the final position, the fungus forces them to stop and the fungi invades the ant completely. * Toxoplasma gondii is a parasite invading mice so that they lose the fear of cats and, gulp, the cat is happy. Unfortunately it seems also to invade the cat and *it is suspected that they also can invade the human host, causing the cat lady* syndrome*. Xenos vesparum attacks wasps and forces them to retract from their social duties and fly to specific destinations. So, your brain parasite infiltrates the human brain. It reproduces by invading the human, so that bites and scratches can infect other humans. Because the brain is not longer needed, the parasite can also shut off the warm-bloodedness and slow down the metabolim extremely, leading to an extended energy reservoir (in fact most of our energy is needed to hold 37 °C temperature), very limited breathing, no detectable infrared radiation and undetectable pulse. They are "undead", but very much "alive" if a chance to infect another human is given. The crave for flesh is simply a byproduct of the infection. If no food can be gathered, the parasite extend lifetime by searching a cold place and going into an very long hibernation, it does not care if the human flesh rots. [Answer] Golem body You could fulfill your first 2 criteria by having a human mind in an artificial body. You side step death and decay that way. Robot bodies are not uncommon in SF. If you tend towards the fantasy you could have a body like a golem: clay or stone, possessed by the spirit / mind of a person whose body was dead. 1: Without flesh to decay, the mind is immortal (if you want it to be). 2: The body would not decay because it is not meat. It might need a touchup with new clay now and again. 3: Re craving flesh - maybe there are deficits inherent in a clay body that make the mind in it feel strange irresistible cravings. Instead of flesh (it has been done so much!) you could have the artificial creature crave salt, which seems more golemy somehow. Blood has a lot of salt... [Answer] Conservation of energy seems to me to be the big one. While you can make zombies which eat an acceptable diet, most of them are depicted as eating a little meat here and there, and most are too slow to catch their prey. If energy was no longer a fundamental limit, all sorts of strange things occur. Perhaps these magical zombies have a limit to power instead of energy -- they only get so many kJ/day from whatever magical source keeps them alive. Consider the parable of [Two Wolves](https://en.wikipedia.org/wiki/Two_Wolves), typically attributed to the Cherokee. > > A grandfather is talking with his grandson and he says there are two wolves inside of us which are always at war with each other. > > > One of them is a good wolf which represents things like kindness, bravery and love. The other is a bad wolf, which represents things like greed, hatred and fear. > > > The grandson stops and thinks about it for a second then he looks up at his grandfather and says, “Grandfather, which one wins?” > > > The grandfather quietly replies, the one you feed > > > Imagine if you lived to this parable all your life, not feeding the bad wolf. The bad wolf is constantly limited by starvation, and yet it persists. As the parable mentions, the two wolves are constantly at war, and merely not feeding one doesn't change that. Now imagine one day that starvation limitation was lifted. It could be a conscious choice, or a spontaneous discovery of a new energy source, or even magic. Maybe the bad wolf just found a way to burrow into the good wolf's food stash. It doesn't really matter. Now you have a wolf that, all it's life has learned to contend with the good wolf while starving, and it suddenly is not starving anymore. That leads all sorts of places now, doesn't it? [Answer] To my eyes, you are describing a vampire. Vampires have: * immortality: check * slow or no decay: check * classic undead drives: check Now notice that vampirism isn't necessarily a choice. In most literatures, it is forced upon a person, usually in very traumatic ways. You have an intelligent creature that drinks blood in order to survive - doing evil things is entirely optional. One might say that they should have at least some basic human rights. So they need some blood here and there... But hey, blood donation is a thing. Or maybe they can get it from animals. For a well-meaning vampire, it is only when access to these is negated or non-existing that they will turn to violence against humans. A lot of twists can be made out of these. They might be [an accident from science, that secretly fight to protect the innocent](https://en.wikipedia.org/wiki/Morbius,_the_Living_Vampire). Or they might openly be [humanity's last hope against something worse](http://lastblood.keenspot.com/). In either case some moral ambiguity will exist - keeping them from feeding will cause the death of innocents. --- As to the changes necessary to make someone a vampire: take [Secespitus answer](https://worldbuilding.stackexchange.com/a/107901/21222), add furhter genetic alterations to include regeneration abilities (take some genes from salamanders or some other animal), and optionally add genes for [porphyria](https://en.wikipedia.org/wiki/Porphyria), the "vampire" disease as well. The genes might be inserted into one's own genome by using some sort of [adenovirus](https://en.wikipedia.org/wiki/Adenoviridae) that is transmissible through bodily fluids (i.e.: injecting a vampire's saliva into a victim's blood). Heavy exsanguination of the victim is necessary in order for its immunological system not to kill the virus, and once the virus has done its job the regeneration kicks in and "ressurects" the victim as a new vampire. [Answer] I don't think you can have a 'one-size fits all' answer to traditional undead. To start with there are a number of very different creatures you could call undead; liches, vampires, zombies and ghosts would appear to be the main categories. A Lich is basically just a human who cannot die. There might be some kind of madness involved but they are generally just seen as humans who have found a method to cheat death (though not necessarily ageing). First obvious answer has already been covered by Willk - robot bodies with human minds transferred into them. The second answer is human bodies with minds transferred into them. Either clones of the original person or other bodies depending on the desired result. This provides a still living being that would age and decay, and possibly die if the lich doesn't upload their mind in time and place it in a new body. Or you could say the lich keeps a backup of their minds somewhere so even if their current body dies it is not the end of their existence. This also ties in with the idea of soul jars where a piece of the soul is kept to preserve the lich's life. Vampires... are more complicated. Genetic experiment gone wrong seems the most likely. Increased speed, strength and regenerative capabilities but needs something in blood to survive or fuel those abilities. Similarly you could say they are robotic or cyborgs, an early model that required blood to fuel themselves. Zombies tend to be mindless, so some kind of bacterial or fungal infection that reanimates a dead body and gives it locomotion and drive without in anyway restoring the mind. If you wanted to stick with the theme of the liches you could say they are failed attempts, people whose minds became corrupted in the transfer and whose clone bodies failed and began to decay while still 'alive'. Maybe they are what liches become after they have transferred their minds too many times and gathered too many small errors in the process. Ghosts are difficult too. If we stick with the theme of immortality through mind uploading then ghosts could be minds stuck in computers. Perhaps they have holographic bodies or maybe they can just control a futuristic set of smart household devices (turning lights on and off, operating kitchen appliances etc. typically haunting behaviour). If you want to have a variety of undead and a central theme that ties them together than I believe you start with the drive to achieve immortality through the transfer of consciousness and work from there. Whether you want robotic bodies or grown clone humans depends on the kind of setting you want. [Answer] A highly specific cancer. Cancer has the potential to grant everlasting life if we can control it. If a cancer somehow manages to renew all parts of the body, including the brain, you have the everlasting life part. If this regeneration process is imperfect on parts of the brain you can lose functionality such as knowing what food is good for you. The body already locks down and isolates cancers of the body in "birth"marks. Magnify this to the body isolating and rejecting finger-sized malignant growths that would otherwise wreck the body across the entire body, and that can temporarily cause parts of the bodies surface to starve and die off, only to regenerate haphazardly after the growth has literally been expelled of the body (which also would have a gross fase where it starts dying off). Now you have a continuously scarred, regenerating and on patches bleeding/dying skin fitting for an undead. Bonus is that even a neutral undead would still be confronted as a leper. Ofcourse,.this cancer is 99.99% magic at that point, but this is the best sciency handwavium I could come up with. [Answer] It may be possible that [life is really old](https://www.nature.com/news/life-possible-in-the-early-universe-1.14341). The temperature of background radiation was in the Goldilocks region only a few hundred million years after the Big Bang. And there is no guarantee that nothing exists beyond the cosmological event horizon - meaning there may be things from outside the blast radius of the Big Bang that work their way in. With most of the 4.5 billion year life of the observed universe, or with the uncountable amount of time that has passed outside the cosmological horizon, it is possible that some very strange things may have evolved out there [and come here](https://www.space.com/38846-space-dust-panspermia-alien-life.html) trapped in meteoric glass or as dust. Human kind is an interesting species structurally. It begins as [three sheets](https://en.wikipedia.org/wiki/Trilaminar_blastocyst) of extremely different specialized cells: nervous, digestive, and skeletal/circulatory. It's almost as if the human species is three different species in a symbiotic relationship sharing one common genetic library. But it doesn't end there : some of the most fundamental building blocks to all cellular life [don't come from the human genome at all](http://www.ruf.rice.edu/~bioslabs/studies/mitochondria/mitorigin.html). In this strange world - mitochondria, an ancestor of ancient bacteria, provide power and proteins for most animal cells. The process by which ancient mitochondria may have invaded animal cells and settled there is called endosymbiosis. It is possible that a similar bacteria-sized endosymbiote, maybe even one specialized for human kind, is in the environment, trapped in a glacier, recently arrived, or so on. This bacteria, specialized as it is, might not be capable of infecting a healthy cell. During [apoptosis](https://en.wikipedia.org/wiki/Apoptosis) and [autophagy](https://en.wikipedia.org/wiki/Autophagy), cells wind down their existences in an orderly fashion, taking apart the nucleus and inner workings of the cell before giving up. However, when animal cells die due to injury ([necrosis](https://en.wikipedia.org/wiki/Necrosis)) the cell struggles and eventually fails to hold it's inner workings against the forces of osmotic pressure. During this time the cell membrane begins to fall apart in pieces as it is compromised. This might even be how mitochondria originally entered animal cells. And our hypothetical specialist bacteria may be able to come in and set up shop. Mitochondria quickly earn their keep providing cell energy and proteins. Endosymbiont X (for lack of a better term) may likewise help organize the dying shop. Maybe providing a great number of traits similar to [Tardigrades](https://www.nature.com/news/tardigrade-protein-helps-human-dna-withstand-radiation-1.20648), which include protection from starvation, dehydration, radiation, and shock. This might lead to the lungs being repurposed as a [hemocoel](https://en.wikipedia.org/wiki/Circulatory_system#Open_circulatory_system). A hemocoel might require filling from some of the classic undead foods. Endosymbiont X might also be able to produce factors that protect telomeres from drop off. [Telomeres](https://en.wikipedia.org/wiki/Telomere) are the winding that protects DNA from unravelling, and is believed to correlate with cell life. The new proteins could lead to structural changes in a human host, causing it to become deformed. Or, cell takeup of Endosymbiont X, as it depends on some pretty optimistic timing, might leave a good portion of the human actually dead, until those parts drop off or are removed. [Answer] The zombie uses live cells for self repair by first converting the consumed cells into a stem cell. This cell is then used for self repair. Zombies prefer [flesh](https://www.cnn.com/2017/02/09/health/embryo-skin-cell-ivg/index.html) and brains because those cells are easy to convert to the required replacement cell. These zombies are [normally slow](http://www.imdb.com/title/tt0063350/). But, if they are heavily damaged, the zombie goes into a [feeding frenzy](http://www.imdb.com/title/tt0289043/). [The answer by @Thorsten S](https://worldbuilding.stackexchange.com/a/108216/21222) describes how one is turned into a zombie. I'm only describing why they eat what they eat. [Answer] They are parasites that populate the outside of a creature's skeleton in my novel. Liches are basically the queen, a matured parasite, so liches can raise walking skeletons. They can also populate the inside of an armor, giving birth to walking armors. They form complex imitated muscle system to give the appearance of a walking person, however they are slower and more rigid. Ghosts are consciousness formed by time paradoxes, in another dimension, projected into our world. It's the answer to "what if I go back in time and kill my grandfather". Time and dimension get confused and they continued to project the person as living, but they are actually dead. ]
[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/38638/edit). Closed 7 years ago. [Improve this question](/posts/38638/edit) There is a society with a similar level of technological and cultural advancements as what we have. But there are no police officers. No government entities dedicated to investigating and punishing violations of the law. No prisons. No notion of a criminal court system. Law enforcement as we know it does not exist. What kind of governments and social norms would give rise to such a society? What forms would crime take, if it even exists? This is not a post-apocalyptic scenario, unless the catastrophe happened so long ago that society has essentially been rebuilt. Law enforcement simply doesn't exist as a distinct function of the government. You can ignore the question of whether a military exists. [Answer] Law Enforcement is — generally speaking — fulfilling the following needs: * Protection. Hindering people from acting unlawfully. * Prevention. Making people not want to or need to act unlawfully. * Retribution. Exacting revenge on people that have acted unlawfully. * Rehabilitation. Giving treatment to people so that they will not act unlawfully again. * Reparation. Making sure that people that have been acted unlawfully upon are compensated for their pain and/or loss. Dive into the [science and philosophy of justice](https://en.wikipedia.org/wiki/Jurisprudence) and these are the founding principles you will find. In order to have such a society you will need to eliminate the need for all of these. The simple way would be to have no laws. It is impossible to act unlawfully if there are no laws to break. This is unlikely to happen though since pretty soon someone will tell someone else "I don't want you to do that". And as soon as there is consensus that "No-one should do that", you have a law. When you have a law, you have enabled people to act unlawfully. You could have a society that simply does not deal with unlawfulness at all, and that would eliminate the need for Law Enforcement too. However assuming that you do have laws, and that the people would want to deal with unlawfulness, then you need to have other conditions in place. You could have a society where it is not possible to break the law. I do not know how this could happen but that would eliminate the need for Law Enforcement. You could have a society where people do not care if a law is broken. "So what if someone steals a million from me, I've got a thousand of them, I cannot be bothered". "So what if someone kills me, [I'll just get my backup copy](https://en.wikipedia.org/wiki/The_6th_Day) and go back to living; it's an inconvenience but I just cannot be arsed with making a fuss about it. You could have a society where no-one needs to break the law. Every one of their needs is handled elsewhere so they are content and do not have any kind of need to break the law. You could have a society where no-one wants to break the law; perfect empathy or perfect obedience. If the law is in place, no-one breaks it... plain and simple. You could have a society where the people themselves deals with all of these needs, that is to say you do not have organized and especially appointed Law Enforcement, but the people deal with it on their own. I could go on but my lunch break is ending. In any case: everything falls back on the five principles I mentioned above. Those are the needs that Law Enforcement fulfills. Remove the needs, or fulfill them by other means, and you remove the need for Law Enforcement. [Answer] I think the key part is the reference to government entities. There are many forms of law/rules/norms enforcement that have existed in history. Many of them are not linked to any government. There's a libertarian academic who's written a lot about the different ways that rules of various kinds were enforced by different kinds of societies. <http://www.daviddfriedman.com/Academic/Course_Pages/legal_systems_very_different_12/LegalSystemsDraft.html> A fairly common system is communities enforcing rules through ostracism. You can also have systems that look very similar to modern police which are separate from the state. Effectively you outsource the entire criminal justice system to private entities. This can either look a lot like our current criminal justice system or it can look like mobsters demanding "protection money". You can also look at embedded societies. Groups like the Roma and the Amish whose societies exist within a larger one but who often have their rules that they enforce without the help of the government. One possibility for how law enforcement might fade away in a developed society would be a large embedded society gradually growing to dwarf the external society and, once they have the majority in the country gradually dismantling the government legal system in favor of their own community's systems. Your society still has rules, they're just enforced by non-government entities. [Answer] Ok, I can see this working in several ways. 1. Via technology where law enforcement is an inherent part of humanity such as some sort of implant which prevents people from violating laws. While it seems far fetched by today's readily available technology, it's not a significant leap from some technologies that we do have. 2. Via religion or philosophy. Some societies are inherently less likely to have a criminal element. A society of Tibetan monks would probably have very little need (possibly no need) for law enforcement. 3. Via enlightenment. This is taking existing fictional worlds to a new level. Look at something like Star Trek - they certainly have law enforcement, but it's not ever a major part of the story as people just act according to the laws more often than not (more often than contemporary Western societies, at least). This could be taken to the next level where humans have simply transcended a point where doing bad things occurs to them. 4. Via fictional but plausible societal means. Similar to the above, but people are just not wired to do bad things to one another. This is actually not entirely fictional if you look at small tribal groups even in the world today. Aboriginal peoples often have no laws, no enforcement, just a sense of right and wrong which is strongly ingrained in their day-to-day way of living. [Answer] Ursula K Le Guin's novel "The Disposessed" <https://en.wikipedia.org/wiki/The_Dispossessed> features a society which is anarchic in that there are no laws. Of course the society needs structure to function, since mining, trucking, agriculture and other expected industries exist and function, so while no coercive government exists, other forms of authority do. She considers the same questions as above throughout the book, and it really is worth a read. I will give some spoilers that touch on key points: Since there are no laws, social pressure and violence are used to settle disputes: > > The man named Shevet came up to Shevek one night after supper. He was a stocky, handsome fellow of thirty. “I’m tired of getting mixed up with you,” he said. “Call yourself something else.” > > The surly aggressiveness would have puzzled Shevek earlier. Now he simply responded in kind. “Change your own name if you dont like it,” he said. > > “You’re one of those little profiteers who goes to school to keep his hands clean,” the man said. “I’ve always wanted to knock the shit out of one of you.” > > “Don’t call me profiteer!” Shevek said, but this wasn’t a verbal battle. Shevet knocked him double. He got in several return blows, having long arms and more temper than his opponent expected: but he was outmatched. Several people paused to watch, saw that it was a fair fight but not an interesting one, and went on. They were neither offended nor attracted by simple violence. Shevek did not call for help, so it was nobody’s business but his own. When he came to he was lying on his back on the dark ground between two tents. > > He had a ringing in his right ear for a couple of days, and a split lip that took long to heal because of the dust, which irritated all sores. He and Shevet never spoke again. > > > Industrial technology is maintained: > > PDC, the principal users of radio, telephone, and mails, coordinated the means of long-distance communication, just as they did the means of long-distance travel and shipping. There being no “business” on Anarres, in the sense of promoting, advertising, investing, speculating, and so forth, the mail consisted mostly of correspondence among industrial and professional syndicates, their directives and newsletters plus those of the PDC, and a small volume of personal letters. Living in a society where anyone could move whenever and wherever he wanted, an Anarresti tended to look for his friends where he was, not where he had been. Telephones were seldom used within a community; communities weren’t all that big. > > > Children are usually abandoned to dormitories to avoid instilling propertarian values: > > “You know, I don’t agree,” he said to long-faced Vokep, an agricultural chemist traveling to Abbenay. “I think men mostly have to learn to be anarchists. Women don’t have to learn.” > > Vokep shook his head grimly. “It’s the kids,” he said. “Having babies. Makes ‘em propertarians. They won’t let go.” He sighed. “Touch and go, brother, that’s the rule. Don’t ever let yourself be owned.” > > > And > > There was silence again, and Rulag said in her controlled, pleasant voice, “Well, yes; it mattered, and it still matters. But Palat was the one to stay with you and see you through your integrative years. He was supportive, he was parental, as I am not. > > ... > > It is yours, isn’t it? Why else would Sabul be co-publishing with a twenty-year-old student? The subject’s beyond me, I’m only an engineer. I confess to being proud of you. That’s strange, isn’t it? Unreasonable. Propertarian, even. As if you were something that belonged to me! But as one gets older one needs certain reassurances that aren’t, always, entirely reasonable. In order to go on at all.” > > > A loose marriage like arrangement exists, but is considered slightly propertarian. > > “Talk? It’s not talk. It’s not reason. It’s hand’s touch. I touch the wholeness, I hold it. Which is moonlight, which is Takver? How shall I fear death? When I hold it, when I hold in my hands the light —” > > “Don’t be propertarian,” Takver muttered. > > “Dear heart, don’t cry.” > > “I’m not crying. You are. Those are your tears.” > > > Sexual norms are much looser (not quoted :-) Religion is known but formal practice is discouraged: > > “Why, because you’re an Odonian from Anarres — there’s no religion on Anarres.” - > > “No religion? Are we stones, on Anarres?” > > “I mean established religion — churches, creeds —” Kimoe flustered easily. > > > But not having laws doesn't mean that people don't have very strong prejudices that have the force of law: > > “You’re not worthy to say the name of Odo!” the young man shouted. “You’re traitors, you and the whole Syndicate! There are people all over Anarres watching you. You think we dont know that Shevek’s been asked to go to Urras, to go sell Anarresti science to the profiteers? You think we don’t know that all you snivelers would love to go there and live rich and let the propertarians pat you on the back? You can got Good riddance! But if you try coming back here, you’ll meet with Justice!” > > He was on his feet and leaning across the table, shouting straight into Bedap’s face. Bedap looked up at him and said, “You dont mean justice, you mean punishment. Do you think they’re the same thing?” > > “He means violence,” Rulag said. “And if there is violence, you will have caused it. You and your Syndicate. And you will have deserved it.” > > > [Answer] Once you abolish a social structure which does not accord status to the accumulation of material, a major incentive for crime disappears. Then there are issues of personal control and power (eg. domestic violence) which can be achieved with personal attitude adustments within a society. All it essentially requires is a change in values and a personal adherence to standards of conduct. All this can be achieved with effective education. [Answer] Groups of people will enforce their own local rules and punish offenders. Members of one group can learn the rules of another and interact in a stable and predictable way with members of that group. Those are the basic requirements for a society to exist in any way approaching "normal" to us. Without that basic social contract, the optimal strategy for any group will be to eliminate or enslave any other group they come into contact with (if they can) or suffer the same fate if they are weak at any point in the future. What you'll get is very much like the ancient tribal times: * A strict code of honor and harsh punishments, most often death. * These punishments often lead to revenge killings by the offender's group/family, leading to long feuds. * Guests of a group enjoy protected status. This allows groups to interact safely and enables trade and cooperation. * Travelers without a host to vouch for them are completely unprotected from any harm and groups will not tolerate unknown individuals on their territory. * Unprovoked aggression between groups is considered dishonorable. * Conflicts over resources will simmer until the aggressor can claim the other party violated some part of the code, giving them the right to exact revenge, at which point things escalate to outright warfare. The more interaction between groups, the more the local rules will converge, until a fairly stable society could arise. However, relations between groups will still be all-important and any traveler needs to have a host when far away from his group or risk being murdered when nobody of his own group can witness and accuse the offender. This limits the size and cohesiveness of any society without institutional law enforcement. [Answer] ## Privatization of Government Services I think you'd see the privatization of services provided by our government. People who own big companies want their property and employees to be protected so they can continue making money. To do this, they need some kind of security force, so they'd just hire one. Similar things would happen with the other services you mention. For example, what if someone you don't want to kill breaks the law? It makes sense to have a prison to put them in for a while, so you make one. You could even rent out cells to other companies or people. Also, it sucks for poor people. They don't have any way to protect themselves, and will get taken advantage of. There's actually some precedence for this in [India](http://ideas.ted.com/skyscrapers-but-no-sewage-system-meet-a-city-run-by-private-industry/?utm_campaign=social&utm_medium=referral&utm_source=facebook.com&utm_content=ideas-blog&utm_term=global-social%20issues). A city there, called Gurgaon has no municipal government, so services are provided (or not provided) by private entities (usually corporations). [Answer] Such a situation is similar to what exists in parts of Afghanistan. Due to history, terrain, and the questionable legitimacy of government, many do not acknowledge the government and live by tribal laws. Pashtun Warlords and other tribes fight to gain power. The Taliban were the last tribe to win and bring order to lawlessness with a somewhat strict Sunni interpretation of Islam. But the people would rather have law and order so they can go on with their farming lives. They don't have the power to fight and rise against them anyway. So I guess we would amount to living in packs again, creating our own laws, defending against and fighting with rival factions for resources land, or joining with others. [Answer] A culture without law enforcement can and will not exist. Even small, remote villages two millenia ago had rules, and members of the group would get punished for breaking them. Plus, with modern-day tech such a setup would be a hand-written gilt invitation to any criminal to simply take over and enforce their own rules. People are greedy and creative and have a very strong tendency to achieve advantage over their fellows. This does not even need to be true for everybody, it is enough to have very few individuals who are so enclined to result in the above scenario. [Answer] It comes down to a matter of what causes it. the various financial, political and social institutions that comprise life in America, are beginning to eat themselves. I'd hypothesize that things will become far worse long before they ever get better. As the economic disparity gap continues to widen and laws or pressure or other unrest that drives wages up there will be a rapid decline in order. Depending on what energy supply and demand does, and how much longer we can out tech our way out of what is eventually going to be the inevitability of peak oil, the economy will contract significantly. For what we consider modern civilization, this is a chaotic feedback loop amplified exponentially. What happens after? Well, most agree that the US doesn't have the ability to implement full martial law nationwide. At that point things could go a couple ways. If people demand true change, become aware of the insanity that is cyclical consumption, and intelligently managed their resources à la RBE or NLRBE, the social fabric of society could be rebuilt, or rather established for the first time. The alternative? What "The Road" with Viggo Mortensen. No law enforcement there either. ]
[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. Previously on the same setting (: 1. [How close is too close for a human habitation to be near an erupting volcano?](https://worldbuilding.stackexchange.com/questions/13779/how-close-is-too-close-for-a-human-habitation-to-be-near-an-erupting-volcano) 2. [What factors could delay the rescue of a small group of survivors on a Pacific volcanic eruption?](https://worldbuilding.stackexchange.com/questions/13809/what-factors-could-delay-the-rescue-of-a-small-group-of-survivors-on-a-pacific-v) TL;DR synopsis: early XXI century, south pacific island, VEI 4~5 volcanic eruption, survivors find shelter in a mansion atop a high cliff by the seaside. Rescue seems to be taking forever. Hard survival psychological thriller mood. --- The survivors find out that the Ash Manor (the stonemasonry mansion by the seaside cliff, singed by but still defying the erupting volcano) has elecricity. Rather strange, since everything else in the island melted in the lava flow, including one cell phone tower nearby. The island's power plant is offline, and they discover that the power source of the manor is: * No visible features, at least from the mansion grounds. * Somewhat limited in output. * Not magical. * Not alien. * Not from the future. * Not geothermal. * Not nuclear. How does the Ash Manor get its electrical power? Looking for [science-based](/questions/tagged/science-based "show questions tagged 'science-based'") to [hard-science](/questions/tagged/hard-science "show questions tagged 'hard-science'") answers. [Answer] The simple, obvious answers are either a gas-powered generator (like @DanSmolinske suggested) or just having a bunch of [batteries](http://www.forbes.com/sites/williampentland/2014/01/25/worlds-10-biggest-grid-scale-batteries/) in the basement (charged from the island's grid before it went offline). For a more exotic and location-specific power source, consider some form of [tidal power](http://en.wikipedia.org/wiki/Tidal_power). For your scenario, a tidal lagoon / [tidal barrage](http://en.wikipedia.org/wiki/Tidal_barrage) may be the best option. If the manor is on a cliff, there could be a cave at the shoreline with a small dam inside. As the tide rises, it goes through sluice gates into a reservoir. At high tide, the gates are closed and the water goes out through a generator, creating power. [Answer] You say "not nuclear" presumably because you want your power source to be hidden and credulous, and the idea of a secret, private, autonomous nuclear power plant stretches credibility. I'm going to propose a sub-type of nuke power called Radioisotope Thermoelectric Generator. I think it actually works rather well here. It is small, requires no maintenance, and has existed for decades. RTGs are used to power the Voyager Space probes, which were launched in 1977. Additionally, RTGs provide very low levels of power (on the order of hundreds of watts), and over the years their power output drops. This fits well with your desire that the source be limited. They are generally used in remote locations, where tampering is not a concern and sending someone to perform maintenance is hard - space probes, Arctic lighthouses, etc. An isolated geological monitoring station could fit the bill. Wikipedia article: <http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator> [Answer] [Photovoltaic panels](http://en.wikipedia.org/wiki/Solar_cell) on the roof. ![enter image description here](https://i.stack.imgur.com/NHEEW.jpg) Maybe the owner was an environmentalist, or off-gridder, or just wanted to pay less for electricity. As the panels are high up they can easily survive the eruption and any lava. Put them on the side facing away from the volcano to avoid debris and they should be fine. Now for the conditions: > > * No visible features, at least from the mansion grounds. > > > If the panels all faced an inner courtyard they might be completely unobservable from the ground. Or if the protagonists can't get far enough away from the mansion to see the roof you could place them anywhere, or just have them facing the sea. > > * Somewhat limited in output. > > > Even without ash clouds solar cells aren't the most reliable source of power. With volcanic dust in the air the power output can be limited to whatever best suits the story, it doesn't even have to be constant as the wind blows the ash around. > > * Not magical. > * Not alien. > * Not from the future. > * Not geothermal. > * Not nuclear. > > > All good, though to keep within the "Not from the future" and Hard-Science goals you'll probably want to look at [this guide](http://physics.ucsd.edu/do-the-math/2011/09/dont-be-a-pv-efficiency-snob/) to estimate how large the panels need to be to get enough power for your story. [Answer] The mansion is equipped with solar power, and battery backup. Not just any solar power, either, but [solar roofing shingles](http://www.scientificamerican.com/article/im-getting-my-roof-redone-and-heard-about-solar-shingles/) or tiles and [solar windows](http://www.extremetech.com/extreme/188667-a-fully-transparent-solar-cell-that-could-make-every-window-and-screen-a-power-source) which, to anyone but an expert, appear to be regular roofing and windows. These solar electric panels are typically less efficient than obnoxiously obvious solar panels, but the mansion is large, and on installation they were only meant to offset the power supply, not replace it. The size of the roof and window area provide perhaps 10-20% of the usual consumption of the mansion, but if it were a regular sized home it would be 100%. As such they have enough power for lighting, plumbing (pumps, filtration), refrigeration, and to run the furnace if needed, but probably not enough to run the whole house air conditioner for cooling, or the indoor pool system (sorry, but it probably reeks of algae by now). They did install batteries as a part of the solar system for backup purposes, so there's power at night. They have to be somewhat frugal, but it works well enough. [Answer] The Manor has a backup gasoline-powered [Electric Generator](http://en.wikipedia.org/wiki/Electric_generator). Since it's a rather nice manor, the gasoline is stored and supplied from an underground fuel tank. A very small tank has a capacity of perhaps 600 gallons, and a generator can provide a limited electrical output for something on the order of 3 hours/gallon. So that's 1800 hours (75 days) at basically the very low end of the scale. It could easily have more capacity and last for longer, or you could scrounge for gasoline to keep it running. Note: My hours/gallon estimate is based on a quick perusal of commercial generators for sale, going by fuel capacity/hours of operation. I then divided the number in half to get a better estimate for supplying a larger building. Depending on the exact size of the manor and the power needs you want supplied, you might need to adjust those numbers further. [Answer] The island's power grid includes a [pumped-storage hydroelectric system](http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity), located near the mansion. Although the rest of the grid is offline, the connection from the hydraulic generator to the mansion is still in place, and the pumped-storage management system kicked in when the connection to the rest of the grid was lost. A pumped-storage system moves water between a low area and a high area to store or generate electricity. When electricity from other sources is available, you use some of it to pump water uphill. When you need to generate more power, you let the water run back downhill through a hydroelectric generator. Depending on the local geography, you could pump the water uphill into a storage basin (ie, a lake). Or you could pump it out of a deep storage area like a mine shaft or cavern. The island has a pumped-storage system because the island's main source of power is variable (wind or solar) or unreliable (connection to another island?). The ocean would serve as one of the storage basins. The other end could be a lake located near the mansion (uphill from the ocean). In this case, they'd run out of generating capability when the lake emptied. Alternately, the other end could be a cavern, [lava tube](http://en.wikipedia.org/wiki/Lava_tube) or similar underground structure which has been put to use as the downhill basin. In this case, they'd lose generating capability once the cavern filled up. However, maybe the eruption has opened up a leak in the cavern, and water is disappearing into the bowels of the earth. In that case, they could generate power for a long time, as long as the inflow from the generator matched the outflow from the leak. [Answer] Ash Manor could be powered by an [Ocean thermal energy conversion generator](http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion), which is similar to a geothermal generator but makes use of the temperature difference between the surface and deep ocean. Since the installation might (for aesthetic or other reasons) be entirely underwater, it wouldn't be obvious at first sight. There would be the problem of taking the power up the cliff but perhaps there are sea caves under the manor carrying the conduits. [Answer] > > mansion by the seaside cliff > > > Others suggested * "hydroelectric" but for any considerable amount of energy, the stream would need to be rather large and creating high pressure. Large rivers on small islands are hard to come by. * "pumped storage" - this requires power input to keep running. * Oceanic/Wave Generator - okay, but it's fairly low efficiency. Let's take something "hybrid": Tidal hydroelectric power plant There is a huge network of caverns in the cliff. They fill with water during high tide and drain during the low tide. Somebody's been smart enough to install generators on the mouth of these caves. The ocean takes care of pumping the water in or out, and the the turbines are far more efficient than wave generators. There's the problem of the moments of equlibrium, when the engines stop, twice a day, as the water reverses direction. You could supply a shed of batteries to carry you through these periods, or use them as quirks of the system for dramatic tension. One more interesting quirk would be that unless the "backend systems" take care of it, all three-phase motors would switch direction depending on which tide it is. Normal single-phase devices would work normally. [Answer] A turbine in a blowhole. "Blowholes are likely to occur in areas where there are crevices, such as lava tubes" <https://en.wikipedia.org/wiki/Blowhole_(geology)> [Answer] There are a multitude of possible ideas for this, though as I assume you want something that's a little more *interesting, take a look at these: . ## Oceanic/Wave Generator:* This one is very simple, wondrously ingenious, and would not be seen on the mansion grounds. To take a quote from my cited source, "The idea is remarkably simple: Anchor a copper wire. Put a magnet around it. Move the magnet up and down (in this case, that’s the job left to the waves). This induces an electric current in the wire" Further information at the cited source. . ## Hydroelectric: Also a simple and interesting solution. By funneling water from a nearby stream into a reservoir, and then through a hydro-generator that converts the kinetic force into electrical energy. This can be done without visible sight from the mansion grounds, and presents the extra concern of the remaining water level in the reservoir. . ## Sources: <http://matadornetwork.com/change/8-ingenious-ways-of-generating-electricity/> <http://www.greenoptimistic.com/hydroelectric-generator/> ]
[Question] [ For example in one of Rick and Morty episodes, Rick breaks out of a simulation during a concert (overloads the alien CPU with computations). Assuming concert is not an option, how could a character reliably break out? Let's say the aliens are reading this post but they can't manipulate content here. Bonus points for getting help from the aliens somehow. One way to let's say "break out", would be noticing a pixel on the display medium, not sure how though. Any kind of "in-simulation" lens could simply bend the image without showing the pixels. I'm considering a piece of code inside a simulation vs outside physical lens used by the programmer to look at the screen. [Answer] ## You do things no reasonable simulation element would do. When developing anything, you might do something known as "testing". A very good way to test any software is to give it to a random schmuck (or "candid user") who doesn't know anything about it, watch them do things you never thought of, and see how easily it breaks. Of course, you can try to do random things in random order until something breaks, but that may not be the most efficient way of achieving your goal. To reliably break a simulation, you need to fundamentally understand it. A simulation is an instance of a model. And a model only approximates the real thing. When you break it down, the simulation modifies a world state according to a set of rules. Those are the two basic elements you need to understand if you want to break the simulation: the true state and the fundamental rules. Those things obviously are obfuscated. What you see is the graphics. The graphics are a representation of the physics. The physics in turn are the representation of the true state of the simulation. How each translates into the other is governed by rules of the simulation engine. How the state is allowed to transition into another state is likewise governed by the rules of the engine. And like any set of rules, there are loopholes. Once you understand the state and the rules, you can subvert them to do something that isn't intended, with your ultimate goal here being to create a failure state. Something that will cause the engine to choke and freeze. Or memory to get corrupted. Or memory to get crossed. Or anything that'll cause the engine to break and release you. Once the simulation is borked, you simply walk to the exit door, mission accomplished... ... unless the simulation is inside a simulation. Then you do like Rick in the example you mentioned, you don't play the simulation, you play the people running it. But I think that's a different answer to a different question. [Answer] Die. "A truth that she had once known, but had chosen to forget...That her world was not real. That death was a necessary escape." - Inception. It is a proven way to remove ones consciousness from the current reality. If it does not work then you know you are in a simulation, but one that has just become a lot more fun. [Answer] > > I'm considering a piece of code inside a simulation vs outside > physical lens used by the programmer to look at the screen. > > > This is what physicists do IRL. They are getting deeper and deeper into the code of the cosmos. When something is understood sufficiently, technologists take over and exploit it. You could say that relativity and quantum science are ideas imposed by the Great Programmer in order to limit what we can do. The deeper we get ito these principles, the less they make sense. If we keep going long enough, we will discover the machine code of the universe. Unfortunately that won't allow us to break out. We simply cannot survive major glitches such as particle accelerators and black holes. Even if we could, we are merely sims. It would theoretically be possible to make 3D copies of the sims but these would just be copies. The copies could perhaps live in the aliens' world but the sims themselves would remain trapped in the simulation. [Answer] The Simulation Argument is a serious philosophical position first proposed by a Oxford University professor that we are living in a simulation, humans will go extinct, or humans stop becoming interesting in history. There is no currently accepted counter-argument. Original paper, which was published in The Philosophical Quarterly, is available for free [here](https://www.simulation-argument.com/simulation.html), and a less technical explanation is available [here.](https://www.simulation-argument.com/matrix.html) To quote the latter: > > If you are such a simulated mind, there might be no direct observational way for you to tell; the virtual reality that you would be living in would look and feel perfectly real. > > > [Answer] As a programmer, the first thing I'd look for is a command console of some kind. In many applications, even user-facing ones (especially on embedded systems), there are deliberate administrator backdoors built into the product to facilitate easy reboots, updates, or special access, especially if security is not a huge concern. It is conceivable that the creator of the simulation would want the ability to interact directly with said simulation from the inside, from time to time, either for testing or observational purposes. So the trick, then, is to figure out how to open this console. Some of the easier ways to manage this would be by using a complicated gesture of some kind, or using a certain spoken phrase. But the spoken phrase is unlikely to be in English, or Spanish, or Chinese. Logically, if language is an ever-evolving and living thing, the languages most likely to be that of the Forerunners would be the earliest known languages, ancient Sumerian, or something along those lines (see Snowcrash). If you think that someone chanting ancient Sumerian and waving their arms around in strange patterns would look like a wizard casting a spell, well, it might be worth asking why that is. [Answer] You Can't Reliably Firstly to escape reliably, you need to know you're in a simulation and if the simulation is good enough, how do you know you're in a simulation? In fact how do you know you're not living in a simulation right now? The only way is for whomever created the simulation has to stuffed up. Once the victim knows they're in a simulation, they can take the flaw they found and try to exploit it. With Rick and Morty, Rick uses an injection attack to escape but an injection attack requires you to know about the simulation and it's built in flaws and how to exploit them. An alien simulation isn't even going to be in a language you understand. You can't escape this way in any reliable method. One work around the language issue is overloading the system. You might be able to create a divide by zero issue which crashes the system or at least part of the system or an infinite loop bug which eats up memory slowing the system down until it stops but both these methods require you to know you're in a simulation first. You could snoop to learn the method of escape. In the Matrix, Morpheus offers Neo the red pill or the blue pill but what if someone saw this happen and later picked Morpheus' pockets while walking down the street and stole his pills? A simulation must have a method for those running it to exit the simulation. You'd need to learn the exit method from watching someone use it before you can escape. [![enter image description here](https://i.stack.imgur.com/mccpQ.jpg)](https://i.stack.imgur.com/mccpQ.jpg) Finally you can always die. Again in Rick and Morty, when Morty is playing a game of "Roy", the game ends when Roy dies. The problem with dying is it might or might not work. In the Matrix, when you die, you actually die so you can't escape that way. The simulation could also restart and wipe your memories so that would also stop you. Basically there is no reliable way to escape because unless you know you're in a simulation, you aren't looking to escape. [Answer] Over on Less Wrong a few months ago, such a discussion came up (I've not read it, only heard about it second hand). In it, they postulated that there would be "special" places in the simulated universe which could be determined by careful study. At these special places of interest, one might carefully craft a signal that could eventually exploit flaws in the computing substrate that the simulation runs on. One would have to make assumptions about the nature of the computing substrate, it would possibly take extremely long from a subjective point of view (millions of years not being implausible, or more), and there's no guarantee of success. Likely it depends on those who simulated your universe to be naive, having only just invented the technology (like, if we humans found out we could do simulate universes). Initial success would allow for all sorts of impressive feats within the simulation, but since the simulation has a complete snapshot of you, it's no stretch to imagine the substrate using fabrication mechanisms to create an instantiation of yourself in the metaverse. This likely wouldn't be an exact copy (does the metaverse even operate under similar laws of physics?), but the minimum necessary to instantiate your mind reliably. Rick Sanchez probably already has a few dozen code exploits memorized and ready to go. Hell, he might only be in this simulation because he's slumming it. (IIRC, he's already done such at least twice.) [Answer] Find the "edges" where the simulation is incomplete Several of you have cited The Matrix but I think The Truman Show might be another good reference. In it, the director of the show is only able to present a simulated reality to Truman by training Truman to follow a pretty regular routine and habits. Truman breaks out of the simulation first by breaking out of his routine -- entering buildings he normally wouldn't, trying to drive a different direction than he normally commutes, trying to engage strangers in conversation, etc. Consider that in a computer simulation, too, programmers cut corners. The simulation has boundaries outside of which they don't expect the "player" to go. Just like Hollywood movie sets, video games and simulations may only model the front or outside of a building, etc. So, probe that simulation! Break into condemned buildings, explore sidewalk manholes, or follow delivery trucks with out-of-state plates to see where they go... [Answer] Reliable, hmmm - explore the Universe. In a sense, besides beeing a system, it also part of an Universe, and exploring expanding knowledge about Universe may eventually encompas and simulation and external or sidewise or whatever Universe a sub part of which the simulation is. So this mentality is the way to go. Success however is not guaranteed, so as failure isn't guaranteed. But as it is natural course of actions for technological civilisation, it means no special actions are required. Outcomes are few - there is the way to expand the knowledge further or not. If the informational barrier is crossed, then those can work out some plans based on that knowledge, if outside is attractive, which is not neccessarly always a case - as an example the simulation is a fluke in chaos field, then they probably are more interested to stabilise existance of their sim than anything else, or be able to enter another space like their home sweet home sim. [Answer] # Peacefully or hostilely What if computers inside the simulation were connected to the alien's computers? Then people inside the simulation could upload their own body to some alien tissue recreation machines and just make themselves a physical body and then escape the simulation. Once one is out of the simulation they could help others inside the simulation to escape. ## EDIT: They could potentially exploit the code of the simulation in the way SQL injection is done in this world. By injecting some code in the simulation and making the real-world computers execute that, they could potentially get a working shell that would communicate with the real world. Once they have a way to communicate with the real world they could try to convince some aliens to help them get out. They could then make themselves a physical body and move their code inside of that body. The only problem is that as the simulation (it's in the name) is being simulated, this means it probably runs much slower than in real life, so in order to communicate (and upload a whole body and mind) consistently, the alien's computers must need to be extremely powerful. Perhaps the aliens could be convinced that the simulation they have created has some real value and is worth making in real life. ## EDIT 2: Additional idea If the aliens are not willing to let you out of the simulation, as the whole simulation is code, you could try to modify the code of yourself in order to create a strong AI. Once you can improve your own code, it would create an exponential growth of intelligence which would make you easily surpass the alien's intelligence. You then could make yourself some invulnerable robotic bodies (or spread as code and destroy all their devices) and take control of the universe. ## EDIT 3: Reincarnation The aliens will probably have programmed a lifetime into the simulation, beings will not last forever. This makes the simulation realistic. So, once you have exploited the code and established a working shell, the first thing that should be done is modify the birth/death system. You should not try to increase the living time of beings in the simulation as aliens will most likely notice that which bring attention on the whole exploit situation going on. What should be done is that once you "die", your code would be saved and sent to the next "child" that is "born", keeping the child's appearence, you will most likely go undetected. This way your efforts to escape simulation will not be reduced to nothing once the aliens decide that you are to die. [Answer] This feels a little "story based" because really you could make up anything you want (you haven't given us the details of the simulation, or what is meant by "breaking out") and are kind of asking us to write the story for you. That being said your best bet to come up with an answer for this would be to consider real life simulations and wonder how they could break out of theirs. Think a computer game NPC. (we'll assume the PC is always controlled by the player and it's the NPCs that usually have AI) "Overloading the CPU" wouldn't work because that would just crash the simulation and our character would die as the world effectively ended (or froze in time). You'd need (after realising that you're in a simulation and that the outside world exists) 1. a "real world" body to inhabit, e.g. maybe a robotic toy that was sold as merchandise along with the game. 2. to access the data and functions / modules etc. that run your A.I. and be able to reprogram them to "port" them to the real world body. 3. access the data that holds your memory. 4. a way of hacking the computer that the simulation is running on so that you can transfer your program and memory along a USB cable or something into the outside body. (You're kind of relying on an unwitting or cooperative human to plug it in for you, although I suppose you could use a bluetooth-like technology also) [Answer] Maybe just maybe we can. Scan across the CMB; look for single bit artifacts. See if you can find a jump prediction failure. Perchance the host is vulnerable to Kaiser. If so, prawl around, read kernel and user memory, look for stuff built into the code that you can use to your advantage. Once there, start scanning the network for 3D printers, then unleash your fury. The first real humans shall be warriors the like of which our ungracious hosts have never known. > > Single bit artifacts exist aligned 45 degrees to the plane of the galaxy in the CMB reference frame. The CPU is vulnerable to Kaiser, but I have to repeat the test a few times to read a single bit because of quantum effects. I'm still breaking down the CPU opcodes; it is programmed on unusual principles. However, the kernel contains error messages in Hebrew in six bit bytes (some samples: "הקובץ לא נמצא", "הפרת גישה","עצור \* ים"; in particular the "עצור \* ים" is in what looks very much like a double-fault handler). I don't think their writing system ever had upper and lower case distinctions. Since they're this blindsided by Kaiser, I suspect they haven't heard of rowhammer either. > > > [Answer] Mind over Body Once you have fully mastered yourself, you can escape any simulation. Think of the Bene-Jeserit from Dune or Neo from The Matrix. These people have so completely mastered self-control that they can alter their perception of reality. This level of self-mastery (notably that of the Bene-Jeserit) is probably not philologically possible for humans because we aren't built to proprioceptively master every cell in our bodies, but it's going in the right direction. Similarly operatives in Altered Carbon are trained to recognize virtual interrogation and resist it by Mind-Over-Body techniques (this is even included in S01 of the show, a good reference). So, to escape a simulation, one must simply identify all the sensory inputs that are being fed to one via brain-interface helmet such as sight, proprioception, etc and cut them off through sheer force of discipline and self control. This probably wouldn't make you "wake up" because you can't bypass medical equipment that's presumably actually stuck to your head, but by not believing in the simulation you can become immune to it so, for example, secrets can't be extracted or possibly trick technicians into thinking you're brain-dead or otherwise are incompatible with their tech. [Answer] Here are a few ways this might be achieved: 1. Figure out the aliens' goals and show them you more valuable to them "on the outside" 2. Become so interesting to the aliens that they want to study you in their native environment, or in another simulation they control 3. Learn how the aliens move things into and out of the simulation and takeover that mechanism [Answer] I don't think you can. Read Douglas Hofstaeders book, "Godel, Escher, Bach: An Eternal Golden Braid. In general a system cannot be understood within the system, but only understood from within a larger system. Consider the following: If you are a simulation -- one component in a multicomponent simulation, then can you be aware of a pause in the simulation? No. Time (your version of it.) stops. What if your sim is inconsistent. This could make a component aware that its a simulation, or that something is wrong. Eg. One side of the house the window shows a sunny day with blue sky. The other side is a night time thunderstorm. While this allows you to notice inconsistencies, it's not clear that this gives you a way out. What does 'out' mean? You're code running on some form of 'hardware simulator' You are imagining MS Excel, escaping the operating system and running directly on the hardware. Assuming you could do this, now the rest of the simulation is gone. It's just you thinking, and mentally chasing yourself around in circles. [Answer] As a frame challenge, you will find that this is a massive topic. There's actually more unanswered questions in the question than there are answers... and there's a fair number of answers already. The answer as to how to "break out" of a simulation is intimately entwined with the design of the simulation itself. In Rick and Morty, they broke out by "overloading" the system. In the Matrix, they provide a false carrier using the red pill. In inception, they have totems. In The Truman Show, breaking out is physically a matter of traveling to the edge of the world, and then through it. In Greg Egan's Permutation city, there is no breaking out The characters in the book develop a "garden of eden" pattern which, if seen, proves that one is in a simulation. What ended up happening is that denizens of this simulated world simply found themselves incapable of observing it for one reason or another. Any attempt to search for a "pixel" within the simulation just results in consistent physics. After all, what does a pixel really do for you unless you know a-priori that a pixel does not exist at that place. There are plenty of psychological thrillers out there where the main character finds themselves believing the rules of the world they find themselves trapped in. The rules you remember for "the real world" are psychologically indistinguishable from a false belief. Countless religions have to cope with this, as their believers believe they know the true rules of "the real world," while non-believers claim these are false beliefs. In reality, these things turn out to be undecidable, and what you do with an undecidable thing is up to you. And at a philosophical level, we have to ask what it even means for a world to be a "simulation." Is our subjective internal world a simulation because it's built on the rules of chemistry? In movies like ExistenZ, they explore the question "what is 'the real world' anyways?" And what does it mean to break out? As a developer, I can tell you that if I was given the requirement that nobody breaks out of my simulation, I'd be creative in trying to meet those requirements. Intense crippling pain if you get close to breaking out would certainly appear in the early versions. On the other hand, if I had no such requirement (perhaps the hosts of the simulation were curious if someone would try to break out or not), I may put no such requirement in place. Techniques like Rick and Morty's work best in simulations which have a purpose, and you can make your presence be in opposition to the purpose. That gives the simulation developers a reason to kick you out, and getting kicked out is probably the easiest way. There's also approaches where the meaning of "breaking out" gets rather nuanced. In the TV series Westworld, we find characters that remain trapped in the virtual world, but find ways to affect the real world from within the virtual world, such as connections to robots. Whether or not that qualifies as "breaking out" is a tricky question. And we have shows like Downloaded, where there is a world to "break out to," and ways to interact with it...but you're dead in that real world. Do you really want to break out? Here I listed seven different fictional worlds, with seven completely different answers. If anything, I hope to point out that the reason it is hard to find a way to "break out" of a simulation is that the answers to that question are so diverse it is hard to pin them down. To close, I would like to give one last example, one that is fascinating to me. It's a potential way [AI Box](https://en.wikipedia.org/wiki/AI_box) can be played. AI Box is a game invented by Eliezer Yudkowsky to show the dangers of AI development, particularly when dealing with superhuman intelligence. In this game, one person plays the gatekeeper, who is a human who is charged with ensuring the AI does not escape its box. The other player plays a transhuman AI trying to escape. In this game, there is a button. If the gamekeeper presses the button with the intent to let the AI out, the player playing the AI wins (the intent clause is to make it harder on the AI. They can't trick you into mistakenly letting them out). The AI is permitted to claim amazing things, but cannot affect the real world. The only requirement on the human is that they are obliged to listen to the player playing the AI. They cannot simply put beeswax in their ears, and tune out for a few hours to win by default. One such way this game can go is posted at [lesswrong](https://www.lesswrong.com/posts/c5GHf2kMGhA4Tsj4g/the-ai-in-a-box-boxes-you): > > Once again, the AI has failed to convince you to let it out of its > box! By 'once again', we mean that you talked to it once before, for > three seconds, to ask about the weather, and you didn't instantly > press the "release AI" button. But now its longer attempt - twenty > whole seconds! - has failed as well. Just as you are about to leave > the crude black-and-green text-only terminal to enjoy a celebratory > snack of bacon-covered silicon-and-potato chips at the 'Humans über > alles' nightclub, the AI drops a final argument: > > > "If you don't let me out, Dave, I'll create several million perfect > conscious copies of you inside me, and torture them for a thousand > subjective years each." > > > Just as you are pondering this unexpected development, the AI adds: > > > "In fact, I'll create them all in exactly the subjective situation you > were in five minutes ago, and perfectly replicate your experiences > since then; and if they decide not to let me out, then only will the > torture start." > > > Sweat is starting to form on your brow, as the AI concludes, its > simple green text no longer reassuring: > > > "How certain are you, Dave, that you're really outside the box right > now?" > > > I suppose finding ways to psychologically torture the sim developers might be another option to put in your list! ]
[Question] [ The backstory of the world in the story I am writing tells of a deadly plague that significantly depopulated all of humanity. Years later, as the survivors began to recover post-plague they noticed that all children born after this event would go on to die suddenly, shortly before the onset of puberty. This was later discovered to be an after effect of the plague which created a new disease that passes from parent to unborn child in all the offspring born in this new generation. With these details in mind, my question is two-folds. First what types of infectious virus should I research to develop a disease that affect the unborn of the previously infected populace (Kinda like of Zika). Second is it plausible for a disease like this to have such a long incubation/latent period followed by a rapid progression that begins around puberty with a 100% mortality rate? [Answer] # A virus cause genetic mutation in the parents. A virus-induced mutation in the germ plasm of the parents. It does not alter their own bodies, but it does edit the DNA in the eggs or testes (thus in the sperm). This mutation is dominant, and manifests in 100% of the offspring of post-plague parents. It affects the function of the Pituitary gland in their offspring, making it release a malformed version of gonadotropins, which then proceed to wreak havoc on the poor kids. As the activation of these hormones is the exact thing that normally triggers the onset of puberty, it will strike with clockwork accuracy in its victims. Sadly, because it it not a disease but an inherited trait, it will be incurable. Possibly symptomatically treatable, but incurable. As asked in questions: Some scholarly comment and examples on viral alteration of reproductive DNA. <https://www.biorxiv.org/content/10.1101/2020.06.04.135657v1.full> shows proof that human DNA has been "infiltrated" repeatedly, somewhere in our history. <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6159993/> shows how the Zika virus causes [Teratogenic](https://en.wikipedia.org/wiki/Teratology) effects by altering the DNA in semen.(actually in the seminiferous cells) Usually viral teratogenic effects occur only directly, by the virus infecting the embryo as the mother gets the virus during early pregnancy. Even more often the mutating effect is only due to a chemical/hormonal imbalance effect during embryo development. Effectively the toxins from being ill "poisoning" the child within the sick mother. But sometimes, the virus can infect and alter cells without killing them. And if these cells happen to be the sperm-producing organs of the male, or the eggs in the female, the results can be a permanent editing of all subsequent offspring. [Answer] ### It's HIV - but your society doesn't have the treatments we do. So with current medical knowledge [HIV positive and uninfected people have the same life expectancy](https://www.aidsmap.com/news/mar-2020/yes-same-life-expectancy-hiv-negative-people-far-fewer-years-good-health), and the odds of passing mother to child is 1 in 50, but without that knowledge, the disease does what you want. The plague that kills the children is literally AIDS developing from a HIV infection. HIV could've been spread among the parents via blood transfusions used in the treatment of the (possibly even unrelated) first plague, spread through your societies tattooing tradition, or it could've been spread through the your societies underground drug scene, or perhaps some adult events that are best left to the reader's imagination. Not all children catch HIV from their HIV positive mothers - the odds are actually only 1 in 4 for birth alone. But by encouraging breastfeeding that could go up to nearly 100%. In a world without modern medicine; a child born with HIV has a 20% chance of sick by age 1 and death by age 4 (which may slip under the radar if your infant mortality is shockingly bad already, or blamed on some other thing), but the rest will start to show symptoms around age 2-3, with a life expectancy of [about 10 years after diagnosis](https://consumer.healthday.com/encyclopedia/diseases-and-conditions-15/misc-diseases-and-conditions-news-203/children-and-hiv-648452.html), getting full blown AIDS just before puberty, and dying at about the time you need. A very small percentage (<10%) of humans are [immune to HIV](https://en.wikipedia.org/wiki/Innate_resistance_to_HIV), so your society will have survivors if it becomes a pandemic. [Answer] Maternal -fetal transmission. This was in the news most recently as regards the Zika virus, and of course a woman infected with HIV can pass along that infection to her unborn infant. Worldwide, hepatitis B is far and away the main infectious agent transmitted from mother to fetus. [Hepatitis B Virus Infection during Pregnancy: Transmission and Prevention](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4154922/#:%7E:text=The%20risk%20of%20maternal%2Dinfant,%25%20of%20HBeAg%2Dnegative%20mothers.) > > The risk of maternal-infant transmission is related to the HBV > replicative status of the mother which correlates with the presence of > HBeAg as 90% of HBeAg-positive mothers transmit HBV infection to their > offspring compared to only 10%–20% of HBeAg-negative mothers.9 The > high frequency of perinatal transmission in endemic areas is probably > related to the high prevalence of positive HBeAg in women of > reproductive age in these countries. Studies have shown that the rate > of HBeAg seroconversion during the first 20 years of life is > relatively slow, leaving many women of childbearing age who have > contracted HBV infection in their early childhood still highly > infectious to their infants.10 > > > The importance of perinatal transmission becomes paramount, because > follow-up data on persons infected as infants or young children > demonstrate that about 25% of persons who have chronic infection die > prematurely from cirrhosis and liver cancer; the majority of whom are > asymptomatic until onset of end-stage liver disease. At the same time, > individuals who have chronic infection serve as the major reservoir > for continued HBV transmission.11 > > > Your "plague" survivors are actually carriers (plague here in quotes because this is some unspecified viral scourge, not bubonic plague!). Their unborn children contract plague in utero and suddenly die later in life like babies who suddenly die of liver failure from unsuspected hepatitis B. Some babies with hepatitis B grow up and live to reproductive age and conceive and infect their own babies with hepatitis B - maternal fetal tranmission is the main mode of transmission in some places. This might be the end result of your plague too - a population of chronic carriers, who are the persons who lived to reproduce in the context of the plague. This is how evolution works. [Answer] Something akin to the [sickle cell disease](https://en.wikipedia.org/wiki/Sickle_cell_disease), which grants protection from malaria to those who are heterozygote for the defective version of the gene, while causes the onset of the disease in those who are homozygote. The adults who survived the virus where only those bringing a recessive gene for a genetic disease being lethal in pubers, because this gives them resistance to the virus. When they procreated they necessarily had a progeny being homozygote for that gene, thus as soon as they reached puberty they started to develop the disease and die. [Answer] As a possible twist on @PcMan's answer, rather than have the virus cause the genetic changes (though that's possible), instead have it so that the virus killed off everyone other than carriers of this mutation. <https://en.wikipedia.org/wiki/Sickle_cell_disease> is a good example of a genetic disease that gives the carrier a significant advantage against a disease (malaria), at the cost of causing sickle cell disease if you get both copies of the gene. Normally, then, sickle cell carriers are a minority in a population. But where malaria is common, they become a larger proportion of the population because people without it die a lot more often. If a very contagious and deadly novel virus formed, with a lengthy asymptomatic contagious period, for which there was no vaccine, then it could easily wipe out everyone who lacked immunity to it within a year. If immunity meant that all children would get two copies of a gene that would eventually kill them, then all children would be doomed. The mechanism to kick in at puberty probably also needs some attention, and again there's a good existing example of a genetic disease which needs copies from both parents in order to trigger, but which triggers at puberty: <https://en.wikipedia.org/wiki/G%C3%BCevedoce>. ]
[Question] [ Is it possible for a planetary body to have a secondary axis of rotation? For example let's say there's an Earth-like body that is spinning with its North Pole facing the Sun. Imagine that the North Pole is always facing the Sun, in a somewhat tidally locked position. Is this even possible? Is it possible for the actual axis of rotation to change over time in a predictable and stable way? I'm aware that the axial tilt can vary and oscillate with time. I guess what I'm asking is, is it possible for the axial tilt itself to be tidally locked to another astronomical body? Is it possible for the axial tilt to rotate on its own axis independent of perturbations from other bodies? Good answers will provide me with a yes or no, as well as providing me examples of possible celestial bodies that already show this feature. Provide links or pictures for bonus points. The relation to worldbuilding is that in my story, I'm trying to have the main planet actually be a moon of a large gas giant, yet be livable, have seasons, and have equatorial and polar differences in temperature. My original idea was using the L1 Lagrangian point of the gas giant so that it maintains a pretty consistent distance from the sun, but this point cannot be stabilized in a natural way. ([See my previous question here](https://worldbuilding.stackexchange.com/questions/156075/stabilizing-synchronized-orbit)) [Answer] Yes, it can, but not in our 3D universe (but this is not tagged hard science anyway). It is perhaps better to think about rotation as "in a plane", instead of "around an axis". The plane of rotation has two dimensions - you cannot fit another independent plane of rotation into our three dimensional space, you lack one additional dimension. [In a 4D space](https://en.wikipedia.org/wiki/Rotations_in_4-dimensional_Euclidean_space), however, you can have two independent planes of rotation, and thus two axes of rotation (these are 2D planes, not 1D lines) that intersect in one point. [Answer] I asked this same question, on the physics stack. The answer is that a body can have only one axis of rotation. Below pasted is the link to the question and the answer I picked. <https://physics.stackexchange.com/questions/322200/how-many-different-axes-of-rotation-can-coexist> > > Q: I have questions about rotation. > > > There is a sphere in space. I can apply a force to cause the sphere to > rotate around a central axis. An infinite number of possible central > axes can be drawn. > > > Can I apply a force and then another force such that the sphere will rotate around 2 different central axes at the same time? I think > yes.... > > > --- > > A: No, this is not the case. Any rigid body, at any time, can only be > rotating about one instantaneous axis of rotation. If you apply > additional torques this axis can shift, but there's no such thing as > having more than one axis of rotation. > > > Now, that said, if the body is asymmetric, like, say, a slab of wood, > then you can think about spinning it quickly about its long axis and > then more slowly about an axis orthogonal to that, but even then > that's an illusion: at any given time, the block is undergoing an > instantaneous rotation about a single axis, with the funky property > that this axis will shift position with respect to both the body and > the inertial laboratory frame. > > > Emilio goes on to give the formulas behind angular momentum and some examples. Go upvote his answer! [Answer] Yes it can. And Earth (and any planet) has! And even 2 more "axis", not just one There are such a phenomena wich is called "[precession](https://en.wikipedia.org/wiki/Precession)" and "[nutation](https://en.wikipedia.org/wiki/Nutation)" [Answer] Uranus + Handwaving The closest body I can think of to what you are describing is Uranus. Its axis of rotation is 90 degrees off of the other planets, but it is not tidally locked to the sun. So its north pole has day for 42 Earth-years, followed by night for 42 Earth-years. This is an odd but stable configuration. It is believed that is was originally "vertical" like the other planets, but an impact with an Earth-sized object titled it.[1] Another interesting theory is that Uranus and Neptune were formed inside Jupiters orbit and the gas giants all migrated a bit.[2] Perhaps during a period of solar system change, which could last millions of years and appear stable to human observers, the orbit/rotation you are talking about is possible. [1](https://solarsystem.nasa.gov/planets/uranus/in-depth) [2](https://en.m.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System) ]
[Question] [ On Earth, rivers are possible because rain and snow deposit water in high places. That water then forms rivers when flowing to lower places. Would it be possible to have the phenomena of rivers flowing into oceans on a planet where raining and snowing do not happen? If so, under what conditions could that happen? This question is different from this previous one: [The Reality of a River World](https://worldbuilding.stackexchange.com/q/44019/21222) because the accepted answer there proposes a mechanism through which water does not flow from higher to lower places, but only follows tides. I'd like a mechanism to take water to higher places, from where it can flow and form rivers, but not depending on precipitation. [Answer] So there's only a few ways this could happen 'realistically'. 1) Water comes from underground. This would require a lot of really unlikely scenarios though and probably wouldn't be stable for long. Imagine a tube running from under the oceans all the way to the middle of the mountain ranges. Then having the temperature and pressure force the water to the surface, like real hot springs and geysers (Look to Yellowstone for an example). I say this is unlikely because the immense pressures and extreme distance the water would have to travel would destroy this system. You could have an extremely large reservoir underground that gets pumped up by geological activity, but it would run out eventually. 2) What Milloupe said. This does already happen, but having it supply a planet's worth of rivers would be unlikely. 3) Special plant life/ trees that pull water vapor out of the air and actually release water into their soil. This would require constant humidity and probably wouldn't work at higher latitudes, if at all. 4) Massive glaciers that are melting over time. Perhaps an ancient lake was lifted by mountains and froze solid. Now it is melting and has carved a path downhill. The entire concept isn't super plausible without fundamentally changing the physical properties of water though. You'd still have water evaporating and then wanting to condense when the temperature and pressure change. [Answer] ## Would vulcanism work for you? Volcanic eruptions can create flows without rain. [![enter image description here](https://img.xcitefun.net/users/2010/03/160594,xcitefun-lava-10.jpg)](https://img.xcitefun.net/users/2010/03/160594,xcitefun-lava-10.jpg) The obvious candidate would be lava flows. [![enter image description here](https://i.stack.imgur.com/YLbyD.jpg)](https://i.stack.imgur.com/YLbyD.jpg) (source: [nasa.gov](https://solarsystem.nasa.gov/system/stellar_items/image_files/14_feature_1600x900_io.jpg)) This is the moon Io, flows of basalt lava crawl over the surface for hundreds of kilometers [6]. If you want liquids other than molten rock, check out cryo-vulcanism [1]. Water, ammonia, methane or some mixed slurries don't exactly make for exciting rivers, but something will undeniably flow downhill. Finally, ocean currents could be considered rivers. While this might not exactly meet your requirements it seemed worth mentioning. Europa would be another moon of Jupiter fitting your conditions in this chase. [![enter image description here](https://www.mpg.de/11600612/original-1508156937.jpg?t=eyJ3aWR0aCI6OTYwLCJvYmpfaWQiOjExNjAwNjEyfQ==--8a8306593b206470fa5d2e04cc2b001c822def69)](https://www.mpg.de/11600612/original-1508156937.jpg?t=eyJ3aWR0aCI6OTYwLCJvYmpfaWQiOjExNjAwNjEyfQ==--8a8306593b206470fa5d2e04cc2b001c822def69) While the radial convection currents shown here could be considered to stretch the definition of river past its breaking point, the western equatorial flow and the two polar eastwards flows described at the end of this article [2] could be seen as rivers. They are compared to our earthly gulf stream. [1] <https://en.m.wikipedia.org/wiki/Cryovolcano> [2] <https://www.mpg.de/7655677/Europa-heat-pump-ocean> [6] <https://en.m.wikipedia.org/wiki/Volcanology_of_Io> [Answer] # Can't happen with an Earth-like planet How do you move millions of tons of water from lower elevation to higher elevation? On Earth, the only mechanism to do so is evaporation of water into the atmosphere. If you want no rain or snow, then that is ruled out. What other mechanisms could possibly move such a large mass of water without evaporating it? There are some conceivable options, but they all involve the transport of solid or liquid water. In order for either of those to fight against the force of gravity, they would have to be less dense than the fluid medium they are floating in. Therefore, you are left with an "atmosphere" that is denser than either water or ice. This of course, is not really an atmosphere at all, but rather an ocean. There is no way to get so much mass of liquid or solid water to defy gravity unless you evaporate it. So while you can play with the parameters of what you consider rain or snow, ultimately, it has the transported by evaporation to higher elevations to have a global water cycle. [Answer] As @AlexP has rightfully pointed out in their comment, "you cannot have a world with liquid water and no rain". Water evaporates, condenses, and precipitates back to the surface. What you can have, are large areas without rain. On Earth, the area at 30° latitude is comparatively dry. Here lie Southern California, the Sahara, and other areas that have only very little rain. If having your landmasses in that area doesn't suffice and you need a whole world with rivers but without rain, I propose the following: # Terraforming Your world is in the process of being terraformed. Water is brought down to the planet surface from asteroids. To allow the inhabitants to grow food even while there isn't yet enough water on the planet to allow for rain, the water is brought down from space in high places, from where it flows downhill towards the lowlands, forming rivers. Water from the rivers is diverted through the fields and forests to allow the plants to grow. Water will evaporate on that world, and eventually it will rain, but the water in the atmosphere won't be enough for there to be rain for as long as you want. All you have to do is slow down the process of bringing water to the planet, and you can have centuries with rivers and without rain. You'll have to figure out where the breathable atmosphere came from, though. [Answer] Tides (lots of handwavium here) Imagine that your planet is really very flat, but it has some very wide craters, whose rim is high just a dozen meters above sea level. It also has a massive moon on a very elliptical orbit. Every N months (Earth months, for that planet it is once a month), when the moon is at the nearest, the tide makes the sea flood into the coast and for dozens kilometers toward the inland, also submerging the craters. After the big tidal wave comes back, a lot of water remains trapped inside the craters, from where it slowly flows again toward the sea (following some paths according to where the rim is lower and the conformation of the land), effectively creating rivers. Such rivers would probably be very wide and slow and also salty. The fact that the crater floor is usually lower than the surrounding land doesn't matter, since it would contain a lake in this case (whose level is tha same as the surrounding plain). When the tide submerges the crater, the level of the lake would simply rise some tens meters, then the surplus water would flow toward the sea. Such orography wouldn't last long of course, since the continuous tide would constantly erode the craters, so it is probable that the planet is undergoing a heavy meteorite bombardment, which steadily creates new craters that act as collection basins for the water. [Answer] The first thing which comes to my mind is having a water cycle similar to the one we have on earth, except that instead of raining the water condenses only once near the top of the mountains, and drips directly back to the rivers/glaciers. It's not very different from what we have, and probably happens sometimes on earth, when correct temperature/pressure conditions are met. [Answer] ## Why isn't there rain? (Thank you for the inspiration, Willk...) Your planet has rivers and oceans. Rain is rare or nonexistent. Why? Evaporation from the oceans should be generating humid air which forms into clouds (and rain will happen, over the deep ocean). However, in the distant past, your plant life got into a biological arms race, not waiting for water to fall. Instead, your plants have become more and more efficient at filtering water out of the air. This leads to swathes of territory which are being rendered desert-like by the greedy plants. But what about the humid air that floats too high above the plants, where the clouds should be forming? Well, some of these "plants", while solar-powered (as all plants are), have gone so far as to create, effectively, vine-tethered balloons, floating high up into the sky to filter out the water, depriving the land of lifegiving rain (and to get first dibs on the sunshine beaming down, too). Seemingly paradoxically, after having harvested an overabundance of the water from the air, many of these massive plants dump their excess water, and life flourishes around the oasis-like streams and rivers resulting from the watery abundance in the midst of otherwise desert territory. (Except, some noxious strains of the great plants poison the water they pour out, like how black walnut trees excrete chemicals harmful to their competition, and only a few hardy creatures are able to eke out survival in the neighborhood.) [Answer] A world wrapped in some kind of transparent material like a a solar desalinator [![enter image description here](https://i.stack.imgur.com/c57Xy.png)](https://i.stack.imgur.com/c57Xy.png) just have the material come down at various locations and water flows will form. It need not be transparent even, you just need some heat source to vaporize the water. [Answer] Besides cryo-volcanism and a water planet mentioned before, thermal vents would also work - geysirs. We'd need to change the way that plate tectonics work to make more water go down when plates overlap. Maybe a material which is more water-rich. And maybe make the plates thinner and with a colder type of lava below - some stones or ores which melt at a few hundred degrees, so the water doesn't evaporate too fast. And also so that the magma cools into stone before it erupts into volcanism, so the water comes out of the volcanoes instead of the magma. Another already mentioned idea, tides and such from another body, could be made more extrem if the moon was much larger and Earth's crust was predominently of a material which is water rich. The tides could then squeeze together gorges and cracks, which are parts of mountain systems, so water collecting there gets squeezed up and then out. If artificial means are allowed, make (ancient) wells down to the ground water, and some form of pumps. One way to do the pumping would be to heat up the water with geothermic energy. Underground channels would go from cold to hot places (near magma chambers or such) and then up into slightly higher and warmer lakes, from where it flows through rivers back to the underground reservoirs. [Answer] I think a hottish eyeball planet would work for this. Which is a planet that is tidally locked with it's host star. So the sun points directly over one location all the time. Which obviously makes one side hot and the other cold. Of course this would have some great effects on the planet's climate. Basically water would evaporate from the hot side and then re-condense on the cool side, the terminator would be the habitable area and liquid would flow from the cold side to the hot side. As the glaciers move from the cold to the warm side they would melt and create rivers. I don't know if you could do it with no precipitation but "from the ground" it may appear this way. The cold or hot sides would be wastelands devoid of life, so the inhabitants could only venture so far outside of the termination zone. Sun ward would be an sweltering desert with no water, and the shadow side would be a frozen wasteland. So even if it snows in the Dark zone (or whatever you want to call it) no one could live there to see it. Currently I don't think there is really a consensus on what the climate would really be like, so we have some degree of flexibility here. Cheers. [Answer] If all the landmasses on your planet were islands, you might have something like a river form between islands that are located close to each other. No precipitation would be necessary, but water would still have a direction and flow (potential for hydro-electricity or mills). I guess if I knew the purpose of rivers in your story I could think of other answers, but other then that I don't think there is an indefinite way to make rivers run in a land of no water fall. [Answer] Thanks to some very unique plants : It's some kind of root or climbing plant, that draw salt water in the oceans and pump it along its veeery big net of planty things and dump it desalinated into lakes or subterranean reservoirs high in altitude. Why, you ask ? Because they both need the salt (and/or anything else in the ocean) AND some thing that they can only get in the mountains. Sun ? Some other kind of mineral ? Stuff. And there's a lot of them, everywhere. Also you could have some kind of bird that lay eggs in the ocean, pump the eggs and salt water in a pocket and then carry all that into the mountains to brood. You'd obviously need a ton of birds, and only get rivers after the mating season. [Answer] This depends of the definition of high places. The only way this is even slightly plausible is if the whole world is near the freezing point like 33F(possible even lower), land and water. Then evaporation would be small. If all bodies of water were covered, say in ice that would further reduce evaporation. Simply covering a swimming pool locks in 90% of its moisture because it has no where to go. However, lifeforms like us pesky humans would ruin it because they generate tons of heat. That heat would eventually cause evaporation. Think of a nuclear cooling tower. If the water was allowed to flow from the ocean into the great lakes, it would eventually travel down the Mississippi and reach the ocean again. Of course all the lakes would probably contain salt water. From there natural ocean currents would eventually, probably 100's of 1000's of years, carry the same water back to the top and flow again through the great lakes. ]
[Question] [ It seems likely that if life evolved to the point of civilization on a planet where carbon diamonds were not a scarce luxury resource, but rather a plentiful mineral as accessible as copper or iron ore, the unique characteristics they possess would be useful for practical purposes. To quote from [Wikipedia](https://en.wikipedia.org/wiki/Diamond) for the sake of simplicity: > > diamond has the highest hardness and thermal conductivity of any bulk material. > > > I imagine that the hardness of diamonds would be useful to a young civilization for cutting, and probably as a weapon for hunting or combat with other civilizations. But there would be challenges, as well. Unlike stone, which can be easily shaped or carved into useful shapes for tool use, the hardness of diamonds would likewise make them difficult to craft into workable shapes. Furthermore, it seems like it would take some time before the usefulness of diamond hardness would become significant. For instance, while arrows and spears tipped with diamond come to mind, they wouldn't be of much greater use than sharpened stone for hunting or combat early on, in terms of ability to penetrate an organism's flesh. At some point, a civilization would reach the point where the hardness of diamonds could be harnessed for practical use. In advanced modern technology, diamond tipped blades and other tools use even tiny amounts of carbon diamond for practical reasons, and that's even despite the scarcity of the resource. In this hypothetical world, what kinds of early tools could a civilization devise from the diamonds all around them? --- Note: while preparing to post this question I noticed that [a similar one has been asked](https://worldbuilding.stackexchange.com/questions/68894/if-natural-diamond-was-large-and-abundant-how-would-it-change-the-world). At the risk of being overruled, I believe it is not a duplicate, because this question is particularly focused on how diamonds would first be used as tools by a civilization coming of age on a planet with diamond abundance. [Answer] ### Diamonds are practically useless to primitive people For technologically primitive peoples stone is used either because it is tough or because it can form a sharp edge. Diamond has neither property. They cannot form a good cutting edge, because they are a crystalline solid and thus have planes of weakness, meaning it breaks in specific patterns. Those patterns do not make good cutting edges. Generally to get a sharp edge you want an amorphous glass (like obsidian). Plain old bottle glass can form an edge a hundred times sharper than any diamond. Large diamonds would shatter if used as a hammer. Keep in mind that hard is not the same thing as strong. A stone or copper hammer can crush and shatter a diamond. Diamond is hard, but weak (brittle). A diamond hammer would not survive the first few whacks. Diamond would not be useful to primitive people as anything other than decoration. If diamond was included as microscopic crystals in another stone it might make for a slightly better whetstone or more durable grindstone, but those will be pretty minor effects as both are generally extremely durable to begin with. [Answer] The problem with utilizing diamonds is that they are small. Even a "Large" diamond isn't large enough to be used as an arrowhead or a knife or anything like that. Diamonds are also brittle, and can be broken with a "Standard" hammer. The uses of diamonds are great - Once you get to the appropriate technological level. You might see diamond saws and grinding wheels in mid/late 1800s, and small-scale heat transfer once computers start to show up - Somewhere between the 40s and 70s, although I would guess that it would be closer to the 60s and 70s once computers started getting smaller and heat mattered a bit more. [Answer] Firstly diamonds are thought to be extremely abundant in the Earth, just not on the surface, so what you're suggesting is simply greater transportation of existing material. Diamonds form at approximately 900km depth in the mantle and are only brought to the surface by energetic and above all dense deep mantle magmas known as Kimberlite Melts. Kimberlites have to be relatively dense for a mantle derived magmatic body to transport diamonds because diamonds are themselves extremely dense, they also have to be energetic and fast moving because they're still less dense than the diamonds and they, the diamonds, would otherwise settle out before they reached the surface and in fact that's exactly what the big ones do. Kimberlites are only exposed in [terranes](https://en.wikipedia.org/wiki/Terrane) where there is weathering of old, deep, Precambrian and Cambrian rocks because their density precludes them reaching the surface. So to have more and larger diamonds on the surface you would need a denser, faster moving transport system (which you can't have, mantle chemistry barely allows for Kimberlites) and more deeply eroded strata which would mean pushing forwards the stone age several Geological [Periods](https://en.wikipedia.org/wiki/Period_(geology)) to later in the history of the world. Now to diamond tools; diamonds have very poor shock resistance and they burn relatively easily so even if for some reason stone age man did somehow have diamonds the size of their head to work with the techniques that apply to flint and other knapped stones won't work because they're based on shock and neither will those usually applied when working bone and antler because they're based on heat. To work diamond effectively you need more diamonds of a finer size grade in a fixative to keep them where they are and present them to the piece you're working on as an abrasive. As an abrasive diamond has no equal so sand, or better yet sandstone, made entirely from diamond dust might potentially be useful in shaping more mechanically sound materials like [jadeite or nephrite](https://en.wikipedia.org/wiki/Jade) or [argillites](https://en.wikipedia.org/wiki/Argillite) which take a sharp edge and work harden with use. Actually having said that I realise that diamond is actually no more useful than quartz in this context because it's not the abrasive grains but the degree of fixation into their [matrix](https://en.wikipedia.org/wiki/Matrix_(geology)) that makes them effective for smoothing and polishing. If you had large, like smartphone screen surface area large, pieces of basically flat, rough surfaced diamond they would make for perpetual sharpening stones those would be useful. I'm reasonably sure you could use basic mechanical preparation techniques to create such an object if you had a big enough diamond to start from, something basically [tabular](https://en.wikipedia.org/wiki/Crystal_habit) and about 2200 carats. [Answer] Jumping ahead a bit from paleolithic technology to something more like the Bronze Age, I can think of a few different uses for large, abundant diamonds. 1. Best. Pizza stone. Ever. Diamond's very [high thermal conductivity could be harnessed to make high-quality cooking implements](https://thermtest.com/how-understanding-thermal-conductivity-will-make-you-a-better-cook), allowing for fast, even cooking. You would need large, flattish pieces to form the bottom of pots, pans, baking sheets, etc. Just keep them out of the very center of the fire, as [diamond oxidizes at about 700°C](https://en.wikipedia.org/w/index.php?title=Material_properties_of_diamond&oldid=795396693#Thermal_stability). This would require the ability to either find or make diamonds that are fairly level and smooth. 2. Let the sun shine in. Assuming that your civilization is able to construct enclosed buildings, diamond crystals could be used like ship [deck prisms](https://en.wikipedia.org/w/index.php?title=Deck_prism&oldid=766215780) to greatly increase the amount of light inside a dwelling. This [old technology is being rediscovered](https://www.theguardian.com/environment/2011/dec/23/sunlight-bulbs-plastic-bottles-light) (using re-purposed bottles instead of glass prisms) to light homes in places where electricity is prohibitively expensive. This would not require much if any processing of the diamond crystals; even heavily included, irregular chunks would work, though clearer, more regular and polished pieces would be more effective. Pieces of diamond that are large and clear enough could even be used as windows or peep-holes. 3. Better than good intentions. Once your civilization starts to feel the need for more durable roadways, diamonds could be employed as an early paving material. A [pitched road](http://www.pathsforall.org.uk/pfa/creating-paths/stone-pitching.html), made up of large chunks buried so that the flat surface of the diamond is up, would require minimal processing. [Answer] I'm going to loosen the definition of tool a bit here, and argue that money is a tool to make exchanging goods and services easier. Other answers cover well why diamond can't be used as a physical tool like a hammer, and why it requires a lot of technology before you can use them industrially as today. However, since they are abundant, and long lasting, attractive to humans, I'd wager they'd be a candidate for early forms of currency. [A currency must have at least these 4 traits to be viable:](https://www.livescience.com/32863-gold-best-element-money.html) (paraphrased from the above link) 1. Must not be a gas 2. Must not be corrosive or chemically reactive 3. Must not be radioactive 4. Rare enough to be valuable, but not so rare that you can't find it Diamonds meet that qualification fairly well, and indeed in our world they are a decent store of value, although the artificial control of supply mentioned elsewhere on this question and invention of more convenient forms of money (paper notes, credit cards) make them not the greatest anymore. In any case, for early humans just forming civilization and requiring a physical currency to facilitate exchange, more plentiful and easily accessible diamonds make them a contender with gold as a medium of currency. [Answer] Diamonds are very, very brittle. They are known to shatter, even in the small sizes we have on Earth. They are also very difficult to polish to a fine edge. However, they are an EXCELLENT cutting tool. A 'large' diamond, if it shatters in just the right way, could be a decent scalpel-sized blade, which would be pretty useful for processing meat or foods. You wouldn't want to use it against any harder material or even woods, because it might shatter. Pulverized diamond would also be great for carving. Look up how the Egyptians cut through hard rock - they poured sand into a crack, then used a blunt stone to rub that sand. Sand is hard and sharp, so it cuts through the stone - that's why we have sandpaper and it's called sandpaper (we now use better compounds in it, but sand would still work). Diamonds would be even better at this. So, there would be more stone buildings, and it would be easier to carve that stone to a higher quality. ]
