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[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. The main problem with sending interstellar messages is that with the distance traveled, their power gradually decreases due to gradual scattering ( diffraction). Imagine that you threw a stone into the quiet surface of a lake: from the source stone, circles started to go in all directions, but the further they diverge, the less noticeable they become. The same thing happens with radio waves: if you calculate approximately, then twice the distance from the communication source will reduce the power of radio waves by four times. As you can see, detecting such radio waves at a distance of several hundred light-years from Earth will be a difficult task for space civilizations. And here is the whole question: how can we send an interstellar message in all directions ( since we want to make ourselves known to everyone ) so that we can be heard? Note: please describe the technical features in as much detail as possible and give the appropriate calculations, as if you really want to make yourself known as loudly and further as possible. Also, please do not offer answers related to really huge energy costs or the use of astroengineering, such as the construction of the Dyson sphere. The signal transmitted by our civilization should be focused on civilizations of technological development similar to us ( starting from the mid-20th century ), but if you know how to make the signal available to less developed civilizations, for example, at the end of the 19th century, I will be happy to hear from you. [Answer] **Use the sun.** Stars can be detected at a distance. They are hot! Exoplanets are detected because of the interruption they produce in the output of their suns as they pass between the distant viewer and the star. You do not need to have planetary mass to interrupt the output of a star - a huge flat object would do just fine. A series of these objects spaced around our sun would interrupt its (very energetic) output to a distant observer. They could be spaced so that their transits could be interpreted as a series of prime numbers. That should be adequate to demonstrate that intelligent life is here, ready to welcome our new alien overlords. Prior art: <https://en.wikipedia.org/wiki/Tabby%27s_Star>. - a star which attracted attention because of periodic dimming thought to be from something in orbit. [Answer] A Self-Reproducing Interstellar Probe <http://www.rfreitas.com/Astro/ReproJBISJuly1980.htm> It expands exponentially by converting parts of each solar system reached into copies of itself. It will eventually cover the entire galaxy. [Answer] # Use a Bomb To be more precise, use several many. If you intend to send a message everywhere, attenuation is a certainty. It is unavoidable. So you have to up your transmission power. The sun is an excellent idea, as [suggested by Willk](https://worldbuilding.stackexchange.com/a/186441/36850), but you appear to be down on that, so another option is popping a gigaton-range device, ideally as far outside the solar system as we can afford to drop it. Attenuation will still be a problem, but anyone with a (powerful enough) radio telescope pointed in our direction is going to see a sudden, inexplicable bounce in power. Set them off at irregular (ideally mathematically patterned) intervals, and that should be enough to let anyone looking for intelligent life know that we're here. It will be monumentally expensive, of course, but any plan to let the *galaxy* know we're here is going to be expensive. --- Edit: Clarification in light of comments. Even enormous bombs are going to require that other civilizations be looking *right at us* when the radiation from the bombs' detonation reaches them. A gigaton-yield warhead produces ~ 4.18 \* 10E18 J of energy. By comparison, the sun produces 3.8 \* 10E26 J per second. So for an observer, this would be an apparent magnitude 40 higher than the sun at the same distance. This is why you'd want it out of the solar system, ideally out of the plane of the ecliptic, in a place where that amount of energy *wouldn't be expected to come from*. [Answer] Don't send the signal to all stars at once. Instead send a focused message with a very narrow spread rather than an omni-directional transmission. Focus the spread such that it only spreads to fill the area of the goldilocks zone of each star you target; so, by the time it reaches any civilization there it will have the same level of dissipation as an omni-directional signal traveling between two inner planets within our own solar system. Doing 1 star at a time this way may seem inefficient, but compared to the time it takes light to travel between stars, you could still cycle between all the stars in the galaxy much faster than it would take the signal to reach the most distant of stars. Infact, there are only 133 stars within 50 lightyears of Earth <http://www.atlasoftheuniverse.com/50lys.html>. Since light is so slow anyway, you should probably just focus on these if you hope to get any response to your message within any humanly meaningful time frame. [Answer] Continuously denote nuclear weapons in the atmosphere of one of the planets (preferably not Earth). The idea is to produce a large number of short lived isotopes of very heavy elements that can not be explained as a natural occurrence. Then when your aliens are searching for planets and decide to do some transit spectroscopy, by looking at a the Sun through the atmosphere of one of the planets they can then pick out the elements that make up the atmosphere. So if they start to see lots of Fermium (atomic number 100) they will either assume a Supernovae exploded within the last ~hundred days (as the isotopes are short lived) or someone is blowing up nuclear weapons. Given that supernovae are very bright and easily detected[citation needed], I expect your aliens will suspect the later is occurring. This is the more explode-ly version behind the recent detection of phosphine in Venus's atmosphere. [Answer] You could build a light array in orbit around the planet which sent extremely large pulses of light in a binary pattern that would be recognized as unnatural by scientific observers on other planets, and make the message a short one, that way increasing the likelihood that the message would reach some destination. You could also use a totally violet light to do this as pretty sure this does not exist as much as one would think given the light is high energy. You could also convert entire dead planetoids into the signal lights and power them from the local sun ? Light we see now is sometimes reaching us, supposedly, from distant stars that are long dead. [Answer] # Supernova If the requirement is to make every star in the Milky Way see us, there is not another way do the things you ask: * "You really want to make yourself known as loudly and further as possible" * "Send an interstellar message in all directions" Your question as posted has no answer at all and simply can not have the "Hard-science" tag, for these reasons: * "Please do not offer answers related to really huge energy costs" * "Please do not offer answers related to the use of astroengineering" Because the question creates an unanswerable problem with its constraints and parameters, and the Hard Science tag; this is the answer to the problem in the title: # Q: How do I announce us to the entire galaxy? **Hard science answer:** # A: Supernova [Answer] I can't remember who suggested this (possibly Arthur C. Clarke?). Dump a few thousand tons of an isotope of some element that is either very rare to find in a star like the sun or even one that doesn't occur in nature. Done correctly, you've just added a very large "Wow!” factor to anyone checking lines in the sun's spectrum. The drawback is that the best case scenario is that aliens decide this cannot be natural. It's absolutely not suitable for anything more than "Someone's dumping odd materials into a star for some unknown reason. Maybe it's a signal we should respond to or maybe it's a crazy culture that uses their own star as a trashcan.” [Answer] Build a lighthouse in orbit. Basically a solid slab of diamond, add solar cells and something similar to hubble, compute the orbits of planets in habitable systems you looked at, compute where they will be dependend on the distance. Send a laser pulse, with your cultures encoded information. On the planet it will look like a disc of light, racing at rotation speed against the rotation direction of the planet (40.000 /24h => 1666 kmh). Dark Forrest theory dictates though, that you should do such a thing only when you go extinct, aka it doesent matter anymore. Ufos are the gravelights of the stars. ]
[Question] [ There is a veil which separates our reality from a parallel dimension that contains Eldritch abominations. An predatory empire has discovered that they can harness the power of this realm by summoning demons across the barrier. This is done through the use of human sacrifices. The more powerful the demon, the more sacrifices are needed. The sacrifice of one human being would be equivalent to one measly familiar, while the death of thousands would yield a more powerful daemon. Weaker daemons are subjugated by their masters and used as servants. Stronger daemons cannot be subjugated in this way due to being more powerful. Instead, they are used for specific purposes before being sent back to their realm (specific spells, reveal dark secrets or information, create items, etc). This empire preys on its neighbors to provide the fuel it needs for their rituals. This includes the weaker states surrounding it as well as more powerful Nations further out. As such, thousands of individuals are taken from these surrounding nations as a form of tribute. However, an empire in our world known as the Aztecs also operated under this mantra, taking slaves from other nations through conquest. What eventually happened was that all of their enemies banded together with the help of conquistadors to overthrow them. The Aztecs had pissed off so many people with their constant need of sacrifices that their weaker nations destroyed them through strength of numbers. Surrounding nations of this demon worshiping empire aren't likely to take the kidnapping, torture, and sacrifice of thousands of their people for the sake of this empire's survival lightly. You would think that this empire can simply call upon their demons to fight and defend them, but it is not that simple. Demon summoning requires many valuable and hard to get materials, which often can be used only once. Rituals are time consuming and expensive, and individuals can't just call down an army of demons to back them up. training and skill are required for summoning. Certain parameters must also be met, such as specific locations, dates, and environment. The economic factors alone would put a large amount of strain on this empire, not to mention other factors. Therefore, warfare is not a long term solution in most cases. This empire needs to continue taking large amounts of tribute from its neighbors while at the same time preventing them from taking sides against them. How can they avoid this scenario and maintain the status quo? [Answer] **Very easily** If you look at the history books, your assumption of a slave revolt being successful is, unfortunately, incorrect. Revolts can work on a small scale, but on a large scale, slave revolts *by themselves* have never stood a chance against whatever regime they were up against. Sure, the Aztecs kind of made enemies of whoever *wasn't* an Aztec, but it took the Spaniards to successfully organize the slave revolt and overthrow them, because the Conquistadors actually knew a few things about fighting and had access to guns. Take Sparta - the slave to citizen ratio in Sparta was 20 to 1. That is, 1 Spartan to 20 Helots. Sparta had slave uprisings, but they never succeeded. Now, why is that? Well mostly because tyrants are good at their job of being tyrants, i.e. spreading fear and misery. As in, in Sparta, if they got a *hint* that a certain Helot wanted to revolt, they'd send in a death squad to kill that Helot, their family, their friends, and every poor bystander in the building while they were doing that. In other words, as long as you're willing to exploit and dehumanize the people you're beating down continually, you can drive the light of hope from their eyes and have them do nothing but cower in fear of the very mention of your name. Kind of like the real Aztecs, who were also terrible people. On the other hand, should there be nations of equal standing with the slaves, then there is a chance of success. But you only mentioned weaker nations. [Answer] **The empire grows a lot of food.** That is what they are doing with the demons. The demon secrets, special items etc are all deployed to one end: grow food. And they grow it - lots of it, and it is good, not demon flavored at all but crunchy and toasty and delicious. Lots of food means lots of full bellies which means lots of people. That is why there are so many people out there. Thanks to the empire's efforts, everyone eats. The slaves provided by the outlying areas are bought and paid for by the empire - with food, in a fair trade. Plus the neighboring regions get to pick who goes - they provide their criminals, sick dying folks, folks they themselves capture (or trade for!) from areas further out. It is a good system for almost everyone. No war, everyone fed. [Answer] This is more or less what happened with slavery, with the Europeans taking and transporting millions of Africans to the New World over many decades, effectively sacrificing them to the gods of economics (or Mammon, if you will). They also needed many other resources (gold, diamonds, land etc), which they took by similarly violent means with little effective opposition by the locals for centuries. The Africans never successfully fought back and slavery was eventually ended (more or less) by other means. Unfortunately, things tend to favour the oppressor if they are well-armed and well-organised compared to their prey. "Whatever happens, we have got/the Maxim gun, and they have not". [Answer] The Aztecs got overthrown because an outsider with advanced technology sided with the local tribes. Without said outside, the Aztecs could have continued sacrificing people to this day. As such, to make it an eternal empire, make their army advanced. **They have demons which give them modern equivalent technology** They have demons that can summon fireballs, they can summon demons of great power and little restraint in crowded areas, they have more powerful magic due to their advanced demon summoning. This isn't something that can be replicated by outsides, because their people are being sacrificed en masse. **The threat of an attack is enough to cower those around them** Using demons in warfare is very expensive, and threatens the economy of the nation. They can do it, but they don't like to. Fortunately, those around them know what happens if they don't behave. There are ample stories and examples of places destroyed by the empire. They are afraid of being destroyed if they rise up. **Spying magic is excellent, and they use this to prevent a large scale rise up** They know secrets of divination beyond those around them, and have demons with great stealth. Any attempt by those around them to unite can be spotted, making it much harder for their enemies to unite. They can simply kill whoever proposes an alliance as an example, at minimal cost to themselves, or offer demonic aid to someone who doesn't want to ally with their neighbors. [Answer] ## *Divide et impera* (Divide and conquer) Of course, your risk is higher if those oppressed people all work together against you. Fortunately, preventing it is easy; the main risk being that you empire becomes divided by internal frictions itself.. First, geographical division. The peoples to the west of the empire will not have an easy way with organizing with the peoples to the east of the empire. Second, political division. Do not allow your victims to become centralized countries. Make lots of differents countries of them, so each one is technically independent; making coordination very complicated as there are lots of rulers with no fealty to one another. Of course this has some disavantages, as it implies you need a more thoroughly coordination (instead of getting a delivery of 1,000 prisoners, you need to manage 100 deliveries of 10 prisoners each from each of the polities). Building on top of that, play those countries one against the other. Those that are harder to control or too far away from you can get a better deal by helping you control your other victims; they will be left unmolested and maybe they will get a cut of the profits. Bonus point if you can stir previous animosities between countries and/or cultures. European colonial powers were particularly adept to this system. And last, social division. Provide something of value to the higher classes of those countries so they enjoy the *status quo*. If you want to introduce something supernatural, a life-extending potion or the like. But usually providing safety and stability for their own positions can be enough. If an internal revolt thratens them, send your army to help them. The nobility will be less likely to revolt if they are not personally threatened by you, and if they fear their own people revolting against them and count on your support. If, against their own interest, some nobles or kings are against you, just support some pretenders to their position who are willing to deal with you for your help (there are always some of those). And of course, sometimes those rulers will be deposed by a rebellion. But then, that rebellion with be isolated among other countries ruled by an elite sympathetic to you and you will have advance warning that a challenge to your rule has been raised. ## Secrecy and religion Of course, there is no need to tell the other countries what you will need the people for. Just tell that you will enroll them in your army, or settle them in some unoccupied region of your land, and you may ever end with volunteers. And lastly, engineer a solution where this sacrifice is actually seen as martyrdom and those who willingly offer themselves to be butchered will be revived in a paradise, and then you are all set. [Answer] **Strong conventional army** Plenty of real world nations have survived long periods of warfare with their neighbours. So long as the demon-summoning nation has a strong army, solid leadership and a functional economy they should be able to keep most of their enemies at bay, especially if they are also: **Flexible** Even a strong nation would struggle to fight all its rivals at once (Just look at Brandenburg during the 7 year's war or France during the 30 year's war). So it would make sense for the demon-summoners to make alliances where possible. If they team up with other nations to subjugate the weak, both they and their allies can benefit from raiding and territory gain. They could also be pragmatic in their approach to capturing slaves. In times of military weakness or failure they could use their own population for rituals. They might also institute a slave trade so that those willing to trade them captives outside of wartime are rewarded with trade and money. ]
[Question] [ One of my characters (who comes from Earth) wants to open a restaurant in a fantasy world. This world is currently in its medieval era. The restaurant would serve all sorts of modern food; deep fried, baked, you name it and they have it. The restaurant is equipped with modern kitchen appliances and facilities. Given medieval farming and food preservation techniques, is it possible to create foods like we have now with the available ingredients? [Answer] Considering @In the name of the story’s update that the protagonist **has** modern refrigeration and transportation available to him/her/them, the only barrier should be the fact that many food ingredients would not be available in the place where the restaurant would open in. Assuming that the restaurant will open in Medieval Europe (as that’s what most people think of when they refer to the medieval era), the only ingredients available to the protagonist would be those locally available. Let’s say that the restaurant opens in medieval England and the protagonist wants to serve the following foods: * Hamburgers * French fries with ketchup * Hot dogs * Pizza * Salad * Sushi * Cupcakes * Burritos * Fried chicken * Soda * Beer Here’s how it would turn out: * Hamburgers would work, as wheat used to bake bread, cattle, and lettuce already existed at that time * Tomatoes are a Western Hemisphere crop that would not yet exist in England * French fries and ketchup would not yet work because both potatoes and tomatoes are New World crops * Hot dogs with wheat bread and sausage could exist but without ketchup (although mustard would work) * Pizza would not work without tomatoes; wheat, olive oil, cheese, and various toppings were available in medieval England * Certain vegetables that could be contained in a salad existed at the time * Depending on the exact era of the Middle Ages that you are focusing on, rice was **or** was not yet available in Europe, but tuna could be caught from the ocean * Cupcakes made with wheat, honey, butter, eggs, milk, yeast, and salt could exist (sugar was not yet widely available in Europe) * Burritos made with wheat tortillas containing meat and fava beans could be prepared * Fried chicken using wheat flour, eggs, salt, and lard or ghee could be made * A soda could be made by combining mineral water, honey, and blackcurrant juice (primitive sparkling Ribena!) * Beer could be made using barley, hops, and yeast [Answer] There was no refrigeration in the Middle Ages. So ingredients had to either be sourced locally, or preserved in some way. So no fresh oranges in Stockholm, for example. The next problem you have is that some ingredients haven't been invented yet. Just as an example, look at all the different kinds of pepper the hot pepper community has invented in it's race to have the hottest pepper. Next, many ingredients have changed quite a bit since the Middle Ages. Fruits and veggies have pretty much all been bred to be larger, and in many cases more flavorful. Livestock have been bred to produce meat with specific marbling qualities. Essentially you're missing out on ~600 years of artificial selection. One example of an ingredient you miss because of this would be Kobe Beef, but there are others. Last, some ingredients were only found in the New World. Tomato, potato, and chocolate to name a few. With all this in mind, some recipes would be possible, while others wouldn't. Exactly what is available depends on exactly where you are. [Answer] I suggest making your restaurant an ice cream parlor. Most modern food preparation techniques were used in the middle ages. They did not have microwaves, but steaming or putting something to stand near the fire could get similar results, just slower. It was certainly possible to create foods similar to modern ones if the ingredients were available. To see the variety of dishes that were actually prepared I suggest reading some medieval cook books. The big difference is that the ingredients for modern cooking were either not available, or too expensive for most people to eat them. The people who could afford the quantities of protein (especially beef), refined white flour, spices, and sugar would eat at the high table in their own hall, not at an inn or tavern. A medieval celebrity chef worked for a VIP, rather than opening restaurants. A few wealthy people in the right areas might be able to have ice brought from a mountain glacier, but most people in most areas had no access to frozen dishes if it was warm enough to make them enjoyable. Fermented fruit juices, milk, eggs, and honey were all reasonably available at prices a merchant could afford, at least in small quantities as a treat. If you did your buying quickly, at the right time, you might even be able to get unfermented fruit juice into your freezer. It is sweeter, and freezes better. Cook everything to kill bacteria before freezing. Based on some comments on another answer, the ice cream parlor could also offer, based on distillation, completely clear, safe drinking water with ice in it. [Answer] There were no restaurants as such in medieval Europe (just odd bakeshops and vendors for working types who could not get home to eat). The concept was quite alien to them. You would have to work extremely hard to build any sort of clientele -- those with the money would much rather be in their own grand homes, those without cannot afford to eat there. That, and getting people to eat strange foods, is going to be a huge challenge. It took a long time even for things like Chinses and Indian cuisine to catch on in the West. Far better to get employed as the personal chef of a king or noble and become famous for hosting the most amazing feasts. ((BTW a not totally dissimilar concept appears in my own War of the God Queen when a 19th-century Frenchwoman timeslipped to the Bronze Age decides that the locals need the civilising effects of proper cookery and makes the most of local ingredients)) [Answer] There hasn't been a lot of innovation in cooking techniques, and preservation is mostly needed to have things year-round rather than in-season. The big difference is transportation. We take for granted meals combining ingredients that don't grow within a thousand miles of each other. If you're attempting to recreate modern american food in medieval Europe, what you'll most miss is tomatoes. Unless you're specializing in desserts, in which case chocolate. You'll also routinely wish for refined sugar, which exists in India and theoretically could be imported, but AFAIK never was. Honey and boiled pear juice are all available, though expensive and not quite the same. Spices should be pretty available, albeit expensive. (Also, no allspice, vanilla or chili peppers.) A lot of them have to be imported from India, but those trade routes exist. But in a *fantasy* world with medieval *technology*, you can decide what plants they have within their trade network. Including they could *all* be different plants, and your hero has to methodically eat one leaf or berry after another thinking "this can kind of substitute for that"... [Answer] I think we're looking at this wrong... The thing to do is bring some of your own produce (stuff that can be grown locally) and focus on culinary traditions that would be unfamiliar to the area. I'm going to assume you're in England (partly because they are notorious for poor cuisine) for my examples, but similar ideas should apply anywhere. Simply serving *period* French or Spanish cuisine here would be noteworthy, and you have a better chance of being able to get the ingredients. Introducing tomatoes or possibly pasta would be huge. Asian fare (Chinese, Japanese, Indian) would be even better, but getting the spices may be challenging, or at least prohibitively expensive. Instead, you might try introducing cilantro and making New World. You mentioned baking. People of the area already knew how to bake meat pies. You *might* be able to wow them with sheer artistry, but without sugar, "baking" isn't going to be much like our modern notions of "pastry". (However, if you can introduce sugar beets, you will probably blow their minds. I'd suggest baklava, which uses honey, but I'd actually be surprised if something like that isn't already known.) I mentioned forks in a comment. One area you might have some success is focusing on dishes that you really wouldn't want to eat with your hands and a knife or bread bowl. Corn already removed from the cob, shelled peas, salads, mashed potatoes, ragout... Most pasta or rice dishes might be good candidates, actually. Alternatively, introduce chopsticks 😉. Introduce [teppanyaki](https://en.wikipedia.org/wiki/Teppanyaki) and/or ["Mongolian Barbecue"](https://en.wikipedia.org/wiki/Mongolian_barbecue). There was already [some culinary theater](https://en.wikipedia.org/wiki/Entremet), but my impression was that it was reserved for the "upper crust" and was possibly wasteful of food and was more about the presentation than the cooking itself. [Answer] Site your restaurant in a seaport; and make friends with shipowners and sea captains. They eat free all year round, if they add a few sacks of rice, dried fruit or meats, or spices to their cargo, or (for only the fastest ships ... maybe favours from the Navy) fresh oranges from Seville or bananas (picked green) from West Africa. Especially if they travel the length of the Mediterranean, let them know of fables you have heard of bitter beans from Ethiopia, and have them ask around the markets for caravans from the Red Sea. Ground up, they make a special drink, but keep that knowledge to yourself. (It's no accident that marine insurance started in a coffee house, run by Lloyds...) ]