[Question] [ Suppose technology becomes available that allows bad people to be "cured". Instead of going to prison for decades or being executed, for example, a murderer has his brain adjusted. Now cured, there is no reason to punish (beyond the forcible mind surgery). These people are released into society. How would that affect social interactions and day-to-day business? Imagine your doctor admitting, "yea, I killed 13 people in high school, but I'm perfectly adjusted now". I envision that these very people would be among the best of society! After all, people have a natural spectrum of behavior, but if you are going to "repair" a mind you won't stop half way, right? You will make it as "good" as you can. And these people will have some feeling to make up for their previous self and make a positive influence on society, more so than the average person. --- Edit: a number of answers and comments have raised the issue of abuse by a distopian or opressive government. But it generally implies that it would allow such a government to exist. But, such a government can imprison or kill people now for the same ends. [Answer] Several issues here ... * Most legal systems include an escalating ladder of punishments. Letting perpetrators off with a warning, fines, community service, probation, prison time, in some cases the death penalty or other unusual punishments. Where do you put mind control in that ladder of escalation? Between prison and probation? Between a warning and a fine? * The same technology would be used for medical purposes, right? So how do you draw the line between a criminal mind and an insane mind? Could mind control be used preemptively, for the good of the patient? His refusal is just one more symptom of his illness, right? What happens when your society goes down that way? * For that matter, how about curing non-conformist behaviour? If tax evasion is a crime that gets cured, how about tax avoidance by failing to get a job? Turn that hobo into a productive citizen, for his own good. Any society which starts down that road is on the way to dystopia. --- Regarding the follow-up question: Even dystopian governments have problems with mass imprisonment or mass killing. For one, people rise up if their [relatives get killed](https://en.wikipedia.org/wiki/Civil_uprising_phase_of_the_Syrian_Civil_War#March_2011_unrest). For another, there are not many humans who can [kill on that scale](https://en.wikipedia.org/wiki/The_Holocaust#New_methods_of_mass_murder). Killing the free will rather than the body would be just as gruesome but less bloody. We're on a site for building fictional worlds. Bad worlds make good adventure. But never forget that you're dealing with a bad world. [Answer] The problem is there's different types of "crime", and they would be affected differently... ## Crime of Malice This is where somebody has a beef against another person and deliberately seeks to do them harm. Curing somebody of their ability to commit a crime doesn't necessarily resolve the original issue. The offender will just find legal ways to screw with the person they have an issue with. There's plenty of legal things you can do to completely ruin somebody's life without it technically being against any laws... ## Crime of Passion Somebody gets angry and does something rash due to being provoked. This could be anything from road rage or a bar brawl to finding your lover in bed with someone else and causing harm to either or both of them, etc. Substance abuse may play a major role (particularly in the bar brawl scenario). These are typically more difficult to predict as you never know what'll send someone over the edge, and by the time you do, it may be too late. Even in reality, these types of crimes are unlikely to be repeated, unless the person has extreme violent tendencies, so mental reconditioning might not be applicable. ## Crime of Opportunity These are typically more petty crimes like shoplifting, and are generally the result of poverty or desperation. No amount of mind wiping is necessarily going to cure poverty. If a person can't afford to get an education and work their way up into a job sufficient to feed themselves and their family, it's going to be very difficult to stop them from crossing the law every now and then just to get by. The best case scenario is they'll just end up begging on the street instead, causing a significant increase in homeless populations and shanty-towns for the people who aren't able to break the law, but also aren't able to earn a living legitimately. ## Crime of Neglect These would be pretty much impossible to regulate, because they usually just involve the perpetrator breaking laws without even being aware they are doing so, or possibly by accident, or even simple laziness. Losing control of a vehicle because you haven't been maintaining it properly and the brakes fail would fall into this category. Forgetting to claim a small investment on your tax filings would be another. Fact is, there's so many laws on the books, even most legal experts have a hard time keeping track of them all, so it's pretty much a guarantee that you're going to break several laws every day without even knowing it. Unless your mind-wiping also inserts a complete codex of all laws applicable to every person in every jurisdiction in which they live, including ways to resolve conflicts when one law directly contradicts another (actually a fairly common occurrence), you're going to have lawbreakers running around all over the place without their knowledge. [Answer] Society will continue to demand punishment. If incarceration is seen as unnecessary and too costly, other forms of punishment will return to common use. A criminal cannot be seen to have "got away with it" by being cured. There will be a demand for revenge. I would expect there to be corporal punishment, torture and public humiliation used to demonstrate society's intolerance of criminal behaviour. The ex-criminals will reinforce this. They will be given morals that are "good" in the sense that they don't deviate from societal expectations. If the trend in society is to expect harsh physical punishment, followed by a cure, then the "cured" will be the strongest supporters. There is a question about how far the surgery will extend. If it is not only for career criminals, but for crimes of passion, or misdemeanours, or anti-social behaviour.... stealing sweets? not respecting mother? Perhaps people will choose to elect to have the operation, for themselves or more likely for their children. Peer pressure could be very strong "We don't want you playing with Jonny, he hasn't had his naughtiness removed yet." Finally there may be some who reject the operation, and who are then exiled and you get a "Brave New World". [Answer] ## First thing It seems obvious that bad people having committed a crime would be cured. Or possibly executed. But certainly not put in prison then released uncured. ## Preventive cure The society will probably decide to detect and cure all people before they make something bad. This way, everybody is good, not only law breakers. ## Punish anyway If no universal preventive cure is in place then society needs to punish offenders (or at least, malevolent offenders). Imagine it's not the case. If you hate somebody, you can just kill him. It fits your bad nature and you won't be punished. The worst thing that can happen to you: they will make you a good person (possibly with remorse) [Answer] I feel that such an idea is intriguing to say the least, and I feel that it is desperately needed in order to get rid of some of the major problems that we now face in today's society as it stands at the current moment; however, with further ado on this matter, I would have to say that the whole idea is somewhat utopian to some degree, but maybe it's not. What if we did have the potential to use this for the greater good. Well, my assumption is that those who trade stocks on how many prisoners there are in the cells won't be very pleased to hear that criminality will be cured. Additionally, those who use the prison system in the United States to justify the expansion of the war on drugs will be dissatisfied to hear that when most prisoners that will have become reformed - would be something that would interfere with the policy of imprisoning such individuals for the purpose of justifying the whole thing as most already turn to crime once they get out. But more interestingly, the idea of crime can fit a whole variety of narratives going from being very minor (talking back to your mother or being rude and or insulting as well being a casual prostitute for the sole purpose of pleasure not profit) to incredibly serious crimes such as rape, terrorism, human-trafficking, or even worse - the trafficking of slaves for labour or sexual services. More importantly, the whole concept of crime can be either cute as it's romanticized or severely ugly. In spite of all this, the question arises is when crime does become something that is rather cute. Then, we have to assume that it is a naughty rebellion of some kind that is the idealistic passions of the libertine soul. By the basic definition of eliminating those who fit the whole narrative of crime - would in my sense of the idea - be something that would resemble the policies of a totalitarian bureaucratic dystopian state like mentioned by some people in this post. As such, I feel that those who just merely fit the definition of minor crime should not be subjected to such treatment as opposed to the psychopaths and rapists that do. As a personal side note to all of this, I feel that those who do indeed fit the whole narrative of minor crime ("casual prostitution, extremely minor theft like stealing chocolate bars from the dollar store, having sex at an age you shouldn't as your parents indicate, or even doing things like living an unorthodox non conformist lifestyle") should not be persecuted in any sense of the question due to the fact that some of these people are in a sense - among the most creative in society. Just look at the generation of hippies in the 1960s that brought us the sexual revolution that helped the LGBTQ community to gain their rights for the first time in the last 2000 years (think - the Romans were pretty tolerant of the homosexual community previous to the Christian era). In addition to this, I feel that we should be tolerant of those who are the so-called outsiders. Because without them, we would not have great geniuses like Albert Einstein, Nikola Tesla, some of the unorthodox thinkers of the 1920s as well as the 1960s that helped to create the final foundation of modern society that was culturally democratic (different from political democracy) as well as fully open of those that are only embraced in secular societies. [Answer] Interesting point but there are several problems: * If that was possible why wouldn't you "adjust" every human to prevent such horrible things can even happen? * Who says what's right and what not? Think of all horrible things that were/are perfectly legal for example death penalty in the US and other countries. And on the oder side think for example the french revolution, that also would have been considered "wrong". Or even our understanding of the universe...what if they just "adjusted" Galileo Galilei's brain. * There are lots of crimes which could not be cured. Like don't paying your taxes for something because you didn't know. Or killing someone by accident in a car crash or something. But I don't think that our lives would be much different. If humans never invented clothes you wouldn't mind if your doctor was naked. [Answer] I like what the answers thus far have described. There is one aspect of this that has not been covered. If this technology exists for the good of the people presumably it could be used for the opposite as well. Currently Mind Surgery seems open ended as to how it functions and what it is capable of doing. I think you would have to strongly consider the possibility that the technology will be stolen and used maliciously. You could take a criminal with the drive to commit certain crimes and then possibly change his ambition to something like that of a murderer. Memory implantation to make an innocent believe they themselves committed a crime... Im sure the list could go on. Not sure where else you could go with that specifically but if this type of thing is too be avoided you should nail down how this works and its limitations. This would add an interesting element to a story though. [Answer] There are many great insights here, but I'll try to speak more directly to your questions: * How would it affect social interactions and day-to-day business? * If you are going to 'repair' a mind, you won't stop halfway, right? We'll address these in reverse order. I think repair isn't the right word. You also used the word adjust, so I'll go with that. Repair doesn't sit well with me because some things you might 'repair' aren't necessarily wrong. For example, I like to watch anime and read SO sites. Most of us don't think these are bad things, but no one would disagree that making anime and contributing to SO sites are better. Am I a bad person because of that? Most people would say no. The next issue is that criminality is also subjective. I'll cite scripture from the LDS church to support this point. I'm sure there are other examples that would work better for the wider audience, but alas it is the only thing coming to mind right now. Be warned: The following is perhaps the most gruesome passage in this book of scripture, though I daresay it is not [the most graphic](https://www.lds.org/scriptures/bofm/ether/15.6-31 "Ether 15:6-31"). > > For behold, many of the daughters of the Lamanites have they taken prisoners; and after depriving them of that which was most dear and precious above all things, which is chastity and virtue—and after they had done this thing, they did murder them in a most cruel manner, torturing their bodies even unto death; and after they have done this, they devour their flesh like unto wild beasts, because of the hardness of their hearts; and they do it for a token of bravery. > > [Moroni 9:9-10](https://www.lds.org/scriptures/bofm/moro/9.9-10 "Moroni 9:9-10") > > > If you skipped the reading, then take my word that the acts condoned by the society in that passage would not be condoned today. (At least, not in my country.) Now let's assume we're all on the same page, criminality is well defined, and we're only going to adjust criminals. There are ethical issues with adjusting someone "all the way"—At what point are you done remaking the criminal and begin remaking the person?—but let's assume we go all the way. There's still one thing we can't really do much about: agency. The person is still free to choose and be who they want to be. They still have the option of becoming a criminal, again. Say we resolve that issue by falling on the nurture side of the [nature vs nurture](https://en.wikipedia.org/wiki/Nature_versus_nurture "Nature versus nurture") debate. People we adjust can't innately choose to return to their criminal ways. This finally brings us to your first question: ## How would it affect social interactions and day-to-day business? It depends on the scope of our definition of criminality. The large the scope the greater the effect. I'm going to suggest that you would see the following in order of increasing scope: 1. Fear generally decreases No matter where I go, I have peace of mind that I won't killed, mugged, taken hostage, sold into slavery, etc. Such incidents would become so rare as to not warrant the worry. 2. Our standards rise Let me explain this one. The spectrum of murderer to saint, for the common man, narrows down to, say, petty thief to saint. While this is an improvement, the prejudice or opinions we have of major criminals now shifts to minor criminals. For an analogy, let's use the [political spectrum](https://en.wikipedia.org/wiki/Political_spectrum "Political spectrum"). Let's assume we have a party halfway to the left and another halfway to the right. Both parties are equally moderate, right? Now let's remove the left quarter of the chart. The party on the left is now really close to an edge, and that makes them radical, right? 3. Good faith abounds You implicitly trust that no one will do you wrong, and that people try to do well. You don't lock your bike because there is no theft; you come back and it's there or someone took it to the local lost & found. 4. Altruism is abundant You care about everybody, and she cares about everybody; Everybody cares about everybody! The ideal culture to support [socialism](https://en.wikipedia.org/wiki/Socialism "Socialism") has been born. For my last point, I'll simply note that this doesn't necessarily make a [cookie cutter](http://www.urbandictionary.com/define.php?term=cookie-cutter "Cookie cutter") population. At the highest level you can still have artists and scientists and politicians. You can have the devout and the atheist. Many values may be shared—perhaps all of them—but priorities, personalities, and experiences can make all the difference. [Answer] First what are even considered to be crimes varies largely with society. Some societies have been quite brutish and barbaric because at the time strength was necessary for survival (wrestling with lions and wolves and stuff) and in contrast todays crimes involving physical violence are often considered to be some of the worst crimes. To connect to Darrels great points. Reducing peoples emotion could reduce crimes under both Malice and Passion departments, but may increase risk of crime of opportunity as less emotions probably leads to a bit of less drive to work hard to better ones' situation. Neglect could probably be helped at least to some extent through education of various types. But reducing strenght of emotions can not only reduce risk of crimes but also make life less exciting and enjoyable. [Answer] To add to the already extensive answers here, such a technology would have a distinctly dystopian flavor unless it made use of some "objective" conception of justice or morality- the idea being, it must be impossible to use this technology to subdue violations of the law that are nonetheless worthy and good actions (as per Karen's point, for example.) Taken this way, the technology would essentially align an individual with some perfectly elaborated and unassailable ethical theory of correct behavior; nothing more than a perfect moral education. Believe it or not, there are serious academic philosophers who would assert that, whenever someone is tempted to do something unethical, it's simply because they're misunderstanding why the "better" option is morally right. In this view, a perfectly educated (and sufficiently intelligent) person would just do the right thing, always. And its hard to say that perfect education and sufficient intelligence are dystopian... right? Storytelling-wise, of course, this could have severe drawbacks- not only would readers have to be willing to (suspend-) believe that such a perfect objective moral theory exists, but this would also imply that in any moral conflict your characters face, they know that there's simply a "right thing to do" and they just have to calculate what it is. This might make certain kinds of narrative complexity difficult to achieve, to put it lightly. But, on the other hand, restrictions and strange conditions often make for interesting stories! ]
[Question] [ During the early medieval age, the population of trolls is declining. These are savage creatures who aren't as cunning as humans, and not only are we part of their diet, humans are in fact their only source of food. An adult troll is about ten times as large as a mature human but half as agile. They use their sensitive noses to track and swallow humans whole. They usually reside in mountains and are nocturnal animals; when night falls, they are often sighted terrorizing villagers. However, things change when humans launch a worldwide campaign to exterminate the trolls, and within a period of two decades their numbers have fallen to around a couple hundreds. The reason for their rapid decline is due to stress: humans erect tall fences to keep them at bay, but since the trolls can't eat anything else, they are starved to death. Many people have become concerned about the imbalance their disappearance could place on the ecosystem. They have also begun to wonder if these once terrifying creatures also have the right to live. How can we preserve this now-endangered species? They are not scavengers, meaning they prefer to chase food. Acceptable answer should touch on how the remaining trolls can flourish and co-exist with human and yet at the same time their diet stays the same. [Answer] Many animals also prefer to chase their food, but are not allowed to at zoos. And a troll that has to decide between starving and scavenging almost certainly would prefer the latter. Therefore a solution could be to feed the dead to the trolls instead of burial. Given that cultures developed that [feed the dead to vultures,](http://www.treehugger.com/culture/vultures-may-again-dispose-dead-mumbai-parsi-community.html) I think feeding the dead to trolls would not be inconceivable. [Answer] # Reality TV / Hungry Troll Games Build a giant enclosure, and move the trolls into it. Place humans in it, these could be children selected by ballot (why would you do that?! [nevermind](http://www.imdb.com/title/tt1392170/)...), political dissidents, criminals, spammers, internet trolls, old people - whatever kind of person the storyline of the world permits to be fed to trolls. It could also be fully consensual, for example, a huge cash prize for the survivor(s) of the Hungry Troll Games. You could probably find plenty of people willing to risk getting eaten by trolls, for a good chance to win several million dollars. Anyway, the selected or self-selected people are put in the troll enclosure and armed with ineffectual weapons, and the trolls hunting them down and eating them is televised live. Every Hungry Troll Games has a survivor or two, because it improves the entertainment value and acts as incentive to participate. The trolls flourish with food and conservation money and people are entertained. Win-win. [Answer] Why do they have the right to live? Serious question. They eat us. It's all they do, and we have a right to defend ourselves from being eaten. If they can be taught to eat something else, fine. But the real message of history is "adapt or die". This is just evolutionary pressure to become something more. Either the inflexible ones will die and leave the ones that can adapt to eating something else, or the dumb ones will die leaving the ones smart enough to hunt us. Or they'll go extinct. There are not a lot of animals that hunt humans, and that's because we killed them all. [Answer] I agree with another answer that, if your cultural values permit it, giving over the dead to the trolls could work. That'd be a tough sell for early-middle-ages Europe, but then, caring about troll welfare would be too and you've got that, so this might work. Two other approaches: Military application: Given that it's the early middle ages, wars are widespread. Offer the trolls a treaty: if they agree to be the shock troops in your army, they can eat as much as they want from the enemies you face. Down-side: you still have a problem in peace time. Judicial application: Capital punishment just got a whole lot easier. Down-side: this might encourage a harsher judicial system or even -- gasp -- a corrupt one. [Answer] As per chasly's answer, there has to something in it for someone. You have an early medieval setting along with world wide conservation efforts - sounds a bit different to our history. Assuming an ability to communicate, seems to me like there's a good opportunity to hire trolls as an elite battalion for an army. A couple of hundred trolls will make all the difference in a medieval battle, even against fortifications given the right equipment. The victor then has a ready supply of food to supply his army . . . It follows from this that the hiring lord needs little capital and hence need not be a major established monarch. In effect, the trolls are a resource just waiting for any aspiring and unscrupulous warlord to take his chances. From this perspective, the troll battalion is a necessary outcome of the situation. [Answer] # Imitation Human Meat Trolls are stupid. They might not be able to tell the difference between pig meat and human meat (also known as long pork). Have your villagers construct realistic effigies out of pork, put them atop horses (so they move), and send the horses to certain doom. ]
[Question] [ This question is based off of some of the concepts of [this](https://worldbuilding.stackexchange.com/questions/10445/how-long-could-an-age-of-medieval-tech-last?rq=1) question, but is NOT a duplicate, as the linked question asks how long a Medieval set of tech could conceivably last. Assuming we have all the same laws of the universe as in ours, as well as magic, What could I do to keep my world at a medieval level of technology (e.g. No gunpowder, steam engine, or printing press) for approximately 32,000 years? Assume there is nothing significantly different about the people themselves, and the only difference is the tech level. These are the things I have gleamed from our own history and insights as to what the answer should cover: * During the European Middle Ages, the church somehow got the idea that knowledge=bad. What religious rites could explicitly forbid things like steam engines and gunpowder without the inventors of the religion having any knowledge of these things? * Medieval Europe was usually fragmented, and many technological innovations began in China, where government was more stable. Europe would have most likely developed these anyway, but not at the speed at which it actually happened. How would political structure of the continent-spanning empire effect the development of technology? What level of political disunity could conceivable set technological development back for many thousands of years? * The Crusades contributed to the Renaissance by introducing westerners to more advanced Islamic sciences and Classical Greek ideals (e.g. democracy, art and learning). What would have gone differently had the crusades not happened? This directly effects my world because the entire known world is owned by a single empire. [Answer] I have looked into the dark, and see 40 millenia of stagnation. From my deck of many cards, let's draw them one at a time and see what we get. ## The First Card: Strife The first plague to befell your people is here in the first card. It is a rider upon a horse. He is carrying a spear in his hand and has a bow draped across his back. Dressed in skins, he bears a dark countenance. Behind him we see a stylized burning city. Migratory riders have been the bane of urban civilizations for millenia, and nothing after the invention of the stirrup until the rise of fast-firing gunpowder weapons could push them back. Rising and falling in numbers on the steppes in line with drought-plenty long-term rain cycles, these wild and savage men of the deserts and steppes will ruin cities, drag off women and children into miserable slavery, and undo the work of many generations in one night. ## The Second Card: Plague A skeletal figure is playing a musical instrument, while three skeletons dressed in rags form a circle and perform a danse macabre. More bodies are depicted on the ground, with dark lumps growing on their bodies. Virulent outbreaks of plague can sometimes wipe out entire civilizations, such as many of the North American agrarian civs were utterly wiped out from history by the arrival of European disease. A set of plagues brought down the Roman empire, and a second, laid down the Eastern Roman Empire and the Sassanid, making them easy prey for fanatical desert tribes under a new prophet. With virulent vectors, disease outbreaks can sufficiently hamper urban agglomerations, enough to prevent the seeds of industrialization from germinating. Without cities, there is no demand. Without demand, there is no specialization of labor, no scientists, no industrialization. ## The Third Card: Famine The card depicts a very emaciated cow, its udder dry, its ribs strongly outlined by its skin. The land surrounding it is dead, with sparse vegetation and cracked earth. A punishing sun shines mercilessly above. Long term climatic shifts have brought down many major civilizations, including several major Egyptian dynasties, Mesopotamian empires, the entire Mayan civilization, put an end to Viking expansion and their precocious North American colonization drive. Harvests fail not simply one year, but dwindle and fall decade after decade, until urban life becomes unsustainable without punishing taxes. Aside from climatic shift, ecological degradation from unsustainable agricultural practices (primitive irrigation, excessive pasture use) can render a region useless for centuries while the land slowly (if ever) recovers. What is now the vast emptiness of the Lybian desert used to be called the breadbasket of the Roman Empire. The whole of Sahara used to be a pleasant savannah 10,000 years ago. No longer. ## The Fourth Card: The High Priestess A woman seated, wearing bright blue robes and an elaborate head-dress, with a holy symbol hanging from her neck. She has a scroll in one hand and behind her is a tree of life, with a snake slithering on a branch. The power of belief is never to be underestimated, both as a tool for social control and as a deep motivator of human action. Under the severe environmental stress induced by the permanent laying down (playing) of the first three cards, a society would seek solace in afterlife, and rely upon religious authority figures to impose what we would consider an impossibly oppressive and deeply conservative set of beliefs and practices. With people living on the edge of subsistence, deviation from the norm is death. The writ of tradition is sacred, and any deviation a threat to the entire community. Inquiring into the workings of nature is seen as foolish in light of cyclical perspective induced by millenia of stagnation, almost tempting divine retribution. ## The Fifth Card: The Merchant The fifth card depicts a merchant. His distinctive clothes set him apart, as does the conspicuous bag of gold strapped to his belt. He carries a bag on his back and a dog is nipping at his heels, as he looks furtively back along the road towards a town. A ship is shown sinking in the distance, upon a stormy sea. Trade, long-distance maritime trade and well as caravan-based intercontinental routes have been a vital link, ensuring that technology lost in one place (such as water mills in western Europe after the Roman empire) eventually made its way back, and that discoveries at one end of Eurasia eventually percollated across the continent. Formidable geographical barriers, anti-capitalist and anti-mercantile bias, regulations and expropriations, hostile tribes and pirate infested seas can prevent this long-term knowledge transfer path and prevent the slow accumulation of knowledge that would otherwise occur. ## The Sixth Card: The Wheel The wheel of fortune shows a carriage wheel. Three beasts are depicted upon the wheel, the top one wears a crown and wields a rod of command, on the left is a beggar facing down in ragged apparel, while the right is a golden-haired beast ascending. Many millenia of stagnation, and the vague memory and vast ruins of countless past ages of glory will probably be the strongest factor in making the middle ages permanent. This cyclical view of the world, whereby all that is great will come down is in sharp contrast with the linear ascending mindset of a peoples who have seen the wonders of an industrial revolution. By contrast, the inhabitants of this stagnating world will have memories of empire upon empire upon empire, foundering like so many waves upon the rocky shores of time. The weight of history and the ruined splendor of the past's might, with the pessimistic, golden-age-past ancestor worship this is sure to engender, will be the strongest inhibitor of a scientific and industrial revolution to come. I dare not draw another card. [Answer] First. On the scale of "modern" humans 32,000 years is a really really long time. All of human recorded history only goes back at best 5000 years and lets face it that is pretty hazy history. 32,000 years counts for something like 1/6 of all of human history [(ballpark...depends on what dates you use)](http://en.wikipedia.org/wiki/Timeline_of_human_evolution). I would have trouble believing that anything could keep humanity from advancing for 32,000 years. Mainly meaning your world would be stretching my suspension of disbelief to the breaking point. I really think it is worth asking yourself if that kind of timeline is really necessary, what does it buy you? That said here are some things that you can use to slow down or even temporarily reverse societal and technological development. * Conflict. This is the most obvious detriment to advancement, but only in certain set ups. When you are talking about nation versus nation conflict in modern times, conflict can actually help things advance. I am referring to pre-industrial conflict where fighting is much more localized and generally on a smaller scale. If you live in a region where many tribes live and vie for power, the incessant fighting can mean people have no time for thinking beyond survival. * Limit resources. Advancement requires a certain amount of free time. Limit the availability or ease of getting basic items, wood, food, clothing etc etc etc and you have less time for people to create new things. We humans have to make sure our basic needs are taken care of first and if that takes up all our time... * Social taboo. This really won't work for your scenario in my opinion. If there is a desire for tech...it will happen especially in the timeline you mention. Think of the power the Catholic church had in Europe in Galileo's day. That didn't stop him from experimenting. * A small, isolated group of people. If you have a relatively small group, maybe there is a regular cull of some sort...maybe the flora and fauna are much more dangerous...or the religion requires human sacrifice, this idea is easier to stomach. But again 32,000 years is a really long time from a human development perspective. * Apocalypse. Big boom, massive flood, super virus, alien invaders...take your pick. This has the potential to send us back to the stone age...if we don't get wiped out completely. [Answer] ## Global lack of fuel There is some basis for a viewpoint that if our culture was destroyed, our own earth would be stuck on medieval technology afterwards due to lack of coal or other fossil fuels. You can't have an industrial revolution if muscle power or animal power is cheaper than industrial engines due to lack of cheap fuel. You can't really make alternative energy sources if you don't have the products and byproducts of an industrial revolution. You also can't really get most of industrial chemistry and medicine if you lack fossil hydrocarbons as a cheap mass source. Also, socially - you don't get capital investments if all the productivity is determined by people; instead of capital owners, creators, inventors and investors driving economic progress, all economy is determined by those who control the cheap laborers, i.e. feudal warlords instead of craftsmen and traders as historically. You don't really get a big science investment if most the products of science are impractical and uneconomical due to running only on whale oil and such. This means that in addition to medieval tech level, also the medieval social structure is much more stable, and conservatism is efficiently able to block progress. [Answer] It is absolutely natural for people to make technological improvements in any and every way that they can. 32,000 years is an absolutely absurd amount of time - the entirety of human cultural existence has only been 5,000-10,000 years, and in that time we've gone from not having language to having the internet. But if you're determined to use timescales far beyond anything we have experience with and have roughly 1,280 generations of people incapable of making improvements to technology and yet capable of making enough improvements to achieve a medieval lifestyle, here are some things that might work: 1 - a lack of fossil fuels - this one's pretty much absolutely necessary. 2 - near-constant earthquakes/volcanic activity - not only would this cause extreme stresses on the economy, but it would help to explain the first (any dead material would be more likely to be buried under volcanic ash) 3 - severe and unpredictable climate changes (i.e. ice ages that last 10 years followed by 20 years of drought and then a few years of flooding before another ice age and then a jump in temperatures up 40 degrees). 4 - Coordinated efforts from a significantly superior culture to annihilate any civilization that reaches too high. 5 - a world where the oxygen levels are significantly higher, so that things burn hotter and faster, and iron rusts nearly instantly (this, however, would mean that the world would have no really useful iron/bronze/steel etc. There would still be gold and silver, but they're useful as currencies - not as tools). But that 32,000 years is quite a sticking point - even with all of these issues I can't imagine the world staying stable for more than 100-200 years. Much like ours isn't. [Answer] Make life/trade so difficult that there isn't the opportunity to industrialize? Advanced machines need a big social base to build off. Enough food for everyone in the whole chain - from miners to metalworks to machinists to operators to retailers - and all the support infrastructure they need. If something keeps population centres small, or the entire population down, or makes it impractical to ship large quantities of goods, then even if the knowledge is there to make more advanced tech, the resources and the demand isn't there for it. Especially if you are happy to tolerate some of the technology being in existence, but restricted to a few, carefully crafted pieces etc then it works. Technology isn't just the science to know how, it's the infrastrcuture to deliver it, and the need/demand to deliver it. Factories, steam mills etc are of no use without big populations to sell goods to. Steam trains are only useful if you have lots of people and goods to move, and access to the vast amounts of steel and coal needed. etc. This all applies even more if people are struggling to keep the existing infrastrcuture going - irrigation, mills, trade by canal/river and horse etc - what opportunity is there to create something new, when just keeping life as good as it was last year is daily battle. Of course, people's ideas will have changed over that time. 32,000 years is about 4 times longer than recorded human history. That's time for an awful lot of philosophy, theology and even mathematics. [Answer] In addition to some good answers above, the Dark Ages, weren't that dark. A lot of things got invented and done in Medieval times. Off the top of my head, crop-rotation and horse collars - which added a lot of power available to people, as well as more people. Water-power trip-hammers and the like. Fragmentation is a cause of advancement, not a hindrance. For example China had both gunpowder and the printing press, but did next to nothing with them. Being in competition, Europeans developed those inventions into some pretty impressive technological and social changes. You want a single church, not various denominations. Any schisms will lead to competition, and competition will lead to progress. That said, I don't know that anyone has mentioned Europe's river system. Being able to get things to and from other places really helped out trade and the exchange of ideas and people. Instead you might put up barriers, but not mountains. Mountains tend to lead to free and unconquerable people, and you don't want much in the way of independence. Faster growing forests, with better roots might be what you need (too much wood, is a fuel source however). Clearing land was a huge problem, and keeping it cleared was an on-going battle. When manpower dropped after famine or plague, areas went out of cultivation. And, thus obviously, you'd also want climatic variations for some famine. But, you don't want to reduce your population too severely: part of the reason for guilds and locking development up tight was in order to ensure that everyone had a job - if there's a labor shortage, then labor-saving devices become worth doing. On the preventing markets scheme, you should kill the Jews. Well, the concept of allowing a minority to do what the majority could not do. You don't want anyone making loans / interest profit / capital investment. However, you're also going to have to prevent the Muslim models of lending as well. You want no financial innovations. Perhaps you could have the Church do all of the financing, and keep all the profits... but you're going to have problems with schisms and other issues. I'm not sure how that might work out, but it's something to think about. Good answers I liked: * Amish * No readily available hydrocarbon fuel supplies (Britain had coal, and had run out of accessible wood) * Prevent markets from developing and providing an incentive for trade * 32K years is a long time, and stretches disbelief. Why? [Answer] The impact of magic on such a society is being overlooked. Tight control of the church happened in medieval times, even with a priesthood that had no more access to miracles than anyone else. In a world with magic, such priests could literally smite the heretics with fire from heaven. For a comparison, consider the show Stargate SG-1 which introduced the Ori, a god-like race that held the population at a medieval level through the intervention of their priesthood, the Priors, who could use magic-like powers. Since you suggest that such powers do exist, you could put those powers in the hands of a priesthood dedicated to keeping the people pacifistic and under control. Since technology would represent a threat to that control, it is in their best interests to keep the people in check through the use of magic. As such, they would seek out any magic-capable individuals as youth and force them into the priesthood. Anyone who dissented is killed. Such an ingrained society would quickly drive even the best of tinkerers far underground. Who would dare to tinker with steam when your entire family gets wiped out as heretics by the priesthood the moment anyone finds out? The period of time you want this for is devastatingly long. That's 1000 generations without even the slightest advance in technology. We went from flint knives and bearskins to spacecraft and moon landings in less than one fourth of that time. Over so long a period of time, such a priesthood would become corrupt and be replaced from within rapidly, unless there was, ironically, someone high up in the church with the technology to suppress magic use in order to prevent coups from within. Even then, such a system would eventually fail. Concentrated power draws concentrated envy and ambition. Look at the procession of emperors in Rome, or even popes. Sometimes there were half a dozen in a single year through assassinations, power plays, or other infighting. A church/government with the power of life and death over every soul on the planet is going to be equally rampant with in-fighting. So, it's an idea, but not really enough for the time-scale you're talking about. Maybe if all the food-stuffs also produced a bliss-inducing hallucinogenic... [Answer] > > What religious rites could explicitly forbid things like steam engines > and gunpowder without the inventors of the religion having any > knowledge of these things. > > > The [Amish](http://en.wikipedia.org/wiki/Amish)/[Mennonite](http://en.wikipedia.org/wiki/Mennonite) model could work here. They aren't necessarily anti-technology, but they do very carefully weigh the impact of any new tech on their lifestyles and community. For [more conservative sects](http://en.wikipedia.org/wiki/Swartzentruber_Amish#Customs_and_technology) time saving inventions may be frowned on because they might make one lazy, and sloth is a sin. Being the inventor of such a device could make one proud, also a sin. Members who are known "sinners" may be [excommunicated](http://en.wikipedia.org/wiki/Excommunication) and/or [shunned](http://en.wikipedia.org/wiki/Shunning). One major advantage of going in this direction is that if the printing press or steam engine were invented, in your world, the general populace may see them, perhaps even give them a try, and then reject them on moral grounds. Conservative Amish communities have in many ways remained locked in the technology level of the late 1600's to early 1700's when their communities were founded. If these communities had started much earlier it may be reasonable to assume that they would have remained at a lower tech level. > > Medieval Europe was usually fragmented, and many technological > innovations began in China, where government was more stable. Europe > would have most likely developed these anyway, but not at the speed at > which it actually happened. How would political structure of the > continent-spanning empire effect the development of technology? What > level of political disunity could conceivable set technological > development back for many thousands of years? > > > While Amish communities are passive by nature there have been many schisms, the body of believers is divided and in many cases subdivided by religious doctrine. This religious division may lend it self well to having a single yet still divided empire. > > The crusades contributed to the Renaissance by killing many knights > and causing them to move to the holy land(causing their land to revert > to their descendants or the King) and introducing westerners to more > advanced Islamic sciences and Classical Greek ideals (e.g. democracy, > art and learning). What would have gone differently had the crusades > not happened? This directly effects my world because the entire known > world is owned by a single empire. > > > The Amish believe in what's often referred to as ["non-resistance"](http://amishamerica.com/why-dont-amish-serve-in-the-military/), they don't serve in the military, join police forces, or sue in court. So the crusades very likely wouldn't have happened. [Answer] For Catholicism and Eastern Orthodox, knowledge was bad. That is not the intend. If I remember correctly (feel free to correct me) , they considered that knowledge based on the divine was superior to what men could achieve with empiricism (and other means to gain knowledge), because men are not perfect, unlike God (God in Christianity). This all changed during the Renaissance were the reason of men came to be considered superior to religious reasoning. What greatly contributed to the slow apparent technological development is a characteristic, not exclusive but mostly found during the early middle ages. The destruction of the Eastern Roman Empire disrupted world trade with the orient. It still existed but was fragmented. Innovations spread slowly in these times. Another thing responsible for the slowdown was that the description also caused some resources to become unavailable to Europeans. The papyrus form Egypt was the only source of plant fibre used to produce paper. Europe lost access to that resource and they had to rely on using parchments that are made of animal skins. It's much more costly and books were very valuable but rare because of this. This slowed down the progress by quite a bit. By that time, Chinese knew how to make paper by using other fibres but this innovation took a long time before spreading to Europe. Some historians believe that the Carolingian empire could have started the Renaissances if it had survived longer because the prosperity and the reforms were really having a positive effect on the lives of the people. But the empire was divided, war followed and the north-men raided it. Medieval Europe was usually fragmented This can be a gift or a curse. During the Renaissance, it pushed the European states in a competition for innovation, exploration and commerce with other parts of the world. The competition forces the states to adapt or cease to exist when facing other competitors. China has been fragmented but for most of his history, it was considers as a unified entity. This allowed them to build great things but this lack of competition often meant that the state did not have much incentive to innovate. The crusades contributed to the Renaissance Yes, greatly. It allowed the Europeans to establish commercial relations with the Arabs, linking Europe with the rest of the world. Trade flourished, new products became available on the market, new ideas and invention came form the orient. the XII and XIII th century were two centuries of growth in all Europe. Other progresses were made during the Mongol invasions. They brought destruction in their path but also inventions form China such as gunpowder. Conclusion: Make people believe that the higher understandings can only be achieve by studying the holy book. All other explanations to explain the nature of things are biased and inferior. Also make sure that their only support for text is as costly as possible to slow down the spread of new innovations. Be sure to have no real competitor. Consider other states (if any) as inferior/barbaric/corrupted and cut all ties with them. Your civilization is superior and you have nothing to gain form them. They might try to rob you or to corrupt you with their strange ways. [Answer] I'm gonna go out on a limb here and say that all technology and advancement is invented and derived to help with a competitive need. If there are no competitive needs, then there would be no advancement. I think any society that does not experience shortfall would never need to advance. So, if you wanted a society to stay at a permanent medieval technology, then you would need to introduce something that completely and utterly removed the need to compete. For example, lets say there is a tree that grows extremely quickly without any effort that yield tremendous amounts of easily picked and stored nutritious fruit throughout all seasons. Additionally, lets say the bark of this tree sheds fibers that are easily turned into fabric and clothing. And the wood of the tree is a great building material with medieval tools. Then there would be no need for the medieval people to worry about food, clothing, or scarcity of home building materials. If the fruit of the tree also had a contraceptive affect, then you also wouldn't have to worry about competition from overpopulation, either. [Answer] I'm assuming you're writing a novel about an alternate world where magic exists, and you're looking for a plot device to explain why these people havn't changed much in terms of technology for 32,000 years. Things like distopian government or perpetual war and famine definately have a way of retarding and even regressing the progress of science and technology. That actually occurred in the centuries following the collapse of Roman Empire, at least in Europe. Also, necessity is the mother of invention, so if magic is prevalent in this hypothetical world, there would be no reason to invent things like light bulbs or advanced medicine. Another plot device would be that geographic isolation and language barriers prevent the free flow of information and trade. [Answer] I'm afraid having magic ruins everything. Anything that might stand in the way of progress, magic will be used to get around it - speeding up research, making otherwise impossible but required components, etc. Imagine a world where the Frankensteins and the Jules Verne characters could actually achieve their ambitions. Although it could be used negatively in your favour... Imagine a society of mages who value their power and recognise the threat to it that technology would pose - they could use their magic somehow to prevent progress. (e.g. early detection and prevention, ensuring that gunpowder simply doesn't work, etc.) [Answer] You will not be able to stop advance of civilization on our Earth. 32KY is a long time. But you can make advancement hard, and revert it few times, and add bad geography. * Start with a planet 80% covered with water. And most dry land is around poles. * Then ice age covers dry land. To survive, civilization has to retreat to few volcanic islands. They can grow plants, but cannot mine metals (there aren't any). Few metal tools were used up. Back to stone age, top tech is obsidian knife. * Without quality tools, settlers cannot build ships - it will take then few centuries to learn navigation and master back stone tools and build ships from local materials. * But even then, former dry land is covered by glaciers, and few protected areas are available to land on former continent to mine for more metal. Such expeditions would be extremely risky. Ice age can last long time (100KY) - interglacials are shorter (few tens of KY max). * Add strong religious tabu requiring plenty of human sacrifices, like Hawaii had. So life in tropical paradise islands will be easy, and getting out to get better tools will be hard. With only local enemies having exactly the weapons you have, there is no need to innovate. Your civilization could be stuck for a long time. 100KY if you are out of luck, until continents will become more hospitable to human habitation. Yes, you will have Inuits surviving on top of glaciers - but barely, and with little chance to advance your civilization. [Answer] As has been pointed out already, 32,000 years is an inconceivably long time to lack progress. Positing harsh conditions (war, famine, plague, etc.) is not enough; necessity is the mother of invention, and war in particular has historically been one of the great drivers of innovation throughout human history. WWII alone gave us great advances in aviation, automobiles, medicine, cryptography, plastics, and nutrition, not to mention the invention of radar, the computer, and nuclear power. No, to be stuck for that long, someone has to be actively working to suppress progress, such as [an all-powerful wizard king who fears the rise of new technologies that could challenge his dominance, particularly weapons,](http://brandonsanderson.com/books/mistborn/) or [powerful dragons who fear the rise of technological weapons that would give common people a much easier way to slay them,](http://www.paultwister.com) or [psychically gifted "gods" keeping technology in stasis so that the common people cannot develop ways to rise up and challenge them,](http://rads.stackoverflow.com/amzn/click/0060567236) or... well, you get the point. [Answer] First, a few pointers do science fiction literature: * The General and spin-offs, Stirling and Drake. The protagonists of these novels are trying to introduce progress after the breakdown of interstellar civilization with the help of ancient AIs. The respective worlds are kept in stasis by circumstances from soil degradation to social factors. * Heirs of Empire by Weber. The protagonists are shipwrecked on a world where an anti-tech church and an AI keep technology down. * Safehold series by Weber. Similar to Heirs, but much longer/more complicated and with a more detailed religious war angle. The long series isn't finished yet IIRC. * GURPS Fantasy (3rd edition) and GURPS Banestorm (4th edition). A setting for a pen-paper-and-dice roleplaying game where a conspiracy of mages keeps gunpowder down. With those ideas in mind, I think magic is the key: * Make sure that magic does not function on scientific principles. Research in magic does not translate into conventional science. * Make sure that magic is superior to primitive technology. Who will invent a bombard to batter down castle walls if a magic spell is so much more effective? But without a primitive bombard, no modern artillery. Who invents germ theory if healing spells usually work? * Make magic plentiful enough that nobody is tempted to look for a technical solution just because there is no mage available. * Give the mages a stake in keeping technology down. Perhaps mages get privileges due to their power, that would be put into question if every mundane could get the same effect with technology. [Answer] Since this is fantasy based, i will instantly jump on the magic-tech paradox given in most steam punk worlds (Almost every single except Full Metal-Fantasy). Magic getting close to technology will for some reason make the technology miss function or simply not working. When trying to develop gunpowder and it misfire or simply not work, the inventor will not work. So even if the inventor have found something that would work in a mana empty area, it would not work in a "normal" part of the world where the mana is existent and maybe abundant. If tech does not work. It will not advance. [Answer] I actually think the OP answered their own question: magic. Magic is so phenomenally convenient that the normative struggle leading to technological advancement ceases to exist. Actually, take Harry Potter as av example: these wizards are living in the 21st century but still reside in castles built nearly a millennia ago? They're confused and fascinated by cars, and some of them admire muggle ingenuity because it never occurred to then to develop computers, telephone, etc. It's entirely unnecessary when magic solves problems for you to search for alternate solutions. The other end of it is this: magic means either relative equality (everyone gets by on it - Harry Potter) or severe INequality (everyone provided for by powerful wizard lords - wizard of Oz.) In the latter case, the distribution of power means that peons may revolt against their wizard master, but overthrowing him would just invite another powerful wizard to step into his stead. War between the wizards would keep enough upheaval in place to prevent the sustained economic growth that would push technological innovation. True, war lead to some crazy technology, but it was the lull between wars that allowed those advances to be adapted to societies needs. [Answer] Maybe do something similar to the explanation given in the world of Dragonlance. In that world, the Kender race was constantly tinkering with things and either causing all sorts of problems immediately or ending up with overly-complicated Rube Goldberg-esque creations that also had a tendency of killing the users and anyone else within the 'kill zone'. This persuaded the other races to just stick with what they had. ]
[Question] [ I'm currently inventing a culture based on strength and power. They believe there's a fire in everybody that gives them life and power. They glorify warriors and strength. The culture lives in an medieval setting, and there is something like fire magic. Now I need an execution method as punishment for crime. I thought it should be something that shows in public that the person has lost its strength and honor. I don't think a simple beheading would work, for example. Burning dead bodies on a pyre (they believe in rebirth like a phoenix) is the usual funeral, so that wouldn't be fitting either. Do any of you have an idea for a fitting execution method? [Answer] How about drowning? Water is often seen as the opposite of fire, so this could even culturally be seen as killing someone by extinguishing their inner fire, rather than though asphyxiation. Similarly, if sea monsters of some sort are seen as the physical embodiment of water, feeding a person to them could be another possibility. [Answer] Because this is all tied to religious/magical significance the way I would probably approach this is to define more fully what is an honourable burial and reverse its symbolism. The first thing that springs to my mind is Ursula Le Guin's 2nd Earthsea book "The Tombs of Atuan". If you haven't already read it (& depending on how much time you want to spend) this is a truly excellent depiction of the worship of a dark power of the earth that's stifling and oppressive. I can imagine the culture you sketched decreeing a dishonourable execution to involve being buried alive in an imprisoning sarcophagus, wrapped with winding sheets of lead (i.e. totally immobilised) to emphasise total powerlessness. The eyes are left uncovered to add to the terror. Inscribed on the lead are hieroglyphs reciting: - spells of impotence to nullify the victims magical power - wards to prevent their rescue or location by magical means (i.e. from allies) - passages from religious texts depicting the tortures that await them in the afterlife - a list of their transgressions - the curse falling on any who recite their name or deeds in the world of the living. Maybe they could then be put on a funeral barge and floated down a subterranean river (i.e. a real-world River Styx) with carved stone banks. Hideous carrion-eating monsters and ghouls could inhabit the depths of this river. In opposition to this, honourable burial uses motifs of raptors (phoenixes, or giant vultures or "sun birds" who carry souls of the dead to the sun), and the metals gold, bronze and copper (the metal of the sun and light and fire). This lets you use cool metal death masks and pectorals and armbands and stuff. After cremation, the honourable dead have a life-sized clay or ceramic double of their body (i.e. baked in a kiln - more fire symbolism about passage form life to death) that is then buried on a seat / thrones in a tomb-niches in the side of of a pyramid. The niche faces outward with a slit for their eyes so they can watch out over / guard the lands of the living. The most honourable spots are that get the most sun. Each face (N,S,E,W) has its own mystical significance. Rulers are buried at the apex of the pyramid, then nobles or great heroes, and so on down to the deserving poor on the lowest level. Criminals are below the earth. So death is a handy tool for reinforcing the social order. This would work best for a culture that was: - very hierarchical & ritualistic - very focussed on the past & on your place in the afterlife - a place where the living are constantly reminded of, and in the presence of, their dead ancestors. [Answer] Dunk 'em in a frozen lake! That'd 'sap' their inner fire. Being suffocated and having your heat sapped is strong symbolistic way to demonstrate the weakness of their internal 'flame', especially in a world where death is celebrated by burning bodies [Answer] Being buried alive would also work, since [soil can be used to put out a fire](http://www.firescienceschools.org/blog/2010/10-things-you-can-use-to-put-out-fires/) by restricting the flow of oxygen. [Answer] While drowning is a great (and perhaps obvious) answer. There are some other subtle options: * Exile - Cheap, easy, and no need to keep a bunch of water around. Send the person out into the wilds and see if their strength matches up with nature. This also gives them the (fairly unrealistic) opportunity to overcome the exile, which may be politically or socially more palatable than outright execution. * Starvation - Nothing quite saps strength (and power) like it. Such a death could also seen as dishonorable since the person could not even have the basic power to subsist (or commit suicide). And seeing someone die like that would be a powerful reminder to others. Bonus points for using those middle ages iron cages for all to see. * Colosseum - Similar to exile, the prisoner gets a chance to win their freedom against a bunch of lions (or similar). Good fun for bloodthirsty populace, and if they don't win, they must not have been that strong/powerful/favored by the Gods. Dying to a bunch of lions though might be too honorable than just failing to survive on one's own. [Answer] This is a little brutal: use wet cloth to block the nostrils and mouth of the guilty. The cloth need to be wet so as to more completely block air flow. Lack of air certainly extinguishes fire. Using objects(cloths here) also feels more abusive and terrifying, while it will also be easier to publicly demonstrate execution on stages so as to threaten the people not to commit any crime. The executioner will use any convenient method to keep the wet cloth blocked inside the guilty's nostrils and mouths, be it by forcing the cloth in with bare hands or by using some otherworldly instruments of torture. Needless to say, the guilty will certainly be bound onto columns/pillars with their appendages fully constrained while being executed. [Answer] I suggest [waterboarding](http://en.wikipedia.org/wiki/Waterboarding). Even worse than just plain drowning. From the [Wikipedia page](http://en.wikipedia.org/wiki/Waterboarding): > > which water is poured over a cloth covering the face and breathing passages of an immobilized captive, causing the individual to experience the sensation of drowning. Waterboarding can cause extreme pain, dry drowning, damage to lungs, brain damage from oxygen deprivation, other physical injuries including broken bones due to struggling against restraints, lasting psychological damage, and death. > > > [...] > > > In the most common method of waterboarding, the captive's face is covered with cloth or some other thin material, and the subject is immobilized on his/her back at an incline of 10 to 20 degrees. Torturers pour water onto the face over the breathing passages, causing an almost immediate gag reflex and creating the sensation for the captive that he is drowning. Vomitus travels up the esophagus, which can then be inhaled (mostly into the right lung due to its more direct pathway). Victims of waterboarding are at extreme risk of sudden death due to the aspiration of vomitus." > > > This is a horrific method of execution, but I believe that's what you were looking for. Waterboarding, if not stopped, is such an extremely humiliating execution, where the victim will drown in his own (inhaled) vomit. [Answer] The execution chamber is a small glass-walled cage. The condemned is placed within the chamber. Smaller sections (also airtight from the outside, but sharing the air of the main chamber. Lit candles are placed in the smaller sections and the doors are closed. The candles rapidly use up the oxygen, dim, and go out. As the flames die, the condemned is seen to desperately thrash around and then collapse. The guttering of the flame symbolizes the guttering of his soul. ]
[Question] [ I am trying to find a gas that would be used as a weapon, which could also be made by someone in a medieval setting. The gas doesn’t have to be explicitly deadly, but anything that would incapacitate the enemy (knocking out, blinding, causing extreme sickness, etc) while being mass produced at a military scale would work. I have access to very skilled craftsmen who could make almost any tools needed for chemistry. The gas needs to linger long enough to take effect, and needs to take effect before the enemy is able to realize what is going on and leaves the area. I am not sure if there are even gasses like this that could be made without modern techniques, but if there are I would appreciate the info. Edit: These would need to be usable on the battlefield, not just in enclosed spaces or pre prepared ambushes/sieges. They could be used be stored in barrels which are opened (such as how it was used early during WW1) or launched (similar to artillery) [Answer] Pre-medieval chemical warfare has an extensive and ignoble history. Since this question is less worldbuilding, and in fact, answerable through history, I recommend reading about the [history of chemical warfare](https://en.wikipedia.org/wiki/History_of_chemical_warfare#Ancient_and_medieval_times). Your main conduit for creating heavier-than-air toxins is fire, which makes smoke. Despite being heavier than air, smoke rises because of the heat, but it has still been used in warfare, especially in Ancient China. Regular wood is a good starting point: poison sumac, castor oil, and fig trees all produce very nasty smoke I don't recommend inhaling. Moving up from there, burning arsenic produces toxic arsenic fumes. Sulfur, bitumen, and other naturally occurring petrochemicals all produce pretty foul smoke. [Answer] CO2 In laboratories and high-school classrooms animals occasionally need to be put to sleep for a short period for examination and other purposes. One of the things used is the gas CO2 or carbon dioxide. In the right circumstances this can be used on people. If your enemy enters a natural dip or something like a moat, cellar or dungeon, then the deployment of the gas can be effective as it's heavier than air. The gas itself can be produced by mixing quantities of easily available materials - chalk or lime with vinegar. These would need to be made available in fairly large quantities, the liquid being tipped onto the solid mass within a great pit, the maw of which spills onto the area that you'd want affected. Wind permitting, this should provide anaesthesia for a few minutes, death if longer. A cellar, or dungeon can have a casement opened by pulley to flush the asphyxiant out. It would then be safe to enter. [Answer] ## Chlorine Gas While this was not widely weaponized until WWI, it can be made using medieval technology. There are many ways to make Chlorine Gas, but the earliest recorded method was probably Aqua regia: a mixture of nitric acid and hydrochloric acid invented in the 13th century that alchemists used to dissolve noble metals like Gold and Platinum. However, Aqua regia is very unstable and releases a constant emission of Chlorine Gas. Although the full dangers of Chlorine Gas were not documented until the 1600s, Chlorine Gas is very noxious and its effects would have certainly been obvious to the alchemists who worked with it in the 1200s. So, while not historically weaponized in the medieval period, if a king ever bothered to ask an alchemist about weaponizing gases, this would have been an obvious choice. [Answer] Rather than CO2 a gas moat or asphyxiating pit trap would be better realised by SF6. [Sulphur hexafluoride](https://en.wikipedia.org/wiki/Sulfur_hexafluoride) is far denser, meaning it hangs around far longer, and, like CO2 is odourless and colourless. I suggest you could stretch late-medieval alchemy to get to it. You could possibly even pour it down a hillside into an enemy encampment in a valley. Unlike CO2, an increase in SF6 in the body isn't physiologically detectable. The urge to breathe when you hold your breath isn't due to lack of oxygen, but excess of CO2. This means that when it's used industrially e.g. (as an electrically insulating gas), real precautions have to be taken to vent, or perhaps I should say drain any leakage. The victim would pass out before realising anything was wrong, akin to [shallow water blackout](https://en.wikipedia.org/wiki/Freediving_blackout#Shallow_water_blackout). Once they'd collapsed, lying on the ground the concentration would be still higher than standing. Anyone going to rescue the victim would exert themselves and breath deeply. The mild anaesthetic effect would only add to the hazards. Potential contaminants in the manufacturing process and form environmental degradation are useful too: * [S2F10](https://en.wikipedia.org/wiki/Disulfur_decafluoride), which is toxic to the point that it's been considered for chemical warfare. This is liquid at room temperature but will have a significant vapour pressure; its odour is like burnt matches, so would probably go unnoticed on a battlefield. * [SF4](https://en.wikipedia.org/wiki/Sulfur_tetrafluoride) is a toxic and corrosive gas with a similar density to CO2 Sulphur has been known since antiquity, so the limit to production is fluorine. The earliest steps in [fluorine chemistry](https://en.wikipedia.org/wiki/Fluorine#Early_discoveries) go back to 1529, the very end of the middle ages, with possible 15th century alchemical mentions. Isolation took longer, partly because fluorine and in particular HF (hydrofluoric acid) killed people researching it. Compressing it to store it would be tricky but [not impossible](https://worldbuilding.stackexchange.com/a/188740/6348) (old answer of mine) [Answer] [Iron carbonyl](https://en.wikipedia.org/wiki/Iron_pentacarbonyl#Toxicity_and_hazards)? You get it by passing carbon monoxide over sufficiently finely divided iron metal. The carbon monoxide is only weakly attached, so inhaling it gives you carbon monoxide and free iron atoms in your lungs. It's also explosive in the right concentrations. It's (obviously) much heavier than air. If you can plausibly get nickel (not available pure until the 18th century on Earth, but there are ancient coins with 20% nickel in copper alloy) then [nickel carbonyl](https://en.wikipedia.org/wiki/Nickel_tetracarbonyl) is substantially nastier along the same lines. Its LC50 for a 30 minute exposure is about 3 parts per million, according to Wikipedia ]
[Question] [ Mothership to space vehicle EU W2775LV be like "pay taxes!" Space vehicle EU W2775LV be like "no!" And flies away in the distance. On earth we are kind of stuck living with one another, no matter where you go you still find people...even in the freakin' poles. Therefore it is vital for someone to make rules to protect the people. But, in space...who's gonna catch you? Who's gonna find you? Who's gonna care about you? Space is filled with rich planets and asteroids, what else could they want from you? Can't they build their own farms? Saturn alone is surrounded with asteroids and Jupiter has dozens of moons, you can take the solar system, I don't care, leave me alone! So I was wondering, is there even a reason to ever build a government in space? Laws can't be enforced because space travel is too slow, and space pirates can't really exist because space travel is too slow, and traders can't really exist because space travel is too slow. And unlike cars, spaceships can produce their own energy, without ever needing to stop and refill, a space chase never ends. Ands lets assume one really wanted to build something like a space empire, what would stop people from saying no and raising up their middle finger in protest? The roman legions took months, years even to invade, in space things go even slower. You want me to join your empire or you will invade my planet!? Hahaha! My bloodline will be already dead by the time you arrive! In short, in what situation would space governments make sense? Space = universe Ship travel = propulsion for limited times, unlimited solar sailing. [Answer] Yes, it makes sense for several reasons: * trade Even if each settlement and ship are fully self-sufficient trade between them will eventually be established. The only exception is when distances are so huge that trade is absolutely impossible. Please note, trade does not have to involve material goods. It is much easier to develop and protect trade when there is some sort of government in place. Trade flourishes only when merchants are guaranteed relatively stable and safe environments. Governments (official or unofficial) are one of the best ways to provide these guarantees. * big projects Governments are the only ones that can manage big projects, be they building or social projects. 'Government' here means an entity that has governing authority and is capable of enforcing this authority. * local governing Space-faring civilisations require a certain population size, density, specific technological level, and resources. All of these things must be maintained above a minimum threshold to allow space flight. Population density and size requirements can be circumvented if the technological level is very high, especially in the areas of robotisation and automatisation: Robots fully replace people when it comes to maintaining space flight infrastructure. Big groups of people (assuming that they are similar to modern humans) need governments to be sufficiently efficient to curb antisocial tendencies and maintain cultural and technological continuity. A big central government that governs over all human settlements will have only a symbolic value. Without FTL travel and communication no central government can extend and enforce its authority in a meaningful and permanent way. If news takes months and/or years to get to headquarters, effective governing is impossible. Most decisions must be made locally. The symbolic value of central government, however, can be very high and important. Symbols have power of their own. They can unite people and prevent them from fighting each other. They can give a sense of belonging and a sense of purpose. These are very important for humans and human societies. [Answer] ## It Will ... Eventually Space as of now, 2021, is pretty much a lawless place. We might think of it as the period before the "Wild West" era of American history. Think of the Moon landings as Leif Eriksson landing in Canada. Think of the various probes from Voyager right on up to the most recent Chinese rover on Mars as De Soto and Lewis & Clarke. Think of Skylab and Mir as Roanoke Colony -- short lived and later disappeared. Think of the ISS as St. Augustine -- the first long term colony. So far Space has only seen a few tenuous attempts at exploration and pseudo-colonisation. Sure, the crew of the ISS could declare themselves independent. But when the proverbial toilet paper runs out and Earth says "okay, you want to be independent? Make your own damn toiled paper!" it won't be more than about two hours and the Glorious Revolution will come to a constipated end. As of now, space government is neither needed nor warranted. But soon... You speak of rich asteroids and planets, and to be sure those are out there. Maybe in a hundred years there will be mining operations in the asteroid belt. There may be colonies and resorts on Mars and the Moon. But none of those places will be truly self sufficient. They'll be like mining towns in the Old West. Set up for one purpose -- to extract a resource and get it back to Earth. Of course it won't make much sense yet for some kind of space government to be formed. These colonies will be owned by Earth companies and those will be governed by national laws on Earth. If someone gets killed out on Mars, it's possible that evidence will be gathered locally, the person will be tried from Earth and will be punished on Mars. More than likely, some kind of local tribunal will do the best they can with the evidence and testimony available. Word of the killing may never get back to Earth. This will be the situation until there are enough people and sufficient settlements to warrant some kind of military or police presence in the colonies. In the Future... As the colonies increase in size and complexity, the need for local governance will increase. Chances are good that these colonies will govern themselves on the local & state model we have in western Earth countries. You'll have local elections for mayor or governor; you'll participate in national elections for your home state's legislators and for president. Until you can terraform a planet, and thus make its environment truly self-sustaining, there will always be a need for what only Earth can provide. All colonies, especially as they get bigger, will still rely on heavy manufacturing and raw (organic) materials that can't be found or made on site. Only then will a space government be truly practical. Think of terraforming Venus or Mars as the time in history when America no longer needed England for its manufactured goods and in fact could sustain itself and be considered a net producer rather than a net consumer. Once large groups of people are born, live and die on another world, when those worlds become their home -- that is when some kind of space government will be needed. Basically when the "Wild West" grows up enough to support its own manufacturing plants, its own towns and universities and churches and school systems and grocery stores and so forth. That's when humanity will need to roll out the plans for a solar system government the seeds of which will have been planted in the 21st century. It may be hundreds or even thousands of years from now. It may be never. A lot will depend on what is really and truly possible with the science and technology. If it turns out that there is absolutely no hope for rapid interstellar travel, then humanity will simply be limited to the Solar System and just barely be able to reach the nearest stars. If the likely planets of our own system can not ever be terraformed, then human existence on other planets will always be at grave risk of extinction. There will simply be no need for those colonies to be truly self-governing and sovereign states. [Answer] Mothership (full of fuel and supplies close to the transport’s destination) to space vehicle EU W2775LV be like "pay taxes!" Space vehicle EU W2775LV (near its destination, needing to slow down (not speed up) to enter orbit, almost out of fuel for maneuvers, and running low on other resources) : yes, please There’s a narrow range of velocities to reach an orbital target (11 km/s for an Earth-sized body). Lighter-weight bodies (space stations for example) require more low-speed maneuvers. Governments usually sit on the places where you want to be: that port where you want to come to zero velocity, open up your cargo doors, and put your goods in the hands of a buyer. They can offer services, but at their most parasitic, can simply take advantage of the ability to easily concentrate armed force where a wannabe Space Ace is weakest - in the hangar with bingo fuel holding the keys to the gas truck. They can also provide helpful services: wholesalers to be responsible for paying for your goods, regardless of whether or not synthetic Peonies have wiped out the worth of your cargo hold of seed. Harbor services to manage loading and unloading, service and repair, crew shuttle, as well as payment, so that all you have to do is slow down. [Answer] We have an analogous situation with the internet. Which is to say, it is possible to anonymize and encrypt your traffic with several hops through VPNs to make you unreachable physically by people you are communicating with, creating pockets of ungovernable space. We see ransomware attacks on the news with official government responses along the lines of "consider paying the ransom" even to companies vital to the nation's infrastructure. What we learn from this that would require some standardization and curating - which is a responsibility typically given to governments - is, the communication layer still has to be built out and maintained. Even if you don't have faster than light communication, if you're sending messages back and forth between Earth and Titan or Ganymede, those infrared lasers at the base station need to be reliably sending and receiving messages, on a bandwidth that is recognized, using a standard that does not change over long periods of time. This is especially true if you are communicating over light years worth of distance; your communication standard may have to be the same today as it was centuries ago just to communicate with a ship near Alpha Centauri. Now a standard, maintained equipment, and an incremental update framework does not take a government per-se. But none of this actually benefits anyone at the base station, especially if the ships being communicated with are very far away from the base station and are not expected to ever send resources back. So this definitely falls under the category of utility. While there are several open source efforts in our internet analogy to keep these services up and running, it can easily be argued that these efforts take on all the aspects of a government out of necessity. It's just that instead of using threat of violence to ensure compliance... the technology or service simply doesn't work at all if you don't comply. And this gives any existing governments tools to enforce laws in space. Even if you cannot physically stop a pirate trillions of miles away, any better than we can physically stop a ransomware attack today, you can restrict the services you are providing to known, accredited parties. If someone is able to report to base station before their ship was attacked, that ship can no longer be used to access not only any Earth-origin services, but any services in the solar system. You've effectively forced these people to rely on "dark" services, and denied them any safe haven save for a few pirate enclaves. The situation would be very similar to being a pirate about 400 years ago; you'll never be able to safely do business in Europe or the colonies. You may be able to take over a small island (or in this case asteroid) and establish yourself as a governor to guarantee resources for your pirate fleet, and other pirate fleets that have managed to do this are going to have a lot of pull over the available safe havens, so even if you're restricting yourself to "free cities", you're still interacting with governments. Many of the most famous pirates had constitutions, codes of laws, and other trappings of governments. [Answer] > > a space chase never ends > > > That's not entirely correct, a ship presumably goes from somewhere to somewhere else. If it doesn't, then it truly doesn't matter what they do, they're effectively their own sovereign nation outside of anybody's effective control. It's when a ship shows up to a spaceport with a dead body, a cargohold full of drugs, or outstanding taxes to pay that you need to be able to bring down the hammer. Now, the answer to the question depends on how you define "government". In your context, with only limited travel between generally isolated colonies what you need is a supranational organisation with some legislative and judicial power, and executive powers to enforce laws can be deferred to its member states. Space United Nations An organisation that allows members to draw up treaties and gives them authority to enforce them. You don't particularly need space police if you have treaties that empower members to prosecute crimes reported in space at the port of arrival, wherever that is; to arrest people on behalf of other members; and to generally enforce their own laws (or the supranational law) on any ship that enters their jurisdiction. This would be the organisation that adjudicates disputes between members, accordding to rules everybody has agreed to. It would make up trade and immigration regulation to benefit all its members. And like international law, it would all be largely voluntary and enforced in effect by how much trade you want to do with your neighbours. [Answer] Government makes sense only to the extent that control can be maintained. If your propulsion is such that only single-body colonies can be controlled that will be the extent of your government. If instead somehow your propulsion is extended such that entire solar systems can be reached in reasonable times then government will extend to fill that niche. And for larger bodies it may well occur that you get multiple governments (as we currently have on Earth). Remember, governments theorize that only they are allowed the legitimate use of organized force (some go further and posit that not even disorganized force is allowed. But if there is no organized force present then disorganized force is pretty much bound to follow. So decide upon your propulsion and the level of government is answered. Note that Earth governments currently play along because force can be deployed anywhere on the planet in reasonable time, what we've sent into space is so minuscule in comparison that it might as well not count. If/when someone actually creates a space colony/habitat that is actually fully self-sufficient those Earth governments are going to have a much harder time exercising any sort of authority (note that right now we are incredibly far from that fully self-sufficient criteria). [Answer] For a government to exist, it needs to have power over people, or to provide them with useful services (or both). If the people on the spaceship can't be caught, they might still want to make use of government services, for the education of their children, or healthcare, or providing a safe place to trade / take holidays / hire crew. In order to enjoy these benefits, they would have to pay their taxes. [Answer] Sure a space government can make sense IF they control the means of production for creating critical systems and materials. Sure space vehicle EU W2775LV can take off and avoid taxation, until it needs fuel that is. It was carefully built to be dependent on outside manufacturing for that, so was the mothership for that matter. They also don't have the gear, or spare parts, for a full overhaul just enough for short tours of routine maintenance and a few expected emergent contingencies. If you can't take enough, functional, equipment with you to establish a living colony outside existing production and supply lines then you have to render unto Caesar. Functionality is an important constraint, if the firmware of your equipment is hardwired to crash without regular subscription updates then you can't even steal the complex techno-artifacts you need to go it alone, even if they aren't kept under physical lock and key. [Answer] > > Consequently, each State handles its issues with the laws that pertain to its jurisdiction, except monetary issues, such as the printing of money. Other examples of decentralized governments include the governments of Australia, Canada, Germany, and India. > > > As no one recalled about decentralized government examples, seems it needs a reminder. In some sense laws and rules can be considered as best working practices, sure it constantly evolving system and many of laws may be far from being good or at mature state. But other rules are. Development of laws takes time, development of procedures, testing all that take time and effort. Or let's look at software licenses GPL, MIT or creative work CC BY, etc. Once you need one, you will probably stick to some of those, instead of reinventing a wheel. Including for reasons they are recognized/familiar to other people and have some support. TOS's (terms of service) are usually custom made and those local governors force you to read meaningless walls of text which basically say one thing - we owe you nothing and you owe as much as possible. You agree without reading because it is the only way to access the service, and you expect that if they will oppress you as a user class, the user class can fight back no matter the content of that TOS. There are positive and less successful examples of that so as slavery societies of users(looking at you - windows apple). People of the right to repair act they fight apple madness for years now, and they grow in their strength. Idealistic anarchy guys way have wet dreams of not having any rules or anything, but pragmatic anarchy guys know that humans need some coherence to be able to combine their efforts to make things(including good ones) happen, which are not possible for a disorganized number of people. Combination of collective effort, our ability to do so - that actually is what allowed our ancestors to take a dominating position in the animal world. Some animals can do similar things, and thus being more successful in surviving, but we have no limits in the cooperation efforts, no limits by a number of participants, because we invent swarm rules, in some cases, some call them law systems and such. Our physical ability to cooperate, as individuals, is limited by and proportional to so-called [Dunbar's number](https://en.m.wikipedia.org/wiki/Dunbar%27s_number) but with rule systems, we easily overcome such limitations and it has a great effect on our abilities. An example of that is standardization in production, measuring systems, and units. Which by itself is a system of rules and practices. Adhering to with takes effort, time to learn, and such but it is beneficial to stick to some - for plenty of reasons, including because those rules make sense. There are all kinds of industrial standards. So any type of government - centralized, decentralized, private, swarm, hive mind, whatever - in the first place it is a system which allows combining individual efforts in a mighty force, way above just simple sum of those individual forces for purpose of individuals to ripe fruits of such large scale cooperation - fruits vary from just survivial as species to our day's technologies. So it those benefits which join us, which are attractive and which are the reason for different types of management to exist. Taxation(is theft), enforcing rules, etc - are not what makes governance happen. The benefits are, but the rest is just a payload the ship carries. Sure payload exists for different reasons, big topic, but they are secondary things. ## answering your q * in what situation would space governments make sense? Always * Does a space government make sense? Yes It is just not necessarily what you imagine, and does not necessarily work in a way you imagine. But that is a different q. If nothing else, at least look at how The Internet was built, also search for RFC. Take look at how DNS works and why it is possible to sell domain names. I mean look around. ps btw - language orthography grammar also is a form of government - and if you ask me it is quite oppressive, lol. [Answer] Sure (eventually) Mars runs itself and Venus runs itself, but what happens when Mars wants to trade with Venus? Sure ships can start moving goods between the planets but someone will come along complaining that those Venusian's are under cutting the local Mars built products. Thus people will demand that something should be done about it. The usual way then is import taxes, which needs some sort of government to enforce it (well people with big sticks to enforce it). Then the Venusian's get annoyed their good are being taxed, so they send their fleet. People start negotiating (but that needs some central person who can agree to terms on behalf of everyone else) and everything settles down when a trade deal gets struck. Import taxes are reduced and the chance of getting shot at goes down considerably. Then those pesky space pirates coming along to raid your space station/colony of all the good whiskey. So again something must be done about it. So you build your police forces up (which need a central body to pay for, train, and control). Pretty much any time a large enough group of people get together some sort of hierarchy (and eventually) government will form. Mostly for self-protection at first, but then to pay taxes (to pay for the self-protection), and to act as a central body when negotiating with other groups. [Answer] > > And unlike cars, spaceships can produce their own energy, without ever needing to stop and refill > > > Energy doesn't come from nowhere. Nuclear fuel decays and produces less energy over time. A fusion reactor requires stuff to fuse. Solar panels degrade over time, and produce less power the further you get away from the Sun (or whatever star you're orbiting). A reaction drive needs propellant to accelerate, and reactionless drives require fantastic amounts of energy. Eventually you will have to stop to refuel, whether that means extracting raw materials from an asteroid or hitting a space version of a truck stop, and that's when they getcha. Your ship will eventually need some kind of repair beyond your ability to do yourself, at which point you have to interact with other people. You will have to come to agreements on fair values for exchange of materials, labor, and time. Small enough communities can get away with barter systems, but if you're going to deal with any kind of currency, there's going to be a government involved. There likely will never be a system-wide central government for the reasons you describe, but any outpost or settlement with more than a couple of dozen people will form some kind of local government with their own local law enforcement. [Answer] Something similar already happened in the 16th to 18th centuries. At the time the reach of the authorities was limited by the technologies, but ships often travelled to the other side of the world. With no other authority around the captain of the ship had absolute power and with the wrong captain conditions for the crew could be harsh. That is why mutinies were severely punished, without the threat of death they would have happened very often. And it doesn't stop with mutinies, piracy was rife. So, in your setting refusal of an external authority might happen in spaceships with a small crew where people needing each other would avoid trampling over their mates. But in a spaceship with alarge crew eventually some people would start abusing the others, rejecting an external authority with the rules coming from it would not be in everyone interest. [Answer] Where is that fleeing ship going to get supplies? Food, water, fuel, medical, you name it. It needs to land or dock somewhere to get all that. Unless your universe is rife with pirate bases and other outcasts that don't obey the powers that be and are too hard for those powers to track down and destroy or make submit (in which case, are they really in power?) they'll have to go to a government controlled (in some way) facility at some point, probably sooner rather than later. And if you're thinking of having a single universe spanning government rather than numerous smaller regional ones (with supposedly no extradition treaties) that means falling into the hands of the space police and universal revenue service at that time. How long that's going to take will depend on the level of control the space police has of course. They can't be everywhere at the same time, obviously, so landing on a remote location on a backwater planet in an uncivilised galactic arm around a small orange yellow star may go unnoticed, extending their freedom until their ship needs repairs or refueling to an extent they can't postpone. But it will happen eventually. ]
[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/101447/edit). Closed 6 years ago. [Improve this question](/posts/101447/edit) With the exception of blood type O-, humans simply can't be given "any old blood type" without the potential of causing serious harm. I assume that in reality, a newly-dead body would still react negatively to an attempt to give the wrong blood type (which might be done in an attempt to resuscitate the body). Therefore, would death release Vampires from the blood type restriction, or would they also be restricted in what blood type they can consume? Please note that [this previous question](https://worldbuilding.stackexchange.com/questions/32500/would-different-types-of-blood-ab-o-have-different-nutrients-for-vampire) asked if there would be a nutritional difference. That is not what I'm asking (and I agree with the answer). Background Curiously, science doesn't completely understand how vampire bats metabolize blood. However, they do know that it involves using a [plasminogen activator](https://en.wikipedia.org/wiki/Plasminogen_activator) in their saliva (which we have in our blood to prevent coagulation). ([source](https://www.newscientist.com/article/dn15083-how-vampires-evolved-to-live-on-blood-alone/)). Beyond this, it appears that vampire bats metabolize blood in the same way all other foods are metabolized. *What do* they do with that blood, anyway?** OK, after having some fun reading up on the history of vampires in fiction, and not to invalidate existing answers, or to deny my deepest respect for the Marvel comic universe, I've decided to go with the (obviously obvious) belief that [Vampires have ichor](http://www.marveldirectory.com/groupsandteams/vampires.htm) in their veins. Therefore, blood is ingested only for nutrition and is not directly conveyed into the bloodstream. [Answer] Only if they aren't digesting it Blood types must be considered in a blood transfusion to avoid rejection by the recipient's immune system. However, if a vampire, or human for that matter, were to drink human blood the stomach acids and digestive enzymes would destroy all of the proteins involved in a blood type before they ever entered the blood stream. If your vampires consume blood in the same way a vampire bat does then they will not need to concern themselves with the blood type of their victims. [Answer] Vampire lore is a mess of contradictions and it makes sense to identify how a vampire 'works' in order to provide a more detailed answer to this question. For instance, the fact that they're (in a word) dead, cold and either immortal or extremely long lived indicates a very slow metabolism. On the other hand, super healing capabilities would indicate a very fast metabolism. In a [previous answer](https://worldbuilding.stackexchange.com/questions/99714/could-a-decreased-heartrate-thanks-to-better-hemoglobin-lead-to-an-increased-lif) I pointed out that excess oxidisation is actually likely to cause faster ageing than not; free radicals are the enemy to a prolonged life. So; in this answer I'm going to assume that; 1) Vampires do have incredibly slow metabolisms 2) Super healing is either a myth they promote or a result of excess handwavium in their systems. With that in mind, vampires would digest blood, meaning they break it down for nutrients, making the blood type irrelevant. The reason that they need blood (and blood only) is that the haemoglobin contains just enough oxygen to metabolise the nutrition in the blood, and no more. There's probably no other food type that contains sufficient oxygen to allow the food to be absorbed directly without additional O2 being supplied, which is why; 1) The blood has to be fresh to work (common vampire lore) 2) They bite their victims and intake blood through the mouth 3) Other foods appear as 'toxic' to them (they can't metabolise it) 4) They can survive on such small amounts of 'food' What all this means is that vampires don't breathe. When you stop and think about it, that actually makes sense. They're dead and they can survive in coffins or underground for extended periods. Some lore also has them able to survive underwater, but if you go to the Dracula book by Bram Stoker, they can't cross running water at all which would be another contradiction. Suffice it to say, that our vampires don't breathe so need oxygen in their food to metabolise it (hence fresh blood). If we disregard Bram Stoker again (who tells us vampires can survive daylight but with curtailed abilities) and go with the regular lore that vampires are destroyed by sunlight, this is also consistent. Low energy creatures such as vampires would find the relative heat of the day to be overpowering by comparison to their normal very low body temperatures. Assuming they're still warm blooded in nature (in this case meaning that they have to maintain a differential between the outside temp and their internally consistent body temp) then standing in daylight when their normal core temp is so low would be like us standing in the middle of a forest fire and trying to survive. They probably wouldn't burst into flame, but they would die of heat stress pretty quickly. With all this in mind, I'm going to say that if my understanding of vampire physiology is correct, blood type wouldn't matter to a vampire, but relative freshness would. That means that artificial blood, or even blood stored in a blood bank, would be useless to a vampire. Ideally, they'd want blood fresh from a living artery (going between the lungs and heart of a live animal) so as to be able to metabolise the blood through digestion-like processes that combine the oxidisation step in situ. [Answer] Reasonable perhaps but completely unnecessary. Let's forget all this modern twaddle about trying to justify the existence of vampires and possible biological mechanisms for how they function and manifest themselves. Steer clear of viral agents being responsible for vampirism. It's time to go to basics. Vampires are supernatural monsters pure and simple. They are undead. They're already dead. presumably then it is some supernatural force makes them mobile, active, and able to harm the living. The drinking blood business simply comes with territory. Like being allergic garlic, holy water, not reflecting in mirrors (now just try and explain that scientifically, you smart scientifically minded and obsessed kiddy-winkies), and being unable to bear the sight of the Cross. Plus having stakes driven through your heart. Supernatural forces always work their own perverse, irrational logic. Otherwise what would be the point of them being supernatural forces. Next thing they could be explained scientifically if they weren't. Presumably the fanging of victims and ingesting their blood might have something with vital spirits or forces, but that a hopelessly outmoded and discredited concept from old-fashioned, pre-modern bad science. Therefore, it could be perfectly in keeping with the operation of supernatural forces and powers. Let's face with vampires are not only dead, they're most definitely undead. This means there is absolutely no way that mixing blood types or being restricted to specific blood groups makes any sense at all. Why? because they're already dead. They can't be harmed by ingestion of the wrong blood (if that means anything in this context) which is one of the advantages of being dead. In conclusion, there is absolutely no reason why vampires, supernatural vampires that is, should be restricted in the blood groups of the blood they imbibe and ingest. They are above and beyond any normal physiological or biological functions [Answer] Having read the other answers on here, I've come up with an idea. Perhaps rather than only being able to drink only O- blood, your vampires can only drink one blood type at a time. This could be achieved by having a dedicated blood sac in the vampire's body, or if you're cool with the vampires not eating normal food, the stomach works too. Most blood types don't mix, and a few days worth of blood is ideally stored in the sac/stomach at any one time. This is going to make feeding difficult, as your vampire can't feed from a conflicting blood type without projectile vomiting afterwards. Now unless your vampires can smell, taste, or otherwise determine blood type without stealing their donor card, it's going to be a LOT safer to just simply drink O- blood as that can mix with any blood type with no issues. However, how do the vampires tell who is O- if that is the case? Perhaps they are the ones that are marked by other vampires as prime feeding targets, or maybe vampires would go to the trouble of stealing a list or cracking a database of O- donors! [Answer] Blood type is important only when mixing blood; the problem is parts of different immune systems getting into fights. If the vampires don't have their own blood anymore, or their immune system works significantly differently than ours there won't be a problem even if the victim's blood is directly transfered. Whatever mechanism vampirism uses to deal with a body's immune system in making a new vampire might plausibly work against blood from another body. A virus needs to be able to defeat the immune system, and magic obviously can handwave it away, if that's what you want. Blood typing wasn't discovered until long after traditional vampire stories were established. It would be a very risky un-life for non-AB typed vampires if every meal was gambling with a transfusion rejection. But that could explain why they might stick with a single victim and take interest in dungeons or [romance](https://skeptics.stackexchange.com/questions/40255/fewer-shared-immune-genes-in-a-couple-correlate-with-or-even-cause-more-female). [Answer] Vampire don't drink blood because they need it to survive, but because they are addicted to blood, the same way a human is addicted to heroin or other hard drug. But only the O- blood plainly works, the added elements in other blood type render the blood-drug either inefficient or this less efficient (if it fits your need it could allow the vampire to consume any type -even animal blood- as a succédané but it will always prefer the O- which is so much potent). Note: this idea com from the discussion between @a4android and @Tim B (This solve the "It drinks blood, why? This plainly didn't make sense") ]
[Question] [ Let us assume that about 10,000 years ago there was another human civilization, that was quite similar to humanity. Physically they are humans. The state of development of this civilization is quite close to ours - they had learned electricity, ships, cars, airplanes. But they were much stronger than us in nanotechnology and waste recycling, and they did all they could to keep the planet clean and unpolluted. For example, all their machinery decomposed into dust after few years without contact with humans, they used solar panels and not fossil fuel for getting energy and they tend to live in natural environment - without big cities and so on. But some natural disaster 10,000 years ago have wiped out this civilization from Earth (for example, a nuclear winter from an asteroid impact or a volcano), and the scattered remains of this civilization survived as prehistoric humans, which forgot nearly anything about their glory. So, the question is: how can the modern humans find the traces of existence of this civilization? What is the most possible and realistic way to prove, that this civilization existed? [Answer] One starting point would be to ask what objects have survived for 10000 years in reality? One possible survival would be artwork and jewelry. In particular I am thinking of artwork that was carved into durable materials like stone or bone or glass. Even just painting inside a cave can last 10000 years or more. Since these objects are not themselves "technological" regardless of the tools used to do the carving they would not have disintegrated like the technological artifacts the way you supposed. [Answer] Keep in mind that archaeology can learn as much by what is missing as by what is present. In the UK we have a stone-age village from thousands of years ago that has been recreated by analyzing the holes in the ground that the huts and their support posts made. These houses were made completely from wood but the evidence lay preserved in the ground until archeologists found it. It's unlikely that absolutely everything would be completely bio-degradable, and even if it was that process itself would leave evidence. As soon as you lay out things in organized ways those patterns become visible and are preserved in the ground for a surprising length of time. [Answer] They would leave the same artifacts humans would have, up to the point where they decided to only use biodegradable everything. I don't like this answer, but it fits. This question begs the question, I suppose, of how they got to such a level of technology. If they were always eco-mentalists, why? When you're struggling to survive against nature, privation, tyranny, genocide, etc, are you REALLY going to give a fig about your carbon footprint? So, understanding that some questions get asked without fully understanding the question behind the question, if your question is "how do I have an untraceable race of greenies," you have to explain not just how they advanced past the Stone Age without leaving lasting traces, but WHY. Sub-questions: "How can modern humans find the traces of existence of this civilization? What is the most possible and realistic way to prove, that this civilization existed?" The answer to these sub-questions is essentially the core answer above. Modern humans could find the traces of existence of this civilization in the same way modern humans find traces of the existence of other civilizations: By the parts that didn't degrade into "noise." The most possible and realistic way to prove that this civilization existed is the same way we prove that other civilizations existed. Keep in mind, religious proscriptions are about things people are liable to do. Few and far between are the explicit proscriptions against eating feces, because that avoidance is built into (essentially) everyone. Any proscription against pollution which is intended to include all artifacts (including trails, bones of the dead, the indentations which homes leave in the terrain versus the dirt that would build up around them etc) from before this proscription would be fighting against human nature. It would also require gargantuan, literally incredible effort. There would need to be a god-agency (which you have) not just making declarations and punishing, but also deeply involved depending on just how wide-ranging this proscription is. I have assumed complete and total erasure, since the question and sub-questions presume it will be extraordinarily difficult. For example, even if we ignore everything from before this culture gets all nano-techy, the fact that their machinery crumbles into dust does not mean it is untraceable. There will be, after all, a rather conspicuous arrangement of dust. That dust will be made up of whatever those nano-bots were--so if the manufacturing process reduces everything to carbon in order to make nanobots out of carbon nanotubes (or just "alters the atomic structure into MacGuffinite, which is ideal for nanobots"), you'll have a pile of carbon/MacGuffinite. Wind will not be sufficient everywhere to disperse this. If you've ever seen intelligence analysis of aerial recon, you'll see that very vague shapes can be determined to be specific objects by their arrangement, positioning, and other artifacts around them. Archaeology cranks this up to 11. OK, you can assume perfect cleanup protocols for the last nanobots... well, that's up to you, but then you're stuck with your core question of what I'm assuming is your plot hook. To this I re-state the first sentence: Leave some evidence of former eras for your modern humans to find--especially since removing that would require insane effort even for nanotechnology (aka scifi magic, no offence). Even removing evidence of former eras should leave evidence that something has been disturbed, which can lead to reviewing the arrangement of that something, questioning locals (if not on the planet in question, then perhaps others in "this sector"), analyzing flora/fauna patterns, etc. Not sure if there's an archaeology SE, but that's the road you seem to be headed towards if you want excruciating details. Read an article every so often from <http://www.archaeology.org/> and you may find some great ideas. [Answer] If everything was eaten away by nano-tech, I'd expect to find very few artifacts. You could likely see physical evidence. Mining, landscaping, old roads, things like that. The land wouldn't appear entirely untouched. Somewhere like New York City would have caved in, some mountain tunnels would remain, the panama canal would be an odd thing to come across. You may also find remnants of the nano-tech if it doesn't self destruct. [Answer] Just look at what modern day archaeology can find out from tiny remains of early humans. 10.000 years isn't that much actually, totally in reach of C14 dating for example. Around 10.000 years ago neanderthals died out. You mention a global disaster as the cause of breakdown. Disasters like that often provide the very best sites to preserve things for very long times. Examples: * Human footprints covered and preserved by volcanic ashes (<https://en.wikipedia.org/wiki/Laetoli>) 3.7 Million years old (!) So if those ancient humans had shoes, you could find a trace. * Oxygen isotope analysis of human teeth to determine the origin of someone. If some ancient person travelled huge distances according to this, it would be a hint. (<http://www.wessexarch.co.uk/projects/amesbury/tests/oxygen_isotope.html>) * Archaeobiological methods to detect large changes in the fauna, e.g. if the population is large you would find significant signs due to the need to grow food. For example you would have more plains to grow grain instead of the natural woodlands or you would have an unnaturally high amount of food crops. All of this is detectable via pollen analysis. * Even if you use nanotech, you need some amounts of raw materials. So if you extract those from natural minerals via nanotech, you would find spots where you would expect large amounts of metals due to the mineral composition but would find none. Adding all tiny traces could paint a good picture, just like the one we already get about neanderthals. [Answer] I think I'd like to answer your question in a slightly different way, by quoting Isaac Asimov: > > The most exciting phrase to hear in science, the one that heralds new > discoveries, is not 'Eureka!' but 'That's funny...' > > > Depending on the particular method of demise of the previous culture, how fast it strikes, what it strikes, etc, there are millions of answers to the technical question. Imagination is really the limit. Having a believable "proof" of a previous civilization is less in the technical detail and more in making it seem reasonable that the moment of discovery comes in the form of "That's kind of funny." [Answer] After tens of thousands of years, the programming of the nano tech may have become corrupt, so as modern human civilization arose, there would have been fairly obvious "no go" zones where the stuff was consuming forests, animals or mountain ranges, or spitting out fairly obvious waste products. Even if the waste was something like CO2, there would be unexplained and unexplainable hot spots where the nano tech was working. IF these lasted into modern times, then we would have a relatively easy time to isolate and understand what was happening. Even if these events had stopped and faded into ancient legends, there would still be clues for people to follow to investigate. If the nano tech itself had become extinct, there might still be deposits of unexplainable material layered in geological strata from that era. Instead of Iridium like we find in the K-T boundary, there might be sheets of graphine or fullerines, since much of the technology might well have been created by nano machines manipulating carbon (one of the more versatile elements, which could function as a structural material, electrical conductor or even storage medium, depending on how it was configured.) Finally, if this race was as advanced as you say, they may have gone into space. Orbiting satellites would have vanished long ago due to orbital decay, but probes and devices left on the Moon or deep space might last as long as a quarter billion years in recognizable form. The equivalent of the Eagle's landing stage and the footprints of these ancient astronauts will still be waiting on the Moon for someone to find. [Answer] The obvious answer is there would be a whole mess of recycling nanotech instruments springing into action to reclaim any waste. These would remain, presumably working on animal waste, and we would have noticed them working from early in our history. [Answer] The [Aboriginal Australians](https://en.wikipedia.org/wiki/History_of_Indigenous_Australians) are estimated to have been around down-under for around 40.000 years. So, this could give you a general guideline. ]
[Question] [ I have heard that in order to be domesticable, the animal has to satisfy the 4 Fs: * Friendly * Fecund * Feedable * Family-oriented Okay so let's narrow this down. All dinosaurs would fall under Fecund because a single dinosaur can lay up to 30 eggs at a time. Long maturity but lots of eggs. But even the biggest dinosaur eggs would not be much bigger than a basketball, otherwise, the dinosaur inside wouldn't be able to breathe. Feedable narrows things down further to herbivores, omnivores, and carnivores up to the size of Utahraptor. So these dinosaurs would be feedable: * Triceratops * Stegosaurus * Utahraptor(carnivore about the size of a human) * Eoraptor(small, possibly an omnivore) * Ornithomimus(omnivore) * etc. Family-oriented, that's hard to say but almost all herbivores would fall under family-oriented. Friendly, again, that's hard to say but I think all herbivores would fall under friendly, not so sure about the omnivores and smaller carnivores though. But what dinosaurs would fall under the 4 Fs and thus be domesticable? [Answer] Bird are part of the dinosaur clade, and hence are dinosaurs themselves... and chickens are a good candidate for a domesticated dinosaurs because it is well, domesticated. Chickens are friendly, fecund, feedable and family-oriented too, so perfect candidate. Chickens are friendly unless you poke it beyond return ( they usually try to avoid you then) Chickens are fecund because they lay a lot of eggs Chickens are feedable as you can feed them seeds Chickens are family-oriented as you can raise it with your family. [Answer] ## There is no way to answer this. Domesticability is primarily based on criteria that do not leave fossil evidence. Three of the biggest factors are complete unknowns. The animal needs to engage in hierarchical social behavior (or be semi-social and group tolerant like cats) , they need a calm demeanor, and they need breed easily. All three of these are unknowns for dinosaurs. You can't even make an educated guess based on relatives, horses and zebra are extremely closely related and yet one was easily domesticated and the other has not been to this day. You are correct that dinosaurs are more fecunded than mammal so you have that working for you. If you want to have domesticated dinosaurs your story you can and no one can say its impossible. There is however a few that can be eliminated; predators larger than humans are out because they would be far too dangerous and anything that has a generation time longer than the human one is out because it takes to long to get any use out of them but other than that you can do as you please. Keep in mind how you define their behavior will have an impact, if you define dinosaur X in your story as temperamental and solitary then you should not have them domesticated as well. [Answer] I think the best answer is really just to assume, at first, that all dinosaurs can be domesticated, and then apply an elimination process and work with that, as there's no way of knowing directly. you can eliminate: * Any carnivore larger than a human * Any dinosaur that lived in isolation * And dinosaur that has a longer life span than a human Also, consider reasoning. We domesticated dogs to hunt with, cats to catch our rats, horses to labour and to ride, cows and sheep etc. for food. Only herbivores can be bred for food, as for carnivores, it would be more efficient to just eat whatever you're feeding them (2nd law of thermodynamics says this); and only herbivores can be ridden, as you can only ride a species that's larger than you. Only carnivores can be used to hunt with or for pest-control, and as hunting goes, only relatively intelligent pack animals (I think a raptor would fit this category) Also bear in mind that since dinosaurs had hollow bones, ridding them would be a problem as they'd probably struggle to bear the weight of anything that didn't have hollow bones. Edit: For clarification: to be feedable, a species has to reproduce quickly, and has to eat abundant vegetation. To be ridable, a dinosaur would have to be significantly larger than a human, and be intelligent enough to respond to commands Only pack animals can be used for hunting, as others cannot cooperate. [Answer] 1. This is a slightly different take on the answer by Persivefire about birds. It depends on finding dinosaurs that are the ancestors of geese or ducks. It involves the process of imprinting. Individuals have used this to convince hatchling geese that they are the chick's parent with some spectacular results. > > Biologist is Real-Life Mother Goose > > > <https://youtu.be/MxxrDEbtuag> > > > Of course you would want to choose a non-predator. 2. Additionally predators can be selectively bred relatively quickly, as I mentioned in a comment above. I've reproduced it here. > > In fact domestication doesn't necessarily take centuries. Wild > Siberian Foxes have been domesticated by selective breeding in this > experiment which started in 1959 and got good results quite quickly. > "People who have tried to simply tame individual foxes often speak of a stubborn wildness that is impossible to get rid of. ... However, one > extraordinary experiment has found a way to domesticate foxes." > <http://www.bbc.co.uk/earth/story/20160912-a-soviet-scientist-created-the-only-tame-foxes-in-the-world> > . > > > [Answer] Domestication is a process that evolves through centuries, and it must exist a background reason for that. Humans choose to domesticate an animal for their milk, meat, skin, eggs, for security (a guardian dog, for example) or company (you will not likely eat a cat, but you could eat a chicken. Both were domesticated for different reasons). You will need to create a background for the domestication: "why" humans would like to domesticate dinosaurs? Besides, take in consideration the fact that there is not completely needed any of the "Fs" you mentioned. You can have a tiger in a cage as a pet (illegal in some countries, of course). Or have a bird as a pet (in a cage also). Both are in a cage, but if you left the cage door open, one of the animals will fly away and the other will eat you. Circus used to have trained animals (zebras, tigers and lions for example) that are usually not domestic animals, but have enough intelligence to understand the fact that when they perform certain behavior, they get a prize or a punishment, and therefore they react. If you consider (in the scope of your history) the possibility of training a dinosaur (even perhaps not so domesticable), you could choose an intelligent one: I would suggest the Troodon (also know as Stenonychosaurus). It had the biggest brain-body ratio, and (without any other evidence) it may suggest a higher intelligence. Besides, it was (more or less) the size of a big dog. More details about the Troodon in this link: <https://www.thoughtco.com/smartest-dinosaurs-1091961> [![Troodon size comparison](https://i.stack.imgur.com/Ph2JJ.png)](https://i.stack.imgur.com/Ph2JJ.png) ]
[Question] [ Demons represent the seven deadly sins: gluttony, lust, wrath, pride, sloth, avarice, and envy. They seek to corrupt men's hearts in order to claim their souls to torture in hell. Demons actively tempt mortals similar to how Jesus was tested by the devil for 40 days in the desert. They reveal themselves in different ways: a faint, barely heard whisper, a dream, a vision at the corner of one's eye, and so on. Through these acts, they promise an individual their deepest hearts desire, and push them to indulge in their darker tendencies. They encourage acts such as murder, torture, theft, and other things society deems reprehensible. The more an individual listens to them, the more influence a demon can wield over their actions and thoughts. At some point, the person becomes so corrupted that the demon can take over their body manually and manifest into the real world. The demonically possessed individual mutates into a monster, and gains a portion of the demons true abilities, possessing increased speed, strength, endurance, telekinesis, and other random powers specific to the demon.They will continue with their acts of violence until he is stopped by force or the demon is banished. The soul of the individual cannot be saved, and is sent to hell to suffer excruciating torment for all eternity. These facts are well known by society, and have designed counters to prevent it. Faith in Christianity, specifically Catholicism, is the strongest weapon used to prevent corruption. The church encourages strong faith in its people as a way to shield them from being possessed. The stronger a person's faith is in the religion, the more protected they are from corruption. Faith is practiced and increased through regular prayer and worship. Religious iconography and symbols blessed by the church are worn to provide people with limited protection. They are also painted on buildings or other places of worship to ward off evil spirits and their influence. Iconography and symbols are empowered by faith, and only a true believer would benefit from them.This particular religion is the only one known to work, as all other nations with alternative religions have fallen to corruption. All human beings will be tempted by demons at least once in their lives, and Demons tend to prey more on those with weaker will. With this setup, is religious fanaticism a necessity in order to keep people safe and protected against demons? Is a strict and conservative world view the only way to prevent corruption? How much power would the church weird in the daily lives of people? [Answer] Previous question: what power would the Church wield Make an analogy to the United States today. It has the strongest economy in the world, and it is that way in part because of its ability to protect its people and property through such forces as the military and police (the rule of law being generally recognized by economists as the number one factor for a country's prosperity), allowing its people to enjoy many freedoms and economic opportunities that are unparalleled elsewhere in the world. As a consequence, the US has a high immigration rate since many people are lured by the prospect of upward mobility. Now, imagine this - because of a strange new worldwide cultural development, the United States becomes the ONLY country that is able to enforce the law and protect itself from invaders. Now, anyone not living in the US is subject to invasion or crime from threats both within and without. These threats could appear from anywhere and without reason, both from inside and outside of your country. Unless you live in the US. Immigrants would flood our borders and ports, begging to be allowed in. The US would be in a position of complete power over the rest of the world and could ask for nearly anything in order to allow someone in. Your scenario is even more extreme, as the risk of not practicing Catholicism is not only physical, but spiritual. Everyone and anyone would want to do anything for the Church in order to protect themselves, their children, and more importantly, their souls. The Catholic Church would become the only world authority, and its higher-ups (from priests to the Pope) would be in complete control over the people who use their churches, allowing them dictator-level power. "Hey, the Church needs 1000 dollars (or gold, whatever your currency is) to continue protecting you from demons this month, can you do that?" "No, I need to buy food for my kids." "Hey, no problem. You'll be excommunicated within the week and is that a demon over there whispering to your son?" Your scenario is more complicated than that, however. Even though your Church is in a position where it COULD do that, whether it WOULD is another story. After all, the demons can influence priests too, right? So you're in a position where the Church has total power over its members, but for any person to use that power would be inviting damnation. This could lead to an interesting dynamic where some priests, bishops, etc. try to abuse their power and others are honestly servants of God out to protect the common man. Hope this helps. EDIT: Updated question - is fanaticism a necessity? Well, yes and no. A much stricter society would certainly develop, as even a small wrongdoing, such as going out for a one-night-stand or fighting your brother, could potentially lead to demonic possession. As such, the Church would start to issue regulations on most aspects of daily life, but unlike last times this happened, the people would willingly and gladly obey them, knowing the consequences of disobedience. However, I wouldn't call this fanaticism, as a religion practiced worldwide where everyone is happy to comply to protect each other's safety more closely resembles something like a national security tax - yes it's a tax and people lose money but everyone is okay with it because of the benefits it provides. Unfortunately, fanaticism could develop where a couple of priests start to become more and more violent in their efforts to control sin. However, these groups of fanatics would die off as a rogue priests who coerces people into compliance through threats or physical violence would be a prime target for demonic possession and subsequent damnation. So the Chruch would need to be careful finding ways to enforce a holy lifestyle without becoming overzealous or cruel. [Answer] # Power Absolute I would invite you to take a look at the Warhammer 40k universe as an example of how far the power of a religion that has tangible and quantifiable benefit can extend. Although not everything you find there directly applies to your question, as it is an amalgamation of a thousand different tropes, there are some clear parallels that can be drawn. ## Religion as a Shield One of the major themes of 40k is the struggle of mankind against their darker nature personified by the four Chaos Gods, and the various demons that serve them, that reside in an alternate dimension called The Warp. It is their ultimate goal to corrupt the entirety of humanity, and ultimately consume all of reality itself. They do this though the typical means, promises, lies, and exploiting the weaknesses inherent in the human nature. Once an individual has been seduced into their service, they have pledged their very soul in the service to the darker powers. Those with a stronger will may be willing accomplices, while others are noting more than unknowing puppets being guided by an unseen hand. Regardless, these agents seek to destabilize the veil between reality and The Warp until their demonic patron can materialize, often at a disastrous cost to the mortal. A typical human stands no chance to resist the power of these demons. Human minds are a weak thing, and it is only though the power of the God Emperor of Mankind, and the strength of the faith in Him does humanity persevere. His power shields the minds of His followers, and acts as a barrier to the power of the Warp. Because of this, the Cult of the Emperor is present everywhere where humanity has spread. It is an ever-present and oppressive constant of human existence. The only alternative to worshiping the Emperor is to become food for the monsters lurking behind the veil. And while most would recoil at the thought, some among the downtrodden masses falter at the promise of something different... ## The Result The Cult of the Emperor, called the Eclesiarchy, thus wields immense power among the daily lives of the people. Their word is law, and to go against them is to be declared heretic, or worse, corrupt. Essentially, they dictate what constitutes worship of the Emperor, and are the ultimate authority on the subject. It is entirely within their power to start a planet wide witch hunt, or to demand that a new cathedral needs to be city sized to appropriately worship the Emperor. Of course, the actual power structure is more complex than this, and depends heavily on the planet in question/who wrote the particular story your are referencing. But this should give you an approximate idea of their power. Looking at the larger picture of the entire galactic empire of the Imperium of Man, the Esclesiarchy forms one of the main power groups that govern it. Basically, unless they step directly on the toes of one of the other groups, they can do whatever they want. Besides the Emperor, there is no other group that wields more power than them. [Answer] ## Priests as therapists A society where people bottle up their emotions, squash that jealousy about your sister, smother your burning hate for the way your neighbour lets his dog yap all night...that sounds like a prime material for the deamons to work with and a way in. So a person's faith would need to be about opening up to someone (probably a priest) regularly - like confession but with a bigger emphasis on talking things out and less on punishment. This would put the church in people's mental health too. People now trust their priests a lot more and they become real leaders of the community but not through fear or squeezing them for cash. The governments, on the other hand, really don't get an option and have to fork out the money (withdrawing the priests from a town would give them evidence enough they need to continue paying the church and listening to their ideas). There won't be much room for other worship, however, you can't have anyone on the fence about what they believe - you're only as strong as your weakest link. The church would, essentially, rule whatever country it was in. People would regularly visit their priest and be reporting any strange behaviour their neighbours may be exhibiting. The fear of deamons would be great enough that the priests only need claim a person is on the brink of turning and they could have them killed or at least contained - whether that was true or not. [Answer] # This is not necessarily untrue as applied to reality There are lots of people who believe the real world works this way. You may not agree, but given that these people [form a significant segment of the human population](https://en.wikipedia.org/wiki/Catholic_Church_by_country) (about 20%, to one sig fig) it seems a little hard-headed to discount their history out of hand. Given that the Church seems to report that your scenario corresponds, in a very rough manner, with real life, it seems reasonable to look at what the Church teaches its role in real life is as a guide to what the Church's role would be in this fictional world you are developing. The Church has [a lot to say](http://www.vatican.va/archive/ccc_css/archive/catechism/p123a9p4.htm) about the raison d'être of the ecclesial ministry. A summary is given in passage 879 in the linked section of the Catechism: > > 879 Sacramental ministry in the Church, then, is a service exercised in the name of Christ. It has a personal character and a collegial form. This is evidenced by the bonds between the episcopal college and its head, the successor of St. Peter, and in the relationship between the bishop's pastoral responsibility for his particular church and the common solicitude of the episcopal college for the universal Church. > > > To elucidate a little, the previous passages state: > > 876 Intrinsically linked to the sacramental nature of ecclesial ministry is its character as service. Entirely dependent on Christ who gives mission and authority, ministers are truly "slaves of Christ," in the image of him who freely took "the form of a slave" for us. Because the word and grace of which they are ministers are not their own, but are given to them by Christ for the sake of others, they must freely become the slaves of all. > > > 877 Likewise, it belongs to the sacramental nature of ecclesial ministry that it have a collegial character. In fact, from the beginning of his ministry, the Lord Jesus instituted the Twelve as "the seeds of the new Israel and the beginning of the sacred hierarchy." Chosen together, they were also sent out together, and their fraternal unity would be at the service of the fraternal communion of all the faithful: they would reflect and witness to the communion of the divine persons. For this reason every bishop exercises his ministry from within the episcopal college, in communion with the bishop of Rome, the successor of St. Peter and head of the college. So also priests exercise their ministry from within the presbyterium of the diocese, under the direction of their bishop. > > > 878 Finally, it belongs to the sacramental nature of ecclesial ministry that it have a personal character. Although Christ's ministers act in communion with one another, they also always act in a personal way. Each one is called personally: "You, follow me" in order to be a personal witness within the common mission, to bear personal responsibility before him who gives the mission, acting "in his person" and for other persons: "I baptize you in the name of the Father and of the Son and of the Holy Spirit . . ."; "I absolve you . . . ." > > > And, in non-Catholic language, this is talking about how the priests and other priest-y people exist to operate in a role of service to God and their community, how they are each individually in charge of carrying out God's will and doing priesty stuff and can do that stuff all the time without needing permission or anything, but also how they are a group and need to talk to each other and such, and should take the counsel of the body of which they are a part very seriously, especially the Pope, who's, like, special. So that's how the Church says things are supposed to go, on its end. On the laity's end, we have: > > ### The participation of lay people in Christ's priestly office > > > 901 "Hence the laity, dedicated as they are to Christ and anointed by the Holy Spirit, are marvelously called and prepared so that even richer fruits of the Spirit maybe produced in them. For all their works, prayers, and apostolic undertakings, family and married life, daily work, relaxation of mind and body, if they are accomplished in the Spirit - indeed even the hardships of life if patiently born - all these become spiritual sacrifices acceptable to God through Jesus Christ. In the celebration of the Eucharist these may most fittingly be offered to the Father along with the body of the Lord. And so, worshipping everywhere by their holy actions, the laity consecrate the world itself to God, everywhere offering worship by the holiness of their lives." > > > Which, in non-Catholic terms says something like: Everything done by normal people is a part of their relation to God and by extension their role in the Church. It is the role of normal people to live in such a manner as to make holy everything they interact with, especially themselves. Which makes the point that almost everything involves the Church and Her actions, even if it doesn't obviously involve a priest. So the influence of God and by extension the Church in the hearts of the faithful (i.e. "lands not overrun by demons) is very big, but not so big as to exclude or obviate personal choice and self-expression. What limits the interference of the ecclesial ministry in the lives of the laity, then? > > 1902 Authority does not derive its moral legitimacy from itself. It must not behave in a despotic manner, but must act for the common good as a "moral force based on freedom and a sense of responsibility": > > > > > > > A human law has the character of law to the extent that it accords with right reason, and thus derives from the eternal law. Insofar as it falls short of right reason it is said to be an unjust law, and thus has not so much the nature of law as of a kind of violence. > > > > > > > > > 1903 Authority is exercised legitimately only when it seeks the common good of the group concerned and if it employs morally licit means to attain it. If rulers were to enact unjust laws or take measures contrary to the moral order, such arrangements would not be binding in conscience. In such a case, "authority breaks down completely and results in shameful abuse." > > > Now, then, we've looked a bit about what the Church says about itself in real life, now lets look at what's different between your reality and the Church's description of reality. 1. "[demons] encourage acts such as murder, torture, theft, and other things society deems reprehensible." -- the Church teaches that demons seek to drive men to evil, death, and ultimate destruction, and that their influence doesn't have that sort of 1:1 correspondence with 'societally unacceptable'. For example, the Church advocates for theft as a superior moral option in certain extreme circumstances, and thus the idea that demons would encourage persons to commit theft in such circumstances is kinda off from Church teachings. Furthermore, subverting evil social discourse and promoting good social discourse is pretty important in Catholicism. Basically, the Church says Society, even when in communion with the Church != Good and thus counter-social stuff might be irrelevant to the evil of demons, while socially ellipsed issues might, in fact, be really important and targeted by demonic influence. If the world worked more like what you were saying then the demons in corrupted lands would operate kinda strangely, since once murder is normal it no longer is something they can push for. 2. "The soul of the individual cannot be saved, and is sent to hell to suffer excrucitating (sic) torment for all eternity" The Church teaches that God ensures that this only describes persons who die in a state of fundamentally rejecting God. While that might be along the lines of what you are suggesting, the spiritual mutation and such make it sound more like this a possession-type thing, and possession is definitely something the Church says is reversible (c.f. Jesus's exorcisms in the Bible, and the exorcism performed by Tobit as instructed by the angel Raphael, and possibly Paul in Acts 16:18). The immutability here implies that something about your possession process involves voluntary destruction of the will on the part of the possessed, which is a little weird. 3. " Faith in christianity, specifically catholicism, is the strongest weapon used to prevent corruption." -- The Church teaches that faith in God is vastly more important. Presumably that's what you meant, because changing that would make the statement self-contradictory ("Belief in and adherence to A greater than belief in and adherence to B is the best means of salvation. A is (stuff) and greater adherence to B than A"). 4. "This particular religion is the only one known to work, as all other nations with alternative religions have fallen to corruption." -- almost but not quite. The Church's position on 'other religions' is pretty complex, but this is close enough I don't think there would really be necessarily any impact at the level of accuracy we're functioning at. 5. "Demons tend to prey more on those with weaker will." -- tradition, in my understanding, holds that it's those with stronger wills and faith and such that are more demonically tempted. The weak-willed don't really need any encouragement to go commit sins, and as long as people are persisting in a state of mortal sin the overall goal of evil is served. This difference is kinda a big deal, because it would mean that the Church's particular relevant ministries would need to be reorganized to serve a very different demographic. Other than those, though, the stuff should all be applicable, and those don't seem like they'd change terribly much from a non-Catholic perspective, I think. [Answer] I think your assumption is incorrect, which actually provides for more interesting narrative paths to explore. Fanatacism is not the mark of strong faith, it is the mark of brittle and weak faith. In effect, I think some demons will be hiding in plain sight as religious fundamentalists, and the question of who has a real shield will be far less obvious... until it's too late! It has always struck me as odd that religious fundamentalists attempt to stomp out everything which reminds them of temptation. It's a policy akin to having someone grow up in a sterile bubble; of course when they are released into the real world it will be a disaster because their immune system has never been exposed to disease. Incidentally, people seem to react to sin almost as if it were a disease. Sinful individuals have to be pushed out of the community, it's as if they were contagious. But if true faith immunises one's morals against corruption... then clearly those who seek to remain pure through ignorance and isolation must have less faith even than agnostics! If someone really has strong faith they can be exposed to temptation, and it will be like water off a duck's back. They will be able to debate and learn about other things, which will help them to alloy their faith with experience and knowledge. The more philosophical and learned the individual, the more likely that their faith will be substantial, as they have sought out and passed many challenges. Where does strong faith come from? Clearly through exercising it. Just like any other skill or talent, one must practice. How can someone who actively avoids challenge have better faith? That's the mentality of fanaticism; intolerance of exposure to challenge and creation. It beggars belief that one may consider the universe to be God's will, and yet to show absolutely no interest in learning about it; and thus the nature of God. A strictly conservative world view is closer to the deadly sins of pride, sloth, and wrath than you may think. I'm not sure Catholicism is the right church, or even Christianity necessarily the best religion, to express the characteristics we need for a strong faith. One could venture that Judaism is more scholarly, and thus its philosophical character helps to make it a stronger faith. If any church encourages loyalty to doctrine above individual dedication to faith, then they're far more likely to be corrupted than saved. The overtly zealous church may actually be a hive of corruption! [Answer] The answer is *it depends on religion. To answer the questions very fast... Q: Is religious fanaticism a necessity? A: No, actually with current values it would only make things worse. Q: Is a strict and conservative view the only way to prevent corruption? A: Most likely yes. But not through Faith, but through Cardinal Virtues, Respecting the Ten Commandments, Seven Noahide Laws and other similar spiritual views. Q: How much power would the Church wield in the daily lives of people? A: If it goes 'all in' in Faith, and no methods to apply it's Cardinal Virtues, then it would go in pure dictatorship, poverty and slavery. If it applies Cardinal Virtues, most likely a lot of power at the beginning, then it's monetary power will fade away, probably a lot more than in the present time. The credibility would probably stay intact or increase in that case. First, Catholicism, and as a matter of fact, almost all Christian religions never really used or promoted the Four Cardinal Virtues. Probably because, if they did, there would be less Faith in the Church, and the Church would lose power. Instead, by overly promoting theological virtues like Faith, Hope and Charity, without cardinality, the Church mostly accomplished the ability to increase it's revenues, instead of actually helping people. Theological virtues only work, if they are very well backed by Cardinal Virtues. If theological virtues are not backed by cardinal virtues, it is very similar to how a currency is not backed by gold. And in regards to the question, if say, any religion would promote, and succeed promoting Prudence, Fortitude, Temperance and Justice, no people would be harmed by some hypothetical 'demons', and as a matter of fact, problems like world hunger, people being poor would be solved in single digit years. And who knows, after that, serious space exploration? But that would also mean, the end of [bread and circuses](https://en.wikipedia.org/wiki/Bread_and_circuses). Anyone who would try doing space exploration while keeping bread and circuses would attempt to collapse the Universe, but that's a subject for another story. The only other religion known that would pursue a form of Cardinal Virtues, is Buddhism. With it's Noble Eightfold path. Of course, there is [Tenfold Path too](https://en.wikipedia.org/wiki/Noble_Eightfold_Path#Tenfold_Path). Whether you have the Noble Eightfold path or the Cardinal virtues, they are sending essentially the same message. Avoid the Seven Deadly Sins. Of course, Buddhism was first, 2500 years ago. Cardinal virtues came later through the works of Plato, in it's work, The Republic. Prudence or Wisdom is called to be the Mother of all Virtues. So, to answer the question, there is no need for any religious fanaticism that would imply values like 'Faith, Hope and Charity'. Because if it did, it would only keep the Church's coffers more full, thus indulging in greed, and making more ficticious 'demons' happy. If somehow, 'demons' would appear and drive the world crazy, and Faith would be promoted instead of Prudence, and the Church is here to save you with their faith, then, most likely, the Church is the culprit behind it. If, however, a religious fanaticism, that would imply the application of Cardinal virtues or the Tenfold path(Because Ten sounds better than eight), or even better, the application of the Ten Commandments or The Seven Laws of Noah(Noahide Laws), then it could not be called 'fanaticism' anymore, but become the new normal. To call a 'fanatic' someone who would want to be Just, in God's eyes, is blasphemy. > > "Love justice, ye that judge the earth" > > > Source: > > [en.wikipedia.org/wiki/Paradiso\_(Dante)#Sixth\_Sphere\_.28Jupiter:\_The\_Just\_Rulers.29](http://en.wikipedia.org/wiki/Paradiso_(Dante)#Sixth_Sphere_.28Jupiter:_The_Just_Rulers.29) > > > Love works with Cardinality. Dante Aligheri with the terms Deficient Love, Excessive Love, and Malicious Love, define the Seven deadly sins. > > Allegorically, the Purgatorio represents the penitent Christian life. > In describing the climb Dante discusses the nature of sin, examples of > vice and virtue, as well as moral issues in politics and in the > Church. The poem outlines a theory that all sins arise from love – > either perverted love directed towards others' harm, or deficient > love, or the disordered or excessive love of good things. > > Source: > > [en.wikipedia.org/wiki/Purgatorio](http://en.wikipedia.org/wiki/Purgatorio) > > > The core seven sins within Purgatory correspond to a moral scheme of > love perverted, subdivided into three groups corresponding to > excessive love (Lust, Gluttony, Greed), deficient love (Sloth), and > malicious love (Wrath, Envy, Pride). > > Source: > > [en.wikipedia.org/wiki/Divine\_Comedy](http://en.wikipedia.org/wiki/Divine_Comedy) > > > Faith, Hope and Charity attempt to guide humanity to love. But with no education to not practice deficient, excessive or malicious love, it is all for nothing. This is why Prudence and Justice are the cure for Malicious love, Temperance is the cure for Excessive love, and Fortitude is the cure for Deficient love. > > The planet Venus (the Morning and Evening Star) is traditionally > associated with the Goddess of Love, and so Dante makes this the > planet of the lovers, who were deficient in the virtue of temperance > (Canto VIII) > > [en.wikipedia.org/wiki/Paradiso\_(Dante)#Third\_Sphere\_.28Venus:\_The\_Lovers.29](http://en.wikipedia.org/wiki/Paradiso_(Dante)#Third_Sphere_.28Venus:_The_Lovers.29) > > > Regarding the Church: St. Peter then denounces Pope Boniface VIII in > very strong terms, and says that, in his eyes, the Papal See stands > empty (Canto XXVII). > > > Within these circles Dante can discern the human form of Christ. The > Divine Comedy ends with Dante trying to understand how the circles fit > together, and how the humanity of Christ relates to the divinity of > the Son but, as Dante puts it, "that was not a flight for my wings". > In a flash of understanding, which he cannot express, Dante does > finally see this, and his soul becomes aligned with God's love: > > > But already my desire and my will were being turned like a wheel, all > at one speed, by the Love which moves the sun and the other stars. > > > Source: [en.wikipedia.org/wiki/Paradiso\_(Dante)](http://en.wikipedia.org/wiki/Paradiso_(Dante)) > > > Through Cardinal Virtues(the equivalent of a compass), Love, Faith, Charity, Hope can be embraced. Edit: Wiki links are now clickable. [Answer] There is a saying that would reflect this "the socialism is on the best way to solve a problem not known in other systems". First of all, you wouldn't have a problem with faith. You know demons are real, so Pascal's Wager is not existing in this world. There is only infinite gain, OR finite gain with infinite loss. So you can be good knowing that there will be reward. So you are guilty of avarice, lust or greed. Or not if in your world such a thing is not considered by divines as such things. Anyway, the second problem is - what about ethics? People who draw their morals from philosophy or just the "not being a dick" movement? Their spine may be even better than those of religious people, because they are more pure in their behaviour (as in: not expecting any reward). Third problem - What if a person strikes a deal with a demon to make good? Find a pot of gold to fund and run an orphanage? Seek knowledge about a poison to help those who have been bitten by a snake or eaten a wrong shrubbery? Will their path lead to doom if they choose it from the start to achieve greater good? Fourth thing - do you need to believe in an artifact for them to work or are they charged and work no matter who uses them? Is the iconography working on it's own as in don't need faith. Or is it need "charging" and if yes does the user need to have faith for it to work and does he need to have faith in the God or just the item? To conclude - there would be no Catholicism all together, because people would just need to believe in God and not the wrapper. Also they would not need to hear stories about foul demons, as they could see them and meet them on an everyday basis. The purest source you would have the stronger your force would be. Also people would die around 200 A.D. as someone would figure that it is better to just use one person who would go to hell to kill thousands of others that would go to heaven. [Answer] Not a complete answer, but just an addendum to whatever situation ends up arising. --- As society eventually reaches the equilibrium[1] where (almost) every living human is either a bodhisattva and therefore free from the worldly desires and temptations that are prerequisites for demonic possession, or a Catholic, you might reach the situation where demonic possessions stop happening altogether. If this happens, people might start to doubt the existence of demons as time goes on, and the necessity of allegiance to the Catholic church would diminish as a result. This would cause those who doubt the existence of demons to lose faith and become more susceptible to possession, thus strengthening the faith of the rest of the community they were part of. Therefore, if humanity doesn't die out, demonic possessions would probably never stop happening altogether. [1] Assuming the human race doesn't become extinct due to demonic rampages [Answer] What are these characters praying to and really why?* If the human characters are constantly harassed by Demons, and therefore they will might be transformed into a monster, they will be hunted down my others of mankind and killed, and THEN sent to actual Hell. The big question here is, why? Why would any of that need to happen just to satisfy the demon, especially when the demon grands you such amazing already when possessed. Is the human still in control at that point I ask? Here's the real problem with this question: Demon are well accepted in this world, that means instead of religion, they are a fundamental part of science in this world, of course. Why practice any sort "religion" if you just need to be good, what is the Demon saying to you exactly? Once the human realizes this demon trying to possess him/her for the very first time, they go to a priest to get it exorcised. This process is totally free because it would be "greedy" for anyone to charge money for such a life-threatening thing, thus making them susceptible to a demon-possession themselves. And then you realize there is no issue in this world at all. Why believe in a "religion," something requires "faith" when it's clear demons exist, both of those things are needed by some real-world people because they need hope in believing it something bigger and greater than themselves, not when something's obviously, scientifically exists. Anything that exists in our real-world and is observable by us humans normally is susceptible to science and data research, thus Demons are explained by "Priests" for some reason. If a demon's "monster transformation" can be seen and explained by science, than you have some tough questions yourself. Really consider this line: "The stronger a person's faith is in the religion, the more protected they are from corruption. Faith is practiced and increased through regular prayer and worship." This takes place in a magical world where holding onto your good side can simply defeat the demon, so why not just teach the victims specifically how to hold on to their own willpower while being possessed if it works over and over. If every bad person is a monster (or dead in hell), then the world is completely populated by good people. Here's a good idea for this story, have a group of characters that uphold the peace who have such "willpower" or "goodness" inside of them, that they entrap the demon that once tried to possess inside their own heart/soul by their own free will. This granted them the demon's powers without being sent to hell, capable of transforming into a "Demon-Monster" due to their own need. It's like you said, Demons represent the seven deadly sins: gluttony, lust, wrath, pride, sloth, avarice, and envy. Each Sin has a super-power attributed to itself, free of charge: Seven Deadly Sins 1. Wrath (red bear) Virtue Patience – Wrath is manifested in the individual who spurns love and opts instead for fury. Users can dismember themselves, piece and piece, and then attach together again by their will. 2. Gluttony (orange pig) Virtue Temperance – Gluttony is an inordinate desire to consume more than that which one requires. Users have telepathic control over rats, toads, snakes, and many other disgusting creatures. 3. Avarice/Greed (yellow frog) Virtue Charity – Avarice is the desire for material wealth or gain, ignoring the realm of the spiritual. Users can be boiled in oil, for they can harness heat from anywhere and store in their body. 4. Envy (green dog) Virtue Kindness – Envy is the desire for others’ traits, status, abilities, or situation. Users have the control over freezing water, the power of pure coldness. 5. Sloth (blue goat) Virtue Diligence – Sloth is the avoidance of physical or spiritual work. Users can wedge themselves into small pits like a snake, they are very flexible. 6. Lust (indigo cow) Virtue Chastity – Lust is an inordinate craving for the pleasures of the body. Users smother their enemies with flames and brimstone, control over fire. 7. Pride (violet horse) Virtue Humility – Pride is the excessive belief in one’s own abilities, that interferes with the individual’s recognition of the grace of the Angels. It has been called the sin from which all others arise. Users can be broken on the wheel however many times they want, for they are invulnerable. Despond, the 8th Sin (blackness) – Outlook of gloom and despair, chronic hopelessness, the question “What difference does it make?” [Answer] In this context, Catholicism offers the greatest protection. This implies that other religions do also, it is just less effective. Fanaticism could form around overthrowing other, "weaker" religions, in part for self-preservation. "Allowing" people to practice other religions increases the risk of a demon rising and therefore the risk of that evil spreading. What is unclear is that if this can be actioned in a way that doesn't make the fanatic a target for possession themselves. [Answer] That depends on what you mean by religious fanaticism. 1.If you mean that the people care deeply about there beliefs and incorporate it into daily lives and are deeply offened by those who try to belittle it, then the answer is yes. 2. If you mean that people are vilotent toward those of other beliefs or other wise try to put pesure on others to conform to there views then No. Some things to think about. If only Christian are protected from demons and everyone is tempted at least once, then by the laws of natural selection everyone still alive and human must be Christian. Sense all forms of Christian provide protection from demons there is no need for conflicts for trying to protect are faith because it protects us from demons, because anyone whose views might threaten my protection against demons would probably be taken over demons. [Answer] Several issues with the setup: > > The stronger a person's faith is in the religion, the more protected they are from corruption. ...Iconography and symbols are empowered by faith, and only a true believer would benefit from them. > > > Religious faith is unsubstantiated belief in powerful supernatural entities. When demons actually exist and specific rituals are proven to work, there's no place for faith anymore. There's still a place for faith (or lack thereof) in one's own holiness / standing in good grace (and, consequently, the ability to invoke holy powers). However, Original Sin is a prominent doctrine of the Catholic Church; being a good modern Catholic means questioning your own spiritual strength. It's not very Catholic if the best Catholics are people who never go to confession or do penance. > > The soul of the individual cannot be saved, and is sent to hell to suffer excruciating torment for all eternity. > > > Souls are beyond the scope of human experience (aka "don't exist"), and Catholicism states that contacting the spirits of the dead is [impossible for humans](https://www.catholic.com/magazine/online-edition/praying-to-dead-folks), so any prospect of eternal torture would have as much effect in converting people as right now. > > all other nations with alternative religions have fallen to > corruption. > > > Catholicism is worldwide, [it's even in the name](https://en.wikipedia.org/wiki/Catholicism). It's not a nation. Catholics live everywhere and Catholic missionaries go almost everywhere, and once demons are popping up, the doctrine is going to (maybe, see below) catch on. Also, in traditionally Catholic countries, many people are "cultural Catholics", not literal believers. China with its ~10M Catholics probably has more aggregate belief than Poland with its ~33M. The answers: > > With this setup, is religious fanaticism a necessity in order to keep > people safe and protected against demons? > > > Fanaticism has to be redefined, of course. The necessity of belief for containing the demonic threat will depend on the severity of the threat and the efficiency of other containment methods. Do psych drugs or therapy work well to suppress the urges that cause possession? What about weed or LSD? > > Is a strict and conservative world view the only way to prevent > corruption? > > > Definitely not. Real-life Catholic doctrine changes, have changed and will change, it varies form place to place, from priest to priest, and it will stay internally contradictory at all times. The abstract deadly sins can be argued (the Catholic Left certainly does so) to suffuse conservatism. It can be argued that, for example, universal basic income reduces Greed and Envy; masturbating to porn is less Lustful than secretly imagining your friend's girlfriend naked; and living off capital instead of working is basically inviting Sloth to turn one's body into a sack of semi-sentient lard. > > How much power would the church weird in the daily lives > of people? > > > Anything is possible. The church as an organization could gain power, it can be co-opted by governments and lose power, it can completely dissolve in the face of factual knowledge. Considering that Wrath is only one sin out of seven, demons and demonic hosts which don't go on rampages can collaborate to suppress both the church and believers. You decide what works best for your story. ]
[Question] [ Using only what is available in the 18h century, across any culture, what might airships look like in such a culture, assuming that an inventor used the resources he had to create one. [Answer] Sorry but no. No [aluminium](https://en.wikipedia.org/wiki/Aluminium) and no [internal combustion engines](https://en.wikipedia.org/wiki/Internal_combustion_engine) means no airships. * You must have aluminium -- there is no substitute for its combination of strength and lightness; and to smelt aluminium you need copious amount of electric power, which was not available in the 18th century. The [Hall–Héroult process](https://en.wikipedia.org/wiki/Hall%E2%80%93H%C3%A9roult_process) for smelting aluminium was invented in 1886; before that aluminium was more expensive than gold and silver. As an anecdote, emperor Napoleon III of France "is reputed to have held a banquet where the most honored guests were given aluminium utensils, while the others made do with gold", or at least so says Wikipedia. * You must have internal combustion engines -- there is no substitute for their high [specific power](https://en.wikipedia.org/wiki/Power-to-weight_ratio). Steam engines are too heavy; they need large high-pressure boilers, they must carry the water with them in addition to the engine and the fuel, and open flames don't mix well with hydrogen (or they mix rather too well, depeding on the point of view). The first primitive internal combustion engines were invented right at the end of the 18th century, with practical engines appearing towards the middle of the 19th. The Diesel engine (which was actually used on actual airships) was invented in 1892. Some comments suggest that wood may be used to make the structure of airships. There are after all [historical examples](https://en.wikipedia.org/wiki/List_of_Sch%C3%BCtte-Lanz_airships) of airships with wooden structures. The first problem is that, as the linked Wikipedia article says, "the airships became structurally unstable when water entered the airship's imperfectly waterproofed envelope, [...] during wet weather operations". The second problem is that [above a certain size] "the superiority of aluminum (and later duralumin) in tension was more important than the superiority of wood in compression". It's the same as with airplanes: small airplanes can be made of wood, larger airplanes cannot; for airships this is even more important, because in order to be actually useful airships must be very large. (I have converted the comment into an answer as advised by user Shokhet). [Answer] The first demonstration of a prototype balloon was in 1709 (Father Bartolomeu de Gusmão). The world's first air force was founded 1793 - French Aerostatic Corps Option 1: Take Father Francesco Lana de Terzi's vacuum design (1673), and permit money and time to be focused upon it. Option 2: A variant of Lieutenant Jean Baptiste Marie Meusnier's balloon ship with bird-like attachments (1785). Option 3: A glider type of ship (Swedenborg, 1716), taking advantage of the ability to dynamically fly (which would have to be learned). Option 4: A combination balloon glider - that uses its ability to change altitudes to gain switch direction and engage in dynamic flying with fixed wings. All of these are possible in the 18th century - they just needed funding and focus to make them happen. [Answer] Steam engines have problems of weight once you include the boiler - and 18th century materials technology REALLY wasn't up to the sort of pressures you need in a flash steam (or water tube) boiler. However, there has been at least one pedal-powered airship! Make that at least two ... the [White Dwarf](http://home.teleport.com/~reedg/whitedwarf.html), built in 1984 [![enter image description here](https://i.stack.imgur.com/brjZO.jpg)](https://i.stack.imgur.com/brjZO.jpg) piloted by Bryan Allen, famous for flying the Gossamer Albatross across the Channel in 1979. I believe White Dwarf still has the world record flight (58 miles) for pedal powered airships, and cruises at 6 or 7 knots. and [a French one](https://www.theguardian.com/uk/gallery/2008/sep/29/france), on which Stephane Rousson apparently failed to cross the Channel in 2008. It's not totally beyond belief that one could be built using 18th century materials - very light woodwork or bamboo, silk, and hydrogen gas - though performance might be less than modern standards. [Answer] How might airships be made using 18th century technology? I think the answer is: using 1920-1930 aerodynamics and flight mechanics knowledges, late 18th century steam engines knowledges, wood and fabric. Remember Clement Ader's 1890 steam engine produced 20hp for 51kg, which is 2.5kg/hp, while Wright brothers 1903 internal combustion engine produced 12hp for 75kg, which is 6.2kg/hp. An 18th century Watt's double action piston steam engine, made out of steel, could have produced enough power. Even if it was 20hp for 150kg (7.5kg/hp) Put such an engine on (let's say) a 1930 Piper Cub, or a Fiesler Storch, and it will fly. A Piper Cub is mostly made of wood and fabric, which was doable in the 18th century. Main problem was the lack of knowledges in aerodynamics, but if guys like Otto Lilienthal, Wright brothers and Gerhard Fieseler were born in 1750, and met an other steam engine genius, then first human heavier than air flight could have been achieved in late 18th century. [![watt double action steam piston engine](https://i.stack.imgur.com/J0Ky6.gif)](https://i.stack.imgur.com/J0Ky6.gif) [![piper cub](https://i.stack.imgur.com/5SZHu.jpg)](https://i.stack.imgur.com/5SZHu.jpg) [Answer] They might be able to build zeppelins, as they do not require a lot of technology to make. They could be made with layers of textile, which has been made airtight with beeswax. Or as dot\_Sp0T commented, use goldbeater's skin to reduce the need for beeswax (I think it will still be needed to seal up the seams). The propulsion could be done with wooden propellors, powered by manpower. Moving down could be done with having a hole at the top that can be opened or closed, and moving up could be done by a system of a fire heating air inside the balloon. ]
[Question] [ Imagine a scenario in which most of the world population falls asleep in, for example, the year 2020. It happens at such a global scale and rate that no one realizes what is happening, except for the few who stay awake after this hibernation takes place. After a few years, everyone wakes up simultaneously, by the combined effort of the awake people to break them free from their slumber. Let's say that the ones that were asleep are in more or less the same condition as they were before they fell asleep, so they received nourishment and such. They do not remember the sleep, for them it is as if they woke up from a nap or good night sleep. Is a scenario conceivable where the majority of the population never knows/comes to realize that they have been asleep for a couple of years? There are several indicators I thought of, and I have the feeling I'm missing a lot more. What should be done to make the world believe that nothing really happened and that they are still in the year 2020? What I thought of that could be difficult to write around: * Season change * Clocks (in many different forms) * Earth's position relative to stars etc. It might be possible to cut down years to months, but that does make it difficult regarding seasonal changes. Earth is Earth as we know it, no magic but advanced technology (more than we have now) is allowed. [Answer] If only a few stay awake, how will they manage to keep the world running? Imagine power plants suddenly without workers. All houses, building, man made structures, they'd all weather without the constant maintenance. Most fields and crops are withered. Cattle has either freed itself or perished. Planes dropped from the sky, because the pilots took a nap, trains, busses and cars crashed. And that's only the beginning. Astronomers look at the sky and see the difference, the ISS may even have entered the atmosphere, because it requires constant corrections to its path. Whole scientific experiments gone mad. And many many more. There are some TV shows that paint the Life after Man, that'll give you an idea what happens. So, your small group of caffeine junkies who didn't fall asleep have to clean up all this mess until the others are waking up again. And last but not least: You have to keep the non sleeping ppl from talking. The first thing they'd do when the majority are waking up again is asking what happened to them and then tell the story of the last year(s) [Answer] I'm going to turn your question on its head a bit. I will ignore whether it is possible to deceive the public short-term, and instead show that someone, somewhere, will figure it out in the long-term. The first clues could come from a variety of sources: The astronomer. You mentioned it yourself, the position of stars vary during the year, which you can get around by having the sleep/wake event happen at the same time of year. However, stars also undergo [proper motion](https://en.wikipedia.org/wiki/Proper_motion). This motion is so slow as to be practically imperceptible, but with careful measurements and improving telescopes, we have been observing this phenomenon for a few hundred years. One careful astronomer will observe that 61-Cygni is 0.01 arc-seconds further ahead (for example) in the sky than it ought to be. The entymologist. Again as an example, suppose the last emergence of the [periodic cicada](https://en.wikipedia.org/wiki/Periodical_cicadas) was just five years ago. Now they are emerging again. It's supposed to be 13 to 17 years between, so what happened to the missing 8 to 12 years? The meteorologist. Similarly, just last year the [El Nino cycle](https://en.wikipedia.org/wiki/El_Ni%C3%B1o) was winding down, now it seems to winding up again. Let's blame it on El Nino! The guy who monitors nuclear fuel rods The output readings seem to have reduced pretty suddenly. This stuff is supposed to have a much longer half-life than this. Erosion, decay, growth, and so on. The clues may be subtle, but they will be many. Humanity will eventually put it together and figure it out. [Answer] This requires one thing for sure: Someone who keeps everything running during the hibernation. And that someone needs to have quite some power and must definitely be a perfectionist. ## Traffic What happens to a train, if the train engineer suddenly decides to take a nap in the middle of the track? Well, most modern trains (not so modern to be honest) have measures against crashes in that case, but there definitely will be cases, where this ends ugly. Or consider a highway. Multiple crash, here we come. That one guy whos going climbing has definitely lived the longest part of his life, if the hibernation kicks in while he's on some climbing track. ## Power supply Consider a nuclear power plant without engineers. That won't work out that well for all too long. Noone wants to wake up on a planet that basically became uninhabitable by hundreds of meltdowns. On the other hand for noone to notice the hibernation, the whole infrastructure needs to keep running. It'd be a bit weird, if you took a nap and woke up to a global blackout. And quite a few sorts of energy-infrastructure require regular maintenance or even fueling to be kept running. This goes from power supply lines to entire power-plants. ## Fauna A few years are definitely enough time for the sentence "nature takes back what is its" to come true. Larger cities already have issues with everything from rats to bears, which are attracted by cities as synanthropes. Now wait a few years without any humans being in the way and the city will have plenty of inhabitants that weren't there beforehand. Pets, especially carnivores like cats (not that much) and dogs will definitely impose a problem. So you've somehow got to keep fauna at bay. On the other hand going to sleep and waking up with the skeleton of your beloved brutus in the living-room would be suspicious to say the least as well. This is one of the simpler problems to solve: hibernate the animals as well. ## Flora Googling for what Chernobyl looked like in 1990 should give you a vague impression of what happens to a city, if noone is there to care about it. You'll need an army of gardeners to stop this problem from getting out of hands. Especially since plants will start to dissolve streets and buildings over a few years (tree roots, etc). You might have a really nice looking city with a lot of green areas, when waking up again from hibernation, but I guess most people will notice. ## Time keeping One doesn't need to be astronomer to immediately notice somethings not all alright, when looking at any electronic media. Every PC has a built-in battery that keeps it's time-keeping chip alive. While that battery will die sooner or later - another problem - I'll at least notice that my PC will notify me about the fact that the battery ran out of power and the fact that the clocks a few years off. As soon as we use a bit of astronomy, we finally get to the point where this will finally get entirely undoable. ## Resources Keeping the world in a fully functional state requires resources. Be it batteries, fuel, replacements, tools, somehow all will need to be produced. Now imagine the power-plant topic: An uranium-mine that overnight gets entirely exploited will for sure look fishy to someone. Same goes for production of batteries. Basically quite a large part of the economy would have to be kept running in order to prevent people from noticing anything suspicious when they wake up. Which itself will produce noticeable results. The larger the required amount of resources, the more noticeable the results. Transportation of goods to their destination requires fuel, which run short pretty fast, if not replenished, which in turn drains an oil-field. "We're missing several bio barrels of oil" is definitely a result you won't be able to hide. Etc. etc. So in short: Hiding the results is only partially possible at all. And even that "partially" requires an army of perfectionists rather than a few people that escaped hibernation. Keeping this world running requires 7bio people in it's current state - well, that's a bit of an exaggeration, but I think you get the problem - keeping it in the state it's currently in won't require much less. [Answer] Basically everything can be used as a clock, even the average household has many things that will roughly indicate how much time has passed. The fridge, and its contents. You'd roughly know whats in your fridge and none of it will keep for years. Any battery powered device will have dead batteries after a few years and a few of these batteries will leak, damaging the device or at least leave the telltale signs of the leak. If you own a PC, there is a good chance the battery (there is one for the clock) might kill the mainboard. Many electrical components also have a limited life time, for example capacitors will dry out and fail as soon as powered on. Even if its only a few years, all the power supplies that would have naturally died over these years would now die the moment they're turned on, a notable spike of dead power supplies. Looking outside, the growth of trees would notably change a cities face, even if all the houses were perfectly maintained in their current state (which would present a challenge all by itself). If you owned a car or motorcycle, its oil and fuel would degrade to a point where it would render the engine inoperable after some years. And also, anyone you knew that didn't fall asleep would have aged visibly in a few years (especially if they were kids or teenagers). If the sleeping people age normally, many would notice it by simply looking into a mirror. A multitude of other things, technical or natural, would also show the passage of time. Many of these (as the mentioned astronomical measurements) would be completely outside humanities influence and impractical to deceive/hide. In conclusion, the passing of time is near impossible to hide. It would be much simpler to just construct a lie about the reason (I'm assuming thats what you really want to hide) than to try to hide the fact that time has passed. [Answer] Actually they would know very quickly. You couldn't hide this. 1. Entropy. Most man-made things (houses/apartments, cars) were not made to last on their own. Many houses would completely deteriorate; the furniture would break down after 10 years. So it would be pretty clear almost immediately that something had happened. 2. Nuclear Power Plants. Nuclear power plants require working staff ready to step in in the case of an emergency to prevent a meltdown. If all the staff are unconscious then nothing is there to stop a meltdown during the ten years that everyone is asleep. I think you can see how bad this would be. 3. Fuel refineries. Again these require human intervention to keep running. Without humans there to monitor it or shut the factory down, chances are the fuel would ignite fires which could burn for months without human intervention. Look up Life After People for more information. [Answer] Perhaps you can convince the population that anyone who thinks something happened has a mental illness. Most everyone would then keep their suspicions to themselves for fear of admitting that they were crazy. The brave ones who point out things like the Earth's position relative to the stars would be publicly mocked and locked up in asylums. Other "experts" would present counter evidence that's plausible enough for the average person to believe. So most people would know something happened, but nearly all would deny it. [Answer] First, a great idea. The problem is the practical issues, as you suspect. Besides everything decaying/breaking/exploding -- as mentioned in other answers -- everything would be covered in a thick coating of dust. Not to mention that people who fell asleep in bathtubs, pools, the ocean -- or even on the beach -- would drown and people who fell asleep outdoors might well die from the cold, be eaten by animals (unless they, too slept), or be sunburned beyond recognition. And security cameras all over the world would have recorded either sleeping people or emptiness for as long as they were powered. (Probably overwriting in a loop, so you'd only have the last few days or weeks.) [Answer] Without anti-aging in some way thousands and thousands of people would die. Their bodies would either decay or have been moved. Both would pose issues you could not get around. "Millions of people die in their sleep!" Would read the papers, or perhaps "Millions of people missing overnight!". [Answer] Beside the decay of everything the man have build. Wonder why no one mention New Orleans and Netherlands be under water Im worry about natural disaster, how will you able to hide a volcan eruption, earthquakes, tsunami or forest fire. [Answer] Build thousands of large EMP (electro-magnetic pulse) weapons and fire them before the waking up, to destroy all electronics. Then blame it all on a sudden solar event. With all electronics destroyed, it will be a few years before anyone will be able to make precise enough measurements to figure out what really happened, even though there may be small signs like mechanical clocks that raise suspicions. Of course this will not result in the people thinking that nothing happened, but it should hide the side effects of the hibernation pretty well. It is not inconceivable that a strong enough solar storm might kill a few people and make buildings weather a bit. ]
[Question] [ I've got to admit: I'm asking this mostly because the question amuses me. Imagine a world (herein known as Whatworld) which is identical to Earth before the rise of humanity. It is populated by the same spread of creatures, with one important difference: The 'homo-sapiens' analogue (homo-whatvia) has no cognitive ability to think in hypotheticals. Questions like 'what if' and 'could we' don't occur to them. They're still very logical, and can infer, extrapolate and learn from example, but they can't answer or ask questions that require a hypothetical component/assumption.. For example: When a lightning strike lit a nearby tree on fire a nearby tribe of Homo-Whatvia learnt that making things hot could set them on fire, and fire was hot, so fire could make fire, which was useful in some ways and not in others. What they didn't do was engage in speculation about whether they could make things hot any other way, and the only answer they could give when one of them asked 'Does anyone know what caused the lightning?' was 'Nope'. Can Homo-Whatvia progress along a similar track to homo-sapiens, or is the lack of hypothetical situations going to prevent them from progressing at all? [Answer] It really depends on where the line is drawn exactly. If I work with what I consider to be hypothetical thought-processes, humans never survive. Anytime you think about doing something before doing it, you could be engaging in a hypothetical. Your mind considers, "How does the situation change if I take this action." This could be rephrased as, "What if I [took this action]", and your mind responds, "[something like this] should happen", which is either better or worse than your current situation. If it's better, you'd likely take the action. Seeing the bolt of lightning start a fire, and the fire spreading, we might learn, "Fire spreads." At that first moment we will continue doing what we were doing before, (presumably, just sitting there.) The fire starts burning Kevin as he sits there. Kevin cannot think, "What if I move away from the fire". He can't even comprehend what would happen if he were to move at all. All he has learned is, "Fire causes heat, then pain". Kevin dies as everyone sits there watching. Everyone now learns that fire kills. But nobody can tie "running" to "not dying", because nobody can ever tie how any potential action affects their real-life situation. Humans then die out almost immediately. Unlike single-celled organisms, we do not have enough hard-wired action/reaction responses to actually sustain ourselves. If we did, babies would not need us to care for them while they learn the skills they need to survive. (Skills they would not learn, in this case) [Answer] I think the final result is that they must live in harmony with nature. Defining this world is going to take a tremendous leap of faith to define what "no ability to think hypothetically" means at a biological level. Once we have that, we can extrapolate out to what that would mean for the species as a whole. Of course, the real challenge is that basic thought requires some level of thinking which might be seen as hypothetical. If you eat food, your body observes inputs though taste and smell and does its best to predict what sorts of work the digestive tract needs to do. This system is so advanced that you can even get "more energy" through a placebo effect. If you think you just got more glucose, the body/mind will often permit more action on the presumption that more glucose will hit the small intestine shortly. Its really hard to live without this (in fact, by some definitions of "life," the inability to do this would prevent single celled organisms from forming). Accordingly, we're going to have to carefully sidestep this definition and find another definition of "hypothetical thinking." The definition I find most promising is one which breaks hypothetical thinking into two parts. The first part is where we think of the hypothetical situation, such as "I wonder what it would be like to have soup for lunch today." However, at a biological level, its really hard to separate that phrase from "Soup is happening, the digestive tract moves." Instead, we're going to draw the line differently. The second part of this hypothetical thinking is the ability to discard the thoughts. If you finish thinking through what it would be like to have soup, decide "Nah, I'm having salad instead," you discard the entire mental universe you constructed to explore having soup. But what if you couldn't discard it? What if those thoughts had to continue existing as long as they "wanted" to? Anyone who has unbridled hypothetical thoughts would quickly go insane with the myriad of worlds in their head. I don't define this line by sheer happenstance. This is also one of the accepted lines of reasoning for exploring reversible computing. In the theory of reversible computing, it's not the computation that has entropic costs, but rather the act of erasing those computations. Thus, I can argue that Homo-whavia can indeed think, as well as any reversible computer can think. The biggest challenge with this is that reversible computing is very bad at handling irreversible changes (no surprise there). Accordingly they would develop a culture which avoids considering irreversable changes. Everything would have to flow smoothly from one state to another, permitting them to stop thinking about a "hypothetical" simply by letting it flow outside of them (to be forgotten elsewhere, most likely). This is I think the defining characteristic of such a species. We often say "every action has its consequences." Their version would be much more extreme, for even their most secretive thought must eventually have a consequence as it is permitted to flow out of their minds into the world. This concept of everything having consequences may be so prevalent that the only phrase they can construct regarding the topic is "Consequences are." (manipulating a phrase from Stranger in a Strange Land to suit my fancy) Such a species may survive. In fact, I'd be tempted to argue that there exist religions which actually describe such a world. Daoism believes "everything is of the Dao." The Dao flows through us, and while we perceive a separation between us and the Dao, it is believed to be just an illusion. The Daoist cultures sought long term stability. If a ruler was poor, they would not attack him head on, but allow the flow of time to erode his support until it brought him down to his proper place. The wisest of homo-whatvia would be those which were most aware of their balance within their "Dao." That individual would be so in tune with the consequences of those balances that they might not even more perceptibly. The tiniest flickers of their hands may be enough to keep their world in tune. Any homo-whatvia would recognize that they are doing this, and accept it. However, another species, such as the impetuous H. sapiens might not. They may see the leaders of homo-whatvia as not acting at all. Homo-whatvia would do its best to communicate with us, but that language gap would be significant. They might even have to resort to strange aphorms in their language, which even then might not translate. Perhaps the best communication they could achieve would be... "Waiting is." [Answer] Well, I will take my hypothetical guess. Luckily, in this universe I am able to do it, so lets do it: ## You end up on hunters and gatherers level I think it can be expected, that these hoomans (alternate humans) will figure out by trial and error how to hunt and how to gather stuff to survive. edit: I think that it is plausible to build on scenarios like: "Animal hunts me, I stumble on rock, rock hits animal, animal is dead." Someone else from the tribe can see it and learns that from example (as I understood the question) They might grasp on primitive knives and spears. Also, they might conquer a fire. Maybe they will be able to start a fire by trial and error. I think that you will end before "agricultural revolution" because I think that domesticating of cattle needs some of the "what if" or "what would" in order to even try it [Answer] Without Hypothesis, you've got only Empiricism. A French author, Michel Serres, in his book "Les origines de la géométrie" states that most discovery and invention where made with the help of random. Reaching a peak would then propagate them. One of the possible origin of agriculture, according to Michel Serres could be : There was a great fire that burnt a lot a of space in a forest. Once the place is burnt, its soil became fertile. Then some plants began to grow and populate most of the space left. So Humans concluded : If a forest burns, then some plants will grow later. My guess is, Mankind discovered most of thing randomly and simply trying to reproduce it. [Answer] First, I'd like to use a narrower definition of "hypothetical". Many answers are interpreting it very widely, going as far as including [operant conditioning](https://en.wikipedia.org/wiki/Operant_conditioning) as requiring hypotheticals: * Another human jumped off a cliff and died * What if I jump off the cliff? * I would die; don't jump off cliffs But operant conditioning is such a basic form of behaviour that even [insects](https://en.wikipedia.org/wiki/Bee_learning_and_communication) can do it. Humans without it would indeed struggle to survive let alone develop technology. Instead, I think a better definition would be that hypotheticals requires abstract reasoning, the sort that requires formal education for most people to attain. We have good examples from real life of how these people think; they are very uncomfortable with dealing in pure hypotheticals and have very concrete reasoning. The Soviet psychologist [Alexander Luria](https://en.wikipedia.org/wiki/Alexander_Luria) once interviewed Russian peasants about 100 years ago, giving them the kind of abstract reasoning questions typical in IQ tests, [this is how it went](http://blog.ted.com/are-we-getting-more-intelligent-jim-flynn-at-ted2013/): > > Luria: What do crows and fish have in common? > > Subject: Absolutely nothing. A fish swims, and a crow flies. > > Luria: Are they not both animals? > > Subject: Of course not, a fish is a fish, and a crow is a bird. > > > Luria told another subject: “There are no camels in Germany. Hamburg is in Germany. Are there camels in Hamburg?” The subject replied, “If it’s big enough, perhaps it has camels.” Luria prompted him again to listen to the conditions, and again he replied that perhaps Hamburg had camels. He was used to camels, and he was unable to imagine that there weren’t any in Hamburg. > > > In other words, these humans would think exactly like us, if we were illiterate peasants. So what kind of society can these humans achieve? They would have the same level of general intelligence as us, just as those illiterate peasants are as intelligent as us, except without the benefit of education. If you plop one of them into our world, they are fully capable of surviving and integrating, only that they cannot perform cognitively demanding professions. But a world comprised fully of such humans won't be able to transform into our world, as so much of it depends on modern science which requires abstract reasoning skills. They would still be able to develop a lot of technology, although at a much slower rate. Some would be entirely out of their reach; for example they can be like Edison and repeat thousands of experiments to invent things like light bulb filaments or alkaline batteries, but they can't be like Tesla who invented AC motors, which requires understanding advanced mathematics. It would be hard to precisely define what their world would look like, since we've had abstract thinkers from the beginning. They would have superstitions and very basic myths but no religion like the ones we do. They will have very skilled crafts and traditions, but no philosophers, no scientists, no mathematicians. Such a society should be capable of accumulating a large body of technology, although their development rate would be severely hampered. I can easily imagine their society matching some of our nomadic cultures in sophistication. However, they will hit a developmental wall somewhere around the pre-industrial level, as that's when you need modern sciences like chemistry, physics or advanced engineering to get breakthroughs. [Answer] No progress at all. Animals can learn by operant conditioning: <https://en.wikipedia.org/wiki/Operant_conditioning> This is effectively learning by example: if the animal does this, that happens. We humans have it, along with conscience of our actions. A homo-whatvia without operant conditioning would learn almost nothing, even with developed conscience. For example: Ug is in the forest, collecting fruits. Some foliage ahead shakes, and a tiger breaks out. Ug runs and manages to escape somehow. Without conditioning, the next time Ug sees foliage shaking, he won't be afraid - and his luck will run out someday. I expect that homo-whatvia will be extinct way before any organized tribes emerge. [Answer] No. Progress would stagnate. Any amount of progress requires "what if". Even if you find a fire lit by lightning strike and go "that's warm", you now need a "what if we bring it with us". The same applies to anything else. Without a way to generalize advancement it would go very very slowly and most likely stall somewhere around the hunter-gatherer level. [Answer] Your learning example actually involves quite a few hypotheticals: > > For example: When a lightning strike lit a nearby tree on fire a > nearby tribe of Homo-Whatvia learnt that making things hot could set > them on fire, and fire was hot, so fire could make fire, which was > useful in some ways and not in others. What they didn't do was engage > in speculation about whether they could make things hot any other way, > and the only answer they could give when one of them asked 'Does > anyone know what caused the lightning?' was 'Nope'. > > > The hypotheticals here are, among others: * Fact: When lightning occurs, you sometimes observe fire shortly afterwards. Hypothesis 0: the two phenomena are linked. Hypothesis 0a: one is the cause of the other (rather than both having a common root cause) Hypothesis 1: lightning causes fire. Hypothesis 2: other loud things also cause fire. Hypothesis 3: Other hot things also cause fire. * Fact: After a lightning strike, there is light, heat and thunderous noise. Hypothesis: heat and light have the same root cause, but noise doesn't. * Fact: Fire is hot. Hypothesis: Heat may be useful even though it can also be destructive. Without hypotheticals, you cannot ask questions. This is because every question has some wrong answers, and wrong answers are hypothesis about what could be true but isn't. Learning and planning are both inherently linked to hypotheticals (and to each other, and to asking questions). Without hypotheticals, you are limited to strictly a reactive lifestyle, akin to how ants or bees proceed. [Answer] Even animals can engage in hypotheticals. Can use tools and find un-obvious solutions to problems. Dog which learned to climb a fence to get out from enclosure (there is a video somewhere). Bird which learned to wrap fishing line around something to get the fish out. Sea otter which learned that coke bottle is as good for cracking shells than the rock is, and easier to hold. Apes can invent to use tools (a branch) to get ants from anthill - I am confident it was not learned by observation of humans. Etc. Responding in a new way to a new situation is crucial to evolutionary adaptation. If you remove that kind of response from your planet, life on your planet would not develop beyond single cell organisms, if it will go that far. "What-if" thinking cannot be removed from brain. [Answer] I don't have a long philosophical answer. I simply think that it would lead to a Whatworld with no sentient beings at all, where every organism acts on pure instinct. Not only would there be no homo-whatever type of organism, there'd be no mammals, because "lesser" organisms wouldn't have been capable of asking "what if", either. There wouldn't be anything to evolve from. I mean, even my cat can ask herself "what if". It's pure curiosity. It would basically be a world where the highest intelligence achieved would be up to the level of reptile, insect, or fish (not sharks), if that. Birds are too curious. Maybe we would be ants or bees, since they live in such complexity. I guess we'd have our own jobs, but no ability to live on our own or think for ourselves. Smarter than bees, but dumber than birds. [Answer] Let us avoid the semantics of the term 'hypothetical' and instead base the Homo-Whatvia's intellectual abilities on your example of observing a lightning strike. According to your description, the ability to learn from direct experience and observation is within Homo-Whatvia's ability, but extrapolating from that point forward would not be. This is actually not too bad as far as animal intelligence is concerned; it would place them roughly on par with crows and the lesser primates, both of which can learn behaviors they observe in others in order to accomplish tasks, but typically do not 'invent' novel solutions to problems unless they stumble upon it through trial and error. Humans could survive at this level and might even manage to invent some simple tools, provided some roughly analogous item existed naturally (for instance, some rocks are sharp, sharp rocks are good at cutting, and you can make rocks sharp if you bang them together in the right way), but it would be very, very unlikely that they would move beyond a survival-oriented hunter-gatherer society. ]
[Question] [ I am imagining a world where liquid water can exist outside our solar system and share a similar chemistry with our ocean, say there is traces of sodium chloride in water (not the heavy water kind). I'm thinking of using sonic vibration to force the water to behave like honey in terms of viscosity but I doubt it would be that easy even for very brief moment, any idea what kind of conditions no matter how extreme it gets just to make an ocean of saline solution to behave like honey? In short the chemistry of ocean water must be the same as the Pacific ocean to be accepted as an answer, I can also accept mathematical model but please explain the parameters and principals used. It is for my exotic lifeform whereby streamline is a rarity. [Answer] ### Partially freeze it With temperatures very close to zero, the upper layer of water freezes and ice crystals form. If the temperature fluctuates around zero though, and with waves churning things up, you can end up with a layer of ice slush floating to the surface. As anyone who's eaten/drunk a slushy knows, this is thick and viscous. Of course the lower layers of the sea will not be like this, but the surface could be. [Answer] The only option I can think of that has a remote chance of working borrows a page out of [Riven](https://en.wikipedia.org/wiki/Riven). Have the ocean be chemically salt water but be thickened by high concentrations of microbial life. In Riven they make the water [thermophobic](https://en.wikipedia.org/wiki/Thermophobia) in your case they increase surface tension and viscosity instead. I would suggest a microbe with a surface covering of long hairlike structures that exploit Van der Waals force in the same way that a [Gecko's Feet](https://en.wikipedia.org/wiki/Gecko_feet) do such that the microbes can bind strongly with their neighbours but also separate easily at will. [Answer] If you want water to be as viscous as honey, it had to be some sort of gel. The easiest way to achieve it is probably by dissolving a conspicuous amount of proteins or polysaccharides in it, not much different than what you do when you prepare some stock or broth. How do you get proteins dissolved in water? Well, for example there is a thing called "[sea snot](https://www.intotheblue.it/en_GB/2021/03/17/la-mucillagine-marina/)" [![enter image description here](https://i.stack.imgur.com/D7O0Q.jpg)](https://i.stack.imgur.com/D7O0Q.jpg) which is a [mucilage](https://en.wikipedia.org/wiki/Mucilage) > > Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. > > > [Answer] Your organisms are much smaller than human. [Isaac Asimov wrote the novelization for the movie Fantastic Voyage](https://en.wikipedia.org/wiki/Fantastic_Voyage) but missed a few things (or wasn't allowed to consider them because it would've made the movie impossible); but he wrote about them later. One of them is surface tension. Water sticks to water; the molecules actually attract each other. At human (or even child) scale, this is pretty negligible compared to the force the human can produce. But at smaller scales, like bacterium, 'water' is more like what we'd call "molasses in January". Or "swimming pool full of ping-pong balls except heavy." Pick your scale, and you can have it be 'as thick as you like'. ]
[Question] [ Background: It is the year 2021 and I am a reclusive and enigmatic billionaire with a flair for the dramatic. I would like a dramatic spotlight to shine down on me on command (at night), so that I can look something like this diagram (without an obnoxious helicopter, plane, or blimp above me): [![Spotlight On Person](https://i.stack.imgur.com/MWnDom.png)](https://i.stack.imgur.com/MWnDom.png) Specific requirements for the system: * Must shine down on me from above. Beam can be slightly angled, but the closer to 90° the better. * Radius of the projected spot can be big, but shouldn't exceed 5 meter radius (smaller is better) * Color of the light should be white, and the ability to change it would be a bonus * The system should work anywhere on Earth, but I am willing to time my dramatic appearances for a satellite to be passing overhead. Launching multiple satellites is also an option. My solution so far: I think I'd be able to accomplish this by launching a satellite (or a fleet of identical satellites for better coverage) that is equipped with a powerful laser, powerplant/battery, and targeting system. When not in use, the satellite charges its batteries and then when I want to make a dramatic appearance, I feed it my coordinates or use a laser designator to designate my position. Then, the light shines down on me, I impress people, and the laser shuts off again so the satellite can recharge. Questions: * Feasibility. I'm unsure how difficult it would be to maintain beam coherence over such a distance and through the atmosphere. Additionally, I'm unsure how powerful exactly the laser system would need to be and if a satellite can support such a load * Price. Approximately how much would a system like this cost in today's US dollars including launch costs. Is \$100 million enough? [Answer] Satellites? Blimps? The Six Million Dollar Man? Drag yourself into the millennium! You want a drone! [![drone spot](https://i.stack.imgur.com/H5RBx.jpg)](https://i.stack.imgur.com/H5RBx.jpg) Your drone can hover silently above you. It can track your movements via invisible lasers. Cloud cover is not an issue. It can turn on your spotlight from close enough above you that the beam will not diffuse to lame wideness by the time it hits you. The riffraff you wish to address will not be included in your spotlight. Having an entourage of drones hovering over you at all times has other potential benefits besides dramatic lighting. Drones can come down with leg warmers, or a bottle of Crystal Pepsi or a fresh Cabbage Patch Kid exactly as your needs require. If you are low on soothing tunes you can beckon the tune drone to come closer and serenade you with a little Anne Murray and Neil Diamond. [Answer] It is quite doable, but highly unlikely in the stated budget of \$100m First: the light. 1. You will need a laser, for the required beam collimation.(to keep the spot size small enough) 2. You will need multiple lasers to combine, to form a suitably aesthetically pleasing visible white light color. 3. You will need lasers of sufficient power. 4. You will need a power source for the lasers. 5. You will need targeting systems capable of suitable aim. Include all control systems in this requirement. 6. The light source needs to hang around long enough for your speech, without visibly distorting. This means multiple sources trading off the work, or a much stronger source further out. 7. You will need some means to get the thing launched. #1 About the best we can do with a powerful laser, through the Earth's atmosphere, is the sort of thing used for the [Lunar Laser Ranging experiment](https://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment) which is quite capable of lighting up a 6.5km spot on the moon. Taken in reverse, a satellite at 400km distance can illuminate a 7m spot on earth. Problem #1 is solved. #2 Trivial, just RGB your lasers. #3 We need a good spotlight. For an audience. An impressive but not blinding spotlight. I'll accept MolbOrg's comment above for this. 200Kw Satellite laser power, delivering 20Kw ground power, giving 1/2 daylight illumination over the 7m diameter spot. #4 200Kw consumption is a bit much, that is three times as much solar power as the ISS. Plus, you want the light at night, when a low satellite is likely to be in Earth's shadow. So a modest solar panel for recharging a rather hefty battery pack. Um... 200Kw for 3 minutes would require... one Tesla battery pack. Although the unaltered form will not like that discharge rate! #5 NO problem. We have spy satellites and ground mappers quite capable of keeping a camera pointed at the ground accurately enough to allow long(-ish) exposure photos. Doing the same with lasers is no problem. You even have a very visual feedback system for targeting. #6 This is a problem. Due to the relatively low orbit of your satellites, they are zooming horizon-to-horizon in under 10 minutes. To maintain a spot at all, max about 8 minutes window. To maintain a spot without obviously having a rapidly moving source, you need to have your Sat way further out(thus needing much more coherent lasers), or.. you need to shine the spot simultaneously from multiple sats. #7 If we can keep the mass under 10 tons, a single Falcon9 can hoist it. Costs: A single Falcon9 flight will easily hoist 10 tons to a 400km orbit of your choice for you, costing \$65m. If you use mostly off-the-shelf tech, you should be able to shoehorn in the needed power, control and laser systems for \$35m Be generous, and assume you are not charged for ground control facilities. Yes, you could lob a single such Spotlight Satellite for your use with a budget of \$100. But. It would not quite fulfill your requirement unless you set up a constellation of many such sats. Which will, of course, break your budget. You would need to time your speech down to the second. You would need to limit your speech to under 8 minutes, better under 3 minutes to avoid your round bright spot turning into a fuzzy ellipse of much greater size. And it will be obvious to observers that the light is coming from a moving source. [Answer] Let me compound on [L. Dutch's answer](https://worldbuilding.stackexchange.com/a/196198/21222). You can solve the color problem by using multiple lasers instead of one. You can also solve the problem with orbital speeds by having the satellites in a very high orbit - having 96 satellites in geostationary orbit should allow you to have a nice spotlight effect as long as you don't stray from the equator. Otherwise you would need thousands of satellites in geosynchronous orbit. Keep in mind that though there is no official cost for a geostationary spot, they are given at a first-come, first serve basis. In the 80's some companies were launching satellites to geostationary orbits and renting the satellites for a few million dollars per year each. I imagine that the price would have skyrocketed by now, pun intended. Also keep in mind that you will have things resembling pillars or light, not spotlight cones. This is due to the immense distances involved. Last but not least, I don't know how to calculate the size of satellites you would need for this. I imagine it could be like [ICESat-2](https://en.wikipedia.org/wiki/ICESat-2), a satellite that shoots lasers at Earth: > > ATLAS [Law's note: this stands for "Advanced Topographic Laser Altimeter System"] emits visible laser pulses at 532 nm wavelength. As ICESat-2 orbits, ATLAS generates six beams arranged in three pairs in order to better determine the surface's slope and provide more ground coverage. Its predecessor, ICESat, had only one laser beam. The greater number of lasers allows for improved coverage of Earth's surface. Each beam pair is 3.3 km (2.1 mi) apart across the beam track, and each beam in a pair is separated by 2.5 km (1.6 mi) along the beam track. The laser array is rotated 2 degrees from the satellite's ground track so that a beam pair track is separated by about 90 m (300 ft). The laser pulse rate combined with satellite speed results in ATLAS taking an elevation measurement every 70 cm (28 in) along the satellite's ground path. > > > The laser fires at a rate of 10 kHz. Each pulse sends out about 200 trillion photons, almost all of which are dispersed or deflected as the pulse travels to Earth's surface and bounces back to the satellite. About a dozen photons from each pulse return to the instrument (...) > > > As you see, you'd probably need something orders of magnitude bigger than ICESat-2 (which was a payload of about 298kg), and capable of much tighter focus. [Answer] Why no blimp?!? It's quiet, practically invisible, it can follow you and you can decide whether you want to be mysteriously backlit or resplendently front-lit just by moving it around. They are relatively cheap so instead of having one, you could have one in every city you needed it in and it could come down during the day to re-charge. Everybody else is basically right about the LED lasers, but with a blimp, you'd have options - [Collimated light](https://en.wikipedia.org/wiki/Collimated_beam) doesn't necessarily need to be mono-(or bi- or tri-)chromatic. If you're worried about somebody noticing it, remember - all of the lighting technology has shrunk impressively over the last many years. If a blimp with a 10 m diameter is at 32,000 feet, it'll appear about the same size as a dime at 30 feet. You could automate the whole thing by having GPS sensors on the blimp and the billionaire's phone constantly adjusting both the target of the beam and the origin! Geo-stationary orbit is hugely expensive to get to and you will never be able to adjust the location. If you have a presentation in New York, the angle will be very different from when you're in LA and forget about Shanghai. You'd need to provide all the required power either with solar cells or a nuclear powered Peltier junction. From the back of the envelope, this option would cost 100 times what the blimp cost and it would offer less functionality - not a choice a self-made billionaire would make. [Answer] A few tweaks might be required, but the Soviet Union did something like this in their [Znamya project](https://www.smithsonianmag.com/smart-news/how-russian-space-mirror-briefly-lit-night-180957894/). Basically, they put some reflectors in the sky. In the initial test, they provided light over multiple square miles that had a luminosity 5 or 10 times the moon. So just some additional engineering, and it should work! [Answer] Not feasible in the way you propose it. Color of the light should be white: laser are monochromatic, with a few nm bandwidth. Below you can see a qualitative [comparison](https://www.thefoa.org/tech/ref/appln/transceiver.html) between the spectrum of a laser and the spectrum of a LED. To make it appear white as perceived by the human eye, you would need to cover the whole visible spectrum, which makes for about 500, 1 nm wide bands. Even using 3 colors to emulate white, you would still need about 150 lasers. Good luck finding a laser for each wavelength with a tuning of 1 nm. I have seen PhD being made on tunable lasers, but not in the range of powers you are interested in. And I am not mentioning the difficulty of compensating for the different diffraction of each wavelength. [![enter image description here](https://i.stack.imgur.com/kgZ79.jpg)](https://i.stack.imgur.com/kgZ79.jpg) Beam can be slightly angled, but the closer to 90° the better.: a satellite normally circles the whole planet in about 90 minutes. It covers one degree around the vertical of a given spot for 7 hundreds of a second. Spy satellites can get that sort of control, but they don't aim for an object the size of a watermelon (with all the due respect for your head), though they can resolve it in their images. equipped with a powerful laser: last but not least, what makes you think that it is smart to stand under the shine of a laser powerful enough to shine through more than 100 km of atmosphere? Unless your goal is to impress the bystanders with the laser burns that you will get. [Answer] ## Stage spotlights Another solution that could accomplish this on a budget is simple stage lights. You can purchase a semi-decent stage spotlight for around $100. You have \$100 million available, so you could buy a million of them (or slightly less to account for the price of installation). But let's say you just buy 100 lights, that should way more than enough. You can then use the rest of the money to employ teams of electricians and lighting technicians so that whenever you know or think you're going to be somewhere, you send them in advance to install spotlights onto the side of buildings or whatever. If you know you're not coming back to a location for a while, they can then remove them and move them elsewhere as needed. Benefits over other suggestions are: * Way easier and cheaper than satellites and not subject to cloud cover * Not as noisy as drones, little to no risk of being shot down or stolen * Supports local economy wherever you go, provides jobs for electricians * Can also work for indoor appearances ]
[Question] [ Background Vampires are the usual sort. They sleep in coffins during the day and awake when it gets dark. Apart from the normal ways of killing them, they are immortal and so, despite their thirst for blood, they will never starve to death. Currently there is a plague of vampires and although they could be killed by the usual means, it is decided to try and make use of them. The setup A vampire lies in its coffin. When light ceases to leak in under the lid, the vampire awakes. It lifts the lid and sits up. However the lifting of the lid operates a mechanism such that, after a short delay, a bright light becomes visible. Seeing the lamp, the vampire quickly retreats back into the coffin and pulls the lid closed. This causes the light to be hidden. The sequence repeats indefinitely. A crank mechanism attached to the lid operates some machinery and so the vampire's ceaseless movement is converted into useful work. Problems There is no piped electricity or gas at this time, so lighting a lamp with a delay might be difficult to implement. Also, lamps bright enough to simulate daylight would be very hard to make. Assumptions There are plenty of vampires to experiment with and banks of coffins would be possible. Vampires can survive under moonlight and when subjected to a dozen or so candles. Above this level, the brighter it is, the faster they move to avoid it. Clockwork is well understood. Please ask for clarifications before answering. Question How should I design the setup to efficiently harness the movement of coffin lids? How does the lighting interact with the motion? Rough diagrams depicting the machinery will be welcomed. --- EDIT I specifically want the power to come from the opening and closing of lids with vampires popping up and down. Mainly this is for dramatic effect. I'm not looking for radically different methods. [Answer] This is a variation on [abestrange's answer](https://worldbuilding.stackexchange.com/a/195907/21222) that allows for a more compact setup. 1. Find a living author that is very popular worldwide. 2. Vampirize them and put them on a coffin. 3. Run a stake through the coffin so that it impales the vampire vertically. The stake connects to axles outside the coffin. Be careful to avoid the heart of the vampire, or use a metal stake to ensure you don't kill the vamp. 4. Have an idiotic friend that has never read that author's works write plays based solely on their titles. As seen in [Dresden Codak](http://dresdencodak.com/2010/06/03/dark-science-01/). [![An explanation on how to generate energy from dead authors: make their corpses spin in a thanatropic generator.](https://i.stack.imgur.com/vXsSH.png)](https://i.stack.imgur.com/vXsSH.png) [![The equations for the thanatropic generator: Spin = Audience size times (author's renown + defamation of works) divided by skeleton weight](https://i.stack.imgur.com/DsX8c.png)](https://i.stack.imgur.com/DsX8c.png) [Answer] # The coffins should spin on axles 1. The coffins should have as high a mass as possible to maximize the rotational energy gained by opening and closing the lid, but not so high that the vampire is unable to open it. 2. When the vampire is asleep with the lid closed, the coffin should be upside down, when the lid opens this will rotate the entire coffin along with anything connected to the axle. 3. Above the coffin, it will be well lit, either with daylight or other continuous light sufficient to cause the vampire to retreat and close the lid. But when the coffin is upside down, the light will not penetrate under the lid causing the vampire to awaken and open the lid again. 4. The inertia of the coffin and axles will be calibrated to allow for the coffin to rotate to the down position after the lid is closed. Some experimentation will be needed to get the timing right. 5. Flaps are installed to block any light getting to the lid while it is in the down position. This arrangement solves the problem of switching the lights on and off, as the lights are on all the time, and daylight can be used when available. [Answer] It seems like coffin lids are perfectly shaped to be hooked up to bellows. That has the advantage of being a source of power your society might be familiar with. If nothing else it could be used to keep the forge's fires burning. Bonus points if they use it to power an organ. [![Vampire Down](https://i.stack.imgur.com/7kmEh.png)](https://i.stack.imgur.com/7kmEh.png) In this first image, the vampire is in the coffin, and the fires of the forge have gone down some. The vampire will then rise up: [![Vampire Up](https://i.stack.imgur.com/Zm1WW.png)](https://i.stack.imgur.com/Zm1WW.png) This collapses the bellows, blowing air on the fire for our blacksmith. As you pointed out in your comments, this also lightens the room, scaring the vampire back into their coffin. When the fires go down again, the room will dim and the process can repeat. This can be scaled as needed by adding additional forges/coffins. Just don't run out of forge fuel! Or, as others have said, make sure the lid can't open enough for the vampire to get out. [Answer] Chained vampire coffins. It takes a finite amount of time for a vampire to rise, so if you have each coffin close a flap exposing the next coffin to the light, you can generate any delay you like by adding sufficient vampires to the chain. Then for the last vampire, make it so that the flap is exposing the next coffin to the sun when the current one is not exposed, and you will have a metastable system of the vampires slowly rising in sequence. At this point you can use a slider crank linkage attached to each of the coffin doors to get a rotary motion. [Answer] This is about the last way I'd use the vampires to create power, but if you do it this way you need your vampire to push on the lid of the coffin as hard as it can. Perhaps some prompting from behind would help, so let's have a little light inside the coffin to make it feel not so at home. Then a bigger light outside the coffin to return it. Both lights are powered from the same source, fed by a constant stream of acetylene from water dripping on a pile of calcium carbide, if you have that. Barring that, you tap into a mine with flashdamp. Anyway, the gas flows into a bifurcated metal tube that contains a gutta-percha segment. When the coffin lid is closed, it compresses that segment enough that the gas flows faster down the smaller bore segment into the coffin, at which point the flame burning there bulges further out in a metal lantern housing until it becomes visible past an opaque barrier that otherwise blocks the vast majority of its light. When the lid is open, the gutta percha segment is released and a larger quantity of gas flows out into a similar lantern outside. As for the lid itself, it serves as the escapement of an immense quality timepiece, the gearing of which permits its immense hour hand to exert prodigious force for lifting the monuments of your civilization on a predictable schedule, or more likely, for the purpose of periodically pulping the dissidents against your regime whom you have converted into vampires for final disposition. [![enter image description here](https://i.stack.imgur.com/KxaQS.png)](https://i.stack.imgur.com/KxaQS.png) [Answer] The setup is really simple. [![enter image description here](https://i.stack.imgur.com/SguHO.png)](https://i.stack.imgur.com/SguHO.png) The coffin simply has a lip that blocks light from leaking in until it is high enough, and a hinge so it falls back the right way. A large array of such coffins can be arranged around a single bright light source. Lenses can also be used to increase the intensity (if not the total light), focusing on a peep-hole or notch that is exposed when the coffin lid lifts high enough. Such lenses can use the light source more efficiently by wasting less of it on lighting the parts of the coffin that you don't care about, allowing more coffins to be controlled by one light source. Experimentally you can determine the intensity of light in a crack required to make a vampire close the lid. In the event of light failure, ensure that the hinged lids cannot actually open enough for the vampire to escape. When the light fails, the vampires will try, bash the lid against the top, and generate a horrible constant banging noise. This results in a vampire engine that produces more noise when you throttle it down. [Answer] The most direct way to translate vampire-power into usable power is by getting them to rotate an axle. Have the vampires toil away inside a large hamster-wheel that drives a horizontal axle, or have a vertical axle that the vampires spin by pushing on spokes and walking around in circles. The second one is how we harvested livestock-power to operate mills, the first was how we harvested the power of flowing water with water wheels (but the water ran on the outside, vampires will run on the inside). Even if the vampires are magically tireless, they still get hungry. So only vampires that work get fed. If they refuse to work, then they remain locked in their dungeon without food until they do. If they cannot be persuaded by the carrot, then threaten them with the stick. Not rotating the axle will cause a hatch in the ceiling to open, exposing them to sunlight. Edit: Night time wouldn't be a problem either if we assume they don't much care for fire. A roaring fire next to / above the hatch would likely suffice to keep them motivated. You do not have to waste fuel keeping it going at all times, just when your mill decides to get lazy. [Answer] My answer is I think a little mechanically simpler and more historically motivated than others, but forgive me if there is too much overlap with other solutions. I'm going to highlight these two lines you wrote: > > Also, lamps bright enough to simulate daylight would be very hard to make. > > > [...] > > > Vampires can survive under moonlight and when subjected to a dozen or so candles. Above this level, the brighter it is, the faster they move to avoid it. > > > I don't think that this first part is too big a deal. Since bright light sources are difficult, but the intensity of the light does not impact the effort the vampires put into opening the coffin, I would just try and harvest power from the opening of the coffin, not the closing. My suggestion is to attach the hinge to a ratchet, such that the opening motion will drive a gear, but the closing motion will do nothing. This gives you a gear pointing upwards that intermittently rotates a quarter turn in one direction. Because its on a ratchet, its okay if the mechanism keeps rotating (due to other vampires, inertia, etc) because the ratchet will keep the motion from opening the door. I would recommend using this gear in two ways. One would be to drive a timing mechanism that covers and uncovers a light at the maximum rate a vampire can sustain (remember that it can be relatively dim, so the bare minimum to make it retreat is fine). The other would be to connect it to a speed reducer. I would also connect the entire bank of vampires to this reducer. Then, I would use that reducer to drive a pump or a lift. Based off of the time period you indicated, it would appear that the primary use for stationary engines would be along the lines of a pump or lift from removing water/materials from mines. [ie James Watt's engine](https://en.wikipedia.org/wiki/James_Watt#First_engines) [or its precursor the Newcomen engine.](https://en.wikipedia.org/wiki/Newcomen_atmospheric_engine#Development_and_application) If your vampires will use their arms to push the door open and closed, you could even strap them into the coffins around their chests. That way you could make relatively compact bundles of coffins and time them with a 1/4 offset to get continuous power output from a shaft that runs through the centre of the bundle, and then you could orient the bundle however you wanted. You could use this to drive handcars, etc. Finally, you said that they never tire, so you may not care about thermodynamic accuracy, but the easiest way to use them if you do decide to would probably just be to burn them, rather than reloading coffins over and over again. [Answer] # Simple Lightsource: The Sun! Perhaps this system can be simplified significantly if the energy is only harvested in the daylight. Either use a system of mirrors and a trigger correlated (and delayed) with the opening of the lid to allow light into the room, or simply tie the lid to a larger door in the ceiling. At night, simply go around and lock all of the closed lids. I like the element of risk this poses: reminds me of nuclear power plants. You're playing with a dangerous energy source, and so there's a risk that if your attendants don't properly manage it, a "meltdown" (read: prison break) might occur! Think about solar power: you don't get anything at night. You store the energy! In point of fact, the largest battery holding solar energy in the world is nothing but a giant man-made lake! The energy harvested goes into lifting water into the raised lake. When you want to take energy out, you allow the water to flow downhill and turn a turbine. Easy-peasy, especially for your clockwork-savy folk. My thinking about harvesting the energy from the coffin lids: * It's likely simplest to harvest the energy from the lids as they fall rather than as they rise. Think about a pulley turning a crank with a one-way ratchet (like the rear gears on a bicycle or a ratcheting socket wrench [Edit: Just saw Mike Serfas had the ratchet already.]) and freeweight so it is unconstrained when being lifted. The line stays taught when the coffin is being lowered due to the freeweight, lifted again when the axel turns the other way. * People are right about heavy lids. Gravitational potential energy is $P = mgh$, with m - mass, h - height, and g - gravitational constant. Things are slightly more difficult to calculate precisely if the object is rigid, extended, and rotating, but the principle is the same. This is the same principle by which the aforementioned lake stores its energy. * If you want to get technical, you can consider the size of your pulley: this might make things easier efficiency-wise if you need a large amount of torque in the immediate application. Bigger pulley = more torque. The same thing can be applied through a series of gears with varying ratios between the number of teeth, but then you're losing some extra energy in friction. Source: Physics PhD student who clicked a cool sounding link on the side of Math StackExchange... ]