[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/110982/edit). Closed 5 years ago. [Improve this question](/posts/110982/edit) In a world where you can die twice, well more like you can resurrect once in your life. Imagine a world where your best-friend that got killed in that tragic car accident or a loved one was killed in war or by another; don't fret they will be coming back soon. Put that bat costume away young Bruce your parents that were killed in that robbery, they will be home before supper. Sounds cool and all but how would society itself operate? Would there be death cults? How would you be judged on a crime if the person isn't dead? Fighting in a war where most of the people you kill will be back in no time. A doctor trying to save a patient that would just come back (most of the time). Being a risk taker or sportsmen. ### Resurrection Trait detail: * When you die, you will resurrect within three days. * When you die, your body stays where it died but a new body gets resurrected at the nearest Ark site so if you got trapped under rocks or drowned you don't just die again. * The Ark sites (which are massive catacombs) are protected by some sort of divine power. They can’t be moved or destroyed and you can’t get killed inside (so no spawn killing) but you will be compelled to leave when you resurrect (so do people that just walk in). * Any injury you had will stay with you, unless you die within one hour of first receiving the injury. * If you died from an Disease/illness and chemicals, you resurrect without it. Does not include an injury that will kill you, but if you were killed all diseases would be cured, but any injury done by the disease (like damaged organs) will remain. * You still age and everyone has "their time" so some people can go their whole life without using their second chance. * Humans are the only ones that get this trait (so that pet dog that died won’t come back—it sucks, I know): + Everyone gets ONLY TWO LIVES, no more no less (unless you die of old age then only one). + The person that dies will have all their memories intact, including how they died, which is fun if you died horribly. + The trait hasn't been with humans for long. The trait with the Arks came about two hundred your ago (called the *Event*). The cause of the *Event* is still unknown till this day. The people that died before the *Event* did not come back to life. So the question is this: **How would society operate if everyone had two lives?** This question is for a friend of mine who is doing a new book and would like some different points of view on how a society would cope with the resurrection trait (he’s not computer savvy) so he asked me to ask for him. I’ve got plenty of his notes and I'm just saying this if the feedback becomes a bit slow (have to ask him and all that) should be fine however. So if you need more details just ask (may take some time to get more notes). [Answer] **Pretty much as it does now, but with a couple of exceptions.** Realistically, you're dealing with a 'one bite of the cherry' scenario. Sure, you get a single, get out of jail free card, but once that's spent, your life is at the same risk as it's always been in today's world. Murder would still be murder. Even if a person can resurrect, it doesn't mean that you haven't harmed the person insofar as their one chance to survive an accident or disease isn't gone forever. Plus, you have a body! Because a new one is created for the individual, the original body still counts as evidence that you've taken life. Unless you know for sure that the person hasn't already been resurrected, the chances that you're killing the person permanently is 50/50 and still counts as intent. I suspect the law wouldn't even change, except to explicitly state that murder / manslaughter / negligent homicide / whatever counts whether the person comes back or not. It seems to be the logical approach. The primary difference here is that resurrectees could actually give evidence against their killer. This may sound like a simple change, but it has massive consequences on how murder would be viewed by potential perpetrators. Certainly, premeditated murder is now much more problematic and you'd find that most killings would fall into manslaughter or lower crimes of passion or negligence. Poisons and diseases would be less in fashion for obvious reasons, but murder would probably entail wounding someone grievously, then keeping them alive for that golden hour so when they return, they're close to death anyway. For those places in the world with capital punishment, there's an added complication to a state execution of course; hopefully a big enough complication to come up with other corrective approaches. I seriously doubt there'd be an increase in death cults or the like; taking your one shot at a 'reboot' away seems like a silly thing to do in the same way that it's silly to risk one's life now. That said, I suspect that there may be some thrill-seekers who take much bigger risks before their first 'reboot'. You might find (for instance) that skydivers try out pulling their chutes at lower and lower altitudes for the rush of it, knowing that they still have a chance at living again if they get it wrong. It's actually far more likely though that this resurrection process could create an underclass in society. Right now, many employers prefer younger recruits, for example. Why? Because they cost the same amount of time and energy to train, but can provide more benefit to the business over time simply by working longer. If that young person still has a resurrection pass though, the chances of that benefit being realised is actually better than if they don't. So, people who've used their shot may be overlooked in preference to those who haven't in employment situations. If you think military for instance, it may even become a requirement. Those who've still got their resurrection shot can be trained and that training isn't necessarily lost because of a lucky shot by the enemy on a battlefield. They could come back, learning from the experience, becoming better fighters as a consequence. Sure, it's still only a single reboot, but it's one more than soldiers get now. According to your established rules though, combat tactics would probably change to more 'soft-kill' options. Design weapons that incapacitate, but don't kill, at least for the first couple of hours. That way, your wounded carry their wounds into their next 'life'. Keeps them combat ineffective, even through the resurrection. In short, you'll get a few more risk takers, but the discrimination that's now possible through people being on their 'last life' may well dissuade people from that course. Murder and war will change (less reliance on biological or chemical warfare) more towards 'soft-kill' options but generally speaking, not much else would change. Given that you've already stated that a person's life expectancy hasn't been increased through this process, there'd be no material effect on global economics except that statistically, average lifespans would rise for a while as (final) deaths by accidents and diseases reduce. Realistically though, we'd take this in the same way we've taken most medical advances over the last century, like anti-biotics; a welcome relief from conditions that would have proven fatal in the past. [Answer] ### Murder Murder would become less frequent. Why? Because it has less impact. Half the time, the person would survive and would be able to testify against the murderer. Which takes away one of the major reasons for committing murder. The remaining murders would be more likely to be crimes of passion. Or murders of people known to be on their second life. There would be a police station immediately outside the Ark. The police would ask everyone how they died with details like location. So they can recover the body and if necessary, arrest a perpetrator before the victim returns to the world. They may also have therapeutic resources there to counsel the deceased. The more horrible the death, the longer they might keep the person. In terms of punishment, remember that attempted murder is also a crime and often shares the same punishment as success. I don't see any reason why that would change. There may be some things that would have been prosecuted as murder that would now be prosecuted as reckless endangerment or similar. If the victim survives, then often the victim will have the opportunity to determine whether to prosecute or not. But I wouldn't expect the law to change much. ### Paired crimes Other crimes might become less frequent as well. This is because murdering to avoid witnesses no longer works reliably. The criminals would need to know that that particular person was a second-timer. Studies have shown that likelihood of punishment has a greater deterrent effect than increased punishment. So we should expect the greater chance of a surviving witness would make crimes less likely. ### Capital punishment Capital punishment would be harder to apply. For people who haven't already used their second chance, it would require two executions. Another reason to keep people from leaving the Ark without police review. ### Suicide as an escape mechanism It would be possible for someone with a second chance to escape prison by committing suicide. Another reason for police review at the Ark exits. If it is easy to predict where and when someone might resurrect, this might lead to centralization of prisons. That way the entire Ark might be inside prison grounds. If prisoners are the only ones who live within that Ark's range, that might be the simplest option. Another option would be to execute every prisoner who has a second chance remaining. Of course, that may be considered inhumane. [Answer] One thing nobody has mentioned yet: you've finally got a cure for cancer. (Also most other deadly diseases, but cancer is probably the only one we have no definitive treatment for). The question is what exactly "dying of a disease" means. If you're mostly dead, can the doctor push an overdose of morphine, so that you wake up healthy and cured, or have you died from a drug overdose? [Answer] One thing no-one has mentioned yet is the economic possibilities of having a second body for free. The businessman inside me says you could do alot with that. # Organ donors > > In the film [Never Let Me Go](https://en.wikipedia.org/wiki/Never_Let_Me_Go_(2010_film)) the plot goes something like this; > People are artificially grown and subsequently harvested for their organs. > It's implied later in the film that the clones are turned into a battery farm process, made "less aware" and that the protagonists are from one of the last places that considered the ethical implications of raising humans purely to harvest their organs. > > > One of the major issues plaguing modern medicine is organ failure and spare organs (you can probably see where I'm going with this). One area of the [black market is organ trade](https://en.wikipedia.org/wiki/Organ_trade#Illegal_organ_trade). The reason this is done on the black market is obvious - people need to die (permanently) for some of these to become spare. Not as much of a problem in your world. Once you resurrect and leave your old body behind, you have one of two things; 1. Spare organs for yourself, pop them on ice and wait a while 2. Spare organs you can sell. For the individual who has kept themselves healthy, this could potentially be quite lucrative. Selling organs could become a legitimate form of spare income. Want that new car? Donate a kidney. Want a new house? Donate everything. As more people do this however, the return on organs is likely to drop. [Supply and demand](https://en.wikipedia.org/wiki/Supply_and_demand). Making things like kidneys commonplace, as you don't need to die to produce them. This would force an emphasis on quality and likely cause people to come up with health programs they sell to others specifically for the goal of growing the best organs ever. Similar to the Atkins diet but more grim. This doesn't have to mean suicide, but if you keep your organs in good nick and suffer an accidental death it does create extra wealth by accident. If suicide rates do increase due to this, I'd imagine kits or services making this painful and easy would crop up. Similar to [webuyanycar.com](http://webuyanycar.com) but for organs, they kill you painlessly and do the harvesting. At the end you get a lump sum without much of the trouble. For the black market gangs who gain access to an Ark (by securing a perimeter outside) this means they get double the bang for their kidnapped buck. # Body donation Same as above, but entire bodies for medical or weapons research. People don't necessarily have to be dead for this one, particularly in the case of weapons research it may be more preferable to keep people alive for testing. Let alone what might happen to POW's in some countries that [don't favor human rights](https://en.wikipedia.org/wiki/Human_rights_in_North_Korea). This isn't even touching on the ideas brought up in the purge regarding paid murder. Some people may offer a large sum if you are willing to let them brutally murder you. > > This is something that happens in the [2nd Purge movie](https://en.wikipedia.org/wiki/The_Purge:_Anarchy#Plot) > > > # Cannibalism I'm not saying this would cause a sharp increase, but it's possible that some may pay others to commit suicide so they can have the old body to "try". Over time the idea of cannibalism might become less taboo in this society, as one of the more disturbing parts of the act (for me) is that another human has to die for it. If this is removed, the act itself seems a little less horrifying (but not by much). > > However this form of 'humane' cannibalism would rule out leaving the victim alive whilst cutting off limbs for eating, as seen in the [Walking Dead (Hunters)](http://walkingdead.wikia.com/wiki/The_Hunters). As after an hour injuries carry over. > > > But this is unlikely, as people would never be *quite* sure that your lunch is from someone who has a life left or not. This also ties into organ donors, waste not want not. # Snuff films Similar to cannibalism, but for "the arts". # Body ownership This concept doesn't really factor into law past [rights of disposal](https://www.barkerevanslaw.co.uk/2016/05/who-owns-your-body-when-you-die/), however in your world you leave behind a body you can look at first time round. Rights to ownership over a body would have to be written into law explicitly. Where it may be the first body is owned by the second and the second goes to the relatives, followed by the state if none exist. That scenario would probably be the most likely in western nations, where human rights are highly regarded and given. However in other countries where the state doesn't really care (such as [best Korea](https://en.wikipedia.org/wiki/North_Korea)), they may write into law that the state has ownership over bodies. Thus creating an exportable product for that state. This may even go further in countries like North Korea, where it is every citizens duty to have a certain diet up until the age of 25 and then sacrifice themselves for the 'good of the people'. Making this country the largest exporter of quality organs. Would other countries turn a blind eye to this due to convenience? In the same way we do to sweatshop work so we can buy [cheap clothes at Primark](http://www.bbc.co.uk/news/uk-northern-ireland-28018137)? [Answer] Other answers have addressed the effect on people's attitudes from knowing that they have a spare life and I have nothing to add to that. I'll address the effect of the resurrection itself. On death, people will effectively be teleported an unspecified distance (depending on the density of the Arks) and come back with no non-biometric identification. The will then almost certainly be some distance away from their home and the site of their death. I think this would lead to a number of effects. Everyone, in wealthy societies at least, would have to supply biometric identification such as fingerprints or retinal scans so they could be identified after death. There would be a new class of death insurance, where companies would set up offices near Arks so that resurrectees could claim some basic clothing, money and transport. It would probably include body recovery and thorough cleaning and return of all items on the body at the time. Bank accounts & cashpoints would use biometric data too so that people would be able to continue to access their funds. Hopefully governments/charities would be on hand to supply at least basic clothing for everyone coming out of Arks. If anyone was resurrected without identification then it would be difficult to prove identity and hence citizenship. Imagine a Hispanic resurrectee being resurrected in Texas in the current political climate, for example. In extreme cases, people might be willing to commit suicide just so they could be resurrected in a different country and claim asylum. Hardline governments may then have to create no-go areas inside their borders to ensure that their citizens are always nearer to Arks inside their country than outside. One final thought - Nathan Hale would have to say "I regret that I have but two lives to lose for my country" [Answer] I'd like to consider the logistics of the Arks and some of the special circumstances not covered in other answers. -What about people who can't move themselves? From the description it seems that when you reappear in the Ark you are compelled to leave, but what if you are paralyzed and that wasn't cured by the Ark, or if you are a baby too young to crawl? Are you magically transported out or do others who have been reborn need to help you? -There would need to be a system in place to manage those coming out of the Ark who can't get themselves back to where they came from or who have nowhere to go. (i.e. children, people with dementia or amnesia, the elderly, etc.) This could be a government refugee camp type of thing. -I imagine there would be many who take the Arks as proof of God. This could have many implications including an uptick in religiousness, and fighting over the Arks. On the other hand if everyone regardless of faith could come from any Ark, it could cause people to realize we are all the same and no one faith should control them. -It would probably be common for families to travel to the Ark you are expected to appear at to wait for you to come out. That could lead to a whole industry around housing those families while they wait. Trying to encourage tourism that way: "Oh you are already in this area, why not make it a vacation?" It would boost the economy in places where Arks appeared. There would also probably be rebirth celebrations and second birthday cards in drug stores. -People may want to keep rebirth confidential because if everyone knows you only have one life left, someone might decide to murder you. If they do there could be privacy laws about the area around the Ark and the intake centers, no cameras and records fall under HIPPA. -I know someone else said death cults wouldn't become a thing, but why not? There are certain religions that refer to baptism as a rebirth, maybe they take that literally and when someone converts they are killed and reborn into the new religion. This could become illegal. -Because Arks appeared suddenly and without cause there could also be those who consider it unnatural. Maybe another religion forces their members to loose their first life when they are indoctrinated because "God only intended you to have one life." -I could see celebrities using up a life as a publicity stunt. -What about people who arrive at the Ark with nothing? Say a family gets in a car accident and only the children get reborn? Someone at the Ark is going to have to handle that. -Also how old do you need to be to allow rebirth. I'm thinking along the lines of infants and premies. Do you have to have been fully born to allow a second chance? What if a child dies during birth or a C-section, will it come back? If this line is fuzzy that could lead to parents waiting at Arks not knowing if the baby will emerge. If a premie dies will it come out of the Ark healthy and bigger? If so you might find parents letting a premature baby die so that it will come back healthier. -In video games everyone would start with at least two lives. -You know how there are always people who says stuff like "You'll understand when you are older"? Well expect to start have your opinions invalidated with: "You don't understand because you're not on your second life." This is getting long so I'll stop now. But the point is that there are dozens of cultural changes that don't have to do with murder and capital punishment. [Answer] I'm not going to try to address all of the societal impacts. That's way too broad. What I will do is disagree with my predecessor answers. People will become much less prone to death. **Life is Cheap** Taking away a life would become a much more frequent method of punishment because it doesn't matter nearly so much. Further, havind died the first time and having lost decades if not most of a lifetime, the threat of a second round of capital punishment becomes much more real. *In our world today there are a great many people who believe capital punishment as a deterent is a failure. They're right. Criminals have nothing to lose and the threat of death isn't actually that strong. It is a way of permanently removing from society someone who has proven themselves a constant and irredeemable threat to society.* *Now we can take two lives. Capital punishment means something because, having lived through it once, you have a dang good reason not to risk it again. It's the ultimate fine for misbehavior.* **Risk is for Suckers** People in general become much less risk averse. Climb that cliff? Why not? Ride that rickety roller coaster? Sure thing! Play Russian Roulette? How much is in the pot? Knowing that you'll live through it the first time means you can easily and willingly take all those risks, even if they're not your risks. Unprotected sex with Aids? Who cares? Inconvenient baby? Just dump it in a trash can... it'll resurrect. *As much as we aspire to nobility, the majority of humanity takes the path of least resistance: no responsibility, high selfishness. It's suddenly worth the risk to rob the 7-11 or mug the mayor. It has no more risk than losing the lottery. Life will truly become cheap... at least among the first lifers.* **Except for the 2nd Lifers... They'll be Paranoid** The people who have resurrected once will become so risk averse it might actually change the economy. They'll do almost anything to protect the one life they have left, now that they know personally that it will end. In other words, the world will become just a little itsy bit like *The Purge,* where the 2nd lifers are barricaded in safe houses and the 1st lifers are out in the streets shooting everything in sight. (Maybe not quite that bad, but you get the gist.) After all, who cares if there's no risk? [Answer] So I will take it that the only thing that can permanently kill *anyone* is aging (from your 6th point). Let us examine the other ways to die. I will try to be exhaustive. * Terminal illnesses * Accidents (fatal injuries) * Suicide * Murder * Capital punishment ## **1. Terminal illnesses:** I will name the real world and the fiction world as the YOLO world and the YOLT world respectively. Although your 5th point does not logically imply this, I infer that if you don't die from the illness per se, you would still have the illness -- please correct me if I am wrong. For this reason, euthanasia would no longer be an option. However, people would stop trying to sustain their lives through heavy medications or life-sustaining equipment, since that only increases the duration of their suffering. ## **2. Accidents (fatal injuries):** From your 4th point, I take it that everyone would try to die as soon as possible (most of the time) when they have serious or fatal. They will develop ways to efficiently kill themselves in case of these accidents. There might even be a timer that kills you 55 minutes (or however much time you want) after you press the button to ensure that you live as long as possible but also make sure that you don't die too late. ## **3. Suicide:** I briefly covered this in the previous paragraph. But there are other reasons that lead to committing suicide -- depression, etc. Depending on their specific circumstances, people may deem suicide as a viable mean to escape from the current life, or just a temporary solution. For example, a prisoner may escape his/her punishments via suicide. A victim of serious domestic abuse may escape the violence via suicide to find a new family. Again from your 5th point, I infer that if you commit suicide from depression, you technically died because of depression so you get cured from depression. Other mental illnesses likewise. Suicide may even be prescribed as an option to get rid of such conditions. Well, probably the consequence of misdiagnosis would be serious. I think "death cults" you mentioned are certainly a possibility; mass suicide as a religious ritual to be "reborn" with a cleansed spirit or something. ## **4. Murder:** This is the most complicated and the most interesting one. Two hundred years is enough for all sorts of new crimes to emerge. There will be different methods for engaging the first lifers and the second lifers (I borrow these labels from another answer, which I like very much). Crimes against the latter would be the same as in the yolo world, so I will only go into those against the first lifers. If you want to kill someone, you want that person to die permanently, which would lead you to explore options to induce spawn deaths. One way is to inflict an injury and try your best to sustain the victim's life for an hour. Do not let him/her die, from suicide or otherwise. Another option is, you can introduce a fatal illness (viral infection, etc.) before the victim's death, and then just kill the victim instantly afterwards. The victim would resurrect with the infection and die soon afterwards. If your victim is someone already with a terminal illness that makes the job even easier. If you don't want to get caught, you'd better damage the part of the brain associated with memory retention at least an hour before you kill the victim. These options are not always the easiest though. If you want the murder to be quick and easy, and you don't want to go through the troubles of injuring the victim an hour before his/her death, you can consider the more *active* option to cause the spawn death, i.e. kill them as soon as they come out of the Ark. More on this later. ## **5. Capital punishment:** Capital punishment would no longer be used as a means to end the person's criminal activities, but only as deterrence. Combinations of capital punishment and other punishments can be used as well. For example, one may be sentenced to "First Death" + "30 years in prison" or however you want to order it. ## **6. Misc:** Let me now get back to the active spawn death. The existence of this option would make the area around the Ark extremely important. The society would operate differently depending on who dominates the area around the local Ark. Are they run by criminals? Politicians and law enforcement? A religion? Private businesses? If the nearest Ark is managed by law enforcement for instance, you may want to murder the victim somewhere else. I think it would be interesting to see different countries having different "Ark-dominating groups". Arks in some countries are run by ruthless gangs contending over the number of Arks they control, while in some other countries big corporations dominate the areas near the Arks to monetize on them. The bodies of the first lifers, dead or alive, are now much more accessible for scientific experiments (and other uses) which may rapidly advance the medical field; perhaps they would cure aging soon. The extent of implications is up to you. Lastly, amnesia would be a far more serious disease since it cannot even be cured through the first death. Let me know through comments if you need any additional explanation. [Answer] Less difference than you think. The effect of every disease and mistake would be reduced to 50%. So, breaking one leg before would be like breaking both legs now. Loosing half your money before, would be like loosing all your money now. So, people would tend to take more risks, but it would be an evolution of today's lifestyle, not a revolution. [Answer] I believe that no one mentioned any difference about **suicide.** If you die and have the ability to be resurrected, could you deny this opportunity, and die just once? An element of society regarding suicide victims and their families would change tremendously. ]