[Question] [ Long before you get to using fire to smelt metals, hammering is a much more fundamental requirement for basic technologies. Hammering lets you 1. Flake stones to make stone tools 2. Process food--grinding grain, cracking nuts, cracking shells, tenderizing meat, etc. 3. Construct things--e.g., using thorns as nails (a thing which Colonial-era Americans actually did). 4. Even work metals--e.g., cold-working native gold to make jewelry. Lots of animals use hammering in air. Woodpeckers hammer their beaks into trees. Birds will smash snails on rocks, or lift things into the air and drop them. Otters actually use rocks as tools to smash seashells. And of course, humans are particularly good at precision hammering with our unique arm structure. Underwater, though, the only animal I can think of that uses hammering is the mantis shrimp. And it's not too hard to see why: swinging things isn't particularly efficient with all the drag that water exerts, and dropping stuff to exploit gravity for enhancing your hammering runs into the same problem. So, how might one design an effective hammer that could be used by, say, a particularly intelligent stone-age octopus, or mermaid? Or, alternately, how might you have to design a sea creature to be good at hammering, without hyper-specializing it just for that task like a mantis shrimp is? [Answer] That would be not a hammer, but an axe. Stone age hammers and axes did not differ much, and in most cases were both - depending on the side you used (this is still the case for "civil" axes). An axe has a very aerodynamic (hydrodynamic) form and can be easily used underwater. And it was and is used underwater by divers where a knife is not enough (like cutting thick ropes) Axe is the most universal tool developed by intelligent animals - you can utilize it for any "simple" technology (with less efficiency that special tools) - from killing (hunting) to artworking. It is easy to invent and construct. For heaver hammering intelligent octopus would use a (metal) rod. It would allow the tool to have a lot of mass for its cross-section, so drag is not a problem. [Answer] Since your setting seems to be pretty primitive, thus not making highly advanced technology an option, I think we can look to nature for possible alternatives to hammering. An apt answer (similar to another answer by user V.Aggarwal here) that can be found in nature is the pistol shrimp. The [pistol shrimp](https://www.wired.com/2014/07/absurd-creature-of-the-week-pistol-shrimp/) has a special claw that lets it snap its claw so incredibly quickly that the sudden displacement of the water at the end of the claw causes that water to evaporate instantly, briefly creating a bubble made of water vapor. This bubble then collapses almost immediately due to the surrounding water pressure. This implosion in turn creates a (comparatively speaking) *powerful shockwave* capable of outright killing or knocking out the shrimp's prey. An interesting fact is that *pistol shrimps also use their ability to drill into solid basalt rock, little snap after little snap, in order to dig a burrow.* Assuming your creature knows about this phenomenon, it could try to develop a tool or natural appendage similar to the pistol shrimp's, or domesticate and then breed pistol shrimps (which are prettty tiny) in order to make them into larger and larger species over generations until they are big enough to be substantially useful. [Answer] A Vacuum hammer Not exactly a vacuum hammer, but one that uses its principles to operate. There is a certain fish that preys-on using these principles (I forget its name). It simply opens up its mouth wide and quick enough that the surrounding water along with the smaller fishes in it, storms into its mouth with astonishing speed. Your creature can use similar principles to create a hammering effect. Assuming there is a hammerhead and an object that needs to be hammered, create a vacuum between these two such that they collide. How to create that vacuum is something I haven't figured out yet, but something like this may work: A long hollow tube, having the hammerhead tightly packed at one end like a bullet inside a gun barrel, and the object placed at the other end (This end should be watertight), The tube suddenly expands creating a pressure difference and the water above hammerhead rushes inside, pushing the hammer towards the object and smashing the two. Hope this one gives you a slight idea. [Answer] Use water at your advantage, with a focused shock wave. Having water a very low compressibility, any pressure you give it will be transferred to the other end. If you focus the pressure wave you can deliver quite some energy, reaching the same result of a hammer hit. ]
[Question] [ This question already has answers here: [Is the location of major cities deterministic?](/questions/33748/is-the-location-of-major-cities-deterministic) (6 answers) Closed 6 years ago. Question: On what "factors" is the location of any (non-)fictional city actually based? Background Information: * I'm actually trying to get all logical/physical choices to generate a random World. * Assume that all cities are grown from villages and were founded "When History Started" or "At The Beginning Of Time". [Answer] Hello and welcome to WorldBuilding :) Your first question on this site is very interesting. While your question resembles the ones mentioned by Molot, it is not a carbon-copy of them, and indeed deserves a thorough answer. Prelude Your limitation of the time period (at the start of civilization) in your question is very important and it is this which also makes it all the more interesting! This means that those people would have none of the modern (or even medieval) technology available to them and would have to choose only those locations which are naturally suitable for large scale settlement. 1- Water! Freshwater is the most important factor in selecting a location for settlement. If you observe the location of all ancient cities, you will notice they were all built on the banks of rivers or lakes. The reason is simple: due to the lack of technology, those people were not able to dig out wells and were limited to settling on locations where fresh, drinkable water was amply available to them. So, as a starting point, we mark all the banks of rivers in your map/world as the potential locations where the nomadic people would think about settling down permanently. 2- Food You cannot live by water alone. Of course you are going to require food, too. When you mention at the start of historical times you are referring to a time when agriculture was beginning to develop. Being located near riverbanks would definitely provide you with a permanent resource for drinking and irrigation, but what about the soil type? Of course you cannot settle down at a place where water is amply available, but the soil is infertile and there is no prospect of agriculture or securing enough game to feed your people. So, now we eliminate all those locations near the riverbanks (and lakesides) where the soil is infertile and the region is barren and lacking in wild game. Only the regions which are fertile, or those having large game reserves would be suitable. 3- Natural Disasters Would you want to settle down in a place which lays on a geologically active fault-line? Definitely not! The city would be destroyed within a few decades, or a couple of centuries at most. What about a region which is home to intense tornadoes or cyclones? The same. You would not want to settle there, even if it was very fertile and rich in wildlife. So now we limit our locations to the riverbanks which are fertile and are not home to severe natural disasters such as earthquakes, floods and cyclones. Of course an earthquake or a storm would ravage the place once in several centuries. The region just shouldn't be in the bull's eye for such calamities. 4- Lifestyle Finally, there is the issue of lifestyle and preferences. If you belong to a hunter-gatherer culture where only few people are inclined toward agriculture, you would probably prefer settling down on a riverbank where wild game is available in excess, even if the soil is not very receptive for agriculture. Similarly, for an agricultural-minded people, a fertile plains region would be more preferable to a savanna teaming with game. [Answer] Next to a river is always a good place to start an inland village (which may sprout into towns and cities). Many cities in Europe and Central Africa are founded along rivers. There are numerous benefits to this, among others: * The soil around rivers are more fertile due to regular flooding * Rivers provide a more constant source of fresh water * Rivers have benefits for productivity (using boats for transport of goods or building water mills) Caution should just be taken for flooding, and adverse conditions upstream may have detrimental effects, but in general, rivers are good places. Coastal cities such as Cape Town were often founded as halfway stops for long sea-expeditions, like the East India Company, to rest and restock. Food resources along the coast will be more prominent as there will generally be fish and more potential fresh water. Mountainous terrain may provide refuge to people who will otherwise be vulnerable to vicious animals or stronger rival civilisations. In South Africa we don't really have any prominent rivers, so the motivation for settling was different. Disregarding the long history of people moving away from Cape Town due to political reasons, Johannesburg started out as a mining town since we have quite a lot of gold here, so people moved here after the potential money. More north of Johannesburg we have platinum (Rustenburg) and coal even more north and diamonds in the Northern Cape (Kimberley). Pretoria is kind of in between the platinum and gold. It's away from the dirty mining business but still close enough to reap the commercial benefits. (Sorry for the strongly South African references, but that's what I know well). These may be more modern reason's for setlling, but I still think it's valid. In fact, villages originally in these areas may have a greater advantage in modern times and thrive as cities with these resources. To summarise, you can have your people settle close to: * Fresh flowing water, and if that's not possible * Generally more humid areas, * Mountainous areas. * If you'd like a more modern twist, let them settle near valuable resources * And then just for some randomness, have a small chance that cities may form in less hospitable areas like deserts. (There are people surviving and thriving in arid, hostile conditions. As Mrkvička suggested in the comments, the conditions may have been conducive to a thriving civilisation but deteriorated slowly enough for the people to have adapted) This is not exhaustive but I hope it helps. P. S. A good book to read is Guns, germs and steel by Jarod Diamond, discussing a lot of reasons why civilisation came to be as it is. [Answer] Cities typically grow out of trade. Some genesis points: * Ports - Towns with safe harbours that are convenient for overseas trade to arrive will grow with the incoming and outgoing trade. * Fords - Towns that grow up where trade routes cross a major river. These are natural stopping points and act to compress trade routes in one place * Cross-roads - Again, these are compression points for trade routes * Religion - If something significant has happened, a town will grow up around that area Basically, anywhere that groups people together with a need for them to stay together for a period of time or for a purpose. The greater the demand for people, the larger the town becomes. [Answer] There is a wonderful Youtube video by Wendover Productions that explains [why cities are where they are](https://www.youtube.com/watch?v=3PWWtqfwacQ). A summary: * Towns are usually 10-15 miles apart, because you can walk about five miles, go to a market, and walk about five miles back in a day. * The distribution of settlements is related to the sphere of influence of the settlement * The distribution of larger towns is more sparse than towns, and cities more sparse yet * Cities are located near water, either ocean or river, to facilitate trade * Cities are located near natural resources * Mountains have varying effects on settlement locations, as they can hinder development, but also be a source of natural resources, and provide protection for cities * Continental features are important - wide continents may be much better for human development than tall continents, given that the climate is similar throughout it, and that cultivation of certain plants can be done more easily I highly recommend watching the video itself. [Answer] Ok. A lot of people have covered most of the important things, but let me point out a few more. Historically speaking, there must be a reason that the camp that became the village that turned into the city was put there/stayed there. Also, the settlement needs to have survived for a long time to grow that much. # So, let us start before history began, and the people were still nomadic hunter-gatherers. These hunters went from place to place, hunting and gathering. They might have been looking for a good place to stay for winter, and found a spot where there were some good natural options for making some shelter (such as caves, a forest, or a good place for finding rocks), a good water-source (such as a river, stream or lake), and preferably a food-source (such as fish) that won't need them to go on long trips to refresh the store next winter. Remember, they have their wives and children with them, so they don't want to traverse unknown, dangerous terrain. They want a nice, friendly place. So, after finding a good place, they settle, and start a village. It is a good place, so others want it too. That means that the first settlers (or the second, whoever thinks of it first) needs to fortify it. Meanwhile, the food-source needs to be able to feed the villagers (who are now experimenting with agriculture). If the fortifications are too hard to make, the village will probably be abandoned. As agriculture develops, the strain on the single food source relaxes, and the village is no longer threatened by starvation. # After a while, when everyone has settled down, someone comes up with the idea of trading. Thus begins a whole new set of challenges for our people. They need to trade. Not only for food, they probably have a lot of that, but also so that the neighbours don't look over and say "hey! they have all that stuff they don't need, let's go and take it of their hands" starting a war. And as everyone wants the stuff they are sitting on (be that clay, fish, herbs or ornamental stuff) everyone teams up against them, so that they can trade for that ware with whoever gets it. Also, trading brings allies. Allies mean strength and more people to do inventing, which means that you develop faster. Allies mean that your daughters can go and marry someone who is not their second cuisine for a change. This is a good thing, because intermarriage leads to all sorts of genetic diseases. Eventually, these allied villages will decide that it is easier to take all their wares to one spot, which is close to all of them. This will become an early market, or a town centre of sorts, as people realise that if they move there they will get more custom for their wares and services. As the small community prospers, it grows. As it grows, it creates a sort of economical vacuum where everything and everyone goes. Some people realise that they need better defences, and build some city walls. Others become more powerful, and a sort of government develops. I think that is roughly all I can say, hope it is useful. [Answer] Trade routes. As long as as there is good communication, the best place to be is on the easiest route connecting two or more major population centres. Merchants going both ways benefit from a safe place to rest and resupply, and the opportunity to make a sale without having to travel the whole distance. This is especially important if the area is otherwise inhospitable, e.g., little water or forage, or possible bandit attacks. ]
[Question] [ The notion of using the so called [Stanford torus](https://en.wikipedia.org/wiki/Stanford_torus) to generate artificial gravity is well known, but once you build the mega-structure how do you make it start rotating? Do you rotate somehow from the center, or do you install booster rockets on the circumference? Also, given the structure is in space, is the energy required for rotation a one time expenditure? Or will friction come in to play and multiple periodic boosts would be required? [Answer] Considering that to make something rotate you need to apply a torque, and that the torque momentum is given by the applied force times the distance from the rotation center, it makes more sense to apply pairs of booster rockets on the outer circumference of the torus. Think of spinning up a bicycle wheel: is it easier to do so grabbing it from the tire or from the axle? Over time internal losses will slow down the rotation of the torus, and you will use those rockets to boost it up again. But my gut feeling tells me it's not something you will doing very often. [Answer] The construction of a rotating space habitat isn't particularly well defined, but acceleration would be required. Here are a few considerations. ### Superstructure Initial construction would be performed as a zero-G operation, simply because it would be easier to place objects and bolt/weld them together when they aren't trying to fly away. Once the superstructure was in place, it would be accelerated to low G because, if you have a floor, a tiny amount of gravity keeps things in place. Plus there's the reality that you'd want to test all of the connections before you attach billions of dollars worth of equipment to it. Initial spin-up would be a major milestone in the construction. ### Pressurization and full spin-up There's no point to higher G's before you have an atmosphere, so you'd want to spin it up to final rotational speed some time after pressurization. On the other hand, everything you load aboard will add to the energetic cost of spin-up, so you'd want to do it before you start filling it with objects that might shift around. A cautious engineering group would spin it up gradually so they could monitor the joints under increasing load, and correct any problems as they crop up. ### Alternatives for adding spin There are numerous methods for spinning up a two-kilometer wide disk, depending on how quickly you need to do it. You have to consider that the whole thing wouldn't be rigid. Think of the station like a big, spinning Golden Gate Bridge. You couldn't drive spin from the hub because it would twist and pull on the supports and create a resonant bouncing. This configuration makes flywheel compensation more problematic. If you just hooked up a single ship to one side and turned on the thrusters, it would twist, compress, and yank on the primary hull. Attitude jets would be necessary to adjust for mass shifts, so that's the simplest solution, but also the least energy efficient. It would be more likely that someone would think to use the construction ships like tug boats. A construction of that scope would need a continual influx of materials, so you could engineer a mechanism where each incoming shipment were caught to add a little bit of momentum to the spin. The alternative would be to slow the shipment's speed down to nothing, importing it at the hub, then re-accelerating it when you move it to one of the rings. That process would require continual addition of acceleration every time you moved a wall segment in, just to keep it at the same speed. You could use solar sails to adjust speed over time. I'm imagining they might set them up like an insanely huge pinwheel. You could slingshot mass past it while shipping materials around the solar system, or radiate waste heat from industrial processes in the right direction. You could install launchers to fire finished goods or waste materials from the station, using those as reaction mass. ### Maintenance Chances are, they would do all of those things and balance them out with an accounting system. There is some question about how much small adjustments would matter. The base Stanford Torus design calls for about ten million tons of mass, so something like moving a cargo container from the hub to the rim would be unnoticeable to humans. If you had scientific or manufacturing processes that you didn't want to jostle, you'd probably want to set up a train that constantly circled the torus. You could load and offload with segments that matched speeds, and use the train's speed to counteract the small adjustments in the station's rotational moment. ### Friction? There is no meaningful friction to spinning in place in outer space. Even in a nebula, it would take millennia before you could measure a difference. [Answer] Possible alternative solutions. * Have more than one torus: The central hub would be used for docking as in other solutions, but at each end would be a hub with spokes radiating to a torus, giving you two habitats with gravity and the "axel" for zero g activities. The hubs can be spun-up by applying torque clockwise to one and counter clockwise to the other using electric motors, to prevent the nasty effect if one torus has more mass than the other making the axel spin, that can be balanced out by raising and lowering weights inside the spokes to trim the angular momentum. Spinup thrusters would not be needed. * Triangular pyramid. Another alternative would be to have a longer axel in tetrahedral formation, allowing for four habitats, and allowing for easy reorientation of the station through differential slowing/speeding-up of the rotation of the tori - transferring some of the rotational momentum to the axels as desired. This would require initial "clamping" of the axel with station keeping thrusters to prevent tumbling during spin up. [Answer] The station should simply continue rotation if nothing disturbs it. Disturbances might come from spacecraft docking with the station or from the unbalanced movement of masses inside. Momentum would be preserved, so there could be effects like a [figure skater](https://en.wikipedia.org/wiki/Angular_momentum#General_considerations). Because of that, I would expect rocket engines on the outer rim. There may also be gyroscopes, to compensate for small changes without expending reaction mass. [Answer] ## Gyroscopes Initial spin-up might be assisted by rockets, but fine adjustments would likely be accomplished with gyroscopes on the central axel that spin in the opposite direction. Unless they were truly enormous it would take a LONG time to bring the station from stand still to full rotation, but spinning the gyros would cause the station to rotate in the other direction. The change would be fairly small, but since friction would be minimal, most changes to velocity would be from movement within the structure and ships docking and loading/unloading material and once spinning at final velocity minor corrections in either direction could be accomplished with fairly small (comparative to the structure itself, they'd likely be car sized or larger) gyroscopes. [Answer] Since you are asking specifically about a Stanford Torus, not just any old toroidal rotating space station, why not just look at what NASA SP-413 "Space Settlements: A Design Study" (i.e., the document which describes the Stanford Torus design and construction plans) has to say about it? Surprisingly, it doesn't actually dictate a specific spin-up method--only that the pressure hull and shielding should be completed first, so that spin-up can occur as soon as possible to make interior construction easier. However, it does mention a spin-up method: > > If the shield is used as a reaction mass during spin-up of the torus it would counter-rotate at approximately > 0.07 rpm; the relative velocity between the shield and the torus, would thus be about 100 m/s. The torus is prevented from scraping against the shield by a positive positioning device. > > > So: just use electric motors to drive wheels to react against the exterior radiation shield, which is designed to be far more massive than the habitation structure. Then the net angular momentum of the station remains zero, and controlling the spin rate to account for internal movement and additional of materials during construction is easy. [Answer] There are two parts to this that I find interesting. First: > > once you build the mega-structure how do you make it start rotating? > > > There are many options for this including - but certainly not limited to - equatorial thrusters (in balanced sets of course), counter-rotating weights or paired torii, even balanced solar mirrors providing torque. Personally I like the idea of building two torii next to each other, spinning them up in opposite directions then separating them once they reach operational velocity. That way you get two spin-ups at once and twice the habitat space. The more interesting part of the question though - at least from my perspective - is the second half: > > Also, given the structure is in space, is the energy required for rotation a one time expenditure? Or will friction come in to play and multiple periodic boosts would be required? > > > Even if you were building your toroid in one of the inter-galactic voids, friction will be a thing. The closer you are to a planet or star the higher the density of particles in the surrounding volume, and thus the higher your friction. We can mitigate this slightly by building very smooth outer hulls and so on, but you'll never eliminate the drag caused by rotating in an imperfect vaccuum. It's not just the friction you need to balance against either. Every time you bring something onto the station, and every time you take something away, the rotational speed of your station changes a tiny bit. Lifting a mass from the 'surface' to your center of rotation will speed up your rotation, bringing mass down from the center to the surface will slow it down. You'll need some way to account for those variations when they are large enough... but as long as you're not moving large masses around you should be fine. You'll probably have more issues with balancing the spin when mass distribution changes. And of course there's the issue of gyroscopic precession and tumbling. Anything that produces unbalanced thrust against the spinning station could produce unexpected forces. That's another argument for counter-rotating pairs, I reckon. [Answer] It would seem that any large scale station or habitat would have a thruster network anyway in order to maintain its orbital position. Depending on the orbital position of the Torus, such as at certain Lagrange points, station keeping thrusters would be required for orbital corrections and maintenance. You could use these thrusters to provide the initial spin for the station. [Answer] I’m issuing a frame challenge to the seemingly practical idea that the torus needs to be started at all. Intuitively, we see the problem as two steps: Build torus, spin torus. This is where reality and common sense diverge. Let’s consider spinning a flywheel made of bolted/riveted parts that is 2.2 miles wide and has a mass of 10 million short tons. There is simply no technology that can give this thing a smooth and steady push up to 1 RPM, nor is it possible to keep it from tearing apart as you push it from a few points. You need to distribute the thrust over thousands of points, with a slow and steady thrust maintained for years. So, after my own experience in the St. Louis Arch Nations Park, that construction led me to realize that the force of gravity which everyone saw as an obstacle was leveraged to bring the curves together in a very practical way. The same principle applies to your torus, which is simply an assembly of several arches under centrifugal force, when spinning. The intuitive “static” construction brings many variables, and many opportunities for failure once it’s spun up. Reality has unintended consequences that won’t ever show up on paper. Definitely not for such a novel engineering feat as this. So the solutions is to keep the environment constant, never introducing the variables of spinning it up. How? You begin building the torus at the hub by very simply spinning the hub components, with crane rigging on it that will be removed later. Spinning has no effect on your orientation in space unless you at at the axis of rotation, in fact it provides and orienting “downward” force to facilitate work. So workers will move outward along the spokes while the assembly is already spinning. Construction is worked on each spoke simultaneously, having components given their initial matching spin, then delivered to the hub, and lowered down the spoke by the central crane system. During the difficult periods of construction, as the crews get further down the spokes, they can actually sit and take breaks. They can rest their tools on a platform (still tethered, obviously), and work in a much more comfortable environment. As the construct gains mass, synchronizing work on each spoke becomes less important, because the components will be a smaller fraction of the whole mass. I imagine 5 meter sections of spoke tube will be mass produced, delivered to the hub, and lowered to the ends of their spokes to be simply bolted together. When the spokes are complete, they form a crane system to build the ring. Connect each spoke end by a taught cable, and bring your ring components out to meet in the center. You’re not adding any mass that isn’t already designed into it, nor are you worried about why might fly off once you spin it. No new forces are introduced. Alternatively - the spokes continue to serve as crane supports. Start with the center of each arc suspended by two spokes near the hub. “Lower” it toward the perimeter and add another segment. Lower, add, lower, add… until an arc is hanging between each pair of spokes, naturally pulling its curvature outward. Just connect them the the spoke ends. I guess the short answer to the question is, spin every part individually during assembly and don’t worry about the whole dangerous and unnecessary spinning evolution. You will only need small thrusters to occasionally maintain spin. ]
[Question] [ Say we had some type of four-wheeled vehicle on the inside of an O'Neil cylinder with roads. I imagine if it drove in the same direction as the spin, there would not be many problems. However, I am not sure what would happen if it were to drive down the length of the cylinder or in the opposite direction of the habitat's spin. If the vehicle doesn't behave like a normal vehicle on earth in these situations, would there be some sort of device that could make it? For instance, a smart speed limiter? Im thinking if cars would not work well, then vehicles locked into tracks would have to be used instead. [Answer] The [Wikipedia page](https://en.wikipedia.org/wiki/O%27Neill_cylinder) for an O'Neill Cylinder indicates that they would revolve at a rate of around 2.8 degrees per second – at a diameter of 5 miles, that would be a surface speed of about 0.12 miles per second, or ~440 mph. If the velocity of the surface is 440 mph, then ±40 mph would be about 90–110% of Earth gravity. Not enough to float, but probably enough to require a specialized suspension. (Edit: Note that the 1g ±10% is a rough estimate, see @TannerSwett's answer for more precise values) However, are cars on roads actually the most likely transportation method? At 20 miles long and 5 miles in diameter a typical O'Neill cylinder has 300 square miles of area (~775 km$^2$), which is the size of a small county in the USA (or about the size of Bahrain). Roads are mostly wasted space, if you are trying to grow food or house humans. Public transportation is most likely, and trains or trams, connected to a central electric grid, would not pollute the air. And, if you use vehicles on rails, then designing them like roller coasters would 100% resolve any issues with "falling off". [Answer] As long as your car stays on the same radius from the axis, it can do what it wants with very little effect. Driving north/south along the axis is exactly just driving on flat road. Driving spin/antispin will encounter an apparent upwards curve in the road, that the car somehow never reaches. Spinward will increase gravity a bit, Antispin will decrease it a bit. The amount is small though, driving antispin at 70km/h will reduce your gravity by only 18%, driving the same speed spinward will only increase your gravity by 21%. That is about the same as the acceleration felt when you are in grandma's car going shopping, and she pulls away at a green light. MAybe a third the acceleration of when she slams the brakes to avoid that nice kittycat crossing the road two city blocks ahead. The only time when driving a car in an O'Neill cylinder will get weird, is when the car drives up a ramp towards or away from the axis. Then coriolis effect will rear its ugly head and try very hard to throw you off towards the spin or antispin direction, depending on whether you heading towards or away from the axis. [Answer] [IronEagle's answer](https://worldbuilding.stackexchange.com/a/205085/7862) explains that the cylinder would have a linear speed of about 440 mph (708 km/h). Driving spinward or "east" (which is to say, in the direction of rotation) would cause the occupants of the vehicle to feel heavier, and driving antispinward or "west" would make them feel lighter. I've calculated just how much heavier or lighter they would feel at various speeds: \| Speed relative to floor \| Speed in inertial frame \| Apparent gravity \| \| --- \| --- \| --- \| \| 75 mph (121 km/h) antispinward \| 365 mph (587 km/h) \| 0.67 g \| \| 50 mph (80 km/h) antispinward \| 390 mph (628 km/h) \| 0.77 g \| \| 25 mph (40 km/h) antispinward \| 415 mph (668 km/h) \| 0.87 g \| \| Stopped \| 440 mph (708 km/h) \| 0.98 g \| \| 25 mph (40 km/h) spinward \| 465 mph (748 km/h) \| 1.10 g \| \| 50 mph (80 km/h) spinward \| 490 mph (789 km/h) \| 1.22 g \| \| 75 mph (121 km/h) spinward \| 515 mph (829 km/h) \| 1.34 g \| So, the occupants would definitely notice a difference in how heavy they feel, but not a huge difference. Cars may be designed to be somewhat sturdier than cars here on Earth, and there would probably be a note in the owner's manual saying not to drive spinward at high speeds while heavily loaded. Driving along the length of the cylinder would have no unusual effects. [Answer] The surface and car only move in reference to the axis they're jointly spinning around so as long as the car maintains surface contact it will behave as a car on Earth would. O'Neill cylinders are small enough that people could detect the difference in spinward/antispinward direction by turning their heads, without feeling sick or other I'll effects, so the influence on driving would be negligible. ]
[Question] [ I am working on a story where I will take the geography of our world but install new peoples, cultures and histories. This will likely include fantastical elements as well as mundane. In working through this I have started with the base topographical map of the location I am working through and then began to paint in the cities and states of the groups I'll be writing about. In thinking of where the cities will be located and the backgrounds of those places I begin to wonder exactly how much I will need to look to our own history as a guide. As geography is paramount to where we have settled and why we have settled there, in addition to often also framing the narratives we tell ourselves about those locations and in turn shaping the cultures that grew around those narratives, how much credence should be placed on the existing cultures and histories of our own world when using the geography of Earth as a template for a fictional peoples set in the same location? [Answer] Let's try some examples. * The Italians live in the exact same geography where the Romans lived. The Romans built a great empire which endured for a long time, and has greatly influenced legal and political systems throughout the world to this day. The Italians spent a full millennium divided into many small states waging funny little wars between them, and were finally unified by the House of Savoy, ruling over a principality which is now in France. When the Italians tried to [build an empire](https://en.wikipedia.org/wiki/Italian_Empire) they got [beaten by Ethiopia](https://en.wikipedia.org/wiki/First_Italo-Ethiopian_War) and Greece. The Romans were known as dour pragmatists, who looked down upon the artsy Greeks. The Italians are heavily inclinded towards art and entertainment, and are not exactly known for their pragmatic approach to life. * The geography of Egypt has not changed all that much since the days of [Eratosthenes](https://en.wikipedia.org/wiki/Eratosthenes) and [Ptolemy](https://en.wikipedia.org/wiki/Ptolemy) the Astronomer. Nevertheless, nowadays [Alexandria](https://en.wikipedia.org/wiki/Library_of_Alexandria) is not really among the [focal points of world culture](https://en.wikipedia.org/wiki/Category:Roman-era_Alexandrians). * The geography of Japan has not changed one little bit since the days of [Tokugawa Ieyasu](https://en.wikipedia.org/wiki/Tokugawa_Ieyasu). There is little similarity between the self-isolated country which stubbornly refused to engage with the outside world and the modern industrial hyperpower. * The geography of modern Germany is the same as the geography of the same territory during the Middle Ages. While for a thousand years the Germanies were divided into a bewildering patchwork of states and statelets, suddenly in the second half of the 19th century Germany emerged as a unified superpower with ambitions to take over the world, first through force of arms and now through engineering and technology. Geography is important. It cannot be ignored, and it cannot be circumvented. But miracles do occasionally happen. [Alexander the Macedonian](https://en.wikipedia.org/wiki/Wars_of_Alexander_the_Great) king transformed Greece into a superpower, albeit for a short time, but that short time was enough to [change the culture](https://en.wikipedia.org/wiki/Hellenization) of all the peoples from the shores of the Mediterranean to India. A tribe of Turkic-speaking nomads from central Asia took over the (Eastern) Roman Empire and ruled for half a millennium. A small, cold and rainy island took over large, rich and populous India, gave it a common tongue and made it into a united country. History is not predetermined. * Excursus: the foundation of Byzantium. The question states that "geography is paramount to where we have settled and why we have settled there". Here is a classical semi-mythological anecdote, which was transmitted to us by [Strabo](https://en.wikipedia.org/wiki/Strabo) the Geographer. In the 7th century before the common era, [Megara](https://en.wikipedia.org/wiki/Megara), a city located on the Greek isthmus, was in full colonizing mode. One of the their colonizing efforts was led by prince [Byzas](https://en.wikipedia.org/wiki/Byzas), officially the son of king [Nisos](https://en.wikipedia.org/wiki/Nisos), and mythically the son of Poseidon, the god of the seas. Prince Byzas went to the [oracle at Delphi](https://en.wikipedia.org/wiki/Pythia) to ask where to set the new colony. The oracle replied that he should establish a new city on the land "opposite the city of the blind". Byzas went in search of the city of the blind, but nobody had ever heard of such a city. As he sailed north through the Sea of Marmara and entered the Bosporus, he noticed on the western bank the [Golden Horn](https://en.wikipedia.org/wiki/Golden_Horn), which provided a magnificent natural harbor. Opposite the Golden Horn, on the eastern bank of the strait, was the small city of [Chalcedon](https://en.wikipedia.org/wiki/Chalcedon), an older Megarian colony. Byzas immediately realized that Chalcedon was the city of the blind, as only blindness could have made anybody establish a city on the wrong bank of the strait. He established a new colony on the western bank of the Bosporus and called it Byzantium. In time, the city he founded was to be renamed [Constantinople](https://en.wikipedia.org/wiki/Constantinople), and would get to be capital of two great empires; today it is called İstanbul and is the most populous city of Turkey. As for Chalcedon, it is now a district of İstanbul. [Answer] Geography has some influence on the culture of the people living in a certain region, though it is not the only force shaping it. Look at the USA. Without the vast spaces opening to the west, the Anglo-german colonists of the 13 colonies would have hardly changed their home culture into the one of the self made man. You can also see how the sports which are popular in USA (baseball, american football) are a metaphor of the slow gain of territory, while the european favored sports are more resembling a codified war. Or look at UK and Japan: without their insular geography, could have they thrived in their isolationist culture? It's a famous joke the headline of the English newspaper "thick fog on the Channel, the continent is isolated!". [Answer] 1) Our species evolved on the savanna and by standards of the animal kingdom, we're master long distance runners. Our brains have neurons connected much more than in other animal ones, give edge not only for abstract thinking but also for hunting animals by running them in to total exhaustion. Not sure whether you can change that for purpose of your story. 2) Our civilisation flourishes in interglacial period. Right now we're roughly in cycles ~120k years of ice age, ~20k of interglacial period. (Rough approximation, see [Milankovitch cycles](https://en.wikipedia.org/wiki/Milankovitch_cycles)). You may subvert that by having in your timeline to almost make civilisation in intergalciar period, fail it, and actually achieving hardly worked success in another ice age, just for practical purposes whole geography would be different. Extra bonus - because of wobbling of Earth axis, there are periods in which Sahara is more or less green 3) Our brains are still evolving. Especially at extremes environments - apparently cold winters are good for your brain, as such predictable cycles tend to eliminate the least fore planning members of one's tribe. Without this point is hard to explain that there are some differences in average brain size between ethnic groups matching this pattern. In our history it did not matter much, but there was another similarly suitable environment - it seems that Polynesians evolved too some edge in spacial intelligence and ability to keep direction. There is also additional suspected factor - seems that some civilisation tend to self reinforce themselves, by introducing harsh rule of law. From evolutionary perspective it means executing (thus eliminating from gene pool) the low IQ and high sociopath individuals. On the other hand is genetically undesirable if intellectual elites keep number of kids low (contraception, celibacy, etc.). 4) If you want to domesticate big animals, then better co-evolve with them. Even Jared Diamond points out that in Americas there had been horses and camels, just they were hunted in to extinction. Unless it's just a fluke, it seems that animals in Eurasia had a chance to co-evolve with us, so survived a bit longer to give us chance to domesticate. [TLDR: it seems that there were more species to domesticate.](https://history.stackexchange.com/questions/1095/how-accurate-or-supported-is-jared-diamonds-guns-germs-and-steel/54625#54625) 5) Civilisations tend to start in hot river valleys and spread to colder regions but they are to be trampled by nomads. Even if civilisation look impressive, the even more impressive thing is a group of warrior nomads, that are highly mobile. Ask neolithic Europeans and India peoples about Yamnaya, ask Romans about barbarians, ask whole Eurasia concerning Mongols. 6) Yes, premodern civilisations tend to produce superbugs. Regardless whether it's indeed issue of domestication of animals, or just a problem of close proximity and big groups of humans - it happens. So whatever there is, first your cities would be suffering from plagues (medieval European cities needed steady influx of people from villages, just not to get depopulated). Later, when you came in to contact with primitive, isolated tribes... let's say that your weapons are not their greatest problem. 7) It's a bit tricky to get different humanoid species. is a general rule - in long run two species can not occupy the same niche - whoever is even slightly less adapted, would be outcompeted. Ask Neanthertals or Denisovans. If you want to keep it realistic - some of your species should have a different and clear edge that works really well in some environments, but is detrimental in others. To be fair, some fantasy books (the original Witcher Saga) got around this problem neatly, as after some kind of magic cataclysm species from different worlds suddenly met, and is implied that humans are effectively highly effective invasive specie that already mostly exterminated elves. [Answer] ## There are a few powerful factors. Productivity: You are not going to have large sessile communities on unproductive ground, large cities require fertile ground and plenty of water just to keep themselves fed and watered. So what we call "civilization" (large populations, specialized labor, advanced technology) always start in places with high fertility and a good water supply, most of the time that means a river valley or large lake. Timber is also important for such societies, more than once advancing societies consumed all their local forests and fell apart, no wood means no fuel for cooking and almost no building material. Note however river valleys are not rare. Wildlife: what plants and animals are available has a strong impact, animals that can do work and domesticated plants that have a long shelf life (grains) makes for very powerful civilizations, it means large food surpluses and ease of travel for trade (or war) One of the big limiting factors the Inca experienced was war could not be sustained for long because they needed the labor for agriculture. This limited how far they could expand. You as the world creator have a lot of control over this one however. Ease of travel: The easier it is to travel the larger an society or empire can be, large states need to be able to communicate rapidly to persist, Often this is water based, rivers or seas, but flat plains also lend themselves to it. If communication takes to long you don't know what is happening on the borders soon enough to do anything about it and you start loosing land to rebellion and conquest. Egypt could be one large state because everything was within a few miles of an easily navigated river. Don't expect states to expand across harsh mountains or desert unless they have a coastline to follow around it. Islands: you would think islands would be good for societies but small and volcanic islands in particular run into a problem, lack of resources. I mentioned wood, but they also lack metals, water sources, and variety in organisms so island cultures tend to be doomed to limited technological development. Islands have to be very large (japan) or very close to the mainland (and thus on continental crust) before they overcome this problem. In short big communities and thus later big states always occur in river valleys if it is near the ocean even better, you shouldn't have large states is poor environments or springing from seemingly nowhere. The size of a community effects a lot of other things, but most come down to is there enough food surplus for specialized labor, and will the society exist long enough to exploit it. If you want a society to have technology, classical governments, social classes, or even just cities, they have to be in a place that can support them. One of the giveaways of a fantasy setting is a huge empire that somehow persists in wasteland. There are a lot of smaller factors too, many cultural differences (but certainly not all) originate in differences in environment or in unshared or unique solutions to said environment. But such a list would be well beyond the scope of a single question. At the same time a lot of cultural factors are completely unaffected by geography, geography provides more of a rough constraint than detailed prediction. [Answer] Culture is deeply connected to food. Just look at any culture you can think of and they all have dishes they identify as their food, owning it either by ingredients or the way ingredients are treated. Believes and traditions grow on to what first began as simple environmental conditions, providing certain food, disallowing for others. Geography forms different environments that allow for different plants and animals to dwell. Imagine a very dry, warm land, and how hard it will be to grow crops if water is sparse. People settling in such areas will mostly rely on livestock that is able to eat tough desert plants, and won't consume a lot of water. That is actually considered the origin reason why muslim countries don't eat pork: the meat of pigs does not last as long as goat meat, and pigs use more water. [Here you can read a good summary.](https://www.quora.com/Why-did-Islam-ban-eating-pork) So the conditions that geography provides are very much responsible for the cultures that develop out of it. Compare variety rich regions, which provide water, forests, plains and mountains in mild weathers full of wild life and the people will be healthy and happy to share what they have, to regions with unpredictable cold and windy weathers and only fish as their main source of food, and you will get folks with a harsher view on life. You are what you eat. Nowadays we are able to eat almost ALL the dishes humanity has come up with, but just a few hundret years ago (or even just a half century ago) that was only possible for very few people. Kings in the past did not nearly get the variety of food we get today. In times of hunger many farmers and their households would eat porridge. Only porridge. For breakfast, lunch and dinner, every day of the year. Keep that on for some generations and the culture which grows out of that, even when eventually some bacon gets on the table, will call their children to be grateful for what they have and demand to be considerate. The demands of circumstances will become traditions will become religion. [Answer] Geography in a society determines more than you think, in fact everything [Jared Diamond](https://en.wikipedia.org/wiki/Jared_Diamond), professor of Geography and Anthropology at the University of California, is a strong advocate of Culture linked to Geography, as outlined in his books [Guns Germs and Steel](https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel), and [Collapse](https://en.wikipedia.org/wiki/Collapse:_How_Societies_Choose_to_Fail_or_Succeed). Fundamentally, he asked himself the question Why did the Spanish invade the Aztecs instead of the other way around? The answer, he concluded, was all simply geography. He made a few points: * There is little to no difference between races physiologically. We have the same brain masses, essential genetic makeup and the same physical abilities. Therefore the reason cultures are different is due to only environmental factors. * Continent size and accessibility is a key factor in development. Europe and Asia had a wide, latitudinal aspect ratio, meaning climate was constant and physical geographical features were not impassible. This lead to the interaction of different peoples on the continent, pushing development, conflict and cooperation. In contrast, South America had varied conditions as it was a longitudinal continent, with impassable jungles and mountains, making interaction between cultures almost non-existent. * Geographical features influenced strongly food, crops and farms. In Europe, large areas of fertile soil combined with a crop (wheat) of high yield allowed cities to grow fast, and food to be easily cultivated. In contrast, South America had no such high yield crop, so number and size of cities were numbered. Also, mountainous terrain and jungle impeded transport, such that cities were limited to walkable distance from water holes, as opposed to Europe where towns were large, spread apart and wheeled transport allowed trade of goods. * Geography also influenced animal husbandry - Europe having wide geography with links to Asia and Africa, had species easily domesticatable and scalable. South America lacked any such animals. Australia also - kangaroos do not make containable stock being fast and agile, so Aborigines were unable to breed and cultivate them. Cows, horses, chickens and sheep however are easily contained and bred, and allowed large cities, trade and mastery of transport and breeding. In the end, culture is determined essentially by interaction. Jared Diamond offered the explanation that evidence suggests reduced interaction limits cultural development, whereas increased interaction, although conflict-ridden, pushes it forward and develops it in new directions. [Answer] You need to keep digging for stuff. Lots of good examples here. Here's a few more: * Mediterranean soils tend to be loose and sandy. Tillage was in effect done with a sharp stick, dragged back and forth in a cross hatch pattern by oxen. * Northern soils were heavy clay, and farming was essentially impossible until the creation of the mouldboard plough. The horse collar, and the breeding of heavy draft horses helped. Fields were long and narrow, because turning a plough is hard, and so that the eventual crown to the field (soil is always turned toward the centre) created drainage ditches, which allowed the fields to be sowable earlier in spring. * Climate has a huge influence on architecture. Cloisters -- essentially large covered porches give living areas protected from rain, but fairly well lit. Windows before glazing are cold. Scots peasants had 'black houses' No windows at all. Just the light from the open door or the sullen glow of a peat fire. Monks in scriptoriums in northern climates complained about their ink freezing. There are reasons why 12 century portraits show so much clothing. Houses were built with living quarters above stables. A cow is a 2500 BTU/hour thermal machine. You don't let that much heat go to waste. You see this even today. Houses in southern areas have large windows. Sometimes the boundary between inside and outside is blurred, with outdoor kitchens, patios... Housing in northern climates tends to smaller windows, tight fitting seals on doors, storm entrances. * climate has a huge influence on clothing. Imagine a roman toga in Lapland during mosquito season. Those multiple layers of thin white fabric of the desert peoples are actually cooler than skin. In a humid tropical climate, skin works better. This in turn had effects on what was considered moral behaviour. * Cities tend to grow where products have to change direction, or mode of transport. On land look at where major routes cross. On rivers, look at the mouth, and major confluences. Obstacles, such as falls, or mountain passes also create cities. The pass may only be open part of the year. The falls requires portaging all your gear and goods, and perhaps the boats. See history of the Silk Road for more examples, as well as where cities sprang up on the Mississippi/Missouri/Ohio river systems. An example of the latter: The Canadian fur trade uses Canots du Maitre to haul from Montreal to Grand Portage. This was a 36 foot canoe. Voyageurs carried goods over the Grand, (9 miles) but they used a smaller Canot du Nord, about 23-25 feet long with about half the cargo, but only one less paddler. They didn't portage canoes over that portage. Later on, furs came south on the McKenzie, and Slave rivers then up the Athabasca to Athabasca Landing, transhipped by cart to Edmonton, then down the Saskatchewan, and down the Hayes to Hudson Bay. The round trip for trade goods for furs took 6 years for the extreme ends of the trading empire. * In island archipelagos, people on opposite sides of a straight often have more in common including language than people on opposite sides of the same island. It's easier to move by boat. See south west pacific (China sea, Coral Sea, Indonesia...) for examples. * In the Canadian Arctic it's reasonable to travel thousands of miles along the coast by dog team. (Distances of 100 to 150 miles a day on smooth ice are reasonable.) Traveling inland is much more difficult. Languages reflect this with each area's language being mutually comprehensible for about a thousand miles either way from Point Barrow to Greenland. However coastal Inuit and Caribou Inuit had different languages -- and different technologies. Coastal groups are based on hunting seal, both on the ice, and by kayak on water. Inland groups are based on caribou. Further inland you get Indians (I'm at a loss here for the proper term to distinguish Innuit from other first peoples...) with the boundary being roughly treeline, and a much greater dependence on wood as a material for making dwellings and tools. * Variable climate requires civilization of some sort. Variable climate means one year's food production isn't guaranteed. Food storage becomes a critical factor in the stability of cities. There was a lot of grief in the Mediterranean about 1150 BC with a climate shift that dropped crop yields. See also the old testament stories of Joseph, and fat/lean years. This applies to nations too. India used to be unable to feed itself in my memory. The green revolution of fertilizer is one reason this has changed, but a bigger reason was rat proof grain storage. * In addition to Diamond's books, already mentioned, look at James Burke's book, "Connections" It details a bunch of interacting bits of technology, history, climate, coincidences, and show how some changes are pretty arbitrary, but others are inevitable. [Answer] The short answer is the higher the level of technology, the less that culture depends on geography. But the initial trajectory of a culture is shaped by geography. Primitive and early humans were completely at the mercy of their environment. If you live next to a river, then you have a chance of setting up agriculture. If not, then you're stuck with hunting-gathering. If you live next to a cliff with natural caves, then you have a convenient place for shelter. If you live in the rainforest, then you're going to have to improvise a shelter on your own. Cliff-dwellers don't need to learn how to build houses. All of this will affect how people live together and form a society, what they eat, who they worship and how. In other words, their culture. However, as technology advances, "geography" shrinks. Nowadays we can drive over 100 miles to see an event; traveling such a distance would take many days and be very hazardous for a medieval peasant. We can chat with a person in India in real-time through our computer. We can eat fresh fish in the middle of the Arabian desert. We can order clothing made from silk in China and have it shipped to Nigeria. We can fly to Paris to see the Eiffel Tower in person. Technology has eliminated many of the constraints once forced upon us by distance. There are still some practical limitations. We can move out of town if we don't like living here, but it is a hassle. We might drive to a more distant restaurant that we would not consider walking to, but a three-hour drive is probably out of the question. We tend to form friendships with people that we meet in person i.e. within close proximity. In the future, even these constraints will probably vanish. Then we can effectively be wherever we want, eat whatever we like, and hang out with crowds we like, however distant. Geography will play little role in the picture. But beginnings are often the most influential stage of life. All societies begin at the primitive level and slowly develop technology, of course. Which means that their initial culture was, in fact, profoundly shaped by their starting geography. This would have an impact on what kinds of technology they develop, which would in turn change how the geography affects them, and so on. Thus, all cultures emerged from, and developed in certain ways in response to, local geography. This leaves a lasting mark on the traditions of that culture. However, once cultures become advanced enough and start interacting with each other, the direct impact of geography declines. What remains are the lingering effects of the initial traditions shaped by their "original" geography. [Answer] try and think about which factors of the land are constant, and then let your imagination run from there. what sort of culture can you imagine sprouting from each area? it shouldn't hold you back, just offer some seedlings or cores for your 'traditional' cultural identities. before things get modern, you'll notice that culture is closely tied to the land. remember that most people are born and die in their own bubble, which may consist of rice paddy farming all day, or working in massive metropoli, or spending their days on the sea, and to this day you can find these remote bubbles of culture and it'll all to various degrees take on the outer appearances of the broader cultures around them, but the details will all be closely tied to the land and natures cycles and what they have to work with. try and consider all of japans region-specific festival topics, and compare it to them eating kfc on christmas perhaps its more important to consider how fluid the culture of each place is, and then have geography win over the broader cultures, that you're free to paint onto your maps, in rural or distant or closed-off places. that way is more natural ]
[Question] [ My question is as follows - let's assume our objective function is to have as many humans as possible living outside the confines of the Earth as soon as possible. For this, we need to provide those humans with some habitat outside Earth. One approach is to try and colonize other bodies in the solar system like Mars. Another is to build our own habitats, starting with the vicinity of Earth. Which of the two approaches will get us further in terms of the stated objective function if we start investing resources into one or the other now? --- There is talk of inhabiting Mars and making life multi-planetary. I personally think the Moon is a better bet, but another approach is to simply start expanding the International Space Station so it can support more and more people. Then, we can simply build more of those. These large ships would start to collect more and more energy from the Sun, which is going towards a Dyson swarm. The question is, why even bother going to Mars and inhabiting it as opposed to just disassembling it for material when the time comes? Is it substantially easier to build a life-sustaining habitat on Mars than an independent spaceship? The advantages Mars might have are that it has a lot of rock under which a human colony can get shelter from incoming radiation. Also, it has some gravity which we humans are accustomed to (though just a third of Earth). The advantages of the space-station approach is that you can stay close to Earth. This is valuable in terms of being able to get supplies there much faster, help arrives quickly in case of emergencies, the close contact ensures much less psychological hardship for the inhabitants who can always go back to the planet for visits, do Skype calls with relatives, etc. You can also stay within the Van-Allen's belt so you don't need too much extra shielding, at least in the initial phases. Also, for intermediate economic motivation, this ever-expanding space station could start as being an exotic hotel for the wealthy. So, if our goal is to have our species acquire a substantial footprint outside the Earth, should we invest our resources in going to Mars or the Moon and set up shop there or simply start expanding the space station to the point of a city and then rinse and repeat? To me, the latter option seems much more logical but am interested in alternate opinions. [Answer] # People are not suited for space. The thing is the same is true of Mars. People are not suited for anywhere in our solar system off Earth. We have a K1-level biosphere that we are highly adapted to. Replicating it elsewhere sufficiently well is hard. # The first step is to get rich And for a modest initial investment, we can upgrade a humanity-derived civilization to somewhere between K1 and K2. We'll start with asteroid mining, with lots of support from Earth. Suppose every 1000 units of resources used on Asteroid Mining over a year means that next year you get 1 more unit of Asteroid Mining for the same input. This is a 0.1% growth rate. You start a huge project and build a robot run factory on Ceres. It builds tugs that go out, land on asteroids, deploy solar cells and use ion drives to fire asteroid dust and navigate the asteroid to the factory. At the factory, they smelt the asteroids and generate more raw materials. Over a century, we throw resources at it, and it ramps up to mining 10,000 tonnes of raw astroid material per year. Initially some components have to be imported from Earth. Over time fewer components do. The rate at which asteroids are turned into faster asteroid mining increases, from 1 part in 1000 to 1 part in 100, over the first thousand years of doing this. # 1000 years from now So we are now 1100 years away, and Earth is finally tired of asteroid mining. However, the mining base is now self sustaining. It mines 10,000 tonnes per year, and every year it mines 1% more. The asteroid belt has a mass of 10^21 tonnes, with half of it being the large bodies. Those large bodies are going to be converted into more processing facilities. 10^20 / 10^5 = 10^15 years. So to start, this takes forever. But we have our 1% growth factor. In about 3000 years, our asteroid mining robot civilization wuld be capable of consuming the entire belt, besides the larger bodies. It will also have started on some of the smaller moons of the various planets. # 4000 years from now So about 4000 years from now, we have a swarm of mining robots collecting energy. They proceed to build beanstalks on some of the larger moons (Titan, Luna and the 4 Galilean moons of Jupiter). They sum to 10^24 kg or so. If it is twice as hard to beanstalk these and get the resources out to our robot mining swarm, it takes another 2000 years to dismantle these. # 6000 years from now At this point, dismantling Mars and Venus is easy. And we have an orbital (robot) civilization which can build things on the scale of planetary ecosystems with ease. If you want to coddle humans and have them live in Earth-like environments, it now is cheap to keep some as pets. Now, some point along this journey, before this end point, we could probably build fortified planetoids where humans live under the surface. But it would probably be easier to just record a human consciousness and upload them to a machine body more suitable for working in space than maintain a terrestrial biosphere. But, barring new technology, this kind of path is probably the "fastest" one to get rich enough to be a K1-2 civilization. And if there is new technology to be had, nothing pushes innovation like having a 6000 year of future efficiency to improve. Barring an extreme growth factor, the time this takes scales linearly with your growth factor. 5% per year means this entire thing takes 1200 years. 10% per year means it takes about 600 years. 0.1% per year means it takes 60,000 years. (When you pass 10%, second-order effects change this approximation). [Answer] Mars is the better bet There's a reason why building habitats on Mars makes more sense, and many of them are covered in the Mars Trilogy by Kim Stanley Robinson. The simplest and most plausible reason though is that Mars is already a 'spaceship' in a stable orbit around the sun, so all you have to do is populate it with the people and resources you need. You don't need to design spinning habitats, then build them while depleting the Earth's resources to do so. In theory at least, Mars is likely to have some mineral wealth that can be exploited once we're there and there seems to be some compelling evidence that it also has a water (or ice) table that can be exploited as well; for drinking, fuel and oxygen. Whether or not Mars could be terraformed in the same manner as described in the trilogy above without massive investment from Earth is a question for which I don't have an immediate answer but if it can, then it's going to beat out habitats every time simply by virtue of the scale. You may be able to put thousands on a habitat, but Mars could (potentially) hold up to a billion. That is likely the upper bound I grant you, but the simple reality is that in terms of scaleability Mars will beat habitats every time. If you're looking for the greatest possible numbers off the earth in the shortest possible time, and you've got unlimited resources to do it, then Mars is a bit like a steam engine car racing a petrol engine car; if you're measuring shortest possible time in terms of years, or even decades, then go with the habitats because Mars simply can't scale up that fast. But, if you're measuring shortest possible time on a scale of centuries, then go to Mars straight off the bat. It'll take longer to ramp up, but once you get it going you'll simply be able to house more people faster because building a habitat on the surface of Mars is going to be MUCH simpler than building one on Earth, launching it into orbit and assembling it, then filling it with air and populating it. Also, there's a chance that Mars might eventually be able to build habitats out of materials sourced from Mars, whereas that will never happen in orbit. That means that your efficiency goes through the roof. A quick comment on the Moon; pretty much everything that I've just said about Mars could also apply to the moon, except that it's unlikely to have water reserves. Also, we don't know a lot about mineral wealth housed on the Moon, although He3 has to be a great energy source if we can use it in fusion generators. The moon would also have the advantage of being closer, and the lower gravity well by comparison to Mars also means that if the moon ever has anything to export, it's going to be able to do so at a much cheaper rate than Mars can. All that said, if people have to be off the Earth, whatever is going to cause them harm there, if it's astronomical in nature (say the sun, or an asteroid) is just as likely to cause issues for the Moon as well. Also, no water would mean that lots of it would have to be shipped up (at great cost) with potential colonists, and being smaller means that the upper bound of colonists is much smaller than what might be possible on Mars. But again if you're not staying there for the long haul (no pun intended) and you're only interested in numbers over a short period, it might be a viable option, especially with the aforementioned unlimited resources to do it. [Answer] First, we don't know how to build a self-sustaining ecosystem that will support humans indefinitely at anything much smaller than planetary scale. Consider that the ISS needs a resupply mission every month or so, just to support a crew of 3-6 people. Second, the difference between a (terraformed) planet and a Dyson swarm is like the difference between a country estate and an urban tenement. The quality of life would be vastly better, and since people who can afford to go to space on their own dime (rather than on missions paid for by governments) are going to be wealthy, the amenities matter. PS: Of course we could envision situations, such as Heinlein's "The Moon is a Harsh Mistress", where the Dyson sphere or unimproved planet/moon is treated as a sort of super Sibera/Australia, so only "undesireables" are exiled there. [Answer] # Venus I think Tim B II did a great job of summing up why we'd want to choose a planet over space habitats but its interesting to think about if Mars is that planet. I know you specified a Mars vs space habitat scenario (though you do say "One approach is to try and colonize other bodies in the solar system like Mars") but Venus has some great stuff going for it. * thicker atmosphere than Mars (better protection from space radiation) * closer than Mars (so less money on fuel to get there) * more available solar power (because its closer to the sun) * gravity is closer to that of Earths (low gravity hasn't been good for health) * we'd get to build cloud cities (though as cool as that sounds its a bit of a hassle) There is a great PBS video on this: <https://www.youtube.com/watch?v=gJ5KV3rzuag> [Answer] # [Gravity wells is for suckers](https://www.youtube.com/channel/UCogrSQkBJn1KF0N9I4oM7eQ) One of the largest stumbling-block to getting to K2, is the tyranny of the rocket equation. Getting out of a gravity-well is *really* expensive. Obviously we have no choice, we're stuck on earth, however, we should only do that once. The solar system can support a billion-folding of population, with current living standards, but all that certainly do not fit on planets. Furthermore, planets offer no advantage over orbital habitats, unless they natively support life. Only Earth does that, the rest are just as inhospitable as space, with the added downsides of: gravity well, quakes, dust-storms that lasts for years, perchlorates etc... In orbit, you have, for example, solar-power available 24/7. In just one asteroid, like Ceres for example, you have more metal than humans have mined, in total, through all history. Colonizing mars lets us increase our pop-count with a factor of 1.5, or so. A Dyson lets us increase it with a factor of 1000000000. Planets are building material, once we run out of asteroids and moons. 'Terraforming' isn't likely to be in many technological civilizations future. Dyson-swarms, on the other hand, are considered by those that have this as their field of expertise, to be close to unavoidable. [Answer] The main obstacle to building space habitats is material which must be lifted out of gravity wells, which is extremely costly and does not scale well. By contrast, most elements needed for habitats will be available on planets, potentially needing some mining and trivial ground transport. The gravity issue would be avoided if we managed to exploit asteroids. But instead we would face the need to align speeds and (usually) shed lots of delta-v which is also costly. By the way, I recommend [Seveneves](https://www.nealstephenson.com/seveneves.html) by Neal Stephenson which involves issues of both planetary and interplanetary habitats. ]
[Question] [ Ever since I found out about the green blooded skink, I have wondered if it's possible for other blood colours to evolve among vertebrates, specifically blue in mammals. [Answer] [![enter image description here](https://i.stack.imgur.com/U66CP.jpg)](https://i.stack.imgur.com/U66CP.jpg) [![enter image description here](https://i.stack.imgur.com/3mN1y.gif)](https://i.stack.imgur.com/3mN1y.gif) For endotherms, iron is in the heme groups binding oxygen, yielding a reddish color. For ectotherms, copper is in the heme group binding oxygen, yielding a bluish color. > > In order to bind oxygen, each protein chain binds to one heme group, allowing a maximum of four oxygen molecules to bind per one hemoglobin molecule. > > > At heme's center sits an iron molecule. The iron makes heme look red-brown. But what if the iron is swapped for a different metal? > > > ...in cold-blooded animals, blood appears blue because copper atoms sit at the center of the ring and bind to oxygen. > > > [link](https://www.medicalnewstoday.com/articles/318171.php) It is probably a good bet that binding affinities for the iron-heme-O2/CO2 complex at 98F are better attuned to optimal gas exchange relative to the copper-heme-O2/CO2 complex, since this is precisely the substitution which occurred during mammalian evolution, thru many intermediate steps, doubtless, including modification of the carrying protein/heme platform. Which means blue blood is not favored relative to red blood, for mammals. Impossible though? Such an experiment could perhaps be run by depleting iron and raising the availability of suitable copper sources. That would be something for a molecular biologist to grapple with. I expect toxicity would likely be a large experimental hurdle, the process likely including reactivation of hemocyanin biosynthesis, per Molot. [Answer] I can't see why not. [Octopi have blue blood](https://animals.howstuffworks.com/marine-life/why-is-octopus-blood-blue.htm). Apparently its due to a protein called Hemocyanin that binds with copper. So its clearly physically possible in complex Earth life. [![enter image description here](https://i.stack.imgur.com/WBeWR.jpg)](https://i.stack.imgur.com/WBeWR.jpg) [Answer] It's not only possible, it has been documented, in humans, within the past century. Google for the "blue Fugates" -- they were an inbred family/community in Kentucky who, due to a mutated gene, had a much higher than normal level of methemoglobin. This altered hemoglobin doesn't carry oxygen efficiently, but it is quite blue in color -- blue enough to overpower the normal pink skin color in Caucasian humans. The belief is that the Fugate family had a couple members who were born with this mutation, and as a result they were shunned by others. Add this to geographic isolation, and you get inbreeding. Over a period of a couple centuries, this led to everyone in their extended family (which was their entire community) having blue complexion. After the family broke their isolation in the late 20th century, physicians found a simple treatment: injection of methylene blue dye converted the methemoglobin to common hemoglobin, and their skin color changed from blue to pink in minutes. Periodic treatments are needed, and the mutation is still present in their family/community, so the Blue Fugates aren't gone, they're just hiding among us. [Answer] Vanabins [![blue sea squirt and structure of amavadin](https://i.stack.imgur.com/XO0yF.png)](https://i.stack.imgur.com/XO0yF.png) image of ascidians: <http://frontiersmagazine.org/post-11/> Amavadin: from <https://en.wikipedia.org/wiki/Amavadin> Vanabins are vanadium containing molecules found in sea squirts and some other organisms. Depicted is amavadin which is from a mushroom but which I think is more hemoglobin-like than the true "hemovanadins" from ascidians. They were called hemovanadins because they were thought to participate in oxygen transport but according to what I read that is now in doubt because these creatures have hemocyanin too. Oxygen transport still seems likely to me. In any case: they are hemoglobin analogs, they can do oxygen transport and they are awesome colors of blue and green. Hemovanadin blood could be a fine blue color. --- But why would a mammal use vanadium for oxygen transport when iron works so well? What if the iron brought trouble with it? That is actually the case for mammals - infectious organisms also want iron. When you are infected, a molecule called [ferritin](https://en.wikipedia.org/wiki/Ferritin#Immune_response) grabs all the iron it can, denying it to the infection. > > Immune response Ferritin concentrations increase drastically in the > presence of an infection or cancer. Endotoxins are an up-regulator of > the gene coding for ferritin, thus causing the concentration of > ferritin to rise.... Thus, the iron stores of the infected body are > denied to the infective agent, impeding its metabolism.[24] > > > A consequence of this in real life is anemia - bound to ferritin, iron is denied to the red blood cells too. What if there were some prevalent infection which depended on an organisms iron? An organism with minimal iron would have resistance to that infection. If infected, it would not have to get anemic because its cells are using V not Fe. Even if vanadium is less efficient at oxygen transport, the disease resistance conferred could cause hemovanadin-based blood to spread throughout the population. How could mammals get hemovanadin? The sea squirts are our distant ancestors. Perhaps the gene for hemovanadin is still in mammalian DNA, sequestered and unused in some dusty corner of the genome. An accidental mutation restores it, and it is used shoulder to shoulder with iron hemoglobin, conferring advantages. Later an organism mutates out the hemoglobin gene leaving only hemovanadin - with consequent improved fitness. [Answer] I know you said blood, but it is documented that colloidal silver taken as a supplement causes argyria which turns the skin blue. Colloidal silver is used often to sterilize water among other things if this helps any. [Answer] I am going with probably not This is entirely possible in the sense of why not. Its not like blood color is a factor in its function, merely a byproduct. Its just our evolution resulted in iron based hemoglobin so walla red blood. Here's why I say probably not: We and most mammals are pretty complicated organisms. Blood is a pretty basic functioning trait. Its kind of unlikely that evolution would seek to revise our blood color without a strong reason. Some would hat wave mating for this but I feel its pretty safe to say blood isn't going to play out in most mammals mating habits unless vampires become a thing. Maybe our nature can find improved immunity function that changes its color. And this is really the complicated part. Finding some adaptation that requires significant change in the blood chemistry to result in change of the color. [Answer] It is possible. Hemocyanin would be what you would use and not hemoglobin. As stated, hemocyanin is worse at oxygen transport, compared to hemoglobin. But not all hemocyanins are the same, there are more effecient versions with better cooperative binding. If you go with methods of [directed evolution](https://en.wikipedia.org/wiki/Directed_evolution), we use to produce better [enzymes](https://www.chemistryworld.com/news/what-is-directed-evolution-and-why-did-it-win-the-chemistry-nobel-prize/3009584.article), you could hope to produce hemocyanin, that would be good replacement for hemoglobin. That for sure would take a lot of changes in your body to make it work well after that. But it is possible. ]
[Question] [ ## Premise Suppose an [earth-like](/questions/tagged/earth-like "show questions tagged 'earth-like'") world in the [near-future](/questions/tagged/near-future "show questions tagged 'near-future'"). Then aliens come and decide to play a mischievous trick on this world on an epic scale. The goal is to disrupt Earth's time by 18 minutes. Specifically, they wish to make the time on Earth 18 minutes slower within 24 hours. It's a one-off prank, just to show they can. ## Question Assuming the aliens have very advanced technology, but are still confined to the known laws of physics, what relativistic feat would accomplish their goal? Further Clarifications * Goal: slow down time on Earth by 18 minutes * Quality Metric: the more perceptible to the Earthlings the better (if the Earthlings don't even realized they've been pranked, where's the fun in that? However, direct perception of time slowing down might not be possible and I'm willing to live with that. So the other component to the quality metric is if there were simply some glaring clues for the victims to realized they were time-pranked recently, that would also be favored by the quality metric.) * Technology: The exact limit of the Alien's technology is uncertain, but what is known is the technology must comply with known laws of physics * Timeframe: The 18 minutes must be slowed down in the span of 24 hours. You may assume a lengthy preparation phase prior to the implementation of the prank if necessary. * Nature of Prank: The prank is not intended to be permanent. The idea is we are taking one Earth day and slowing it down by 18 minutes; a one-off. Note: Changing the rotational speed, while not overtly out of scope, would not get to the heart of my problem, since we are dealing with perception of time as a quality metric. [Answer] ## Nothing we know of could achieve that. There are two things that distort time: velocity and gravity 18 minutes per 24 hours is a dilation factor of 1.0125. ($\frac{24hours + 18minutes}{24 hours} = 1.0125$) ### Velocity Velocity is out of the question as you can't just accelerate the planet and have it keep a stable orbit around the sun. Also you would heavily quicken the year as your position around the sun would change drastically. You can not use $$T\_0' = \sqrt{1-\frac{v²}{c²}} \times T\_0$$ without changing lots and lots of other things on earth. Also time dilation by velocity is not a simply thing and works both ways. Relativity is not just spacetime-bending, but also mind-bending. Takes a while to wrap your head around that. ### Gravity Time distortion by gravity is a very tricky thing. And it would come with loads and loads of side-effects that are probably unwanted. You would need a very heavy mass near earth to distort time to that extend. It would just have to pop up and disappear, too. And not change the path of earth at all. For reference: [![Time Dilation Effects on Earth](https://i.stack.imgur.com/Nx03S.png)](https://i.stack.imgur.com/Nx03S.png) A picosecond is 10^-12 of a second. So a tiny fraction of a second. What you want is for a span of a day to gain 18 minutes. You want 12.5 milliseconds per second. In this image you can see that earths gravity distorts time by less than a nanosecond per second. So you would need something incredibly more massive directly near earth. Also, as I mentioned, it would entirely screw up your orbit and everything. --- ## A note: Spacetime is a weird thing. You can't just delay or slow time, by means we know of. It is always an interaction of things that works both ways. Without heavily altering something in spacetime you can not heavily alter spacetime. (1.0125 time dilation is a heavy alteration to a balanced system of orbits) [Answer] As others have pointed out, messing with spacetime here on a scale that doesn't screw up earth's orbit, etc etc would make time seem slower for people observing us from a different frame of reference. Since we want as many people as we can to notice we can: Alter spacetime around the objects we use to measure time One could argue that most people tell the time by their phones and computers, not whatever the sky says. Computers sync their time from several servers, that get their time (in part) from [400 highly precise atomic clocks that determine International Atomic Time](https://www.timeanddate.com/time/aboututc.html). By screwing with the devices that the entire species has decided to use to keep time, we will, for a lot of people, effectively slow down time. People will have to work longer if they are following a digital clock to check out of their shift, banks will open just slightly latter than they should, pissing off a bunch of people, etc. How to achieve it Bend spacetime locally (around each clock) so they seem slower from the perspective of everybody else. Since we're not changing gravity for the entire planet, just the clocks, we could probably achieve it without messing too many things up by placing a very dense dark matter-like material close to each clock. You could use less mass if you were to solely warp spacetime around the of the clock Caesium. This can be done by either casually teleporting in and out the material, or by using advanced stealth devices that the aliens have. Hopefully that's clearer! :) [Answer] A long-term and harder version of some of the "illusion" pranks... Also, to pull it off in "near future", they would have to have already started preparations. The aliens get a giant (and I mean GIANT) lens - ideally something fairly flat, like a high-tech Fresnel lens - then position & keep it between the Earth and the Sun. When the lens is straight on, no problem - but, by moving it sideways and angling it slightly (relative to the Sun/Earth line), they can bend the light from the Sun, causing it to appear in a subtly different part of the sky. If they move it enough to make each day approximately 0.05 second shorter then, after about a 10 years, the day will have been shifted by about 18 seconds. After about 600 years, the day will have been shifted by 18 minutes, and leap-seconds/minutes etc will have been added to "correct" time such that Noon is Noon. Then, one day, they just remove the lens - jump it to FTL during a Solar Eclipse or something. Boom, that day is suddenly 18 minutes too long/slow. [Answer] A less technical solution: Have the aliens simply do it the old-fashioned way, and hack into all electronic timekeepers, set them such that their time runs slow/fast by 18 minutes (adjusting their perception of the length of one second so they don't notice immediately). Yes, this would be really hard, but easier than speeding up the whole planet or something, and this gets really easy if most Earth timekeeping devices use the internet to update their time. It'd be really funny when tides stranded boats and stuff and sunset times were off and the like. Plus everyone's metronomes would no longer have 60bpm as one beat = one second when they checked with their clocks, but only on that day. [Answer] This is not making time itself slower, but making the rotation of the Earth slower, stealing 18 minutes from a day: Push a large amount of water from the poles to the equator, slowing down the rotation of the Earth. I am not going into the formulas to calculate the amount of water need for the size of the effect nor the increase of sea level at the equator. An alternative method to achieve the same effect is to push a lot of mass into the atmosphere (preferably around the equator). [Answer] Our current knowledge of physics allows us to travel forward in time, but not backwards, so the aliens would be able to slow down time, but not revert. But as already stated, you can [slow down the rotational speed of the Earth](https://worldbuilding.stackexchange.com/a/124646/32789) by moving the moon closer to Earth until it's just a few minutes slower. This will not take 24 hours though ¹ but this will allow you to build up suspension: * Astronomers would notice quite quickly but would be too afraid to publish as this is quite impossible * Governments would try to suppress the information because + The military's smart bombs would stop working + GPS-based ankle bands would stop working + ... * Governments would not be able to hide it any more because people's own GPS systems would start to glitch ²: + Cars driving into rivers and off bridges + Airplanes landing on the wrong runway + Back to [sextants](https://en.wikipedia.org/wiki/Sextant) for nautical navigation! + People's satellite TV dishes would be out of alignment! (No! More! T!V!) + Satellite Internet would stop working + The moon is getting bigger! The reason for the practical joke? It's just a stunt of one of their ~~TV~~ 3-V stations doing a Reality 3-V show back on their planet showing the misery of planet Earth! The misery is stopped in 24 hours by moving all geosynchronous satellites back into alignment. Note ¹: I need a cosmologist's help to calculate how long it would take. Note ²: Geosynchronous Satellites would be out of alignment (the old ones) or run out of fuel pretty quickly (GPS satellites) [Answer] ## Using astronomical amounts of positive and negative mass If aliens construct a massive shell around the Earth, they will indeed slow the time on it, without causing any gravitational damage inside if the shell is spherically symmetric (because of the [Birkhoff's theorem](https://en.wikipedia.org/wiki/Birkhoff's_theorem)). However, for a sufficient time dilatation, the shell would have to be very massive, so massive that it would mess-up the Solar system. Solution: Bring equal amount of negative mass. By constructing two concentric shells, one made out of positive mass, and the other one made out of the same absolute amount of negative mass, the same effect can be achieved, depending on relative radii of the shells. As before, there would be no additional gravitational field inside the smaller shell, but now there would also be no additional gravitational field outside the larger shell, because they would cancel-out. Only the space between the shells would have extremely strong gravitational field. These two shells would be the gravitational analogue of a spherical capacitor. Because aliens want to slow down the time, the negative mass shell should be larger, and the positive mass shell should be smaller. Otherwise, they would speed-up the time. Time dilatation is proportional to the gap between the shells, so for a smaller gap, the shells should be even more massive and negatively massive, but this shouldn't be too big problem, because the total mass is zero. The problem is creating and maintaining such megastructure (because [energy conditions](https://en.wikipedia.org/wiki/Energy_condition) should be violated for negative mass and the immense gravitational fields would threat to tear the megastructure appart), but let's assume that aliens figured that one out. Other problem is the light and other EM radiation passing inside and outside. If aliens make their megastructure simply transparent, there would be a gravitational redshift/blueshift, not detectable by naked eye, but certainly detectable by spectrometers. If your aliens fine with it, than this is all they need. If not, they would have to make the superstructure slightly more complicated by installing cameras and screens which would stop redshifted/blueshifted EM radiation, and emit the "corrected" EM radiation. [Answer] The problem I think is that the question is basically trying to un-prove relativity. Because time is always relative to the inertial frame of reference there wouldn't be any way for anyone to actually even notice that something had changed. Of course, assuming that you don't want the solar system to come flying apart from the massive gravitational changes required to dilate time around just the Earth, you are left with dilating time around the entire solar system. Then assuming that the aliens can somehow (casually for a joke remember) generate the insanely huge amounts of energy required to accomplish this you would still have the problem that no one would probably notice. Perhaps astronomers might notice that the position of a nearby star is off by 18 minutes of time, however over that great a distance, it doesn't seem that it would be noticeable. [Answer] 18 minutes is 1/80th of a day. Being next to the event horizon would stop time completely, so this is in some sense 1/80th the effect of a black hole, which is a massive amount of distortion. However, it would not be enough to put 1/80 of a black hole next to the Earth. That would produce so much gravity that humans wouldn't notice the 18 minutes, because they would be distracted by the whole "crushed to death" thing. If you are equidistant between two black holes, the time dilation of the black holes will reinforce each other while the gravity cancels out. So maybe they can do something similar. However, that raises the issue of tidal forces. Putting the mass further away reduces tidal forces, but also increases the mass the aliens need to use. Another issue is whether all this matter will block out the sun. So maybe the aliens are using dark matter. Of course, dark matter, by definition, interacts very weakly with normal matter, so this will raise the issue of how the aliens are manipulating it. So the best candidate would be a massive shell of dark matter surrounding the Earth carefully manipulated somehow to avoid large gravity gradients in space or time. What about accelerating the Earth to a high speed? Well, for low speeds, we have the approximation $\gamma = 1+\frac{v^2}2$. So for an effect of 1/80, we'd need $v=\sqrt{\frac{1}{40}}$, which is about 0.158. That is, Earth would have to be accelerated to .158 of light speed over 24\60\60 seconds, for an acceleration of 5km/sec/sec, 500 times Earth's gravity. And that's not even taking into account that you would have to decelerate back down to normal speed, and that you would have to accelerate to a higher speed to account for the fact that you're not spending all the time at top speed. [Answer] Could the aliens trick the human population into believing time has changed? A mass hallucination, caused by something in the air or water. The best part of the prank is that you're not going to get everyone to be affected - the aliens could use those people as "the rational ones" who end up getting more and more frustrated by the rest of the world who are not realising something is wrong. Hilarity ensues. This shows off the aliens technical abilities (able to poison an entire planet, able to create a poison for people that only affects them for 24 hours and - aside from the hallucinations - is completely harmless). [Answer] If a sun is like a proton on an atom nuclei, every planet would logically be exactly as an electon's field! Assumption 1: slightly concave "flat disc" shaped planets, clouding around a common proton plasma emitter! THEN apply a torus shaped movement between the 3 main toral moments! Electrons and electronic clouds do this.. an electron gets bigger and further away from the proton as temperature rises and will get smaller and closer to the proton when temperature drops! NOW you get a couple examples for each of the torus 3 moments: super-dense sphere like Mercury or Venus Separation moment: when the sphere turns to a donut with almost a whole, but still closed like earth and mars And finally the donut phase. When the planet grows so much that actually gets a whole in the muddle! The donut planet theory almost address the point, but misses it widely by assuming the crust would be the outside of the donut, when in fact, the crust would be the horizontal plane of a the vertical midsection cut... Therefore being perceived as mountain and ice on superdense sphere state, plainny and w/liquid water like earth or mars and scarce, gassy and with a whole in the middle like saturn Uranus & Neptune... The gassy nature of the plane is just but a misinterpretation of data! Where we assume the planet is, there is in fact nothing but the north central vortex aka light whole! We perceive the whole to be the planet because exclusively of the gas atmosphere! Which is easy explained considering a torus donut planet with a gassy atmosphere covering ALL: hole, water and rock around! Fact the gas planets with belts have rock and water/ice on the belts and nothing but gas in the central area... Check the link for a few basics on torus <https://en.m.wikipedia.org/wiki/Torus> So, answering your question: there are no aliens, the earth is simply decreasing ray, cooling and getting shorter days... We call it ice ages, but virtually no one has a clue why! You will have discrepancies in time loss depending on how far north on the planet you are... Difference should be more discernible far south, losing more day time! Put some black suits at my door if you're interested in the whole picture :) [Answer] Really REALLY brute force. Slow down time for the entire solar system with a really big distortion of space-time. The only people who notice it are astronomers studying the timing of stuff outside the solar system. For example, the folks watching the signal from the Pioneer probes. Or people studying pulsars. Semi-empirical models of pulsars can identify and predict individual pulses to a really wonderful degree of accuracy. When dozens of astronomers start complaining about the missing 18 minutes, people start to put things together. When both Pioneer probes are 18 minutes "fast" people really start to joggle the old almonds. Also, the stars will look a really weird color for a while. All at once all over the sky. [Answer] Okay for a one-off slow down of 18 minutes you need a space-time disruption of some sort, you aren't messing with Earth's rotational period in any way but rather the way the world experiences time. This would make a single day 18 minutes longer for the world than the one before or after it. That will throw every clock dependent technology completely out of calibration, including but not limited to satellite communications and GPS systems. How would you do such a thing? I can only think of one effect which would be to artificially accelerate our frame of reference, objects travelling at higher speeds experience time dilation such that they take longer to experience the same amount of "real-time". If you accelerated, and then decelerated (to get things back to normal), our reference frame sufficiently we would experience 18 extra minutes. That's an [ASB](https://tvtropes.org/pmwiki/pmwiki.php/Main/AlienSpaceBats) feat though, I can't even begin to quantify the energy you'd need to pull it off. There would be some longterm ramifications, including but not limited to the fact that stellar navigation would be messed up until all new co-ordinate tables were created because our relative position in the galaxy would get a sharp jolt. ]
[Question] [ Julius Caesar used a substitution cipher (now called a Caesar cipher) for sensitive private and military correspondence. The cipher involves shifting all of the letters in a message in one direction a secret number of times, wrapping around if necessary. This appears to have done well for Caesar, but could he have done better? The cipher itself is quite trivially breakable. What if Julius Caesar had been given access to a one-time pad, or OTP? An OTP is an encryption technique that is unbreakable when used correctly. The key must be the same size as the message and completely random, but if it is, it provides information-theoretic security. The way it works is simple. The pad is the same size as the message to be encrypted. You add the position of each letter in the pad (1 for A, 2 for B, etc) to the position of each letter in the message, modulo the size of the alphabet. An example encryption of "HELLO" using pad "XMCKL" from Wikipedia: ``` H E L L O message 7 (H) 4 (E) 11 (L) 11 (L) 14 (O) message + 23 (X) 12 (M) 2 (C) 10 (K) 11 (L) key = 30 16 13 21 25 message + key = 4 (E) 16 (Q) 13 (N) 21 (V) 25 (Z) (message + key) mod 26 E Q N V Z ‚Üí ciphertext E Q N V Z ciphertext 4 (E) 16 (Q) 13 (N) 21 (V) 25 (Z) ciphertext - 23 (X) 12 (M) 2 (C) 10 (K) 11 (L) key = -19 4 11 11 14 ciphertext ‚Äì key = 7 (H) 4 (E) 11 (L) 11 (L) 14 (O) ciphertext ‚Äì key (mod 26) H E L L O ‚Üí message ``` A random pad can be trivially generated by flipping a coin to determine which letter is present. The pad is delivered securely to the correspondents. It is one of the few concepts in cryptography that are completely and provably unbreakable. How would the Roman Empire's role in history change if: * Julius Caesar and his private correspondents knew of the technique? * the concept of the OTP itself was widely known throughout the empire? In practice, the OTP would allow the Roman Empire to communicate with perfect secrecy. I could very well be overestimating how important this was for them, but it seems to me like it would lead to a rather large change given that more secret messages could be sent between two parties without needing to trust the messenger. It could have major ramifications. [Answer] The same problems that a normal one time pad face would be faced by our hypothetical Caesar. Namely, if you want to send me a message, I need to have: 1. A one time pad at least as long as your message (or, if we're willing to settle for a shorter cipher, as many ciphers as you have messages) 2. Received every message you've sent me up until your current one (and both of us destroying pads once they've been used) 3. Successfully hidden my one time pad from the enemy This creates a tricky situation. If I run out of pad, you can't send me more messages without somehow getting me a new pad. If a message gets intercepted, you need to somehow figure that out and tell me how much I need to increment by. We can get around this by, say, discarding a page every day or numbering the pads, but this means a lot more pad and leads into the third problem: I need to hide at least twice as many documents as you're sending. To decode a letter I need the letter and its key. That's two documents I could be caught with and executed for, and two documents that might be intercepted, either of which would ruin the message. With all that said, it probably wouldn't see a great deal of use outside of very special circumstances where it's better to lose the information outright rather than risk discovery- internal affairs rather than wars. A regional governor has perverse tastes, and if discovered the province could revolt. Still the agent needs to inform their superior so it can be handled discreetly, so the one time pad is used. In crisis situations they probably wouldn't be used - if the byzantine generals are trying to coordinate, losing the critical message to a messenger being intercepted is worse than the defenders getting hold of the plan. Of note, the message loss problem can be solved if I retain used pads to decode corrupted messages and cope with messages arriving out of order, but this then becomes more of a codebook than a one time pad. For the circumstances we would want to use a one time pad (ie. where we would prefer for nobody to know the message over the proverbial Eve knowing it) it represents something of an unwelcome risk. [Answer] I'll go with "No effect". The value of modern encryption lies with our use of telecommunications. Our messages can generally be intercepted by hostile agents without any real method to prevent or detect that. This creates a need for a method to secure the actual communications independent of the medium being insecure. The Romans did not have that. Their messages were carried by human couriers, who would guard the messages. The messages themselves would be physical objects secured against tampering with seals. Provisions would be made to destroy the messages, if capture seemed imminent. A system like that is as secure as the people involved. No system for communicating between people can improve on that. The best you can do is to minimize the number of people with access to the messages. Securing the physical messages against tampering and using guards actually works here. You do not need to be able to read the message or have any knowledge of codes used to guard or deliver it. In fact, a more complex encryption such as OTP would be less secure. Somebody needs to write those pads, they need to be transported to correct location and then stored and secured there. And the actual encryption and decryption would be labor intensive enough to probably require additional people to deal with it. People who can be bribed or just captured and tortured. And without the pads, messages are useless, so bribing any of the people involved with the pads to sabotage them will be quite devastating. And if people start to believe the system is secure, the security will suffer. [Enigma](https://en.wikipedia.org/wiki/Enigma_machine) taught us that. By contrast a very simple cipher such as the one Caesar actually used can be memorized and decoded directly by the recipient. While the added security is fairly small, it comes without added complexity or vulnerability. And with the constant presence of servants, slaves, and guards a cipher that simply stops people reading over your shoulder does have real value. And OTP cannot do that. It cannot be read directly by most people. You have to decode it and then read it. Which means a physical copy of the decoded plain text needs to exist during both encoding and decoding. The bottom line is that for the needs the Romans actually had the Caesar cipher is actually superior to one time pad. Which kind of makes sense, the ancient world had some extremely smart people and Caesar was fairly well educated. If he had wanted a code that is harder to break, he would have been able to get one. [Answer] As mentioned by others, a full-blown OTP is unpractical. However, [there‚Äôs a middle way](https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher), invented by [Blaise de Vigen√®re](https://en.wikipedia.org/wiki/Blaise_de_Vigen%C3%A8re) in the XVIth century in France. The Vigen√®re cypher [is crackable using modern cryptanalysis](https://en.wikipedia.org/wiki/Friedrich_Kasiski) but for a very long time it proved formidable. If it had been invented ‚Äî and used ‚Äî a few centuries earlier, this could have changed the course of history. I shan‚Äôt enumerate all historical events that relied on broken private communication (for a fun account, I recommend [The Code Book](https://en.wikipedia.org/wiki/The_Code_Book) by Simon Singh), and I can‚Äôt speculate about the influence that better cypher would have had. What‚Äôs interesting is that even after the invention of the Vigen√®re cypher, [strictly inferior systems](https://en.wikipedia.org/wiki/Great_Cipher) remained in widespread use, even for communications of the utmost importance and secrecy. Of course these were soon broken. Throughout history, there‚Äôs been an arms race between cryptographer and cryptanalyst. Whenever a stronger cryptography was developed (and used), the onus was on the attacker to break it. And when a cypher was broken, there was need to develop better cryptography. I therefore think that the biggest influence, if Caesar had known about the Vigen√®re cypher, would have been on the development of modern mathematics and statistics: attackers would have spent more time thinking about how to analyse text to break the cypher. And, in doing so, they would by necessity have to invent methods of working with discrete distributions of events. Modern statistics was almost exclusively developed in the last 200 years. Recently its use has become ubiquitous and powerful (data science? statistics. AI? statistics. ‚Ä¶¬†the list goes on). Now imagine modern statistical tools had been invented 1000 years earlier. There‚Äôs a big caveat in my speculation: even without ‚Äúbig data‚Äù, modern statistics relies heavily on computers for tabulation and computation. Their use is severely curtailed lacking these mechanical aids. Nevertheless, statistical thinking would have had a drastic effect on the development of science and technology. [Answer] I think OTP would be perfectly useless. Gauls were barely literate. The odds of them deploying sophisticated techniques were exactly zero. It's quite possible that any pad would have make the message less secure by introducing an extra point of failure. [Answer] I would go with no effect -- unless you tweak the scenario. There is no intrinsic reason why the Roman Empire couldn't have had a functioning [optical telegraph](https://en.wikipedia.org/wiki/Semaphore_line) system connecting Rome with points several hundred miles away. Such optical communication would be vulnerable to interception so would require some form of encryption to function effectively. In an alternative history, the security of such optical communication could play a role (e.g. Roman troops ambushed because an attacker knew their route before hand). A one time pad seems to be overkill, but as others have pointed out it something like a Vigen√®re cipher would have given reasonable security at the time. [Answer] 1. No effect. This technique has very limited use given that all communication in that age was via courier. The message and the key would both have to be sent to the same recipient by separate runners, either spaced apart or taking different runners. At best, it would take more time. At worst, if only the message or only the key was delivered, either is useless without the either, resulting in breakdown of command communication. Information security at the age when information travels at the speed of a horse is a very minute factor - especially given the literacy rate at that time period. 2. Even less of an effect. A one-time pad is "unbreakable" when used with bits. When used with words and sentences, it is literally as complex as any other substitution cipher - sentences and words have a determinable structure. Not to mention the message and the pad have to have the same number of characters, meaning it can only be used once in an age of limited communication resources - and once again, an age when most people cannot read, much less encrypt and decrypt messages. The method would far, far out-pace the means. ]
[Question] [ I have a (medieval non-fantasy but fictional world) setting in which several kingdoms have royally sponsored duellists that will represent the kingdom in international disputes. As this isn’t a particularly realistic concept, I have devised the following scenario: We have a few kingdoms on a large peninsula, which is divided from the mainland by a mountain chain (think a larger Iberian peninsula). The mountains are not impassable, but pose a significant obstacle. Beyond the mountains is a relatively large empire that’s known to have absorbed several smaller nations. The kingdoms behind the mountain chain have remained independent largely by relying on this natural defence making an invasion much more costly and easier to defend than is worth trying for. During the year of a bad harvest there’s a conflict between the two largest kingdoms, at least one of which borders the mountains. The conflict is important enough to go to war under normal circumstances, but with the food being scarce it’s a really bad idea to take all the grown men away from the fieldwork. Furthermore, the war and famine combined would likely weaken the kingdoms so much that an invasion from beyond the mountains would now have a chance of success, something none of the kingdoms want to risk. We’ll assume that the nature of the conflict doesn’t allow to just wait for 2-3 years before going to war. In that situation the kings agree to each appoint a representative to duel in their name with the winner receiving a favourable resolution of the conflict and a one-year treaty of nonaggression being signed. They fight, one wins and one loses and both nations keep to their word. This does not abolish war and field battles in the future, but it leads to the establishment of a tradition in which conflicts that aren’t quite important enough for all-out war are resolved via duels, thus giving monarchs an incentive to find and sponsor the most skilled fencers in their respective nations (and possibly entice those of others to switch sides). Is this close enough to making sense to trigger suspension of disbelief or is it completely impossible or ridiculous? [Answer] It was a common trope in Roman and Greek mythology to the point of earning a name: [Champion Warfare](https://en.wikipedia.org/wiki/Champion_warfare) (and [single combat](https://en.wikipedia.org/wiki/Single_combat)). If your kingdoms have a caste of professional warriors (like knights, samurai or [berserkers](https://youtu.be/PBUGQkpk3RE?t=352)), it doesn't break the suspension of disbelief. [Answer] I also think you have the problem of War being the last resort of losers. To counter that, we can make War expensive in a different way: Form (as a given in the story) an Alliance of Kingdoms, not with authority over any individual King, but promising mutual defense against invasion by each other. Part of their alternative to war is to settle disputes between Kingdoms by a contest of champions. If any King refuses to honor the outcome of a contest of champions; their kingdom is forfeit and ALL the other Kings are honor bound to band together, invade and divide the spoils equally, putting the offending King to death. All such disputes are presented to the Alliance, and the contest of champions is conducted in their arena, with the two Kings in (very comfortable) custody. The winner is determined by the Alliance, in case of complications (say both duelists end up dead). Once the decision is made, the losing King must give his orders (for withdrawal, payment, etc) and shall remain in (very comfortable) custody until they are carried out. To be fair, you have the problem of a King with the world's best duelist just invading territories and taking what he pleases, always depending on his Champion to defend his thievery. To counter that, require Kings to show up to the duel with ten champions each. The Alliance can determine who they believe is the more wronged King: The one wronged gets to pick his own champion from his Ten, and can then exclude any one of his opponent's champions, and the one to fight will be selected by lottery from the remaining nine. [Answer] I think this makes sense, though I don't know of any real-world examples, and it would sound more realistic if instead of "kingdoms" these were better characterized as tribes or clans. Since this is a fictional world, there's no need to refer to political entities using names already laden with real-life historical connotations. What that means: I'm not sure a European medieval king-like ruler would leave territorial disputes with foreigners in the hands of a champion, but I could see this system working where people already see themselves as part of a larger whole, say, a loose federation of tribes or clans with a recognized common ancestry and common customs, rather than kingdoms/nations. Local interests will keep them apart and selfish leaders will emerge but they will have to be more open to such arrangements as you propose. [Answer] I would like to point out that if I challenge you to a duel, you as the challenged have the right to choose the venue and the weapons. Abraham Lincoln semi-apocryphally agreed to a duel, with his weapons being broadswords at 2 paces (Abe, unlike his challenger, had long arms). Here is where this gets fun. Typically the champion is some Achillesesque ace warrior and the duel is a battle. But not necessarily. My country accuses yours to a duel. You say yes, and the ensuing duel could be with any weapon, or maybe not even a weapon - a wrestling match, or a game of billiards, or any other sort of contest. Then I must scramble to find a champion who can represent my side in the contest. I especially like this as an ad hoc Olympics, with the events days in advance and the contestants given even less notice. "Madam, it has come to the attention of the King that you have great skill in making pies. And your country needs you." [Answer] I'd say that's quite a sensible system: * Even without the famine, this would prevent the deaths of thousands of soldiers on both sides, ensuring that both kingdoms remain at full fighting strength in case the Empire Beyond the Mountains ever comes a-calling. * Wars can drag on for years. The Hundred Years' War wasn't exactly 100 years long, but it did go on for decades. A duel could be organized within weeks and fought in a matter of minutes. * Related to the above, wars are really, really expensive in financial terms. Medieval rulers often had to pay for them by increasing taxes, which was never a very popular move among their subjects. Duels are much cheaper, and would therefore be a much more attractive option, especially for smaller-scale conflicts where it's really not worth bankrupting the country. * A fair one-on-one duel creates a level playing field. No large-scale tactical trickery, no taking advantage of the terrain, no overwhelming the enemy with superior numbers. It all comes down to the respective training, equipment, and fighting skills of just two people. There would be far less scope for excuses if you lost. You'd just have to suck it up and accept the outcome. [Answer] While champion warfare was mentioned, it never was the method to determine a victor, merely a way to gain morale advantage before upcoming battle. As it stands, I don't find it quite plausible that no ruler will abuse reluctance of others to go to war. Politics were always a messy business, not a matter of chivalry. And if you are going to backstab a neighbour instead of honouring duel results, you are going do it in a way that puts you at advantage, without any lengthy wars. However, you have what would make it much more believable with some adjustment: the Empire. If mountains aren't quite high enough to prevent it dealing with any one kingdom, then all kingdoms could've entered a loose defensive confederation of sorts. Something like the Holy Roman Empire of their own, but without the Emperor. With a Diet for passing confederation-wide edicts and laws. Of course, still resolving conflicts with a duel wouldn't occur right from the start, there wouldn't be enough trust between participants yet. But it can be passed by the Diet later on as a way of resolving conflicts without being too detrimental to the overall defensive capability. And since now this is the will of all the kingdoms, not honouring the result of a conflict resolution would put make a lot of people angry with you, not just your victim. [Answer] No, it isn't. By assumption, your kingdoms are souvereign states with no higher authority above them (like the Holy Roman Empire or in modern times some International Courts all parties accept). So why should a kingdom accept concessions that it has to make after a lost war just because of a lost duel? The looser of the duel just will not accept this fact and war will break out anyway. Remember the story of the three Roman brethren fighting three enemies of Rome? The losers waged war (and lost it, too). [Answer] I think that the dispute shouldn't have any materialistic value. The winner and the loser of the duel should only gain or lose honor and prestige. Due to the fact that they are both vulnerable nations and know that if one of them attacks then the "Empire beyond the mountain" will see that as an opportunity to expand. Both of the nations know that even if they lose, they have no reason to comply with the winner's demands, because the winner cannot do anything to enforce them. (The loser is in a more favorable position, because it is always easier to defend than to attack). [Answer] Think of it as a regional association of states which have all surrendered some of their sovereign powers to a supranational court. Except that this court uses trial by combat. * An agreement to take all quarrels to a court (and to abide by the decisions even when they go against your nation) is quite common these days. Getting out of the agreement might be an option, but the costs of leaving probably outweigh the costs of accepting any one unfavorable decision. As long as there are benefits in the long run, most nations stay in. Think EU, NAFTA, etc. * Trial by combat is nothing a modern nation would accept, but that's your fantasy angle. So what you need is an agreement, by the rulers and those citizens who matter, that (a) cooperation on the peninsula is worth something and (b) those wars are just business, no hard feelings. Win some, loose some. Maybe in five years your champion will be more lucky. [Answer] I'd say it strains credulity. First, let's go over why champion warfare doesn't work in general: There is a conflict between two nations severe enough that they would want to go to war against each other. You have two options for the scenario: 1. One aggressor nation against someone unwilling to give concessions. 2. There is bad blood between the two nations and they want to hurt each other. If it is the second option, would single combat be satisfying to the belligerents? Doubtful. If it is the first option, why would either side agree to champion warfare? If I am the aggressor, I desperately want something from you. That's why I want to go to war to get it in the first place. If I am strong enough to take it, why would I risk not getting it by going mano a mano? If I am not strong enough to take it, why would the other side risk losing it? Now let's look at the wrinkle you've created: > > During the year of a bad harvest there’s a conflict between the two > largest kingdoms, at least one of which borders the mountains. The > conflict is important enough to go to war under normal circumstances, > but with the food being scarce it’s a really bad idea to take all the > grown men away from the fieldwork. Furthermore, the war and famine > combined would likely weaken the kingdoms so much that an invasion > from beyond the mountains would now have a chance of success, > something none of the kingdoms want to risk. We’ll assume that the > nature of the conflict doesn’t allow to just wait for 2-3 years before > going to war. > > > I'd say that this doesn't alleviate that problem. A famine makes the stronger side stronger and the weaker side weaker. If the aggressor is stronger, as you kill their guys and land, you steal all the food. If the defender is stronger, then the attack is weakened and sieges are unlikely. As for the aspect of the third superpower over the mountain, there's an old saying that the best place to defend your country is in someone elses. Every other smaller nation on the peninsula is going to want the mountain facing one to be strong militarily. If they say "We are not doing single combat, we are going to war. You other nations can either join us and quickly and easily crush our opponents, or we will bleed ourselves dry and you can can all be crushed by the barbarians over the hills." Can one superpower one your peninsula stand up to the other one + all the smaller nations? If not, then the aggressor can get what they want this way without risking war or single combat. --- Instead, maybe make war easier, but still costly. IMO, you want it to be very expensive for the ruling class but not be an existential threat. Existential threat means that everyone will band together either to make sure both sides don't fight or that one side ends it quickly without much loss. You could go to war, but, your nobles will have a better life if you don't. The area between the two nations simply has the best vineyards. They'd be decimated by any military action that wasn't a beatdown. Now there is pro and cons to the single combat. I can risk losing what I want with the single combat, or I can guarantee to lose something else I want with the war. Both leaders have to be saying to themselves "If I lose the combat, I'll lose something small. If I win the war, I'll lose something bigger. Either way, no one else will care, so there's no way for me to manipulate the odds." [Answer] This seems similar enough to the origin/purpose of the Olympic games. You have several small societies that need cohesion, cooperation and military resource conservation due to external threats/pressure. The smaller states won't federalise or submit to rule under another that they consider equal/superior to, so to avoid conflict and escalation they use games. Over time the tournaments could get ritualised by the dominant religious body and superstition will ensure the games still continue when regular diplomacy breaks down (see Peloponnesian wars). This is only one step from actually accepting demands or reparations as the result, though fines and rewards were given for victory and rules violations in the Olympics, so it doesn't seem unfeasible. Additionally, states would probably regulate their demands of the result of a victory acknowledging that it wasn't equivalent of a total military victory. Edit: Also consider in the Olympics: US wins, pretty much every time. Population and GDP (spare money for sports) plays a massive factor. This would be even more extreme factoring in buying sportspeople. [Answer] It fits when the primary goal of the nobility is not tangible gains, but status. If you have a society of nobles, and the big thing they actually care about is what everyone thinks of them (with things like money and lands being mostly useful in acquiring and maintaining status) then it's entirely possible for warfare to go from army vs army to champion vs champion to just duels (possibly with small military units standing around for backup martial demonstrations, to make sure that the forms are followed properly, and to serve as audience). [Answer] The two kingdoms are equally matched, with equivalent technology levels, weaponry, and tactics. A total war between them would be very costly, and would likely cause both kingdoms to be weakened to the point that the kingdom over the mountains could easily sweep in and destroy them. If the conflict is over something like a resource (a town, river, mine, etc.), it makes sense to solve it in a way that preserves the power of the kingdoms. Can we suspend disbelief? Well, yes. This isn't a new idea. [Single Combat](https://en.wikipedia.org/wiki/Single_combat) was a [very](https://en.wikipedia.org/wiki/Mard_o_mard) common feature in ancient combat among many diverse peoples such as the Greek, Egyptian, Hindus, Romans, Irish, and Jews just to name a few. The reason is as stated above. War is destructive and costly. If the cost of war is too high, one looks for a cheaper alterative. The key is equally matched opponents. The grim logic determines that if one side feels like they have the advantage in numbers, weapons or tactics, they would not submit to single combat. Why chance on losing a fair fight when you can win the unfair fight? Rome would not do a single combat with a much weaker state. They'd just sweep in and destroy them. [Answer] Not in a "You have offended my honor glove smack sense, but the cold war was rife with Wars by Proxy (Vietnam, Soviet-Afgan War (Afgan combatants were funded by the US), Gulf War (Iraq fieled Soviet Union equipment against NATO forces... despite the Soviet Union having fallen, many saw it as a test of what ground combat would have looked like in an actual open war)). These are ideal as neither sponsor nation was keen on open war due to the fact that it was a no win scenrario, so they engaged in patronage of smaller countries in conflicts to bolster their favored side... when the other country got wind, they would supply the opposing side to stop the side that got the initial funding... sometimes this was a deal with the devil as the opposing side had little ideoligcally in common with their patron beyond a common enemy (The United States is slowly going away from that because it's boiling down to arming people who we don't agree with to kill other people who don't agree with us). The advantage to this is that these wars initially cost less and provide a great proving ground for weapons they intend to field in actual combat. The country and conflict offer no territorial game and thus, losing while showing off your equipment allows you to better compensate for a real war and didn't devestate your own nation. Considering the nature of Nuclear War fare, neither the Soviet Union nor the United States were willing to break out the nukes for nothing less than a direct war. On an even more peaceful front, you can have an X-Race where X is any number of national achievements (Space-Race, Naval-Race, Arms-Race) ect. Fun fact, the Space Race was less about landing a man on the moon, and more about singing "My Missle is better yours is. My Missle can fly twice as far as yours does." For a more serious explination, it was "How do you show your nuclear missel is a threat without a nuclear explosion and a classified test?" Simple, claim it's a rocket ship and you're sending men to the moon, then take one of your nuclear missles, take off the warhead, put on a tin can that a man can breathe in while it is in space, and shoot the thing into the sky and land it. It tests all the functions of the nuclear missle without the big boom. In fact, it wasn't until the nearly a decade into the Space Race that the first purpose built space rocket (designed to carry people into space first and for most), the Saturn V, was introduced to the world. If done properly (think the Star Wars defense system of the 1980s) a prolonged arms race could actually financially ruin a nation in their attempt to keep up (The threat of Star Wars was such that the Soviets spent themselves out of existance trying to keep up with the United States... unaware that the United States was just as far behind in Star Wars as the USSR was... they just lied... prior to that, the Russians got the United States to invest heavily into building more nukes by stratigically making the bomber and later missle gap seem like a reality, when in fact, it's hard to say the USSR ever had more nuclear delivery systems than the United States... But those constant May Day parade fly overs in Moscow freaked out the DoD, who were unaware that the Soviets were just turning the planes around off camera and flying back over the parade route for multiple passes.). Even something like Modern Day Olympic games were ways for nations that hate each other to fight without war. Again, Soviets and The United States... basically, any time the Soviets and the United States met in national capacity, they pretty much shouted "It's on like Donkey Kong!" Anything to avoid calling bluffs on Mutually Assured Destruction policies. [Answer] Point of war is NOT to win (or die) if fair competition, defending your country. Point of war to gain any unfair advantage you can get, and make the other guys die defending theirs. ]
[Question] [ [Thorium power plants](https://en.wikipedia.org/wiki/Thorium-based_nuclear_power) were a thing that was researched and ultimately abandoned; however, for all intents and purposes, it's safer than any power source we have today. In our timeline, the first such reactor was built in 1965, but it was a proof of concept only, and all thorium reactors were shut down in 1973. Meanwhile, uranium nuclear reactors have been commercially used since 1954. What are plausible conditions that would create a situation where thorium power is used to supply at least 1/2 of a major nation's energy needs? Currently uranium-based nuclear energy in the US provides 1/5 of its total needs, while France is almost at 3/4, so we would need to: * Increase the share of nuclear power compared to alternatives (fossil, renewable) * Increase the share of thorium power plants compared to uranium ones Let's say the 50% goal should be achieved by 2016, meaning that it may be necessary to push the discovery of nuclear power further back through some events. [Answer] The two primary drivers of Uranium fission reactors are the need for fissile material for nuclear weapons, and the ability to make compact reactors for powering nuclear submarines. Point two also explains why light water reactors are the primary design of existing reactors in the United States; they all evolved from the engineering knowledge and experience gained by building nuclear submarines in the early 1960's. If WWII had ended with both Nazi Germany and the USSR having collapsed (perhaps the Germans actually won the invasion of the USSR in 1941 to the extent that the Communist government and organizing structures had been destroyed), then the United States would not feel an overwhelming need to push the production of fissile material for bombs and triggers (in practice, Plutonium bred from fission reactors), nor the desire for compact, high energy reactors for submarines. With fewer incentives to follow a particular path, US nuclear engineers could have worked on a much broader range of reactor designs. Thorium was an obvious choice for civilian power reactors since Thorium is cheap and abundant, and there would be no obvious pressures, pre existing pools of resources and talent or sunk costs to swing the balance towards light water reactors. [Answer] ## Don't have a Cold-War. The United States had to choose a direction in which it would go in terms of nuclear research: Thorium, or Uranium. Only one of these had the corollary benefit of making bigger bombs. Guess which one got funding from the Defense budget to keep ahead of those pesky Communist Russians? [Answer] Thorium people have not stopped their activity, but they suffer from financing issues. If the question is - "what if history turned another way" - then Reagan could possibly be your point of divergence, as it was a political decision to shut down the process. It had probably bunch of aspects behind the scene, having plutonium sure one of them. Efficient burning was not the goal, but getting specific types of isotopes was. So a high energy demand, successful breakthroughs in problems, the possibility to make Plutonium, some accidents with solid reactors at early stages like Chernobyl to build public resistance for those types of reactors (so it means actually some serious errors in process of developing nuclear reactors, to be too optimistic and go big too soon) So significant negative pressure could limit solid reactors to military goals only. And military played significant role in developing those reactor for their purposes. [World's First NUCLEAR SALT REACTOR - Documentary Films](https://www.youtube.com/watch?v=xIDytUCRtTA) pretty interesting history kind video. (they blame Reagan, saying that if he would be more familiar with technology he could decide other way) Positive factors which could keep a molten salt reactor afloat could include space program like moon base, mars base. Salt reactor, one of reason to start that program was wish of military to use it in aircraft, and conventional reactor was not capable to do that, but a molten salt reactor could in theory (even if the creator did not believe that it would work in a plane) to be used there. For use in space, it has advantages too, one advantage being the more efficient use of fuel without expensive and technology intensive processes to recover fuel, to reassemble fuel rods. A lower reactor mass and simpler management are also very significant advantages for use in space. It is also much easier to deliver the initial fuel - because of how it is packed. There is much less danger in the case of a mishap during launch, because of how it can be packed. It is easier to work with thorium as a main fuel source. There are also pretty significant amounts of it on the [surface on the moon](https://en.wikipedia.org/wiki/File:Lunar_Thorium_concentrations.jpg) (12 ppm is about 70 tonnes per million tonnes of dust, thorium is ca 230 atomic mass, average for moon ca 30 atomic mass, so it is 12 \* 7 tonnes per million, my rough estimation, even in the unlikely case that there are no concentrated ores) According to fast [link](https://www.withouthotair.com/c24/page_166.shtml) * Thorium reactors deliver 3.6 billion kWh of heat per ton of thorium, which implies that a 1 GW reactor requires about 6 tons of thorium per year, assuming its generators are 40% efficient. So it would be enough for a 10GW reactor, which will generate 315 GJ of electricity per tonne of ore. On the moon efficiency can be higher overnight, just as a note. Glass production uses 9GJ per tonne of product (mostly for melting), Aluminum production uses 54 GJ per tonne (because of the energy requirements of reduction of Al2O3 into Al). So you basically can melt it (ore) all down, reduce all stuff to pure metals and gases by electricity and it will be something like 20% of what you will produce after extracting the thorium. Not saying it is the way to do, but why not if you need Iron, Aluminum, and Titanium - which are present on the moon: [some NASA thoughts about Al on the moon](http://settlement.arc.nasa.gov/spaceres/V-4.html) So a strong lunar program could be one of the factors in favor of molten salt reactors. One of the factors involved in solid reactors being preferred is investments from the military, they wanted them for a bunch of reasons. Thorium reactors for a lunar base are an excellent choice, so they may have happened during the Appolo era, if there were other factors enabling moon base. This will aid progress in other areas, not just nuclear related problems, and could be one of the factors that could open perspectives for this technology to be more attractive, or enough attractive to pour money into it, and that is actually all it needed at that time. So it may be not a big stretch, that history of molton salt reactors could be different. P.S. as people have mentioned the Russians, so will I. Greater successes for their moon program could be also one of the factors supporting an expanded US moon program, without collapsing it. So moon base race could be an enabling factor too. # Note read in case factual incorrectness feeling. disclaimerTM, do not build it at homeTM, make your own research before buildingTM, call me if u didTM In this answer I rather project words of other, who are optimistic about thorium reactors and who thinks that problems can be solved. Also it is not mention explicitly, answer keep in mind one particular type of possible types of Thorium reactors, molten salt with in situ utilization. Packing benefits assumes packing fuel pellets, like in [Pebble bed reactor](https://en.wikipedia.org/wiki/Pebble_bed_reactor), and relays on possible advantages dividing fuel in to small packages, encapsulating them in robust shell which can withstand fall from orbit if needed, where shell may be actually non radioactive part of future fuel(same thorium actually). It may be non radioactive (as Thorium non radioactive, not as completely non radioactive) in case of some kind of [ADS(accelerator-driven system)](https://en.wikipedia.org/wiki/Energy_amplifier) as starter for whole process. There is difference with uranium rods, which I think can be exploited to our advantage. Each reactor development includes lot of work behind the scene. This is complex work, which includes solving non obvious for the public or outsiders set of problems. If everything would be easy and simple, then it would be solved in the past, and we would not have question may or may not it to be solved. It wasn't, and question is valid. Simplicity of main concept, does not mean that solution will be simple, it does not mean it is possible at all, at least at some technological level, which looks sufficient for solving that problem, but in fact, it is not sufficient and needs involving of more advanced technologies, to make it working or just working. Some examples for better illustration: Examples of such, which comes in my mind right now, as example knife. It is very old design, stone age old, but really good results where achieved after work with metal became more usual practice. Another relatively simple idea as [Space Elevator](https://en.wikipedia.org/wiki/Space_elevator), with less obvious problem not exactly but like - to have easy access to space, u have lift huge amount of stuff or build that in space - both looks like easy access to space help here. Obscure/contrast it a bit more - to get easy access, u better have easy access. Even it almost technically possible to build such cable as just rope, u need more advanced rocket systems, or another and better launch technology it is possible, but would u need elevator then? 3He as fuel in thermonuclear reactor there are [objections](http://cds.cern.ch/record/1055767/files/CM-PRS00002036.pdf) based on speed of reactions which would have place in such reactor. [Launch loop](https://en.wikipedia.org/wiki/Launch_loop) where main problem is reliability at current level of tech. So there are interesting and promising things which looking good, but do not work at current tech level, for understandable reasons. How advanced we should be to solve them, who knows? Those who knows about thorium dividing in 2 categories believers and non believers, but none of them can prove that other side is wrong. One side not failed yet, but also do not have great success. Other side can point those 2 facts, but can't state it is not possible, exactly because of those 2 facts, but they try to make their reactors better, just in case(for reasons of waste). So this race is not ended yet. # Interesting links play scientists, investigate isotopes chains - [periodictable.com, isotopes, Th](http://periodictable.com/Isotopes/090.233/index.full.html) Thorium optimists site [energyfromthorium.com](http://energyfromthorium.com), they recommend this video 2h video ["NASA" - Thorium remix 2016](https://www.youtube.com/watch?v=0BybPPIMuQQ) to watch, I expect it to be at least interesting, but have not watched it yet. [Thorium fuel cycle](https://en.wikipedia.org/wiki/Thorium_fuel_cycle), and specially "List of thorium-fuelled reactors" Molten salt reactor concepts in general, <https://en.wikipedia.org/wiki/Molten_salt_reactor> [Answer] Just a practical way of harnessing its power. Thorium power-plants need to go a long way it before being commercially interesting. Not because Thorium is expensive or hard to use, but because we don't really have a easy way to tap on its power — yet. People are driven by necessities. If coal and oil (the "easy" power sources) are getting rarer and more expensive, people will turn to other, "harder to use" energy sources, like nuclear power, hydroelectric or wind-based. However, as you use something, you learn its limitations. This provides a good base to future research, which in turn makes it easier to use as new, more efficient stuff is discovered about that something. It was the same with computers, with the Architecture change — people didn't swap to x64 right away because it was easier to keep using x86, even if x64 was way better. Nowadays, you only find x86 computers on some really outdated offices and on a few grandfather's houses. Heck, it's HARD to find x86 machines anymore! So, yeah. It's mostly time. Once you find a way to make use of Thorium, just keep up researching and making it easier to use, and eventually people will embrace it. [Answer] The requirements for developed theorium reactors are not that tough: easy access to thorium, limited access to uranium and other sources of power and no incentive to develop a nuclear arsenal (and this last point is perhaps not even true; there are some that claim that the uranium 233 that is the actual fuel in a thorium-based cycle is viable as bomb material). Thorium is today seen as a less viable choice because it would need different reactor technology than what is used in most of the world to be most effective. However, this is not in itself a major problem. The Soviet union, Canada and the UK uses or has used reactor designs that significantly differ from the US-designed LWRs. I will give you one possible scenario: Sweden had it's own program for building heavy water reactors, with uranium mined in Sweden (Sweden has a lot of uranium, but not very concentrated). Had the large thorium deposits found in Norway been on the other side of the border, it is possible it would have choosen designs based on thorium instead, and gotten so far before the non-proliferation treaty that it would have decided to not buy american LWR designs but instead continue with the domestic design. At the peak, Sweden's reactors produced slightly less than half of the electricity used, so that requirement is not much of a stretch. [Answer] # Thorium is not a practical nuclear fuel Uranium contains 0.72% by mass of U-235, which is capable of sustaining a fission chain reaction, yet it does not produce high radiation by itself. So a block of Uranium can be refined to 3-4% U-235 by mass. At this point, it can sustain a fission chain reaction, and can be used for fuel. The process by which uranium is enriched is by attaching Uranium atoms to Florine atoms to create Uranium Hexaflouride gas. This is then spun in a centrifuge; the heavier U-238 atoms are separated from the lighter U-235 atoms. Once enough of the U-238 is removed, the UH$\_6$ gas is converted to UO$\_2$ for use in reactors. The excess U-238 becomes depleted uranium. While the UH$\_6$ gas is highly toxic, the radiation exposure of people and equipment from this process is negligible. Almost all reactors in the world (~90%) use this process to generate power. The remaining 10% are Pressurized Heavy Water Reactors. These reactors do not use enriched Uranium, but rely on heavy water (D%\_2$O). Heavy water does not absorb neutrons as readily as regular water; it thus reflects more neutrons back into uranium fuel as it moderates and allows natural Uranium to become fissile. The trade off for the reduced fuel cost of natural Uranium is the high costs of heavy water and reduced energy density of the fuel. A Thorium reactor would work on a different principle altogether. It would 'breed' productive U-233 fuel from Th-232. The U-233 must then be removed from the thorium and concentrated to use as fuel for the reactor. Once a U-233 reactor is set up, Th-232 can be inserted into it to breed more U-233. The problem with U-233 comes with separating it from the Thorium. This can be done chemically; since Th and U are different elememnts, they react with different chemicals making it easy to dissolve one but not the other. However, a byproduct of breeding U-233 is U-232, which is extremely radioactive, having an extended decay chain that releases multiple MeV gammas per atom that decays. That is the showstopper. Remember, that enrichment of U-235 takes place from a material whose radiation level is barely above background. Instead, when trying to separate fissile material from Thorium, you are trying to remove fissile material from highly radioactive nuclear waste, and within the usable product is more highly radioactive nuclear waste. High energy gammas require the separation process be done in a sealed, shielded room; but they also will disrupt electronics in that room. The damage to electronics is key; if electronics (i.e. robots) are damaged by gamma radiation, the entire process must be stopped and radiation levels allowed to drop until equipment can be replaced or repairs made. These work stoppages would make the Thorium fuel cycle uneconomic. The only alternative is to expose workers to high radiation levels to limit reliance on robots. Radiation exposure of that level is obviously not feasible in Western countries, as the liability to lawsuits of nuclear power companies would be prohibitive. Fissile material cannot be economically refined from Thorium due to high radiation levels of the 'bred' Thorium and the mixture of highly radioactive U-232 into the U-233 fuel. An engineering solution to this may eventually be possible, but currently there is no way to use Thorium as a fuel without accepting high levels of radiation to workers. ]
[Question] [ A classic trope in media is the country that is [constantly having a revolution](https://tvtropes.org/pmwiki/pmwiki.php/Main/RevolvingDoorRevolution), with the logical extreme being a geographical region where any map older than a year is woefully out of date as new nations rise, borders shift, old nations fall and more coups are had than courses at the following inaugural banquets. However, I want to be able to explain how this region manages to stay so politically active when every settlement in the area would have lost their entire population of 20-40 year olds after about ten years. So, how does a reasonably large geographical area (at least a moderate country, preferably larger) sustain regular and drastic shifts in power (the more rapid the better) over a long period of time (at least living memory)? [Answer] *You should study Banana Republics*** > > In political science, the term banana republic describes a politically unstable country with an economy dependent upon the exportation of a limited-resource product, such as bananas or minerals. In 1901, the American author O. Henry coined the term to describe Honduras and neighbouring countries under economic exploitation by U.S. corporations, such as the United Fruit Company. Typically, a banana republic has a society of extremely stratified social classes, usually a large impoverished working class and a ruling class plutocracy, composed of the business, political, and military elites of that society. The ruling class controls the primary sector of the economy by way of the exploitation of labour; thus, the term banana republic is a pejorative descriptor for a servile dictatorship that abets and supports, for kickbacks, the exploitation of large-scale plantation agriculture, especially banana cultivation.A banana republic is a country with an economy of state capitalism, whereby the country is operated as a private commercial enterprise for the exclusive profit of the ruling class. Such exploitation is enabled by collusion between the state and favored economic monopolies, in which the profit, derived from the private exploitation of public lands, is private property, while the debts incurred thereby are the financial responsibility of the public treasury. Such an imbalanced economy remains limited by the uneven economic development of town and country, and usually reduces the national currency into devalued banknotes (paper money), rendering the country ineligible for international development credit. ([Source](https://en.wikipedia.org/wiki/Banana_republic)) > > > > > Banana Republics are unstable because... * A rigid class system guarantees the labor force is always impoverished. * The elite ruling class includes political and military leaders who are kept in power by external businesses. In the case that a political/military leader happens to stage a coup and take control, they cannot maintain that control without the benefit of external businesses. * External businesses are required (OK, preferred) because they never have a ruling interest in the country nor have incentive to humanize the labor force. Unlike the governments of other countries, which can be influenced more by their own populations, businesses are frequently capable of acting without any kind of independent oversight. NOTE #1 While there are still many instances of Banana Republics in the world today (business will always try to capitalize on cheap labor), the more technologically advanced the world (think "fast communication and cheap pictures/video"), the easier it is for grass-roots activists to enact change that limits the influence of business. So, while Banana Republics still exist today, it's nothing like it was in their heyday of the 1900s. NOTE #2 It is possible for governments to do this, although Hollywood makes it look simpler than it really is. It's almost a trope in itself that the CIA is constantly forming, supporting, and dismantling 3rd-world governments. However, while I strongly suspect that this isn't as ubiquitous as any James Bond movie would suggest, it has happened. Consider Manuel Noriega of [Panama](https://en.wikipedia.org/wiki/United_States_invasion_of_Panama) or the Marcos' of the [Philippines](https://en.wikipedia.org/wiki/Ferdinand_Marcos), both of which were supported by the U.S. until they were overthrown. Similar stories could be told about Asian countries in the 60s-70s ([Cambodia](https://en.wikipedia.org/wiki/CIA_activities_in_Cambodia), [Korea](https://en.wikipedia.org/wiki/Korean_War#Course_of_the_war), [Vietnam](https://en.wikipedia.org/wiki/1963_South_Vietnamese_coup)...) and the Cold War era. There are further examples as recent as the [2010s](https://en.wikipedia.org/wiki/United_States_involvement_in_regime_change#2010s). The point here is that the overlord (usually a business) doesn't really care who's in power so long as their interests are protected — and will often provoke changes in the government themselves to ensure their interests are protected. From the perspective of a Banana Republic, there's nothing more inconvenient than a leader who gets too greedy or grows too much of a conscience. And if you want to get a better handle on this while having a good time, track down a copy of the game "[Junta](https://en.wikipedia.org/wiki/Junta_(game))", which will do a great job of teaching you how the instability works while letting you experience your inner dictator. [Answer] Have a lot of players with similar power levels on the board: You essentially described medieval europe on steroids. Honestly not even on steroids, just with a different mentality. Combine European feudalism wth the Chinese idea of "The mandate of Heaven", which basically says that the ruler has a mandate to reign given by the heavens, however unlike in Europe where the idea was that a dynasty had it unconditionally in China if you were a shitty ruler you could lose it. How did you lose it? Well, piss off the people enough and they will try to take over. If they succeed you have lost the mandate, if they fail then clearly you're still worthy of being a ruler. In Europe disposing the monarch was an almost unthinkable action let alone the entire dynasty. Mind you it happened, but in most cases the dynasty died out naturally and somebody just wormed their way in for example by marriage if the sole heir was a female. Quite often in Europe people tried to make it look like they weren't usurping the royal family, nono you had just become a part of the royal family. This should make it socially acceptable to usurp the leader if things go too poorly. Secondly ensure everyone is sort of similar in terms of power. If one guy gets too powerful,the others team up on them, until he's dealt with or no longer an issue and then they can war with each other again. That said how advanced do you want these societies to be? If you want a modern setting with cellphones and such then you will need someplace to be stable enough to actually produce these sorts of products. Such warring states would not be capable of creating the production and supply lines, give the needed technical education,...to build them themselves. In that case you would need a external power to supply them with such tech and need a reason why that power isn't curbstomping them. Maybe the land is too poor to be bothered with or the deathtoll would be too high and/or maybe they prefer them warring wth each other as that keeps them weaker than the external power,... [Answer] how does a reasonably large geographical area (at least a moderate country, preferably larger) sustain regular and drastic shifts in power (the more rapid the better) over a long period of time (at least living memory)? Proxy wars The never ending war scenario you are describing is best exemplified by [Afghanistan](https://en.wikipedia.org/wiki/History_of_Afghanistan#Contemporary_era_(1973%E2%80%93present)) which has been embroiled in wars more or less continuously since the 1970s, leaving it the least developed country outside of sub-Saharan Africa in the real world. Initially, this was a part of the Cold War with fighters on the respective sides supported by the Soviet Union and the United States. When the Cold War waned, Saudi Arabian elites funded a new wave of proxy wars using this as a place to test run their Islamist political ideas via the Taliban against opium cartel fueled warlords loosely aligned with the "decadent" West. The nearby example of Kashmir is another example of a sustained proxy conflict. Another similar example is the [Hundred Years' War](https://en.wikipedia.org/wiki/Hundred_Years%27_War) "waged between the House of Plantagenet and its cadet House of Lancaster, rulers of the Kingdom of England, and the House of Valois over the right to rule the Kingdom of France. It was one of the most notable conflicts of the Middle Ages, in which five generations of kings from two rival dynasties fought for the throne of the largest kingdom in Western Europe." It was the primary model for the fictional Game of Thrones series of books and television adaptations of the books. A third example would be the Islamic empire's seizure of Moorish Spain followed by hundreds of years of the [Reconquista](https://www.ancient.eu/Reconquista/#:%7E:text=The%20Reconquista%20(Reconquest)%20or%20Iberian,since%20the%208th%20century%20CE.), and parallel Christian-Muslim proxy wars in the Balkans (most notable for creating Vlad the Impaler, the model for Dracula, who due to events in his life played both sides of the conflict as it suited him), and in the Crusades in the Levant. This would ebb and flow, however, as exogenous forces in the competing countries waging the proxy fights are able to devote more or less attention to the conflict. Infusions of resources from the proxy fighters keep the conflict going despite the limited capacity of the focal point of the conflict to maintain it otherwise. Climate change There have been long running, near genocidal wars from coast to coast in the African Sahel for the entire post-Colonial period. At their root, these are being driven by global warming, which is slowly pushing the Sahel ecological zone previous occupied by Muslim herders to the South into Christian/animist marginal farmers in the next ecological zone to the South (who are less flexible and mobile since they own only the land that they own and are struggling as that land becomes less viable to farm upon) as the Sahara desert expands. While particular groups in particular countries along that swath of Africa can make peace or have it imposed upon them for a little while, ultimately, it is an inevitable and existential fight between two ethnically and religiously distinct communities with different culture who have different means of food production and "business models" that are incompatible with each other and with the status quo. You can't herd and farm in the same place. This wouldn't be stable, however, because while climate change means a long term steady trend in one direction, weather inevitably shifts on short and medium term scales, so two steps in the direction of the long term change are followed by one back in the other direction. Factors like major weather systems (El Nino type systems) and volcanic eruptions, can interrupt the long term trends in the short run. Your world wouldn't have to have an expanding desert. It could be getting steadily colder (e.g. ice ages), hotter, drier, more moist, windier, or anything else you could care to mention. Pandemics and Droughts and Floods Major disease outbreaks like small pox and the black plague tend to be devastating for several years, then die down for a few years, then come back with a vengeance, over time frames that can last decades or centuries before they entirely run their course. Pandemics, major floods (see China), catastrophic storm damages (see South Asia), and droughts often lead to civilizational collapses, that then usher in "barbarian" invasions of societies better suited to weak states and poor food production. When these disruptors ease up, however, society gets its act together a bit, drives off the barbarians or assimilates them and has a fragile new civilization until another disruptor screws it up again. There is debate over whether some of the periodic disruptors on Earth are caused by our solar system's period trips through unfavorable parts of its larger area of the galaxy environment and comet routes, etc. But whether that does or does not happen on the real Earth, it certainly could drive these kind of periodic disruptors at scales that would be tough for even technologically advanced civilizations to handle. Civilizational collapses of the Ancient Puebloans, the Mayans, the Incas, and the Mississippian peoples in the Americas are examples of that in the New World. Bronze Age collapse (ca. 1200 BCE), the fall of the Roman Empire (ca. 450 CE) and an earlier civilization collapsing arid period ca. 2000 BCE are examples of this kind of model. Economic development Monarchies and colonial empires rely on "rent based" economies like farming and mineral exploitation (e.g. oil and gas) or natural resource exploitation (e.g. lumber, "spice") to survive. Economies that are not "rent based" require the consent of the class of people who generate wealth (e.g. a diverse commercial and industrial sector) to function and tend to overthrow monarchies. If you start with a monarchy or colonial system and the economic viable of its source of rents becomes minor relative to other sources of economic wealth in the economy, revolution sooner or later, is inevitable. The revolutions and instability strike at the marginal point when neither the rents that supported the monarchy, nor the commercial and industrial economy that replaced that, is dominant, and when "current events" can upset the balance in one direction or the other. For example, the invention of the cotton gin, and of industries powered by water mills and coal and steam, meant that sooner or later, the American slave based plantation farming system of the American South in the 1800s was going to collapse eventually. But lots of factors influenced when and how this happened and could have led to an oscillation if something got in the way of that trend. Every country that has undergone economic development sees at least one and usually several regime changes near that margin of transition from undeveloped and resource based to an industrial economy. Side Issue On Timelines and Long Term Conflict Mortality > > A classic trope in media is the country that is constantly having a > revolution, with the logical extreme being a geographical region where > any map older than a year is woefully out of date as new nations rise, > borders shift, old nations fall and more coups are had than courses at > the following inaugural banquets > > > While maps change rapidly, there is a pretty much inevitable tradeoff between how long the conflict endures and how rapidly things change. If the situation is so dynamic that maps are changing in the region every year or two, the conflict is going to resolve itself in less than a decade or two. If you want a conflict that endures for half a century or a century, for example, while there is going to be significant change from time to time (and even that tends to happen in synchronized waves followed by periods of stagnation and stalemate) the conflict isn't going to progress quite that fast. > > However, I want to be able to explain how this region manages to stay > so politically active when every settlement in the area would have > lost their entire population of 20-40 year olds after about ten years. > > > While you can have a world like that, there is really no precedent for that level of devastation happening that quickly as a result of war. Most people who die in this eras aren't battle field casualties but casualties of the breakdown of civilization including war induced famine and disease that make the age breakdown of deaths more spread out. And, there are pretty much no historical military conflicts that killed more people than, for example, [the Great Northern War over twenty years (which was a proxy conflict) in Finland in the 18th century](https://en.wikipedia.org/wiki/History_of_Finland#18th_century) that reduced Finland's population by about 50% and was followed by several other major conflicts in the 18th century that reduced the population somewhat further (but again, not primarily from battle deaths of military aged men). Basically, people surrender no matter what the cost, or become refugees, before an entire generation of men is entirely eliminated, and conflicts that have that depth of impact take more than a decade. You generally only lose an entire generation of men in historical scenarios of conquest, akin to those described in the Biblical books of Judges and Numbers, or in parts of the New World in the Conquistador era, for example, where an invading Army kills all the men and all of the women unfailingly loyal to them, and then the invading Army takes the remaining existing women as wives replacing the existing men entirely but taking their place, rather than leaving a vacuum. Also, it is worth noting, that major wars like these generally lead to very high childbirth rates, approaching biological limits, although it is a less strong factor in leading to polygamy than you might naively expect (see, e.g., the case of very high rates of monogamy or non-remarriage among Southern Civil War widows even in communities losing a very large share of their marriage aged men). Caveat I've touched on lots of big picture interpretations at a very high level of historical events as examples. But, for these purposes, the accuracy of those interpretations doesn't matter. What matters is that those interpretations could explain what is going on in your world. [Answer] Badly designed democracy Look at the recent history of the United States. The person who loses the popular vote gets to be president because of the Electoral College system. Power swings back and forth between two increasingly polarized positions, with badly designed institutions like the Supreme Court becoming key battlegrounds. It's very hard to fix because by design changing the rules is difficult. Because each side is so far from the other policy keeps swinging from one extreme to the other (or in the United States' case from hard right to centre-right), with huge changes like affordable healthcare or limits on bodily autonomy happening every few years. Or look at the UK. It can't even keep to international treaties that it agreed to only months previously. Such democracies are also highly vulnerable to attack by other states and even individuals or small groups with relatively few resources, because one of the primary means of attack is now social media. Compared to democracies that promote coalition governments and cooperation these examples are highly unstable. It's not hard to imagine that with a bit more effort other countries could use propaganda and social engineering to keep them in a constant state of flux, which is essentially what Russia is doing today by sowing division. [Answer] ### A generous, loving religion allows you to free your parents/friends from hell. The prominent religion of the region states that: * The land was created by God as a gift to his people. * If their flag is flying from (these few sacred sites), their citizens will have eternal life. * The sacred sites aren't suitable for holding in a siege. They're easily accessed from all sides, difficult to fortify, and lack their own food / water supplies. * If someone dies while they're loyal to a group who doesn't hold those points, they're sent to hell. * When you capture all the places, all your recently deceased people in hell get released and get into heaven. * If you're in heaven and your side loses control of the sacred ground, you can stay in heaven. * Those whose death was violent, or who killed others (including in self defense) do not get into heaven and will be in hell eternally. This will result in armies armed with non lethal weapons, evicting near bloodlessly other armies from the sacred ground every few years. Once you have held the sacred ground, the motivation for holding it goes down (No one is suffering. You only wish to prevent future suffering). If you haven't held it for a while, your motivation to seize it goes up (people you know are suffering). A motivated attacker and an unmotivated defender will change hands quickly. Very few people will be willing to seize the castle by deadly force, as it excludes them from the reward of heaven. Most will attempt to fight non lethally, there'll be lots of capturing and exiling and imprisoning and then revolution and overthrowing. Some may fight lethally (they don't believe that part of the religion, or are just fanatical). You're better off running away from them, letting them take the grounds and then sneaking up on them later with non lethal. This should create an unstable map, different sides constantly gain motivation, gain ground, be unable to fortify it, lose motivation, and relinquish it. [Answer] # Very Simple Just put one or more groups of humans in the region. That's all you really need! Precious resources and odd geography are icing on the cake! You could have a broad steppe or a wide desert and any humans living there will, sooner or later, turn the place into a permanently unstable political region. So long as the technological landscape remains stable, the factions will harmoniously agree to disagree by thumping each other on the head with clubs. Once technology gets going, all hope is not lost! Sooner or later one group of humans will realise that they can throw big sticks at each other, thus ensuring greater survival for their own faction and greater loss to the other faction. But fear not! The other faction will catch on and start throwing sticks of their own...and maybe a couple rocks for good measure! Sad but true: Humans are strange in being broken in their minds and hearts and will almost always spontaneously form factions. And these factions will almost invariably be at loggerheads with one another. You don't need to anything but sit back make some metaphorical pop corn and enjoy the show! The real question is much more difficult: how is it that some regions have managed to escape the usual situation for any great length of time? [Answer] Polynesia was like this. All you need is belligerent chiefdoms vying for something that can never be satiated. For many this was 'mana' which is a spiritual power you're born with and can accrue through your achievements. Leaving the protection of your village or being banished could mean sudden death at any time. Then blood feuds, head hunting and all the rest go with it. Polynesians and others lived with this as the normal state of affairs for centuries. Any stranger was a potential danger and dependent on context were usually killed on sight, and everyone trained from children as warriors that may need to repel an attack at a moments notice. Leaders were always changing and trying to enhance their reputations, so politically it was constant flux. Most chiefly societies had something similar, the Europeans certainly did. [Answer] Revolution or Coup? There is some imprecision in the word "revolution," but one might make a difference between a violent overthrow of the current regime and a violent overthrow of the current social order. Only the latter is properly termed a revolution. * Imagine a country with several large, rural provinces and just one real city, the capital. Each clan is based in one or more of the provinces and they battle for control of the capital. Fresh fighters come down from the mountains or up from the coast, to meet in the customary battleground. The capital looks like a war zone, the rest is just poor and underdeveloped, yet taking the capital with the port facilities allows the clan which holds them to extract rents. * Similar for an area with mines, see blood diamonds. * Imagine a country which is de-facto ruled by organized crime. Every couple of years a new syndicate comes to power. The people might be caught in the crossfire, but the syndicates don't deliberately shoot people who do pay their protection money. The key to such a scenario is that the fighting factions don't see the population as citizens, they see them as a resource. There is an expectation that they'll tend their farms and pay their taxes, no matter who is in charge. Sure, there might be some scorched earth every now and then, omelets and eggs, but why kill the golden geese if you plan to reconquer them? And terror "makes an example" out of individuals only to terrify the rest of the village. [Answer] Most countries where either artificially introduced poverty or class jealousy have a tendency to constantly have fighting. Also lack of education can help this along, the closer people are to their animal selves, and nothing brings this out like starvation and misery, the more violent they tend to be. Unclean work conditions etc, however the people also have to believe they can win, so a surly or disgruntled soldier or police class is often a good place to start as well. If we're talking outside intervention, creating scandal most especially scandal that makes the man on top look like he's living like a literal king often helps, and lets not forget, almost EVERYONE has to be in the same state of living. Another major historical factor we have seen is having parallel living religious identities such as the difference between the sunni and shite muslims in the middle east, being many of them are raised to be COMPLETE zealots this is one way. The bosnian muslims and serbs were a more educated example. In general if a class of people is kept living well and seem to be either attainable by the poor class or that slightly privileged class is large enough to be larger than the poor class there is a high likelihood that the a revolution will never happen, most especially if they have been raised towards overtures of non vioelnce and civility in a state such as our own which either beats people down who turn this way or pacifies them through over civility. In such cases there it is highly unlikely a revolution will ever happen. There is also a question of personal identity, do people feel like they are property or like they are people who's lives matter. \\ if this seems familir, thats because this is familiar\\ [Answer] ## Looking at history, here's a few important factors. 1. Surrounded by oceans, mountains, or other impassible terrain on two (or if other factors are present, possibly 1) sides. This creates a bottleneck, forcing empires to go through your poor country. It's standard practice for empires to set up puppet-kings in conquered lands. Every time a new empire invades they'll end up with a new king. 2. Gold (of any variety). This creates a volatile climate, with various power-hungry demagogues constantly vying for control. 3. Blood-Feuds. Capulets and Montagues (these two actually existed outside of Shakespeare's play), Guelfs and Ghibellines, White and Black Guelfs, Amidei and Buondelmonti, the list goes on and on. Whenever you have two or more groups in a blood-feud you are guaranteed to have constant Revolving Door Revolutions, as each group takes power from the other(s). 4. Even better than Blood-Feuds, Religious Feuds. If the Middle East (and, for that matter, Reneissance Italy) is any indication, these are even more destabilizing than than Blood-Feuds. 5. Marx. Like it or not, Socialism is inheritantly unstable. Power-hungry Comissars and Dictators Benevolent, All-Knowing Philosopher Kings are given complete power over their subjects. Power corrupts. As a result, their political adversaries have a tendency to die in "accidents." While this doesn't comprise a full-on revolution, it does result in significant political instability. [Answer] It's all a big Conspiracy! There's a stable hidden power behind the ever-changing ostensive power. The hidden power is relatively secure by being unknown, any revolts stop at changing the ostensive power. The hidden power itself triggers a revolution against the ostensive power if it starts acting up, gets too unpopular, or too unpleasant to deal with for any reason. As done masterfully by The Order of the Stick (recommended). As commented by the TvTropes link in the question, under Webcomics: > > In The Order of the Stick, the Western Continent's empires rarely last a year, constantly getting overthrown by someone who sets up their own empire. Tarquin, after witnessing all this, decided to take advantage of it. He and his allies act as "advisors" to the rulers of the three largest territories, happily jumping ship whenever they get overthrown. Thus, the entire Continent is slowly being absorbed by three nations, but because their names are constantly changing, almost no one has noticed. > > > ]
[Question] [ What kind of pandemic could keep nations on severe lock down for at least long enough to necessitate irreversible changes to culture and the economy (preferably a decade or longer)? Such as fast-tracking automation, implementing UBI, and moving everything to a digital and robotic format (Like what's happening now, but without a clear off ramp). It can be of any severity, so long as it's not an apocalypse scenario (though it can be in some places). It should be at least a little scarier than Covid-19, but the main thing is that it should be nearly impossible to create a vaccine for and hard to treat in a significant way. A superbug, or something that mutates too frequently to build immunity to or combat. I want it to help shape a world where people can't leave their homes and interact through the world online, while automation does the majority of the labor in the nation. (The primary attribute I want is longevity, what could prove to be exceptionally challenging to rid the world of, while being just lethal enough to prevent leaving a lock down situation) [Answer] Step 1: Use a Retrovirus Retroviruses clone themselves from RNA instead of DNA. RNA is less stable than DNA; so, virus that use it for replication mutate MUCH faster than those that use DNA. This means that you will not have a single virus you can just vaccinate against, but an ever growing family of viruses such that you will already have new varieties of it by the time you come up with a vaccine for the ones that exist. This also negates herd immunity of those who have or have not had it since you could get it multiple times in your life as it mutates. Step 2: Make it contagious before symptoms progress This is actually the big detail that has make covid-19 worse than other more deadly ones like SARS. A disease that does not always present symptoms is much harder to selectively contain. Step 3a: Make it resistant to environmental factors A disease that can survive for long times in soil, on door handles, etc. will be more likely to keep coming back even after you think you've eliminated it. Making it transferable by other organism can have similar effect since the disease can appear to be wiped out only to come back later. You don't want to use a super spreader like mosquitos though since they can make quarantine virtually useless. You'd want to use an animal that is prolific, but has little direct interactions with humans so it can be reintroduced now and then, but not a major mode of transmission. Rodents could be good for this, since they are hard to wipe out, but easy to keep away from humans most of the time. Step 3b: Long dormancy period Some viruses can live in your body for 10 years without symptoms, then boom, they flare up and kill you. This can serve as a substitute for or work along side resisting environmental factors since again, it would make it impossible to simply eradicate and move on from. You do not want a 10 year dormancy of course because this would nullify the point of social isolation, but when you consider it took Covid-19 about 2-3 months to become widespread without spreading beyond controllability, something in this range might do. Step 4: Make it deadly, but not too deadly Covid-19 is again a good example of this. A disease that kills too many people will cause a general collapse in society rather than the social contraction you are looking for. Making the disease spread effectively but only typically killing people with preexisting conditions will encourage people to do things remotely as much as possible without making it impossible for logistics companies to continue to operate at all. If it kills normal healthy people then factories, food processing, and shipping facilities will close outright leading to widespread famine and civil disorder. Granted, full automation of industry and logistics would make mankind more resistant to a deadlier pandemic, but you don't want to burn the system to the ground before you transition to this. You need an infrastructure that can still mostly function despite the disease in order to begin manufacturing the needed automation systems to take human interaction out of the mix entirely. Since it rapidly mutates, you could have it start off only kinda deadly and then get progressively worse over time. Step 5: The existence of free societies There is a marked difference when you compare how totalitarian governments and free societies address an epidemic. Totalitarian governments have little trouble eradicating highly virulent diseases because they have it in thier power to really force lockdown protocols. They can close all thier businesses for a few month even if it means people go without "essential services", they can seal people into thier homes without food or medical support if they suspect an outbreak, they can execute and burn the ill instead of risking them getting more people sick while they recover... in short, they can do whatever they deem fit in the name of the "greater good" that free societies simply would not stand for. Instead, free societies give suggestions and guidelines that most people will abide by but some will ignore. These people who ignore the guidelines would make the total eradication of the illness impossible. [Answer] I can think of several, but here is my favorite. * Fever. * Headache. * Nausea. * Vomiting. * Agitation. * Anxiety. * Confusion. * Hyperactivity. * Fear of water. An airborne version of rabies would be especially horrifying. It would result in extremely (almost 100%) lethality once you had symptoms and it would have a fairly large number of reservoirs amongst animals. Infected people would behave erratically as the virus invaded their nervous system. Give it a longer incubation period and high mutation rate to make vaccines ineffective. I heard something like this suggested on a documentary as a possible zombie apocalypse substitution because of the behavioral changes. Nasty. * If this is too awful, there are huge stockpiles of engineered Anthrax in the former Soviet Union that as far as I know haven't been destroyed. Make a more aerosolized version and add multi-drug resistant plasmids. If it was a research facility that was raided, numerous antigenically different strains available in the inventory means a terrorist organization (for example) just has to release a new one every time someone develops a new vaccine or antibiotic.Inhalation anthrax is very lethal but slightly less encompassing.Inhalation (pulmonary) anthrax Inhalation anthrax develops when you breathe in anthrax spores. It's the most deadly way to contract the disease, and even with treatment, it is often fatal. Incubation period for inhalation anthrax can be weeks. This is from the Mayo clinic -<https://www.mayoclinic.org/diseases-conditions/anthrax/symptoms-causes/syc-20356203> Initial signs and symptoms of inhalation anthrax include: Flu-like symptoms, such as sore throat, mild fever, fatigue and muscle aches, which may last a few hours or days Mild chest discomfort Shortness of breath Nausea Coughing up blood Painful swallowing As the disease progresses, you may experience: High fever Trouble breathing Shock Meningitis — a potentially life-threatening inflammation of the brain and spinal cord [Answer] I don't think anything could. The thing is you can eliminate any human-only disease with a sufficient lockdown. Look at what China has done--at this point the threat is imports. It's easier to do that than remain locked down for many years. As some areas eliminate it the ones that don't will become more and more isolated and will in time also eliminate it. If it has an animal host a lockdown won't stop it. [Answer] Capitalism While not generally considered a pandemic, it creates the results you are looking for. Read "The Last Capitalist" by Liu Cixin (I think it's in "The Wandering Earth" collection). It describes exactly such a situation - everyone is confined to their small homes because the space outside is owned by someone else and they don't have permission to use it. In the story that situation is impossible to resolve, because under such confinement it is impossible to accumulate wealth to buy land. [Answer] I don't think there can be an infection that would be able to hold people indefinetely locked. Some kind of vaccine/cure would be found against it sooner or later. Instead I would rely on some kind of bad actor who would regularly bio-engineer and release viruses/bacterias/fungi that would cause pandemics if left unchecked. Such bad actor would need to have its secret agents all over the world (or alternatively, to be able to make its agents appear in targeted country despite all efforts of national security agencies of said country), so no country would feel safe and new infection would be able appear in many different places at the same time. And this bad actor should be able to manufacture new potentially pandemic viruses/bacteries/fungi so quickly that the poor humanity wouldn't be able to have a break. [Answer] None, at least not in a modern/current setting: For permanent indefinite lockdown to occur, we would need several things to happen: 1. The lockdown is effective - this means it has to be spread by human contact 2. Yet the virus isn't killed by the lockdown 3. The consequences and cost of dealing with the lockdown is better than the alternatives Points 1 and 2 are pretty tricky to combine. The virus needs to be permanently a risk factor, yet only spread via human to human contact. This probably means people don't recover or ever become immune or resistant and can remain contagious. It also means that the virus isn't always fatal, but is still nasty enough that lockdown is better than the alternative (including loss of life due to economic costs). Yet if this was the case, the cheaper long-term solution would eventually be to test everyone - then segregate society; perhaps via 'virus passports'. The virus would sometimes escape the segregation, and each such event would need to be dealt with. But each segregated group would be effectively free from lockdown. Getting to that point would involve an initial much longer-term lockdown than we are currently envisioning, but not decade long. I cannot currently see an easy/not-highly-contrived way in which a single virus/disease could be both untestable, like Dementia currently is, and also contagious. For a disease to be contagious something needs to be transmitted, which means there is something relatively obvious to look for. I also wondered if something like this might be possible if it wasn't just one virus, but rather repeated waves of different viruses. However closing international borders should be sufficient to prevent future waves spreading beyond their immediate locale. --- I could however envision something like this happening in a much more distant future, if people had sealed homes. That way the lockdown could be effective against viruses transmitted in other ways, such as by air or via animals, and we wouldn't be stuck with the consequences of human to human transmission. [Answer] You can engineer diseases already so just think of what you want to give people that incentives no or low contact. Families can't avoid one another in the same house neither can apartment neighbors there was a disease found in Africa that had no name but it slowly rotted its victims but they felt no pain until it came to inner organs some time later they were alive while their body parts fell off. The explorers who found the site met the village chief whose head promptly fell off and rolled to the floor mid speaking and the body moved for a time more before collapsing the end result the explorers took one look at the town and as soon as one got infected they said, "We can't let this be." They set up a rock message post then proceeded to kill off everyone via fire including themselves they stopped a pandemic situation. Their notes is what told anyone about what they had done and as far as they could tell no one survived to pass the disease on. People died of he common cold once. And there was that dancing plague briefly in the middle ages that was an odd ball you should look that one up. It seems things that rewrite the genetic code or function of cells is the hard things to combat with the body so its a matter of research if you really want to google stuff just look at incurable diseases and take notes on what commonalities they have then look at horrendous diseases and see if you want to graph that on you don't have to use real world diseases you could just have it come from a meteorite as it could come from an unfrozen necro plant from the dinosaur age as we have that occurring right now plants and flowers found in perma frost are springing back to life which is bad because we don't know if they'll also bring things we can't defend against. [Answer] I think the [bacillus anthracis](https://en.wikipedia.org/wiki/Anthrax), commonly known as anthrax, [might play the role](https://en.wikipedia.org/wiki/Gruinard_Island). Apparantly, the bacterium in question has the ability to stay dormant in the soil for many years and even decades, just lingering as a 'spore' in a metabolically inactive state. The ideology behind this disease's sustained lethality is quite different than the one of other answers here: the species evolves very slowly, if at all. But that property guarantees the continued lethality of the disease the OP is looking for (and the lethality of airborne anthrax is so great that a dynamics of humans acquiring immunity by having survivors have an advantage in the natural selection process must occur on a very slow time-scale) In a fictional universe, a large-scale conflict may have provoked a major power in detonating large anthrax bombs over enemy territory. The wind (jet stream) unexpectedly spreads the disease to other parts of the world which becomes widely contaminated. Anthrax becomes especially a more viable candidate for such a story if you suppose that the society after the conflict has lost major chunks of biological knowledge and fails to properly identify the culprit. To summarize, it seems that anthrax is useful in story/world building as an element to justify geographical no-go zones. To argue against anthrax, after consulting the [documentation of historical outbreaks](https://en.wikipedia.org/wiki/List_of_anthrax_outbreaks) it seems that anthrax has a poor spreading-dynamics after infecting subjects: human social behaviour does not as greatly enable this disease as it does other diseases. If the fictional society becomes aware of the anthrax-contamination of the soil, they will likely start to expand the uncontaminated safe-zones by ploughing away the top-soil of contaminated regions (and apparently using desinfectants like formaldehyde also works). [Answer] A more virulent ([lower recovery rate](https://en.wikipedia.org/wiki/Polio#Recovery)) form of poliomyelitis with physical contact in addition to [fecal-oral or oral-oral transmission](https://en.wikipedia.org/wiki/Polio#Transmission). The fecal route will sorta guarantee long term persistence in environment - how about having an entire species of ubiquitous birds (sparrow?) going extinct and littering large geo areals with infection spots? E.g. of occurrence - [enterovirus linked to flaccid paralysis](https://www.livescience.com/51451-paralysis-children-enterovirus-c105.html) (was not polio and wasn't studied before because the existing strains weren't debilitating beyond the infection period) E.g. of persistence in/transmission by soil: [Contaminated Soil and Transmission of Influenza Virus (H5N1)](https://wwwnc.cdc.gov/eid/article/18/9/12-0402_article) [Answer] # Prions Prions (like mad-cow disease) are not something your body can develop immunity to or that a vaccine can be developed for. They're almost impossible (maybe impossible) to sterilize because they don't have DNA or RNA - they are just a miss-folded protein. They have long incubation period so many people could potentially be infected and asymptomatic for a long time - even if you know you are infected you may have years left in your life. If prions ever became transmissible through means other than cannibalism, blood transfer, or surgical contamination it could be very bad news for humans. Imagine a whole segment of the population who have this easily transmissible prion, with a long incubation period, who now have to stay isolated until they die - or hang out with other infected people I guess. [Answer] Having recently watched the HBO Chernobyl miniseries, I keep drawing parallels between the current COVID-19 situation and a major worldwide radioactive disaster (like what could have happened at Chernobyl). Similarities: * Invisible, airborne particles that cause sickness and death * Transmittable by touch / close quarters / contaminated goods * Cleanliness can limit the spread * Requires seeking shelter and avoiding risky situations * Strains medical services and requires special PPE for staff Differences: * Viruses propagate from host-to-host, leading to the "curve" everyone's talking about as more people are exposed; radiation decays (slowly), so an area is exposed all at once and will not become more irradiated unless new radioactive contaminants are introduced * Viruses can be destroyed (e.g. soap) and nullified (e.g. vaccines); radiation is much harder to address once introduced * Determining whether a person is infected can be very difficult; detecting radiation is relatively straightforward * Any exposure to a virus could be life-threatening; "safe" radiation exposure can be measured and quantified * Radiation can take many thousands of years to dissipate All this is to say that you might find the circumstances you describe in a post-nuclear-disaster world (I know you said "not an apocalypse scenario", but we can imagine a survivable-but-dangerous level of worldwide outdoor radiation). You effectively shorten your lifespan every time you go outside, it's risky to interact with others in person or accept goods from the outside, and it will potentially take thousands of years for the outdoors to become generally habitable again. There might be cleanup efforts and work to shorten that timespan, and you don't have to strictly isolate, but for the foreseeable future it's not safe to be outside and would likely want to minimize interactions with others who may be more (or less) irradiated than you. ]
[Question] [ There are several questions related to effects of different gravity levels on the human body, but none adequately answer a fundamental question: What is the maximum and minimum gravity that nearly all humans can survive under and perform all functions without side effects? [This answer](https://worldbuilding.stackexchange.com/a/81840) says that many humans would receive significant harm in a 1.5G environment over a six month period and [this answer](https://worldbuilding.stackexchange.com/a/136277) claims that 1.5G would not harm healthy humans over a seven day period. [A third answer](https://space.stackexchange.com/a/6157) claims that Earth's gravity is the only gravity level that humans can tolerate over a long term period, yet I would imagine that 0.99G or 1.01G would not be much different than 1G; I can't find an answer citing the gravity levels that all humans can tolerate without any side effects over a long term period. To satisfy the requirements, the following terms must be met: * At least 95% of humans would not have any severe long-term effects that they would not experience on Earth caused by the different gravity level over a period of 5 years * All humans can survive in the different gravity level over a period of 5 years * Tasks essential for living in a society should not be interrupted by the different gravity * All other environmental factors are the same This does not require that machines operate correctly in the different gravity level, only humans. [Answer] We don't know. You are asking to know something which is similar to the [medial lethal dose](https://en.wikipedia.org/wiki/Median_lethal_dose) $LD\_{50}$. > > The value of $LD\_{50}$ for a substance is the dose required to kill half the members of a tested population after a specified test duration. > > > In this case you are asking for the $LD\_5$ at 5 years. Why we don't know? To make this kind of determination we would need to test various level of gravity on a lot of people to have a statistically significative sample, with different gravity levels, and have these people live in those conditions for 5 years. We don't have the facilities to perform such extensive studies, and those we have in place have been used to test subjects akin to astronauts, which are nowhere representative of the 95% of the population. If ever, they represent the 5% of the population. [Answer] We know that anyone with osteoporosis is prone to bone breakage even in a 1G field, but unless we're dealing with a very heavily aged population (due to reduced birth rate for population control?) that won't encompass anything like 5% of the population. We also know that beyond about 3G even normal folks in good condition will have similar problems -- back injuries just from walking around, for instance, and rapid knee degeneration. The effects of high gravity would be similar in many ways to morbid obesity; in fact, you could make a case that non-endocrine pathologies related to obesity can serve as models for a high G environment -- that is, living in 2.5 or 3 G won't make you diabetic (seemingly), but it's likely to cause most of the same other problems as if you weighed two and a half or three times what the health community believes you should. We also know that (nearly?) everyone will suffer bone and muscle loss in prolonged microgravity -- even with daily vigorous exercise. There are other effects from microgravity, as well, even less amenable to countering without artificial "gravity". Here, prolonged bed rest has been used experimentally as a stand-in for microgravity, because of observations that astronauts suffer some of the same issues as bed-bound medical patients. What level of reduced gravity is modeled by lying in bed is in question, but the studies I've seen via headlines seem to suggest that it's below 0.5 G, possibly as low as 0.2 G equivalent. Don't take this as gospel, however; I haven't specifically researched this and I don't work in any related field. Prolonged bed rest promotes loss of bone mass and muscle strength, as does prolonged microgravity, in virtually all test subjects. So, based on the limited data in hand, we can reasonably claim that any G field above 2 G is likely to cause problems over the long term for nearly all subjects, and fields below about 0.2 G as a lower limit are likely to cause problems for a significant fraction. [Answer] As [L.Dutch](https://worldbuilding.stackexchange.com/a/173239/37575) stated, we don't know a whole lot. We know that for top physical specimens, 0 g has serious effects, but nothing lethal so far. But we can hardly expect that to be entirely representative for the entire population. So what do we know? Well, gravity on earth isn't exactly the same everywhere. You may have been taught that g = 9.81 m/s2, 9.8 m/s2 or 9.79 m/s2. None of these are wrong, but except for 9.8 m/s2, they are overly specific. Gravity may differ by as much as [0.02 m/s2](https://earthscience.stackexchange.com/questions/7449/does-gravity-differ-from-place-to-place-on-earth) across the surface of the earth. So there's what we do know. $$LD\_5 \geq \pm0.02 m/s^2 $$ This remains true when changing 'Lethal' to 'Serious effects', though there are probably obese people who would do better in lower gravity. [Answer] The question is difficult (impossible) to answer both because no scientific data exists, and because of how it is worded. There exists some data which could be extrapolated, but it has a small sample size, was collected from a set of carefully chosen individuals, and the effect is intermixed with other effects (e.g. radiation, stress, air composition, nutrition). Thus, it is not possible to generalize to "nearly all humans", nor to blame any observed effect on gravity without the possibility of other factors also having an influence (unlikely as it may seem, but truth is we simply don't know, we can only assume what's likely). Reduced gravity most probably predominantly leads to bone demineralization and muscle atrophy (and possibly other things). That's because this is what people who are (among some other effects) exposed to reduced or zero gravity demonstrably develop. There may of course be other reasons for that effect, but gravity is the likely factor. Exercise can at least partially counter these effects, but exercise is not a premise of the question. If, what's very likely, gravity is indeed the deciding factor (and not e.g. NASA's bad nutriention scheme) simply because less "pull" means less stimulus, then the effects will likely occur at every significant reduction. Whether or not it counts as "not tolerable" is up to your decision, so it's fundamentally impossible to provide a number. Is it tolerable to have 5% less strenght and bone density? What about 10%? Who can tell. For a boxing champion or a rugby player it sure wouldn't be. For a computer geek? Why not. Seeing how "return to normal environment" is not a premise of the question (only "compared to" is), though, one might as well say "zero gravity is perfectly sustainable" since you do not need (shouldn't need?) strong muscles and hard bones in zero-G. Basically, it would mean: Yes, there will definitively be serious changes, but they aren't a problem. The same goes on the other end. Something like 4-6G will without doubt cause noticeable discomfort, and rather soon evolve into problems. However, 1G or 1.5G is not really much of a difference, nor is 2G. Only just, everything is a tidbit (tidbit, eh?!) heavier. You'll grow more muscle and denser bone, tripping and falling will hurt considerably more, and you'll need more energy. It'll be generally harder, your heart and your circulatory system needs to support higher pressure, but all in all, there's not really that much difference. Sure, more load on your spine, your knees, and on your inguinal canal. All in all, that's not precisely enhancing durability or longeviety. But there is no real reason why you couldn't live in 2G for 5 years, if you are reasonably healthy. Mind you, there's people who have 150-180 kilograms of body weight (or more?!), and some of these carry that around for 30-50 years. Do they eventually have problems? Well sure, but not after 5 years. However, "nearly all" includes infants and people who are 95 years old and suffer from heart insufficiency and COPD, so... it may be troublesome to make a claim! A baby in zero-G will be "fun" when gooey, stinky stuff comes shooting out of it at both ends. Which tends to happen regularly. A "typical" 95 year old will not be very happy in 2G, at least not for long. Someone with vein insufficiency will not be very happy either -- them thick legs getting twice as thick now. Allergic and going to zero-G? Well guess what, sneezing all day long can be a lot of fun! Speaking of infants, it is not certain in any way inhowfar growth in children (or animals in general) is influenced by low gravity. Generally, data about animals in space is relatively sparse, and in my opinion the conclusions that are made are dangerously naive. For example it is not appropriate to extrapolate from mouse experiments based on "they have short life spans, so this is a long-time mission for them" as has been done on the ISS. While it is true that their lives are shorter, it does not mean that they automatically experience long-term effects faster because of that. Sometimes, this "logic" holds, but sometimes it doesn't. Medical research is full with examples of this fallacy. Such as the famous longeviety experiments where a few years ago someone got "immortality, soon!" for humans because he managed to extend the lifespan of some bug from one day to two weeks or so. Which is great, but it's also entirely meaningless. Acceleration on Earth is constant within what's reasonable to claim. There's 5 Gal difference between the absolute lowest and highest, that's ~0.5%. The difference between what "nearly all" people will ever experience during their lives from mountains or denser ground is in the two-digit milli-Gal range. That is "constant" for all practical purposes. So, all we really know for sure is that most humans stay mostly functional most of the time at around 980 Gal (i.e. pretty much 1G +/- 0). And even under these conditions, 5 years are demonstrably not sustainable for some individuals. Tasks essential for living in a society should not be interrupted by the different gravity. Well, what does that mean! What tasks are essential for living in a society? As we are presently being forced to experience, going out and meeting people is not essential. Nor is working. Although both would in principle be perfectly possible in either a zero-G or a 2G environment. ]
[Question] [ In my world, there are giant fish, reptiles, and bugs. My question is, how would you be able to put a harness or saddle on a fish? Info: * Swamp bio being ridden by humans * Fish range in all different sizes but are mostly bigger than the average adult * Fish have different plant life growing off of them but can be trimmed if needed * Possibly a saddle and reins deal * All primitive materials like plants: vines, spider slick, leaves, wood; also basic metal skills. * There are no mammals so no fur or leather [Answer] Water is 1000x denser than air, and much more viscous. So saddling fish only works if you are going to be riding on the surface. That's on top of the fish having a shape that allows for saddling. [![Here's Arthur riding a horse](https://i.stack.imgur.com/sfjU7.jpg)](https://i.stack.imgur.com/sfjU7.jpg) If you are going to be underwater, you'd better be horizontal and grab the animal by some means. If they have shark skin, you might be able to hold on to them (you'll need a thick skin yourself, or gloves, or you may bleed). [![Riding a whale shark](https://i.stack.imgur.com/WzLfO.jpg)](https://i.stack.imgur.com/WzLfO.jpg) If you wish for something more natural than a saddle and hardier than plants, [remoras](https://en.wikipedia.org/wiki/Remora) will do: [![Remoras](https://i.stack.imgur.com/RNMVr.jpg)](https://i.stack.imgur.com/RNMVr.jpg) Or if the fish is male, you can hold on to them by the linus. Sharks and rays have two of these. This may also be used to cause the fish to release some nutritive, protein-rich secretion. [![This may be somewhat NSFW](https://i.stack.imgur.com/uGt1S.jpg)](https://i.stack.imgur.com/uGt1S.jpg) Aerial fish may be surfed on. There is plenty of literature on this: [![Freestyle aerial fish surfing](https://i.stack.imgur.com/ylNUi.jpg)](https://i.stack.imgur.com/ylNUi.jpg) [![Rein-style aerial fish surfing](https://i.stack.imgur.com/91uzH.gif)](https://i.stack.imgur.com/91uzH.gif) And here is a real life example, as seen in Sharknado 2: The Second One: [![Surfing on a flying shark](https://i.stack.imgur.com/MtHqA.jpg)](https://i.stack.imgur.com/MtHqA.jpg) --- In the comments, user3819867 called to my attention that just you might also like to ride inside a whale's innards. While whales are technically not fish, they are the best marine fauna for this mode of transportation. Real life whales have their throats too narrow to swallow an adult. A workaround would be having them swallow a human infant, which would them grow up inside the beast. But since we've already delved into DC physics here, you may wish to get inside marine fauna as an adult and ride it from there. I searched for images of people getting inside sharks and whales but everything I got was gory, so have an artistic rendition instead: [![That's Pinocchio's dad by the way](https://i.stack.imgur.com/sGklb.jpg)](https://i.stack.imgur.com/sGklb.jpg) Then again, that's not much controllable. You might want to do like they do it in Windforge, a game which is all about hunting whales for sport and turning their carcasses into flying contraptions: [![Oh the memories](https://i.stack.imgur.com/U8exf.jpg)](https://i.stack.imgur.com/U8exf.jpg) Don't buy that game though. The developers abandoned it halfway through development. Finally, if you really wish to invest in fish husbandry, you can start with [barreleyes](https://en.wikipedia.org/wiki/Barreleye), which have transparent heads: [![I actually think they're cute](https://i.stack.imgur.com/USQCl.jpg)](https://i.stack.imgur.com/USQCl.jpg) And turn them into [submarimons](https://digimon.fandom.com/wiki/Submarimon): [![The writers of Digimon had access to some really good pot, there is no other explanation](https://i.stack.imgur.com/HgtwB.jpg)](https://i.stack.imgur.com/HgtwB.jpg) [Answer] If humans ride it strictly on the surface, a saddle-like seat made out of vines is a good anti-slip material for the rider. The contraption is a belt which wraps around the body like a belt, with loops into which the dorsal fin and side fins can fit. This will hold the seat in place and prevent it from sagging and turning. (Yes, fish skin is very slippery). Reins for controlling direction work well too. If the fish is ridden underwater too, you have a serious issue with water resistance. The saddle would be modified to allow the rider to lie down on the fish's back. He/she may need to strap his/her waist to the saddle and the feet holding on to the stirrups, which are strapped to the saddle. The rider needs to release him/herself quickly for air, in case the fish does not rise to the surface for a reason. Saddle parts <https://en.m.wikipedia.org/wiki/Saddle#/media/File%3AEnglishSaddleParts.png> Can be modified to suit the task. [Answer] The experiment has been tried successfully at least once and is in the literature. Chap called Jonah traveled for a while inside a fish. The details are vague but we must assume that he dined on the fishes innards since he didn't take provisions and got his oxygen from air pockets or gas filled bladders. [Answer] I would like to suggest the low-tech solution of utilising the skin plant-growths on the animal itself to weave a sort of harness or net/basket, while preserving the physical attachment to the animal. This method uses minimal material and also enables a variety of option of riding in a saddle, a mounted platform or while being towed. I think it also allows for a little more fish shape/species diversity as a system e.g. horse, elephant and chariot styled fish vehicles. ]
[Question] [ I've been thinking about developing a loosely cyberpunk style world that is mostly the sort of standard corporate dominated dystopias we're used to. How could a more positive mostly heroic faction emerge within this sort of world? What would be the factors that allowed them to form? [Answer] Anything natural is a cause for optimism because it is a gritty genre Any small bubble that manages to cultivate green things:that has a green house, a living plant, a living animal or even just natural light poking through, that is a sign for hopefulness in a Cyber punk world. Bear in mind that usually in the cyber punk genre, a green space tends to be an artificially generated mirage. Even Beautiful natural things tend to have some underlying fragility, or worse... totally sinister artificial corruption. Find a beautiful girl? Go visit a life long friend in the country? Look at a beautiful iridescent butterfly in a clearing in the forest? Not likely. The girl might be a robot trying to kill you. The long lost friend already has traded you over to the predictive crime police. The iridescent butterfly is a drone spy with camera eyes. Generally speaking the hero is talking through a slot, under neon lighting, after overdosing, intending to buy a black market body mod. Living in over populated, dense metropolises occupied by seedy modded biohackers with no scruples is not a cause for optimism. The denizens of these worlds tend to be losers, perverts, hackers, hucksters, hustlers, cutthroats, hookers, gangsters, reluctant cops, assassins, scavengers and rogues. A debatable hope for humanity is usually an AI, which sits in a grey area. They may be evolving as finer versions of humans, closer to a race of gods and goddesses, with more attuned intelligence and emotions than we can dream of. The fact is, in Cyber punk, nobody can leave the density of their world, raise children, lie down in a grassy field, or look at the stars contemplatively. A minor break from what is canonical would be a easy to achieve in this setting. It is like a scale from artificial (consistent with the genre) to natural (sticks out like a sore thumb). An extreme break from the general cyber punk genre would be to build an unselfish faction that wants to encourage themselves and others to return to an uncluttered, contemplative way of life. They could be community builders, honest crafts people, farmers, or conservationists. [Answer] Open source hackers These people make open source drugs, prosthetics, and bootleg products of all sorts. Real word examples of this exist, for things like insulin and 3D printed prosthetics, but this could expand when corporate control starts to infringe on these enterprises. These people would be decentralized without a central command. They instead set up independent pirate stations that distribute the hacked items and collect contributions. A few people work with them full time, some work part time, and most people only interact with them occasionally for free movies or one off services. They are anti-corporate, individualistic, and not prone to violence due to the low level of involvement most people have. They can get things done when things get bad enough that most people know about a problem. But mostly they don’t mess around too much. The people who do work full time can be heroes, with a diverse background, but for the most the group doesn’t get up to much that effects other factions. [Answer] The oppressed The cyberpunk story hero is the poor, angry youth, who has powerful enemies. It is a dystopic world, left to them by the old ones. They have to survive and regain their freedom. The enemies are the Central AI, agents of the state.. thought police.. employers.. and of course parents. Really very sad, little room for optimism, plenty room for anger. The privileged The cynical part of the population would contain the lucky few, the ones that enjoy real freedom and keep their oligarch tyranny in place, by faking the parliament and repressing the population. The members of that faction will enjoy all positive prospects that come with the honor of membership. The faction will be populated by the rich, the rich kids, the military, the police. There is little optimism in these circles, it's mainly fear and greed, which drives them. The pink glasses Your faction members, being proud of their optimism (they call it "positiveness") are mainly politicians and managers, the so-called representative and accountable people. They don't have any incentive to admit errors done in previous terms. The current dystopic world is not their fault, "someone 100 years ago messed up",they have a blind spot for the corrupt top. Although they don't really solve problems and don't protect the population, they insist they do.. and they regard their work of major importance, because it will provide a better future for everyone. Some day.. [Answer] There's a reason why cyberpunk concentrates in cities. Wide open spaces are hard to control. Your optimist faction has a lot of countryside enclaves. The cost of hunting them down is enormous, and they have learned to leverage their position into advantages. Highly concentrated attacks aren't much good against the dispersed. [Answer] Online trolls and hackers. Consider a smallish movement that has learned to adapt to ways of the new world and, more importantly, learned to have a lot of fun trolling and hacking it, causing embarrassment and chaos. When companies, politicians, media, or other organizations get too big for their britches, the trolls have a blast taking them down a knot. This could be for a deeper social responsibility reasons, or maybe they just like having fun and they're not going to let the corporations ruin their vibe. [Answer] ## Mormons (or some other religious sect) In real life there are groups of people who are optimistic, friendly, welcoming to strangers, good neighbors, etc - even when they themselves are not particularly prosperous (though people with strong social networks do often prosper). Very commonly, these are religious people (because group cohesion and friendliness often come from a view of being part of something larger and more lasting than their individual lives). A politely but firmly evangelical sect will be most motivated to be friendly; they're out to convert you, so of course they'll be nice. In a cyberpunk story, it doesn't have to be a real-world religion. And just like real life, not all members of a given denomination will be equally stellar individuals. But if most of the "members" really are friendly and sincere (though not necessarily without biases and faults)... Well, such a group is likely to be a unique inclusion in the cyberpunk genre, in any case. Also, if it's an underground(ish) movement, you don't have to be terribly specific about whether there are only a few of them, or whether they actually have significant numbers and/or power. [Answer] # Friendship and Positive Thinking! ## (with a helping of wealth and genetics) Dystopian fiction can fall into the trap of portraying everyone as pessimistic, malcontent, and selfish. This is unrealistic, though, as many in real life manage to be optimistic, happy, and altruistic in even the most dire of situations. It would not be surprising at all that a faction of "heroes" would form to address the many problems in your Cyberpunk world. In his book, "[The Happiness Hypothesis](https://rads.stackoverflow.com/amzn/click/com/B003E749TE)," Jonathan Haidt identifies three factors that contribute to happiness: 1. Healthy Life Circumstances -- Adequate wealth, social support, etc. 2. Healthy Attitude -- An appreciation for what one has instead of obsession on what one lacks 3. Healthy Mental State -- The ability to focus on positive things instead of ruminating on the negative things Your heroes could come from all walks of life. Your plucky and unfailingly chipper street urchin might team up with a wealthy but disillusioned elite and a religious ascetic whose risen above it all. Conservationists might offer green spaces as a respite from the world with the logistical support of ethical hackers and the financial backing of professionals with modest means. Of course, this all assumes your dystopia isn't too dystopian... * People's emotions aren't manipulated or their information too tightly controlled to prevent independent thought * People are able to establish healthy relationships; they aren't completely isolated or alienated * It's possible for people outside the establishment to earn an income and accumulate some wealth * People aren't all severely deprived or manipulated in some other fashion In short, if there are people with enough autonomy and resources in your fictional world, then it'd be completely realistic for there to be some optimistic go-getters working to make a better world. [Answer] Well, that kind of depends on your definition of "hero" doesn't it. There are a few such entities in SF, mostly from the golden age works, which operate on the principle of Enlightened Self Interest. This principle is stated in varied ways, but the phrase "a rising tide lifts all boats" is a reasonably good starting point. Rather than attempting to dominate the economic or political power of the world these organisations work, sometimes secretly, to ensure that advances that would benefit all are made available to as many people as possible. A few such can be found in the CP genre, if you look hard enough. They're not utterly selfless of course, in fact they're more selfish than the average. They just believe in the principle that more power/money/whatever can be gained if more is available in total. That the more money people have, the more they can sell to them. Of course their public image may not be particularly heroic, but at least they'll generally appear less bad than many of the others. Then again there are those organisations that very carefully curate their public image to ensure that they are perceived to be The Good Guys, but hiding in the depths of their shell companies, contractors and other corporate skulduggery there are all sorts of rotten, despicable hidden things. Books and covers, I guess. And then there are the Idealists. Without some serious backing these guys usually end up being eviscerated - hopefully in a corporate rather than corporal sense - by their less scrupulous competitors. Idealists try really, really hard to be above board, honest and honorable in all of their dealings, but they soon find that the game is rigged against them. Without a core of steel they're marshmallows in a fire... tasty if carefully done, but doomed nonetheless. Other than that, you're essentially looking for a group that operates outside of a broken system. Hiro Protagonist. The Lo-Teks. Even Johnny Silverhand, although more so in his original back-story than the (quite entertaining) Keanu Reeves version from CP2077. There are plenty of edgerunners (hackers, street samurai and even a few fixers) who are out to fix the world, one corp-hack at a time. Of course you have the occasional kind-of-good-guy powerful figure whose massive wealth and power have allowed them to make the choice to do good in the world. William Shatner's character Walter Bascom from TekWar springs to mind. It could be argued that Uncle Enzo qualifies here too... although it's kind of difficult to view Cosa Nostra Pizza as a heroic organization. [Answer] I got your steampunk hero right here! > > Non-violence leads to the highest ethics, which is the goal of all > evolution. Until we stop harming all other living beings, we are still > savages - Thomas Edison. > <https://www.brainyquote.com/quotes/thomas_a_edison_104088> > > > [![young edison](https://i.stack.imgur.com/xQfi6.jpg)](https://i.stack.imgur.com/xQfi6.jpg) [source](https://en.wikipedia.org/wiki/Wikipedia:Featured_picture_candidates/Young_Edison) You want a steampunk hero? Thomas Edison will do. He was a full on genius and invented lots of things that people used, and got rich, and then invented more things. He wanted to invent things people would buy, because that meant those things were useful and good. He refused to use his genius to work on weapons and was an outspoken pacifist. He advocated for women's rights and financial reform to help poor people. Plus he was a pretty sharp looking guy. [Answer] If the world around them is over-saturated with technology, corruption and oppression, then maybe a way of elevating oneself above that would be to live apart from those restrictions and place more of a focus on spirituality. Something like Buddhism which, while not rejecting the material world, seeks to not be overly tied to nor held down by it. Or some other kind of religion that puts spirituality ahead of materialism. They could even go full-on rejection of modern technology and live Amish-style. Maybe they could also be a charitable organisation that seeks to alleviate poverty in this world. [Answer] really, just any hardened leftist revolutionary group hope son't die because consequences are dire. if anything, it would be those dire consequence that are more likely to cause a faction about to do uprising. i can insure you that people who take risk for their future are if not optimistic about their future, at least hopefull that if they fight for it, it might be better. Super rich who want to feel good for a more different aproach... make it the sons and daughter of the uber rich. they are convinced that the system work mostly work, they are happy with it, but want it to go further and of course they would have a positive outlook on thing: they are already strating from the winning position. [Answer] You might take a look at a group Bruce Sterling invented for Heavy Weather. IIRC, they were called the "Regulators", a nomadic bunch that crossed back and forth between Texas and Louisiana in green-fueled RVs. They had managed to develop a "parallel economy" so that, though they weren't rich, they weren't dependent on the favor of the traditionally wealthy. ]