[Question] [ When a person dies, their soul doesn't ascend to the afterlife automatically. The soul build's a connection with its body while alive, and remains attached to that body in death. Through natural decomposition, the soul gradually loses its connection to the mortal realm. At some point, when the body decays enough,the soul ascends to the next life where it will be judged by god. It will either be allowed into heaven or join the reincarnation cycle to be reborn and given another chance. The ascension of the soul however, is not guaranteed. While it is trapped in the body, it becomes susceptible to supernatural forces. There are invisible predators that prey on and consume vulnerable souls. These are called wraiths, which are angry spirits that have been unable to ascend properly and remain trapped on the mortal realm. These spirits are in constant pain, and seek to take out their agony and misery on the living by killing them. They are also given to consume other lost souls and grow in power. This has been common enough throughout history to be a real concern. Priests are used to expedite the process of ascension. Through performing the necessary funeral rites and given a proper burial, they release the soul immediately and send it to be judged accordingly. These are rites only chosen priests can perform, which involve complex magical rituals that are learned through years of study. This has given the church a strong presence, and has made them a powerful force in humanity. Religion and faith play an important role in daily life of people, and priests are held in high regard in their community. My question is about people whose bodies cannot be found: warriors who died in battle and can't be recovered easily, people who have been murdered and buried somewhere or have gone missing, etc. What is a good way to protect the souls of these people until they can be given a proper burial? [Answer] # Universal morality If this is the way your world works, then it may be a universal morality that all dead should be treated in such a way as to release their soul. I would suggest cremation for those for whom a priest is not available. For example, on the field of battle, it would be a universally 'good' thing for soldiers to burn the bodies of the deceased, no matter which side they fought for. Standards of common decency abound, such as not killing women and children in war. Alternately, the fear of gods is something that could keep warriors from one realm from defiling the holy sites of another realm. Of course, there are many instance where common decency is not followed, and those situations would occur in your world as well. But, the fact that the afterlife and spirits and wraiths and such are *true* and universally accepted would just serve to reinforce this universal morality. Anyone who did not take action to allow souls to depart from their bodies or allowed a soul to be consumed by a wraith might fear that they are now in mortal danger of the same thing happening to them. Perhaps there can be some sort of cosmic karma to make this happen. [Answer] ## Psychopomps Many cultures have had some kind of tradition of [spiritual beings](https://en.wikipedia.org/wiki/Psychopomp) whose duty is to escort the souls of the dead to the afterlife. These beings are called **psychopomps**, which literally means "Guide of Souls". These beings are often gods or animals. These guides could be a natural part of the world, provided by God/the Gods to ensure the safety of their followers. Perhaps one has to be sure to live according to the religious codes to ensure that their guide will be there for them when they die. Alternatively, they could have been created by man, specifically to guard the souls of the dead; perhaps there are a handful of priests who train all their lives to become powerful spiritual warriors, able to leave their bodies to find and help the souls of those trapped in the real world. Perhaps there are warriors who are trained for years to become models of selflessness, powerful fighters and guardians, who are then sacrificed and their bodies are preserved, allowing them to remain tied to the world as psychopomps. In any case, there would be those - mages or priests - who specialised in communicating with the guides in order to find these bodies as quickly as possible. ## Body-finders If there are no psychopomps, then there is an opportunity for profit. Adventurous people could be hired to go to battlefields, plagued villages, dangerous places, to find the bodies of the deceased and return them for proper burial. Some body-finders would be respected, spiritual men, who journey ceaselessly across the land seeking out bodies, perhaps by magical means or by communicating with the dead, to return them without thought of reward. Others would be pure mercenaries, hardened fighters who go to places of danger to recover bodies and then hold them for ransom. Others still would be beachcombers and fishermen, finding bodies washed up on the shore or floating in the sea and taking them to the priests. The priests would have a duty to reward anyone who brought a body to them. ## Blood Magic Blood relations have always had a powerful folkloric connection, and in a situation like this that could probably be exploited. There could be people, perhaps mages or priests, who are able to trace a person's family from their blood. If father goes away to war and doesn't come back, a priest or a mage could take some of their blood or just their psychic fingerprint and use it to home in on the location of the body so that it can be retrieved. Of course, this can be combined with either of the other ideas, or all could be used together. [Answer] ## Blessed Trinkets From the Church Perhaps you could expand the notion of the soul binding to a body over the course of life, to include any object person keeps close to them at all times. Individuals could keep amulets or rings, blessed by the church, that are meant to protect their soul for some time after death. The length of time for which an amulet will last depends on the materials. The degree to which they can keep the soul safe from supernatural forces may also depend on materials or the level of blessing placed upon it. And of course you could use the price of such protections to generate revenue for the church or if you want to limit who can get their hands on such protection. [Answer] ## By the courtesy of the other dead I don't know if all cultures believe in souls ascending to heaven, so relying on your enemies in battle may not be wise. However, since not all your dead are trapped (those who are reachable can be helped), it could be a matter of courtesy in those cultures to not ascend the minute you are free, but have a look around, especially in times of war, for fellow souls which are trapped and free them before you go. Army units in particular can have it planned ahead that everyone who dies makes sure all the others are alive or descended. [Answer] **Purification rights** Why wait until death to start preparing for the next step? Through appropriate rites, a person can learn to stretch their connection to their spirit and render it elastic, putatively for out of body experiences and such. Warriors, on the other hand, may well have little rites that prepare their breath for departing. When their time comes, then, the noble dead could then break free easily and launch outward. A special prayer card or potion could set things up in a similar manner, erroding the ties to the mortal coil while it lasts. Regular upkeep of the meditations (or whatever) could lead to an interesting world view, as the spirit grows freer to act apart from the body. **Effigy** You want to free (or trap) a spirit? Make a symbol of it's body and enchant it to share that strength to bind them. You then lure the spirit to a jar with it or destroy the binding. [Answer] Pray for the unknown soldiers. That is why they have the Tomb of the Unknown Soldiers for those who died in battle. [Answer] **There is No Other Way** Consider keeping your current situation. Historically, cultures who believe strongly in burial rituals for the protection or honor of dead warriors view the denial of such rituals by the enemy as tragic in the extreme. In The Iliad, for example, Achilles' initial denial of traditional burial rights for Hector enrages the Trojans and serves as a major plot event. **Chaplains** Armies often employ chaplains--representatives of a church--during their campaigns. In your world, chaplains might have a protected status on the battlefield, similar to medics in many earth wars. Killing one, on purpose or by accident, might incur the wrath (or the belief thereof) of either one's superiors/peers or the divine. ]
[Question] [ Suppose on Earth there was a hidden army in Antarctica. This army is highly technologically advanced and equipped with highly advanced technology. One day, on routine patrol of the United States, one of their planes has an accident and crashes. The US government comes in and steals their technology and slowly releases it to the public. Years later when all of the United States is using the advanced technology that was stolen, then hidden army decides to invade. During the invasion, soldiers on both sides are killed but wouldn't troops on the United States eventually pick up some of their technology and realize its suspiciously similar to their own? How would the government cover up that the technology wasn't theirs to begin with? Edit: this situation would be as if over night the entire army of the united states was copied and used against us, in this situation they have simply too much of "our own" technology to have been stolen [Answer] 1. "Damn those Spies stealing our technology!" 2. "Yeah, we probably bought it from the same Japanese syndicate" 3. "Don't ask questions son, you're in the army now" 4. "So what?" Ak47 and M16 is very similar yet no one asked the question who ripped off whom. Same for jets (ok we all know they all got it from Nazis on the moon). In what the weapon would be similar? The gun goes boom and there is one end you should keep toward the enemy? Striking similarities Watson. [Answer] I am going to focus this question. I believe the question is specifically about keeping the "public" from knowing that technology was stolen from somewhere external as opposed to developed internally. If we are talking about the Modern United States, then we can make some assumptions. 1. The "public" refers to anyone that was not part of the top secret project that "stole" the technology. 2. The "stolen" technology would be repackaged as "new" technology. 3. There would be a whole chain of people related to the "new" technology: manufacturing, research, etc that *would likely realize that something is wrong* Since most technology is the process of iteration and can be back-traced. And this technology would not be able to be back-traced. 4. There would be a small group who knew that the technology was stolen. In order to maintain the secret from the "public" The government would need to either isolate these people involved in the chain of the "new" technology, or "include" them in the secret and swear them to secrecy. This would probably be the first thing to happen. Once the "new" technology would be released to the "public" a cover story would need to be created. This cover story would need to include a lot of false evidence and constant care would need to be given to maintain the cover story in case of journalists or curious people looking into it. Likely, that would mean that anyone getting to close to the information would need to be "removed" from the public or included in the secret and sworn to secrecy. Assuming that all those sworn to secrecy, involved in the project, or that know about the "stolen" technology would be loyal, and that those who would not be loyal would be "dealt with". You could maintain this cover story for a long time, perhaps indefinitely. However, once the "war" happens and the troops using the "new" technology would notice the enemy is using the same technology you would have a problem. There are not many choices for how the enemy would have the same technology. Either they stole it, or we stole it. The only real cover story then can be that the enemy stole the "new" technology. Since it would be unreasonable to say that the enemy must have developed the same technology on their own. In order to keep this hidden, it would mean that a policy of no prisoners would need to be maintained. Total annihilation of the enemy would be required, as well as all information and technology they had, especially manufacturing plants and scientists who would actually know the process and history of these technologies. The government would likely need to initiate many strange policies for their soldiers - commanding them not to talk to enemies, shooting them on sight, not taking prisoners, or other actions which break Geneva Convention Rules. In other words, by the war, the USA would become a tyrannical government with secret police, people disappearing, not adhering to universal laws, and genocidal policies. But hey, at least it would be a secret. [Answer] Just the act of stealing the technology itself would disguise it. Look at the massive efforts to steal Nazi technology after WWII. We had captured jet and rocket powered aircraft that were beyond anything we were building at the time, but no factory or tooling for them. We reverse engineered a great deal from them and then spun up multiple programs for developing a version of our own. Basically, this entailed several companies and teams being fed technical information from the captured aircraft. In one case, early experiments with jet-powered aircraft benefited from the German advances by realizing that if we swept the wings back, we could achieve much more stable flight near or at the speed of sound. The process of "digesting" the technology would necessitate developing our own home-grown programs that we could set up tooling, factories, and supply lines for. That would necessarily mean that "stolen" technology would no longer really look like the original any more than an F-86 Sabre resembles an ME-262. (Ironically, in Korea, jet fighters we developed partly based on stolen German technology went head to head with jet fighters the Russians had developed based on stolen German technology.) In other words, if I were the government, I wouldn't even worry about it. Stealing military technology is a long tradition that goes back to the dawn of time. (During the Cold War, the USSR made an art of it). [Answer] Why are you hiding this information in the first place? If anything, you should hype-up just how superior the enemy is. Look at how the Bomber/Missile/Submarine/Strategic-asset-X Gap from the Cold War was used to justify massive spending. The population was terrified of Soviet super-weapons, so they were okay with spending on things like the SDI. Instead of hiding it, propagandize the fact that you stole their technology. Make it clear that you had to steal their weapons because our own were so woefully inadequate. Blame the weak-and-cowardly political party that cut funding to weapons research. Convince your citizens to buy war bonds, or accept higher taxes to support defence spending. [Answer] **For the most part, stolen and repackaged technology is necessarily different**. The problem is that armies and their development teams use different stratagems, equipment, design goals and have own unique advantages and disadvantages. Let's say you have a prototype of a new powerful rifle. The first thing is: Can the rifle use standard ammunition of your army ? If not, then you will almost always change the caliber of the copied weapon because you won't change your complete infrastructure. Can you produce the material with the necessary strength ? If not, you must strengthen the walls (increase the weight) or lessen the amount of propellant (less penetration). Even if you have the technology, can your army pay the price ? The firing mechanism is different, the enemy had 20 years to perfect it, your team has none, but could change to a technology they have experience with. So for 100 different things your team needs to adjust the advantages to their own production and needs and the end result will be different from the original (But, as you noted, the similarities will be very conspicous). In rare cases, the technology is so overwhelmingly good in comparision that an 1:1 copy is made. One such an example is the MiG-15 engine which was slavishly copied from Rolls Royce because the Russians simply had nothing which they could have modified. In this cases look the other answers. [Answer] Well, if you think about it, in most battles nowadays, civilians aren't around to watch. So being the all-powerful United States government, you can make up fake footage and trick the citizens into simply believing a simple lie. **More Importantly** If you think about it, this "country" that you're talking about has developed this technology long before the United States figured it out - even after crashing it would take a long, long time to figure everything out. In the meantime, the other country would easily be able to figure out newer and better technology. Also, the United States only captured **1** plane. This doesn't encompass ALL of the technology that was secretly developed. [Answer] Technology has been copied and stolen and updated time and time again. At one point there was only one country with a working atomic bomb, now there's almost ten. Jet fighters, massive bombers, battleships, aircraft carriers, tanks, rocket launchers, grenades, bullets, even simply gunpowder itself were all at once point an idea or discovery that was spread and taken by the enemy because they're all tools of war. And it doesn't matter where the tool came from as long as it does it's job of killing the enemy and protecting the soldier. [Answer] In regards to the engineers on your side that design and build the equipment (because lets face it; they would be the first to realize): a good idea would be to change all of the mathematical formulas, standards and methods regarding their design. Sometimes a formula will hint at something other that what it actually does. An example of this would be that a formula for some plasma technology that has the form of a simple harmonic motion problem. (Plasma physics is chaotic in nature which excludes the simple harmonic oscillator) The engineers would be convinced by this; because while they would understand that is not what happens, it is approximately what occurs for small quantities; and that it makes sense to simplify things allowing for more intuitive understanding. Convincing the engineers in such a way, would allow them to reassure the public when asked questions about the design. ]
[Question] [ Thinking about the question about [Arcologies](https://worldbuilding.stackexchange.com/questions/19113/the-anatomy-of-arcologies/19188#19188) I was wondering using known science and even a little speculated science would it be possible to safely land a large space ship on a planet similar in size to Earth with a similar atmosphere? I'm talking about city sized space ships holding 100,000 plus people maybe even a million. I'm not asking if it would make sense to land such a craft (generally I'd say no) but would one be able to land without burning up or falling apart or killing thousands on impact? This is assuming no 'anti-gravity' generators. Also the ship was designed for space travel, So it might need to reconfigure for a landing as well... [Answer] I really *really* don't think so. Without the magic of anti-gravity, a deployable-space-arcology has to fight the gravitational pull from the planet as well as burn-off its own massive kinetic energy from orbiting/interplanetary-travel. That means it's going to need rockets. Big ones. And a load of fuel to boot. While I don't think it's plausible, I will spend the rest of this post making suggestions to make it slightly more plausible. **First, those rockets.** Lots of fuel means more weight, which means you need to more fuel to slow down that fuel. This is the classic [rocket equation](https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation). You can reduce the amount of fuel needed by *blasting it out faster*. This is difficult to do with chemical rockets - people have engineered them to their upper limits already. Higher thrusts can be made from [various types](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)) of [nuclear](https://en.wikipedia.org/wiki/NERVA) and [plasma](https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket) thrusters. **ACME Arcology. Just add water.** Secondly, add agriculture, water, and (most importantly) people separately. Living things are fragile and squishy. Water is sturdy, but adds weight to the system. This allows the landing to be a little less gentle. Also, the heat from re-entry and your rockets won't cook everyone. **Some assembly required.** Finally, build the arcology in [kit-form](http://cdn.visualnews.com/wp-content/uploads/2012/08/Austin-Martin-DBR-Full-sized-Model-Kit-1.jpeg). Deploying smaller sections and putting it all together at the destination is probably an easier task. The larger the space ship, the more care you need to put into making sure the stresses and strains across the ship are balanced. This is most important when landing - otherwise it will break apart an scatter itself across the surface. [Answer] **Space Elevator:** Another possibility is either building (or using an existing) space elevator to lower yourself down slowly. The elevator would need to be strong enough to hold the ship, and the counterweight would need to be heavier. Both are difficult to pull off, but probably easier than battling the tyranny of the rocket equation for something this big. If the ship is capable of interstellar flight a space elevator shouldn't be too unrealistic. If it's an uninhabited planet, the ship can carry the cable(s) with it, and then drag a big asteroid into orbit for the counterweight. Then a smaller crew lands and anchors the cable. Finally, the big ship hooks itself up and slowly lowers itself down, with the counterweight keeping it from falling. Lowering the ship down in modular pieces should make all of this much easier too. [Answer] you added the tag reality check, so I will be honnest, you don't want to consider that option. Large space ships shouldn't be meant to land, that would be as dumb as it can go. The power of the engines and the amount of energy necessary to move such a ship near a planet'surface (let alone take off from it !) is astonishing. Moreover, you would also need to have these ships designed to resist both their entry into the atmosphere **and their own weight**. To avoid these great hindrances, a more logical way is to build space ships in orbital shipyards - bonus points if the yard orbits a moon - so that you have almost no gravity to deal with. The ships are then used in space and brought in planet orbits from which people travel to and from the planets with transport modules, space elevators, whatever. The key here is not that it wouldn't be possible to your civilization, it's that it wouldn't be an excuse to be that bad at engineering. The same way, colonization ships shouldn't land either. The settlers in it should leave the ship with landing modules. This allow these modules to also be colonization modules fitting various usages like housing, oxygen and water production, defence, whatever... while the ship orbits the planet and maybe handles the teraformation business if needed. [Answer] A modular approach may provide at least a partial solution. It should be possible to break-down a significant portion of the ship into manageable sized chunks that could be parachuted or otherwise flown down to the planets surface where they could be reassembled. Life support systems could be easily included in the necessary modules. Those components of the ship which could not be landed safely (e.g., the ship's engines) could then remain in orbit. Modular components could include the parts necessary to build power supplies for the terrestrial construction. For example, imagine a disc shaped ship where modular components are assembled into the outer rings of the disc, while non-modular components are located at the disc's core. [Answer] Closest analog for your question would be, what would it take to safely deorbit an asteroid large enough to cause a continental extinction? To do so will require reducing your arcology's speed from 20k mph to 0mph and your altitude from LEO to 0 AGL. As we have seen with SpaceX's Falcon 9, this is a difficult process to pull off. If you equipped [Project Orion](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) "Project Orion")-style propulsion on your ship, that could give you the delta v required to skip the firey doom of reentry and just drop out of orbit. (Added benefit of this approach is that PO craft actually get better the bigger they are.) You would need a different method of actually landing because PO propulsion, if used for landing, would make the landing area into a nuclear wasteland. Not so good. Use a lifting body design while landing. Or, sacrifice the landing zone, use the pusher plate as your landing gear then move the arcology to a new area. If for some reason using nuclear propulsion isn't allowed, conventional reentry is going to be the biggest problem. Controlling your descent profile, preventing tumbling, heat dissipation, transition to flight, landing, properly stowing cargo to prevent damage... There's so much that can go wrong. The mathematics and physics knowledge required to pull this off just boggles my mind. You don't have to use fueled rockets to land your arcology, do what the space shuttle does and use wings to convert to an air steerable craft. Alternative to landing one giant arcology: Build lots of smaller ones that can be assembled once they land. [Answer] ## YES! Deorbiting a 1 million tonne vehicle from LEO generates 6 petawatts of energy. This can safely be dissipated if your spacecraft has 20 liters of water per person (100,000 people) to evaporate during landing. **Challenge #1:** It has to hold it's own weight on earths gravity and be able to "withstand deceleration". Googling 'heaviest skyscrapre' led me to the fact that we can build self-supporting structures that mass in the hundreds of thousands of tonnes. I found figures like 700,000 tonnes. Needless to say, this is on the edge of plausible for your predicted 100,000 people (7 tonnes of life support + accommodation + hull + food per person). It doesn't leave a lot of overhead though. As a side note, in the 1960's, they were throwing around ideas for spacecraft weighing in excess of a million tonnes (Project Orion). Let's assume it's engine can accelerate it at 1G, then to take off/land from the surface of earth, the whole structure has to be able to withstand 2G of acceleration. Throw in some vibration and factor of safety, and you probably want to rate it a fair bit higher. This is no small feat, as most skyscrapers are designed for relatively static loading situations. I don't think any skyscraper would do well being dropped even a few meters, so your landing thrusters had better be able to set it down really really gently. **Challenge #2:** All that kinetic energy. Your spacecraft is in orbit and has to shed velocity to land. If you have super powerful engines and can both decelerate it before hitting the atmosphere, and lower it slowly through the atmosphere then this isn't a problem. If you plan on using aerobraking you're going to need a super super massive heatshield. LEO is 2-4km per second. Given a 1 million tonne vehicle you have some odd 4 petajoules of kinetic energy. While descending it will convert another petajoule or two of gravitational energy into kinetic energy. The descent time of the space shuttle shuttle was half an hour from 'entering' the atmosphere to landing. In this timeframe the city-spaceships heatshield has to deal with an average thermal load of over about three Terawatts. (Way more than a delorean). This level of power is on the same order of magnitude as [USA consumes continually (average over 2005)](https://en.wikipedia.org/wiki/Orders_of_magnitude_(power)#Terawatt_.281012_watts.29). To avoid needing to dissipate this energy with rockets, we can aerobrake and evaporate water. Evaporating water consumes 2Mj per kg of water evaporated, so if we pump water through vents in the front of the vehicle to absorb the heat, you will need about two million litres of water. Because you have 100,000 people on board, you will be carrying a lot of water: if you have 20 liters per person then you should have enough. Of course, designing the hydraulic system to dump 20,000,000 liters of water through the front of your vehicle is no easy feat. If you remember the comparison to the USA energy consumption, this means you could get the USA to boil a 20,000,000 litre kettle! --- So the landing process of your craft will be: 1. Drop orbital velocity to dip into earths atmosphere 2. Burn off as much energy as possible by dumping water out the front 3. Fire up some super powerful thrusters to slow your ship down for final descent. 