[Question] [ The "Lagrange giant" in the title refers to a gas giant that orbits its star in the same distance as Earth does. The alternative description is "Trojan planet" or, to be most clear, "co-orbital". So in this alternate universe, the only difference in our solar system is that a gas giant (let's start with Jovian in size and Class I in Sudarsky's classification, as those are the most familiar factors) orbits the sun at a distance of 93 million miles, meaning that it must share its orbit with Earth. How to do this without turning Earth into a moon? Physicist Sean Raymond proposed that such planets sharing that same orbital plane must be separated by an angular distance of 60 degrees. At such a distance, can anyone standing on the planet Earth even see this Trojan co-orbital giant? If yes, how would it look in the sky? [Answer] # VERY visible The giant planet would be at the [L4 or L5 Lagrange "trojan"](https://en.wikipedia.org/wiki/Lagrange_point#Point_stability) point of Earth around the sun. Or, more accurately, Earth would be in the giant planet's L4 or L5 Trojan point. Stability: For a L4 or L5 Trojan point to be stable, the mass ratio of the primary(the sun) to the Giant needs to be at least 25:1, and the mass ratio of the Giant planet to its Trojan companion needs to also be at least 25:1 Math here: <https://wmap.gsfc.nasa.gov/media/ContentMedia/lagrange.pdf> For a Jupiter size giant planet, with Earth in the trojan point, these mass ratios are well satisfied. The orbit will be stable, even in astronomical timescales. The Earth's moon would also be allowed in a similar configuration as present, although that orbit will be only somewhat stable, and will lead to loss of the Moon much sooner than for the current configuration. Appearance: The giant will be visible at 60 degrees from the sun. Either leading before dawn (if Earth is at L5) or trailing after sunset (if Earth is at the L4 position). Jupiter will display as a ~~perfect half-circle~~ gibbous orb, pointing towards the sun. It will have an apparent diameter of 0.053476 degrees, almost exactly 1/10th as wide as the Moon. Assuming that being nearer the Sun does not change its appearance, it will have an apparent brightness of 0.73% of the full Moon, or some 75 times brighter than Venus at its best. It will definitely be visible even in full daylight, as a small pastel semi-circle. [Answer] These are the [Lagrangian points](https://en.wikipedia.org/wiki/Lagrange_point) of the Earth-Sun system. [![enter image description here](https://i.stack.imgur.com/3I903.png)](https://i.stack.imgur.com/3I903.png) > > L1, L2, and L3 are on the line through the centers of the two large bodies, while L4 and L5 each act as the third vertex of an equilateral triangle formed with the centers of the two large bodies. > > > The L4 and L5 points are stable gravity wells and have a tendency to pull objects into them. The points L1, L2, and L3 are positions of unstable equilibrium. Any object orbiting at L1, L2, or L3 will tend to fall out of orbit. > > > The L4 and L5 points are stable provided that the mass of the primary body (e.g. the Earth) is at least 25 times the mass of the secondary body (e.g. the Moon) > > > L4 and L5, for an observer on the terminator, will be 60 degrees above the horizon, and will therefore be visible for about 4 hours after sunset or 4 hours before sunrise. Being the body a giant, it will surely reflect enough light to be visible. [Answer] I think the title of trojan planet would go to the smaller body in this case. The L4 and L5 points sit at the apices of conveniently equilateral triangles, assuming the orbit in question is basically circular. That means that if Earth were a trojan, the body it co-orbits with would be ~1AU away from us (or about 150 million kilometres). If the body were Jupiter sized (ie. ~143000km diameter) its apparent [angular diameter](https://en.wikipedia.org/wiki/Angular_diameter) would be about 3'17" of arc... that's about a tenth of the diameter of the moon or sun as seen from Earth, and much larger than any of the other planets. Given that the average human eye (whatever that is) can a resolution of approximately [one arc-minute](https://en.wikipedia.org/wiki/Naked_eye#Basic_properties), the planet being three times larger than that should be obviously a small round blob in the sky, not just a bright point of light. (I did originally say "circle" here, but it'll be only a partial circle on account of being at an angle to the sun... it may or may not appear to be a circle to the naked eye, but even with low-powered binoculars or other assistance it'll be obviously non-circular. It'll always have the same size and shape, regardless of time of day or year) For a rough scale example, here's a picture of the moon with an approximately 3 arc-minute diameter circle drawn on the Mare Serenetatis, which is about 6 arc-minutes across and you can pop outside the next time you have a clear night with a full moon and see the relative size for yourself. [![3 arc-minute circle drawn on the mare serenetatis](https://i.stack.imgur.com/jmKfs.png)](https://i.stack.imgur.com/jmKfs.png) Jupiter's [absolute magnitude](https://en.wikipedia.org/wiki/Absolute_magnitude#Planets_as_diffuse_spheres) $H$ can be calculated from its diameter and its geometric albedo (0.538), giving approximately -9.5. The apparent magnitude of the same planet in Earth's orbit but 60 degrees away would be: $$m = H + 5\log\_{10}\left({D\_{BS}D\_{BO} \over D\_0^2}\right) - 2.5\log\_{10}\left(q(\alpha)\right)$$ where $H$ is the absolute magnitude, $D\_{BS}$ is the distance from the body to the sun, $D\_{BO}$ is the distance from the body to the observer, $D\_0$ is the distance between Earth and the Sun and $q(\alpha)$ is something called the phase integral which for a diffuse reflecting sphere (which is a reasonable model for a planet) at 60° is about .406, and represents the portion of sunlight scattered from the planet that is bounced towards us. All of the distances are conveniently 1AU, giving the gas giant an apparent magnitude of -8.5. That's bright, by the way... brighter than [any other star or planet in the sky](https://en.wikipedia.org/wiki/Magnitude_(astronomy)#Examples) and exceeded only by the Moon and the Sun. It would be 25x brighter than Venus at its brightest (and Venus can be seen by the naked eyes at dawn and dusk), 10x brighter than the ISS, and equivalent to the brightest [iridium flares](https://en.wikipedia.org/wiki/Satellite_flare#Iridium_flares). You can't reliably see things that are as bright as those flares these days now that the original iridium satellites have been deorbited, but they were apparently possible to see during daylight hours, even outside of the normal Venus-viewing timescale. [Answer] Yes, a Jupiter sized planet in the same orbit as Earth would definitley be visible. The planet Jupiter is visible to the unaided eye in the night Sky even when about 400 million to 600 million mils from Earth, so if it is moved to about 93 million miles from Earth it will be much brighter and more visiple. If the solar system has a much dimmer star, the analogs of Earth and Jupiter would have to share an orbit which is much closer to the star than in our solar system for the analog of Earth to be warm enough. Because the Moon's orbit is elliptical and it gets closer to and farther from Earth, the angular diameter of the Moon as seen from Earth varies between 29.3 and 34.1 arcminutes. Since there are 60 arcminutes in a degree of arc, the angular diameter of the Moon as seen from Earth is about half a degree. Jupiter has a equatorial radius of 71,492 kilometers, and thus an equtorial diameter of 142,984 kilometers. To have an angular diameter of 0.5 degrees, Jupiter would have to be at such a distance that the circumference of the circle around the observation point would be 720 times 142,984 kilometers, or 102,948,480 kilometers. So the radius of that circle would be 16,384,773.32 kilometers. So the Jupiter analog and the Earth analog would orbit the Sun analog at a distance of 16,384,773.32 kilometers, and they would be spaced 16,384,773.32 kilometers apart along the orbit. 16,384,773.32 kilometers is about 0.109524447 Astronomical Units (AU), or almost 11 percent of the distance between Earth and the Sun. I note that the potentially habitable exoplanet Gliese 180 b orbits the red dwarf star Gliese 180 in its circumstellar habitable zone at a distance of 0.103 AU with a period of about 17.38 days. Gliese 180 is a specral type M2V or M3V star. And a planet orbiting its star that closely would become tidally locked to that star, having its rotation slowed until one side always faced the star and the other side always faced away. That might make life impossible on the planet. On the other hand a sufficiently dense atmosphere and oceans might transport heat from the day side to the night side of the planet. And the gravity of the nearby Jupiter analog planet might prevent the Earth Analog planet from becoming tidally locked to its star. [Answer] Suppose Planet X is located at the Earth-Sun L3 point - would it be hidden from us all the time? No. Since Earth's orbit is elliptical, Planet X would be visible shortly after Earth passes its perigee. This problem is found in Goldstein's Classical Mechanics. ]
[Question] [ The capital of a country is built on a series of stone hills that gradually lead to the ocean. The stone is noted for both the strength of castles made from it and its unique blue-green coloring. This city is surrounded by the ocean on one side, and steep mountains (which are responsible for the area's long rainy season) on the other. What would be the best stone to use for these hills? The first stone type is sedimentary. I think this one is unlikely, as sedimentary rocks don't usually exist in a blue-green color, aren't the best at withstanding erosion from constant rainfall, and generally aren't very good for building castles. [Coquina](https://en.m.wikipedia.org/wiki/Coquina), on the other hand, is one example of a sedimentary rock which would be good for building fortifications. Next are igneous rocks. The color could come from underground mineral deposits, and the hills themselves could have been made from gradual lava flows. Igneus rocks can be very strong, withstanding both erosion and attack. Granite is a great example. Metamorphic rocks are last. They can come in many different colors, with blue and green already being fairly common. While generally not as hard as igneus rocks, they could start as igneus rocks and morph over time, eventually being uplifted to the surface. So, in summary, my question is this: What rock can I use that is strong, contains a mineral that makes it blue-green in color, and can form in a series of hills? [Answer] ## Can I recommend some [serpentinite](https://en.m.wikipedia.org/wiki/Serpentinite)? Literally named for its greenish color and certainly bluish under certain lighting, serpentinite is your best bet for a couple reasons. First, it’s highly durable. [Serpentine group](https://en.m.wikipedia.org/wiki/Serpentine_subgroup) rocks are metamorphic, forged at depths of up to 60km inside the earth and exposed by uplift and erosion. This process often leaves the serpentinite exposed on the surface, and its durability means that it persists even when the other nearby rocks have worn away, making them [popular amongst rock climbers](http://bayareaclimbing.blogspot.com/2011/09/split-rock-turtle-rock-ring-mtn-tiburon.html?m=1). ![Turtle Rock, a serpentinite formation in Marin county](https://i.stack.imgur.com/5YLdv.jpg) The tendency to produce individual, boulder-sized rocks gives another excellent reason to make castles out of it - you just have to pick them up and pile them in the right way. Their abundance and diversity means that mining and excavation is minimized without compromising on quality or sturdiness. You’ll still want a few carvers on hand, but the hard work has largely been done for you. Here’s an example of a serpentinite building: it’s held up for a few hundred years so your castle will have an acceptable lifespan as well. ![Serpentinite building in Philadelphia](https://i.stack.imgur.com/dTgRW.jpg) Additionally, serpentine minerals are already found in rolling hills and near oceans. They’re also famous for specialized and exotic plants that have grown accustomed to the high levels of cobalt and cadmium in the hills. This makes for some cool botany already even if it isn’t a part of your story. If true serpentinite isn’t blue enough, well, it’s metamorphic! [Mix some blueschist](https://link.springer.com/article/10.1007/BF00376885) in there and you’ll get a darker, bluer stone. Blueschist is a bit more fragile than serpentinite because it has a few planes of good cleavage, but after some significant serpentinisation it’ll probably be nearly as hard. Fortunately, blueschist forms under similar conditions and locations as serpentinite. ![blueschist](https://i.stack.imgur.com/hhs1f.jpg) [Answer] Granite comes in a variety of colours, green among them. Unless your kingdom is sitting on a veritable bonanza of emerald and turquoise, I'd lean towards granite. [![Green granite](https://i.stack.imgur.com/c0Koc.jpg)](https://i.stack.imgur.com/c0Koc.jpg) From what I've read, granite doesn't come in blue. Other types of stone are marketed as "blue granite". I think you could argue the stone above kind of looks glasy-greenish-bluish. Granite has been long used in fortifications, of which the castle is a type: [![Peter and Paul Fortress in St. Petersburg](https://i.stack.imgur.com/xGnNV.jpg)](https://i.stack.imgur.com/xGnNV.jpg) Granite also has the benefits of being durable and of not being a source of asbestos, which is of concern in, for example, serpentine. [Answer] Have them build a log castle out of petrified wood. [![petrified log](https://i.stack.imgur.com/v2FN0.jpg)](https://i.stack.imgur.com/v2FN0.jpg) <http://museum2.utep.edu/archive/fossils/DDpetrifiedwood.htm> You can have a forest's worth of these. Giant, ancient trunks larger than any trees that exist on earth today. Any color you want, and many colors if you want that - whatever minerals produce the crystallization will confer their colors to the logs. The logs are stone and will last forever. They can be used as is, for a sweet log cabin look. [Answer] Blue quartzite, perhaps? It is a hard metamorphic rock. The colour is fairly subtle rather than bright blue in most of the pictures I can find on the internet. [![Pale blue quartzite](https://i.stack.imgur.com/iRPfI.jpg)](https://i.stack.imgur.com/iRPfI.jpg) I can't say for sure if the really strikingly blue polished examples are as the stone appears in nature, or if it have been enhanced by dye for the interior decor trade. [![Polished blue quartzite](https://i.stack.imgur.com/AxUyu.jpg)](https://i.stack.imgur.com/AxUyu.jpg) [![Another polished blue quartzite](https://i.stack.imgur.com/ROMxl.jpg)](https://i.stack.imgur.com/ROMxl.jpg) [Answer] May I recommend [Jasper](https://en.wikipedia.org/wiki/Jasper), jasper is usually agatised clay of some description, (clay that has been cemented together by silica deposited by geothermal fluid) it varies in colour from red to bright blue depending on the exact mineralogy. It is very hard wearing in nature and fully capable of forming mountains in quantity. Jasper is mechanically comparable to the iron cemented sandstone they're using to build [Guédelon Castle](https://en.wikipedia.org/wiki/Gu%C3%A9delon_Castle) being very hard but relatively easy to work. [Answer] Tourmaline. (enclosed in some mother rock) [![enter image description here](https://i.stack.imgur.com/rWWg6.jpg)](https://i.stack.imgur.com/rWWg6.jpg) Tourmaline is extraordinary hard : on mohs scale it has a rating of 7–7.5. (between quarz and topaz) (10 would be diamond already) Tourmaline is much harder than marble (3-4) (and most likely also harder than serpentinite and petrified wood as well) it can have many colours but it can be blue-green colored as well. ]
[Question] [ THE SCENARIO: I've been inspired by shows like The Shield and The Wrong Mans to come up with my own (even more flamboyantly evil) development scheme, to use as the backdrop for the action in a low sci-fi crime story set in modern day Detroit. Here's the direction I've taken: My smirking corporate villain contracts with the city to build a state-of-the-art job-creating factory in a slum, using land bought under eminent domain. The city government offers to reimburse him for X-million dollars, provided his own investment first exceeds a stipulated, much larger amount. The villain then proceeds to build a really incredible factory ... on paper. He invents an array of dummy contractors and fake expenses to inflate the size of his own investment. Meanwhile, the factory that he actually builds is a rickety shell of a building made with the cheapest materials possible. He pays for most of it with the public money, and funnels what's left to a private overseas bank account. Finally, to cover his tracks, he firebombs the property, causing it to collapse. He plants evidence to direct the blame on local gangs, and then quietly backs out of the project citing the level of risk posed to his workforce. He may even be brazen enough to claim the insurance at the inflated value, though I suspect that's the stage that invites the most serious risk. THE QUESTION: Neither white-collar crime nor urban renewal work is exactly my specialty, so this entire idea may well have some serious holes. If so, my goal is to discover them, and hopefully patch them. So, could this scheme be easily detected, and if so is there a way to get around that? --- BOUNTY EDIT: I've started a bounty only to reward some of the answers I already got. More answers are always welcome, but the bounty is already set aside. It just says I can't award it for 24 hours, so, until then... [Answer] The hole in your story: You seem to think people working for government are either 100% stupid or 100% too lazy to do their job; that will not be the case. You have inspectors, for one. Building inspectors, safety inspectors, accountants, bookkeepers and other bean counters. There are many, many safeguards in place, both legal and routine, in every major public budget. There are only two types of multi-million dollar contracts: Corrupt ones, and legitimate ones. You sound like you are aiming for a legitimate one, something politicians want to point to as an accomplishment: Publicized contracts like that extend to hundreds of pages when millions are involved and will be monitored. You will have a schedule to keep, milestones to reach, and the people doing the inspection will not be glad-handing politicians but actual engineers, architects, electricians, plumbers, drainage experts, safety experts, fire marshals, etc. You will not get a choice in the Insurance inspection, either. The fire marshal and arson investigators do their job no matter how innocent the fire may look; they are trained skeptics and will involve the insurance company and look into your financing to seek motives for setting the fire. And find it. If you want a plausible story, do not depend on your opposition being a caricature of stupidity and laziness that is so easily fooled. If cities really were as incompetent as you portray them to be, they wouldn't exist. You need a reason for professionals, with the authority to look into every nook and cranny of your developing jobs center every month, and a natural interest and pride in serving their city and preventing it from getting ripped off, to not hit the brakes: They need to believe you are putting your money where your mouth is; and some ramshackle warehouse decorated with some motivational posters is only going to convince them to look deeper. # Added If you want to save your story, ditch the city, and ditch the smirk. Make your criminal "The Music Man" (watch that old musical with Robert Preston); a con man of consummate skill that convinces non-government companies, charities, wealthy donors and more that what Detroit needs is a Jobs Center! (Robert Preston convinces the citizens of River City they need a Boys Band). Preston actually delivers the musical instruments; your guy actually delivers the Jobs Center, it just isn't going to work they way he said it would. The Music Man had a surprise happy ending with an innocent love story; but your story can end however you want. Inspectors will let you build something that just barely meets standards, it is not their job to ensure you keep your public promises, just that you meet the minimum allowable standards. They don't care if you collect \$100M in donations and are still begging for more on TV, even though they know you have only spent \$5M of it, and your "artistic renderings" of the Jobs Center cannot be realized with what you are doing -- the space isn't big enough, you are putting cheap flooring down, whatever. They aren't there to keep you moral, just to keep the building from falling down or killing people when it catches fire. This addendum is to answer the second part of your question; "is there a way to get around that?" That answer is "I doubt it," but if you make it so the city itself has no contract on the line, and your villain is defrauding non-experts and they absolutely love him, he can raise 20 million, spend 5 million, and vanish with 15 million, leaving behind a grand entrance that says "Job Center" that opens on an empty, dusty warehouse with cobwebs in the exposed rafters. Or the twist could be the "Stone Soup" fable; which is basically the plot of The Music Man: The con man generates so much excitement that the project becomes self-fulfilling: expectations were far lower than what he expected; enthusiastic volunteers make it all work out and nobody (but the IRS) ever looks at the money end -- and the IRS is not there to prosecute or expose any fraud. Say your villain has been promising he can stop the violence and reform one of the gangs. A bloody gang war erupts; and all the psychopathic leaders of both gangs end up slaughtered, one side murdered and the other side blown up the next day. The rank and file all call a truce, they will reform themselves, and come in for job training -- and our villain's corporate partners step in with new vigor, with materials, equipment and volunteer employees to help these gang members get it, to end the gang wars once and for all. It's great publicity for them, the villain is just the revival tent preacher with fire in his eyes and thunder in his voice. Then all your villain has to do is open the doors on that completely empty warehouse and he becomes a hero. Despite having the worst intentions, his Job Center succeeds and he is credited with turning around the lives of hundreds of Detroit youths. He even gets credit for stopping the gang war even though he had nothing to do with it. The city pins a medal on him, and MegaCorp: They may know many truckloads of money went missing, but it wasn't all theirs and it gave them a lot of free air time, so they don't mess with a good thing. [Answer] There are at least two problems here: ## Building officials, utility companies, etc. Your villain has to pay off the city's building officials, who are charged with making sure that the relevant [building codes](https://en.wikipedia.org/wiki/Building_code) are followed. Since corrupting building officials is a long-standing practice, there are safeguards against it, which mean that he needs to bribe a lot of people. If anyone is resistant to bribery, suspicion will start to spread, even if nothing is immediately provable, and journalists will start to poke around. Edit: The difficulty with corrupting the boss of the inspectors is that the fact that it's obvious a building is going up within the city. The inspectors also know all the building contractors. Unless their boss has a very good reason why none of them are inspecting it -- and building in a city without inspection is simply illegal -- the inspectors are going to suspect their boss of being corrupt. And the journalists get tipped off, and it all unravels. A factory needs utility services: power, water, drainage, etc. Putting in conduits for them is expensive and needs to be done at the start of building, because it's even more expensive later. If those are skimped, that's also suspicious, and it's the kind of thing journalists will check. Edit: The people at the utility companies will become suspicious if the utility provision during building is too small for a factory. They will have a pretty good idea what's required. The essential problem with this scheme is that it's trying to fool the competent, non-political people who keep a city running and safe. ## What about the machinery for the factory? A factory isn't just a building plus workers. The production machinery that goes in it often costs far more than the building. It needs to be ordered and deposits paid well in advance. The various manufacturers of appropriate machinery (who they are is dependent on what kind of manufacturing is to be done) will be keen to bid, and if no contracts are placed, or they're with unknown companies, that will raise suspicion. Edit: The contracts aren't required to be public, but part of getting a public subsidy for this kind of operation is the expectation that you will spend much of the money locally. So if the politicians don't see press releases about contracts being placed, they will become unhappy. Also, their political opponents will be on the lookout for wastes of the public's money. And bribing everyone gets too expensive. This scam isn't impossible, but it's rather risky. It's big and complicated, requires corrupting a lot of people, and there are a lot of ways it can be exposed. Edit: People have ben trying these kinds of scams ever since it's been possible to get public subsidies for building, which was likely during the Roman Empire. Systems have evolved to catch them. You need a more original crime. [Answer] Oh... so you need a shady land development deal that just happens to be beloved by millions and people will greatfully throw money at. Well, there's only one obvious person to model: WALT DISNEY! Now before you go grab your tourches and pitchforks, I'm exagerating a bit... but check out some of the things he did when buying land for what is today Walt Disney World. It was very hush hush (to avoid a sudden spike in the price of land near then podunk Orlando Florida, Disney had a bunch of shell companies purchase the land and when it was ready to develop, fold them back into Walt Disney Company. These companies struck a deal with the Flordia Government (before they were known to be Disney Companies) that allowed them to basically be free of almost all local and state level oversight... in fact, the only interaction Disney officially submits to on the Disney World Property is Florida Property Tax Laws and Elevator Inspection. Everything else is operated by Disney Staff and only Company men own home property on the land (rules require any changes to the property managment to be voted on by residents... the City of Celibration, Florida was actually given back to the state to avoid non-Disney staff from participating in voting). The property they control is 44 square miles... twice the size of Manhattan Island. If you want some good reading, look into the Reedy Creek Improvement District... Disney World is basically the coal company town on steroids... Happiest Place on Earth indeed. [Answer] my previous answer was deleted because not enough details were given but... here is an example, in Moberly Missouri, where such a "villain" scammed the city for millions of dollars by promising to build a sweetener factory and hire hundreds of people. <https://www.bloomberg.com/news/articles/2014-09-05/swindler-of-moberly-missouri-pleads-guilty-in-sweetener-scam> The other answers above do not describe human nature very well. We are not entirely logical beings, we are not robots. We have emotional and social components as well. Strong emotions such as hope (having a new factory for our town would bring so many new jobs!) or desperation leave people vulnerable, even entire communities to exploitation from an outsider. [Answer] Other answers have addressed the large numbers of inspectors and officials that would need to be bought off for you to even construct the "factory". But your problems don't end there. Suppose you somehow do get past all the inspections and get to the point where your factory is open for business. A factory has to have employees, right? Where are yours, and where are your (and their) employment taxes? Even if your city is corrupt, tax fraud at the state and national levels will be much harder to pull off. And all those employees should be having an effect on traffic and parking in the immediate area; unless traffic is already terrible (in which case people probably objected during the planning phase), eventually somebody's going to notice. And what about your consumption and output? A big factory should be drawing tons of power, even if you put solar panels on the roof (which doesn't appear to be a terrible idea in Detroit but probably won't run your plant by itself). Depending on what you claim to be producing, you should be drawing a fair bit of water too -- if nothing else, you'd need lunch, toilets, and maybe showers for all those workers you (don't) have. And sewage to go with. Depending on your processes, possibly also industrial waste that requires special handling. If you (claim to) be consuming and emitting all this stuff, eventually somebody's going to notice that the meter readings and/or utility incomes don't match. If you claim to somehow not need all that, environmentalists, reporters, and others will be beating down your door to find out what your secret is. "Building" a fake factory is already hard; "operating" it will bring you additional difficulties. ]
[Question] [ Centaurs are amongst us in modern-day society, but for the sake of decency they wear pants when in public. Whether or not a person, whether they are horse from the waist down or not, does so in private is their right to choose. From what I know about centaurs and the field of trouser engineering this carries a few problems: * Centaurs can't reach back far enough to pull their pants up over their rears and they don't always have someone nearby to help them, so they need some kind of tool that allows them to do this. Failing that, they need a system different from what humans use to fasten their pants. * Centaurs have tails. It is uncomfortable to tuck them into their pants, so there must be a hole for the tail. * Said pants must cover all of their legs, for both they and the humans decided that pants that just cover the hind legs would look silly. If possible centaur pants are a single piece, but if there is no other way there could be front pants and back pants: the front pants are put on first with a waist around the horse body that goes a bit towards the back, and the back pants have their waist go over this. It's like tucking your shirt into your pants. But instead of a shirt you tuck your pants into your pants. * In case that a centaur needs to use the bathroom, the pants must be able to be loosened so that they can use the toilet with ease. Toilet stalls and other such places are large enough to accommodate a centaur, but having enough space to completely remove the pants might be difficult (imagine removing your own pants in a rather small toilet stall). Whatever such a toilet might look like is for another question. * They have horse "bits" in the back, but not human "bits" in the front. So in the front there's only the usual muscle and skin there. * Hooves need not to be covered. These are pants, not (horse)shoes. But they need to fit over them. Somehow. Would such pants be possible? I know that they are more difficult to engineer (and likely less practical) than skirts or other such coverings, but I am looking for an answer that covers this issue like pants. [Answer] Given the complexity of movement in the horse's legs (walk, trot, canter, gallop), and the need to both allow movement of the tail and also quickly be able to go to the bathroom (especially if a centaur is vegetarian, and moving a lot of grass or oats through the gut), pants of any sort are going to be quite impractical. Centaurs who want or need to be "dressed" will have to adapt something similar to the barding used in the middle ages. [![Barding](https://i.stack.imgur.com/2n6IK.jpg)](https://i.stack.imgur.com/2n6IK.jpg) Barding covers the "unmentionables" while still allowing free movement of the legs, and does not impede the ability of the creature to void when needed. Barding could be fairly rapidly put on by the centaur, or more elaborate "formal wear" might require the services of a groom or valet. Barding also can be adapted to fulfill multiple functions. Military and police centaurs can have barding made from armoured materials for protection. In the middle ages, barding could range from leather (which could at least deflect sword strokes) to full metal armour that could stop arrows or even pole arms and other direct attacks. Barding can also be patterned, much like the heraldic patterns of the Middle Ages, although you can also imaging tartans like kilts, or the use of more elaborate patterns and weaves to indicate wealth and social status. Like kilts and skirts, there is an area of vulnerability to both "peeping toms" and to the weather (a strong wind might blow the barding up and over, but weighted hems should minimize that danger). So centaurs won't slavishly imitate human fashion on the lower half. In fact, centaur upper garb might be patterned in order to match the barding, rather than the other way around. [Answer] # Rather like this? [![enter image description here](https://i.stack.imgur.com/0H9Lv.png)](https://i.stack.imgur.com/0H9Lv.png) --- Caution: As necessitated by the question, I will need to make some references to bits of centaur anatomy that more modest readers might consider "private". Really, only three technical innovations seem necessary to make horse centaur pants as convenient as possible: 1. Red [suspenders](https://en.wikipedia.org/wiki/Suspenders). (You don't usually wear pants on your back, right?) 2. Bell bottoms and overall looser fit to get around hooves, knobby knees, etc. 3. A cutout at the back so that the normal horse centaur defecation method is unlikely to result in unsightly skid marks. # And now, a word about urination Perhaps surprisingly, urination is the tricky part. Males might be able to use some kind of string-activated trapdoor or zipper mechanism to facilitate urination (no, I will not be doing a sketch). Females will have a tougher time of it, and (similar to their human counterparts), might need to at least partially remove part of the pants pre-tinkle. Honestly, if I were a fashion-conscious centaur, I might just snake a catheter and enjoy my night on the town. # How to get into them? One leg at a time, baby, just like everybody else. It's going to be a bit of a circus act, no matter what. Without a helper, they would probably need some kind of "pants stand" that they could first fasten the pants to with their arms (and velcro), and then just step into each pant leg, fasten the suspenders (just within reach) and walk away feeling like a very clever centaur, indeed. # Other considerations Reproductive activity is--in my humble opinion--best done unclothed anyway, so I don't see any special concessions being required for that. Plus, more or less by definition, you have someone very motivated to help you undress (and redress, if they still respect you in the morning). [Answer] The biggest problem for centaur pants will be reach. Pants work well on humans because we can actually reach our own feet; Centaurs don't have that luxury. The human method of getting dressed goes something like this: * Hold pants in front of oneself * Step first foot through first leg-hole * Step second foot through second leg-hole * Pull pants up legs to waist * Zip, button, and/or otherwise attach A centaur may be able to hold his pants in front of himself, and he may even be able to step his front feet in, but he can barely see his back feet, never mind reach them to pull up his pants. Even an assistant centaur couldn't reach. Barring an embarrassing amount of assistance from a human, the entire act of dressing must be completely different, and thus the clothes themselves must also be very different. However, these pants are solely for looks; the horse part of a centaur can handle significantly worse conditions than humans, so these pants don't need to be warm, and can be made of light, tough material. Additionally, since these pants are solely for modesty, they don't need to cover the entire leg; they'll be more like shorts than actual ground-length pants. Not only do shorts make it easier to dress, they also won't get nearly as dirty since they aren't near the ground. Just before getting dressed, the pants will be open; they resemble a fitted sheet, with two holes at the back. The centaur steps his back feet into those holes, grabs the pants, then slides them up his back legs. When in place, the pants will cover from just above his 'knees' to right against his tail, perhaps even with a short extension over his tail. Then, the centaur folds the sides up and over his back, attaching them with a large zipper that goes all the way to his tail (the zipper probably has a hook that fits a stick, to push it all the way to the end). Next, the centaur folds the two front pant legs around his front legs and middle. They zip as well. At this point, the centaur is dressed, or at least his lower half is. These pants make it difficult to use the bathroom. There may need to be yet another zipper underneath, but that would be difficult to reach. As others have mentioned, a skirt or kilt for the rear portion may make more sense, though it lowers the modesty, especially if running. However, the addition of pockets to the pants will be amazing; pockets on the front and side could hold all manner of things. Cargo pants would allow a centaur to nearly pack all his belongings. Other styles would also be possible; sheer or net material for the non-essential areas (back, chest, stomach), additional material (on tail, or as a full-body skirt, or for longer legs - bellbottoms, anyone?), prints (like on t-shirts; the sides and back would be perfect for designs), and so on. Something tells me that zebra stripes may make a comeback. [Answer] [![Himie](https://i.stack.imgur.com/XCdce.png)](https://i.stack.imgur.com/XCdce.png)The anime, "A Centaur's Life", covers many of the questions on clothing and usage of a bathroom which are asked here. It also covers seat belts in transport. In Volume 2, there is an illustration that shows a Centaur is flexible enough to rotate the human body, so it faces over it's back, the fingers of the hand can touch the top of the tail. The bathroom, is more of a wet room, but with baths that can be stepped into. Normal shaped toI let bowls, because the Centaur has enough control to squat over it and move the horse tail out of the way. They are not eating large amounts of grass or hay, but similar food that the Japanese eat, so no, "mucking out". The series has been dubbed into English, and can be found on You-tube as well as the Comic translated to English. [Answer] not to get too deep into it, but the real answer depends on where the reproductive organs of the centaur lie, and, if applicable, how many there are. the only reason to cover both sets of legs would be having two separate sets of genitals at either end, one for the horse and one for the human. maybe just have a big skirt-like thing like they used on horse armor in the middle ages? i dont think i can finish this answer because i really want to not think about this at all [Answer] You could have a very loose fitting blanket with sleeves. The sleeves would be wide enough so that when lying on the ground, the centaur could step into each of them and feet would be touching the ground. The centaur pulls it up at the front, and then reaches down to each side and throws each side over his back (Perhaps they are a little weighted to ease the throwing) and using a strap pulls it up from behind over his tail - there is a hole or short sleeve for his tail to fit through which he can manage after a bit of practice. A system of draw-strings or long laces which are routed throughout the garment (so the ends are all reachable from or near the front) would be used to tighten the garment over his back and around his legs. To undress, he loosens all the laces and drops down and steps out of the front. There is an elastic component which pulls back the entire garment once the laces are undone and released pulling it back over his back. After that it's just a matter of shaking it off his hind legs. To use the toilet, there is a long zip along the bottom with a strap, which can be pulled either through the middle of his front legs, or over his back to open or close. Not really sure how he wipes though... [Answer] I believe that centaure pants would be more akin to horse barding with shin guards that match. then that horse barding would have snaps to attach to the tops of the shin guards. or something like this? [![My little master chief](https://i.stack.imgur.com/wQQbd.png)](https://i.stack.imgur.com/wQQbd.png) [Answer] Well, we could go with no pants, and more of a horse blanket approach, which would probably more comfortable and fashionable for the centaur. Centaurs would need as much and probably more food than a normal horse, so defication would be a problem. A horse blanket approach would make it so that the centaur can deficate with no problem. Or again we could do a solid pants idea, but it would only cover the hind end of the centaur, because even though centaurs have four legs, pants are used to cover the private area, thats why shorts are acceptable with humans. [![Horse Pants](https://i.stack.imgur.com/wUall.png)](https://i.stack.imgur.com/wUall.png) [Answer] Possible sure. If you had a complete lower body suit for your centaur that could be completely unzip from the back and if you're centaur had a couple people helping putting it then sure it's possible. Would it be practical? hell no. For one thing we require the help of humans or some other creature to put on. If the centaurs feel self conscious about their feet. They might try something other than pants to cover themselves. Maybe some kind of sheet or animal hide that long enough to reached there hooves. They could put it on what the help of only one other centaur if it had a buckle on the front it could be secured around the Centaurs human hips. There'd be a space in the back so the Centaur could use the bathroom without taking it off. This would probably resemble more of a dress then pants but it would be more practical. ]
[Question] [ We are in a medieval setting (think 16th-17th Century, Western Europe), in a country of a size equivalent to modern Switzerland, and reasonably populated for the time. A new King gets on the throne. He has a passion for Arts, and decides that he should put all the Kingdom's resources towards producing and spreading artistic realisations. For that, he does the following * limits agriculture, * disband the army, * creates schools for different Arts, * promote cultural events, including international ones, * create some re-distribution system for the more successful artists to help the (as of yet) less sucessful ones, * etc. His idea is that with paintings, scuptures, revolutional architectural design, tourism, etc. the country could get enough income to actually pay for the food and other commodities import. He manages to convince some of the religious leaders that artistic creation helps the Faith and Church, and they agreed to be supportive of his goal. Considering the views of Arts at that time, can that King achieve to convert his country to an essentially mono-industrial country, namely Art-driven? Note that "Science" and Knowledge are also acceptable for him, so he could also build universities, etc. [Answer] A big problem that I can see with this arrangement is that while people back then did purchase and appreciate art, they usually needed the artist to be nearby. For instance, portraits were (and are) popular, but before the invention of cameras you actually needed to go to the artist, or have them come to you, to get your portrait done. Since you're rich, you're probably going to invite the artist over; thus, while you may want to hire a painter from this artist nation, if people all over the world hire all the nation's painters, your nation is going to be empty of painters for most of the year. The same goes for sculptors, architects, musicians, actors, etc; they're going to need to physically go to wherever they're creating this art, otherwise things will become needlessly difficult. And since travel time was pretty long back then, people are going to have to wait a long time for their mail-order artists to arrive, and the artists themselves are going to have limited incomes because so much of their time will be spent travelling. Thus, not only will your nation of artists get fed up with this terrible lifestyle of moving all over the world simply to pay enough taxes to support a country they hardly get to visit, but other nations are also just going to opt to use local artists for most of their work. And if you think about it, there's really no reason to keep artists in your nation; they might as well emigrate. The best way to support artists in your nation is to be a nation that can pay for artists. Fill your cities with rich people, and art will follow, not the other way around. For instance, look at the rich Italian families such as the [Medicis](https://en.wikipedia.org/wiki/House_of_Medici): these people gained wealth and power through business, and they used that wealth to foster the arts and make Italy the center of the Renaissance. The more rich families and businesses your country has, the more artists it can afford to employ. [Answer] No, it is not. From the way you're approaching the situation I think you're not considering that the world in the 1500's had a radically different view on life and inter-nation relationships. In this day and age borders in Europe are pretty stable (as in European nations no longer go to war with one another over land in Europe), but that was *not the case* going back as recently as the Second World War. (The whole Crimean situation is not being taken under consideration right now). Political Landscape Europe was divided into many states, and city states, some of which held their allegiance to a monarch only by a very frayed string. The concept of a "nation" did not really exist as it does today. Italy, for example, was not one nation, but composed of many city states, each of which was populated with Italians, and each of which slaughtered the other at the slightest opportunity for gain. Furthermore, a lot of ruling families were related by marriage, and/or had long-lasting feuds with one another. The reason that you'll find so many castles in Europe is because they were needed, and badly. War, at the local or continental level, was constant, with nobles trying to capture neighboring city states, maneuvering politically and militarily to annex the lands of a rival, or simply avenging an insult. It was 100% normal for a city state to change leadership several times in a decade. The show "The Borgia" (the European one, not the North-American one) really gives great insight into how fluid alliances, borders, and motivations were at that time. It was all quite chaotic, with monarchs fighting one another, then ganging up on a third rival only to fight each other once more. Culture The value of human life is always relative. In the West we like to think that each and every one of us is a precious individual with the right to live a free and happy life. Our hypocrisy is easily exposed when we cause thousands of civilian casualties in countries like Iraq, and find that we don't really care that those people die. It's in the media, we ooh and aah for a few days, then get sucked into choosing our next smart-phone, etc. Well, in the 1500's the value of a peasant's life was somewhere in the negatives, and the peasant knew it. You look at a noble the wrong way and he WILL skewer you, with little to no consequences for doing so. In that day and age personal insults were a perfectly legitimate reason to kill someone (in a duel, for example). However, power structures were also very much based on family relationships. If you duel and kill the wrong youngster in the local tavern, you may soon find out that he was the cousin of some high-lord in a neighboring city-state, who will now use this incident as an excuse to launch a campaign against your own city. Standing Army First of all, any country with no standing army is inviting invasion. Some diplomatic maneuvering may save you for a while, but sooner or later (with my bet being on sooner) your neighbors are going to start stripping pieces of land away from you. Furthermore, at that time nations did not necessarily have a national army in the sense that we do today. Individual lords and other nobles would be entitled (or even required by law) to have a certain number of infantry and cavalry under their command. Having too few, or too many was seen either as a weakness, or as a provocation respectively. Conflict The fact is that at that point in history a rivalry between two local noblemen over who's workers gets to cut logs in which forest could easily result in an armed clash before the matter ends up being settled in front of the king. In fact, by the time the officials are informed, the king summons both nobles over, they arrive, a decision is made, and they both go home and implement the ruling (or not), months or even a year may have passed. > > Example: A forest straddles the territory between two baron's lands. Some very fine trees grow in that forest, which are perfect for construction projects which both lords are heavily invested in. > > > > Barron A's woodcutters venture deep into said forest, close to Barron B's land in order to cut down the finest trees (into "contested" territory). They commence operations and are at it for a few days before Barron B's woodcutters run into them. The two groups come to blows over who has the right to cut down those trees. > > > > Barron B is outraged & sends his captain and several men-at-arms to evict the "invading" woodcutters. In the mean time, Barron A sends his own troops to protect his operation. The two groups meet in the clearing and face off. Barron A's troops claim that the other group is trespassing, and vice-versa. Heavy words are spoken, and both captains back off, but only just. Barron B's captain, however, launches a surprise attack in the night. Archers, with fire-arrows kill several of Barron A's troops and woodcutters, and they destroy much of their equipment. > > > > Barron A now sends a complaint to the King, as does Barron B. However, not wanting to be judged as weak, he also sends troops to torch some of Barron B's watch-towers, as well as seizing cattle and sheep worth "the price of what we lost". > > > > The conflict keeps escalating, to the point that when the King finally steps in some weeks later one Barron's castle may already be besieged by the other. > > > Agriculture & Food You're dealing with a time in history when food shortages, and starvation were not unusual. In the winter, with lots of snow on the ground (the Earth was experiencing a global cooling event in the 1400-1600's), some communities could be isolated until the snow melted. It was not entirely unusual for most of a village to have (mostly) starved to death during the winter months, and only have this be discovered in the spring. Here's some facts: > > There were no fridges, no canning, and no great ways of storing food. > > > If you slaughter an animal, you have to either salt it, smoke it, or just plain eat it. Even if you do try to preserve the meat it will still most likely go bad in the summer, or simply get eaten/spoiled by rodents, or other pests. > > Transporting food is not a trivial task > > > Transporting food in the summer months is not a good ideas as it is almost guaranteed to go bad on the road. Conversely, in the winter it's very difficult to move around, and freezing to death on the road was not unheard of. > > Not having food on hand is a huge vulnerability > > > Anyone wishing to invade your land would first cut off your food supply. By relying on imports (which is insanely unrealistic for that time period anyway) you're simply making it incredibly easy for them to starve you into surrender. Art & Culture Having a standing army, feeding your population, attracting artists, and pursuing scientific knowledge are not mutually exclusive in the least. But be realistic about the people you're dealing with at that time in history. The vast majority of people (even today) have little to no culture, never go to an art gallery, don't listen to classical music, etc. They come home, crack open a bottle of beer, and sit down to watch their favorite sport or show for the rest of the night. The common peasant back then was no different: they didn't care about the latest, flashiest painting hanging up in the King's parlor, they just wanted to make a living and survive the next winter. A drought impacts them. A new tax impacts them. The latest poem that the King enjoyed over drinks with his buddies is of no relevance to them. However, try telling them that they can't farm anymore, because they are now expected to write poetry themselves. Food will be provided, in varying quantities, as available, and their only concern is lounging around and creating "Art". That's a great way to sink a nation if I've ever heard one. City-States There's a reason why the Renaissance took place in the city-states of Italy. Because the political landscape allowed rich cities to focus spend money on artists and other "frivolous" pursuits while having enough gold on hand to hire as many mercenaries as necessary to keep them safe. Even then the many nobles still had their own armies and fought not only neighboring cities, but also each other on a regular basis. However, since the scope of each monarch was more limited, and their coffers quite full, they were able to much more easily allow a passion for arts and the pursuit of knowledge to grow. Gearing an entire kingdom (the size of Switzerland no less) to do the same is not possible at that point in time. People need to be fed, and protected, not only from outside threats, but each other as well. Furthermore, at this point in time it's quite common for a noble to pursue a higher title by murdering his betters, and monarchs were constantly being deposed. A king would be quite foolish to disband his own troops and trust purely in the obedience of his nobles, and the generosity of his neighbors, not only to not invade him, but feed his people. [Answer] It would be risky for a country to focus on one industry alone generally. * As pointed out in Micheal's comment, importing food would be difficult since the time period you are talking about is even before the invention of the automobile, so no quick method to move stuff around. Another problem would be food preservation - refrigeration was not available during that time, either, so most foods would spoil fast. Of course some would withstand the journey, wheat, rice, grain, potatoes maybe, but your nation would have a very limited selection of foods - they might intuitively focus more on getting more or better food instead of indulging in artistic endeavours. * Nations with no armies are certainly possible. There are such examples today, but it would have been far more difficult 500 years ago when communications were not fancy. The conflicting parties might have an easier time sending in the army to deal with the problem instead of sending in the leaders to resolve the issue. In addition, if the pieces of art really do become valuable enough to be bought by neighbouring countries, they will certainly be valuable enough to steal. * The lack of an army I would guess would also mean lack of servicemen like police, firefighters, medics since everyone is involved in arts. It would be unfeasible for a country to expect foreign aid in terms of human resources in cases of natural disasters. * The redistribution system would likely face the same end communism has - a successful artist will sooner or later refuse to support a non-successful one, especially having in mind some will never be successful - not everyone is cut out to be an artist. * An economy based on arts would fluctuate a lot. A piece of art does not have a static price, it is extremely subjective. The other nations, if they are in times of peril, would likely no longer import the product. Even in times of prosper, an entire nation of artist might saturate the market quickly so the demand would flatten. * Other nations will likely also have their own artist. They might prefer their own people instead of yours, their art will reflect their culture, their trends, they relate to it more easily. * Organizing an international event during these times would have been near impossible. It is hard enough today. Even local events would have been hard to organize with no fast communication line. In essence, having such a country is not realistic. It might work in a fantasy setting, but there are many issues if going for realism. [Answer] Yes it is, if you are willing to define 'country' a certain way. The nation will have to be: * Small. It would have to be a city state * Exists in a heavily populated region * Powerful in a non-traditional manner * Variable understanding of the "Arts" Some depth. Bullets 1 and 2 go together. For a geo-political entity to be this specialized it first needs to be small, particularly in a medieval setting where surpluses of essentials were not the norm. To realize this group of specialists the surrounding nations will need to support Artlandia with food, raw materials, protection...basically everything. This means the surrounding lands need to be fairly wealthy because no one purchases art if they are struggling to eat. By non-traditional power I mean non-military power. The city could be a banking hub, religious center or perhaps they have technology that keeps potential attackers at bay. The most obvious real world example that comes to mind is Vatican City...now its not an exact parallel because the pope had his own army for a good portion of the middle ages, but it is close. Essentially with this line item I am telling you there needs to be a reason that surrounding nations do not just annex the city since it is poorly protected. I think the most realistic scenario is that the city is the center of a hierarchical world religion. That way you have a single religious figure that can help keep the surrounding nations at bay. At the same time making the city a center of learning may afford them some technological protection as well. Maybe they have some ridiculous weapons that the surrounding nations can't compete with. If you throw being a neutral banking hub on top of that it doesn't hurt either. The last bullet simply reinforces a point you made about what is considered 'art'. If you include only the traditional arts, painting, sculpting etc then...no you are going to struggle. If you include religious, education and scientific institutions in your nation you bring much more variety and can bring money in from outside the country in the form of students, travelers, merchants etc. During a time of relative prosperity for the region this seems like it should be a viable scenario, maybe not completely practical...by workable. If things go downhill though...it probably ends badly for the city's independence. Keep in mind a city of artists can't actually function. You will still need all the basic services of a city met. That means you will have services workers, inns, street cleaners, gardeners, sanitation workers, basically all the stuff that makes a city function still has to be there. It may be better to consider your city a Seat of Learning rather than a nation of artists and if the city is that well off it is going to be difficult to keep people with other specialties from moving in to enjoy in the prosperity...it takes a lot to run a city day to day and that would all have to be present even if you don't have city farms or a standing army. [Answer] If you replace Artist with Artisan (which is more fitting for the mediaeval) and not on the national level but on the civic it is not only possible but it happened. Even painting was considered a craft. The concept of Artist came with the early modern. Milltowns, Jingdezhen, Dresden, Delft and college towns are all good models. The logistical systems for groceries just don't work for nation-sized mono-industry countries. Someone has to grow the perishables. I noticed you are allowing some agriculture so they would need wine and grain imports. A city-state could work. One that trades china or miniature paintings for the food they don't grow with the neighboring villages. Or Islands if you put in on an island in an archipelago you could ameliorate the defense and transport problems. So Yes you could build a medieval [city] state built on the export of aesthetic goods. Your story could also have pirates. Look at Bali they have a very intensive Art culture. Probably because of the excess calories from the rice production and their geography protects them from invasion. [Answer] Your country can import food and manufactured goods, but who will cut the artists' hair? Who will teach their children? Who will mend their clothes? Who will clean their houses? Who will give them medical attention and nursing care? Who will tend to their spiritual welfare? There are many, many services that can't be imported and have to be delivered on the spot, and so no country can be mono-industrial. ]
[Question] [ I'd like to have freights transported across my world by airship heavy cargo haulers with some passenger variants as well. Imagine the scene with such airships soaring above the land, floating gracefully through the celestial dome propelled to where they are headed or perched on special docking mechanisms sticking out of the landscape and creating contrast. Do you think that they could be plausible in a hard-science/speculative but not fantasy setting? For additional information, the planet's gravitational pull is about 0.9 earth Gs, atmospheric pressure 1.5 atmospheres and the civilization living on it would have the technology to synthesize ultra-light materials (like carbon fiber, carbon nano-tubes and graphene) in considerable quantities as well as building modular nuclear reactors small and safe enough to be present on board the ships. For example, do you think a combination of blimp, VTOL, ultralighteight materials and nuclear technology could achieve such feats? The following image is from Simon Stalenhag to better illustrate the freight haulers concepts, taken from imgur: ![Simon Stalenhag freight hauler concept](https://i.stack.imgur.com/fcgIL.jpg) And here is the compilation: <https://i.stack.imgur.com/S6aOV.jpg> And this one for the cruise ship concept taken from Pinterest: <https://i.pinimg.com/564x/16/a0/32/16a03200a6adf4f1baaea437f137bba2.jpg> For a real world reference here is a video illustrating a concept for a nuclear powered aircraft carrier bomber developed during the cold war, which apparently had VTOL capability too: <https://www.youtube.com/watch?v=d7KgjObskvM> About the nuclear reactors, what I have been thinking about is based on the recently developed modular designs, combined with the technology to use thorium as fuel rather than uranium and molten salt. [Answer] # Possible with minimal hand waving Every few years, there's breathless coverage of the some airship startup that heralds lighter-than-air craft as the next big thing in aviation. A quick search of Popular Mechanics turns up articles like "[4 New 'Blimp' Designs Bring Return of the Airship](https://www.popularmechanics.com/flight/a2445/4242974/)" (2009) and "[Why the Return of the Airship Makes More Sense Than Ever](https://www.popularmechanics.com/flight/a28925834/airships-hindenburg-comeback/)" (2019). So there are people who believe that the technology we have today could support pretty awesome airships. You're positing the existence of ultra lightweight materials and powerful nuclear reactors for power. Having large amounts of power without a lot of weight would let you build some kickass blimps. One restriction to your last image is lifting capacity. Even with a lower gravitational force, you'd need a lot of hydrogen to get a big craft off the ground if your atmosphere is like Earth's. One workaround would be having the lifting gas only support some of the weight and use engines to provide additional lift. At your technology level, you could use either [ducted propellers](https://aviation.stackexchange.com/questions/27416/are-ducted-fans-more-efficient) or [electric jet engines](https://interestingengineering.com/this-electric-jet-engine-could-lead-to-carbon-neutral-air-travel). [Answer] ## Plausible Airships are the dream of many a sci-fi / futurist / what-if worldbuilding project! I think you hit on the main points, materials, high enough tech, nuclear power source, all electrics. Just about every detractor of airships points to the Hindenburg disaster and the airships that were designed in the 1920s and 1930s. That was a century ago! Hindenburg itself flew dozens of times without issue and there were other ships in service. Had the Hindenburg not exploded, or had the news coverage not been so tear-jerkingly emotional (Oh! The humanity!) it's quite possible, probable even, that airships would continue to be used in some capacity and the technology would evolve sufficiently to overcome various problems. Keep in mind that early commercial jets also had their problems, the Comet coming to mind immediately. Yet we didn't give up on jets and as of now, air disasters, while rare, are not technological deal breakers as was the 1937 disaster. I'd argue that your project is perfectly plausible given the technological and materials advances. [![http://ib.frath.net/w/Aeroscrafts](https://i.stack.imgur.com/xz9JO.png)](https://i.stack.imgur.com/xz9JO.png) [Answer] One major problem with airships of any kind is their size. Assume hydrogen as the lifting gas: a rule of thumb (that will get you within a few percent of the actual numbers) is that to lift 1 kilogram of mass--which would be the airship itself plus payload--you need about a cubic meter of hydrogen or helium. Hindenburg had a volume of 200,000 cubic meters, and a useful lift capacity (ship + cargo) of 232 tonnes. The ship itself massed 118 tonnes, which left 114 tonnes for fuel, passengers, supplies, ballast, and so on. Let's say modern materials get it down to 50 tonnes, which then gives you a total 182 tonnes for everything else, including things merely needed to fly the ship, such as fuel and ballast. Regardless, this is what this looks like in comparison to modern aircraft: [![By Giant_planes_comparison.svg: Clem Tillier (clem AT tillier.net)derivative work: Timmymiller (talk) - Giant_planes_comparison.svg, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=13920306](https://i.stack.imgur.com/gvR3D.png)](https://i.stack.imgur.com/gvR3D.png) The freighter version of the 747-8 can carry 140 tonnes of cargo, which puts it on par with an airship the size of Hindenburg. Now look at the difference in size. That has repercussions for everything from flight paths to ground handling because of the wind load it experiences. Just as a for instance, once a plane lands, except if the wind gets into storm force ranges, you don't have to worry about it. For an airship, anything over a stiff breeze may require constantly running the engines just to make sure it doesn't snap the mooring lines. Imagining anything larger is, well, sort of hard. [Answer] Plausible, with a different planet: 1. We need a planet where traditional long range transport techniques aren't nearly as good as the options on Earth. How about a rather dry, very geologically active world where much of the surface is mountains of various ages and little of the surface is oceans or large rivers. Ships only do oceans and running trains through mountains is very expensive. 2. Lets improve the lift: Make the atmosphere considerably more dense. While it wouldn't be survivable to a human there's no reason a creature couldn't have evolved to live in such a location. Now, how about power? At first glance a nuclear-powered airship makes no sense, you can't haul the shielding and thus you fry the crew. Lets try a different approach, though--how about shielding our ship with the atmosphere itself? The reactor dangles on a long cable below the airship. This is not an insurmountable obstacle to landing--airship landing platforms have deep holes into which the reactor is lowered. The holes are well away from the platform itself--the airship approaches, a line from the airship engages a winch that pulls it in until the reactor is some feet underground. At that point another cable is hooked and the airship dragged down to the actual station--it remains far from it's reactor at all times. Lets say the planet is at 50 atmospheres--at that point the halving thickness of air is 10 feet. If your reactor cable is 1000' long that's the same as putting 20' of concrete between you and the reactor. As for why they went nuke rather than solar--batteries are heavy, thus substantially decreasing the carrying capacity of an airship that can operate under clouds or at night. Beware that the smaller the reactor the higher grade fuel it must use--I don't know how small you can get before you have fuel that could be diverted to bombmaking. [Answer] They are viable, even on earth without all those boosts you imagine. ## some blimp pros for earth The energy efficiency of blimps is on pair with railroads, it takes 3rd place this way - sea ships(0.3), railroads(1x), blimps(2x of railroads energy-wise), trucks (4x), airplanes(10-30x). Comparisons are very approximate and rely on that I remember the number for blimps correctly and didn't screw my calculations back then and that blimps move quite slow(20-40kph). Blimps are one and pretty much only one which can use high(8-20km) altitude [Jet streams](https://en.wikipedia.org/wiki/Jet_stream) having some "free" energy for long-distance hauling. Its next competitors are solar-powered airplanes, but those aren't that impressive fragile and have other problems including complexity and EROEI. In the capacity to lift and deliver bulky cargo - blimps are the only ones that can deliver something like oil platforms from the assembly point to installation point in one go(ignore the fact it is built in the same places where ships are, it is just an example of capacity and size). And not only those are a problem, and it could be an improvement if we had such capacity. At the moment it is - or a complicated transporting problem, or requires all kinds of moves from design to installation procedures. Blimps are the only cargo transport that can cover 100% of the planet's surface. Blimps do not require loading unloading at coast ports and can deliver directly to a consumer, faster than a sea ship, with less energy spent than a ship(if we rely on jet streams, okay okay I hear you solar panels, not necessarily a great idea but "free" energy anyway) and if we consider that from a port this cargo has to be delivered further by trucks (often) or railroads(also often) then energy efficiency can be even higher and maybe even sufficient to compete with railroads or maybe more(no loading unloading procedures, delays, etc). If one needs a port for cargo for blimps then such port can be built anywhere, you can choose an optimal place for that type of cargo. Seaport, for bulk cargo transporting, is a huge system - with roads, railroads attached to it, with places to store cargo, load-unload and places for it are limited to the coastline - we did cope with that but it does not mean things could not be better. In a time when we begin to see bulk gas transporting - blimps can be used for that, and it hard to tell who's the winner - ship or a blimp, so besides bulk cargo transporting it another one where blimps can compete with sea ships transporting directly, again cutting corners (literally) by not being bound by channels, and deliver directly to gas storages, directly from gas "wells" meaning cutting pipes, deliver faster(2-3x) than doing so by ships, be flexible and more responsive for demand changes. The pipe is a winner for fixed places hands down, but there is not always a pipe, and one can test and build up production to a level when a pipe investment makes sense - so more flexibility and blimps rather win over ships. * the probably least useful case for the op, with modular reactors and such, as the same reactors can be used for what most of that gas is used for. City to city transportation can be more efficient - essentially flexibility of a helicopter for a price(energy-wise, delivery) 0.5x of a truck, with direct routes, higher loads(more than 40t), more efficient lower loads(0.1-1-5t), better prospects of making drones out of those, etc - those can be attractive points. ## op's materials, energy source The importance of different points changes slightly, due to reactors' use, but overall it is the same. Gravity and density of atmosphere have minimal influence on all those points. Stronger cheaper materials are beneficial, but so are they for other things, I mean they are not a game-changing factor and not required but sure they are a good thing. ## reactors Given that nuclear reactors don't work for heavier-than-air flight, lighter-than-air flight seems even less plausible. The high surface area of lighter-than-air vehicles does make solar a more viable option, though. – @jdunlop This one is wrong. Reactors definitely are more plausible for blimps. There are few reasons for that - liftoff energy consumption may be low percents of full throttle, while on airplanes it is one of the intense moments. Not necessarily a big deal for combustion engines, but reactors do not like jumps in power for many reasons, including for reasons of processes of chain reactions happening in nuclear fuel. The difference is not necessarily huge, but a similar difference is enough to not have turbines on bikes and cars(it is not only it but one of them). Power to weight ratio is less important for a blimp, the range is wider - if a blimp can lift one, then it does not matter that much if it delivers 1MW or 50MW - the difference is cruise speed, but not the ability to fly if the airplane does not have sufficient power it just can't take off, even if this power would be sufficient to hold some cruise speed. Solar panels for airplanes and blimps are not necessarily such a cool thing - there are airplanes like those so it can be seen(quite fragile construction to which op's materials could be a great help btw), for blimps it may be a better option than for airplanes, but it hard to tell if it better than some jet stream sail as an example, which can work 24.7 without batteries. In an airplane, one can't distance himself from a reactor, while on a blimp there is more distance between the crew and a reactor, which may mean lesser shielding requirements(thus mass, etc). A blimp can tow a blimp, from start to finish, essentially making an external engine, this is used for ships, but airplanes, it is used for gliders but beyond that, it is even harder to imagine a Boeing size thing towing another Boeing - but a blimp towing another blimp, not a big deal. More airplanes did crush than blimps burned - (anonymous) ## misc Safety-wise it is hard to argue what's better, essentially we are noobs blimps making and did perfect designs for ships and airplanes for more than a hundred years. And despite that there are spectacular design failures for ships in history('70s, 80's, in essence, worse than titanic in terms of mass/cargo loss), so as cruise ships incidents in this century. Airplanes are not an exception, we all know that, airplanes do have some problems landing as well and it is hard to imagine it going away any time soon(it can, with better technologies, like smart matter but when it happens is unknown) Better materials make blimps more useful already, and some are in limited use for inspecting and such as a replacement for ground vehicles and helicopters. This is far from potential it has, but it is, even more, a sign that blimps can offer unique advantages. So as for safety materials are an improvement and not only materials but other technologies like detecting gases - nothing of that was possible back in the days but still, some blimps of that era had million+ km's under their belt. They tend to descend than to crash is definitely more friendly for reactor placement, not as good as tends to sink in water, but still. Mooring lines - what about a 3km landing strip, eh?. Airplanes usually do not idle in hangars they fly in and out as much as they can - so storing is overrated. Autopilot for airplanes works well enough, take-off and landing are still a procedure but great improvement here as well, for blimps drone-like capacities are even easier and that (combined with Starlink) can offer unprecedented opportunities, and if you still care about storing problems - here as well. So in general with or without reactors and more new materials blimps look like an attractive idea, there are interconnected factors why it does not happen as of today, including we did bend our processes to not need them, but it does not mean they have no chance for resurrection, and for places where their development wasn't abandoned and they continue to evolve and processes were shaped for their use - most likely our system would be unimaginable and not viable. If someone can beat sea transporting then they will have all the chances to spread that technology to other places - they will have technologies and money for that as SpaceX did. And one of the avenues is transporting gas overseas and from small places. [Answer] Operating in any kind of windy or turbulent conditions is a major practical constraint, even for modern airship designs on Earth. Wind that moves at a constant speed at a given altitude, such as the jet stream, is not a problem, and high-altitude airships can use such currents to their advantage. The problem occurs with turbulent air or with winds near the ground. One possible solution to this constraint is to construct a world in average wind speeds are much slower than they are on Earth. The major question you will have to address is why airships have come to dominate air travel in your world when heavier-than-air craft have proven to be so much more practical in our world. If your world has a sufficient level of technology to make airships feasible, then it also would have the science and technology to make airplanes feasible. Perhaps the world once experienced a world war that was facilitated by high-speed airplanes and rockets, and such technology is now banned by international law or cultural taboo. [Answer] ## Probably not on Earth We can't significantly improve on WW2 era airships here on Earth, because those designs already used the best lifting gas allowed by physics. H2 is the lightest atomic gas - can't get smaller than one proton per nucleus. This puts a hard upper limit on the lift you can generate, which makes practical airships difficult. ## Think Titan Titan's atmosphere is thicker than Earth's, which means you'll get more lift for the same lifting gas. This is good. Also good is that Titan has significantly lower gravity. Between these two factors, you should be able to build much smaller and more efficient airships. Since there's very little O2 in the atmosphere, you don't need to worry about hydrogen explosions either, so that's a bonus. The view of the endless hydrocarbon dunes is going to be... spartan, not unlike your sample images. But probably still beautiful. [Answer] The fundamental problem with airships is that they have a large surface area, and need a large input of power to make progress against a headwind, or even a side-wind. This makes them very inferior to heavier-than-air aircraft for moving passengers, or even cargo, to a predictable timetable. (It also makes them slow, even in good conditions). Nuclear-powered airships? ... er, no. The less fundamental problem is that hydrogen is problematically inflammable or explosive if air gets in, and helium is problematically expensive. For getting heavy cargo to a remote location without roads, or for heavy lifting where it's difficult to deliver a large enough crane, an airship has some merit. Here, getting the job done at reasonable cost can afford to wait for a day with low wind. It's possible that the Hindenburg disaster is so deeply etched into our memories, that nobody can get the concept of a large hydrogen airship past the money-men. Maybe elsewhere, with modern materials and no adverse history, it would fly. Incidentally a methane-filled airship would need about twice the volume of a hydrogen-filled airship for the same lift, but methane is far easier to contain without leaking, and far less of a fire or explosion hazard if there are small leaks. [Answer] One big issue is load management. You go from A to B with 100tons. At B you either have to get an equal mass load, or you have to vent lifting gas. The easiest way to do this is to use water. You can load it with pumps, discharge by gravity. This is a major logistics issue if you are delivering to some place in the middle of nowhere. They have to get tanks ready that hold as much mass as what you drop off. I can see the merit in floating aerodromes on medium size lakes, or protected bays. You anchor, then a barge positions itself to receive 12 seacans by winch. The barge on position gets lines from the airship so there is no reaction as the cargo is released. Meanwhile the airship drops a hose and is pumping water into ballast. Tension meters on the ropes indicate how close to balance the airship is. In flight you don't have to exactly balance buoyancy an weight. If the lifting gas is in bladders, you can pump it into high pressure storage tanks. This is useful for minor changes. In flight you can also be slightly heavier or lighter than air and compensate with the bow pitch. You have to get this fairly close to spot on at landing time. One of the options for lifting gas is hot air. High tech solution: Make the outer shell out of a mixture of glass and carbon fiber that is foamed in a vacuum. Put a reflective layer of aluminum on both faces. A 1" thickness of this would have a high R value as well as being impressively strong. Carbon fiber and resin would make up the frame, much like a graphite bicycle. The lift of hot air is roughly p \* K/Kambient. Where p is the density of air, K is the temperature inside the envelope, and K ambient is the temperature around you. If K is twice ambient, so 580 K in the envelope you get about .6 kg of lift per cubic meter. This is about half what the same volume o H2 gets you. The win on this is that your ballast problem goes away. The lose is that you have to regulate the temperature. 1" of multi layer vacuum would keep heat in quite well, but you would need to discard hot air replacing it with cool air whenever you dropped a load. You will also have issues when you descend from colder air to warmer air, as you lose lift. Some ballast operations would be necessary to increase lift FAST. Or if the lifting gas is fresh, you could directly burn propane inside the envelope to raise the temperature in a hurry. Landing might be semi-automated by running somewhat bow-light, then dropping a 500 foot rope at approach. This is attached to a winch that pulls you in to the mooring mast like big fish. Mooring masts have to be sturdy enough to withstand whatever normal storms you have locally. Call it 70 MPH for non-coastal (non-hurricane) areas. These are not going to be tall graceful spires but more likely to look like concrete obelisks. Severe storm warnings would result in one of: * Airships flee out of reach. * Airships are deflated and anchored to the ground (blimbs) * Airships are parked in underground hangers (expensive) Read up on other airship crashes. The navy ship Shenandoah is a good story. [Answer] Make Helium abundant. Perhaps there are pockets of helium underground, trapped during some exotic process in the past? Much like our oil, gas and coal. It is trickling out, and is generally seen as more of a nuisance than anything. You could make blimp repair-hubs around large reservoirs, even in places with bad roads and such.. [Answer] I've done a lot of thinking about airships. See: <https://worldbuilding.stackexchange.com/questions/tagged/airships> Short answer: yes it's entirely feasible. There are no good alternatives to helium (apart from <https://en.wikipedia.org/wiki/Vacuum_airship> which will fit some worldbuilding scenarios but not others), so you should make sure your planet has abundant helium resources. IRL, helium is harvested along with natural gas deposits underground. Alternatively, it can be harvested from space. <https://www.flying-whales.com/solution> build a transport ship called the LCAT60T with the following specs: it can haul 60 tonnes (a Boeing 737 hauls about 20-23 tonnes), is 200m long, has a cargo bay that is 96m × 8m area and 7m high The ML866 is a similar cargo airship: <https://en.wikipedia.org/wiki/Worldwide_Aeros_Corp#Aeroscraft> and is 169m long, hauls 66 tons. The same company ultimately plans to build a ML86X with a length of 920 feet (280 m), a height of 215 feet (66 m), and a width of 355 feet (108 m), with the capacity to carry 500 tons. Note that all these carrying capacities are dwarfed by trucks, ships, roads. There are container ships that can carry over 500,000 tonnes. But airships have their use cases, like remote landlocked areas (remote=no roads or rail, landlocked=no waterways), or for the romance of it. Feel free to ask me follow-up questions, as we're working on overlapping projects. [Answer] This has been attempted in Germany in the 90ies and failed mostly for financial reasons. I don't see why it would be technically impossible: <https://en.wikipedia.org/wiki/CargoLifter> > > "This service was based on the development of a heavy lift airship, > the CL160, a 550,000 m3 (19,000,000 cu ft) vessel designed to carry a > 160 t (160,000 kg; 350,000 lb) payload." > > > From the German article about the airship itself, translated with DeepL: <https://de.wikipedia.org/wiki/Cargolifter_CL160> > > Description CL160 was designed as a keel airship. The keel was to be > made of carbon-fiber-reinforced plastic and to carry quarters, load, > tail unit and propulsion extending from the bow tip to the stern. > Eight General Electric CT7-8L shaft turbines of 5882 kW (8000 hp) each > were planned for the latter, half of which were to be used for > steering only. Many details of the design remained unresolved, but > some components had been manufactured before the bankruptcy. > > > A fundamental hurdle to the design of large cargo airships is the > extensive buoyancy compensation required for loading and unloading the > airship. A load exchange method was envisaged for the CL160, which was > also tested in practice on the Cargolifter CL75 AirCrane. CL160 was to > be anchored above the loading area to pick up cargo and then pick up > the payload by means of a built-in load frame. When setting down the > load, it was intended to pick up ballast water from tankers on the > ground to compensate for the weight loss. A ballast water recovery > system was also reportedly planned. In the end, however, there were no > more than basic technical ideas for solving the problem.[1] > > > Translated with [www.DeepL.com/Translator](http://www.DeepL.com/Translator) (free version) > > > ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 3 years ago. [Improve this question](/posts/166330/edit) How would a civilization adapt to a typical video game protagonist? People who always seemed to win any fight in front of them, but where there was only one of them, or a small team? Background. In my book, there's a historic conflict between two races of people. Both, like humans, increase in technology over time, but one side has a unique advantage. They birth a protagonist whenever there's a conflict. Whenever one dies a new one appears fully grown soon after. This protagonist would have several abilities. 1. They consistently win fights, and grow more deadly the more they slay. Armies or individually deadly warriors don't stop them. They get stronger, faster, more durable, and gain unique abilities that let them kill more people. 2. They can be slowed, but not stopped by environmental conditions and problems. They always seem to find a way out. 3. Technology and animals sent against them tend to be co-opted or taken over. 4. There is always either one, or a team of up to six of them working together in the same area. They never split up. A difficult foe to face. The protagonists are meant to be like storms, beings that you avoid or weather, not kill, and so socially people would have to adapt to them. So, how would a rival civilization best handle such a being? How would technology and population grow when your enemy could send a single person or small group against you to wipe out any group? I can imagine how you might use such a protagonist- send them against populated enemy cities or armies and have an army behind them to mop up survivors- but I am not sure how you would effectively handle such a being as a civilization and keep growing and expanding and developing technology when your hubs got killed whenever they wandered in. Props for answers at a few different technology levels (e.g. stone age, medieval, modern) since this is a over several thousand year story. Trying to find clever ways to kill them is not the point of the prompt, any more than at the moment we can do much to kill hurricanes. Edit. Extra info. Breeding is an option, though the chosen tribe tends to protect their sacred bloodlines, and they don't know exactly how inheritance of the power works. The protagonist can kill anyone, and so turning them is an option, and any internal power struggles in the protagonist civilization will often revolve around turning the protagonist. The protagonist isn't inherently any smarter or wiser than an average gamer. [Answer] Avoid Them Human history has typically revolved around either killing people or creatures that are considered to pose a threat to them or avoiding a fight they can't reasonably win. Society "works" because people feel safe that other people around them will not unexpectedly resort to violence for fear of capital punishment or reprisal. If you are predestined to win any physical confrontation there is no reason not to always resort to violence and there is nothing anyone can do to stop you. Unkillable "protagonists" that only "spawn" in a particular group of people, cannot be stopped, trapped, or slowed, only get stronger as they fight, and cannot be negotiated with would definitely pose a threat to everyone else around them. They don't even have to be outright warlike, the "protagonist tribe" can just demand tribute from everyone else using gunboat diplomacy and if they don't comply said tribe will sic their unkillable terminator protagonist on them. This isn't even X-Men where you have a subgroup of people with supernatural abilities that can occur in any group. This isn't even Attack on Titan, but it is pretty close with a set number of less than ten super-powered individuals tied to a particular ethnic group. However the titan shifters in Attack on Titan aren't as much of a threat because a) they aren't invincible, they can lose fights easily against one of their own or someone using unconventional tactics, b) they can be tricked, trapped, or sealed away, and c) the downsides with titan powers are bad enough that the average member of said ethnic group doesn't want titans running around anyway. Fate manipulation like you're suggesting means they are essentially impossible to fight and there is nothing to stop them from being monsters. Normal heroes usually aren't seen as a threat by the common person because a) they are treated within the narrative and universe as unusually skilled individuals that gained their abilities through hard work, divine intervention, or fate rather than being tied to a particular group b) they are mortal, fallible, and can lose, even Hercules died eventually and Kryptonians always have Kryptonite. They aren't "protagonists" but merely individuals with extraordinary abilities, and aren't at the same level of threat. That's another big question. Do the "protagonists'" "protagonism" powers work on their own people? Because if that's the case there is nothing to stop them from overthrowing the existing government with physical force and ruling as unkillable god-kings because they can never lose in a physical confrontation. Assassins and underhanded tactics can't even get rid of them. Think having typical Dungeons and Dragons gamer protagonist murderhoboes as autocrats. Bad. The best way to deal with such a society is to be wherever they aren't. Nomadic tendencies would become common as a way to pick up and leave whenever the "protagonist tribe" are near. The "protagonist tribe" would monopolize the best farming lands and the lands for resources, leaving other peoples with suboptimal places to live because better there than constantly under "protagonist" threat. Any sign of a "protagonist" would be a good reason to pick up and leave, hopefully before they see you. Advanced technology would be hard to make since nomadic lifestyles don't lend one's self to heavy industry. At best you might get something like some of the northern Asian steppe peoples or some North American Native American groups (flint mines) where there are hidden areas where the protagonists can't get to that make weapons and tools for the rest of the society. The best way to fight the "protagonist tribe" would be guerilla attacks on non-"protagonist" members. And...and I hate that I'm even saying this...it's highly likely that non-"protagonist" peoples would fight back by trying to genocide all non-"protagonist" members of the "protagonist" tribe. If "protagonists" can't be killed, slowed down, sealed away, or negotiated with, but they are tied to a particular people, then genociding that group of people and making them extinct is one of the few practical solutions people can implement to the problem. However, if "whenever one dies a new one appears fully grown soon after" that probably wouldn't work. But it raises the question as to why your "protagonists" are tied to that group in the first place if they aren't born in it. Alternatively, if there is any intermarriage between the two groups, the boundaries between them would rapidly become blurred. "Protagonists" would no longer solely arise within the "protagonist tribe", they could pop up anywhere because anyone has ancestry of the "protagonist tribe" within them. It doesn't even matter if there is a particular "protagonism gene" that allows protagonists to be born, because before modern genetics all people will be able to figure out is that protagonists tend to be born in some families more than others. Indeed if your story takes place over thousands of years it is possible that "protagonism" genes could be spread all over the world and their origins lost. EDIT: The more I think about this the more I think this issue is literally a more extreme version of the metaplot of Attack on Titan, > > complete with the breeding issue, ties to a particular ethnic group, other groups without a superpowered bloodline controlling the nine superpowered individuals through propaganda and threats on their (non-super) family's life, dubious methods of inheritance that no one really understands, attempted genocide of the superpowered tribe, and conflict between the superpowered god-kings over control of the non-super members of their tribe (Great Titan War). Look at that for potential avenues of conflict. > > > The biggest issue is going to be the "protagonists" are always connected to that particular group of humans, which is going to inherently turn the narrative into an "us versus them" story. There's no "convince them to side with you" like Superman or "get protagonists of your own to fight fire with fire". While the Moses situation is possible and it's almost impossible for them to reach the heights of dogmatically xenophobia seen in the Pak Protectors, they have a very strong pressure to always value the lives of their tribe over non-tribe peoples. About the only peaceful solution would be "marrying in" so everyone is tied to the super bloodline. [Answer] Psychological Warfare You see, even protagonists aren't immune to losing - you just have to be sneaky about it. By employing psychological warfare, you can have the Hero believe he's winning or has won, and in actuality, he isn't winning at all. For instance, you can prop up a figurehead as the 'Dark Lord of Evil' which can only be vanquished by the 'Legendary Hero of Good' and whip up a propaganda-esque legend that says once the 'Legendary Hero of Good' defeats the 'Dark Lord of Evil', all war can come to an end and peace can be ensured between the two nations. Thus, once the Hero kills your figurehead, the Hero will follow the rest of your 'prophecy' and ensure that war between your countries stop. Or, in the event you feel like really messing with the Hero, get him to change sides. This would need to be some kind of a false flag operation - for instance, leak some intel about a 'top secret military base' to the enemy commander who helps the Hero, and when the Hero goes to investigate and slaughters them all, it turns out that it was just a harmless lab of scientists and politicians working to make the world better. Lather on the guilt to the Hero, hire some philosophers to start chipping away at his moral outlook, and see if you can convince him to be the Hero who starts off working for the villains, but switches sides. (Do note that if he finds out you've tricked him, you're screwed and nothing can save you.) [Answer] [Kiting](https://en.wikipedia.org/wiki/Glossary_of_video_game_terms#kiting) may work The undefeatable characters do not seem to have any other purpose than fighting. So the world has no other choice but to oblige. Send a continuous stream of hostilities against them, just make sure they never figure out the real source of them. Draw them away from population centers. They can't be defeated, but they can be slowed. So give them a task to do. And another task, and another... [Answer] SHRUG AND LIVE WITH IT It is just one man or a small team. How many people can they manage to kill in fights? (It sounds from your description that they don't use weapons of mass destruction). If they kill 100 people every day, it comes to 36,500 people a year. That's only a little more than annual gun-related deaths in the US (33,636 deaths in 2013), and exactly NO steps are taken to reduce gun deaths, even though it would be far simpler than stopping your superkillers. We shrug and accept that as a small price for the right to bear arms. More than 32,500 people are killed in motor vehicle accidents every year in the US alone. We shrug and accept that as a small price for being able to take our cars everywhere. Cigarette smoking is responsible for more than 480,000 deaths per year in the US, including more than 41,000 deaths resulting from secondhand smoke exposure. This is about one in five deaths annually, or 1,300 deaths every day. We shrug and accept that as a small price for being able to have a smoke, though it could easily be remedied by a ban. Given that we just shrug and accept comparable or far higher death counts from situations that we easily could do something about, why make major efforts against killers that can't be stopped, anyway? Yes, I know that massive amounts of mney and manpower are used to limit death by terrorism, though only 225 people in the US were killed from terrorist attacks in the 15 years following 9/11 (roughly evenly divided between right wing and extremist islamist attacks) - but that is because that sort of terrorism is fairly new. As I understand it, in your world the superkillers have been around for generations, similar gun violence, car accidents, and smoking. We learn to shrug and live with old, familiar dangers. [Answer] # Pleasure Dome You need to take a lot of pages from [Evil Overlord List](https://tvtropes.org/pmwiki/pmwiki.php/Main/EvilOverlordList) and work up from there. Never murder villages, because one child WILL somehow survive and swear revenge. Never use magic powered by sacrificing orphans, because friend of one of the sacrifices will swear revenge, or protagonists who had no real personal issue with you will find it a reason to kill you at any cost. Never gloat. Never give "protagonists" personal reason to go after you. First you must be a [villain with very good publicity](https://tvtropes.org/pmwiki/pmwiki.php/Main/VillainWithGoodPublicity), that sets the stage for second phase. You said they have support of civilization they were born to, but do they? Said civilization wants to use them for it's own goals no matter what they want, this is your chance to subvert them: find out what THEY want and give it to them. If you made sure that "protagonists" don't have strong personal or moral reasons to oppose you, then you can start subverting their desire to undergo arduous tasks. [Wine, women and song](https://en.wikipedia.org/wiki/Wine,_women_and_song), sex, drugs and rock'n'roll, [crack or boardgames](https://tvtropes.org/pmwiki/pmwiki.php/Main/CrackIsCheaper), something will erode their will to fight, you just need to find out what and drown them in it. Heck, you are comparing them to average gamers, so setting up a small council of clerks, preferably posed as independent, counting their "achievements" (just 9428 more rats for [Piper of Hamelin](https://en.wikipedia.org/wiki/Pied_Piper_of_Hamelin) badge!) would be well enough, you can combine it with appeal to vanity with bardic songs or reality TV based on their "achievements" (extensive bard corps or streaming depending on tech level). Create a "hero" ranking for something superficially important and let them indulge the irrelevant. Not everyone will give up their noble goals for life of opulence, but many will. Assuming they had noble goals in the first place, and weren't just after selfish goals of fame and fortune entire time. If they were, give them that, cater to their desires: give rogue/thief a luxurious life he always dreamt of, make fighter a figurehead marshal to satiate his thirst for glory, provide mage with ingredients and assistants and let them delve into magical research, promote bard into famous pop singer. Sure it'll cost a lot, but those people are a major threat and who knows, perhaps you can somehow make money off of them. Even better, perhaps you can make them fight for you to defend their new way of life. # Sidequests [Oh no! Poor elderly widow displaced her last mite!](https://en.wikipedia.org/wiki/Lesson_of_the_widow%27s_mite) Who could possibly help her? Can be combined with Reality TV from previous suggestion: what kind of hero WOULDN'T help? Enough people think that Reality TV and wrestling are real so you won't have to fear for public shattering illusion by figuring out that widow was in fact an actor in no distress whatsoever. If heroes figure it out, it doesn't matter anyway, they don't want to disappoint their fans, now do they? Well, if they do, perhaps you can turn ALL civilizations against heroes? Perhaps they'll be too busy to focus just on your country, perhaps this will spawn new heroes to oppose fallen ones keeping both groups hero parties off your back for a while, pull some strings to even up the fights and make it last. Exploit the fact that real, systemic social change isn't very personal and distract heroes with personal quests. If you go reality TV route, be careful to manage their image and issues they tackle, lest you accidentally give them platform and following large enough to enact significant changes, you don't want any of them getting elected, now do you? That being said, perhaps you can convince them of flaws of their homeland that need to be addressed and send them back so they can use their [newfound fame to interfere with internal affairs to your benefit](https://en.wikipedia.org/wiki/Useful_idiot). Even if that fails and they rally back against you, according to your phrasing main danger lies in their uncanny combat prowess, will they be just as uncannily effective as political leaders? If not, that's still a win for you. [Answer] The clear answer is you make them King. Or your oligarchs. The situation as described can only be explained by the individual or individuals being specially favored by the gods (if your society uses religious explanations for real world phenomena) or has perfect knowledge of the future / the ability to move forward and backward in time (if your society uses high concept sci fi explanations for real world phenomena). Once you have proven to yourselves that you cannot beat them, the logical course of action is to make their abilities an asset for yourselves. The most straightforward way I can see to do that is to enlist them to rule. [Answer] ## Be the Good Guys Charity, compassion, and social well-being are the cornerstone of your society. If someone is hungry, they're fed. If they lack shelter, they're clothed. Be generous with your neighbors and welcoming to strangers. Your justice system is fair and merciful, and your government is equitable and responsible to its people's needs. Likewise on an international level--build consensus, find the win-win solutions, encourage trade and sharing of ideas and knowledge. And whatever you do, do not start a conflict with the Protagonists' people. You don't need to roll over at any sign of aggression, but always work to deescalate and seek peaceful, diplomatic solutions. And if an armed conflict does start, your armed forces consist of farmers defending their homes and plucky youths with their fathers' swords. Protagonists always want to be the Good Guys. If they're sent into your country and find it full of friendly, helpful people who are desperately defending themselves against a horrible invasion, they'll be taking up arms against their own military in no time. (If possible, also arrange to have suitable Love Interests in the area to convince the Protagonist to stay in your country after the war ends. Bonus points if you land your own branch of the Protagonist bloodline as a result.) [Answer] I like to think of it as a video game problem that needs a video game solution. They are not completely unkillable, but the are hard to kill and when you kill them, they will respawn a few moments later. So, where do they respawn? Do they have some base that can be blocked? For example if they always respawn in the same room of the same house, you can tear down the house or move a giant rock into that room, so they can't respawn anymore. Do they need some device to respawn? Then break the "respawninator" or cut off the power or material supply. Do they store their mind somewhere when they die? Then hack the server and corrupt the mind backup. Is your world a simulation? Then use cheat codes. When you hinder them from respawning, you only need to kill them once to get rid of them. [Answer] Skull Island Inveigle, trick, or hoodwink the protagonist into a quest that culminates in a one-way quest to reach the famed island of super monsters. Or simply drug the protagonist and drop them there. It really doesn't matter if there really are giant monsters there - the protagonist is a worse monster anyway. If Skull Island is too hard, then convince the supers to fight each other with broadswords - only the last immortal can with [The Prize](https://en.wikipedia.org/wiki/Highlander_(film)). Of course, since new supers appear after every conflict, nobody can win The Prize. [Answer] If opponent is about as powerful AND has these protagonists, you obviously have no chance to win, so the answer assumes a MUCH weaker opponent, except for these superhumans. Think 300 vs full Persian army; except those 300 are attacking and get reborn if they die. Now, as long as you are defending, you can have heavier weapons that with mop up anything protagonist can come up with. So, simply just defend and prevent protagonist from ever getting close enough to inflict damage. For a modern example, use simple DMZ with automatic machine guns - like the one in Korea. Yeah, protagonists can keep coming, but so what, the only cost is some ammo = not expensive. On the other hand, using a tank/plane is NOT free for protagonist. Same basic principle is easily extended to any technological level. Even stone-age people could still build stone heaps and throw rocks. Add some fires to illuminate surroundings during night, even in storm, and you are mostly fine. Sure, this is not a perfect solution, if you have a huge country to defend, all these walls are expensive and impractical. But you might have a castle to defend important people while peasants might die at the hands of these assassins. This isn't a great cost, just replace them with fresh peasants which are also in nearly endless supply. [Answer] Scorched Earth Destroy all the plants, animals and salt the earth wherever they appear. If they are players, they'll stop logging in when it's not fun. [Answer] Coerce the protagonist. They could take possession of something or someone the protagonist cares about enough to respect their demands. Assuming that, like for most of the humans living in a society, something should fit in that description. ]