4. Land [Answer] If you want to not burn up you'll need to come into the atmosphere slowly, thus you'd orbit the planet, then slowly decrease your orbital velocity. If you want to not crash on impact and obliterate the planet, then you'll need to land slowly. The two ways we currently have of solving this are: gliding in onto a runway like a **plane**, and drifting down with a **parachute**. So I think this question boils down to: Is it possible to have an airplane the size of a city? and/or is it possible to have a parachute that could slow down a city-sized object? Assuming we have some futuristic/exotic/light-weight materials, I think either thing would be possible. *Edit 1:* A third option would be a giant, sturdy **space elevator**. The ship would need to connect to the elevator and then very slowly lower itself down the elevator. The downside to this is that it requires a lot of infrastructure on the planet already and the ship would likely only be able to land in that one location. *Edit 2:* Another option that Samuel brought up is using **thrust via rocket burns**, like Falcon 9. [This Stackexchange Q&A](https://space.stackexchange.com/questions/7718/why-would-spacex-not-use-parachutes-for-the-final-descent-of-the-first-stage) has a great discussion about why Falcon 9 uses burns, and why parachutes are not ideal, largely due to less descent control. [In this Q&A with Elon Musk ("Why not wings")](http://shitelonsays.com/transcript/elon-musk-at-mits-aeroastro-centennial-part-1-of-6-2014-10-24) he mentions that part of the reason for using a thrust solution is for R&D for Mars, and that half of the velocity is negated by the landing gear acting as flaps. Ultimately I think the best solution would make use of wings and flaps for slowing down (see the [Space Shuttle](https://www.nasa.gov/mission_pages/shuttle/launch/landing101.html), the heaviest thing we've landed), and thrusters for final landing accuracy because there's no runway for a massive ship, and you probably want to avoid causing a tsunami. [Answer] In principle, I see no reason why a reentry with a heat shield and a landing using rockets would not scale up. Most answers suggest unusual and exotic ways of landing the thing, but it's not necessarily needed. At some point you would run into issues of plausible material strength, but I suspect you're not quite there yet with a city-sized ship. That said... While you could theoretically land a very large spacecraft, it would likely have to be designed for it from the start. It's going to need a massive heat shield, and even more significantly its structure is going to need to take the forces of a multi-g deceleration, which is likely not a standard feature of a spacegoing cityship. And though active control could help to a degree, it'd have to be designed to at least not be aggressively unstable in atmosphere. Do take care when landing. Those thrusters are going to be big enough to vaporize anything nearby. [Answer] This question was faced for real in the 1960's, with man's first landing on another celestial body. The original thinking, known as earth orbit rendezvous, had a complete spaceship landing on the moon, and returning directly to earth. Such a ship turned out to be quite large. However, an engineer, Tom Dolan, realized that it was wasteful to take the fully equipped spacecraft to the surface with all sorts of things it didn't need to land on the moon: the return fuel, heat shield for reentry, etc... instead, he proposed a smaller, lighter lander with just the bare essentials to land on the moon. This approach was called lunar orbit rendezvous, because the small spacecraft would have to rendezvous with the main spacecraft on the moon. In the end, lunar orbit rendezvous was chosen, because a complete moon mission could be carried out with one Saturn V launch. The much larger earth orbit rendezvous ship would have to be assembled in orbit from several launches. To get back to your actual question - it's possible to land an entire spacecraft on an earth like planet, but it would have far greater mass than pure space traveling ship to withstand the gravity, and thus need a lot more energy to move around. Just like Apollo, you'd find it far more economical to build a smaller ship for the purpose of penetrating an atmosphere and landing in gravity, and use that instead. [Answer] In theory you can land *anything* if it's strong enough and you have enough distribution of force that you don't get component failures, so yeah you could land an arcology scale starship *if* it was built for it. You'd most likely make it from a diamond mono-crystal (sorry no you wouldn't, see [here](https://worldbuilding.stackexchange.com/questions/91045/diamond-as-a-building-material) for the why). You'd probably want to land it in water because the thermal input from the landing thrusters is going to be ridiculous, even landing in the sea you're probably going to sterilise continental scale areas of land around about and possibly upset the global ecology wholesale, at least for a while. If you put it down on the ground you'd convert vast swaths of land into deep pools of glass. What you're not going to want to do is try and go outside for a the first few... I'm not sure... days certainly, probably weeks or months, possibly even years while the weather etc... settled back down. [Answer] I assume this is a 'colonise a world' scenario? You probably don't want to land it as one big ship, even if the ship can withstand it. If you want to permanently land such a ship and 'install' it into the world, it'll almost certainly want to be reconfigured to fit the landscape of the world. You can't just put down landing gear and land it as one big ship, as you'll find it rapidly sinks into the ground due to the pressure (google to see what's happening to San Francisco's Millennium Tower due to incorrect foundations). So – after landing an engineering crew to prep the ground – you'll want to land it in sections, and rearrange them as they land to fit the terrain and spread the weight correctly over your foundations. [Answer] Landing a craft on a planet requires braking. Even if you start out at zero velocity relative to the planet, you have to partially counter the planets acceleration due to gravity or you will do all of your deceleration at once (a less than ideal situation). The two main ways of decelerating while landing on a planet with an atmosphere are thrust based braking and atmospheric braking. Thrust based braking requires enormous amounts of fuel. It isn't like a Falcon 9 coming back down after launch because you still have the payload.To launch a rocket, it takes 15 to 40 times the weight of the vehicle and payload. When coming down, there will be some atmosphere braking even of that isn't the main means of deceleration. So, lets be generous and say that it takes 10 times the weight of the vehicle (including crew and payload) to safely land the ship. That is a lot of fuel to still have left at the end of the journey. That much force will require the vehicle to be heavier to deal with that stress (adding more fuel). A narrow base like a normal rocket would require a lot of energy to be generated from a very small area (relative to the mass of the vehicle). A flatter, more spread out shape, like a disk would allow the thrust to be spread more evenly but would greatly increase the structural requirements of the vehicle. It is also likely that wherever the ship lands will be a barren, cooked, hellscape. Aerobraking (atmosphere braking) is possible but the engineering of that (heat and stress) would be massive. Creating a set of parachutes to cover an object that massive would be daunting. For one thing the object would alter the air flow around it making groups of small parachutes difficult to design. A single chute that is massive enough to ignore the airflow around the ship would probably have to be made out of some sort of unobtanium. If the vehicle is coming in "hot" instead of braking to "at rest" relative to the planet, it will require a heat shield to slow to a speed that the parachute can operate (and not cause the initial tug of the chute to splat everyone on board). This is even more weight that has to be added. It also means that the vehicle should be designed with some sort of symmetry or it will start to tumble from the uneven air pressure. Another method of aerobraking is the lifting body. This will fly or glide down. The trouble is that the less aerodynamic it is, the faster it has to go and the longer flat spot you need to find to land on (I recommend water landing for this). The more aerodynamic it is, the more wing you have hanging out there to get ripped or burned off during initial aerobraking (more structure, more mass). Some sort of combination of all of these might be the best bet. It is also almost certain that any such large vehicle that lands will not be taking off. [Answer] See James Blish's "Cities in Flight" books. Earth discovers a way to neutralize gravity in a spherical region. This allows whole cities to take to the stars. (It also can hold an atmosphere. Cities that are built on bedrock can be equipped to fly. Blish plays fast and loose with the science. (Most of his fiction is more exploring topics of strange social conventions. No rivets.) ]
[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/223344/edit). Closed 1 year ago. The community reviewed whether to reopen this question 1 year ago and left it closed: > > Original close reason(s) were not resolved > > > [Improve this question](/posts/223344/edit) I'm working on a sandbox astrophysics, economics and military simulation generator (there is no defined setting but I try to use real and hypothesized science for the most part) where different types of systems have various economic and/or military uses. But I'm struggling to conceive of any for stellar black holes, beyond being natural travel impediments and/or slingshots. Anything involving trade, resources or conflict would be really welcome as an idea. Q: Are Black Holes Military & Economic Assets ? [Answer] [Gravitational time dilation](https://en.wikipedia.org/wiki/Gravitational_time_dilation) may have some useful applications. The closer you are to the black hole, the stronger you experience its gravity, and stronger gravity means you experience less time than people further away from the black hole. Of course, all gravitational masses cause time dilation, but black holes are especially small compared to other equivalent masses, so you can get much closer to them, and so the amount of time dilation can be much greater. For example, if you have things which are used very rarely but require expensive ongoing maintenance - e.g. nuclear weapons - then you can put them near a black hole, and they will degrade slower relative to your frame of reference. That means lower maintenance costs. You might also have some group of people who want to permanently live close to the black hole, so that they experience time slower and are able to benefit from a faster rate of technological progress from the outside world. This would mainly be people rich enough that they don't have to work to earn a living (as time dilation would proportionally reduce the value of their labour to people away from the black hole), but perhaps also include people with uncurable diseases who want to survive "longer" for a cure to be found. [Answer] Behold, the [Penrose Process](https://en.wikipedia.org/wiki/Penrose_process). Shoot a chunk of matter into the the black hole's [ergosphere](https://en.wikipedia.org/wiki/Ergosphere), and then split said chunk of matter into two parts right as it crosses the border. One part escapes the ergosphere. One is pulled in. The part that escapes has more energy than the initial chunk of matter went in with. In other words, this lets you harvest the black hole's rotational energy. [Answer] **Lighthouse** [![saggy](https://i.stack.imgur.com/MjNuVm.png)](https://i.stack.imgur.com/MjNuVm.png) <https://www.newscientist.com/article/2191429-our-galaxys-supermassive-black-hole-may-be-spewing-matter-right-at-us/> Some black holes are energetic radiation sources; depicted is Sagitarrius A aka "Saggy" at the center of our galaxy. Your people use their black hole with its characteristic electromagnetic visibility as a beacon, Lighthouse of Alexandria style. --- A more esoteric use would be to pan the emissions for special particles. Autonomous drones arranged according to the same principles of a Dyson Sphere pan the emissions like prospectors pan for gold. Among the energetic protons and other common things are very uncommon things - super heavy nuclei, negative matter, antimatter and other weird matter forms which were forged in the hole and somehow wound up spewed into space. [Answer] ## Harvesting energy Hawking radiation is a theorized form of radiation generated by black holes. You can theoretically harvest this energy. Not a fan of super theoretical ideas? Well there are plenty of other ways. You can shoot some stuff in, have the black hole speed it it up. And you now have some power. You can do All sorts of other fancy stuff with it, point is you can get energy from a black hole, it can basically be a power plant. [Answer] As an alternative to my other answer, you could construct a [black hole bomb](https://en.wikipedia.org/wiki/Black_hole_bomb). Surround a rotating black hole with mirrors and shoot a laser into it. Over time, the laser is sped up as the black hole's gravity acts on it, but it can't leave - instead, it hits a mirror and is then reflected back towards the black hole, which speeds it up again, and bounces it off a mirror again, and so on and so forth. Eventually, this laser is going to be packing a *lot* of energy - and, if you remove the mirror where it's going to hit next, it escapes. This can serve as either a power source or a weapon, depending on whether you aim it at a set of collectors or somebody you ***REALLY*** don't like. [Answer] if it has an accretion disk it's a source of cosmic rays and relativistic particles, not a healthy neighbourhood. they're good at turning mass into energy. But regular stars do that too if less efficiently, the stars are less deadly. maybe you can think up a way to use them as gravity wave transmitters. [Answer] **Completely fictional, and just for fun...** * Let's assume that a black hole exists perpendicular to the orbital plane of a solar system. It's far enough away to not threaten the solar system, but close enough to suspend disbelief for this next part. * Let's assume a traditional mono-molecular can't-be-broken-in-heaven-or-on-earth wire. And it's really long. * Let's assume an end of the wire is connected to a reasonably indestructible golf ball. * Let's assume the other end of the wire is attached to a piezo-electric generator on one of the orbiting planets and mounted on some whomping foundation blocks that are well attached to bedrock. And then we fly it as close to the black hole as we can and set the hummer free! Once the wire tightens, you'd have free power for the whole planet forever. The closer the golf ball gets to the black hole, the stronger the pull on the wire, the more power you get. *Besides, you can have stories like, "Commander, why can I see the bottom-half of the ship over there to our left? What'd we hit?" Given the tension on the wire, you might have a planet be sliced in half like a peach and not really know it happened.* [Answer] You could use them to put people in stasis. If you have a way of accelerating one, you can use it to drag a spaceship behind it without the spaceship experiencing local g-forces. ]
[Question] [ Okay, I know I'm posting a really implausible question, please be understanding.... Many years ago, a powerful mage went mad (occupational hazard; one *does* encounter eldritch horrors and reality-altering magic when one is a powerful mage responsible for keeping the world safe), harnessed the powers of the eldritch horrors he slain, and corrupted the world's mana, permanently altering our *food.* Each and every single food you can think of-Black Forest cake, sour gummi worms, hardboiled eggs, carrots-has gained adorable eyes, simple mouths, and primitive limbs (for examples of creatures with these traits, look at Kirby or Shopkins, the inspiration for this question). Furthermore, each of these food items has gained both unique personalities and 'cultural' traits, along with the ability to speak (which comes with rudimentary-think caveman-intelligence). Food heals or reproduces by expending energy, which comes from the corrupted mana of the planet itself. For example, two hamburgers, side by side, release a bolt of energy that collides between them and *poof!* A baby-size hamburger appears. The two "parents" then have halved energy and must wait a certain amount of time before they can have another "child." Furthermore, food items can merge. For example, flour, eggs, sugar, butter, and milk fuse into a cake (and without baking soda, since I just can't count that as actual food...). This cake will have the combined intelligence and traits of the ingredients that came together to make it, making it a superfood (the food equivalent of superhuman). Each food has instinctive awareness of merging and reproduction from the get-go, but they can't do either until they mature. This takes the same amount of time as recharging for a "parent." Additionally, food does not need to eat and heals damage (or loss of mass, like when a cake is cut into slices) over time. One example would be that candy tends to dissolve in water; so if living candy is exposed to water, and isn't completely dissolved, it can gradually restore mass. Since energy is going into regeneration, the candy will be weaker and slower during this time. This principle makes any cold food (like ice cream) weak but generally unmelting when exposed to heat (say, room temperature, or a hot car, NOT a blowtorch). Finally, food can grow (or heal) by absorbing other members of their kind or their ingredients; carrots can grow by absorbing carrots, while cakes have the alternate option of absorbing flour, eggs, butter, sugar, or milk to grow. Growing causes a proportional increase in intelligence. As for when animal/plant matter becomes food for the purposes of this question: as soon as fruit is fully formed, it becomes food and comes off. Once vegetables (like a carrot or head of lettuce) are fully formed, they become food. Animal carcasses and so forth are not meat until they are prepared; for birds, this means being plucked, beheaded, and cooked, for snails and insects, this means being cooked, and for fish, they have to be either cooked, made into sushi, or cooked and canned (as for sardines). For those interested (like Nzall), bulk food LIFE is simple. Take a scoop from a bag of flour, and that scoop is alive as well, but less powerful and intelligent than the entire bag. The bag then has a slight dip in power and intelligence. My question is simple but complex: **How Will This Impact Mankind's Interaction With Food?** As always I appreciate your input, and your feedback. If this question is too opinion-based, or needs additional information, I would greatly appreciate advice on fixing it. EDIT: Thanks everyone, your answers were all very helpful and I'll be using pieces of each and every one. **EDIT 2: Clarification** 1. Yes, the food feels pain-*emotional* pain, a sense of loss, whenever they lose part of themself. Exposing food to it's weakness-like heat for ice cream or water for bread-causes it physical and emotional anguish. 2. Where is the energy over time coming from? Eldritch monstrosities, things like Chthulhu, have an Aura of Discord. They generate chaotic (AKA magical) energy that the living food draws off of. [Answer] **Food cannot be stored in the home.** So everything we eat is alive? Well guess what, that's already true. The cow you had for dinner was alive! Okay I admit it's not quite the same. But now the world has changed so, not only does the cow in the meadow walk and talk, but also the steak on you plate was still walking and talking as you gobbled it down. The same for the milk and eggs that would be in your fridge and the fruit in the fruit bowl. I say *would* because fridges and fruit bowls no longer exist. Food cannot be stored in the home any easier than storing a live cow. All food must be treated as though it was livestock, in the age before meat preservation was invented. That means it cannot be stored and must be eaten immediately after it is *slaughtered*. Meaning if you want some meat you go to the market square where someone has just slaughtered an animal, with a mind to immediately butchering and selling off the pieces for consumption *that day*. That means most meals are now eaten outside the home in large facilities. I presume the crops and livestock behave same as normal. It is transported from the fields to special facilities and only at the last second is it rendered into *food*. Then it is prepared in industrial size pressure cookers, with reinforced walls to prevent the ingredients escaping. Then it is served and eaten immediately. [Answer] **Breaking News!! PETA finally loses it and declares war on mankind, starves to death before doing anything.** Okay, so that may be pushing it... they'd probably starve before declaring war. I don't think the overall relationship between us and our food would change all that much just because food is cute now (have you seen a baby cow? cute as can be... [also delicious apparently](https://en.wikipedia.org/wiki/Veal), can't really say as I've never had it to my knowledge). There would inevitably be those who now shy away from cooking for themselves and end up contributing to the sudden restaurant boom. The most major impact this event will have is perhaps a vast increase in price due to the inadvertent creation of perpetual-motion/self-sustaining food. Buy it once and so long as you don't eat it all? Boom, food for life. So that pretty much ends global hunger. Oh, and the vast majority of farmers/ranchers/etc... going out of business because nobody needs *extra* food now. Though, with food now able to reproduce, maybe they'll all have new jobs as food wranglers. Imagine trying to corral a herd of tacos. [Answer] <https://en.wikipedia.org/wiki/The_Magic_Pudding> [![magic pudding](https://i.stack.imgur.com/UPwsr.jpg)](https://i.stack.imgur.com/UPwsr.jpg) > > Wanting to see the world and unable to live with his uncle anymore, > Bunyip Bluegum the koala sets out on his travels, taking only a > walking stick. At about lunchtime, feeling more than slightly peckish, > he meets Bill Barnacle the sailor and Sam Sawnoff the penguin who are > eating a pudding. The pudding is a magic one which, no matter how much > one eats it, always reforms into a whole pudding again. He is called > Albert, has thin arms and legs and is a bad-tempered, ill-mannered > so-and-so into the bargain. His only pleasure is being eaten and on > his insistence, Bill and Sam invite Bunyip to join them for lunch. > > > The interactions will be one of songs (many), battling persons who come to claim delectable living food, racing to catch the fleet footed food as it tries to run away (out of principle; it likes to be eaten) and also three-stooges style comedic violence. > > One of the great advantages of being a professional Puddin'-owner,' > said Sam Sawnoff, 'is that songs at breakfast are always encouraged. > None of the ordinary breakfast rules, such as scowling while eating, > and saying the porridge is as stiff as glue and the eggs are as tough > as leather, are observed. Instead, songs, roars of laughter, and > boisterous jests are the order of the day. For example, this sort of > thing,' added Sam, doing a rapid back-flap and landing with a thump on > Bill's head. As Bill was unprepared for this act of boisterous humour, > his face was pushed into the Puddin' with great violence, and the > gravy was splashed in his eye. > > > <http://www.gutenberg.org/files/23625/23625-h/23625-h.htm> [Answer] ## There will be war against food If the food have primitive inteligence, it would try to preserve itself from being eaten, spoiled or dissolved (candy would try to climb out from puddle, for example.) Home food would try to escape to wild, to keep itself alive. And cake can simply absorb berries to became berry-cake, so it would survive there rather than be eaten by wild food. And it would increase its inteligency too. There is also lot of food in wild already, just think of fruits, insects, honey ... and if it have ability to multiply without eating, it would eventually fill all the space and then start spreading to human-occupied places, at least forced by pressure of the mass itself. (And with capability of self-healing it would not degraded to soil, but lives heathy forever.) But we have already too much of food in storages, gardens etc. etc. so there would be conflicts much earlier, when loose food start massively overtaking cities, villages and such. The overfoodation (= overpopulation of food) will grow exponentially and unregulated would cover Earth in layers after layers of food, until the monstrosity would collapsed into itself just by gravity force. So humans would be forced to solve that thread by force and long lasting fight over all the globe. Also it could destroy the ecosystem easily - cooked rice does not dissolve in watter, so it would be able hunt sea for raw fish and octopuses and sharks to create sushi, sashimi and all kind of such superfood. (If flour and milk and eggs is able mix itself and cook to cake, then rice should be able mix itself with fish and make sushi. Also note, that "living suschi" <https://en.wikipedia.org/wiki/Ikizukuri> is made of still living seafood, therefore it could came "superfood of rice" ) --- ## Foodibalism It is well documented canibalism ( <https://en.wikipedia.org/wiki/Human_cannibalism> ) in times of famine at many times, some only 90 years old ( <https://en.wikipedia.org/wiki/Holodomor#Cannibalism> ). So regardless its eyes, limbs, inteligecy and ability to argue, people will eat the food anyway - as there will be no other food, than food - and it is more simple eat protesting cake, than to kill a fellow human, cook it and then eat protesting coocked fellow human. [Answer] **"How will this impact mankind's interaction with food?"** In many, many ways. Given that food is now intelligent, it will presumably begin to actively avoid permanent destruction. Especially so given that they possess ape-like (caveman) intelligence. I don't know how motile a living cake is, but we could see foods attempting to flee distribution centers, pantries, etc. And they may decide to form some sort of army or active armed resistance to inflict casualties and fatalities on the human population (aka their predators). This could very well end up a serious threat, given that food itself is undying, regenerates, and does not need to ingest energy in the way ordinary living things do. A kitchen or pantry will almost certainly turn into a sort of prison but for food. Where the goal is no longer to preserve and organize meals, but simply to keep them contained. This is of course a losing proposition: The biggest issue is one of physics. Two food items can 'zap' another food item of similar type and form into existence. This expends some sort of energy within the food items. But the food items can and will regenerate this energy. Where, exactly, does this energy come from? The food items are, effectively, creating mass out of a regenerating nothing. They can use this ability to burst through any barrier, overrun any population center, turn our planet into some horrific cakeworld, etc. Or, if we could reason with or permanently subdue them, we could use this ability to generate an infinity of almost any element (or, you know, food) one could reasonably expect to find in food, such as Hydrogen or Potassium. A cake covered in platinum shavings is still a cake, is it not? All in all, things would get incredibly strange incredibly quickly. ]
[Question] [ In my world, a species of vertically challenged humanoids spreads out from their island homelands to the wider world, entering the interspecies race for global dominance. Now, this species of humanoids are quite disadvantaged in a straight fight against any other, being the smallest at but 1.1 meters tall, however, this in reality is a contest not of might, but niche effectiveness. You see, hominids are all more or less generalist / opportunistic hunters - animals that are broadly omnivorous (eating berries, seeds, certain foliage, etc) and broadly predatory, hunting game of any size. Hominids were very, very, good at this strategy, which allowed them to spread anywhere such calorie sources were available (i.e. everywhere on Gaia's green earth). That being said, there exists an ecological concept called Competitive Exclusion Principal, where when two species occupy the same niche in the same area, they compete, and whichever species exploits the niche most effectively displaced the other. Now, generalist is truly a contest of "who can exploit the most calories in a given area" and, given a more diverse food set, the most general generalist wins. Here in lies the most ultimate prize in untapped calories for a hominid — grass (and leaves). Very few generalist exploit this nigh-omnipresent food source\*, and the sheer amount of it could keep a hominid fat when most others would starve, allowing them greater population and a greater range than any other, along with an easy way to outcompete its competition. However, two problems abound: * grass (and leaves) are tough and wear on teeth * grass (and leaves) are difficult to break down, making the energy spent in digestion take up most of the calories contained in the grass, blunting the competitive edge Seeing as how even the best grazers and browsers have, at best, middling solutions for these issue given millions of years of evolution, a purely evolutionary solution is unrealistic. So now we turn to the human ability to develop skills and technique. **What technique could be implemented to release the most calories from grass and leaves?** --- *Note: Yes, I am aware that cereals and corn count as grass, but human consumed varieties are far fewer and are more work and resource intensive to produce* [Answer] # Cooking Cooking plant materials takes care of the problem of the grasses being too hard on our teeth or digestive systems. In many cases, breaking down the fibers and so forth will release more calories and micronutrients. Some of this can also be done with fermentation. Once a species has the ability to make and control fire, and to make a few tools such as clay pots, cooking is an easy task, along with gathering. Eating and digesting are faster, so overall it doesn't take more time in a society large enough to have specialists (pot makers, fire tenders, wood or dung gatherers, etc). The problem is that most grasses (aside from the grain portion and a few exceptions like sugarcane) are not suitable human food. They don't provide enough nutrition for hominids in general. The only ways to change that are: * Evolution of the species to be able to get large portions of its calories from grass. This takes a *very* long time. * Evolution of the grass to meet the hominid's needs. This also takes a lot of time and requires evolutionary pressure that may not be present. * Selective breeding of the grasses. Not as long a time, a few centuries, maybe longer for the grass family. * Agriculture. Gathering and planting seeds (or tubers) of high-nutrition plants so they displace the low-nutrition grasses. * Using a method you've dismissed: Eating animals (or their milk) that have digested the grass for you. In other words, agriculture. * Or the other method you dismissed: Harvesting the nutritious portion of the grass, the grain (or the stalk juice, in the case of sugarcane). Cooking and sprouting both increase digestibility. * Fermentation. This will produce the calories you want, in an easy to digest form. As alcohol. But it's not really the best way to get most of one's calories. And you need to mostly use the grain portion. (You can also ferment the stalks/leaves to break them down without heat.) Consider this a frame challenge. To use skills and technique, you must accept use of skills and technique. If you are truly looking to be quicker than evolution and to use "the human ability to develop skills and technique" your answers are: * Agriculture * Animal husbandry * Fire/cooking/fermentation/other food prep techniques [Answer] None, in the long term. There were hominids who lived this way, the grasslands dried up or predators expanded or something else happened and they no longer exist. The reason hominids are so widespread is precisely because of being adaptable. The [grass eating monkeys](https://www.nationalgeographic.com/magazine/2017/04/gelada-monkeys-grass-eating-guassa-ethiopia-bleeding-heart/) alive today are only able to exist in a tiny area because it's not easy to get at. There are zero apes living solely off grass. Because they're not competing a niche against genaralist hominids, they're competing a niche against wild cattle and other bigger, faster, more suited animals. They cannot outrun predators or fight them. If they had the size and strength of Gorillas it might be different. Gorillas just need to eat, there isn't usually a need for speed, they're strong enough to tear a predator limb from limb. In later times it would be impossible because you're not competing with generalist hominids who don't consume grass, because they do consume grass via their animals. You'd be a pest eating livestock food. Nasty things happen when animals or even people get in the way of farmers and herdsmen. The Bush people of Africa would be an example. [Answer] **Hominids have other mammals eat the grass for them, and in return keep these animals safe and fed.** [![masai with cattle](https://i.stack.imgur.com/37xdO.png)](https://i.stack.imgur.com/37xdO.png) [source](https://www.pinterest.com/pin/544583779924493837/?lp=true) It requires a lot of adaptations to efficiently thrive on a grass diet. Starting from a hominid body plan, in the short to intermediate term a grass diet means a suboptimal result - something like a panda, or Gigantopithecus. But hominids are good at planning, scheming, planned aggression, remembering and cooperation. Intelligence is not adaptive for a diet of grass, but things that live on a diet of grass can benefit by their association with a human that can use his or her intelligence of behalf of the grazers. Thus: pastoralism. The human shepherd or cowherd manages the herd of herbivores - anticipating their needs and moving them accordingly and protecting them from predation. With human help, the domestic grazers handily outcompete their wild relatives. In exchange the herbivores transform the grass into their meat and milk and support the humans with these transformed grass calories. This is not science fiction. [Answer] Isn't wheat a grass? Along with rice, corn, oats, barley - even pineapple? Wheatgrass juice has 7 calories per ounce [$\simeq 1\cdot10^6 \text{J/kg}$] so to get 2000 calories [$2000~\text{kcal} \simeq 8.4\cdot10^6~\text{J}$] that would be 2.2 gallons per day [$\simeq 8.4~\text{kg/day}$] (daily recommended by believers is just 2 ounces [$60~\text{g}$]). [Answer] 'What technique could be implemented to release the most calories from grass and leaves?' There are two proven methods. One is fermentation. The second is bacterial action to break down the cellulose. Farmers use silage techniques (non-aerobic bacteria) to break down grasses for long-term storage. Perhaps you might like to look at fermenting silage into a drink or a mash? There is enough protein in grass to sustain life, the trick is to unlock it from he cellulose. Grass will break down in a compost heap, the trick is to not keep it all bunched together, but mixing it in with other organics. If you want to hand-wave away the details, for a fictional story imagining that they have perfected a method of composting grass using silage techniques, and then fermenting the product into a mash, seems plausible enough. [Answer] Humans, as they are, may harvest the grasses that sprout after a rainfall. This is close enough to [sprouting](https://en.m.wikipedia.org/wiki/Sprouting). The disadvantage is limitation to some time of the year. If they began farming, then it is possible to extend that period. Also, pay attention to the "health concerns" paragraph in the link. The humans would still need additional food sources. The changes needed for a human to feed on grass may be too much of a leap forward within your timeframe. [Answer] **There isn't one** The problem is not processing the grass, it is how little nutrition grass and leaves contain compared to how much a hominid needs. Hominids have large brain, large brains demand a lot of calories. 1/3rd of all the calories a human eats goes to just support a 3lb brain. So just to start off hominids need more calories than a different animal of the same size. **Even if you solve the problem they will never eat enough**. Leaves has very few calories, even leaves humans have bred for consumption have pathetically little calories. cabbage (a high calorie leaf) for instance has 0.1-0.2 calories per gram, compare a peanut 6 calories per gram. this is why grazers/browsers have to eat a LOT of grass. An active human needs about 3000kcal per day, that's about 50-60 lbs of foliage per day (compared to the 4-5lbs of food humans normally eat). Lets say they have manage to extract every iota of nutrition from the foliage and get twice its value, thats still 25-30lbs of grass a day, your creatures are going to do nothing but eat just to get enough food into their gut, and that is assuming you solve the digestibility problem. **Why you won't solve the problem**. The problem with leaves is they are low in calories and it is hard to extract, because most of the caloric value is in cellulose, fiber. The only animals that can digest cellulose do so by using gut bacteria to ferment the cellulose, this however is slow and costs calories that the gut bacteria use for themselves. They are essentially secondary consumers who store the primary consumers inside. The other solution is just to eat huge quantities and ignore the fiber, this means they are eating even more than before. Both require the fiber to broken down in to as small of pieces as possible, this is why animals spend hours chewing up foliage before digesting it. Mechanical processing could replace this but it will still take a great deal of time. **So lets take the perfect scenario for your creature**. Your creatures collect 100lbs of foliage to eat maybe an hour or two of time, are now spending dozens of hours grinding up (querns took hours to grind small quantities of wheat you are grinding a hundred pounds of leaves), then ferment it in casks or just eat more, either way you have losses, hence doubling how much they have to eat (which is probably generous). Then they cook it to free up anything that is left and make it easier to extract, maybe an hour or two. Then they actually have to eat a hundred of pounds of the porridge/slurry to get enough calories which will also take hours. Your creature has just spend the entire day doing nothing but preparing and eating its food. It still needs 8 hours of sleep. that's more time than there is in a day. Worse every free hour they have is spent making querns and casks for food. Compare the human hunter gatherer that is spending 3-5 hours per day feeding itself and has the rest of the time to do other things. **Making the animal smaller makes it even worse** since its gut has to be smaller, and it's body is less efficient with its calories (square cubed law in play). The size of the gut determines how much they get out of their food. Hominids have short guts to begin with since they eat high value foods, so losses are less of an issue, but your creatures need every calorie. Even if it was human sized it would need to have a much large gut than a human, meaning the rest of it needs to be smaller to keep its mass down. This is why bulk feeder are usually very large, it allows for a huge gut and increases caloric efficiency to boot. If you want it to be an herbivore just have it eat fruits and grains, it will be able to sustain itself no problem, although even then there is only a few exclusive herbivores on earth, most herbivores are also opportunistic carnivores. ]
[Question] [ In cyberpunk genre, we often see commercial companies (Big Scary Corporations) engaged in military conflict against each other. This can be seen in videogame "Syndicate" and other media, for example. But would it actually make sense in real life? What needs to happen in order for this to begin? What kind of companies are needed for this to happen? What benefits are there for even starting this sort of thing? The only thing obvious for me here is that companies need to have more power over order and law, than the government. By "military conflict" i mean companies openly attacking their competitors factories and offices, assassinating valuable employees, destroying prototypes, deploying spies, etc. [Answer] Yep, we have a history of just that: [The American Mafia during Prohibiton](https://en.wikipedia.org/wiki/American_Mafia#Prohibition_era) To have corporations engage in military conflict, you need: 1. Powerful market interest in the corporations goods (alcohol, soylent green) 2. Competition between corporations to provide the same goods. 3. No less expensive (in time and money) method to handle dispute resolution. The reason Apple doesn't storm Samsung's offices with tommy guns and silly speech impediments is because they have a (dis)functional court system and patent system to resolve disputes. The lawyers hash it out, sometimes spectacularly, and in the end somebody will get what they want and somebody will lose it. Gangsters during Prohibition didn't have any such system. Sure, they eventually built "The Commission" and set up their own form of governance, where disputes could be resolved, preferably without violence. You can see it today with drug cartels. They can't sit down and mediate disputes over territory, distribution rights, land ownership, because their enterprise exists outside the legal system. In your cyberpunk society, the Corporations don't need to necessarily have more power than the government... they just need to have no other means of dispute resolution. If the Government always sides with the side that gives them the most money, or if the courts are so busy that no business cases are ever decided, then I can see a dystopian corporation deciding that they should spend the millions of dollars they currently pump into the legal and bribery department into a private militia. Get things done quick, and probably cheaper. [Answer] # Monopoly on Violence The key point here is 'monopoly on violence.' In the modern world, governments have a monopoly on violence. There are plenty of places where that is not true (South Sudan, Somalia, Syria, Libya, etc), but in general those places have either never had any sort of working modern economy (Somalia, South Sudan) or their modern economy has been completely wrecked by an all-out civil war (Syria, Libya). What you want is a place where the government does not have a monopoly on violence, but there isn't an all-out civil war. The most obvious comparison in the Middle Ages. There was no government monopoly on violence and many minor lords entertains squabbles and feuds that broke out into low grade warfare. They were enabled to do this by their fortifications, which made it too costly for a king with a superior army to defeat them (after all, sieges cost a lot of money). Another apt comparison was the 'Wild West' and its equivalent in the Russian expansion through Siberia. In those places, people just came and went as they pleased and distance made establishing state control difficult. In order to control violence on a local level, people had to band together in 'corporations' (of cattlemen, brigands, sherrif's posses, etc) to deter violence. Two 'corporations' meeting in that context was basically the showdown at the OK Corral. So to get a similar scenario, you have to have a world where there is limited government oversight and difficulty in enforcing claims of violence monopoly on the corporations either due to a. the corporation's ability to withstand a siege from government forces or b. the distance from government control. If either criteria is met, then you can expect corporations to act just like feudal barons and Western gangs. [Answer] Today governments are contracting private security firms to guard assets and conduct paramilitary operations. The privatization of war is big business. The US in particular relies heavily on private military companies. Firms like Blackwater in Iraq and G4S with the Dakota pipeline come to mind. So we already see private contractors engaging in military operations and government reliance on such to an increasingly pervasive degree: <http://www.strategic-culture.org/news/2016/08/19/private-military-contractors-fighting-us-wars.html> All it takes is for two governments on either sides of a conflict that rely on private contractors for this scenario to occur. If governments collapse due to some economic crises or environmental catastrophe one can imagine a dystopia where only corporations and private security contractors survive. In the absence of government, corporations would turn to private security firms to protect their assets and secure resources. People might turn to them to protect them as the only available option. In such an eventuality, those corporations might clash over resources and assets just as governments do today. For further reading: <http://www.globalresearch.ca/the-privatization-of-war-mercenaries-private-military-and-security-companies-pmsc/21826> [Answer] You need a weak state that can't enforce rule of law and strong organizations that failed to assemble a cartel to manage their disputes. Just look to the life of Pablo Escobar and the Gentlemen of the Cartel of Cali to see how your corporations would deal with each other and to the life of El Chapo and Miguel Angelo to learn how one can win these disputes and create a funcioning system. ]
[Question] [ I want to have alternate history where Napoleon fights Ottomans backed by the British. I need British as enemies no alliance with them whatsoever. How to make Napoleon invade Ottoman empire instead of Russia? [Answer] Russia and Britain were at war between 1807 and 1812, but it only amounted to some naval skirmishes. Instead, have the Czar fight a more pointed battle, perhaps with interests in seizing and "liberating" Danish colonies once Britain takes Danish holdings to support its smuggling efforts. The major problem was the the two Emperors didn't agree on a few things that eventually made things very tense. Perhaps, they could agree that France would get Africa and the British Isles, and Russia would get Asia and any Danish holdings, as part of their alliance. Once the US joins the war, Britain will be sorely pressed to keep fighting both nations in earnest, and may lose some of its worldly possessions and colonies. If you eventually want France and Russia to fight, have them fight over the Ottoman lands, which partially are in Europe and partially in Asia (and since in Real Life they argued over Poland, it has some similarities). Without Britain in the fight, the battle between France and Russia could be extremely bloody and not decided quickly. [Answer] Make Russia not breaking [trade blockade of Great Britain](https://en.wikipedia.org/wiki/Continental_System) and make whole blockade much more efficent. Then Napoleon could try to attack Ottoman Empire to get Egypt and, as he tried before, cut British from the India. [Answer] He wanted to do that. The point of the [expedition in Egypt](https://en.wikipedia.org/wiki/French_campaign_in_Egypt_and_Syria) was to set up a French empire in the near and middle east, from the Mediterranean to India. The British took exception, and helped the Ottomans [defend Acre](https://en.wikipedia.org/wiki/Siege_of_Acre_(1799)). Napoleon then abandoned the dream of becoming a second Alexander and turned towards European conquests. The main difficulty of your hypothesis is how to make the Kingdom of Great Britain a friend of revolutionary France instead of its bitter foe. With Britain on its side (or even neutral), revolutionary and then Napoleonic France would have had much higher chances of success; but I don't see why Britain would have abandoned its grand strategy of maintaining an equilibrium of power in favor of making France great. ]
[Question] [ In an alternative universe I'm wanting Nazi Germany to maintain as much of its war-achieved empire as possible, via reaching a peace agreement (and *not* more successful efforts on the war front, or other explanation). Since for most of the early war Nazi Germany had the decisive advantage on the Western front, it theoretically held the advantage in a peace agreement during that time, and even earlier the not-yet-formed allies were extremely hesitant towards becoming involved in the war. What's the latest point before being pushed back that Nazi Germany could have realistically forged a peace treaty/ceasefire with the Allies, and what political shift in Nazi Germany could justify this attempt at ending the war? I'm fine with Operation Barbarossa (or any alternative) never happening if necessary, but beyond that I'd prefer avoiding rewriting history as much as possible to justify the ceasefire. [Answer] # May 9, 1940. Give or take. Though I'm no expert, I'd put the date somewhere in the early summer of 1940 - shortly before the start of the [**Battle of Britain**](https://en.wikipedia.org/wiki/Battle_of_Britain). Late 1939 and early 1940 witnessed a juggernaut the likes of which had not been seen in Europe for a long time. Germany swept through Poland, the Low Countries, and France, while the Soviet Union made gains in eastern Europe and Scandinavia and Japan continued to fight China and begin to take control of Southeast Asia. It wasn't exactly a walk in the park for the Nazis, especially given opposition from Britain and France *before* Hitler set his sights on them, but it was easy nonetheless. Let's step back a bit to my main protagonist, Great Britain. By May 10, Prime Minister [Neville Chamberlain](https://en.wikipedia.org/wiki/Neville_Chamberlain) - famously known for his appeasement of Germany via the Munich Agreement two years prior - has left office, stepping down to let a stronger government lead. While he opposed Hitler after the invasion of Poland and even refused offers of peace, he was not likely to meet the success that [Winston Churchill](https://en.wikipedia.org/wiki/Winston_Churchill) found when he stepped into his first term as prime minister that spring. Given the situation at the time - France about to fall, Europe overwhelmed from the south, east and center, and no significant help forthcoming from the United States - you could say that there was a perfect storm happening. The right things happened at the right time to galvanize British patriotism: * **May 13:** Churchill's ["Blood, toil, tears, and sweat" speech](https://en.wikipedia.org/wiki/Blood,_toil,_tears,_and_sweat) was essentially an ultimatum to Hitler that Britain would not surrender, although that was more explicitly captured on June 4 in his ["We shall fight on the beaches" address](https://en.wikipedia.org/wiki/We_shall_fight_on_the_beaches). * **May 26 - June 4:** The [Miracle of Dunkirk](https://en.wikipedia.org/wiki/Dunkirk_evacuation) marks the end of the British campaign in France as hundreds of thousands of soldiers retreat across the Channel, but it is an early moral victory for the British. * **June 10:** Italy declares war on Great Britain and France. With multiple governments in exile still in London (including Poland and Norway), it becomes clear that Britain is almost alone. France surrenders to Germany on June 25, making this final. Then the Battle of Britain began, around July 10 - the [Battle of France](https://en.wikipedia.org/wiki/Battle_of_France) was over - and Great Britain essentially committed itself to defending what was left of Allied Europe. Only by breaking Britain could Hitler win at this point, and that would require a military victory which you have ruled out. Once in motion, the British military complex would not stop until [Operation Sea Lion](https://en.wikipedia.org/wiki/Operation_Sea_Lion) - the plan to invade Britain - was stopped, and then some. --- It would indeed be hard to justify *why* Hitler would be willing to make this offer. It's true that he offered a peace treaty to Britain and France early in October (both declined, obviously), which is a bit puzzling, given his success in Poland. I wonder of the same rationale could apply here. # Reason for a treaty: * It saves German military power for future battles (Hi there, Stalin!). The German military had certainly suffered losses during the Battle of France - ongoing, as of May 9 - and winning that and then taking Britain was by no means a sure feat. We know, of course, that this failed. * It definitively puts Germany at the top. At this point, Italy has not declared war on Britain of France; Germany is the main Axis aggressor (the Soviet Union is still in the picture). It makes sense to get the whole pie now, rather than have to share it if the Italians get there, too. # Reasons against a treaty: * Defeating France and Britain by force means they really aren't coming back, nor are the governments in exile hiding there. Europe is all Hitler's. * Taking over that much of a continent by force sends quite the message. Other nations (*cough cough* United States *cough cough*) may not want in on this fight. * Hitler didn't have much to make him think that it wouldn't be possible to beat his opponents - again, though pure force. The blitzkrieg had worked so far. Why should it stop? [Answer] **After 10 May 1940 but before September 27, 1940** After looking a bit into this I realized that there were two major problems with this hope: America and Russia. If you want Nazi Germany to survive, we need to keep them out of the war. Let's start with America, although the war began with Nazi Germany's attack on Poland in September 1939, the United States did not enter the war until after the Japanese bombed the American fleet in Pearl Harbor, Hawaii, on December 7, 1941. So we need to keep Japan out of the war to, which means this peace deal needs to happen before japan allied with Germany(they may still do pearl harbor, but they cannot be part of the axis), which is on September 27, 1940. For this, I suggest a timeline where Germany has put in clear unfair small print for Japan in the Tripartite Pact, and thus Japan does not sign, instead being its own side. Now for Russia, this is the biggest problem, as Russia joined in as it was allied with Poland. But this is where your answer lies. Germany needs to sign its peace treaty with Russia somewhere in late 1939 and unoccupy Poland, focusing on its Western neighbors. After that it will still, if nor more, heavily occupy France and likely win in holding it. After 10 May 1940 but before September 27, 1940 is your best bet [Answer] Obligatory "Not an actual historian, just basing an answer off of what I know"... I would say the middle to end of May, 1941. England has pushed back (the brunt of) the German attacks on Britain (the Blitz has ended, but raids are still happening at a reduced rate), but things aren't going well in the rest of the world. England is making some headway in Africa, but they also have to fight a new Nazi-sympathetic regime in Iraq - [Fuhrer Directive No. 30](https://en.wikipedia.org/wiki/F%C3%BChrer_Directive_No._30) said that "The Arab Freedom Movement in the Middle East" was Germany's "natural ally against England", so there were an awful lot of possible insurrections and rebellions that needed to be dealt with. In addition, it was in May 1941 that England began to evacuate and eventually lost Crete, meaning that Germany had cemented its hold over the Mediterranean - at the end of April, Greece had surrendered to Germany, so there really wasn't any opposition left. Inside Germany, May saw the [Strike of the 100,000](https://en.wikipedia.org/wiki/Strike_of_the_100,000). Somewhere around 70,000 workers in Belgium and Flanders went on strike, partly for increased wages, partly to protest the German occupation. The Nazi party was concerned that something like that could happen again, and would arrest 400 people in September 1942 for supposedly planning another strike. They obviously understood that people didn't exactly like living in an occupation, so it would be easy enough to imagine an alternate history where Germany offered peace so that they could stabilize their new population. The other big thing is that in late May, a German U-boat sunk the US merchantman *SS Robin Moor*. While it didn't have as much of an effect on the US population as the sinking of the *Lusitania* did in WWI, it certainly solidified the Roosevelt Administration's dislike of Germany. Shortly after the sinking, German assets in the US were frozen and the State Department asked Germany and Italy to remove all consulates from US soil except the main embassies. While the US was already sending aid to England and China due to the Lend-Lease Bill, the sinking of *Robin Moor* made them dislike Germany even more. If we look at it all through a certain lens, we can see England fighting on its own (plus some aid from the US) against a Germany that is gaining ground all across Europe and getting new allies in Middle Eastern rebels it supports, but facing internal strife from all the land it's occupying. The USSR is still allied with Germany until June 22 (Barbarossa). I can see a German offer of peace being successful at that point, since the US is still unwilling to truly join the war and England has just been hit with a string of defeats. [Answer] You need to remove unconditional surrender from the conduct of the Second World War. > > After the United States entered World War II, Franklin D. Roosevelt declared at Casablanca conference to the other Allies and the press that unconditional surrender was the objective of the war against the Axis Powers of Germany, Italy, and Japan. Prior to this declaration, the individual regimes of the Axis Powers could have negotiated an armistice similar to that at the end of World War I and then a conditional surrender when they perceived that the war was lost. > > > Source: Wikipedia entry on [Total War](https://en.wikipedia.org/wiki/Total_war) Had Hitler sued for peace prior to the American entry into the War, then yes it might have been possible. There is still the small problem of Winston Churchill who would have been most likely to disagree. So this suggests an even smaller window of opportunity. Nazi Germany negotiated a peace settlement prior to Churchill assuming the premiership of Great Britain. Essentially it was the doctrine of unconditional surrender that would have blocked any peace treaty to preserve a Nazi German Empire. [Answer] ### How about May 1941 before Germany decided to invade USSR? Map courtesy of Wikimedia Commons: [![World Map April 1941](https://i.stack.imgur.com/nJRpW.png)](https://i.stack.imgur.com/nJRpW.png) The map is from April, but May is a good month between major events which should give the various groups a chance to cool off. USSR still had its non aggression pact in place with Germany so USSR would not likely get involved. United States had not been involved yet in the war and so would not get a say at the bargaining table. France would still demand its freedom, but Germany might be able to keep part of it. Several smaller countries joined the Axis powers rather than being conquered by them and they would want their freedom too. Italy would likely want to keep a good hold on Africa and possibly Greece. All of these things would eat away at the territory under Germany's control leaving its holdings post peace treaty not being as impressive. If you go any further into the future Hitler and Japan do a very good job with getting countries mad with the Axis powers (USSR and US), which would make trying to settle for peace near impossible. Lastly, note that Japan likely would not recognize a peace deal and would continue fighting. ]