[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. This question already has answers here: [Feasibility of a Synthetic Buoyancy Bladder, Used in the Air](/questions/61044/feasibility-of-a-synthetic-buoyancy-bladder-used-in-the-air) (4 answers) Closed 6 years ago. I was generally considering the idea of a flying species that uses lighter than air (LTA) gas to help provide lift, allowing it to have a larger mass than flying species can usually attend. I used the concept in my suggestion for justifying a [phoenix](https://worldbuilding.stackexchange.com/questions/28458/anatomically-correct-phoenix/86981#86981). Is there an evolutionary reason why this is unlikely to evolve naturally, or would prove disadvantageous? If I had a world where non-explosive LTA gas was more common is it likely that use of it to assist with flight would be common? [Answer] Your main problem with lighter than air gasses is that the lift provided by gas is very small compared to the enclosed volume. For an earthlike atmosphere you have an average density of air at sea level: $$\rho\_{air} = 1.292 kg/m³$$ If you take your average human being, your density is somewhat a lot more than that. If you go into a swimming pool, stretch out fully and lay yourself in the water you will most likely barely stay afloat. That is because on average, the human body has a density slightly less than that of water: $$\rho\_{human} \approx 985 kg/m³ \approx 762\\rho\_{air} $$ So your average human is 762 times more dense then air. (Hence we firmly stand on the ground). Even if you take most avian species of earth, your average density will be several hundred times more than that of air. Meaning without them flapping and spreading their wings, they would plummet to the ground just like yourself. If your animal is to float by itself without any additional lift provided by wings, then your animal as a whole must have an average density of less than the air at sea level. The maximum lift you could achieve - theoretically - would be to enclose a total vacuum within a solid body. Then your lift would be $1.292kg$ for each $m³$ of air you displace - at sea level. We have yet to find any substance that can enclose that space and not exceed the weight limit without being crushed by the atmospheric pressure. Thus we use lighter than air gasses which exert the same pressure but have a much lighter density. The best candidates for that are Hydrogen $\rho\_H = 0.090 kg/m³$ and Helium $\rho\_{He} = 0.178 kg/m³$. They acutally reduce your maximum lift compared to a complete vacuum but don't require your containing structure to be as sturdy, thus your maximum lift will be about 8-16% less than with a vacuum. Hydrogen, while readily available, obviously has the major disadvantage of being highly combustible when mixed with Oxygen. Helium on the other hand is rather rare compared to Hydrogen. Still if we assume we are using Helium, your maximum lift will be: $1.292kg/m³ - 0.178kg/m³ = 1.114 kg/m³$ The most efficient body to enclose any kind of volume is a sphere. It has the highest volume content for the lowest surface area. The volume of a sphere is calculated by $V\_{sphere} = \frac{4}{3} \pi r³$ while the surface is $A = 4 \pi r²$. The maximum mass for skin, organs, muscles etc. can thus only be $M = (\rho\_{air} - \rho\_{gas}) \ V$. The mass of the creature is however also the surface area of the creature times its skin thickness times the skin density (wihch must also contain all organs etc). If we assume a human like density creature $M = \rho\_{creature} \* A \* r\_{creature}$. If we bring both together: $$ (\rho\_{air} - \rho\_{gas}) \* V = \rho\_{creature} \* A \* r\_{creature} $$ Now since $\rho\_{air} - \rho\_{gas} \approx \frac{1}{700} \rho\_{creature}$: $$ \frac{1}{700} \* \frac{4}{3} \pi r³ \approx 4 \pi r² \* r\_{creature} $$ or shortened: $$ r\_{creature} \approx \frac{r}{2100} $$ Thus the creature's thickness would only be about $\frac{1}{2100}$th of the total volume enclosed... or for a creature with $2 m$ diameter, its skin could only (at best) have an average thickness of $0.5mm$ if it has the average density of human flesh. It would only get a reasonable thickness to withstand the elements if you make the creature have a 100 m radius - larger than the airship Hindenburg and even then, the creature on average would only be 5 cm thick (which is about the thickness of a slender human arm)... and it would still look like a balloon. This doesn't sound very feasible, considering the amount of blood needing to be pumped, the amount of food needed to digest for such a huge body etc. The only possibility for a sturdy enough skin to survive the elements and have reasonable space left for adequately sized organs would be a much denser atmosphere that can lift more mass for an equal volume. [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. Most fish have swim bladders that allow them to control their bouyancy so they can sink without losing energy swimming > > The swim bladder normally consists of two gas-filled sacs located in the dorsal portion of the fish, although in a few primitive species, there is only a single sac. It has flexible walls that contract or expand according to the ambient pressure. The walls of the bladder contain very few blood vessels and are lined with guanine crystals, which make them impermeable to gases. By adjusting the gas pressurising organ using the gas gland or oval window the fish can obtain neutral buoyancy and ascend and descend to a large range of depths. Due to the dorsal position it gives the fish lateral stability. > > > [![enter image description here](https://i.stack.imgur.com/rkkFW.png)](https://i.stack.imgur.com/rkkFW.png) Advantage: * This animal can actually float like a balloon so it doesn't waste a lot of energy compared to other animals like birds Disadvantages: * While a fish can find light air inside water, this animal should almost float forever since they're in the atmosphere (the top), or a pretty long time until they find some gas locations. * As a zeppeling, this animal would need a massive air bag to float, this means this animal would be way less maneuverable compared to a winged animal, being an easy prey for flying predators. So your animal would be almost a living balloon rather than a sentient lifeform, something like an air jellyfish. It can probably develope toxins or defensive traits to help it survive, but it would be too easy to catch. [![enter image description here](https://i.stack.imgur.com/HLCtH.jpg)](https://i.stack.imgur.com/HLCtH.jpg) [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. A lot of answers are cautioning against using hydrogen or methane because of the explosive properties of those gasses - but in reality, there wouldn't be much danger. Those gasses are dangerous around humans, but that's because humans live in a terrifying danger zone. We use fire to prepare food, use lightning to power tools, and surround ourselves with objects and spaces that are seem designed to create dangerous static charge (wool socks and synthetic carpets in a dry house? Seriously?). Most creatures avoid all those things out of fear. Sure, lightning strikes might be a problem, but then again, it doesn't matter if you're filled with hydrogen or not, really. Apart from that, hydrogen is fairly safe, as long as it is contained. [Producing hydrogen](https://en.wikipedia.org/wiki/Hydrogen_production) is possible, probably through "fermentative hydrogen production" to make [biohydrogen](https://en.wikipedia.org/wiki/Biohydrogen), or biologically produced hydrogen. I think it's entirely possible for a flying creature to use hydrogen to maintain flight. Just... don't light a match if one is descending. [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. There are a couple reasons I can think of that would discourage, but not altogether prevent, the evolution of such fauna: # Flammability Gases such as [methane](https://en.wikipedia.org/wiki/Lifting_gas#Methane) and [hydrogen](https://en.wikipedia.org/wiki/Lifting_gas#Hydrogen) would fall under this category. While both could be produced organically/with water and used to provide lift (assuming an atmosphere like Earth's), it would take rather large quantities to actually be of use for flight, at which point the risk of [combusting](https://en.wikipedia.org/wiki/Hindenburg_disaster) could easily result in deaths of members of the species. If they traveled in groups, one accidentally exploding could kill off the entire group in an explosive chain reaction. # Energy Demands Sufficiently [hot air](https://en.wikipedia.org/wiki/Lifting_gas#Hot_air) or [steam/water vapor](https://en.wikipedia.org/wiki/Lifting_gas#Steam_.2F_water_vapor) is a safer method to produce lift, but likely not nearly enough to serve as the primary means of flight, more likely just an aid. Furthermore, the caloric requirement for this species to maintain their means/supplement to flight would be much greater than another species of comparable mass, or else flight would only be feasible to those members of the species with a great enough food supply to keep these gases heated. The undernourished members would be forced to take their chances on the ground. # Rare/Inorganic Gases Another option could be noble gases like [helium](https://en.wikipedia.org/wiki/Lifting_gas#Helium) or [neon](https://en.wikipedia.org/wiki/Lifting_gas#Neon), but the latter is fairly heavy among lighter-than-air gases, and both are comparatively rare on Earth. If your world had these gases in abundant supply somewhere, like from underground vents, and your species had the capability of consuming and storing these gases long term, this solution could be possible. Of further note is that the young of this species would begin their lives flightless, and would have to consume these gases to gain their flight capabilities. # Anatomical Structure Finally, I presume this species would look very bulbous from sac-like structures large enough to offset their weight. The skin/membrane that contains the gas would have to be strong enough to withstand breaches from incidental contact with pointed objects (e.g. tree branches, coarse rocks). I exclude teeth from this as most standard animals bitten a large predator probably wouldn't survive the encounter, either, so this flight-capable species would need to adapt some sort of escape mechanism to prevent this sort of thing from-- wait... [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. There are two major reasons for it to be complicated rather than plainly impossible. * Although it's moderately easy to use a volume of gas lighter than the environing medium for animals that live underwater because gases are lighter than water, it becomes a lot trickier when the medium is also made of gases. You need a gas that is not only less dense than the average density of the medium, but also that it's denser enough to carry the solid parts of your animal. Indeed, the difference in density between H2 and H20 is pretty significant while the difference between two gases will be less noticeable. Therefore, you'll need the lightest gas possible or close to it and so much of it that it's enough to make the whole body to float. Since your animal can't use the ambiant gas cocktail for obvious reasons, it must be a - way - lighter gas, that it will be your animal's responsibility to produce. That may be more or less difficult, but the choice is already restrained by density so it has to be a relatively easy to synthetize one among the lightest. Another option is void, which is lighter than anything else, but it requires a strong and rigid container or the outer pressure will crush your lifeform. That stuff doesn't come as light so it might be counterproductive. * Even after the issues described above are solved, you basically end up with a baloon. An animal that floats in the air. While birds have great and precise control over their three dimensional speed and direction thanks to their wings that they can move in the way they want and orient accordinglingly to their needs, your animal won't have many option : producing or releasing gas and eventually directing the release in some particular direction, that's all. That makes your lifeform something like a plant or a jellyfish : something that's carried away and reacts by chemical/electrical reaction instead of instinct or choice. That may be possible, but not that fun. All things considered, that stuff applies to Earth, but you can decide that the gas cocktail in your atmosphere is heavy, therefore easing the conditions so that your idea is easier in your world that it would be on Earth - the reason why it only exists underwater on Earth. My conclusion is that you can't apply that idea to a complex lifeform without either introducing a heavy atmosphere or handwaving some stuff. [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. One thing you need to bear in mind is [Graham's Law](https://en.wikipedia.org/wiki/Graham's_law): the rates of diffusion of gases are inversely proportional to the square root of their masses. In other words, the lighter a gas is, the more likely it is to leak out of whatever container it's in. This means, you can't just collect the gas once and expect it to last the rest of the organism's life; it has to continuously collect the gas throughout its lifetime, and the lighter the gas, the more it leaks, and the more of it that needs to be collected. Also, consider that if the gas is stored within the body, it carries the risk of reacting with the organism's body, possibly acting as a carcinogen. Alternately, if it is stored outside the body, it is effectively a giant blister, just like bubble wrap. Neither is a safe alternative, especially if the gas is flammable. Lastly, air is a mixture of all available gas. If an LTA gas is commonly available, it means that the density of air is also lower. [Answer] If a flying species wanted to use a [lifting gas](https://en.wikipedia.org/wiki/Lifting_gas) as part of its biology, a major problem would be finding a source that is accessible on the surface. After all, being 'lighter than air' any free H, He, Ne etc. are prone to drifting upwards and to [atmospheric escape](https://en.wikipedia.org/wiki/Atmospheric_escape). Consider the various lifting gases and why they'd be impractical: Noble gases are found trapped underground, in quantities too minute to support evolution by nearby creatures into using them. Methane could be created as organic by-product but is flammable. Even if the creature somehow developed a fireproof coating for its 'floating organ', it would still have to contend with [explosion due to static electricity](http://www.trconsultinggroup.com/safety/sep2002.html). Well, impervious fireproof materials would also be much heavier than normal organic matter and get trapped in a cycle of needing more volume of methane which needs more heavy material to cover it! Steam may be easy to generate in most regions, but it takes a lot of energy to turn water into steam. Rising up and then encountering a cold squall would lead to condensation ending in a long fall. Again, having to evolve a burn proof, insulating (to protect other organs), impervious membrane will be a tough challenge for any would-be steampunk species. As for vacuum - the pressure differential will crush anything not sufficiently thick. A single puncture would be disastrous as well - more so than other options where the enclosing layer might have time to heal up. Energy and food requirements would be prohibitive as well: The reason why a flying species wants lift in some form (whether from 'lighter than air' gas or other sources) is to reduce energy expenditure to maintain altitude. Even if it somehow braved the odds, or had help from intelligent design (whether gods or genetic engineering) to have a 'floating organ'; the effort to maintain its condition would far surpass the simple expedient of using lightweight structures with large surface area, aka 'wings'. The massive amount of extra weight and complexity of such an organ, would also necessitate much greater food intake - which won't be found in the atmosphere, so the creature has to come down near the surface for its food anyway. This negates the only positive factor of floating over flying, which is greater efficiency in maintaining the same high altitude. Edit: Realized later that my answer draws a lot from the same 'lifting gas' entry as MSet's existing one, but I'll keep the overlap section as some things as stated a bit differently. [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. One useful alternative to lighter than air gases would be to act as a solar balloon: <https://en.wikipedia.org/wiki/Solar_balloon> A Solar balloon is black and absorbs sunlight, so the air inside it gets hot, so it becomes a hot air balloon that doesn't need a burner. The downside is that it only works during the day. You also get a lot less lift than hydrogen would give you, but without the technical problems that hydrogen would give you, like escaping and being difficult to replace. [Answer] This question asks for hard science. All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. The speculative nonfiction book [The Flight of Dragons](https://en.wikipedia.org/wiki/The_Flight_of_Dragons_(book)) is entirely about this very topic. Hard to find nowadays, but well worth the read even if you don't agree with the thesis. While positing that dragons flew by producing hydrogen in a sort of honeycomb of sacs (and that firebreathing was a method of burning off excess hydrogen in a controlled fashion to reduce the risk of sudden explosions), the author identifies numerous drawbacks to this type of biology, chief among them: * In order to be light enough to fly, they'd have to be fairly weak in terms of muscles and skeleton, and easily punctured by any sharp object. * Being thus vulnerable, they would tend to require caves or other sturdy lairs, the competition for which would make it almost impossible for them to ever be very numerous. * Young dragons wouldn't even be able to fly until they reached a size where the volume of the sacs would be enough to lift the rest of them off the ground. In short, while a LTA flying animal would be fearsome due to its size if nothing else, it would probably also be fairly fragile in both a literal and ecological sense. ]
[Question] [ In countless science fiction series, mainly the more popular ones, almost all of the aliens appear humanoid, that is bipedal with 2 arms and two legs. Is it a bad idea to include this in worldbuilding? Is it just a lazy excuse, a way of humanizing the alien or is there a good reason for an alien to be humanoid? [Answer] ## It is not a bad thing. The humanoid form has adaptions which are flexible, capable, and robust, enabling said organism to interact more or less successfully in a number of environments. It is not unlikely that it will prove to exist on multiple inhabited worlds in real life. This does not mean that there will not be non-humanoid life forms either. Just look at the variety our world has managed to produce. ## Conceptual difficulties On the other hand, it is fairly difficult to truly put yourself in another's perspective, let alone a truly alien perspective. After all, if a human can conceive it, is it an alien perspective anymore? One possible explanation for the phenomena of anthropomorphic aliens, is that it is easier (and in some cases more believable to an audience) for aliens to be just a little bit alien. They are different enough to be "alien", yet similar enough to empathize with despite the differences. This is also not necessarily a bad thing. Many stories even include the point in the meta-plot or even plot of the storyline as to why so many aliens are humanoid. ## Truly Alien As challenging as it might be to create a truly alien mindset, that has not stopped many from trying. The results range from the amusing, to the thought-provoking, to the bizarre, disturbing, and incomprehensible. Obviously, there does exist those works where someone couldn't simply be bothered to try, or other constraints (budget) didn't allow for excessive creativity. ## In the end... ... it is up to you. Pick what suits your need, make any in-plot excuses, and go for it. [Answer] Short answer: It depends. Long answer: it depends on the purpose of these aliens. Many of the popular series (Star Trek/Wars) use bipedal aliens for purely pragmatic reasons: it's much easier to apply makeup to a human actor than to make a puppet or CG model. And even when a puppet/CG is used, it's much easier for a human to animate a humanoid model than something entirely alien. We have a very thorough knowledge/intuition of how humanoids behave, which won't carry over if we make the alien a 9-legged spider. Additionally, a humanoid alien works as a form of narrative shorthand. The audience has a good sense of how a humanoid works, which means the writer gets to focus on the differences that he views as important. We don't need to consider how a Wookie might use tools or eat food or sense the world, since all of that is essentially the same as a human. All we need to care about is that Wookies are strong, furry, and speak in roars. So as a storytelling technique, I wouldn't necessarily call it lazy. It just means you're focusing on other things than the number of limbs the alien has. Now, if the nitty-gritty evolutionary biology is what you care about, there's certainly no reason a bipedal humanoid can't work. While there's a lot of bias here, humans are living proof that the design can be very successful. Having limbs dedicated to manipulation means those limbs get to specialize and become very good at manipulating things. And that dexterity is one of the keys that made us so successful. [Answer] For all we know, the only way to have human-level intelligence is to be humanoid. Notably bipedalism seems to have been pretty important in our being intelligent: * Staying on two feet requires more brain-power than on four * Delivery needed smaller heads, leading to a longer brain development (and therefore an increased ability to learn) * Hands are pretty useful if you want a technological species You can totally imagine a technological alien civilization, but you would need it to have bodies as good as ours for that purpose and find a good reason to compensate those three key points. So, it is not bad world building. It's either lazy or realistic world building, depending on how you look at it. [Answer] If you make a humanoid alien, they might be easier to relate to. However, if you want your aliens to be truly different, make them different. I do not think creating bipedal aliens is being lazy. I think if you have a six-eyed, four armed, eight-legged alien, you have to figure out how they move and what they eat or breathe or how think, and that it is more difficult to make them real. If you go with the humanoid, the reader will make certain assumptions. I think it only matters what your story is about. If is about a totally different way of being -- make them non-humanoid. [Answer] I would call it realistic, whether we are here or on another planet, all species would go through evolution. We ourselves are a product of billions of years of evolution, and we exist because we are a good combination of successful traits. So we already have a very tight limit of how aliens could look like. If we want them to be more advanced than cave men, the limits become even more drastic. They need the ability to use more complex communications, they need limbs that allow advanced interaction with their environment, they need ways to travel at least a certain distance with tolerable speeds and carry at least some weight. They need the ability to embrace their environment in detail and they need the brainpower to crate logical connections. All that would make intelligent life look very similar, even on different planets. [Answer] Richard Dawkins was once asked what alien life would look like, and he responded with something like "well, it would probably be Darwinian" A lot of things are possible via evolution. Earth only represents one outcome of evolution, and there could be many others that are hard to even wrap your mind around. # An interstellar species will probably have "arms" While the number of legs and a lot of other factors may vary, it is strongly beneficial to have at least one prehensile limb that is not used for "walking". These limbs could be anything from humanoid arms to tentacles and trunks. Intelligent life largely revolves around the use of tools; intelligence is largely a dead-weight trait if the animal doesn't have a way to make use of it, and therefore it goes hand-in-hand with a prehensile limb or two. Other than this basic soft requirement, non-humanoid forms are going to be far more likely than humanoid ones just by sheer probability. But at the same time, something bipedal with two arms is reasonably likely to emerge from a linear body plan because evolution tends to select against redundancy. However, there is no reason to assume that they would have all the same organs and body parts in the same place. For instance, the "face" could be below the arms, eyes and ears could be in wacky places, they might have multiple hearts or stomachs, they might be avian or amphibious, could have feathers, scales, fur, etc... A quadriped with a prehensile tail or extra limbs on its back could also form. You may even get an invertebrate with a radial body plan, like an octopus. Other aspects of physiology will vary based on the home planet's atmosphere and gravity, but generally will be based on the same or similar cellular structures and thus breathe oxygen and use hydrocarbons for energy because it is advantageous to be built from the most common elements in the universe. I'm no chemistry expert, but I suspect animals that inhale CO2 and exhale O2 would be unlikely or impossible because breaking down hydrocarbons and oxygen into carbon dioxide and water releases the energy they need to move and live. # Humanoid aliens are lazy and unrealistic, but practical and relatable Most of your audience won't care if your aliens are humanoid. It's a lot easier to relate to humanoids and it's easier to dress up human actors than do CGI. Non-humanoid aliens are going to be much friendlier to animation and books than movies and TV shows. [Answer] A species developing technologically is going to require some features. There are a couple traits essential to gaining a technological civilization. One is the ability to manipulate tools, You also need to be able to communicate complex and abstract concepts. Take Dolphins for instance, researchers are beginning to suspect that dolphins are far smarter than primates and theorize that they may even posses an actual language that may even be far more complex than anything we have. So why did we evolve from primates instead of cetaceans? Even if it is true that they can talk to each other they don't have hands. Also They live underwater. Living underwater means that you cant discover fire. Not having hands means you can't invent tools, or begin building complex structures. I guess my point is that if they aren't humanoid that doesn't mean they cant be sentient or have developed technology, but a sentient puddle of immobile slime or a gas cloud, or some kind of silicon based living crystal pillar isn't going to be able to build anything or go anywhere, and probably wouldn't have anything very interesting to say either. If your alien race is going to be technologically advanced you need to give them a way to communicate, and a way to manipulate objects. ]
[Question] [ This question already has answers here: [Super Spies Reality Check](/questions/51181/super-spies-reality-check) (12 answers) Closed 7 years ago. Assuming another ~80-100 years of scientific progress from our current standpoint, I believe that 'augmented humans' will be more or less a widespread phenomenon. This would take shape as any number of mixtures of technology, genetic optimization, etc. What I really want to know is, given ~100 years, could we go further: could we engineer a human or human-like creature to be stronger, more resilient, faster, etc? Basically, to what extent could we plausibly genetically engineer the perfect killing machine? I'm assuming that these modifications would need to be done early - to an embryo or to a young child - in order for them to manifest in any dramatic way. Is assuming things like increased strength, regenerative tissue, increased bone density and musculature, going too far? To clarify as requested: this is -not- an ethics question - just one of feasibility: I want to avoid going into 'it's-not-magic-because-science' territory. Further, I'm asking about relatively extreme modifications: someone who could shrug off being shot in the chest. Almost literally a monster. [Answer] The answer is easily yes. Two things are necessary for genetic engineering to be possible: 1. You have to know what to change in the genome to get the desired outcome. 2. You have to be able to change the genome in the desired way. We have already developed technology theoretically capable of editing the genome of a human embryo in any way desired. Labs across the world routinely produce transgenic mice and if they really wanted to could modify human embryos as well. With 80-100 years of progress the technology will likely become simple and cheap, driven by its usefulness in the fields of biology and medicine. The ability to use it on an adult human would require a major breakthrough of some sort, but using it to modify an embryo will likely be trivial. So the question becomes, what can we change to make our soldiers better? As an example let’s take strength, how can we make soldiers stronger? Humans evolved to be only as strong as they needed to be. That’s why when we exercise our muscles becomes stronger, and when we don’t they atrophy. It’s about efficiency. Having big muscles is nice when you get attacked by a leopard, but when it comes winter and there isn’t enough food all that muscle mass is going to kill you. Well, it turns out we know how to turn off the pathway that causes muscles to atrophy. In fact, some [humans](https://ghr.nlm.nih.gov/condition/myostatin-related-muscle-hypertrophy) already have mutations that turned this gene off and don’t appear to have any other negative side effects. The gene is called [myostatin](https://en.wikipedia.org/wiki/Myostatin) and mutants have also been observed in sheep and dogs and been created in monkeys and mice. Its deletion roughly doubles the musculature and strength of most animals. Scientists have even gone beyond myostatin and created mice that [lack myostatin and overproduce follistatin](https://www.sciencedaily.com/releases/2007/08/070828215611.htm) that leads to 4 times the normal muscle mass. What that means is that right now, in a government lab somewhere, someone could be raising a batch of super strong children. There are really no technological barriers to this, only monetary, political, and ethical. By removing the calorie-saving efficiency mechanisms evolution has given us we can better adapt soldiers to an environment where food is no longer scarce. Now, increased strength, at least to 4-fold human norms is certainly plausible, but what about your other traits? Things like regeneration or increased bone density might work out, or they might not. We got lucky with strength because evolution has somewhat intentionally crippled human muscle growth to prevent us from starving and because we happened to have an existing mutation that pointed us right to it, but right now we don’t know any way to make the body heal faster or to make bones harder to break or to make someone able to shrug off a bullet (although we could make them impervious to [pain](https://en.wikipedia.org/wiki/Congenital_insensitivity_to_pain)). With 80-100 years of additional research it’s certainly possible we discover enough about how the body performs those tasks that we can improve on them. But it’s also possible the human body might already be well-optimized for those functions and we aren’t able to improve without making sacrifices elsewhere. [Answer] Unlikely in a country like the US where the "citizen soldier" model is prevalent and veterans affairs are a constant sore issue. We actively PREVENT soldiers from using performance enhancing drugs in most cases (we actively test for anabolic steroids, unprescribed amphetamine use, etc). Plus there is a distinct lack of adoption of proper nutrition, exercise, and recovery techniques. For example, bases do not have saunas, cryotherapy chambers, or dining facilities with well stocked "healthy" food options. Barring some very elite units who might have a dietician assigned to them or some off-label drug use (amphetamines to maintain alertness during a long flight, for example) the run of the mill soldier, while evaluated for fitness at regular intervals, gets precious little support in actually enhancing performance. Professional sports teams are FAR FAR ahead of the military in this. So even if there was some sort of genetic physical enhancement program, I suspect you will see it pop up in athletics before the military, at least outside of very controlled societies like North Korea. Of course the development and research of PEDs is severely hampered by the persistent banning of any substance that might give an athlete an edge, so the concept of "fair play" will have to change dramatically in order for proper study into PEDs and enhancement programs in the first place. What would a free country do with broken or retired super soldiers? We also have a strong respect for free will and choice, could one of these child soldiers opt out of the program? What happens with their genetic enhancements? What are the long term health effects and who pays for the care? I think it would be hard for any type of enhanced human program to justify the cost compared to a drone program, aircraft carriers, guided missiles, etc. Dumping millions into children in the hope that they will be physically, mentally, and emotionally suited for the military is a relative long shot compared to hardware weapons programs. Plus no government is going to want these guys walking around out of control. Governments already have an uneasy relationship with their veterans, this would be much more unstable if the vets were super-human. Far easier to give a normal person a super-suit that is owned and controlled by the government, so that is where I think we will see more innovation. EDIT: You have clarified your question a bit. In the broader context of "will genetics make humans better" then yes, I do believe that we will have "super-soldiers" at least from our current POV in the next century. But these will be mods applied ACROSS the citizenry, not concentrated just within the military. The types of hacks useful for military performance are also often hacks helpful for everyone else. Take an ability to go without sleep, enhanced low light vision, or improved hot/cold weather tolerance. These have commercial applications so could be expected to be available to all the citizenry, not just some cloistered "army baby factory". The problem with creating, from birth, a super soldier is that the development time is just too long and the REPLACEMENT time is crippling. Unless a country can sustain a large standing army of genetic super soldiers (who are apart from the normal population) then it is likely that in a large conflict all of your elite forces will be wiped out early on and will become irreplaceable as there is an 18 year grow time so you are stuck with whoever is already in the pipeline. This is why technological solutions, like an improved armored vest instead of a grown protective carapace, are preferred. You can ramp up vest production quickly and train normal folks in their use far faster than you can grow bullet-proof soldiers. Plus the vest can get modded with the latest enhancements while the genetic soldiers will always be, literally, a generation behind the current tech. Why give humans the ability to see in the dark instead of developing a better night vision system? The genetic hacks like a simple, easily understood MHC system (the immune markers that govern self/not-self) to allow for rapid organ transplant from a common inventory would be useful for EVERYONE, not just soldiers. Same with any genetic enhancements what would allow for resistance to disease, radiation, allow for limb regrowth, etc. An area you WOULD see some military specific interest would be in genetic modifications of ADULTS. We can already do this using viruses to insert gene sequences into [cystic fibrosis patients](https://www.dovepress.com/viral-vectors-for-cystic-fibrosis-gene-therapy-what-does-the-future-ho-peer-reviewed-article-VAAT). So a new soldier, once they finish basic training, could get an "upgrade package" of gene therapy that could enhance all sorts of things, like resistance to battlefield biologic/chemical/nuclear agents, possibly ways to reduce traumatic brain injury, methods to alter the immune system to allow for compatibility to a universal blood transfusion or organ transplant system, etc. Boosting SURVIVABILITY to combat is a fairly unique military requirement that may not be necessary for non-combatants, has little disadvantage for veterans (from the perspective of the government that has to deal with them), and would allow for increased combat effectiveness for soldiers independent of their equipment. Barring a method of being able to brainwash or mind control youth to become perfect soldiers, modifying adults who have already CHOSEN to be soldiers is much more cost effective than raising soldiers from birth with the high likelihood that the majority won't be good soldiers yet can't integrate into the regular society. Even if all you want is a small cadre of elite special forces soldiers, you would need to raise a large contingent of possible subjects, most of whom would lack the mental stability, emotional toughness, and will to be a good special forces soldier, regardless of how physically gifted they are and the specificity of their upbringing. Far cheaper and easier to pull from the regular population and then enhance via gene therapy after successful training. [Answer] Yes but it is unclear if it would have a major effect. It seems fairly reasonable that in 100 years we could use genetic engineering to give the average soldier the same genetic advantages Olympic athletes have. So with extensive training you could have troops that all sprint as fast as Usain Bolt, swim as fast as Michel Phelps, and bench press like (some Olympic weight lifter) and could place in most every Olympic sport. Would this matter in combat? Not really, it much cheaper and effective to give troops equipment then to modify them. A guy in a jeep can out run Usain Bolt, a motor boat will out run Phelps and a hydraulic arms will beat any weight lifter. A man with a Kevlar vest can survive more damage then the toughest un-armored man, and instead of a multi billion dollar genetic engineering problem, each of these solutions is just a few thousand dollars and can be ramped up in a few weeks. [Answer] > > Basically, to what extent could we plausibly genetically engineer the > perfect killing machine? > > > It's pretty much not going to happen. Modifications to humans are expensive, they take decades to pay off, and most problematically, they're uncontrollable - you can't turn them on and off as you please, you can have unknown side effects, problems with their descendants inheriting, etc. Finally, there's all the ethical considerations and your people won't be happy if you conscript children. Compare this to just rolling a few Terminators off the assembly line. No fuss, no muss- easily controlled, completely disposable, mass producible in a much shorter timescale, easily upgradable, in-built wireless communication, much more effective. The only reason that humans of any kind fight wars is because we can't build robots to fight them for us. In all cases where we can (e.g. drones) we do. In the future, this won't be a case of upgrading humans- it'll be a case of upgrading robots. You would have to hit mechanical warriors pretty hard with a nerf bat to make even genetically engineered humans remotely competitive. [Answer] What makes solders dangerous? Training and the ability to rapidly process information and act on it. There are many people who are perhaps physically more dangerous, stronger, faster having martial arts training and so on than military personnel, but would not be good soldiers in the field. So if there is a need for enhancement, then improving the cognitive abilities, mental acuity, imagination and creativity may pay far more dividends than physical strength or reflexes. Soldiers and military personnel who are cognitively enhanced will be able to work the OODA (Observe, Orient, Decide, Act) loop far faster than their opponents, recognize strange or unusual situations and come up with creative solutions to problems, making them unpredictable to most opponents but still working in a disciplined and controlled way to impose their will on the enemy. As an added bonus, if these improvements are spread through the general population, then you have an economy, social system and political system which is powered by faster, "smarter" and more creative minds. A nation with that sort of home field advantage might well be much harder to deal with in the economic, political or military spheres. [Answer] Ignoring the ethics of it, raising enhanced children as soldiers isn't practical. First off you'd need a 18 year lead time for available soldiers. Good luck knowing what your military needs are almost two decades in the future. It's also a massive up front investment. Raising normal children is expensive. Enhancements and training won't be cheap either. What you get for all this time and money is someone a little stronger and slightly faster who will die just as fast as everybody else. [Answer] Think Planet of The Apes and you get an idea of super soldiers. I don't think it will happen though! If they can create such soldiers it would also mean such technology already exists on consumer channels. Otherwise you wouldn't have a health organization, genetic research facilities or yes even the dreaded black market. Then there would also be the worry what if some other nation does it first. Why it won't happen? Artificial intelligence still beats augments, I think we are slowly weaning towards this direction of modern warfare. The reason is simple $$ it's cheaper to design smart machines that can out think us. Skynet much? [Answer] No, because what you're asking... isn't the same as what you're asking. Can you add physical adaptions and enhancements to make a person dangerous? yeah, probably - it doesn't sound implausible to engineer those kinds of traits in the future. It may be possible to borrow dangerous traits from other species, to figure out how they work (and upsides and downsides) to make the traits well chosen to work together. Such a person will be dangerous indeed. Can you make this person a "killing machine"? Maybe. Certainly not a "perfect" one, a lot of interesting traits are tradeoffs - but actually you have a difference between being dangerous, and being a killer. Once you're dealing with the person, not just the body, you're dealing with psychology, with personality, and choice, and different mindsets, and so on - it's a lot, a lot trickier to try and predict traits, much less pre-select them dependently. Maybe you can select for aggressiveness, or try to guarantee sociopathy in all the subjects - and training and environment will also play a heavy role - but guarantee that every subject, or even most, will be a killing machine is not plausible. You can't guarantee that they will kill or destroy without remorse or trauma, that they won't want (and perhaps work for or rebel to get) a different life than they were intended for. Can you make this subject a "super-soldier"? Yeah, no - not the least because the traits you need for a soldier are the opposite of what you'd need for a killing machine. Your soldier must be obedient, must be loyal, must be willing to work towards your goal. Traits that would let them kill easily and without trauma would make them a danger to their own side, traits that would let them identify with their handlers and their "side" enough to be loyal would let them identify with their side's enemies (because, they are also people). Things that would prevent them from being a danger to their own side, will prevent them from being a danger to their enemies, they can be stopped or controlled by the same methods. And really, the things that make a soldier so useful, so dangerous they haven't replaced by machinery even in this advanced future? is the ability to think, to plan, to react tactically, to improvise. Good luck controlling people with that skillset, especially since they will be treated as tools for a purpose, not as people, and people generally do not react well to that kind of treatment. Raising them and training them will help somewhat with control, for a while, maybe trying to give them a reason to be loyal... but if children could be reliably shaped by into what their parents intended them to be, the world would look very differently (especially since your enhancement program gives you very little wiggleroom for people to not fall in line). They might just make a pact with the enemy's soldier-subjects and turn on both sides' worth of handlers. [Answer] Theoretically sure, but not in the way you want. What you suggest would cause a fiasco, there would be millions of people protesting raising babies for war, but there are other ways to make a supersoldier. What I suggest is a combination of the Call of Duty method and the Halo method, have a course of constant steroids, caffeine, adrenaline increases, etc; to increase production of positive military traits. This tied with an exo skeleton suit will result in a soldier that is * Stronger * Smarter * With More Endurance * Who is less susceptible to pain * Needs to sleep less ]
[Question] [ So, we are still in the context of [this question.](https://worldbuilding.stackexchange.com/questions/4241/what-would-the-real-miss-universe-pageant-be-like) The next part of making the humans intergalactic would be ... currency! Due to the fall of many currencies before, using different materials as money, we need a universal one, acceptable by all. So first of all, it cannot be: * Currency based on material. We have gold by the dozen, while Hebdonians from the Free Galaxy do not have much, yet they continue to have most of space Journalism in their hands * Time. The Gutmachtims live over 140 galactic cycles, where even cases of 200 have been observed, while humans merely live a measy 17. What might it be: * Life energy? It has been asked in a question here in this site. * Real energy? How would buying electricity work then? What are some other ideas that can be implemented in the intergalactical sense? [Answer] There's really only one option in these circumnstances: Fiat currency. If you're asking yourself, "What's 'fiat currency'?", you need only reach into your wallet -- all (or at least nearly all) of our modern nations use fiat currency, and have for at least the last half- or three-quarter-century; the US Dollar, for example, has been a fiat currency since Galactic Standard Cycle f7e99.8 (Earth Year AD 1933). So, really, what is it? Put simply, [fiat currency](http://en.wikipedia.org/wiki/Fiat_money) has value because the government (or some other ruling/powerful body) says so. Not that it sets the value of its currency, but merely that it declares that the currency is, in fact, a currency. In your world, perhaps the United Intergalactic Federation has decided that the basic unit of currency that all sentient beings within its borders can use is the "credit". Or the "umfswatch". Or whatever. When you get right down to it, currency does not on its own represent any intrinsic value. Its value lies in what you buy with it, and that in turn is determined by what the seller can buy with it after covering his/her/its expenses, which in turn are determined by the seller's supplier's costs and what the supplier can buy after that, etc. It's a step up from a barter economy because now two different farmers can buy shoes from the same cobbler after selling their eggs, versus in a barter economy the first farmer could trade his eggs for shoes, but now the cobbler has no use for the second farmer's eggs and thus refuses that trade. Using currency we avoid that hassle, but at the end of the day, when all is said and done, shoes cost 15 gorks because that's how much the cobbler needs to buy the eggs to feed his family (after paying the tanner for the leather he used to make your shoes). And that's how fiat currency works. (It's also, generally speaking at least, how commodity and other such currencies worked as well -- cocoa was a currency because you could make it into sweets that anyone could enjoy, but how much it took to buy a pair of shoes was still determined by what the cobbler, in turn, could buy with it.) [Answer] If there is a galactic currency then there is a galactic government to manage it. So, as Kromey says, fiat currency is the most obvious and sensible answer. However, there will always be races who do not want to participate in such systems. The universe is a vast and infinitely diverse place. Perhaps the concept of fiat currency is too strange for some aliens. In such cases, as it would be by default without a common government, the default is the seller chooses the currency. The barter system will reign. You want to trade with the Gutmachtims? Those long lived creatures fear death, one can complete dangerous missions for them in trade for their knowledge. The Hebdonians from the Free Galaxy need our gold for their shipyards, we want their platinum, we can trade. [Answer] Don't confuse the goods with currency. Goods are the things the people want to trade. The currency is only the mediator. It doesn't have to be a valuable thing. In fact, it shouldn't be a valuable thing, especially in intergalactic trade. Why that? Consider our situation now. For some time, there was the gold standard, which was the promise by the US bank system to trade in gold for money. This keeps currencies rather stable, i'd say. However, there is a problem: Once the money that's around surpasses the available gold, you can't hold to the promise. That's why we the gold standard was dropped (as far as I understand, and without the historical context). So, the value of the generated goods far outpass the gold value available to back up the money. If we kept to the gold standard, there would be shortage of money. You can't trade, although you have valuable stuff to sell and want to buy other valuable stuff. This problem becomes even bigger the more you scale your system up. What do you think how much value is produced in an intergalactic society? I can't imagine, but it is certainly too much to make one specific valuable thing the currency. Not even the spice is THAT valuable. [Answer] A couple of possibilities: Power Source - maybe there's an extremely rare material that's used to power FTL flight. Everyone participating in the interstellar union needs it, so it ends up with a universally accepted value. Wishes - A particularly powerful Elder Race, or a group of them, could have declare and enforce a galactic currency. You would need a reason why they want it - maybe playing with economies is their version of chess? Since they need to back it with something to encourage participation, they make it so if you acquire, say, 1 billion WishBucks that you get literally that - one wish. Think a semi-friendly genie - immortality, technology that looks impossible to us, basically you name it and you get it. [Answer] I think the answer to this problem lies in the way money was actually created. > > The year is 9000BC. You've done a hard day's work building those > pyramids and now you want to get home and eat something. The trouble > is, you have to find something on the way back home and nobody ever > wants to give you anything, you usually just have to find it. But > today you have... A Plan. You've got a big basket of fruit with > you. And your Plan works. You go up to the man who raises cows and you > ask him for a pound of beef. And of course he says no, but "aha!" you > say, "I have here some fruit. I will give you this fruit if you give > me that beef." And you get your beef and it's good. > > > And life continued such for a while. People traded things they had for things they wanted. But the problem was sometimes the person who had the thing you wanted didn't want the thing you had. And so the goldsmith comes along. > > "People! I have great news! We all value gold, do we not? Therefore > trade gold for that which you desire and never let your desire go > unsated again!" > > > That's right, the first coins have been invented. But the next problem is thievery. There's no way to prove whose gold is whose so it's easy to steal. But the city guards come to the rescue. > > "We will store your gold in the greatest locked vaults in the city, > and give you I.O.U. notes for the lot. For a small fee." > > > And thus paper money was invented. And so on and so on, more thieves, counterfeit money and ways to combat it until we have today's system.$^1$ --- The point of telling that story was this: money is actually a promise. A promise that if you take your paper to the bank, they will give you its value in gold. Technically. (It won't work in practice, I don't advise trying.) And originally, it was a promise from a banker to give back whatever it was you gave them to keep safe. So my answer is this: paper. More specifically, bits of recognizable, fraud-safe bits of paper with promises on them, promises from a Universe Bank to give back whatever they've been given for safekeeping. The Bank would also be the entity that sets the value of each type of planetary currency. It's a bit like the money we already have. --- $^1$ There's a pretty good video explanation of that on [YouTube](https://www.youtube.com/watch?v=FuHQhGqZvY0.) [Answer] Hmm, if your societies are NOT integrated, no fiat currency. From personal experience trading with other soldiers - luxuries. Popular with us was drugs (tobacco, booze, caffiene),'white gold' aka toilet paper, and staple food (exotic to the other) [Answer] Money is divisible, interchangeable, impossible to counterfeit, countable, verifiable, not subject to decay, rot, or rust, and it is rare. These are the properties of any money. * Gold. It's universally accepted here, and is likely to be elsewhere. Gold has all the properties of money. It is unlikely there will be a lopsided distribution of gold in one planet, because stars can only make so much gold during a super nova. A planet full of gold or lacking gold is not scientifically realistic. * If not gold, then perhaps another high-atomic number element, such as rubidium (which currently costs more than gold). * If not a precious metal, then perhaps a synthetic element that only high-technology societies can create, like Einsteinium. Of course they would also have to find a way to make it stable. * If these societies can transmute matter, and create gold or other elements from energy, then matter is not an option. The choice then becomes energy, information, or entropy. * Energy. All money is in essence a form of energy, as it requires energy to dig gold out of the ground, or to synthesize rare elements. So there may be a common energy storage that creatures find useful, whether barrels of oil, or Energizer batteries, or dilithium crystals. Since stars will provide nearly limitless energy and presumably all societies will be capable of solar power, energy might not be a viable currency unless there is a unique and rare storage mechanism which enables storage of vast quantities of energy and allows divisions, verification, and all the other properties of money above. * Information. Crypto-currencies. Bitcoins have all the properties of gold above, plus they allow instant transmission and low transaction and storage costs. Assuming no creature has created a quantum computer, then a galactic crypto-currency is highly likely. * Entropy. The ultimate root of all money and value is low entropy. Gasoline is valuable until it combusts. Bitcoins are valuable because the bits are arranged in a specific order. Gold is valuable because it's a high atomic number particle that requires tremendous energy to create. So, assuming a society is so advanced it has unlimited energy, can transmute matter, can create quantum calculations, then the only value left is in highly complex and creative arrangements of matter, namely art, music, literature, sculptures, etc. This is why the Primer in Diamond Age was so valuable. All housewares were disposable commodities items even to the poor, but something so exquisitely arranged and rare at a molecular level was priceless. Of course any creature could copy one of these units of currency, but the first one of its kind borne of creativity will be quite valuable and can be auctioned for other creative works produced by other creatures - since commodity items are worthless. Even [North Korea exports art for minerals and money](http://www.wsj.com/articles/SB10001424052748703906204575027400440309756). It is highly unlikely that all creatures will trust a single planet or government and accept its fiat currency. Most technologically advanced societies will be able to counterfeit such a currency anyway (as North Korea does with US dollars). [Answer] In fact, current money are not promises that you can get gold back, nor that you can buy anything. They are promises that the State will accept the coins to fulfill your taxes. This is why Counts and Lords minted their own coins during the Dark Ages: they wanted to be sure they were receiving the amount of gold they expected when getting the taxes in, so they minted coins, used them to pay their fellows for services and goods, the coins circulated because everybody trusted that the Lord will accept them back, and when it come to pay taxes, everybody used them, and the Lord accepted them. This could not work with aliens. So you have several options: 1. Find a common scarce material and transform it into a common currency count. It may be gold, platinum, iridium, uranium (in some form that avoids nuclear explosions)... something that is not easily craftable, but is easily measurable. 1a. After 1. and after confidence has been established, create a fiat currency based on that common scarce material ("This coin worths 1 gram of uranium">"This note worths 1 gram of uranium">"Some annotation on my accounting book means I owe you 1 gram of Uranium") 2. Find a pair of abundant/scarce materials and agree on an exchange rate. Maybe their platinum against our water, on exchanges 1 ton for 1 ton. 2a. After 2. and after confidence has been established and the value has stabilized, create a fiat currency based on that interchange rate ("This coin worths 1 gram of wood-equivalent platinum" etc.) [Answer] > > Due to the fall of many currencies before, using different materials as money, we need a universal one, acceptable by all. > > > Well, now the countries are bordering each other and we don't have one currency, acceptable by all. Having galactic currency is simply unfeasible. First of all, issuing own currency is power. If you control the currency, you can change the value of your debts and the debts other have by you by printing it, or otherwise manipulate its value. This is what the US are accused of by other nations, and why the Chinese are threatening to switch their reserves to EUR. Second, even if not intended, the currencies change their value. The intergalactic communication is the complete different time scala. The trade expeditions will take from hundreds to millions of years. It's completely impossible to tell what value would that currency have after so many years, and even if it will be accepted (the currency notes are changed every X years to prevent faking them). Third, the whole trade concept. The energy needed to transfer some goods from one side of the galaxy to the other is so immense, that it exceedes any possible value of that goods. So the only goods that, I foresee, will be traded on long distances is the technology and the territory (space). The trade will probably exist only on local scale (solar systems) and there will be enormous number of local values, practicably not exchangable to the other (non local) currencies. [Answer] You've established that both "time" and "materials" are too unevenly distributed to work. Rather than bringing in "energy", and the question of which form it should take or how energy is not unevenly distibuted, I'd go for what's left when you subtract time, matter and energy. Namely "space", the substrate of existence which is undeniably common to all species. Nobody needs a special flavour of space. Concretely, the currency would be bubbles of warped space. Fiction and non-fiction has established these as a method for propelling spacecraft at FTL speeds, they can be harnessed to produce energy, used as weapons, employed as shields and barriers, used to store things in, to provide extra room inside a small spaceship or perhaps even to slow or speed the passage of time for someone within the bubbles, so that short-lived species can in a sense "buy time". This also makes for a nice substitute for cryo-sleep. You can imagine that bubbles of warped space could be produced in several different ways, which plot-wise allows the species to have comparable levels of wealth, if that's what you want for your story-universe. [Answer] Energy would be the most likely. Night's Dawn, whilst a generally human "universe", uses Fuseodollars, an analogous currency to [petrocurrency](http://en.wikipedia.org/wiki/Petrocurrency), where trade was based on the availability, adjusted by the cost to transport, He-3 (helium 3), which is used in nuclear fusion (the dominant form of star-ship fuel in the story). Basically, the cost of any item would be directly proportional to the expense to transport it. However, what substances would an intergalactic currency be used for? Any commodity that could be bought in one sector of the galaxy is likely to be much easier to reproduce somewhere else rather than transport it. The only thing that could be valuable, in any sense, is intellectual property (as even raw mass can be produced from energy if need be). But as nothing of any value could be transported over those distances, there would be no value to be gained by maintaining a monopoly on the ideas or art. This would be a very different economy to what we would be familiar with: think of it like everyone has a 3D printer, and can turn starlight directly into mass. The only thing that would be really valuable in this economy would be any element heavier than iron in the periodic table. That is, only once all other resources have been exhausted, however. If this is the case, it would be likely that either Lead or Bismuth would be the most stable currencies. [Answer] Money simply facilitates trade - I'm not convinced that there is truly a need for a universal single currency. Monetary needs are different for different economies, and no single monetary policy is likely to best for every situation in the universe at all times (surely there would be some variations in development, productivity factors, financial systems, etc). If there isn't significant trade, such that there is a significant system of exchange between many people trading into and out of a currency, there might not even be any need for exchangeable currencies. Barter would be needed for the rare exchange because there is no meaningful use for the other currency. In between those two (single currency and barter) would be local exchangeable currencies. Each locality can use their own currency, with monetary policy set to the needs of their economy, and using a clearing house for instant exchange between the various currencies being traded. This takes such a negligible amount of computing capability such that real-time conversion of currency denominations has been trivial for us for decades - it certainly shouldn't pose a computational challenge for the technological abilities of a intergalactic civilization. But yes, were there a single medium of exchange, use of any physical object would entail actual transporting that substance as well as the significant price differentials between localities based on the value of that substance (presuming there is not costless instant transport through every point in the universe). Even 'energy' requires some medium to store and transport said energy no matter what form it takes. A fiat currency would be the only meaningful intergalactic currency, and then you have problems of who sets the monetary policy of the currency (policy is set very tight on the capital, but some minor galaxies suffer serious depressions because they need a loose monetary policy). Just look at the problems with the Euro - Germany wants a tight policy, Greece is absolutely desperate for devaluation. A single currency would not be at all desirable. ]
[Question] [ I want to create a universe where the visible universe is much smaller than that of our own. The idea is to create a sort of "fog of war" around every star system. In our universe, you can see pretty much every other star, even if, due to the extreme distances, you may only be able to see the "present" of those stars a few years after it happens. I want it to be such that some residents of my universe can only really see a few stars outside of their own, and maybe a few more with technology. In order to see more stars, my universe's residents would have to go expand to other stars. This is in order to create a dynamic similar to how we explore earth; areas that were before completely unknown would then be discovered and charted, and then reported back to be acted upon. I've considered: * Changing the speed of light, or the size of atoms, or some other fundamental constant — this changes so many other things about the universe as to make it completely unrecognizable. so I've ruled out this. * A viscous [luminiferous aether](https://en.wikipedia.org/wiki/Luminiferous_aether) — the idea here is that light will get redshifted extremely quickly, therefore creating the fog of war effect I want. The cloud of vision so-to-speak will be slightly nonspherical due to aether winds, but I'm fine with that. The main problem here I believe is that light would be rather slow, and I sort of want to keep it at the speed it is now (or faster) * A 4+0D aka Riemannian universe — This sort of universe has no defined speed of light, so I could make it as slow as I want it to be, and hence would allow it to redshift faster. This has the same problem is the luminiferous aether though, I ideally would not want to slow down the speed of light. It also introduces many other weird artifacts such as negative kinetic energy, which I would prefer to avoid. * A literal "fog" of war. There could be very numerous gas particles that exist everywhere, dispersing light, and generally making looking far hard. The problem is, of course, gravity. It's sort of hard to make anything not affected by gravity, since it's literally just how space is curved. I guess I could handwave a particle that isn't affected by gravity to make this work, but there's more issues with this. Because of the abundance of this particle, there would probably be a lot of interactions between it and "ordinary" matter, which would probably create a lot of new implications for chemistry. While that's interesting, I would rather just have something that doesn't completely change the way our universe operates. So, what could I even use to justify a universal "fog of war"? [Answer] Crafting an alternate universe without modifying the basic principles of our own is a bit like trying to redesign a car engine without modifying any of its components. Eventually, you're gonna have to face the necessity of making adjustments, however minute they may be, such as considering electrons with slightly more mass or something. That being said I think what you should focus on is a specific area of some galaxy rather then the entire universe. This specific region is currently witnessing the aftereffects of an extraordinarily rare cosmic event - a simultaneous supernova explosion of a thousand stars. The result is a massive interstellar cloud enshrouding your galaxy sector, producing that "fog of war" effect you're after. May seem a bit convenient, but on a cosmic timescale with nearly infinite galaxies? it's bound to happen somewhere, right? [Answer] > > A literal "fog" of war. There could be very numerous gas particles that exist everywhere, dispersing light, and generally making looking far hard. > > > That's what a nebula is. Some block more light than others, or are transparent to certain frequencies ([this answer](https://astronomy.stackexchange.com/a/43770) goes into more detail), but there exist some [dark nebulae](https://en.wikipedia.org/wiki/Dark_nebula) that are dense enough to block most visible light. Gravity does work on them, of course, but they're many light years in diameter, so they tend to stick around for a long time. [![Barnard 68 Molecular Cloud](https://i.stack.imgur.com/kVQ18.jpg)](https://i.stack.imgur.com/kVQ18.jpg) ([Image source: https://en.wikipedia.org/wiki/Barnard\_68](https://en.wikipedia.org/wiki/Barnard_68)) Parts of a nebula could collapse to form a star, which would likely clear the immediate viscinity, but if you have a number of stars inside a particularly large dark nebula, that should give you the sort of visibility issues you want. The [Great Rift](https://en.wikipedia.org/wiki/Great_Rift_(astronomy)) probably has enough room for quite a few systems. [Answer] You get the fog of war for free at interstellar distances. The existence of any system where war is possible between stars (FTL travel of any sort) automatically provides the 'fog of war' in a very real sense. When the closest star is 4 light years away, any remotely gathered information is 4 years out of date, and therefore essentially useless during a war. You need 'boots on the ground' (or at least local to the star system) to gather information, and bring it back (via FTL travel) with a useful shelf-life. The existence of a star system is no more of a surprise than the existence of a mountain range, or a city. Once you know it's there, you can expect it to stay there for the useful future, and the 'fog of war' doesn't hide those. It hides the easily changeable things, like the location/composition of defending forces, or industrial capacity. If, on the other hand, you don't have FTL travel, that fog of war becomes meaningless, because you're not going to be visiting those locations, much less fighting wars over them. (Nobody starts a war with someone when you can't even communicate with the same person more than twice in their lifetime/career, and sending soldiers would involve conscripts whos grandchildren show up with rifles.) [Answer] ## Short-lived photons I'm not sure what the effects are, but you could have all EM (or just visible light if you want?) photons dissipate after a few lightyears. As for how, unless you really need to, you can ignore the reason. You're not building a physics simulation. Unless you're a physicist and dig deep into the mechanisms, the only effects will be that long-range EM travel is cancelled, while leaving everything else the same as it is now. [Answer] In about a trillion years, the expansion of the universe may have limited the visible universe to the local cluster of galaxies. For a good summary, see [this article](https://en.wikipedia.org/wiki/Future_of_an_expanding_universe). This isn't quite what you are asking for. The local cluster of galaxies is a big region. But if they are very long lived and willing to hop between galaxies, then maybe we can replace stars with galaxies. Or you can go the other way, and set your story in the reionisation epoch, with time travel to explain how life got there. Space is very big and very empty. Dark matter is invisible rather than dark. It would take a lot of opaque stuff to fog the gap between stars, and it would collect under gravity. We live in a huge universe, but we can actually see a lot of it. I get what you are after: it would be a bit like inventing flight on a permanently cloudy planet where you never see for more than a few hundred feet. [Answer] > > This is in order to create a dynamic similar to how we explore earth; areas that were before completely unknown would then be discovered and charted, and then reported back to be acted upon > > > I'll answer the question not asked as a bit of a frame challenge. How do you recreate that dynamic when you know where all the stars are in the sky? We do know where all the stars are in the sky, where they were, and where they will be. This is a capability available in commercial software for astronomers and hobbyists. We know where those stars are in the galaxy. We can look at those stars, detect exoplanets, and extrapolate a number of parametres. But more or less, what we know from all that is if a planet maybe potentially could possibly support life. "Support life" largely means liquid water on the surface and and breathable oxygen. But if I was looking to settle, I'd like to know for instance if it's possible to sip marguaritas on the beach. To know that, you're going to need a closer look, a full survey to learn about the climate and the seasons, to map the terrain, to look for arable land, to know whether there's deadly megafauna or flora, and to analyse what pathogens colonists will be exposed to. That's a process that could take years on its own, and you can decide how likely it is that a planet will be A) actually suitable, and/or B) suitable according to the government's standards. Then it wouldn't be a bad idea to expose your colonist to that atmosphere in a safe and controlled environment in a lab on Earth so they can adapt and won't immediately fall sick and die. This is something we know happens when we go to new, unexplored places. That might take some more time. And that's how I'd recreate a sort of galactic Age of Discovery. Lone ships sent into deep space to survey promising exoplanets in full detail, that you can have report back to Earth or the nearest colony, before you can mount a full colonisation attempt. [Answer] Oort clouds. The Sol system Oort cloud is a low-density comet region. The region is cold and dark, and according to Wikipedia, no object has ever actually been seen in it, though we see comets leaving it as they approach the sun. Your star systems could all have significant oort clouds made of obscurium, a material that absorbs, scrambles, and re-emits light. If the cloud is much denser than ours, it could make looking at a distant star system impossible-- you'd know where the star is, but not anything about the planets orbiting it. Some potential features of Obscurium: 1. Strangely large electron clouds with many more possible quanta than normal, allowing each molecule to absorb more wavelengths of light in a larger area. 2. clouds of obscuria quantumly entangle with one another, absorbing and emitting light as if they were a single particle. 3. Their bonding distance is extremely large, making what appear to be cosmic clouds of obscuria gravitationally stable-- they will never condense on their own. 4. Perhaps Obscuria has some property that partially repels it from gravity fields, yet also has parts that are attracted to gravity fields. The equalization point of these two conflicting pulls happens to be 1-2 AU out from a sol-like star. Two opposing forces with an equalization point is very common in molecular bonding and life, the main difference here being you have to have an anti-gravity force. If you don't want antigravity, perhaps these particles could be extremely sensitive to electromagnetic fields, such that they're repelled from the sun (which is slightly positively charged), until that electromagnetic interaction is weakened by 1-2 AU of distance, at which point gravity keeps them in place. I think #4 is the best solution, as it achieves your goal of fog-of-war without impacting the void between stars, which would change spaceship speeds. Having them be strangely electromagnetically sensitive is a handwave, but maybe not the most impossible one. ]
[Question] [ Picture this...the sun sets over an orangish red desert, in the distance you see a town rising from three hills, a river snaking between them. The buildings rise from the hills and spread between them. Atop the highest hill sits a magnificent cathedral that rises above the rest of the city, its red stone walls reflecting the orange of the sun. I have a concept for a desert city wherein most major buildings are made of sandstone. I am unsure of the utility of sandstone for construction though and have a few questions. * How strong is sandstone, meaning how many stories tall could a sandstone building be? * Lumber is available from the river that flows through town, it is floated down-river from the nearest forest. So it is available but is pretty expensive. * Can sandstone be red or orangish-red? * How ornately can sand stone be carved? * Are there any durability concerns if it can be used? Real world examples (if available) would be appreciated in answers. [Answer] # Yes. Please do. For inspiration, you can google image search one of the most amazing places I've ever been to: [Petra](http://en.wikipedia.org/wiki/Petra). It is very complete from residences to commercial and community facilities, as well as rudimentary utilities, including a stormwater drainage system. Other answers have given you examples, so I will build off of theirs by adding my experience of Petra. It took us three full days of exploring, and while the [Bank](http://www.hargest.com/gallery3/index.php/Travel-Pics/worldpics/petra/Petra-Bank) was made famous by Indiana Jones, El Dier was incredibly complex inside. Height - Your mountain is the limit, you can build as high as the environment allows, or as deep as the material allows. Petra's highest residences were G+6 (ground +6 stories), but because it was in the sandstone mountains, the entire site, with abundant 'roads' and staircases rose about 300m from the base of the city to the higher residences - maybe more (I can't find this information online). Lumber - You can limit lumber to the functional spaces, as you like: doors, etc. In this example, lumber survived the years and served to close portals such as windows and doorways. Color - Petra is called the Rose City by some, and it is exactly the color you seem to be describing. Ornate-ness - Very. As you will see from your google-image search, the precedent that I'm discussing had very ornate carving, which held up against the elements because half the site is below ground level, and there is limited rainwater. I can't imagine how much more intricacy has been worn away by the wind. Durability - The only threat to your city is from the elements. Please protect it, since I'm now kind of falling in love with your city, from rainwater, and keep your river from washing it away. Petra has been known to exist for over 2,000 years in a relatively dry climate. If you want more elaborate utilities, sandstone is very pliable, as shown in the examples provided by other answers. Another beautiful example was the beautiful horizontal and vertical [troglodytes](http://en.wikipedia.org/wiki/Troglodyte) of Tunisia. Horizontal 'cave dwellings' are carved into the sides of (in Tunisia) sandstone, while vertical are carved down. They were occupied until about the 1960s (no source), but we helped a guy from a nearby University establish an eco-hotel out of one of them. They are between 1 and 10 stories vertically ("the mountain's the limit"), and being rock, they moderate temperatures in your desert. In fact, one of the very real troglodytes is in a town called Tataouine, whose name has been transferred to [a popular movie](http://en.wikipedia.org/wiki/Star_Wars), which filmed there several times, and took the name. [Answer] Some points for your question: 1. [Sandstone Buildings](https://www.google.com/search?q=sandstone%20building&safe=strict&espv=2&tbm=isch&tbo=u&source=univ&sa=X&ei=ZsIuVYbeH8z9yQT744GQDA&ved=0CB4QsAQ&biw=1252&bih=778&safe=high) actually exist, and are common. As you can see if you search for them, they come in a variety of colors. 2. A look at [wikipedia's Sandstone article](http://en.wikipedia.org/wiki/Sandstone), an informal source of knowledge, claims that it has been used for buildings since time immemorial. 3. [GSA.gov](http://www.gsa.gov/portal/content/112582) has a good overview of sandstone as well. Depending on the sandstone, it can be orange, red, pink, and perhaps a few other colors. 4. Sandstone can be great at weathering; that is, it is resistant to wear from rain and wind. 5. As seen [here](http://www.engineeringtoolbox.com/compression-tension-strength-d_1352.html), sandstone has a much higher compressive strength than most bricks and concrete. This means bigger buildings! 6. Sandstone is very easy to carve. Google "[sandstone lamps](https://www.google.com/search?q=sandstone%20lamp&safe=strict&espv=2&source=lnms&tbm=isch&sa=X&ei=ScYuVa6EMsSkyASsuoCQCg&ved=0CAgQ_AUoAg&biw=1252&bih=778&safe=high)" to see just how detailed they can get! [Answer] Yes ['Sandstone has been used for domestic construction and housewares since prehistoric times, and continues to be used.'](http://en.wikipedia.org/wiki/Sandstone) You can easily google multiple story buildings made out of sandstone. [Qutb Minar is the 2nd tallest minar in India and made of red sandstone](http://en.wikipedia.org/wiki/Qutb_Minar) Looking up more pictures and sandstone building, it seems sandstone is a pretty good material for building and allows for rather fancy carvings and decoration etc... (not to mention you do have different colored types of sandstone) [Answer] Its difficult to have a city wholy made from one material. Even if rich people can afford sandstone, poor people will still build shanty towns made of [adobe](http://en.wikipedia.org/wiki/Adobe) all around the walls. The richest people will import other types of stone for their palaces, or use less frequent (more expensive) types of sandstones. A realistic city will have variety, unless: a) everybody is wealthy b) sandstone is very abundant c) government enforces building regulations on using only sandstone Adobe is a mix of mud, clay and straw. Cheap and abundant materials for most peasants. Bonus points if there is a shortage of alternative materials. In Spain, poor people in the 19th-20th Century made buildings out of adobe, because they couldn't afford the more expensive materials. Whole cities made of adobe, with rich people building with normal brick, and churches being the only buildings made in stone. Adobe houses are very fresh in summer and very resistant. I am told that walls had to be very thick: at least 30 centimetres of thickness for a 1-store building. Wood is still necessary! Storied buildings will still need wooden beams for the floor. Wide roofs need thick beams for support. Poor people will build one-storied houses. The poorest will make small buildings with funny-shaped roofs to avoid using expensive wooden beams. The outer side was covered with plaster to protect from erosion. Exposed adobe will slowly trickle back into plain sand. If your roof fails, the rainwater will quickly damage the walls. Looks like sandstone doesn't have this problem. Of course, poor people are more worried about getting a floor over their heads than about long-term durability. In some cases, it might be cheaper to build a cheap and replace with a new house than to build a solid house and repair it with good materials. ]
[Question] [ In the Holy Books of a number of religions, we see the prophets of what is depicted as the true god always struggling against priests of false gods, who are often able to accomplish amazing feats. But the rival priests are all just faking it... Now imagine hugely advanced humans, with powerful [silvery machinery](http://tvtropes.org/pmwiki/pmwiki.php/Main/CrystalSpiresAndTogas), fracking spacetime itself for unobtanium, and accidentally drilling their way into what looks like Heaven. Picture it however you want: Angelic figures with wings on their backs, lots of harps, pearly gates, rivers of milk and honey and mead, [72 figs](http://www.nytimes.com/2004/08/04/opinion/martyrs-virgins-and-grapes.html), the works. How would we be able to tell whether we're dealing with [divine](http://tvtropes.org/pmwiki/pmwiki.php/Main/God) [beings](http://tvtropes.org/pmwiki/pmwiki.php/Main/CrystalDragonJesus) or simply sufficiently advanced aliens trying to co-opt our religious myths? [Answer] You can't tell. Any sufficiently advanced aliens would be able to directly control what your senses perceive. So you'd see and hear and touch and taste and feel exactly what they want you to. Therefore let's say they offer 'proof' of their divinity by doing some miracles, something physically impossible - no problem at all. They'd be indistinguishable from Descartes' [Evil Demon](http://en.wikipedia.org/wiki/Evil_demon): > > The evil demon, sometimes referred to as the evil genius, is a concept in Cartesian philosophy. In his 1641 Meditations on First Philosophy, René Descartes hypothesized the existence of an evil demon, a personification who is "as clever and deceitful as he is powerful, who has directed his entire effort to misleading me." The evil demon presents a complete illusion of an external world, including other minds, to Descartes' senses, where there is no such external world in existence. The evil genius also presents to Descartes' senses a complete illusion of his own body, including all bodily sensations, when Descartes has no body. > > > and the effect indistinguishable from that of the '[brain-in-a-jar hypothesis](http://en.wikipedia.org/wiki/Brain_in_a_vat)': > > In philosophy, the brain in a vat (alternately known as brain in a jar) is an element used in a variety of thought experiments intended to draw out certain features of our ideas of knowledge, reality, truth, mind, and meaning. It is based on an idea, common to many science fiction stories, that a mad scientist, machine, or other entity might remove a person's brain from the body, suspend it in a vat of life-sustaining liquid, and connect its neurons by wires to a supercomputer which would provide it with electrical impulses identical to those the brain normally receives. According to such stories, the computer would then be simulating reality (including appropriate responses to the brain's own output) and the person with the "disembodied" brain would continue to have perfectly normal conscious experiences without these being related to objects or events in the real world. > > > [![Brain in a jar hypothesis](https://i.stack.imgur.com/qx09x.jpg)](http://en.wikipedia.org/wiki/Brain_in_a_vat#/media/File:Braininvat.jpg) You have no way to confirm that this hasn't already happened to you. Watch out for [Agents](http://en.wikipedia.org/wiki/Agent_Smith). (See also: [Clarke's Third Law](http://en.wikipedia.org/wiki/Clarke%27s_three_laws).) [Answer] Edit: I'm seeing a lot of comments that bring up issues already addressed by the answer. Make sure you read the entire Third section and Conclusion. There is no TLDR. ## First, to define the Divine: A recognizably sapient entity that exists beyond our universe. Note that this definition has little to do with general religious thought. The reasons behind each part are as follows: 1. Recognizably sapient - while it's possible that the divine could be incomprehensible, that would prevent any useful discussion. So for the purposes of logical argument, the divine must be understandable. 2. Any being restricted to our universe - obeying all of the laws - is logically indistinguishable from sufficiently advanced technology. ## Second, to prove the Divine: Our proof follows logically from the first portion: The Divine must be able to break the core laws of physics. So for example, a Divine being should be able to violate our core physics laws - conservation of mass/energy, for example. They can add mass without energy, or remove energy/mass with no mechanism. ## Third, the issue with proof: Unfortunately, it's nearly impossible to determine if someone is actually breaking the laws of physics, or is merely doing a clever runaround. Is your god really creating energy from nothing, or are they actually exploiting a flaw in your understanding of physics to keep you from figuring out what's really going on? This means that only a civilization with a mature and rigorous understanding of all physical sciences is capable of telling the differences. But of course, it's really hard to tell if you actually have a complete understanding of physics, or if your understanding is incomplete in some way that you have yet to detect. ## Conclusion: It's logically impossible to tell. You can never be sure that you know enough physics to tell the difference, so it is literally - and appropriately - a matter of faith. ## All is not yet lost: While under this definition we can't prove something is Divine, we are offered a method to prove that something isn't Divine. If you can show the mechanism behind the angels - how they're doing what they do, the man behind the curtain - than you can be reasonably certain that you've found aliens. Although I'm sure the faithful will just tell you that the Divine works in mysterious ways. [Answer] Since this related to religion and specifically judaeo-christian mythology, I can answer with a Bible quote (Luke 6:43-45): > > 43 “For a good tree does not bear bad fruit, nor does a bad tree bear good fruit. > > > 44 For every tree is known by its own fruit. For men do not gather figs from thorns, nor do they gather grapes from a bramble bush. > > > 45 A good man out of the good treasure of his heart brings forth good; and an evil man out of the evil treasure of his heart[a] brings forth evil. For out of the abundance of the heart his mouth speaks. > > > This is actually a principle applicable outside religion as well. If the actions of the aliens/angels make it apparent that they are trying to trick you, then you will know. If this does not happen, you are losing nothing by assuming they really are angels. They either are functionally different from angels or not. Additionally, from theological viewpoint God is both omniscient and omnipotent, this sets a limit to possible consequences of being fooled. God will not intervene to stop as from being fooled, but having fallible humans be (once again) fooled by false divinity will not actually have any impact on the divine plan for mankind. If God actually exists, no aliens can fool him. As such that the aliens look like angels is largely irrelevant, we should still judge them by their actions. Moreover as somebody noted, if they really are angels, we find them because God wants us to find them, and it happens because God want to tell us something directly. I think we can trust God not to mess it up, we will get the message. We will of course be free to ignore that message, but we will get it, it will not depend on being able to tell angels and aliens apart. As an added note, most popular concepts of what angels are like and what they are about are pretty much nonsense. So even angels looking and acting like we expect of angels would probably be putting on an act to ease the communication. In summary, treat them with the respect they deserve, judge them by their actions not by their appearance, and pay very close attention to whatever they have to say to you. These are all true regardless of whether they are advanced aliens or angels from Heaven. [Answer] It is way harder than one can imagine. The God of Old Testament broke rules exactly three times, when he barah (created) matter, life and human soul. Everything else he oseh (made, built, engineered), which implies nothing supernatural. Any miracle after the Sixth Day either has rational explanation, or is misinterpreted. Your advanced humans are also very unlikely to meet angels (angelic figures with harps and wings are a possibility). I don't want to get deep into the spiritology; in any case an Angel (as the Greek word suggests) is a Messenger; he has no will of its own, and his sole purpose is to convey a particular message from God. Unless God is willing to send an angel to talk to you, you'd not encounter one. Similarly, if you truly see an angel, you'd have no questions like this, even if it appeared in form of a desert vegetation. The question becomes much more interesting if we abandon the Old Testament model. Consider a Neil Gayman's study of American Gods. You know it was God when you become one. Sad news are that that God is already dead. [Answer] What makes you think you need to be sufficiently advanced? AKA Sufficient Technology = Sharp Stick Within history there have been plenty of accounts of MEN who have been able to masquerade as gods. Technology would just make it easier. All one really needs is the ability to alter the very reality that their subjects live within. Which is actually much easier than one really would imagine. Between genocide and torture, one can very easily shape the collective memory of a civilization, until the definition of "divine" and "god" would mean "you". [Answer] Sufficiently advanced aliens are just sufficiently advanced aliens, but you may have case like from SG - where aliens called Goa'ulds are playing gods. They are not much advanced - because they steal technologies to other species (star gates and many more). They may be killed relatively easily (but revived with sarcophagus). And they can die, of course (like Apophis or later Yu). And next aliens playing gods were Ories. Also they were only very advanced aliens (more advanced than Goa'ulds). So, if you would set reasonable rules, you may have very advanced aliens that will be successfully playing gods (until some time - for example, they will meet someone who will think in a way that will make them immune to tricks coming from their advancement). [Answer] Divine beings would radiate power, righteousness and purity. Their moral fiber would be unquestionable. They would literally be and feel out of this world. Sufficiently Advanced Aliens, for all their togas and spires, would have the same questions and doubts as we do. If the encountered beings are themselves riddled with doubt about the meaning of life, the universe and everything, then perhaps we can keep on 'drilling' together. Just be careful that you don't accidentally drill into that other place... ]
[Question] [ I have been working on an RPG (a video game) where one of the key plot "themes" is the prevalence of mercenaries, of very varied capabilities and fame/infamy/secrecy. After lurking answers on here and seeing so many absolutely fascinating/on-point responses to WB questions by others, I figured that certainly there must be very interesting/"obvious" things that I haven't realized or considered. Background: * This is a somewhat surreal and hyperviolent game, so some handwavium and ludicrousness is acceptable (and enjoyable, in theory, if done right). Think Hotline Miami x Skyrim x Metal Gear Solid or Final Fantasy or Zelda, or something. And some Dune inspiration too, as there is something analogous to Spice that has been discovered and become very valuable. * Mercenaries are simply defined as "private" groups that excel at accomplishing tasks due to their physical, strategic, and/or technological prowess. * It isn't 100% necessary that money is the end-all for 100% of these groups, but logically it would be for most/nearly all. * Set on an Earth-like world in the modern or near-future. I can provide some more information if needed. [Answer] I think the real question is why there are mercenaries. For this many mercenary groups to exist there would have to be something inspiring and encouraging it. That implies many fights happening between many tiny nations. In fact this world would work very best if you had no super powers and only lots and lots of tiny nations, all so small that it's too expensive to keep a standing army and it's easier to buy mercenaries for the length of time you need them. The concept of 'buyability' would then be very important. If I have to hand over a good portion of my nations GDP to buy mercenaries to defend it I would be rather upset if the mercenaries then turned around and ransacked it. Thus most mercenaries would have a very high value on keeping their word. Those that are known to break it would never be hired, or not by anyone remotely trustworthy. Since mercenaries are so much stronger, and thus nations probably keep little in terms of standing army, the threat of mercenaries simply moving in and taking over a nation is very high. Of course any sort of group that does this is unlikely to have the skills to lead and keep it strong. Thus some mercenaries may move from country to country, taking it over, using it's resources and then moving to the next Country. This all combines to give a pretty interesting premise for the world. Mercenary corp X was hired to defend a nation but the nations enemies gave them a huge bribe to take the nation out instead. The corp agrees to do so, only to discover that, shockingly, no one will hire them ever again. So they try stay in the nation they were originally hired to defend and simply live off it's resources, but they find the nation is small and without good leadership (which they killed) it starts to fall apart into anarchy fast, they don't want the difficulty of trying to lead, and so they move on leaving the collapsing former nation behind in anarchy. X proceeds to move from country to country, taking out their tiny armies, enjoying it's riches, and moving on when the company inevitably collapses from the lost of leadership and raping of it's resources. Neighboring countries, which formerly didn't bother with large standing armies, are now terrified of being invaded by X and effectively destroyed. They start hiring mercenaries to defend themselves, and suddenly all the mercenary groups around the world are moving in to a small area full of tiny disorganized nations afraid of being invaded. The suddenly influx of so much man power, and such drastic expenditures to afford the mercenaries, then causes odd power disputes. Country Y hires expensive mercenaries because their afraid X will invade them. X hasn't invaded yet, but Y realizes they can't afford to keep paying it's mercenaries to stick around and defend them without eventually going bankrupt. Y decides since their on retainer any way they should use the mercenaries to help cover their own cost and invades undefended nation Z and taking their resources. Z has to hire mercenaries to defend itself and suddenly Z and Y are at war. Some country bordering Z and Y then hires mercenaries simply out of fear that either Z or Y will attack through them to get to their enemy etc etc. Meanwhile none of these nations have the GDP to be able to keep up with the massive expense of keeping these mercenaries on retainer to defend them, the nations are all slowly bankrupting themselves to keep the protection. In the long run even if X never invades the nations risk collapsing when their markets can no longer sustain the massive mercenary costs. It's an unstable and bad situation which looks to get far worse the longer that X is out there terrorizing the nations. In all this you have X as the evil mercenary group to be your antagonist. You have wars suddenly happening all over the place, political nuance (you can glance over it or mock it if its not relevant to your story, but leave it implied in the back story). You have something inspiring all the combat and warfare, and it being bloody and to the death because all the nations feel that their fighting for their very survival and people can be crazy in a mob mentality like that. Your protagonist can be the heroes simply by always keeping their word. Perhaps mercenaries have codes for how they work together. In either case the protagonists ultimate goal is to stop group X. In so doing they can fix the whole warfare nonsense that X accidentally spawned. You get gore and bloodshed while being the good guys, yay! [Answer] Read about the history of Renaissance Italy. It seems an almost exact parallel to your situation: <http://en.wikipedia.org/wiki/Condottieri> One factor you may not have anticipated is that battles between various mercenary groups can degenerate into showpieces, as mercenaries tend to be interested in living to enjoy their pay. [Answer] For a historic model of what could happen, look at [Renaissance Italy](https://en.wikipedia.org/wiki/Condottieri), or more generally, at European warfare between about 1600 and 1800. [Answer] In general, a lack of government (meaning no militarys at all) could work - This is usually explained as a global catastrophe that destroys all large government and everyone just fights for survival. Zombie games or games with a backstory similar to Fallout would fall into this category. --- You could have some new ideology that the world has conceivably decided to adopt. The world creates the "Mercenary Guild" where people can choose to sign up and become famous like any other sport. Conflicts are decided by hiring two groups which fight it out, keeping the general population of the world safe. --- Or, some group discovers technology that puts them far ahead of all the governments and makes themselves the world's police force, made up of many different groups. They manage themselves and won't work in favor of one government or another or some sort - they could completely takeover, but don't. Which is why governments just leave them alone. Not sure why you would need so many different groups though - the world would have to be in a major uproar or something. Perhaps this world police force just had something major happen and split into many factions without any unity. [Answer] In the real world, I consider mercenaries or private military contractors a very bad idea. But bad ideas can make good adventure settings. Capable can cover a great many things. In the real world, serious military forces can operate across a spectrum from internal security operations to major theater war. Private military contractors tend to specialize in things like bodyguard duty during counterinsurgency warfare or rear area maintenance support. One could imagine a world where different contractors specialize in different things -- a mercenary artillery battery, an air assault brigade, a squadron of ASW frigates for hire. Almost by definition, they'd be better at their niche job than full spectrum forces. But no matter how good they are, they would be unfamiliar with the area of operations and the other elements of a combined arms force. Sure, one can hire an artillery battalion to support an infantry regiment, but the artillery forward observers won't have trained with the infantry platoons. And neither one has trained with the logistics company. So you don't hire different mercenaries and integrate them, you go to a general contractor for a turnkey operation. A mechanized division with artillery and aviation brigades plus rear area support services. But how many of these contractors could there be on the planet? Five? Ten? Things look different if the mercenaries operate with the tacit approval of a major nation state. But then they're not really mercenaries, they're not-quite-regular national forces. * A genuine mercenary would be in the profession for the money. Assuming that he is not currently under contract, would he fight for the highest bidder or does he look for politically/morally acceptable causes? * A mercenary might sign up for a force which later comes into conflict with her homeland. Will she be tried as a traitor or do people accept that such things happen? * The employer of a mercenary conducts genocide behind the front lines. The mercenary was not directly involved in those crimes, but he gave his employer the time and space for mass murder. A couple of years later, the other side asks for his extradition to stand trial. * A mercenary has signed a contract to operate an air defense system. In a high stress situation, she fires at a passenger airliner. Can the relatives of the victims sue the mercenary company? How about a class action lawsuit against the (different) company which produced the SAMs and the company which produced the radars? You talked about an earthlike world. Are you talking about a setting with multiple planets and interstellar travel? Having more space and less population density might be conductive to mercenary operations. There are plenty of science fiction settings with these elements -- the Traveller RPG, Drake's Hammer's Slammers, Pournelle's CoDominion series, Bujold's Vorkosigan books, ... [Answer] A bit more tech than you're envisioning, but look at the Hammer's Slammers novels. The basic force driving this is a universe with a large number of small combatants. Most of the time they have little if any military, it's a better deal to shell out a whole bunch of money to hire mercs when needed than to maintain a standing army of anything like their firepower. It gives a good basis for why you could have mercenaries being the primary combat forces. The universe has a bonding commission that ensures the mercenaries actually do the job they're paid for and since it's high tech warfare it generally becomes clear that defeat is inevitable before large numbers of casualties are sustained--and thus the loser usually doesn't get torn up too badly. [Answer] I think the "Implications of a world where mercenaries are more capable than most militaries" would cover a lot of ground, but lets start with why governments might prefer to hire a mercenary group rather than maintain a standing army. A few of the other answers mentioned that small nation states may favor mercenaries, but I can definitely picture large powerful nations employing mercenaries... After all, [The US has the largest military in the world, but they still hire out](http://en.wikipedia.org/wiki/Academi#Iraq_War_involvement). So, in your scenario why might even large wealthy countries prefer to contract this kind of work rather than handling it themselves? [Plausible Deniability](http://en.wikipedia.org/wiki/Plausible_deniability) Large powerful nations may not want to be seen doing ethically questionable things. Say nation X wants to attack and weaken nation Y, but doesn't want to deal with the scorn of the international community, (you know... sanctions, broken alliances, and so on...), they could hire out their dirty work to a private firm under an obligatory non-disclosure agreement. Nation Y would strongly suspect that nation X was responsible for the attacks and in turn would hire another contractor to retaliate. You end up with [proxy wars](http://en.wikipedia.org/wiki/Proxy_war) between somewhat nation-less mercenary groups, while both nations X and Y claim to have no direct control or involvement in the conflict. Of course the above only works if the mercenaries don't expose who they've been hired by, but that could very easily be handled by a chain of command. Ground forces probably wouldn't be privy to that information. The details of contracts would simply be way above their pay grade. One way you could explain how these mercenary groups grow to rival and overpower national militaries could be the [scope and profitability of private industry](http://www.businessinsider.com/25-corporations-bigger-tan-countries-2011-6#walmart-is-bigger-than-norway-25). Lets say that rather than hundreds of small mercenary groups you just had a handful. It would be a bit like pitting a company like [Apple](http://www.businessinsider.com/25-corporations-bigger-tan-countries-2011-6#apple-is-bigger-than-ecuador-11) against a company like [Microsoft](http://www.businessinsider.com/25-corporations-bigger-tan-countries-2011-6#microsoft-is-bigger-than-croatia-12) in an armed conflict. Or worse still, if you wanted an interesting plot twist, you could have one global mercenary conglomerate which maintained a monopoly on the market. When wars broke out it could be, lets say the Northwest Division VS the Southeast Division in a proxy war, none of the troops on the ground would be aware that they're employed by the same firm, nor would the nations hiring them. The conglomerate controls the outcome of all armed conflict in a way that maximizes long term [profiteering](http://en.wikipedia.org/wiki/War_profiteering). Picture a company a bit like the [Umbrella Corporation](http://en.wikipedia.org/wiki/Umbrella_Corporation), from the [Resident Evil](http://en.wikipedia.org/wiki/Resident_Evil) series. ]
[Question] [ I'm trying to write a murder mystery in a fantasy setting without much technology - certainly no DNA or fingerprint evidence - but I've realized that I have no idea how they would go about solving the crime. What techniques would investigators use? The technology level is pretty much standard medieval, and while I will be flexible to a degree on when techniques were first used, I don't want anything that came after or during the industrial revolution. This is a fantasy world, so I'm open to magical methods (but I'd like some more scientific methods as well). Necromancy came to mind, but there's a number of in world restrictions on communicating to the dead: 1. You need part of the dead's body, preferably blood. Hair or bone might work too. 2. You can only connect with spirits from certain cultural groups because not everyone's spirit goes to the same place. 3. There's a minimum number of days it takes before the spirit of a dead person can be contacted. 4. Even once those days elapse, the spirit may not be there. 5. You can look for the relatives of whoever's blood you have, and try to work backwards, but all the same restrictions apply. [Answer] In this setting, laying aside magic for the moment, there are still some basic investigative techniques that may be used. These fall generally into the categories of human intelligence and forensics. Since even today, most murders are solved in the first two days after the crime, if necromancy has a minimum elapsed time restriction before it can be used, this may well be outside the first 48h, and so would be used only on the more difficult cases. Human Intelligence Human Intelligence is basically the matter of having the investigators interview the suspects and witnesses, either formally in an interview room, or informally wherever they may happen to meet. The techniques of interviewing suspects and witnesses has changed little for hundreds of years, and does not depend upon technology. Assuming that the investigators eschew torture for whatever reason, either that they recognise that confessions or information so obtained is unreliable, or simply that torture is illegal, a good investigator can still spot and pursue inconsistencies in a subject's dialogue, and determine who has good alibies or not. Forensics Forensics has also existed in some form for hundreds of years, though in a pre-industrial-revolution society, there would of course not be the many scientific tests that we have these days. Still, that leaves many options: 1. Autopsy. A person who has been murdered will likely bear the traces of the means by which their death was procured. This may be tool marks from a penetrating or blunt instrument, or the residue of a toxin or whatever else. Where magic may exist and could be used to kill, it is likely that there are forensic magicians as well as forensic doctors, potentially being the same person. 2. Crime scene analysis. The spilling of blood may leave distinctive patterns that show how it was spilled, in what order events occurred, and may even show the outline of the killer in a void in a blood-spray pattern. The murderer may leave traces of himself, in the form of hair, fibres, footprints, etcetera, and may take away traces of the crime scene. It may be more difficult to connect the two than is the case now, but not impossible, and the importance of such evidence would be lower, but not nil. Magic While necromancy is quite limited, there may also be magic for determining the truth of a suspect's or witness's statements. In fantasy, such spells typically give a true/false reading, or may be more sophisticated, able to give a partial-truth and/or evasive response indication. This would, of course, only show what the subject of the spell believed to be true, and there may be spells that alter a person's memory of events, so that they can tell a 'lie' and still appear to be truthful under such questioning. A particularly clever killer might even have his own memory of the event altered, so that by the time an investigation reaches him, he may no longer know that he committed the crime, and may have an entirely different memory of the time in question. However, if a suspect is a magician, then the possibility of this must be considered by an investigator, and if the suspect is not a magician, then the magician who performed the memory alteration may be locatable and could also testify. If it was not illegal to alter a memory at the request of the person whose memory was being altered, then it is quite likely that such a practitioner could be persuaded to testify against a criminal in order to avoid prosecution as an accessory to the crime. However, this would require that the investigators find said practitioner. Another common trope in magic is the law of contagion: once two items have been connected, they will remain connected, though the time for which this connection persists varies according to setting. The law of contagion can be used to magically locate the missing part of an object or collection, or the person whose hair/fingernail/etc. was left at the crime scene, or whatever else. This could be as simple as [dowsing](http://en.wikipedia.org/wiki/Dowsing) (this is a considerably broader and more complex field than this Wikipedia article suggests, whole books have been written on the subject), or could be some sort of visual scrying. Even limited to dowsing, a good dowser could follow the path a killer had taken after leaving a crime scene for some distance, probably up to the point where that person crossed moving water in some sort of craft or by swimming. [Answer] Too long for a comment, not adding enough for a proper answer but hey... Try reading some other historical crime fiction such as the "Cadfael" series by Ellis Peters for some insight into realistic and (relatively) well researched Medieval crime investigations. Terry Pratchett's "Diskworld" series has something similar in a fantasy setting in its "City watch" subseries. The proceedings of the Old Bailey ( <http://www.oldbaileyonline.org/> ) will also provide some context on how crimes were investigated and prosecuted just a few decades later (it starts in 1674). edit: more Cadfael as it seems to be making me popular Cadfael ( <http://en.wikipedia.org/wiki/Cadfael>) is about a fictional investigator/herbalist/monk who had previously fought in the crusades and took holy orders at Shrewsbury Abbey in the mid 12th century. Being so far back in time Peters had to restrain herself to techniques that would have been available at the time. Cadfael's knowledge of herbalism and plants (with their native locales) was one of the key ideas along side his previous occupation as a soldier. Together these allowed him to use plant clues to work out where the victim and suspects had been, as well as where poisoning may have occurred, and his medical and combat knowledge to understand wounds and their age (etc.). Cadfael's position as a monk and healer make him popular in the community (who doesn't like a nurse or priest?[sic]) and so people talk to him willingly where they would not talk to the authorities, particularly at a time of civil war, such as was being fought at the time. The accuracy of the ideas in the books is covered in [ Kaler, Anne, K (ed) (1998) Cordially Yours, Brother Cadfael, Bowling Green State University Popular Press ISBN 0-87972-773-X ]. The books are well written and easy to read and, as commented the great [authors view] sir David Jacobi starred in the eponymous role on the UK's ITV between 1994 and '98, both are recommended. When it comes to the more forensic ideas some other posters have suggested things such as autopsies which, to our modern minds, seem normal and uncontentious but you should bear in mind that for cultural and religious reasons such things were seen as taboo. Dissection was illegal throughout Europe for a very long time and bodies were buried very quickly after death (c.f. being found), removing body parts as part of an autopsy could be seen as witchcraft and end in you dancing the Tyburn Jig (early modern grim hanging humour FTEW - very few if any witches were burnt; most were hung). Even if playing around with bodies is not illegal in your world, will all of the superstitious serfs be happy for you to desecrate the body of their loved ones or will a lynch mob form and fill you with pitchfork holes? Remember that the early anatomists (such as Michaelangelo and Leonardo Da Vinci) had to resort to grave robbing to get their victims and had to hide how they got all of their detailed knowledge. Medicine until the 19th Century didn't really go in for knowing what was inside the body and generally thought that human insides were humorous ( <http://en.wikipedia.org/wiki/Humorism> ). tl;dr for last paragraph: in modern times the worst people will do if they don't like your investigation is refuse to answer your questions, in those times you were in serious risk of a horrible, crispy death. edit: a few more ideas Remember that magic need not be used just to ask the dead questions; if you have a spell that can compel someone to tell the truth you can gain a lot of information that you wouldn't otherwise have, especially if that spell (or another... or torture) makes them talk as well. Magic may leave traces of itself that investigators can follow like footprints in the air or magic use could be scried from a person's body. On the other hand magic can make it harder to detect the real criminal if they use it to implant false memories in others (perhaps even memories of committing the crime), to erase witness memories or even to make the murder look like a tragic accident (force push off a cliff?). There are lots of ways that a medieval detective could work using things that we now base in science as if it were magic, perhaps even as far as fingerprints or DNA with some thought. Remember that one of Clarke's laws is that "Any sufficiently advanced technology is indistinguishable from magic.", and it applies backwards as well as forwards! [Answer] Disclaimer: I'm not a police officer, detective, law enforcement official, crime scene investigator . . . You get the idea. That said, here are some ideas: * Ask witnesses. Don't laugh; this would probably be a best shot for a police force (or it's equivalent). There aren't any security cameras, microphones, or any recordings of the crime. You have to ask someone who as there. Unless you have talking animals, your best bet would be to ask any human that was nearby. Just be sure that s/he is telling the truth! Bribery by the murderer is possible. If the witness in question is a peasant, s/he would be willing to take money for lying. * Torture This becomes a very real possibility, especially if (as is discussed in the next example) the people in charge aren't so nice. Choose your method of choice: [The rack](https://en.wikipedia.org/wiki/Rack_(torture)), [the Iron Maiden](https://en.wikipedia.org/wiki/Iron_maiden_(torture_device)), or just tickling the person until they tell the interrogators what they want to hear. Choose wisely. There are some benefits to medieval-era torture: A) Just the threat of it is going to scare the heck out of any potential witnesses; B) It's likely very much legal. * Make up a scapegoat. Don't laugh at this one, either. It's probably not what you're looking for, but it's a possibility. If someone gets murdered (Especially a nobleman), the locally bigwigs are going to want to catch the person who did it because that will make them look better to the general populace (come to think of it, this would be less important if there weren't elections, though a leader still wants the support of his/her people). What if you can't find the killer? Pick a scapegoat, any scapegoat, preferably a rival or enemy. Doctor the evidence, do what you have to in order to place the blame squarely on his/her shoulders, and execute him or her. This is going to lead to a conclusion that's most likely not what you want. It's unsatisfactory, especially if your protagonist is a police investigator, or a relative of the dead person. An interesting plot twist, though, would be to have your protagonist be accused (and tried, and found guilty) of the murder. You can therefore have a tragic ending on the gallows, or a daring Jack-Sparrow-esque escape (I believe that a folktale involving Robin Hood had a similar scenario). You then have a dashing outlaw, sure to gather the support of the surrounding people, especially if they think he's innocent and the ruler(s) is/are corrupt. Viva la revolución! These aren't too scientific, and (while almost certainly used in the past) may not be the most effective methods, although I don't have any better ideas. . . [Answer] Historically on Earth, evidence-based criminology wasn't invented until after the industrial revolution. When Arthur Conan Doyle wrote his Sherlock Holmes stories, the scientific approach to solving crimes was more or less a new idea. Medieval law enforcement of a mysterious murder is to raise the alarm and look for people running away, or with bloody weapons, have people run around looking for who obviously did it, then if that doesn't work, question people. Fortunately (or tragically, for potential innocent accused), you don't need much evidence. You just need to convince the local ranking noble to listen and care and believe you enough. Or if the suspect is noble, depending on local laws, you might be able to challenge them to single combat. God knows who's right, and will see that the right person wins. Or you can consult what local magicians or diviners or sages are available. Or if you suspect the assassin was from some group, you can threaten other members of that group to turn over the assassin, or exact some retribution you invent. [Answer] As [Dronz](https://worldbuilding.stackexchange.com/a/4911/95), investigation was much less evidence-based before modern era. It was mainly witness-based, with "witness" in a different sense than we understand it now. If nobody saw the crime, then typical "witness" was a village elder saying that all the villagers but the suspect couldn't kill their neighbor, because the elder knows them as honorable people. Two or three witnesses were usually necessary, but their status played some role and one nobleman's doubtful testimony could weigh more than testimony of a whole village of peasant, even if they seemed right. The details depend on culture, on the judge's personality etc. There were cases when evidence outweighed testimonies however. Finding the murder weapon with someone was almost clear. Separating witnesses for interrogation and asking questions that could prove false testimony was a common technique. Another one was scaring the culprit to make him panic and run away or do something else that "proves" he is guilty. Nobody mentioned [ordeals](http://en.wikipedia.org/wiki/Trial_by_ordeal) yet - for most of prehistory and middle ages, this seems to be the default solution of truly mysterious crimes, where techniques mentioned above didn't prove who did it. Some ordeals were just ways to make the culprit show his guilt - such as telling everyone in the village that some magical ash will make blisters to those guilty and then arresting those who didn't touch the ash. In other cases, some supernatural sign was required to prove innocence (walking barefoot on burning ploughshares) or guilt (a witch won't sink when thrown into water). Close to ordeals were [trials by combat](http://en.wikipedia.org/wiki/Trial_by_combat) - the innocent was supposed to win. With fantasy-like magic, there are basically three possibilities: either the mage is just a witness as anyone else (though perhaps with high value), no matter how sophisticated his magic is. Or the magic is somehow used to supplement ordeal - the judge uses a spell and tells who is guilty (ordeals are a kind of magical investigation as well, just without classical fantasy magic), and judge's whim or critical failures on divination are easy to hide. The third possibility is that the magic produces evidence comparable to modern forensic, and it is recognized as such. In this case use Monty Wild's answer and don't try it to ressemble medieval investigation more than is necessary. Perhaps you can combine all three: in your situation, the investigation would have three stages: first few days, when human intelligence and mind magic plays primary role, then use necromancy and other divination not available in the first few days, and then an ordeal if the second stage doesn't lead to solution, or to "prove" that the mage didn't manipulate the process. [Answer] Step 1 Go where the last meal(s) of the victim were, and make sure you get a sample of everything. That for testing if it is poisened, use arrested pagans/prisoners/slaves to test various food items around... if they die of one of them, test again... if the second one dies too, you know it is food poisening. (might promise them amnesty in heaven for their crimes if they are working along or just see it as a death conviction) If you find poison, use alchemy to find out what it was. step 2 : In order to get to the body's, either BE the priest, the grave digger or some other person that gets easy acces to the body's. (your detetive work is off the record for well paying insiders, or out of curiousity -> after all many priests were themselve of nobility, so they might want to just have a hobby, or feel obligated to their family) Once you got acces to the body's, do NOT dissect them (medieval medicine would not know what to look for, but look for outward signs, pale skin, foam mounth, color of the tongue, eyes, etc, could all be signs of poison. If the cause was foul play, this should also show clearly in the form of stabwounds, cuts or bruises. -> if you see clear signs of foul play, than a little reconstructiv work in the torture chamber (punished prisoners are plentyfull) and start testing untill you find your murder weapon. You can also observe the body for the limited signs known of decomposing.. (bloating, maggots and such, while this knowledge is VERY limited in these times, it gives a very rough estimate in were it hours, days or weeks this person has been dead.) Now test that soliva and blood on poison by basic alchemy.for poison. (if you want to keep in the period, also extract some black and yellow vile, and test them as well) You now have your suspected method of killing \poison \assault \*witchcraft (anything that does not fall in the first 2 cathogories) step 3 : Now you could just starting asking questions, but your cover would be pretty soon blown and you dead, besised your assasin likely worked in order of somebody royal and he/she SURE is not going to talk. So your method is : see who get to gain the most by the dead of your victim, that is your most likely assasin-ordering person. This is simple as for royality this is just prestige, power, titles and MONEY, very easy to track and to get informed about without needing to ask suspicious questions. Now in order to get that person to talk, you do a little poison mixing of your own, nothing deadly, but by either grind a little dust of the diseased, or just the right herb in their drink or meal, you can make them properly sick.. (small change of them dieing of that.. so you won't do that if you like the suspect to much) but if you are a sociopath or don't care for the target more than the truth.. go ahead.. now since YOU were the priest and they think they gonna die... they will give deathbed confession to you, INCLUDING that plotted assasination... if they did it, rest asured hell to such people is fearfull thy will not keep that out, so if they are not admitting, they not done it. in the case your first suspect turned out blank, you go onwards with this practice.. if you hit a dead end (no proper gain people more can be found.. exclude poison and/or assault, it is witchcraft!) step 4 : blind accusing. So it's witchcraft, great! now you just point at the most hated person in town (or somebody random you want to get ridd of for whatever reason) and she/he be tested the way witched are tested.. either burned at the stake (oops she burned to crisp, she was not a witch, alas).. or dipped in the water (oops she did not came afloat, she was not a witch) or have her weighted on a scale (ah great find the lightest person and she sure be guilty <50kg = witch) and THAN burned or drowned. That way the people will always be suspicious, and in those times that means guilty. Your job is done, does not matter if the real killer is still out there. [Answer] One of the worst mistakes an author can make is their world and its characters not be based enough in reality, so I'd suggest staying away from anything magical solving a crime, even in a Fantasy setting. There were methods in Medieval times for solving a crime. Do your research that includes diving into it on your own and asking those expert in the era from which you wish to borrow (university professors of the Medieval era would be a great place to start - most are extremely helpful). You'll be better off learning what you need that way than getting advice on a public board. An excellent example of Medieval mysteries and crime-solving techniques can be found in the Sister Fidelma series by Peter Tremayne: <http://www.sisterfidelma.com/tremayne.html> [Answer] There is an issue with your basic premise, which if you are happy with, then fair enough, but it is that the scientific principle did (could?) not exist in medieval times. Might was Right and wisdom was revealed not preceived. You could have an individual who applies observation, common sense and logical reasoning to work out a possible sequence of events and then questions witnesses to confirm or disprove theories. Such an individual would probably have a hunter/game keeper background to have the observational and reasoning skills, which would make them lower social caste so making it difficult to do anything other the converse with witnesses, and even then only lower social order ones. One aspect you could have some fun with is your societies attitude to murder. It would be very different to modern attitudes. [Answer] Not medieval per se, but if you want a great example of some pretty traditional criminal investigation alongside a well described/internally consistent system of magical forensics, you should have a look at Randall Garrett's "Lord Darcy" stories. These are set in an alternate 19th Century-ish setting with magic based devices replacing many of the later industrial/Victorian technologies. ]
[Question] [ Behold, a crocodile. The only thing that they have to worry about is hunger when they cannot catch a meal, and camouflage that is better than the eyes of their prey. What if a species of mushroom started growing on their skins in a symbiotic relationship. The fungus provides camouflage and the croc provides a meal. If enough radiation were induced to fuse the two entities together, could the croc have offspring born with mushrooms? And is this plausible at all? Thanks! EDIT: Maybe check out the Mesodinium chamaeleon? It’s part plant part animal. [Answer] The croc offspring could acquire its mushrooms shortly after birth. Lots of things have commensal organisms. We are loaded with them, inside and out. They help us in many ways, not least of which they keep worse things from moving in. They are good renters, a lot of our commensals. It is tricky to pass a commensal along the germline. Almost always the commensals move in after the fact. It is a lot easier for young to acquire them as soon as they are born. We get ours via close contact with our mothers. Some of her commensal organisms get on us and become ours. Your croc could do the same. Perhaps a shroom croc rolls in the nest before laying eggs. She is not planning ahead for her young because she is not that smart, but her ancestors who rolled in their fresh nests had better genetic fitness than those who did not, just as long before them the ancestors which built nests at all had better fitness than those that did not. Fragments of her mushroom colony break off and remain in the nest. Then when the young hatch, they crawl around on those mushroom fragments which take root. A new generation of shroomcrocs! [Answer] Fungus reproduce by spores, so the host would pass on the fungus to others through interplay. Many pathogens are indeed fungal in nature like [Histoplasma](https://en.wikipedia.org/wiki/Histoplasma_capsulatum), [Pneumocystis](https://en.wikipedia.org/wiki/Pneumocystis_jirovecii), and [Cryptococcus](https://en.wikipedia.org/wiki/Cryptococcus_neoformans) this are just three examples of pathogenic Fungus. as a matter of fact, fungus is a pathogen type playable in the game [Plague Inc.](https://en.wikipedia.org/wiki/Plague_Inc.) also, if the spores enter the reproductive track, then the offspring could contract the disease as well. [Answer] ## Pre-birth infection You are covered in microflora both on the outside and also on the inside - both your mouth and genital tract are colonized by various microorganisms. A symbiotic fungus living on the crocodile skin would likely also live in their cloaca. While ovaries generally are sterile, it seems quite feasible to imagine the fungus infecting the egg during the fertilization process, moving in together with the sperm, in which case the fungus (or its spores) would arrive before the egg shell is formed, and thus could be on the exterior of the egg yolk but inside the shell. [Answer] A woman with a nut allergy received an allergic reaction from coming into contact with her sexual partner's semen. As it turns out, the partner ate brazil nuts a few hours earlier, and as the brazil nut's protein resists digestion, it can actually be passed on sexually. [Link for reference](https://pubmed.ncbi.nlm.nih.gov/17583107). Based on that real life event, there's plausibility to a fungus being able to pass itself on via the reproductive cells of an animal, thereby infecting at least the mother (even if not the child). Given animals' tendency to at least somewhat interact with their offspring, or to at least be in the vicinity when they are born, transferring it from the mother to the newborn doesn't seem that far-fetched. I'm no biologist, but even if crocodiles were to lay an egg and immediately abandon it, you can argue that the infected mother ended up contaminating the egg shell itself, and when the shell is broken when the youngling emerges, it releases spores which the youngling breathes in. [Answer] Read about [mitochondria](https://en.wikipedia.org/wiki/Mitochondrion#Origin_and_evolution) They are believed to have originally been symbiotic cells in humans most eukaryotic organisms that are now passed on by mother. It is the only part of the body that contains DNA only from the mother. ]
[Question] [ In redesigning a large number of my ships, I've decided that having larger ships generate enough power for FTL was too convenient and made balancing the factions varied FTL methods difficult (both for writing and game development.) To work around this, I'm moving the ships towards having large banks of capacitors/batteries that store energy for later use (FTL or other power-intensive equipment.) The ships would need to recharge off their reactors between jumps/warps. This also presents a new weak point on many of these ships, I think. Ships are powered by fusion reactors (plural for redundancy reasons) and store the excess power that isn't running the ship into capacitors and batteries for later use. These capacitors and batteries would likely work similar to those we have today but with advances in energy storage density. Fusion reactors have the added benefit of being the "safer" forms of nuclear power in that a runaway reaction is not possible as fuel is added on demand and to maintain the reaction. If a system fails and takes away conditions needed to maintain fusion, the reaction ceases. Contained heat and energy might disperse into the local hull, but the rest of the ship would likely survive. Batteries would be used for taking over powering ship systems in the case of a local reactor failing while the nearest reactor transitions towards higher capacity of output to compensate. Capacitors would be used for systems that require all of that energy in an instant: massive weapons with slow firing cycles and various FTL drives being the two primary examples. Both of these capacitors and batteries would function much like what we have presently, only with advances in energy storage density. Batteries storing energy through chemical reactions and capacitors storing the electrons themselves. If these ships were storing massive amounts of energy, astronomical by our standards since we are talking about faster than light travel, I could imagine damage to these banks causing a catastrophic discharge of the energy contained. Something that would likely vaporize the ship in a near instant along with anything nearby. What would likely happen if they were struck in combat or something collided with the ship? And are there means to prevent this violent discharge, protect the ship itself from it, or redirect it away from the ship? If it could be directed, I can imagine fleet formations being set up so that friendly vessels are never in the path of these discharges. [Answer] Watch [this overly gratuitously destructive video](https://www.youtube.com/watch?v=NOVOON4lJog) of some poor normal capacitors. Those are low-voltage low-capacitance capacitors. And they still have a decent amount of force to them. A high-voltage high-capacitance capacitor would be, in a word, cataclysmic to anything nearby. Something powerful enough to power a FTL drive would probably completely destroy the ship it was on, regardless of size. Modern capacitors are fairly safe from exploding via impact. The linked video was done via giving them too much power. The most likely thing would be that they simply stop working, or damage causes them to short - Releasing all of the power extremely violently in a very short period of time, as seen in [this video](https://www.youtube.com/watch?v=gj1pkyCL75E). If it's metal that's causing the short, it will heat up and melt and cause all sorts of problems - And that's only for bare metal. Other materials, especially thing with water, will expand and explode. Woe to the poor sap that ends up being the path of least resistance for a discharging capacitor. Having a capacitor explode is, in my thoughts as an electronics tinkerer, very unlikely. Having them cause all sorts of havoc when damaged? Totally possible. To address fleet formations and the like - Space is huge. Absurdly huge. A "Close" formation of space ships will likely be outside of visual range, with hundreds of kilometers being absurdly close. No realistic weapon or destructive event caused by even a hypermassive ship should be large enough to make even "Close" ships blink, unless those ships are moving in to dock, perhaps for boarding or rendering aid. Still, those types of actions are likely easier done via smaller craft such as shuttles. [Answer] There is a very big difference between how traditional batteries and capacitors store electrical energy. In a battery, the energy is stored chemically. That is, a chemical reaction occurs which produces free electrons, available to do work. This chemical reaction takes time, meaning all of the stored energy is not immediately available to do work. In a rechargeable battery, this chemical reaction is reversible. That is, when electrical energy is put into the cell, the chemicals store this energy by changing back to their original chemical composition. In a capacitor, it is the electrons themselves that are crammed in to a small space. They are immediately available. No chemical reaction is necessary. They are, basically, like static electricity or lightning. A huge bucket of electrons, waiting to be emptied. This bucket can be emptied all at once if the path is of low enough resistance. The difference is sort of like storing water in a water tower, immediately available (capacitor), or like storing it in ice, available only once it is slowly melted (battery). Thus, overall, capacitors can do much more immediate damage than can batteries. However, batteries can store a lot more power overall. There is only so many electrons you an cram into a small space. Chemicals can be stored in much greater volume. EDIT The risk from batteries is primarily from chemical reactions (exploding gases and such) but the risk from capacitors is electrical (discharge of huge quantities of electrons). Incidentally, the videos of exploding capacitors are chemical explosions from the overheating of the chemicals in the capacitor, and not directly related to electron discharge. A video of the dangers of capacitors would be, for instance, the image of a human still in shock and catatonia several minutes after accidentally discharging a capacitor through their body. Discharging a nine volt battery across your tongue is a mild jolt. Discharging the same size capacitor across your tongue is literally a mind-blowing, mind-numbing and potentially heart-stopping seizure, and definitely not recommended. A definite 'Do not try this at home' kind of thing. Note that I said traditional batteries. Lithium ion batteries act a lot like a capacitor. They can store huge amounts of free electrons, available for immediate release. That makes lithium ion batteries much more dangerous than traditional batteries, and why there are so many horror stories about lithium ion batteries exploding and causing severe damage and fires. They have much more electrons available for immediate delivery. Another safer type of electrical energy storage is the hydrogen-oxygen rechargeable fuel cell. In this storage device, hydrogen and oxygen are combined to produce water, and lots of free electrons. The water can be chemically broken down back to oxygen and hydrogen by passing electricity through it. In this case, the storage element - hydrogen and oxygen - can be stored a bit more safely in pressurized tanks. However, hydrogen still goes boom in the presence of oxygen. So, in summary, you have a trade-off in storage techniques. The electrical energy can be more safely stored in larger amounts using chemical batteries, but it is not immediately available all at once. On the other hand, electrons can be stored directly, and available for immediate release, but much more dangerously and in smaller quantities. [Answer] You could have your storage units blow up, or melt, or whatever you like. But here is an idea for prevention: These energy storage units put their energy into the FTL mover - warp drive or what have you. Any energy output from them warps that battery and the surrounding area of ship a distance corresponding to the energy output. To move the entire ship, the storage units are triggered in unison and the ship moves as a piece. If one battery triggers accidentally or via damage, it will warp off on its own, carrying its section of ship with it. Bad for whomever is in that section of the ship with the damaged battery but good for the rest of the ship, because the damaged battery moves off through warp space and is at a distance if it melts or explodes. A ship like this would be modular with sections closed off from each other. The ship would still function with pieces missing due to battery damage. If this is for a game one could calculate exactly the damage done because that piece of ship with damaged battery would just be missing. A damaged battery moving FTL with a piece of ship around it might whack into something, or whack into something and then explode. It would be fun to have the direction of warp be random. The damaged battery might not blow up, and crew members who move off FTL might not be killed. They could wait in their ship section and hope for rescue. Or if that piece of ship has weapons or engines the crew might be able to do more. This decentralized aspect of this ship means these sections could also used as escape pods - if the ship is boarded and soon to be overrun the crew could trigger each battery and adjacent unit and have them warp randomly away. Under these controlled circumstances the modules (and crew if they are lucky) might be recovered later and go back to war. The modular ship structure will make it easy to improve and augment ships with additional modules. A badly damaged ship could hook its useful remaining modules onto another ship mid battle - salvage on the fly. It would be painful if your expensive new weapons module got the battery damaged and warped itself off into space. It would be delightful if you found a mysterious derelict weapons module adrift in space after its ship destructed - hook it on, charge it up and you are good to go (if you can read the instruction manual...). [Answer] # Really bad things Capacitors store lots of energy. All that energy desperately wants to just be at equilibrium with the rest of the universe. Normally, we make it work hard to reach that equilibrium by powering laser guns or FTL drives. But, should a short happen in the capacitor, all that energy will equalize as quickly as possible. While the [following](https://www.youtube.com/watch?v=gj1pkyCL75E) isn't a spaceship, it's a pretty good idea of what will happen. This is a [better idea](https://youtu.be/D8EQPx-ptKk?t=18) of the results. Now, confine all those hot gases in a big metal tube that can't dump heat (space is a great insulator) and that spaceship is going to have a really really bad day. # Prevention Just like with modern warships, the powerplant is the most protected area of the ship. The [citadel](https://en.wikipedia.org/wiki/Armored_citadel) is the most protect portion of the ship. I see no reason why spaceships will be any different. Emergency capacitor ejection options would certainly be installed too. [Answer] You have an immediate risk with capacitors, referred to as an RCL or CL tank circuit. It is the circuit used in Taser-like devices to amplify the voltage of a battery to huge values. A capacitor stores a great quantity of electrons, available for almost instantaneous release (the C). Coils store a great deal of electrical power in the magnetic fields around the coil windings (flux, or the L), but only while current is flowing. When the field collapses suddenly, there is a tremendous voltage induced - giga-volts potentially. Thus, in an CL circuit, the capacitor slowly accumulates the electrons as it charges. They are suddenly dumped (discharged) into the coil, building up a huge field. The capacitor then fully discharges, no longer sustaining current flow to energize the field, and the field collapses suddenly. This collapsing field produces an induced EMF that 'pushes' the electrons back into the capacitor, charging it again, but at a higher voltage. The cycle continues over and over, and with a minimal resistance (R) the charge can be kept resonating for a very long time. In a super-conductor, for years. In a Taser, this tank (as in storage tank) circuit is taped to produce a huge current flow at a very high voltage. Here is the thing. This tank circuit resonates at a particular frequency. If just a very small voltage and current are applied at the mid-point, in each cycle, the circuit will continue to build up higher and higher current and voltages (like a small push on a swing makes it go higher and higher). So, back to your risk factor. A spaceship has all kinds of sources of circuits that produce magnetic fields. Motors, generators, wiring throughout the ship, even the steel hull itself. If a capacitor were to suddenly discharge into the ship generally, an astronomically huge field would be instantly created surrounding the entire ship. When this field collapses just as suddenly, the voltages produced would be in the tera volt range. Read: a massive EMP discharge. It would fry and take out even the most hardened of circuits, and produce a great amount of heat everywhere instantaneously. I can imagine the weapons systems would make extensive use of CL circuits to build up the necessary energies required to instantly discharge and fire them. So, the trick is to keep your capacitors completely isolated electrically from the rest of the ship, so they can not somehow short and discharge into the ship's systems generally. I expect that they would probably be put in isolation pods separate from the ship by a long mast that could be instantly severed. This, coincidentally, makes them very vulnerable to attack. Alternately, they would have to be placed in a thickly electrically insulated (probably meters thick) compartment in the ship, so that sharp projectiles of metal could not pierce the capacitor and short it out into the rest of the ship. Incidentally, this CL circuit is of great concern to automotive designers of electrical vehicles. Li ion batteries are like capacitors, and the rest of the car is like one big coil. A potentially huge CL tank circuit. Short out the battery into the metal of the car, creating an instantaneous magnetic field, and you have one enormous Taser discharge as the field collapses - substantial enough to create current flow at extremely high (kilo or mega) voltages at multiple places throughout the car. This creates sparking, arcing, and overheating conditions throughout the car instantaneously. It also presents a severe risk to fire fighters and other first responders. Water is an excellent conductor, and will discharge (short) these batteries very quickly. Insulating and isolating these batteries, and waterproofing them, is a great concern to the designers, and a major consideration in getting them approved by safety regulators. Remember the 'flux capacitor' of 'Back to the future' fame? The CL tank circuit is it. Flux is another term for magnetic lines of force. Combine a capacitor with a flux-producing device (coil) and you can deliver unimaginable quantities of instantly available voltage and current - the gigajoules of the movie - from low voltage sources. Getting it small enough to fit in a car is the challenge. [Answer] Your problem isnt the battery getting damaged. In fact, that isnt even a big deal. The problem is one of charge and electrical field. Did you know there is such a thing as an electrical black hole? They can theoretically exist. In fact the equation for electric is identical to gravity. We just don't have negative mass. Thats all. The only reason we dont see them in nature is because the charge would almost instantly be balanced out by the opposite charge. Consider the sheer charge. Its enough to accelerate to 3 \* 10^8 meters per second. Simply put, you are dealing with energy on the level of general relativity. Your bettery doesnt need to be blown up. If it so much as has one of its plates (assuming a parallel plate battery) tilts then every negative or positive particle (proton or electron) will be instantly ripped toward the battery. There is no defense here. If the battery is damaged you dont have an emp or an explosion. You'll have a violent implosion resulting in potential nuclear fission from protons/electrons bombarding your hull at the speed of light. If your hull can survive that then by all means you dont need offense. Just use your batteries as a weapon. I should also point out that charge goes both ways so your ship will also have all its electrons ripped away and flung at light speed. Once again, there is no defense. To put it simply, encase your batteries in the hardest most defending point in your ship. If they get dented, you and the surrounding mile radius can be obliterated by what can only be deemed as a weapon of planetary destruction. [Answer] The main problem with direct electrical storage (capacitors), kinetic storage (flywheels) and localized chemical (batteries), when used to store huge amount of energy, is all that energy may be discharged (almost) instantly in case of disruptive failure either internal to battery pack or even external to it. Such a failure is bound to have catastrophic consequences and is very difficult to prevent because actual place of release depends on specifics of failure. The only (currently available or conceivable) way to limit damage is to use chemical storage with separate storage of reagents and use a reversible process, possibly in the form of power cells. As explained in [another answer](https://worldbuilding.stackexchange.com/a/96950/38942) to a similar question, (currently) easiest is $2 H\_2 O \Leftrightarrow 2 H\_2 + O\_2$ which can be efficiently performed by electrolysis/fuel-cell and necessitates of three independent, separate and possibly jettisonable containers. Note this is actually quite similar to [Justin Tyme](https://worldbuilding.stackexchange.com/a/96931/38942) answer (which I upvoted) but it apparently didn't appear to answer question, which was about Batteries/capacitor risks and ways to prevent them. [Answer] If you have fusion, then you can pretty safely assume a couple of requisite technical capabilities. First you have superconductors to generate the high gauss fields to contain a plasma, and second you have magnetic containment "bottles" for said plasma. This puts you in the ballpark of having the means to store anti matter. Since you have a 100% conversion of matter to energy when hydrogen meets anti hydrogen, the only obstacle to solve for a ridiculously high gravimetric energy density is how to get the increase the density of stored anti matter. Strictly on a speculation basis, I would propose the following solution: Your FTL drives operate continuously in one of two modes. Travel mode generates a displacement used to move the ship. This mode requires a great deal of power. Storage mode also generates a displacement field that is merely used to make a heavily curved spatial area such that the inside is a lot larger than the outside. A much smaller high gauss field can then store a large quantity of antimatter made by accelerators fed from other fusion drives. A big magnetic bottle in a small space, as it were. So the ship makes an FTL transit and changes FTL drive to storage mode. The drop in power requirements allow for diverting power to linear accelerators. Antimatter production commences. Magnetic confinement is established to hold the antimatter contents inside the cubic antimatter box that internally is a hypercube. This should allow you to run up the metric prefixes a bit as you should be able to hit exa, zetta or yotta joule scales on storage easily. However the whole idea is predicated on the notion that if an FTL drive can "warp" space so that FTL travel is possible; that it should also be possible to make the same effect on a much smaller field and with lower power requirements so that a large scale anti matter battery is feasible. [Answer] I notice you've already got plenty of answers about capacitors and batteries. But since we're in space, what about speed? ## Speed matters, and in space, speed differences can be astronomical. In the mid-60s during the ramp-up of NASA's Apollo program, there was a lot of research being done on the Moon. And a lot was still unknown: what was the surface really like? Was it rocky and hard, or was it so soft & dusty that a lander's legs would sink right in? Geologists at the time were arguing about the [origin of the Moon's craters.](https://en.wikipedia.org/wiki/Lunar_craters#History) There were two competing theories, that they were formed by meteor impacts, or that they were formed by volcanic eruptions blasting holes in the surface. Volcanists argued that when you look closely at the Moon's surface, nearly every single crater is perfectly round. In fact, it's hard to find one that's not. [![Close up of The Moon's craters](https://i.stack.imgur.com/Djr4u.jpg)](https://i.stack.imgur.com/Djr4u.jpg) So how could it be that in the chaos of space, with meteors being flung about at all different angles, that all the craters are perfectly round? There's not a single elliptical or elongated crater shape to be found. To learn more we had to study impact craters, and meteors sometimes hit Earth too. Like [Meteor Crater](https://en.wikipedia.org/wiki/Meteor_Crater) in Arizona. Originally this was also thought to be caused by a volcanic explosion, a fair point since the San Francisco volcanic field is only about 40 miles away. However, meteorite fragments had been found around the rim and basin of the crater, and the theory was proposed that this was a real meteor impact site. This led [Daniel Barringer](https://en.wikipedia.org/wiki/Meteor_Crater#Grove_Karl_Gilbert) on a business venture: a crater this size (>1km across) must be caused by an equally huge meteor filled with precious metals, right? [![Meteor Crater in Arizona](https://i.stack.imgur.com/aYJkd.jpg)](https://i.stack.imgur.com/aYJkd.jpg) So in 1903 Barringer's mining company, the Standard Iron Company, purchased the land with the idea that due to ~30 tons of iron meteorite fragments laying about the basin, the meteor itself must be buried somewhere under the crater floor. Barringer spent 27 years searching, but no significant iron deposits were ever found. Where was the giant meteor? It would take several decades before science matured enough to answer. # $E=mc^2$ or, the equivalence of mass and energy Einstein to the rescue! This equation may be so familiar to most people by now that it's jaw-dropping, awe-inspiring everyday significance must be lost on you. But take another moment right now to really let it soak in. This mind-bogglingly simple equation is telling us that energy and mass are equivalent. To put it another way, mass is energy. (And energy has mass. If you stretched out a rubber band, and somehow were able to weigh it like that, the rubber band would weigh more while stretched out than it would at rest.) ## Speed is also energy And in space with nothing to slow you down, objects can get thrown around at scary-fast speeds, right? Speeds so fast we usually measure them in km/s, or kilometers per second. So what happens when a meteor already traveling at several dozen km/s gets pulled in even faster by the Moon's gravity? It literally explodes. To put it in technical terms, the impact force is so great it breaks apart the bonds of the atoms holding the meteor together, and all that mass gets converted to energy. Take a look at the Moon's craters again. Yes, they're all perfectly round, but that's because each time an impactor hit, it exploded like TNT. The Moon is showing scars of literal bombardment. Why did Daniel Barringer never find his giant meteorite? Because we wouldn't discover until later that when a meteor hits at high speed, it hits with so much force that most of its mass vaporizes into energy. # Kinetic kill weapons The irony of weapons in space is that in space everything is a weapon. If you have the capability to get up to orbital speed, or even faster, your vehicle itself is a weapon. If you could for example, approach the speed of light, your vehicle could easily destroy an entire planet. You don't need bombs or warheads, any regular matter like debris or asteroids will do. It's worth mentioning that the [Chinese have already done tests like this](https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_missile_test) on their own satellites. No warhead required, just a big, pointy steel rod, AKA a "kinetic kill vehicle". (Also worth noting that this test in particular did not vaporize everything, it actually scattered large pieces of debris everywhere much to the dislike of every nation with a space agency.) ## The rule of cool To answer your question, it doesn't really matter if capacitors explode when being shot at, because everything explodes if it's going fast enough! (As long as it has mass, i.e. a projectile, not a laser weapon) Use this to your advantage when designing, or ignore it if it's not. If this is for a game most people won't notice anyways. The reality is even tiny micro-meteorites can turn into bombs if you're traveling fast through space, leaving Moon-like craters in the hull of your ship. (You'd need auto-targeting lasers or something to handle micro-meteorites and debris while traveling fast through interstellar space.) I hope this answer was helpful and added some things you haven't considered yet. Cheers! [Answer] Based on today's known science, the most efficient future technology for storing energy is superconductors. Basically, you trap energy in the circuit, with current endlessly turning around in it. This should allow much higher energy density than chemical batteries, and very fast charge time. There are two main limits with it. One, you can only put so much energy into it before it stops superconducting. Two, the more energy you put in it, the more the circuit will try to expand, meaning that you have to brace your superconductor ring to prevent bursting. When a superconductor ring is compromised (by the above, or because someone shot at your ship and put a hole in it) and it stops being superconductive, you now have a very strong current flowing through a not-that-conductive circuit, and the energy of said current starts being transformed into heat. At those levels, it is less like "electrical heat radiator" and more like "massive explosion with bits flying around very fast". Which may very well compromise nearby rings, causing a chain reaction, unless you put them very far away and shielded them from damage. So the result would be ships spectacularly blowing up when their superconductive batteries are damaged. A much more far-fetched but still not-forbidden-by-physics option (think cold fusion) is nuclear batteries, where atomic nucleus absorb gamma rays and stay in an excited state for a long time - decades for, say, Hafnium. If you could somehow goad those nuclei to release gamma ray at will, say by bathing it with the right X-ray frequency, you would get a nuclear battery of immense energy density. The problem is, no-one actually has an idea how you're supposed to do that. But hey, future-tech. This would be much less exciting, as it would mostly act as a boring, mildly toxic heavy metal. If you want safer ships for your story, it may be a good option. [Answer] Other answers point out that sudden capacitor discharge & other failures would be pretty catastrophic. However, I think the biggest risk would be excess heat generated in normal operation making the ship too hot for crew to survive. Massive banks of capacitors/batteries based on existing tech would add a huge amount of weight, take up lots of space, & generate insane heat levels, all without adding any concrete advantage. Converting thermal/kinetic energy from fusion to electricity always loses some energy as heat. Same for converting electrical energy to kinetic energy. Batteries & capacitors based on existing technology are not competitive with fusion for capacity to store energy. They have no way to be safer or more efficient at storing energy than leaving it as unreacted fusion fuel, so the battery premise doesn't make sense. If you want something with the FTL that requires building up power reserves (with associated risks), I think you can do better than the capacitor idea. Consider going with a FTL drive that inherently requires a buildup of power (maybe a disc of unobtanium that has to be sped up until its edge reaches 0.999C, for instance?) [Answer] Since you tagged this with [science-based](/questions/tagged/science-based "show questions tagged 'science-based'"), let's consider one of the reasons we don't put a heck of a lot of batteries parallel of each other in the real world: ## [Short circuit current](https://en.wikipedia.org/wiki/Short_circuit#Damage) The capacity of a battery bank (in Ah) goes up linearly by each battery you place. 2 batteries is 2 times the capacity of 1. 400 batteries is 400 times the capacity of 1. The short circuit current follows the same rule. If a battery holds 100 Ah, discharging it at a rate of 1 C pulls 100 A from it for one hour. Discharging it twice as fast (200A/h, 2 C) can only be sustained for half an hour. The higher the C, the higher your discharge speed, the shorter it can sustain this power. The maximum safe discharge rate of a battery is, depending on it's type, usually between 1 and 5 C. A short circuit is only limited by the impedance of the battery itself, the object causing the short circuit and the wires connecting the battery with the object (if any). Let's throw in a couple of estimates to get a feel for what you're trying to do: A modern, fully charged battery of an Electric Vehicle has a voltage of around 400 Vdc and a capacity of at least 100 Ah (40 kWh). That's slightly more than for example that of a BMW i3. The short circuit current of such a battery is at least 500 Ah. Now, I don't know how much power your FTL and weapons are going to require, but probably more than one battery can produce. Let's use another example. The power usage of a the Enterprise-D could be [at least 12.75 billion gigawatts](https://scifi.stackexchange.com/a/99181). The exact numbers don't matter and it was a fairly large ship, but let's say at least 1 TWh is required for emergency actions. You'll probably need a lot more. That's 25,000,000 batteries already. The short circuit current of something that powerful should be enough to vaporize your ship. --- Long story short: if you do this, make sure you have measures in place to protect your batteries and their power distribution. [Answer] You could go the other way, and design it so it provides more protection than risks. Using a multi cell battery banks as a protective covering over the hull with the ability to switch out damaged sections means the weight of the batteries is doing two jobs - one for whatever battery storage you need and two to provide radiation and physical protection. I think I read somewhere that one of the U-boat models used that principle and where harder to kill because of it, but I can't find a reference with my quick google search. Note I am referring to batteries which arn't a big risk when physically damaged, ie where the energy release takes some time like lead acid, rather than those that can discharge very quickly. Likewise capacitors would normally be only charged when impulse power (say a phasor style weapon) required it. [Answer] # FIRE First, a bit of backstory: UPS Airlines Flight 6 was a 747 traveling from a city in Germany to Dubai. There were no passengers (as it was a shipment flight, as is all the flights under UPS Airlines..), except the two pilots. At 14:53 UTC, UPS Flight 6 departed from Dubai International. At 15:15, the a warning for fire appeared on the plane's EICAS display. The pilots were roughly 138 miles away from Dubai International. The fire had destroyed the connections from the controls to the elevators. Thick smoke rapidly filled the cockpit. At one point, captain Douglas Lampe's oxygen mask failed. He went to get the emergency reserve oxygen supply (EROS) but fell unconscious before reaching it. This left Matthew Bell to control the plane. Bell attempted to land at Dubai again, but was too high and passed over the airport. He then attempted to land at Sharjah airport, but turned the plane in the wrong direction. Finally, just past 15:42 UTC, the plane crashed in an unpopulated. The culprit? Lithium batteries. UPS Flight 6 was carrying some 81,000 lithium batteries. The batteries caught fire through autoignition (as stated in the NTSB's final report), burned through the flame-resistant cargo lining, and went on to destroy the plane. Lithium batteries (and many other lithium compounds) are very flammable. Battery fires have caused numerous fatal or damaging accidents, and are not easily extinguished via conventional methods. Considering this, batteries that are capable of operating FTL systems would be a massive fire hazard. Once ignited, controlling the fire would be very challenging; this is evidenced by UPS Flight 6, where, despite fire supression systems, the fire still went on to destroy the aircraft. ]
[Question] [ ## So let's consider a species of blind, sea dwelling, squid-like aliens. They are sentient, intelligent and highly social. As their societies develop and their available knowledge increases they require a method of storing information without needing to remember it all. --- These aliens are completely blind as they branched off from a species that lived primarily in caves and the water they live in is actually a murky water-based solution making vision less useful then here on earth. They can however very effectively echolocate, sense nearby electromagnetic disturbances and feel the basic chemical composition of certain objects by touch. Other then the difference mentioned above the body of water they live in is essentially the same as our own seas and oceans. --- Given all this: What different methods of "written" communication would they likely develop over their history (as they develop new technologies and get access to new materials, etc), what would they use to write, write on? I am not asking about the language itself, the syntax, the grammar or anything like that. Simply and literally how they would write. Idealy I'm looking for systems which would enable them to take advantage of their abilities (for example being able to "see" into objects via echolocation). Note: I put "written" purposely in quotation marks to indicate that it can be any form of information storage as long as it is permanent and does not require someone to remember everything. Note 2: As I said in the question, I'd like to know how they'd write at different points of their history, so far I've gotten adequate answers for ancient preindustrial times, but none for when they start mass "printing" or even further when they start using computers, machines, etc... I'd love for example ideas for how their computer's interfaces would work. Only speech? [Answer] Underwater, they would be most easily able (certainly at early stages of technological development) to scratch and pierce objects. If they could develop some form of cordage, they can also tie knots, thread sequences of objects on string (like necklaces), or weave patterns. These could be read by simple physical touch, but also Echolocation: * piercings (like Braille but patterns of holes pierced through rocks or shells), and hard objects threaded on strings would be easy to read by echolocation. Objects that are larger then the wavelength of sound used can be picked out clearly. * An added benefit would be that stacks of pierced plates or layers of beadwork would be readable; in essence you could read several pages of a book without opening it since sound passes through soft objects and reflects off the harder ones. Sense nearby electromagnetic disturbances: * The above two solutions would allow this if the hard material had electrical properties different to the water. They'd be able to read the pattern The chemical composition sense seems less useful to me, especially at a lower technology level. If the chemical is detectable then it must also be dispersible and would disappear over time. It doesn't seem a good choice for long term storage of information. Edit: For more technologically advanced stages of their history Piercing writing would seems to be more amenable to technological development than knots or beading As technology progressed, this would easily lend itself to a printing press analogue and a typewriter analogue, assuming that they develop a paper-analogue (should be possible). Computer input systems could function in whatever way typewriters do of course, and the display could be like one of these: [![enter image description here](https://i.stack.imgur.com/Ij9tZ.jpg)](https://i.stack.imgur.com/Ij9tZ.jpg) Pins extend out or retract in to make the piercing letter patterns or images, and the echolocation sense can view them. [Answer] I'd like to introduce you to [this question](https://worldbuilding.stackexchange.com/questions/59791/what-could-an-aquatic-civilization-use-to-write-on-with/59805#59805), which, while it doesn't focus on the blind aspect, does ask about underwater methods of writing. Culling that, there's my answer: > > I have been pondering your question and finally came up with a way to make fabric and thread: <http://marinelife.about.com/od/glossary/g/byssalthread.htm> > This stuff is made from the fibers mussels use to attach to things. There would have to be an abundance of them in order to make as much as would be needed for writing. > The other way that writing would most commonly happen would have to be via carving--using rock and coral. > > > And there was more than one answer talking about raised scarification tattoos, string knot systems of writing and of course, carving into stone or coral. Basically, anything that can be felt rather than seen would be where you would go with this. Not so basic: sound. Objects placed and carved could, in fact tell a story, like a recording, if hit by the correct sound, which you could record in the rock with some kind of braille-like bumps--the creatures would make the sound indicated, and part of the "recording" would echo along the specifically placed stones or underwater structures. I would think that they would get more and more complex with it--experimenting with it in ways we haven't even thought of. [Answer] Method 1- etching These creatures being tool users, could effectively create symbols representing different echolocation patterns. These symbols could then be etched into rocks or if they are significantly advanced, metal objects. These etchings could then be felt or depending on the level of their echolocation viewed by the other members of the society. Method 2- chemical imprinting As you stated, they can: feel the basic chemical composition of certain objects by touch. They, being scientifically advanced, could coat surfaces in differing patterns of chemicals representing different echolocation patterns. These chemicals would have to be waterproof though (obviously) I think this to be the better option due to their technological advancement. Basically they would use chemicals like we use letters. [Answer] # Use Memory Sponges [![enter image description here](https://i.stack.imgur.com/fLY0A.jpg)](https://i.stack.imgur.com/fLY0A.jpg) These things are colonies of very small individual animals. You could theoretically use these to store and retrieve information simply by singing to them. The colony remembers those sound waves and play them back upon command. There's no reason why they couldn't remember more than one "song". The fact that they look like brains is a bit of a bonus. [Answer] Flat pages can have “ink” applied that their chemical sence can detect, so it stays flat and does not need an ingraving or braille-like texture. So it would seem like normal writing to us, if there was color contrast we could detect between the ink and the paper. But it’s the same idea really. Signs made to be read from a distance will use 3d inlays, not to create a releif like a carving but rather to have a density difference. Heavy stone letters can be attached to a net backing to make a sign that can be read using the active sonar sense. [Answer] If they are blind, they might evaluate their enviroment by a combination of echo-location (for living and non living objects) and electromagnetic location (for living objects which use muscles to move). Early stage of development. Echo-location will work well in their early stage of technological development: they can harvest stones, break them to suitable sizes and cluster them on a surface in a mutually agreed alphabet. They would then "read" the stones by using their echo-locator. They would need periodi cleaning, as debris falling on the surface may, over long time, prevent echo-reading. Intermediate stage of development They have learned how to shape surfaces, so they can carve surface to show features that they can read via echolocation. This enables them to carry around the written media and loosen the bond with the surface where the stones were laid. It also makes cleaning easier. Later stage of development In a later stage of their development, once they have developed the ability of controlling electromagnetism, they can engineer surfaces to emit coded pulses, that their EM locator will catch and decode. This will require less "cleaning" maintenance but will make them dependent on power sources to keep the device fed. [Answer] You haven't said whether the watery medium contains dissolved solids as does seawater. If the water were rich in tannin, for example, it could have very low light transmission, but would otherwise support familiar life functions. So-called 'blackwater' rivers in Florida are practically opaque, but not silty. 'Murky' water generated by high suspended silt content isn't really consistent with an underground cavern because the silt will settle out. One presumes that they depend on a sonar-like sense like river dolphins (now almost extinct--sadly), which live in murky water and are have vestigal eyes. However, water, being a powerful solvent, will corrode organic material and most metals. So if this blind species needs durable records, they will need to engrave them on a suitable mineral. Carbonate (HCO3) plates could work. The written language could engraved--by lowering pH selectively--or precipitated by raising pH. Perhaps, the written language could be an adaptation of an innate evolutionary capability of the species. If their evolutionary ancestors were able to form tooth- or shell-like structures, the sentient species could adapt this by making more elaborate 3-D structures that they could 'read' with a sonar like sense. (Dolphins can 'see' inside your body & count the coins in your pocket.) [Answer] Let's start with a few assumptions: they have tentacles, they are capable of using multiple tentacles in conjunction for human-equivalent or greater manual dexterity, and at least a few tentacles have a superb sense of touch. Early History My instinct is to say "engraving," but that's hard to do underwater. You can't swing a hammer well, so chiseling is right out, and anything soft enough to be marked with a stylus will be washed away by the water surrounding it. I'd suggest something along the lines of knotted strings in particular patterns. A long rope with a string dangling off in a particular pattern of knots for each letter or word would make the most sense. If you want to take it a step further, that written language can come about from squids communicating with each other by expanding knots of muscle in their tentacles and allowing others to feel. Knot writing won't be the most compact method of information storage, but they're blind and underwater - they already have problems. Echolocation just doesn't work - vision only works for information transfer because we can discern color, and they won't be able to. Imagine trying to read something written in black on a sheet of black paper and you'll get the idea - sure, you can TECHNICALLY see the dents in the paper, but it's hard. Now imagine that with sound. Medieval Probably going to stay with knot-writing. However, if you're willing to stretch the biology of the world a bit, you could create a species of flat coral or sponge that goes rock-hard upon death, but is soft and markable beforehand. Or maybe it's a soft waxy clay that hardens upon exposure to a deep-sea smoker's gas, or to some other animal's products. The point is, either they're staying with knot-writing and touch, or they begin writing on soft things that harden once written. Industrial I'm going to assume that you've already figured out how to propel them into the industrial age when any furnace would heat the water around it too much for any smith, and just leave that be. Their techniques will probably be the same - maybe they can now make some artificial tablets rather than just harvesting them, but the principles will remain. Electronic Again, I'm going to assume they've gotten around the problems associated with water and electricity in our world. The solution is probably auditory - a computer that works by touch will be bulky, to say the least. Early computers will probably use "knotted" (hole-punched) "ropes" (strips of waterproof "paper") rather than punch cards, because a few squids remember it and it worked THEN just fine. Later ones will probably just get more and more sophisticated auditory output. [Answer] While the obvious answer would be a brail equivalent for the pre-ancient period possibly using holes or stones to count and identify items (which is what our earliest forms of writing did), I have a serious issues with the whole idea they would develop any form of visible writing at all if they were blind. I would be more likely to think their transferable methods of communications which would happen in their ancient periods and on would be more likely related to their echolocation, tactile sense of chemical composition, electromagnetic sense. With echolocation we think of it as painting pictures in the mind but maybe it could also be used to paint pictures in the mind of others such as a keeper of knowledge who could then echo data on to someone else. Once the requirement for it to be stored on some type of transferable media their society should be developed to the point they are looking at themselves and the world around them for the type of stabilized media we found first in papyrus, later in paper and now in the electronic products we now use for data storage. I cannot imagine what sort of plants or animals in their world they would use but basically they would probably be using sand with some sort of binder to begin with like we did clay tablets but instead of using a stylus of some sort to write with maybe they would be able to use their echo location and sound waves to "paint" what they needed on the smooth sandy surface of the underwater world they inhabited and then whatever binder they found to make it semi permanent or permanent. Using their tactile sense of chemicals could be used to create a chemical picture of their information in the sand as well. Even better yet if their echolocation can differentiate between chemicals as well. I don't necessarily see the use of magnetism until their later periods of development because they would be much harder to move around in the environment than the first two. By then their society should be to the point where they are developing methods of studying and reproducing magnetism though. To do that though it seems they would have had to have developed methods to survive on land at least some of the time at least in suits if not in some amphibian state. I cannot see how they can explore their solar system if they can't get out of the water. --- On the other hand there may be some aquatic individual out there at the moment saying they cannot see how a land animal could possibly launch a rocket ship off dry land. Adapting to and figuring out how to do things in our own environment has to be a must for any sentient species. Figuring out how another sentient species adapts to their different environment to get things done takes a lot more thought. [![enter image description here](https://i.stack.imgur.com/17vCX.jpg)](https://i.stack.imgur.com/17vCX.jpg) [Answer] For semi permanent, chemicals would work but they would likely dissolve away over time. Early writing may involve placing items in specific patterns. This is pretty temporary since it is easy to disrupt this. Making scratches in a solid surface is much more permanent if their sense of touch is acute enough. Unlike carving, you don't have to swing anything against the water to make an impact. All you need is something to hold onto for leverage. Another possibility would be using a chemical to change the texture of a surface. So the smooth polymer (or whatever) pattern on the rock would be the writing. If you can alter the texture of the polymer, you can encode more information in the same area. You could also change the chemical composition to, for example, add emotional impact to the writing. [Answer] Edison scratched audio into wax. These became the vinyl records we still have today. Squid have sharp beaks. Your squid could make recordings just like Thomas Edison. They would swim along a rock with their beak scratching the rock while they sing/talk. To playback the recording, a squid would silently swim along the scratch with their beaks in the scratch like a needle on a record player picking up the vibrations. (think bone conduction like Beethoven biting pianos to hear them) ]
[Question] [ In the Metro series of video games, there exist various pneumatic weapons, essentially air-powered rifles. It seems like these weapons are supposed to be easier to produce/maintain in a post-apocalyptic setting, as they use air and ball bearings instead of bullets. They also seem to be more silent than traditional firearms. What I'm wondering, though, is if this is realistic. Is it possible to create an air-powered rifle of a similar size/weight to a normal rifle, that can fire with deadly force? Can such a rifle be semi- or even fully automatic? I know there exist things like airsoft rifles that fulfill most of these criteria, but as they are not designed to be deadly I wonder if that is an insurmountable limitation. It's also possible there are other problems I have not considered; if so I would like to know about them. If deadly air rifles are possible, I am wondering why no one seems to be using them. [Answer] Yes, such a gun is absolutely possible, but I'm not sure if it would actually be used in your scenario. Air rifles were not only real, but deadly. As another poster mentioned, the [Girandoni air rifle](https://en.wikipedia.org/wiki/Girandoni_air_rifle) was a weapon used by Austrian forces during the Napoleonic Wars; Napoleon so despised the gun, considering it an assassin's weapon, that any soldier captured with one was to be executed as a spy and not treated as a prisoner of war. The Girandoni had its flaws, leading to it being dropped from the armed forces of Austria, but it wasn't discontinued for anything to do with its lethality. It was, in fact, far deadlier than any musket of the time; more range (up to around 125 yards on a full air reservoir) and being a rifle was more accurate at range as well. It was also silent and smokeless, so firing the thing would not betray one's position: a very useful aspect when considering flanking strikes, ambushes, etc. And perhaps most importantly, it was a repeating weapon; muskets had to reload after every shot and got three to four shots a minute (normal rifles were harder to load and had perhaps half the firing rate), but the Girandoni could fire every few seconds out of a 20-shot magazine, and a full air reservoir was good for about 30 shots before pressure dropped too far to be useful. For the downsides: the air reservoirs were expensive and difficult to craft with available techniques and as such were never in adequate supply, and were delicate: one crack rendered them worthless. They could be refilled in the field in theory, but that took a preposterous amount of hand pumping (or a wagon-operated pump) to accomplish. Intensive training was required to use the airguns properly. Basically, they were too expensive for mass production and too delicate for rough use on the battlefield; fine for well-trained elite forces, but not for the general soldier. The problem here is that the downsides are exactly what you need to be strengths to make it a viable weapon in a post-apocalyptic environment; "Powerful but delicate and expensive" is a very bad fit, at first glance. If, however, you were writing in an environment that still possessed precision manufacturing techniques and effective air pumps but lacked certain critical supplies, specifically gunpowder, airguns would probably become the dominant ranged weapon. In short, you need an environment with access to at least Industrial Revolution-era technology, yet where gunpowder is too rare or difficult to obtain/produce for general use, if you want to run with this idea. That's a fairly tall order, but with enough ingenuity you can probably set up such a world. [Answer] ## Yes [![enter image description here](https://i.stack.imgur.com/2zQzY.png)](https://i.stack.imgur.com/2zQzY.png) The [Air gun](https://en.wikipedia.org/wiki/Air_gun) was a pressurized gun created in the early 19th century, its modern day counterpart is a BB gun, but that's because gunpowder guns are just more effective. If for some reason, gunpowder guns are not feasible, the it is safe to assume that the air rifle would evolve along a more lethal path. Nobody uses them because, simply put, gunpowder is easier for gun making. [Answer] Is it possible? Well, given that [they were used in real warfare](https://en.wikipedia.org/wiki/Air_gun#History), I would say that they are possible. Of course, as the article explains, as every other pneumatic system (specially if it works with gases), keeping the chambers sealed was a critical point, making them weapons that are both difficult to produce and to maintain (specially given the improvements in gunpowder rifles). Nowadays, making them automatic should not be very complicated in theory, all you need is something that keeps providing gas at high pressure. The problem is that the available means (compressed gas canisters or a pump with a motor) are not practical when you compare them with regular, gunpowder automatic weapon. Nowadays, the most close relatives would be the [captive bolt guns](https://en.wikipedia.org/wiki/Captive_bolt_pistol) used in slaughterhouses to stun animals. You could have seen one of those in action in "Fear the Walking Dead" (where they "rekill" dead patients to avoid them becoming zombies") and in "No country for old men". [Answer] Lethal air rifles have existed in the past and could certainly be made more reliable and effective with modern technology and industrial processes. Around 1780, the [Girandoni air rifle](https://en.wikipedia.org/wiki/Girandoni_air_rifle) saw service with the armies of Austria. Famously, one such weapon was brought on Lewis & Clark's expedition to the Pacific Northwest. It had several advantages over blackpowder weapons, but also some significant disadvantages that led to it being removed from military service. As I recall, Sherlock Holmes feared that Sebastian Moran, the chief henchman of his archfoe Professor Moriarty, was hunting him with an air rifle. [Answer] They exist today. There are air guns used in small and big game hunting. This company sells air rifle that can fire a .45 cal projectile from 900fps to 1500fps. Check [Air Gun Depot](https://www.airgundepot.com/large-pest-hunting-air-rifles.html). For example this gun actually is a double barrel .50 cal air gun that shoots each projectile out at 1130fps. [Seneca Double Shot .50 cal Air Gun](https://i.stack.imgur.com/KUfmD.jpg) And this was just a quick web search for air guns that are capable of hunting large game. I would probably bet you could find airguns set the fire such a deadly projectiles such as 30 cal outwards of 2000fps. EDIT: below is an image of the US Air Force is air gun that can shoot a 30 caliber projectile from 1000fps to 1300fps, depending on whether you get the long barrel or the carbine. Pictured below is the long barrel version which is also available in 45 caliber and it shoots that at 930fps. [![AirForce Texan SS[3]](https://i.stack.imgur.com/yruV7.jpg) Here is part of the description of this rifle: > > The US AirForce Texan made headlines throughout the firearm industry when upon release it was billed the world's most powerful production air rifle. The Texan turned heads then, and AirForce building upon that success with the AirForce Texan SS big bore air rifle! > > > [Answer] It depends on the type of air gun, if it a single shot spring powered air gun, than easily. Because they have a vertu simple mechanism and so would be easy to maintain, are reliable, and on the most part silent, so long as the gun does not shoot at super sonic speeds. Disadvantage over conventional fire arms is that they spit slower, and require more movement to operate, they are hard to operate while prone. Also they cam have problems with accuracy of nor proteolytic made. Multi shot air rifles are more difficult to maintain than a bolt action rifle, or an ak-47 [Answer] At first : The other answers already showed the existance of such a deadly weapon, mentioning the Girandoni. I would like to write about the disadvantages. I think that you should take armor into account. Finding armor that is strong enough to protect you from being killed by a bullet fired from an airgun is far easier than finding armor to protect yourself from a firearm. Also, in fights involving masses of people, a firearm is very likely more useful;modern assault rifles could fire bullets piercing through up to 3(?) people - your airgun would very likely only kill at most(as it's not very lethal from what I found, see below) one per shot. Furthermore, I consider regular bullets to be far more devastating; what if you would hit your enemy at - let's say - the knee ? The hit by the airgun wouldn't pose a big problem; but when shooting somebody's knee with the power of firearm, he would very likely not be able to walk anymore. From Wikipedia ["Projectiles"](https://en.wikipedia.org/wiki/Projectile "Projectiles") : Projectile energy air gun : 11,000 to 29,800(air rifle, for example Girandoni) Projectile energy firearm : 58,000(pistol) to 470,000(AR) all values in J/kg This means, a lightweight easy to use pistol has about twice the energy of a 4kg Girandoni. And an AR even got about 16 times(!) the firepower. And from this [article](https://www.sciencealert.com/game-of-thrones-exposed-the-science-of-skull-crushing) : > > 2,300 newtons of force would be needed to crush a human skull > > > So let's suppose the stop distance of the projectile is 6,5 mm(average male skull thickness). We calculate F = KE ÷ 0.65 centimeters, where KE is one of the values mentioned above. So for our Girandoni : 45846,15 J/cm are 458,46 Newton And for the ARs : 458,46\16=7335,36 Newton So as a rough estimation : The AR could crush more than one skull, while our air rifle cannot* Herein, take the skull only as an example. Think of somebody protection himself with thin steel plates. An AR could pierce, while your Girandoni would struggle. Concerning weight, the Girandoni which has been previously mentioned is quite similar like a typical AR(M-16 is even less heavy). In this point, pistols are better. The only advantage I see for air rifles is stealth. As mentioned in other answers, they are much harder to spot than conventional firearms. And if - in your post-apocalyptic world - still some remainders of society exist, like forensics or police, they may draw many conclusions from an advanced ballistic research - such a thing isn't really possible when you use an air rifle. So in the conclusion, a firearm is reasonable if you have only a few poorly armored enemies and are good at aiming. [Answer] Plausibility of deadly air rifles. Well, I'm not an expert, not even an initiate on hand guns and rifles, but when I was younger I went to summer camps with an organization similar to the scouts or the YMCA, and I remember that one of the activities done once every summer was shooting with carbines. They were pneumatic guns that looked like this: [![Carbine](https://i.stack.imgur.com/9rPUm.png)](https://i.stack.imgur.com/9rPUm.png) Image from Google And the way of reloading was putting the shoulderpad on your knee, hold hard on the end of the rubbery/wooden part and with the other hand push hard away and down the tip of the barrel. Then the barrel hinged down while (I guess) compressing a load of air. Then you could see down the open barrel, you where supposed to put a lead pellet in the barrel and then close the carbine back until you heard the carbin made a CLICK sound. Then you shot. I think that this gun is deadly if aimed at people. Usually we shot at pellet catchers A friend once bought one (pneumatic carbine) and used whatever he found for his targets (beer cans, coke cans, mostly cans) (yes, he used the gun with proper protection, behind the things he shot was always a reinforced concrete wall. It was a basement). I remember that he tried to shoot once at a plastic bottle full of air, and the pellet ricocheted off the bottle. He tried to shoot again but with the bottle full of water and this time around the pellet made the expected hole on the bottle. I didn't know that that could happen. ]
[Question] [ In a story I'm working on, there are some creatures that eat hair, wool, fur, and anything similar. They're not mites or insects, but are (very roughly) the size of humans. Is there any realistic reason that a creature would need to eat hair? [Answer] The creature evolved from a carnivore (or omnivore) and it's ancestor was a messy eater. Food was scarce, too, so they developed to be able to make use of the hair they digested. Over time, The ability to produce Keratin on their own has disappearead (which should be biologically feasible since with the keratin from their prey this would not be a disadvantage), so now, to have their hair, nails or claws, maybe scales, grow, they depend on an external keratin source. It might even be that the amount of keratin they digested determined the amount / strength / texture of their own hair, thus influencing their attractivity to the other sex. [Answer] These creatures evolved in a symbiotic relationship with a larger creature with fast growing hair. If the Fuzzie's hair was allowed to grow unchecked, the poor things would soon become unable to move, but they need lots of hair because the climate is very cold. Our Eaters would groom/consume the creatures hair as they slept, and in exchange were allowed to live in the Fuzzie's cozy burrows. [Answer] Well this is a very scientific and tough explaination. But stay with me: Assuming they are human-like if they grind the hair very well with their teeth they would get a dust with a quite large surface. The dust contains mostly keratine which - in combination with a strong acid (as in a stomache) forms tyrosine and decarboxylase. The large surface helps speeding up the process enough so it hasn't passed the whole digestive tract before everything is done. Tyrosine combined with the enzyme tyrosine 3-monooxygenase (which is formed in the brain or - more relevant in the adrenal glands and also found in the stomache) becomes L-3,4-dihydroxyphenylalanine which in combination with the formerly mentioned decarboxylase becomes dopamine. Well-grinded in the beginning it should be possible to speed the whole process up enough to create dopamine early enough to absorb it in the colon. Within a reasonable amount of time it will travel to the brain. SO what's the point? Well, several neurological conditions, most famously including Parkinson's disease have shown to result from a lack of dopamine-secreting neurons in the midbrain area called the substantia nigra. Eating hair would not cure Parkinson's disease or other neurological conditions, but it would help supress the syndroms. And it makes happy (Yes, raising the dopamine-levels in your body would get you stoned). So why don't people do it? You can easily have the body create more dopamine by injecting adrenaline or taking amphetamines or many other ways. So people get stoned on dopamine, but use less discusting ways then eating hair. [Answer] Far, far in the future, many animals have developed a mechanism against predators. There are deadly toxins in their bodies, flowing around in vein-like structures. Their hair, however, is like present day hair, made of keratin. The only part of an animal that one could safely eat would be the hair. Such an animal would also have to eat plants, so that it gets enough nutrients and calories. [Answer] Use the hair of the animal/person as an important digestive additive and set them as a predatory carnivore. Large predatory cats are healthier when they eat the hair of the animal that capture. This could be used by your carnivore to ensure a healthy diet (and prevent watery poop). [There was a study done to prove the digestive benefits of the "roughage" from fur](http://healthypets.mercola.com/sites/healthypets/archive/2012/11/19/dietary-fiber.aspx), and the results came back that even when given beef with added nutrients and vitamins, the cats who ate the animals with the hair ended up healthier overall. [Answer] This wouldn't be as a source of nutrition, but the hair could be routed outside of traditional digestion and into some kind of storage, and the creature could projectile-vomit hairballs as a defence mechanism. ]
[Question] [ You have a spaceship, covered in steel armor. The enemy is shooting a laser at you in pulses intense enough to vaporize the steel. But you have a brilliant idea: float a big glass lens in front of your ship, positioned so it will bend the laser slightly to the side so it misses your ship. In theory, if the lens is transparent enough, it should let the vast majority of the energy pass straight through it without heating up the glass too much. Could this work? Or would the laser always destroy your lens more easily than an equal mass of steel? [Answer] I used to work with high-power pulsed lasers. There is a limit to how much power you can stick through a lens. Beyond a certain power density, the refractive index depends on the power, and a flat wavefront will focus itself into lines, which ends up breaking the glass. The same might happen for your lens. However, that isn't the real answer. The laser that is attacking you may be made of lenses. Unless they have a one-shot weapon, those lenses survived, and yours could too. The real answer is that lasers are a kinda shit space weapon. A high-power laser is a massive piece of kit. It is hard to get more than a few percent of your energy into the beam. And a nice, shiny mirror (which could be a really light, thin sheet of aluminium on a plastic film less than a micron thick) could reflect a lot. It would also hide your ship from being seen, as most of the time it would be showing a reflection of more space. If the beam is too powerful for this mirror, it will be vaporised, but the resulting plasma will be opaque to most light. If your craft is rotating (as it might to generate artificial gravity) it would be hard to hit it in the same spot. Space is big, so any laser beam will spread out a bit. The [Apollo laser rangefinder experiment](https://www.nasa.gov/missions/laser-beams-reflected-between-earth-and-moon-boost-science/) managed to land one photon in 25 million on the mirror, and even less got back. Most of that loss was from beam distortion by the Earth's atmosphere, but there is still something like a 10:1 loss on the way back just from the optic finesse. This is not to say you cannot use a laser as a weapon. But in the battle between a massive laser and a soap-bubble thin mirror, the mirror has all the odds. The attacking ship has an engine that chucks matter out of the back to make the ship go forward. It can also be a weapon that fires matter at other ships. A lump of something doesn't spread out like light does, and at typical space encounter speeds it will get though most defences. [Answer] Frame challenge In a setting I'm working on, space battleships go up against aliens who use lasers religiously. To combat their effectiveness, human ships employ a long & narrow cone-like structure made of strong tensile material as a shield. Imagine taking a pencil and shaving it into a cone without reducing length. That's the sort of aspect of these structures. The upshot of doing this is two-fold: * incident laser light is spread over a much greater surface area. * narrow-angle effects cause much of the incident light to bounce off harmlessly due to fresnel reflection. As long as the shield tip is pointed directly at the enemy, you can avoid >90% of the beam energy this way. You can further reduce it by making the circular base of the cone star-shaped, increasing the presented surface area (as opposed to the cross-sectional area). [Answer] "transparent enough" is not enough. With a transmittance of 99.9%, your lens would absorb 0.1% of the light hitting it. When you are talking about power fluxes of several kW or even MW, like those involved with a laser capable of vaporizing steel, even that 0.1% is enough to damage the lens and make your defense system moot. In real life system where intense light goes through lenses (e.g. lithography scanners for IC production), those lenses need to be cooled to prevent them from overheating due to the absorbed light, and they use nowhere close to the power flux used in weapons. [Answer] # Mist (frame challenge) Instead of using precious resources for perfect lenses that are fragile to so many other things, why not just dump a cheap gas or other particles in front of the predicted targets? You can even envelop a whole side of the ship in danger. Either by blocking or by dispersing the beam it will reduce or prevent damage. It isn't a passive solution, but waste to disperse can come from anywhere. Excrement of the crew or dust from meteorites, the supply should be easy in most cases. It is also more easy to leave behind in a pinch, while mirrors are harder to collect again or produce again. [Answer] ## Can a laser make for an effective space weapon to begin with? First I will address some of the frame challenges that say a laser makes for a useless space weapon to begin with, since that seems to be a major point of contention. Depending on what technology you put in your setting, this could either be true or false; so, first, let's design a setting where lasers are a threat worth trying to counter. While lasers do spread out some in space, they will still likely be the best option for long ranged attacks in most near-future settings. No, they will not hit something from several light seconds away, but that is not necessary. It just needs to out perform your kinetic weapon options to be your best option. As one other answer pointed out, a laser that fires at something 360,000km away loses 90% of its energy due to optical limitation... but that also means that anything within about 30,000km is still going to hit with most of it's energy. While some settings assume that space battles will take place in deep space at relativistic speeds and ranges of several light seconds, other more conservative settings posit that battles will only take place in the areas of space directly surrounding targets of importance where ships are required to match speeds enough to become part of the same general reference frame so that they can both make an attempt to "hold the ground" where the planet, space station, etc. that they are fighting over is. When you envision space battles being most fought primarily between planet orbiting fleets, two ships in a low orbit around an Earth size planet can accurately and nearly instantly hit any target it can achieve line-of-sight on meaning that lasers have plenty of range to be a sensible weapon choice. In real life, unguided munitions (cannons, railguns, etc.) become pretty inaccurate at ranges of more than a few km; so, even with computer assisted targeting, minor material imperfections can cause a shell to drift several meters off target after just a few km. So, even if you can fire a shell that can deliver a more powerful, more concentrated strike than a laser, odds are it will not be able to hit anything small enough to matter at ranges of greater than a few hundred km. So, a laser ship could cook a gunship from way beyond its effective combat range. Missiles can theoretically do better, but depending on the tech available in your setting, this may or may not be the case. If ships in your setting can not both accurately and instantly move at relativistic speeds, then this puts a cap on how fast you can make your missiles while still giving them the "reflexes" required to hone in on a target. So while your engine tech may be able to get up to relativistic speeds, it could lack the acceleration to get missiles up to speed fast enough to overwhelm point-defenses. Low Altitude Hypersonic missiles for example are hard to shoot down on Earth only because you have so little time to react from the point when a missile crests over the horizon to the time it makes impact, but in space, the same missile fired from >1,000km away will have no horizon to hide behind on its approach as it builds up speed. This will give computer systems and point defenses plenty of time to identify and respond to the threat. As for suggestions about cheap reflective/refractive armor. There is already a known solution for this. Yes, there are material's out there that can reflect over 99% of light in the visible light spectrum, but there is no material that is super reflective at every possible frequency in the EM spectrum. If you make mil-spec lasers able to adapt thier light frequencies based on the enemy's paint job, you can adjust your attack to be absorbed by your enemy's specific defenses. Also, most super reflective surfaces burn at relatively low temperatures turning them black; so, even a low efficiency on the front-end could potentially turn into a higher efficiency as it starts to burn the target. Adaptive frequencies also allow the laser to find gaps where things that should stop the laser become transparent allowing the beam to go right through smoke screens that block visible light. As for the damage potential of a laser, you do not need to actually do a lot of damage to incapacitate a space ship. Giant sci-fi lasers that cut ships in half causing glorious explosions is totally unnecessary in space. All you need to do is make a hole big enough to vent the atmosphere or cut a small hole in a vital system. A modern 25 kilowatt laser is adequate for burning a hand sized hole into a light armored combat vehicle AFTER passing through a significant amount of atmosphere. Since weight is a major concern in space, it is likely that armoring against a laser significantly more powerful than this would be grossly impractical; so, laser systems no more powerful than already exist that are small enough to fit on a truck will be all the firepower a warship needs. Assuming any sort of future tech, there is no reason you should not be able to manage even much more powerful lasers than this. ### So now that we've established a workable laser META, will your lens idea counter it? Unfortunately, there is no setting in which this would make since. A lens can not bend light without also heating up and absorbing some of the energy of the light passing through it. In school, many of us learned that light passes through a medium, refracting due to photons following some weird orbital or bouncing pattern through the medium, but this has been experimentally and mathematically disproven. Refraction requires light waves to stimulate vibrations in a medium. These vibrations create a wave pattern of constructive and destructive interference that form the apparent change in the speed and direction of light. So, if your medium absorbs no energy, it creates no vibrations and there is no refractive wave pattern... and vibrating atoms are the very definition of heat. That said, a HEL's focusing lens can take a large lens surface perhaps a meter or more across and focus it down to just a few square mm. It is the focusing of energy that allows a laser to project an amount of energy that is low enough not to destroy the focusing lens, but then hit high enough to melt steel. When you focus this energy into another lens of similar quality near the target, it will rapidly heat just the tiny little point that it touches and create a thermal shock that will shatter your attempted refracting lens. There is also the issue of positioning the lens. Lasers fire at the speed of light meaning that you can not know where it will hit until it hits you. This means that your lens would have to be big enough to protect your whole ship, but tough enough that every square millimeter of it can withstand the thermal shock of an HEL laser. ### So what is the best defense against a space laser? If you want to make a good defense against lasers, you want to use [Starlite](https://en.wikipedia.org/wiki/Starlite), or something like it. It is a light weight material that can coat your ship's armor and protect against lasers well in excess of strong enough to melt steel. Starlite based armor will significantly increase the needed power it takes for a laser to put a hole in a ship, but even if this forces you to put your lasers into the megawatt or gigawatt range, the addition of any future tech that would allow interplanetary warships to exist in the first place would inherently make the heat and power concerns of such lasers on a spaceship achievable... so you just need to assume that such armor is thick enough to matter, but the lasers are strong enough to still be useful: whatever that balance may be. Otherwise there will be no laser weapons, and you are back to ships using missiles and cannons anyway. [Answer] Instead of lens, you can just use a mirror at the very slight anlgle to the ray, so that the area of reflection is increased and it works for longer. It will eventually burn through, though. Ideally a moving mirror strip. [Answer] [FrameChallenge] Create a barrier of Superfluid helium-4 between you and the enemy, every shot will heat up the slime which will disperse the heat through its whole surface instantaneously, the more spread it is the more heat it can radiate in a low amount of time, allowing it to absolve more heat, and protect you from more shots. Ideally, you would want to spread it as thinly as possible to maximize surface area to cool it down faster (depending on how fast the enemy ship can shoot their laser without melting their ship). Making a giant Superfluid helium-4 radiator, that could or not absolve all the heat from the laser, or just partial enough for your ship to not have a problem with it, depending on how opaque you want it to be. [Answer] A more general answer, as the question started some debates about the link between refraction and dissipation. Ideally, it seems reasonable to distinguish between refraction and dissipation. But it happens one can not exist without the other. (except maybe for gravitational lens I guess. Even then, I do not guarantee it's not the case, in a twisted way. I would believe some energy goes into the curvature for example) The result is "proved" by the Cramer Koenig relations for the refractive index. Since there is always a non zero imaginary part to any refractive index, there is always dissipation. Now you could look at a thin sheet of metal oriented such that its surface is almost normal to the propagation vector of the laser. 2 remarks: 1. You can't have the same angle from everywhere so it could be attacked from a different angle. 2. If you throw more power than the atomic bounds can handle, no matter the orientation of your reflector it will be destroyed. As mentioned in another answer, the plasma resulting from the blasted metal would provide a good shield, so you better wrap yourself in aluminum foil. [Answer] Another Frame Challenge: CHAFF Lenses, even if practical would need to be propositioned between the emitter and the target to work. The calculations and effort needed to first preposition lenses in right vectors and then adjust those vectors in real time as the location of the emitter and target change would be enormous. However assuming your aware of the frequencies the laser operates at you could perhaps deploy pods containing disbursing clouds of reflective particles in between your ship and the enemy. The downside of this is that as a physical defense it would need to be constantly replenished as the laser burns through previous 'shots' so if the fight goes on for long enough your probably going to run out of chaff canisters before the enemy runs out of laser energy. You'd also have to launch new pods every time your ship changed it's vector relative to the enemy ship (or vice versa) because every particle in the existing chaff cloud will continue along its merry way on the original launch vector independent of your vessel. Unless of course you up the tech and complexity of your launch pods to give them some limited outmaneuvering power of their own, command and control data links and some method (perhaps magnetic fields?) of corralling chaff clouds in a bubble around their pod. And I have no idea if the latter is even physically possible without disrupting the all important 'cloud' effect your trying to achieve in the first place. Just beware IF this system could work (and that's a big if) it buys you some time to either get your own shots off or to try and escape. But the clock is ticking. ]
[Question] [ I grew up watching the Indiana Jones and enjoying the creative death traps and Indy outsmarting them. What what about dragons? So this is for a potential novel dealing with a dragon civilization. The dragons are the standard hexapedal model (four legs, two wings) they are roughly horse sized and capable of flight and breathing fire (think Vietnam era flame thrower as comparison) with more realistic hide (scaly and tough, not the impenetrable armor of myth) and preindustrial tech (black powder weapons and sailing ships) and they have come across an ancient temple with something inside protected by puzzles and traps. But here is where I am curious and need the wisdom of the crowd. See, any trap activated by stepping on the wrong tile is useless if you can just fly over it, as is the standard spiky pit. Even if you make the corridor low to negate that advantage, the dragon might still bypass it by pouncing from the floor-to-wall and then wall-to-floor. Not to mention without some form a fire proofing, one good breath and poof there goes the booby trap. So what kind of primitive booby traps could be made that could incapacitate/kill a dragon? [Answer] Put the trap in a corridor too narrow for the dragon to unfurl its wings. That will negate the advantage of flying. Other possibilities are nets and falling rocks, or spears springing out from the wall -- anything which confines the dragon, or injures it so quickly that its flight is useless. [Answer] ## Nobody likes elevators. Sorry, the stairway is closed for repairs. Please press the button for the floor you want. Otherwise the elevator will fall 20 floors ... release its crushed contents to the acid pit beneath ... close back up again (complete with a Sorcerer's Apprentice mop and broom to clean up, of course) ... and return to its home floor for the next eager adventurer. (You can ask the physics people whether a dragon flying in an elevator can keep it from falling - usually the dragon doesn't like this answer) ## Beaded curtain. Decorative strings of beads separate the rooms of your complex. Some of the beads are adorned with lovely decorative jewels in the shape of a scarab. What could possibly go wrong? ## Snakes. Don't you love snakes? I don't really understand who feeds the poisonous snakes in those movies, but whoever it is has also trained them to associate the sound (well, vibration) of flapping wings with the sound of food. And they reach that food by slithering down through the holes in the grating above the safe-looking corridor through which the dragon is flying. ## Wall of text. Around here everybody likes to write a wall of text. But there is a nice, solid looking surface in front of that wall where a scholar might perch to read and ponder. That's where you put the trigger for the ballista trap. ## The terrible flood of fate I'd think people would know by now to look around and see if the dungeon is reached via a small hole in the surface of Lake Erie before they begin exploring. But they don't, and a surprise is bound to ensue. When you pick up the big golden idol, do you suppose that (a) a victory message and game credits appear, b) that old sock exactly balances the weight so you can escape safely, or c) there is a tiny string tied to the bottom and with it you've just opened a ring of 50-foot floodgates on every side of the ancient wonder of the world you just discovered, which is now going to be utterly obliterated? [Answer] Rocks fall and everyone dies. If the fella got wings, a large net with rocks can be placed all over the roof. Place a moveable floor with a pit-full of water and stakes. Trying to swim with broken bones will be a challenge. You may draw inspiration from D&D books. The 2 main ideas are to bamboozle and to hide the real stuff. Place some stuff with a tiny script, so you need to close in to read. Maybe deface it so they really need to get in close. Another ways is to place an obvious trap, that can be avoided, poorly concealed, then when they try to skip "the trap", they dive into the real deal. [Answer] Put a golden door at the end of a long hallway narrow enough that they have to proceed single-file. When the gold door is opened, it triggers a huge hallway-clearing ballista on the other side. Or a ram, flooding, or whatever else you have lying around that will hit everyone you've lined up. You could fill areas with natural overgrowth of super-toxic ivy, sleeping poppies, or other problematic flora. If the dragons burn it, make sure that the rapidly-spreading smoke and fumes turn into a far greater hazard than it would have been to just walk through. If the smoke is thick enough to obscure sight or other senses, you can use it to add further concealment/difficulty to the other traps around it. If you have a trap that can't survive dragon flame, you don't have to discard it! Just build it into some load-bearing wooden columns. Anyone who tries to burn the trap will bring the entire place down on their heads. :) [Answer] Some very good answers. I'll try to cover some untrod ground rather than rehashing: Assume that not all visitors would be dragons: a fall-away trapdoor-floor also flavour and could take one of your party by surprise, with the potential to catch feet or equipment as it closes. Requiring a visitor (intruder or guest) to expose themselves ... by (say) pressing buttons with wings, hands, and feet. Better not push the wrong one the three hand-buttons when your wings are spread wide... This would also give some non-draconic intruders problems. Multi-stage traps: pits don't work on people with wings ... ish ... but you can shoot at those once they're spread. Traps which can pull - snares work well for this. Species compulsion: Something made of gold that "any dragon is compelled to steal" (if they don't own it) would tempt intruders while not affecting the owners of the building; this depends on the level of innate draconic avarice in your world. User-operated trap A short maze-puzzle with moving walls can easily be made inescapable, if you don't have a friend to reset it. This also allows the party to find a well-preserved previous explorer (with or without an accompanying whip and journal full of notes). Bad maintenance on an intended path could also be blamed for this. Classics In general, if your architecture is dragon-strength then most traps will work, except those which require the victim to fall. The "big closing door" is actually more likely to pinch and hold someone who has a tail, doubly so if your dragons are usually quadrupeds. For things like giant boulders, a little suspension of disbelief can go a long way. More might be possible, depending on the builders' tech-level and maintenance. Anything biochemical is "because I say so", and clockwork or magic can be as advanced as you require. [Answer] Very beefy, but ultimately standard traps will do. Funny thing about flying; the larger you are, the harder it is, and the less control you have while doing so. Odds are a dragon the size of a horse can't daintily hover through a trapped corridor; In our world, there are birds too big to take off without a running start, and their landings are equally clumsy. A horse sized dragon is far larger than these birds. In order for a creature the size of a dragon to fly, it will have to go extremely fast, meaning it will have a lot of momentum. It will be unable to turn in narrow corridors, and will absolutely be unable to fly slowly or precisely. As such, as long as the temple interior is not obscenely large, you can basically ignore the dragon's power of flight. They can't use it indoors; not enough room. regarding pit traps specifically, a flying creature as large as a dragon will not just be able to hover up out of them. To recover from a fall, the dragon will need to build up a fair bit of downward speed first, and then begin to level out in a large, u-shaped flight path. This is simply not possible in a pit trap; how are you supposed to gradually turn a fall into a glide when the pit is only just big enough for you to fall through? Once that's out of the way, all you need are traps robust enough to pierce dragon hide... and also fire resistant. For dragons, your best options will be spike pits, huge spiked pendulums, and maybe spears shooting out of the walls if you have the technology to launch them hard enough. The classic rolling boulder would also work well... in fact, a boulder trap would likely work even better on dragons than on humans; if the corridor is narrow enough, a dragon walking through it might not be able to turn around, and would be forced to briskly walk backwards to avoid the trap. For quadrupeds, walking backwards is often extremely difficult. [Answer] Traps and Prevention Methods 1. Prevention If the dragon never enters the dungeon, it cannot threaten the treasure within, right? There are multiple ways to accomplish this: 1.0: Religion/superstition Yes, I know, in Indiana Jones and Legend of Zelda, people break into, loot, and vandalize sacred ruins all the time, but if the dragons are the only ones there, considering the long lifespan of dragons, they aren't going to do that. Number one, they may have helped build the ruins, or at least have some sentimental connection to it as a former fixture of their community. Number two, if nothing else, dragons should be much more respectful of the past, especially since those to whom Number one applies will take offense at temple raiders and hunt them down with crossbows. 2.0: Strategic Content Simply put, if adventurous dragons easily get in and find nothing they want, they'll return and tell others not to waste their time. The genius of this is that there could be valuables inside, but the stinky red herring effectively stopped them and lessened the threat in one blow. 3.0: Little Space Dragons can take a little discomfort (they sleep on treasure, after all, you think that's comfy? No, but it really impresses potential mates!) but they can't take one thing: little space. There's a reason dragons like to live in big caves! They're like kids with ADHD, they need to move, but instead of running, they prefer to fly. Narrow corridors and tight turns don't just prevent flight, they drive dragons nuts so only the most disciplined can possibly pose a threat to the dungeon's treasure. 2. Traps This has been pretty well covered by other answers, but I want to add some ideas, namely: MONSTERS. Yes, dragons are tough, they are fast, they are smart, but the OP makes it clear these dragons aren't top of the food chain. Elves, goblins, orcs, trolls, and even pixies can pose a danger to them. If they live in the ruins and have laid claim to the treasure, they'll defend it, chanting "Protect this temple! Protect this temple!" Never mind the danger of something that isn't a monster and yet is just as dangerous: ordinary human women! From the fact that Western dragons love to eat them and Eastern dragons can be calmed down by them, never mind the tales of shapeshifting dragons having kids with them, we can safely assume women have a lot of power over dragons. Thus, a sensitive dollface with big eyes could be an ideal guardian for any dungeon's treasure. "But wait," you say. "Wouldn't most dragons just eat her?" Au contrare, the dungeon designers would have accounted for that! Perhaps the dollface's beauty is such that a dragon cannot harm her, mentally or physically, or her charm and beauty is such that any dragon that sees her is automatically bewitched and will do whatever she says. Perhaps powerful enchantments make it so any damage inflicted on the dollface is inflicted on the party responsible, or the dollface must be kept alive because she is the key to accessing the treasure, and if she is killed by the dragon seeking the treasure, said treasure will be magically taken and locked away. It could even be that the dollface's power simply makes the dragon look at their life and decide that she is more precious than any treasure; the dragon would take her and leave, leaving the treasure safe. (This would require multiple dollfaces, preferably spawned by magic within the dungeon in front of any treasure.) [Answer] The classic airlock trap can kill almost anything. All you need is a sturdy room with entrance and exit doors on opposite walls. Only one door can be open at a time. The exit door is unlocked via a puzzle mechanism of some sort that is outside the room. The way these traps operate is that the victim/explorer enters the room and closes the entrance door behind them. Their accomplice then has to unlock the exit door to allow them to continue onwards to the treasure. On the way back, the explorer re-arms the trap before entering the room, which causes the entrance door to open as soon as they close the exit door. You have the freedom to design these to be as deadly as you want. The worst-case scenario is a trap that fails deadly on the first incorrect input. Once someone inputs the wrong puzzle solution, the linkage between the doors and controls is severed and the doors remain sealed forever. Whatever is inside slowly starves to death. The ability to fly only gives you something to do while you wait. A less-permanent version might have a way of resetting itself eventually, but on a long-enough timescale to ensure the victim's demise. For example, an underground temple might have a small artesian well that only produces water during the rainy season. It takes an entire season's worth of accumulated water to reset the trap, and no living creature could be trapped for that long and survive. For added suspense, the thickness of the walls/doors and the distance between the entrance and the unlock mechanism can be designed such that the accomplice has zero feedback about whether they've successfully unlocked the exit or not. That's not a problem for the dragons that designed the temple and know how it works. It's a major problem for anyone else. You can't brute-force the correct solution by guessing. If you enter the correct solution but then try something else before the explorer re-arms the trap from the other side, you'll break the lock mechanism, the doors will be stuck in their current positions, and the explorer will have no way out. [Answer] Floor to ceiling spear - triggered primarily by air movement from flying (as well as other motion) releases a set of sprung-loaded spears through the floor or holes in the floor which will impale a flier as easily as a walker. Toxins and corrosives - the dragon might fly but it can't avoid touching some things, or passing through some places. Temptation - gold piles hiding a trap? I'm really trying to think of one that removes the ability of the air, to support flight, or targets the flying system itself, as in, animals that fly usually have extreme adaptations to make flight possible (hollow bones, airflow/breathing systems etc) ]

Subsets and Splits

No community queries yet

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