[Question] [ What would the orbit of a planet orbiting two stars look like? Would the planet orbit the stars simultaneously or one after the other? How strong might be the gravity well of such a system be? Any diagrams or pictures will be appreciated [Answer] There are three ways a planet can be positioned in a binary-star system: * The two stars are close together and the planet orbits both of them (technically it orbits their center of gravity). This is called a P-type orbit. Because the stars have to be far-enough apart to not collapse in on each other, this can make for a large orbit. * The two stars are farther apart and the planet orbits one of the stars. This is called an S-type orbit. I asked [this question](https://worldbuilding.stackexchange.com/q/25166/28) about the effects of the secondary star on the planet (gravity, etc); see the math there for details, but yes it can be stable if the stars are far-enough apart and the planet orbits its star closely enough. (I was asking about the habitable zone.) * The planet orbits the stars in a figure-8 pattern. This is theoretically possible but unlikely, as explained [on Physics.SE](https://physics.stackexchange.com/a/67260). [Binary stars: friends or foes?](https://planetplanet.net/2013/06/06/binary-stars-friends-or-foes/) by Sean Raymond, which Sean linked to in [this explanation of orbit types and habitable zones](https://worldbuilding.stackexchange.com/a/48599/28), contains more information, including these helpful diagrams: [![orbit types](https://i.stack.imgur.com/KBIDs.jpg)](https://i.stack.imgur.com/KBIDs.jpg) [![orbital separation and habitable zones](https://i.stack.imgur.com/yqtFl.png)](https://i.stack.imgur.com/yqtFl.png) See also [the Wikipedia article on binary stars](https://en.wikipedia.org/wiki/Binary_star). [Answer] For a consideration of simple cases, see ["Theoretical Orbits of Planets in Binary Star Systems"](https://www.academia.edu/3029649/Theoretical_Orbits_of_Planets_in_Binary_Star_Systems) by S.Edgeworth on [Academia.edu](https://www.academia.edu); it has pictures. In general, gravitationally bound systems containing three or more bodies are mathematically chaotic; our solar system appears to be not chaotic (on the not-too-long term) only because the Sun is so much more massive than the rest of the system. In a multiple star system the orbits of planets may be very complicated -- see [*The Three-Body Problem*](https://en.wikipedia.org/wiki/The_Three-Body_Problem) by Liu Cixin for a masterful fictional treatment. [Answer] I agree with the answers of AlexP and evilscary, but want to add that we are likely to see some chaos in the orbit like we do with the small moons of Pluto. I want to recommend, that you study this system as a possible example. I consider the small moons of Pluto to be a good example for another possible orbit of the two sun system because: 1. Charon and Pluto do orbit around a common barycenter, which lays outside of both. The other moons (Styx, Nix, Kerberos and Hydra) are way smaller (which means less gravity) and can bee seen as orbiting the barycenter of pluto and charon. 2. There are some resources about it (see [1], [2] and [3] as a start). [1] M. Showalter and D. Hamilton, “Resonant interactions and chaotic rotation of pluto’s small moons,” Nature, vol. 522, no. 7554, pp. 45–49, 2015. [2] <https://en.wikipedia.org/wiki/Moons_of_Pluto> [3] S. Stern, F. Bagenal, K. Ennico, G. Gladstone, W. Grundy, W. McKinnon, J. Moore, C. Olkin, J. Spencer, H. Weaver et al., “The pluto system: Initial results from its exploration by new horizons,” Science, vol. 350, no. 6258, p. aad1815, 2015. [Answer] There are two possible orbits here: The first is a figure 8 orbit, in which the planet orbits star A first, then switches to star B at the point at which the gravity fields meet, then back to planet A again. I imagine the gravity experienced by this planet would be intense; tidal forces would slowly tear it apart and as such it would probably only last a few thousand years before becoming gravel. The second is where the planet orbits a small star which in turn orbits a larger star. Gravity in this orbit would probably be a lot more tolerable, even comparable to most 'normal' orbits. ]
[Question] [ Is there any solid, scientific counterargument against the hypothetical explanation that attributes dark matter as matter in hidden planes of existence? I am trying to construct a world in which there are creatures and objects similar to ordinary objects (physically, if not biologically), and they are normally hidden in different spatial planes where only gravity can pass through, thus appearing like dark matter. The kind of "matter" in the hidden dimension would resemble monsters and spacecrafts of a fashion not too deviant from human imagination, they also supposedly inhabit planet-like bodies, although that would not be required. I wonder if there is any counterarguments in physics that will undermine this construction, for example, could one refute this claim by pointing out the fact that an amount of matter packed as densely as dark matter appear to be packed would surely form black-holes or other intelligible structures like stars and planet which should cause gravitational lensing effect that is different from what is observed. [Answer] This has been proposed, believe it or not. Gravity is the weakest of the four fundamental forces, a mystery which has been dubbed the [hierarchy problem](https://en.wikipedia.org/wiki/Hierarchy_problem). Several solutions have been floating around; one is that there are [large extra dimensions](https://en.wikipedia.org/wiki/Large_extra_dimension) through which gravity propagates. Gravity behaves according to the inverse square law in three dimensions (in the Newtonian approximation from a point source), and as $$F\propto\frac{1}{r^{n-1}}$$ in $n$ dimensions, so as $n$ grows, the force should get weaker. If gravity is the *only* force that can travel between dimensions, this solves the hierarchy problem. This is a case of [brane cosmology](https://en.wikipedia.org/wiki/Brane_cosmology), where the universe is represented as a surface embedded in higher-dimensional space, possible adjacent to other universes. It can also be taken a step further to imply that matter from these other dimensions should interact with matter in "our" dimensions through gravity, mimicking dark matter. This fits in well with non-baryonic dark matter theories, as dark matter doesn't interact with normal matter through the electromagnetic force. Brane cosmology implies that the other three fundamental forces are "confined" to the surface of the branes. This solves the hierarchy problem by assuming that gravity "leaks", for lack of a better word, through these extra dimensions. Fun anecdote: Models of astronomical observations over a decade ago by [Qin et al. (2005)](https://arxiv.org/abs/astro-ph/0508572) were interpreted by the authors as being [evidence of three extra dimensions](http://www.nature.com/news/2005/050829/full/news050829-18.html). Dark matter particles wouldn't directly travel through them, but would *interact* through the extra dimensions. The scientific community is very much not convinced. The observations still require dark matter to exist, but simply to be something that can self-interact in these extra pathways, so not quite what you're looking for, but similar. This should not be confused with the idea of compactified extra dimensions (think tiny, rolled-up dimensions), which have also been proposed to explain dark matter. This would lead to these strange things called *Kaluza-Klein states*, which could be dark matter particles (see e.g. [Cornell et al. (2014)](https://arxiv.org/abs/1401.7050), although I haven't read the paper - it's largely beyond me!). [Answer] The solid scientific counter-argument has to do with your definition of hidden. The observed behavior of dark matter is that it does not or very weakly interacts with electromagnetic radiation, yet it exerts a graviational force on the rest of the universe. What mechanism do you then propose to hide normal matter so that it can interact with non-hidden universe with the force of gravity, but not the electromagnetic force?' If the answer is magic, then thats fine. But barring magic, the only thing I can think of that fits that description is actual black holes. So if by 'hidden' you mean, hidden in black holes, I suppose that is best we could do. There are various theories that is much of dark matter is [primordial black holes](http://www.nasa.gov/feature/goddard/2016/nasa-scientist-suggests-possible-link-between-primordial-black-holes-and-dark-matter). But then, any 'normal matter' of monsters or spaceships inside a black hole won't be coming out any time soon. Alternately we could suppose that there were some way a different force other than gravity could be strong enough to prevent the electromagnetic force from escaping it. A well of strong force or weak force? I don't even know how that would work, so I won't spectulate, but you are still left with the dilemma of how EM radiation cannot escape from the well of this other force yet gravity can. All of this is pretty speculative. Keep in mind that dark matter and dark energy shouldn't be viewed as things that will actually 'exist' in future science. The concepts are nebulous and nobody really has any idea what they are; which means they sound just like luminiferous aether and the like. Consider that modern cosmology considers dark matter and dark energy to be 27 and 68% of the universe, respectively (according to [Wikipedia](https://en.wikipedia.org/wiki/Dark_matter) and [this paper](http://www.aanda.org/articles/aa/pdf/2014/11/aa21529-13.pdf)). It seems unlikely to me that when we finally figure out what those things are, that they are a. just one thing and b. will be referred to as simply 'dark matter' and 'dark energy'. So, after many detours, my final answer is: if dark matter is really just normal matter hidden in a place where EM radiation cannot escape, I don't see how the 'dark matter' can escape either. [Answer] Let's just assume that "hidden" can be tuned as necessary, just for the sake of argument. Dark matter is observed to *not* behave like regular matter. Regular matter (the stuff we're made of) condenses down to stars and galaxies. To do that, it interacts with itself: Gas and dust scatter of other gas and dust, eventually randomizing ("thermalizing") their motion to allow that condensation. When we observe dark matter gravitationally, we find that it doesn't do that. It's in "halos" much larger than the normal-matter galaxies they contain. That means dark matter interacts *much* more slowly/rarely than regular matter. From this, and some calculations, it appears that there are very likely no "Dark Stars" (obligatory shout-out to the [incredible movie of that name](https://www.imdb.com/title/tt0069945/)) in nature. Without the ability to interact like regular matter, dark chemistry, dark biology, dark engineering would be *very* different. There are not likely to be any dark matter spaceships we'd recognize. ]
[Question] [ In my world there is a neolithic civilization of people who inhabit earthen trenches. The people first soften the earth with ... fluids ... and dig out 6 - 12 foot deep trench systems that extend out for many square miles with bamboo and ceramic trowels & spades. Though digging out massive trench systems with what is essentially a grass stick is extremely labour intensive, they can provide all that they need in and around the trenches; planted oak trees to make acorn bread, planted potatoes, yams, snails and mushrooms for extra food sources, bamboo, hemp and stone for building material, rope, cloth, you get the point. Also, since the trenches are easily defendable , they need not worry about invasions. However, there is one issue which they cannot overcome: ***The Rain*** When it rains any significant amount the entire trench system is partially flooded. Crops get drowned and buried, food is spoiled, paper and clay tablets get ruined and lost in the sludge, fungus grows on stored seeds and earth is turned into mud, which makes the trench practically unlivable until the trenches completely dry, which may take days. That, however, isn't even the worse part. Any sort of flooding necessitates a complete evacuation. Everything a trench dweller may own is completely lost under the murky water, sometimes including their life (since they can't swim) and it basically turns their homes into a permanent canal, forcing them to start all over. On Top of all of that the problem follows them wherever they go, since they have to live near some sort of water source. My Question is: how might such a civilization keep water out of their trenches? [Answer] With the massive amount of manpower they put into digging these trenches, they would certainly learn how to dig them correctly. Basic civil engineering would suggest that the entire network be dug in areas where water can flow out of the trenches. It'd be the inverse of what we do for irrigation channels. Instead of one source of water flowing into many channels, the trenches would need to be designed with a slope such that the water all flows into trenches dedicated to moving the water elsewhere. Such a civilization would never build at the lowest point of a basin, so that they could always drain their trenches. [Answer] They would slope the trenches so that they would naturally drain to a sump. They would also build [French Drains](https://en.wikipedia.org/wiki/French_drain) as part of their trench systems - layers of gravel or other quick-draining porous materials at the bottom of the trenches, and near the surface on the upslope side of trenches that run parallel to the landscape's contour. Even something as simple as a layer of wood planking 20-40 cm above the bottom of the trench would work. [Answer] Ancient civilizations that did massive earthworks were often quite good at large scale earth shaping. In some cases, they flattened the tops of hills and made very level pads similar to what we can do with a bulldozer today. If a civilization lives in trenches, it is very likely that they would be not only expert diggers, but very good at laying out long straight runs and figuring out slopes. I would think that each trench would probably have a sub-trench/gully either down the center or along one wall, and that the ENTIRE trench complex would be cut at a slight angle, creating a slope. Long trenches would follow the slope, shorter trenches would never quite be perpendicular, allowing good flow of water down to the lowest corner. Optimally, the entire thing would be built where there was lower ground nearby (or perhaps take up the top of a large, flattish hill). The lowest corner of the trench complex would have a channel cut to the lower terrain. If you look at ancient sites like Petra, you see that ancient peoples had some pretty impressive hydro-engineering skills. Obviously in the case of Petra, they were collecting water in a dry environment, but they still cut a network of trenches and cisterns that collected rainwater from a wide area and stored it for them. Which just gave me a second idea: instead of dumping excess water, they might make a BIG cistern lined with clay or whatever and store the water for later use. There are ways this could be done that would not lead to a contaminated pool of stinky badness but rather a cool "tank" full of drinkable water year round. [Answer] Use bamboo piping into a lower reservoir (hydrodynamics) will keep water flowing out and where ever you want them to go, you could use it to produce a clean water source internally even by them throwing, I think Coal, and some sort of fiber to filter the water out which makes yourself even more defensible... You can also use this as a built in simple plumbing, which can then be used for fertilizer too... [Answer] Building a rampart on each side of the trench would help further, and be the natural place to deposit the cutting material. Also, the trenches would be deeper as a consequence. [Answer] The Trenches will have small trenches next to the "downhill" wall. Slabs of stone or wood can be used to mostly cover it, leaving openings for drainage. Small trenches are created out of and on the uphill side of Trenches to divert as much run off from entering the Trenches in the first place. Wide canopy trees are planted on the rims of the Trenches to create a natural roof to cut down on the direct precipitation. ]
[Question] [ If dolphins came out of the water again and evolved into something approaching human intelligence, how would that look, taking into account their physical characteristics and what happened evolutionarily when they moved into the water? They would have to be able to walk again, so how would this work? [Answer] Well, some might argue that dolphins already have something approaching human intelligence... We can take it that the three necessary factors for a species to develop technology are: * Intelligence - to conceptualise what technology they want to develop * Language - to communicate complex instructions and ideas with other individuals * Manipulation - to be able to use tools and materials to realise their ideas You can think of these as a virtuous cycle, if you have all three they reinforce each other and eventually you end up with a technological society like we have today. Dolphins arguably have the first two, but they lack the ability to manipulate their environment: they can think about building tools, they might even be able to discuss building tools, but they'll never be able to actually build them because instead of arms and hands they have useless fingerless flippers. So back to your question, we can assume that dolphins, being perfectly adapted for marine life, are probably not going to leave the sea willingly. So let's assume a push factor: something is gradually making the oceans uninhabitable and the only course for survival to adapt to the land. There are several significant obstacles for dolphins surviving on land. Beached dolphins tend to die relatively quickly of either thirst, overheating, or asphyxiation. The first is due to the fact dolphins don't actually drink; in the sea they gain all their hydration from the fish they eat, a dolphin that doesn't eat will die of thirst long before it dies of hunger. Overheating and asphyxiation occur because of the sheer weight of the dolphin's body fat, which, while essential for maintaining warmth, buoyancy and internal pressure while the dolphin is in the water, will quickly kill a dolphin outside of the water by trapping in too much body heat or just weighing down the pumping of its lungs. So, to survive out of the water, a dolphin is going to have to become a lot more like a seal. It will have to stick to very cold environments, it will have to reduce its internal body fat content, and get used to eating less frequently. While on land it will probably move like a seal does: by somewhat gracelessly bouncing around on its belly. Walking is probably out of the picture. As you can see from the below, a dolphin's hind legs are completely atrophied, and only a tiny vestigial pelvis remains. Once evolution atrophies a feature to this extent, it is very unlikely for it to return. [![Dolphin skeleton](https://i.stack.imgur.com/8OcQa.jpg)](https://i.stack.imgur.com/8OcQa.jpg) The unhappy conclusion though is that intelligence is expensive. It requires a lot of resources diverted from elsewhere and a constant supply of high protein food to fuel the large brain. In lean times, and when facing having to adapt to a new environment, the massive brain is probably going to be the first thing the dolphin will sacrifice. If the same thing that makes the sea inhospitable for the dolphins also makes it inhospitable for the fish however, then the dolphin will also have to eventually adapt away from the semi-aquatic seal lifestyle too, into something completely terrestrial. Below is my idea for what the 'final product' would be: [![Land dolphin](https://i.stack.imgur.com/vU9F8.png)](https://i.stack.imgur.com/vU9F8.png) This is an animal with a much smaller brain than present-day dolphins, and a greatly truncated body size (probably about waist-high against a human). It has an ill-adapted sense of hearing and smell, so it hunts mainly by sight, and mainly for prey like small rodents. The hind-legs are still gone, so its flippers have adapted back into legs, allowing it to walk somewhat like a flightless bird. Dolphins are born with some vestigial fur, so I've been kind and allowed it to regain a full pelt. [Answer] **The big question is this: Will it become human like, then come out of the water, or will it come out of the water, then become more human like?** For a dolphin to come out of the water, it will have to sacrifice a lot of what already makes it human like as Tom O'Daighre's answer already attests to. Coming straight onto land is only an evolutionary pressure for the dolphin as is, if the sea has become very inhospitable at which point a lot of a dolphin's intelligence will likely be sacrificed first. Instead consider that dolphins first become better tool users. While they already have basic tool use skills like using sponges to sift sand for prey without hurting thier noses, some possible tools are too hard to want to manipulate with thier teeth. It could start as a simple as discovering they can use their flippers to stack rocks making houses where they can safely hide from sharks or other predators. Granted, dolphins are already normally apex or near apex predators in most areas that they live, but a population boom in killer whales, or one of the larger shark species could force them onto the defense. Or perhaps they are making traps, or take up farming, or are creating new micro ecosystems for themselves the way you see them form around oil rigs and other man-made structures. It, does not matter why they are stacking rocks as long as they convey some advantage. As the generations go on, the dolphins who have longer more dexterous flippers can make better structures more quickly improving their odds of survival. Eventually some lucky dolphin will be born with stubby little fingers, this is a huge advantage because now they can hold smaller rocks or even sticks adding all sorts of construction options for these builder dolphins, like being able to make a door to keep out predator who could otherwise follow them into their homes or something to snap shut trapping prey. Now this is where going back to land becomes a thing. Fresh water has a lot more rocks and sticks to work with; so, dolphins who go inland into gulfs, rivers, and lakes will have a lot more resources to work with. Once their fins become more arms like they can even start figuring out spears and tool crafting which will make them the undisputed apex predator of the world's bodies of fresh water. Living in warmer fresh water, they now don't need all that blubber; so, those who are lighter can start to drag themselves up on to land to take advantage of all the edible plants and wildlife that likes to live near the water. So now you have something that is more or less a freshwater mermaid. Now, their tails will continue to prefer water for a while, but land now offers something they will never get in the water, and that is fire. Being able to cook will open up a whole plethora of new food sources for them and help them fight food born illnesses; so, this will lead to features that prefer the ground to their rivers. Re-evolving legs is a long path to go for the dolphin; so, they may more likely go with slithering like a snake. In the end your dolphins would end up looking more or less like this: [![enter image description here](https://i.stack.imgur.com/7Wd38.png)](https://i.stack.imgur.com/7Wd38.png) [Answer] Well, as you already know, dolphins have already lived on land before. They're descendants of terrestrial mammals. Going back? They've the lungs and the unique construction of their flippers (former forelimbs) to work with. That's a plus. Their lungs presumably keep them in shallower waters, so they're already that close to land. Not to mention the fact that they already breathe air. Their flippers seem to have the complexity that our ancient aquatic ancestors had before making the jump, so that's another plus. And they probably have some vestigial remains of former hind limbs. All in all I'd say that's a fair start. I think the simplest way to approach this question is as if you were reversing the process of their evolution a bit. By means of absurd chance and natural selection they somehow become tetrapods again. They take up life on land and ever so slowly continue to adapt. Eventually they'd find themselves in a survival-based scenario that promotes the evolution of walking on their hind limbs. Probably gathering food faster than the competition or something along those lines. As for what exactly that would leave them looking like... I don't want to sound dismissive, but a lot of that will be up to you. It's just the nature of evolution. It's all circumstance. Even with my limited knowledge of biology, I think it's fair to say that it's impossible for anyone to be sure. But that can be a good thing. Plenty of room to be creative. Play around with the jaw, the dorsal fin, the positioning of their eyes. Do they continue to give live birth? Does their skin remain rubbery, soften, or become something we've never seen before? Maybe emphasize the characteristics they have now. I'd look for some artists' depictions of dolphins' ancestors to start. Hope this helps. [Answer] Given the need to walk again, I imagine that they would have to go through a stage akin to that of [mudskippers](https://en.wikipedia.org/wiki/Mudskipper), though with possibly less overall change required to resituate themselves for living on land again. Beyond that, the rest would depend too strongly upon random variables and chaos theory for me to hazard any guesses. [Answer] My answer will incorporate some non-dolphin get them out of the toxicity of the changing water. Since the water is likely becoming toxic due to humans, I will allow a group of humans to help out some dolphins by creating a "landed dolphin refuge". Since dolphins are intelligent, humans chose to help them out in hopes of them one day being evolved enough to function in modern society. They would likely start coming out of water near the poles as Tom O'Daighre suggested in his answer because their fat layers would insulate them heavily, so the first dolphin refuge will be somewhere in Antarctica. since dolphins can't really move on land the humans will have to help them out here. My first thought is that they lay on a skateboard roll around using their fins to push them. Of course a human manufacturer will have to train them at first and then provide the skateboards. I'm not sure what language capabilities dolphins have, but I will assume they currently have a vocabulary much less than humans, and also much lesser sentence structure. Quickly their speech will become somewhat similar to humans (likely still as patterns of clicks and whistles); language is learned by humans, so I think this will evolve as quickly as dolphins can invent new words and structures. There will likely also be a human effort to learn dolphin language, and communicate with them, further boosting their linguistic abilities. Within 3 or 4 generations I would expect them to communicate on a level similar to humans. their language transmission and recieving capability over air will likely also improve. Humans could introduce more advanced evolutionary tactics such as selective breeding or eugenics, to develop better on land characteristics. I will also prohibit direct gene manipulation for ethical and possibly technological reasons. over 25 or 30 generations of dolphin-imposed selective breeding, their fins would begin to lengthen into arms, allowing them to scoot better on land while still swimming, and catch things with their arms, likely an early development will be throwing/kicking dirt (or snow, as it is Antarctica) at prey. In a few more generations they may also begin to re-develop fingers to use tools like spears or axes to hunt or fell trees, dig holes and develop primitive structures. Likely they will be able to hunt on land but decide to continue hunting/fishing underwater. With human level communications skills, I'd be surprised if they did not catch the whole capitalism thing. Drilling companies could employ them to inspect underwater equipment, with time they could possibly repair or perform preventative maintenance underwater. The navy may employ them in submarine detection, and possibly covert insertions. they could also be employed as underwater tour guides, or underwater archaeological specialists (or marine biologists, etc). As amphibious beings dolphins could hold many positions we have not thought of yet. ]
[Question] [ ## Background Information As we all know, life as we know it today is caused by the process of natural selection, sometimes referred to as *survival of the fittest*, as proposed by Darwin. Essentially, the organisms better at surviving would be more likely to pass on their genes. Before Darwinism became widely accepted, Lamarck proposed a similar theory. The following picture describes it perfectly (with the example of a giraffe): [![Lamarck's Theory of Evolution](https://i.stack.imgur.com/wKfuI.jpg)](https://i.stack.imgur.com/wKfuI.jpg) The difference between his and Darwin's theory is that he believed that a traits acquired in the lifetime can be passed on. ## Question Could life as we know it arise if Lamarck's theory was correct rather than Darwin's? [Answer] **No** The giraffe neck is a commonly given example, but there are lots of features of Lamarckian evolution that exclude it from being a possible explanation of the origin of species. "Inheritance of acquired traits". One version of Lamarckian evolution imagines a blacksmith. He uses his arm muscles, which respond by growing larger. His children are then born with naturally larger muscles... However many of my acquired traits are damage. For example I have sun damaged skin, if this trait were passed on, my descendents would have more damaged skin from birth. For Lamarckian evolution to a possible, there would need to be a mechanism for distinguishing "good" acquired traits from harmful ones "Striving". A proposed solution to this is that only traits which are acquired through effort or choice are transmitted down the generations. While it is reasonable to imagine a Giraffe striving to reach leaves, it is not a solution for how sight could evolve (trying to see doesn't improve your sight) nor can it explain evolution in plants or simple animals (a plant doesn't strive to photosynthisise) "Reductionism". The mechanism of Lamarckism would be hopelessly complex. It would require the animal to have a mechanism to analyse its current state, and then rewrite its DNA in order to reproduce. There is evidence that there is non-genomic transmission from mother to child through the womb, this cannot explain the origin of species. [Answer] **So summed up,** evolving is now instead of: "sorting (live/die) of a random variation" consists of the body adjusting to behaviour caused by will, caused by a "need". That may even to some extent be correct, as training your body is essentially to change its form through new behaviour. A problem then arises: "How is this new form transferred to the next generation?" This is at least partly possible through [gene activation](https://en.wikipedia.org/wiki/Regulation_of_gene_expression). That is, what genes are active and affects the shape of the giraffe is not directly possible to read out from the DNA, the "source code". DNA is packed together, and the way is it packed affects how active different genes are. The proteins packing the DNA is of course also coded in it, but exactly what packaging-proteins that are active are affected by... the packaging. Recursively, this means that not all information in the system is recoverable from the base pairs alone. (mutations and actual changes in the DNA is necessary in the long run though. Darwin's theory is a must then, as Lamarck does not cover the concept) But Lamarckian evolution evolution also includes one more component: Intelligence. A giraffe not longer reaching the leaves, knows that it much stretch. In contrast, a bacteria no longer reaching its source of food simply dies. Evolving is then back to Darwin's variations and sorting. One can therefore say that Lamarckian evolution is possible, and even actually present, but only in high-complexity systems. That means, to just pin down the point, Lamarckian evolution can not explain *how* complex organisms originally evolved, leaving it insufficient. [Answer] As always, I love world building questions which try to explore some novel approach to life, only to find that nature has already found a way. It's marvelous what nature can do. Lamarkian evolution actually does happen, to some degree. While much of our genetic evolution is very Darwinian, there are plenty of example of extended phenotypes which get inherited from the mother in utero. Many traits of a child find their origins in mother's choices while pregnant. Your baby's sense of taste, for example, gets partially developed from the mother's diet. Live in a part of the world where eating garlic is essential for life? Your child will actually pick up a taste for garlic from the amniotic fluid it lives in, long before it ever sees the bulbous herb. Perhaps a love of garlic isn't exactly a life skill, but other traits that operate this way are very valuable. For instance, it has been found that a baby reacts to mother's stress hormones in utero. If mommy has found that the only way to cope with the harshness of life is through the stress hormones like cortisol (which tune the body to face the stress), the baby will develop to generate more cortisol in stressful situations and decrease cortisol slower after the stress is removed. This has actually been [measured](http://www.livescience.com/43579-poverty-stress-infant-development.html), correlating maternal cortisol levels during pregnancy to cortisol levels produced during the baby's first blood draw. Sound harsh? Maybe not. One of the known effects of cortisol is a decreased immune system, and worse allergic reactions. These sound useless right? Maybe not. Biochemically, it suppresses outputs of Th1 helper T cells, while activating Th2 cells to encourage them to produce more output. As it turns out, Th1 cells are primarily involved in fighting bacterial and viral infections. Th2 is more involved with our defense against extracellular parasites like worms. Now we don't have many worms in our modern 1st world life, so we don't benefit much from Th2 upregulation. However, if you are living in a part of the world where worms and other parasites are a regular part of life, this response is very useful. So we have an example of Lamarkian evolution, at least at an extended phenotype level. If mother deals with a lot of worms in her life, her cortisol levels will tend to be higher. The child will then develop accordingly, and be born more ready to deal with the infectious world around them than they would have been if mom didn't stress her body. And likewise, if the baby is a girl, it is likely that her stress levels will be passed to the next generation. [Answer] # Yes My answer is short and simple, because this question doesn't really need a long answer. Your question is like asking, if Prometheus really created humanity, could humanity exist? The answer is obviously yes. These theories were designed to explain why the world is the way it is. If it is proven correct, then the world isn't suddenly and irrevocably changed, it just remains the way it is. [Answer] # Only if you have the whole thing As the answers above have stated, half of Lamarckism won't do anything. But, the whole of the theory will work wonderfully Lamarckism contains two different evolutionary forces: An adaptive force, which allows animals to adapt to things over their lifetime, and the thing that everyone seems to leave out: The complexifying force, which is how, under Lamarckism, new organs like the eye evolve ]
[Question] [ Following on from [my previous question](https://worldbuilding.stackexchange.com/questions/30998/what-kind-of-historic-event-would-precipitate-a-worldwide-corporate-dystopia), where we brainstormed the events that might lead up to such a hellish world, I've been thinking over what the social structures and divisions of power might be like here. What are the implications of living in a society where profit-maximising organisations write the laws and print the money? The fundamental principle I want to start from is a world where 'employee' and 'citizen' are synonymous. Corporations don't just hold land, they rule it independently of any oversight. They have their own military forces and intelligence agencies. You don't just work for a corporation – you live in it. The corporation provides your accommodation, your utilities, your food, your entertainment, your news. The corporation pays you (of course, in currency that you can only spend with the same corporation). Perhaps the divisions between corporations are so entrenched that they have different accents or dialects – replacing the languages that exist today across geographical nation-state borders. You don't just leave your job – you defect, becoming a stateless traitor who exists outside the jurisdiction of the (corporation's) law, and no longer has any legal rights. At first I thought it would be interesting if the boundaries on the world map were redrawn, not around nations, but around huge regions corporate control. Big coloured blocks that say things like “Maxicorp” and “Worldnet Telecoms” and “Rainbow PLC”, because that's a compelling mental image and it would be fun to run with the equivalence for a while. But I became less sure about it after going over the implications. If huge mega-corporations who own land on a national level are supposed to provide for all their citizens, they would have to have many subsidiaries that provide those services. Worldnet News, Worldnet Energy, Worldnet Hydroponics (for instance). It would be more interesting if all the subsidiaries had their own brand identities and personalities – and perhaps even if they weren't monopolies, but competed with each other, all under the umbrella of the e.g. Worldnet parent corporation. In my head, this looks kind of like a feudal system, with minor firms fighting and out-competing and spying on each other all under a single mega-corporation that keeps them in line. But this is getting a little strange, and sort of undermines the central conceit a little. Maybe, because of the internet, geographical borders are no longer important, as all corporations operate globally and monopolise different parts of human society (but this limits the potential for competition and delicious industrial espionage plotlines). Or, maybe each corporation-state not only has its own geographical borders, but has *its own internet*, making it easier to control the news from their perspective and maintain public opinion and brand loyalty. Basically, I guess I want to write a story set in a world where the horrors of corporate profit-seeking are combined with the powers that come with being an established government, but I'm unsure whether those horrors should come from corporation-governments as monopolies (which is chilling), ruling entire country-like entities on the map, or from corporation-governments as competitors (which is also chilling, but in a different way), ruling different aspects of society but independently of geographical boders. Are those two themes compatible within the same story set in the same society? Or am I overthinking it? [Answer] As you mentioned in your question, you're basically describing a feudal system of government. This type of crossover between government, economics, and military has existed several times in our world's history, including medieval Europe and feudal Japan. More explicitly, the difference between a middle level manager in your corporate autocracy and a 17th century English baron is spelling. To illustrate: Land is owned by the King of England Incorporated, which is managed by the CEO Charles I. KoE Inc needs someone to manage food production, so Charles hires Jacob Astley to manage several farms and other production facilities at Reading. Jacob gets the fancy new job title "Baron Astley of Reading", which sounds fancy, but really his life is made up of accounting nonsense and dealing with low employee satisfaction. Unfortunately for Charles, some of his managers decided they wanted the Board of Directors to have more say in business decisions. Charles wasn't keen on this, so these managers staged several strikes, protests, and riots which eventually led to open war between departments. At the end of it all, Charles was forced into making concessions to the unionized managers and then publicly assassinated. --- Hopefully, this little historical illustration demonstrates that corporate government is nothing particularly new to the world. Whether you pay 30% of your paycheck to a government in taxes, or 30% of your paycheck is withheld by your employer for benefits and license fees, the practical consequences are more or less the same. But now that we've established that governments *are* corporations, we can look at your question in a very different way. Today, most existing governments lack competition. If you don't like the way Wal-Mart does business, you can shop at Target. But if you don't like the way Congress does business, your only option is to emigrate - a very painful, expensive, and uncertain process. But what if it wasn't so? Suppose it was as easy to move to a different government as it is to shop at a different store? Open borders, more or less, with reduced transportation and housing costs. The stiff competition between governments would drive efficiencies in government, reducing costs and increasing benefits all around. Great for employee satisfaction! But obviously this would mean less profit for the politicians, so open borders is definitely not a profitable option for those in power. And *that*, I believe, is the answer to your question. Corporations competing against each other for labor is bad for profit. It means offering more benefits, higher wages, and better workplace conditions - i.e. higher operating expenses. So closed borders with a captive labor pool is the ideal for maximized corporate profit. How your corporations keep those borders closed - whether through economic incentives, propaganda, or military enforcement - is up to you. I think it'd be a combination of all of them, as it is with government today. [Answer] To answer the title question, you must first decide the nature of your corporations. Do they still specialize? Or does each one partake in literally every every sector of industry? I'll tackle the latter scenario first. ## Scenario A: Corporations participate in every field The mega corporations that have become nations have done so by expanding *horizontally*, until they monopolize all sectors of industry for a geographic region. This scenario results in clearly defined maps, and the mission statement of each company is (ostensibly) to provide the best quality of life for it's employees. I suspect there would be a lot of superficial effort to make the regions *seem* more like nations than companies, i.e. names such as "The United States of Google" or "The Employees' Republic of Samsung". This would be a classic dystopia where wars are referred to as hostile takeovers. ## Scenario B: Corporations specialize in specific fields These are companies that more resemble the ones we have today, but have grown to monopolize their specific field. In this scenario, geographic borders don't make sense, because the companies are still very dependent upon each other. What *would* be plausible is if the companies had been integrated into existing governments and became synonymous with the appropriate branch/cabinet/department of government, e.g. Verizon is now "The Department of Communication" and Walmart becomes "The Cabinet of Consumer Purchasing". In this case, employees are still citizens of the parent nation, but which "department" of government they work for can greatly affect their rights (guaranteed now by union contracts rather than a constitution). Note that this scenario could plausibly evolve into the first. [Answer] Coase's Theorem suggests that corporations will tend to out-source (keep outside the company) any and all services that are cheaper to purchase on a per-transaction basis than to keep in-house. As the example of communist societies shows, large organizations are rather bad at the kind of information gathering required to fully manage an entire society, from land to work, to food, to transportation, to shelter, to entertainment and security. However, imagine a world managed by AI-run corporations. It may be within their grasp to rule with the kind of totalitarian attention to minutia ("all employees must brush their teeth in the morning!") that current bosses can only dream about. It is further conceivable that there would be a concept of market-share. An AI corporation could gradually expand its reach into a new neighborhood, getting individuals to "switch allegiance", up to the point where it has captured so much of the market, it is prohibitively expensive for other corporation to maintain a presence in that market, and they withdraw. Hence, the local monopoly you were mentioning in the OP. [Answer] Yes they would. There's a lot of profit to be made in war and borders is one easy way to get into war. Just think about how many REAL wars were "officially, a war about borders but actually, a war driven by profit". The corporations would segregate us all into tiny pieces. They would enforce different languages and cultures so that we cannot sympathize with each other. They would invent senseless rules about which weapon can be used where in order for them to sell a more wide-range of weapons for all the different legal cases. [Answer] Why would corporations **want** to treat their employees as citizens? A citizen and a state have mutual obligations, allegiance for equal protection under the law, taxes for defense against foreign enemies. Even an employment relationship is too restrictive for some modern corporations. They want subcontractors, or they match "independent" contractors with consumers for a piece of the action -- the contractor pays costs and taxes out of his or her percentage, of course. No corporate healthcare or retirement fund, either. ]
[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/30533/edit). Closed 3 years ago. [Improve this question](/posts/30533/edit) You finally have it. Technology, decades ahead of the rest of the world, that if scaled up will allow you to conquer the entire planet, to finally achieve your dream of bringing peace and mandatory cat ownership to mankind. You have a modest endowment of a few billion USD thanks to the obscenely profitable legitimate cat food business you ran as a cover (you are a genius, after all, just bent on world domination). What you need to do now is set up an initial base of operations. Completing this first step is needed to allow you to set up your (fusion-powered) droid and drone factories. **Where is the best place on Earth to get started and, more importantly, why?** [Answer] Everywhere..and nowhere. Even with the most lethal weapons controlling the world would be quite difficult. Look at the US invasion of Iraq. Compared to the weapons Iraq had the US had an overwhelming weapon superiority, in numbers, quality, and technology. They still ended up leaving Iraq without any real success. Why, because destroying a nations defenses are not the same as controlling the people. To control the people you need effectively boots on the ground, intelligent people right there to control the area your in. A giant super-bomber or orbital death ray is great at blowing up big military weapons, but it does little to keep people from refusing to pay taxes, or rioting, or gurella warfare with simple weapons that are no threat to orbital death rays, but still lead your infantry to be afraid of leaving their barracks. Unless your willing to do a full on terror mode, where you make everyone too terrified of you to do anything else by killing anyone that does anything at all to upset you your find the people resisting your rule vehemently long long after your super-weapons have destroyed all major weapons of war. Even if you go full on totalitarian your going to need a very loyal defensive guard to protect against assassins, and spend your life trapped in a bunker for fear that if you go outside so many people hating you means multiple attempts on your life. This is assuming you have advanced but not 'god-mode' level technology. If your have controllable mass-produced strong AI, smart nanotech, or big-brother level of spying power you may be better off, but if you have such game breaking power you can pretty much rule from anywhere. In short, military conquest of the world is not going to be a good idea. Your make a world where everyone resits you, assassins are everywhere, and either no work get's done, or work only gets done because you are the most evil of totalitarian governor everywhere that make people work via constant fear of death. Of course there is another option, you could just take over the world economically. You have technology worlds beyond what everyone else has after all. Sell it! First create some black box, so others can't produce whatever it is you sell, then set up a perfect monopoly on technology everyone wants. In the most benign scenario you become what legends like steve jobs and bill gates are/were, only three times as much. You have so much money you don't know what to do with it, everyone respects your genius, you can play on the big stage, and you don't really need to do anything but enjoy the easy life. If you really *must* control the governments, not just enjoy being the richest and most important person in the world, then you can always use your monopoly to control them. If the government doesn't go along with what you demand your instant-food-replicators will no longer be provided to that nation, and they can go back to having their population starve while everyone eats all the free easy food you are providing. Your super-computer come with backdoors that you can use to shut them off if someone doesn't cooperate; killing their economy etc. Once your technology is mandatory you have massive control to dictate terms to those who want it. If you do this politely and subtly enough people won't realize how much power you have, or if they do at least won't hate you enough to want to resist you because of it (again, look at the monopolies currently, Microsoft and apple have both had some practices we didn't like as consumers, both have tried to force their monopolies on the world through shade methods; but ultimately they provided the best products and we still used them even if we complained about their practices). This seems a better way to control more of the world, with you leading a much easier life and a higher chance of actually working, and as a minor added bonus, doesn't require a war that decimates the world population (you know, minor plus) :) [Answer] **Everywhere** is fine, where you have pretty fast internet. Why? Well, conquering that planet in a traditional way is mostly impossible without destroying way to much stuff. So consider this: Set up a specialized cat video web service and place sublime suggestive Orders inside. After you finished a survey about "who likes what cat videos the most", you can switch your suggestions from general friendliness to specific actions, especially "adopt a company selected cat for your home". With your financial reserves, you could easily set up homeless animal shelters *everywhere*, and now your suggestive videos suggest all humans to venture to your shelters and adopt one (may work with dogs too). These cats than have been bred to pass a special affinity to you food only to all childs. And they are kind of... fertile too. And they are trained superior in charming themselves into the hearts of all humans nearby. Now wait some cat-generations an suddenly you have a world full of people that own a cat of your bidding, which carve on your food and know how to look half-starving if they do not get a constant supply of your food. And of course you can always fall back to implementing enhanced harmony distribution devices into the cats to make people more friendly in general... you could modulate the purring by unharmful genetics engineering to be even more relaxing for a start. or make cat-poop send out pheromones that trigger happiness-hormone-production in the humans disposing it. Wait, that could backfire. And suddenly you can press whole countries to your bidding, just by shortening the supply of your cat-food, if they do warlike stuff. Every warmonger would consider his actions, if his beloved fur-ball start looking sad. I would say, this makes you effectively to the worlds most powerful person. Goal reached. [Answer] In the United States, some place where a couple hundred million can swing the state elections. * Sooner or later, you have to face the US. Do it from inside rather than from outside. * Meanwhile, the political and military power of the United States will defend your operations against outside interference. If you build the fusion power plant in some third world country, the US would be really suspicious. * Any premature sightings of your drones will be blamed on Area 51. * Reasonably decent infrastructure. [Answer] Starting in France is crucial, France is a extremely strategic spot thanks to the alps and the Pyrenees cutting off France from Spain and Italy. Sea blocks France from Britain and a small mountain range cuts off France from Germany, however the mountain range that protects France from Germany has a small gap in the northern area giving free access to France you protect that area and fortify it, you've got a great area to start world domination. Another reason to start in France is the Mediterranean sea a great spot to create a trading empire. After France I would take Germany, Italy, and Spain, each having strategical benefits. Italy has the alps to the north and is surrounded by sea if France ever falls to the enemy, you can use Italy as a backup while you regain control over France it is also useful for fishing. Spain is alright it´s best benefit is the strait of Gibraltar. You can use that and the area below the strait to gain control of trading through-out the Mediterranean, doing this can help strengthen your own empire and weaken the country´s within the Mediterranean. Germany is very good for farming it rains a lot and is covered with valleys and lowland. Use this to feed your empire. Next take Greece, the area around Greece is covered with water and islands great for fishing, you can also use Greece to control the black sea, use the black sea to penetrate deeper within the Asian continent, the Ukraine is also good for farming, use this to keep up with the growing concerns for food. By now you have most of the European continent by now do whatever you want, I would recommend taking control over the Baltic sea. Using the Mediterranean control the Seas! and make allies with many of the countries you plan to take over last, like japan, the USA and china make sure to treat the land to take over kindly and let them remain sovereign to a point if they make a move to rise up. crush them under your boot and make a example to anyone else thinking of rising up. Have fun taking over the world with you cat empire!:) ]
[Question] [ It's a staple in tabletop RPGs: "Long ago, the guilds ran everything, but then [insert event] made the people form a more centralized government". I want to make a medieval fantasy city-state civilization that is a satire of corporations, in that there is no central government only guilds, but I always get stuck because I have a hard time understanding who would make sure bridges go up, pavements are maintained and the that the water is running and healthy. I don't want a council who is recognized by the guilds, because that's too centralized, but more occasional coalitions between a few of the guilds that are done to complete certain projects. So, to focus it on one question, how would very expensive projects that need more resources than any one guild or individual is prepared to spend be financed in this anarcho syndacalism? Defense, aqueducts and pavements are very long term investments but a huge incentive for people to chose a city to live in, so everyone would agree it's important, but how would they pay for it? There are enornmous power gaps in this city. The mages who are specialized in creating magic items are the most wealthy guild in terms of revenue but they are dependant on other guilds for resources to make the items, defense and many other things like any other economy. [Answer] The people would pay for their services. Kind of like how our utilities work now. If you didn't pay, you get no service. So of course the richer neighborhoods will have better services than the poorer ones. Where are roads built? Where rich people need them. Who gets clean water? Those that can pay for it. The poor might get lucky in that a pipe with clean water will feed a neighborhood, but if it gets broke, it will likely be the last one on the list to get fixed. Police guild? If you don't have enough money to pay for services, don't bother reporting the crime, and better make sure you aren't suspected of any crimes against a much richer person, you'll lose. For many services a neighborhood might pool resources to get the service they need. All the shops along a road might pay to keep the road in good repair to encourage more shoppers to walk by their shops, or a middle class neighborhood might pay for some plumbing to have fresh water for the neighborhood and keep it running uninterrupted. [Answer] A question regarding how the guilds might afford large infrastructure projects might be more informative if you were to invert it somewhat- what large infrastructure projects could the guilds *not afford to ignore?* Their money is largely going to derive from trade, so strong trade links and safe trade routes will benefit the guilds and the general population. That's not the main reason you would build infrastructure though - it is also profitable. If the ferryman charges five silver to cross the river and you build a bridge and charge three silver to use it, you're going to make a lot of profit and probably put the ferry guy out of business, at which point you can charge *even more!* Likewise roads are usually freely used now, but in the past ( and in France ) there were many turnpike roads, privately maintained which travelers were charged for. Some guilds may have work that needs them to be able to bring in deep draft ships, so they'll need to maintain the harbour, keep it dredged, and to help finance that or maybe take a part of harbour fees in exchange. There is an economic web involved in all of this. Large infrastructure projects that aren't viable for the guilds won't get done, but if there is something that people can be charged for, then the rewards in doing so are likely to be sufficiently attractive to the mercantile. [Answer] There is a number of options that have been already touched upon. If there is a demand for a particular service, people will find a way to provide it. **Medieval caveat** Keep in mind that medieval cities often didn't deliver the services you mention in the first place. Especially water supply was a sore point even after it was recognized how important it is - and that took a long time! **Localized services** Some of the items you've brought up (notably pavements) can and will be provided by the guilds themselves in their places of interest. Nobody wants to have a beautiful guildhouse surrounded by a swamp; similarly, places of trade need roads of at least some quality. People built roads without a central authority all throughout history as they do now. Guilds can assume responsibility for specific parts of the city, with the rest being left to whoever is inclined to maintain them; probably whoever is living there or has to pass through. The potential problem here is a hodgepodge of roads and pavings of highly varying quality and nature (although any medieval fantasy city is likely to have that anyway). Streets and roads can feature tolls, possibly applying only for some loads and travelers (e.g. wagons only) and can have weird rules for usage. Make sure to emphasize this during chases - in some places the heroes slip on the slick stones, in others they have to slow down to throw in a copper to pass. In yet others they can cross but must stay silent etc. **True Roman bread for true Romans** Guilds (hopefully) don't just focus on hoarding money, they also take care of their members and help out the wider community. They don't have to be altruistic at all - it makes perfect business sense to be seen doing good, especially if the guild members also profit. The flipside of this approach is that much like today, the highly visible and popular projects will have priority over the necessary and boring. The powerful guilds are also likely to try going at major projects alone, even if they can't really finish them. The lure of great income and/or prestige has brought many organizations down - and many will be eager to help them go down. **Magic** As pointed out by others, magic can make many tasks easier, especially in construction. You could also have priests cast repeated purifying spells on the water sources to supply the masses with clean water. (If you don't want to go outside of the guild structure, you can make those priests/magic users another type of guild, that everybody contributes to if they want water... just a thought.) The downside of this is giving magic users a lot more influence and at the same time annoyance because they serve as common laborers. What could possibly go wrong? **Collections** A public fund could gather the money and resources needed for a vital piece of infrastructure. The project will be managed by a known group of people and may be well-defined in advance. This approach can run into trouble when costs inevitably overshoot the budget, or someone refuses to pay up their IOU, do the promised work, etc. Public opinion can change and leave the project half-financed. **Part-time job** A number of guilds has agreed to cooperate on a long-term project. Each of them will work on it and finance it for a month or a number of months, taking turns. There is of course the risk of some contributors dragging their feet, doing sub-par work or even sabotaging others to make their work shine more. [Answer] ## Taxes! "Guild fees" All governments require a source of income to fund projects, even fundamental ones. Each member of the guild must pay a yearly, weekly or daily fee to be recognized as a member. However, large projects may be out of the scope of a single guild. ### Mutual benefit and time/gain Why *exactly* do they need the bridge. Is it merely for convenience sake? If so, the bridge won't likely be funded in a realistic amount of time, however, if the bridge happens to create a several hundred mile shortcut to a major trading site, then all the guilds interested in improving trade *as well as* the trading site will throw cash (and bricks) at it like crazy. Unfortunately, the length of time each project requires can hinder their fulfillment. Bridges, roads and other structures can take a while to build and roads also have to be maintained albeit not as much as in modern times. In other words, the larger the project, the more resources and higher return needed. ### Magical paving All is not lost! Surely magic, enabling fireballs, explosions and other assorted deadliness, will have *some* method of improving build times. Earth wizards just became the most boring. Instead of laying countless bricks by hand and using heavy equipment to bring up bridges, 10-20 powerful wizards, via spells, rituals or other, simply and literally raise a bridge from the ground or flatten the roads while hardening them. Definitely look for additional reading related to government project funding. [Answer] Err... You want a medieval city with running, healthy water? Now that IS fantasy! Now on bridges, why not simply charge a toll for anyone who wants to use it? It's hardly unknown even today: most if not all of the bridges in the SF Bay Area charge tolls <http://www.batolls.info/> as do ones in the New York metro area <https://www.panynj.gov/bridges-tunnels/tolls.html> Same idea could be extended to highways and aqueducts: if people want water delivered, they pay a charge, as is done in many areas today. The people who invest the initial capital of course make a profit from it. This just requires that some entities - nobles, bankers, the guilds themselves - have access to the capital, and a long enough investment horizon. Indeed, this is the way a lot of public capital construction is financed in the US (not sure about other countries). The state or local government doesn't put up the money directly; it issues bonds to raise the money, which are paid off over many years, typically through tax revenue, but it could easily be from income generated by the project itself. PS: Some roads in medieval times actually were constructed this way, by groups organized for the purpose, who were recompensed by collecting tolls from users: en.wikipedia.org/wiki/Toll\_road#Middle\_ages Same was true in early America: en.wikipedia.org/wiki/Toll\_roads\_in\_the\_United\_States [Answer] To completely de-centralize the administration of public services, each guild could own a portion of the land in your city-state and operate that land as its own sub-state. A guild's state would have to strike a financial balance between focusing on revenue-generating guild operations and the expense of forming an environment which is attractive enough to bring in the kind of citizens which lend to the guild's ethos. Guilds are therefore competing to some degree over citizens, which drives them to provide better living conditions. Guilds which are too small to provide for all of their citizens' needs on their own could buy the services of larger neighboring guilds. Guilds on the city-state's border would get discounts on interior states' military services, as they are the first line of defense against invaders and therefore act as the city-state's protectors. Guilds owning land through which aqueducts pass are paid by guilds farther down the duct so that water is permitted to flow to them, and guilds without aqueduct access pay to access water from those with aqueducts. Each guild has something the rest of the city-state needs, be it the resources of its land or the guild's particular services and products. Everything is driven by profit and an implied code of honorable business conduct. Guilds straying from this code in self-interest are shunned, eventually withering and being absorbed by neighboring guilds. I won't speculate on the success of such a system in the real world, but as far as fiction goes this arrangement gives you tremendous narrative flexibility and, IMO, is generally believable. ]
[Question] [ Would a centaur eat meat? Humans do (usually) eat meat, but horses are vegetarians. Would they be omnivores, carnivores, or herbivores? [Answer] **Omnivores.** But of course, they could be either three. I asked a horse-owning friend, who looked at me oddly (as usual), but told me about a book she read: [Deadly Equines](http://rads.stackoverflow.com/amzn/click/1590480031), documenting 4,000 years of meat-eating horses on every single continent (including Antarctica). She notes that some of them were in desperation - including human - during things like an expedition, but others are well documented cases of horses that eat meat. It seemed pre-cooked meat was best and most common, just like it is for us, but not exclusive. [Answer] Yes centaurs would be able to eat meat. Their stomachs are a hybrid of a human and a horse, both a gastric and equine colic. The way centaurs are built, it would be impossible to graze upon grass all day. They are typically seen hunting their game with bows and spears. They are very fond of pairing this with Greek wine. It should also be noted that they can eat as many pizzas and hamburgers as they want without any side effects whatsoever. [Answer] I assume that centaurs have the best combination of horse and human organs. Someone was saying that they might have horse-sized human organs too but that's a different story. But if this is what we're gonna assume, then I see no reason they couldn't eat meat AND vegetation with "human" stomachs. I think centaurs would be omnivores. It'd make sense thinking survival-wise. When they obviously need a whole lot of food/water, it'd be a little stupid for them to pick either or. Hunting game like deer could mean a whole lot of meat, but gathering could go with it to fill them up and provide better nutrition. I guess a centaur could live off of plants alone if he's some Chiron hippie-like centaur and doesn't feel much like hunting. [Answer] Biologically, I'm unsure, but from the mythology I doubt they'd have an ethical or moral objection. From what I can tell about the traditional mythology surrounding centaurs, they weren't exactly very, ahem, considerate of their fellow beings, and they were considered amazing hunters. ]
[Question] [ Assumptions: * We have materials that can withstand the temperatures/pressures/acidity of Venus. * We can get to Venus and back reasonably easily (NASA does shuttles every 3 months). Here is Venus: ![enter image description here](https://i.stack.imgur.com/CF4gVm.png) From what I know, [water boils at 100 C](http://en.wikipedia.org/wiki/Water) (at sea level on Earth) and the [pressure on Venus at 40.5 km is the same as on Earth at sea level](http://www.astro.wisc.edu/~townsend/resource/teaching/diploma/venus-p.gif). Finally, the [temperature on Venus at ~40 km is 100 C](http://www.realclimate.org/wp-content/uploads/clouddeck.jpg). So would this work: ![enter image description here](https://i.stack.imgur.com/3Lb3cm.png) Water is heated to gas, goes through turbine and makes electricity and then gets pumped back up and cools to liquid and then the cycle goes again. Would this create energy without using more than is required? Next question, how would we get that energy back to Earth? I have a semi-idea: * Incredibly powerful lasers, onto solar panels on the Earth. + These could shine either visible light, or maybe a wavelength on the electromagnetic spectrum that doesn't get absorbed by the atmosphere. [Answer] This is a horrible idea, not because it wouldn't work (there have been [similar power-generation schemes](http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion) in Earth's oceans) but because the atmosphere of Venus is hellish: it's [made of sulphuric acid](http://en.wikipedia.org/wiki/Atmosphere_of_Venus) and winds blow at hundreds of miles per hour. There's hardly a spot in the solar system less friendly to a water-containing turbine system. If you have the technology to put all those materials in orbit around Venus and somehow drop them into the atmosphere (float them?), just use the same resources to build a bunch of space-based mirrors and/or solar panels. You'll get *way* more power, with *way* less trouble. [Answer] This would actually work as you describe (assuming all your material/technology requirements are met, as you do). However, there is a practical issue. Unless you have some super-high-density energy storage medium, you will probably be beaming your energy back as a maser or laser (also as you describe). Let's stop and think for a second. Where is the energy to support that atmospheric temperature gradient coming from? The Sun of course! The Sun heats the planet/atmosphere, and the heat is trapped by the greenhouse effect. This effectively makes your power-generation scheme a roundabout solar generator. If you have the technology to efficiently convert your energy beam into usable power, then you also have the technology to efficiently convert raw sunlight into power. Solar panels will be much more efficient at generating power: the theoretical limits are somewhere around 50%, while the thermal efficiency limits on a thermal engine with a hot-side temperature of only 100 C (assuming a cold-side temperature near 0 C) is much lower, around 25% (even discounting the mechanical and secondary conversion losses). [Answer] It is possible however a horribly inefficient use of materials. Venus' atmosphere contains 96.5% CO2, 3.4% Nitrogen and other gasses with the major one being, sulfur dioxide. The atmospheric pressure is also **93-98** times more than earth, the same as being about 1km underwater. A probe has been crushed 18km above the surface. Also, the surface temperature is **450** degrees celsius which can melt lead so goodbye cheap radiation shielding. And the nice fluffy clouds you see are **sulphuric acid**. **As you said we have such materials but would it not be easier to build something that is efficient?** If you want to build something that needs to get a lot of energy then I would suggest building a massive solar array in space because it will require less maintenance, is a lot more "human" friendly and probably costs a lot fewer resources. To send the energy back to earth you could: 1. Use a laser. 2. Save the energy in nano-tube power banks. 3. You are currently using a semi-solar solution but if you convert to full solar power you will have a lot more energy to work with. \*semi-solar because the greenhouse gasses which keep the warmth from the sun that in the end warms the water. Also: because the pressure is a lot higher your water will only start boiling at a mere 300 degrees celsius **If you are however determined to build on venus I would suggest:** * Shipping the energy in batteries. You can use the sulphuric acid as an electrolyte. * You can use the sulphuric acid to react with metals and create hydrogen gas. This gas is extremely flammable and can be used to power a "conventional" engine. **Bonus point:** Theoretically you could terraform the planet to suit your need but this would be very expensive but afterwards, could be used as a hospitable colonization for humans without needing to transport the energy. [Answer] Even with the assumptions you made this is still not a good idea. What you described probably wouldn't work. I might be mistaking but it sounds like violating 2nd law of thermodynamics. In geothermal plants on earth pressure is not as high as Venus. Maybe do a bit more research on geothermal electricity. There is another way however that you can generate electricity on Venus. By directing convection flows. Have a look at [solar updraft towers](http://www.wikipedia.org/wiki/Solar_updraft_tower) But these are very inefficient method for electricity generation. The more I think about it, it makes no sense to generate electricity on Venus. And there are a lot better ways to do in earth orbit or moon. If you want to have a factory on Venus and want it to make sense scientifically, why not some floating factories extracting minerals (maybe sulfur) and shipping them to earth. Have a look at [Venus floating cities](http://www.wikipedia.org/wiki/Colonization_of_Venus). The air in the city is less dense than Venus atmosphere so it floats. ]
[Question] [ This world has an incredibly high humidity rate all year round and I'm curious as to what - if any - evolutional changes might occur in human skin. Would it just be less porous or would there be a more drastic effect? edit: humidity might not have been the right way to describe this. I really mean a planet where the air has an incredibly high moisture content and sort of exists as a vapour. [Answer] With information provided, your answer could go either way. Nature follows the path of least resistance in most all cases. Humans being mammals one possible route is they might lose their sweat glands and grow short and thick, but sparse hair over their entire body to wick away excess moisture. morphology may change, meaning spaces like spaces between toes may disappear preventing places for fungus to take hold. stance may be altered to accommodate a wide space at the groin to eliminate the same or internalise sexual organs with a cloaca. Ears may begin to shrink to thwart infections, eyes may grow larger to capture more light. All of this assumes evolution without interference from modern tech to mitigate the evolutionary process. [Answer] 1. **No cooling by sweating.** Humans cool off by sweating. In 99% humidity sweat does not evaporate so that will not work. The sweat glands responsible for putting out water to cool us will no longer have an adaptive functon. 2. **Greasier**. A layer of oil on skin prevents water ingress. Long distance swimmers grease their bodies to augment the oil layer. Hippos accomplish this with a greasy pink skin secretion. Your people would be greasy, and possibly pink. 3. **Redundant skin folds.** Since sweating is not useful, your people must cool off some other way - and I am assuming a place with 99% humidity is pretty warm. I assert they would do so by increasing surface area. They would have many redundant skin folds exposed to the breeze. They would look much like this Shar-pei dog. But bipedal I am sure. [![shar pei puppy](https://i.stack.imgur.com/KPss2.jpg)](https://i.stack.imgur.com/KPss2.jpg) [source](https://www.facebook.com/TOPSharPei/posts/quality-chinese-shar-pei-puppies-with-pcci-papers-health-recordsheavy-wrinkled-m/2981425378747760/) Also greasy and pink; see #2. ]
[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about worldbuilding, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 1 year ago. [Improve this question](/posts/231567/edit) I'm working on a backstory for a science fiction setting and one of the factions are meant to have started out as a worldwide network of political dissidents operating in a sort of parallel civilization for generations. As time goes on, they grow fed up with the rest of the world and see themselves as unable to change things for the better in any meaningful or ethical way. With nowhere else to go, they look up and see their new home. They pool their resources to build a set of underground launch silos and spaceships, making great effort to ensure that no one is found. When the day of their exodus arrives, they surprise the rest of the world when a large number of spaceships suddenly take off from hidden launch silos scattered around the world and converge on the moon. Each ship carries settlers, supplies and equipment for rapidly building a sustainable Lunar colony from which they declare independence from Earth. What I want to know is how would military forces of a modern technology level respond to this mass launch. How quickly would they become aware of these launches? Is it possible some of these ships will be shot down? Or will that surprise window be enough for them to make it into space untouched? Or would such an aggressive response even happen? [Answer] The USA would become aware of these launches almost immediately, via the [Space-Based Infrared System](https://en.wikipedia.org/wiki/Space-Based_Infrared_System) of satellites. If there were any launches from Russia, China, North Korea or Iran, this would cause an immediate rise in the nuclear alert level, with some risk of mistaken nuclear war. I don't know if Russia or China have similar early-warning systems; the USSR certainly did before it fell. Assuming that an accidental nuclear war does not break out, there isn't much in the way of plans for intercepting an escape attempt from Earth, so most of your rockets are likely to make it to the Moon. However, this scenario does seem to be harder than necessary. Building large rockets, capable of carrying significant cargo to the Moon, is quite difficult and *extremely* expensive. Look up the history of [SpaceX](https://en.wikipedia.org/wiki/SpaceX), who have had many failures while developing in the open, and making use of a very wide range of commercial engineering suppliers and resources. Consider how much harder it would be to do this secretly. You're also going to need a *lot* of rockets to carry enough stuff to the Moon to set up a self-sustaining colony. That's a bit harder than on Mars, because of the total lack of atmosphere and the need to burrow fairly deep to avoid the temperature swings from the Moon's slow rotation. Can you plausibly build a hundred or so rockets equivalent to the SpaceX Starship+Super-Heavy, without ever being spotted testing one, and then launch all of them successfully and simultaneously? Consider how often rocket launches are delayed or postponed. The US' satellites *will* spot your test launches. A far easier way to do this would be to set up a company like SpaceX, develop the capability in the open, and then smuggle your people out of their repressive countries and set up a private lunar colony. Smuggling people is a lot easier than building 300' tall rockets in secrecy. [Answer] In addition to the answer by [John](https://worldbuilding.stackexchange.com/questions/231567/how-would-modern-militaries-respond-to-a-large-number-of-unknown-spaceships-sudd/231571#231571) regarding missile warning systems ("Where does the rocket impact if it cuts the engines in 30 seconds? In 60 seconds? ..."), you can expect: * Depending on the trajectory, *attempts* to shoot them down with [ABM](https://en.wikipedia.org/wiki/Anti-ballistic_missile). These *may* fail as the spacecraft travel towards the Moon, since ABM are for lower altitudes than that. Or they work if the geometry fits. * Feverish calculations about where the lower stages will crash, unless your craft are [SSTO](https://en.wikipedia.org/wiki/Single-stage-to-orbit). Possibly air raid warnings where they will come down, if the countries are organized enough to do that from a peacetime footing. Or the sirens only start *after* the lower stages hit Earth. * Panic reaction in the air traffic control system, [grounding all airline flights](https://edition.cnn.com/2022/01/11/business/faa-ground-stop-norad-north-korea/index.html). [Answer] It is highly unlikely that the whole ordeal will not be found out by the militaries until the lauch day. Let's assume they used a public company to test the rockets, which is less suspicious. When you are buying immense amounts of aluminium to build hundreds of space craft, you will get noticed. There is near zero chance that you will not caught until the launch. Though, if you really want to, this can happen still happen in partial secrecy. Military notices the anormaly. Finds the source and places some spies in to monitor the situtation. Militaries are not like police, they don't immediately respond to developments unless they require urgent action. After spies have reported that they are peaceful, there will be a report to the president. President might simply say let them continue in secret while monitoring their progress. As the ships take to the orbit, the president will be watching, knowing that a strong opposition has left the Earth. [Answer] The thing is, how would they ***NOT*** be aware of the launch years into advance? Let's suppose for your sake that they were at a point where the technology to land on the moon is more readily accessible than the technology to put a satellite into orbit is available today. A full fraction of world wide political dissident? I will try to not be too political, but those would be under heavy scrutiny of the intelligence of all the states. Even small organisation today have a lot surveillance in their back, with infiltrated agent and electronic surveillance. It's for a reason even small groups often get caught planning small scale terrorist attacks, simply because even when not infiltrated, when you see them order weapon in bulk you know something is up. So when your intel tell you they are buying en masse material to build ICBMs, everybody will watch very closely that you are actually trying to leave earth and not kill everybody. (because rocket science is really just missile science) There is also no way that all of the world political dissidents starting to hoard the material for an exodus is not an open secret if not a well known fact. This is the kind of operation that asks for industrial scale work. Humans suck at keeping secrets and with anything involving more than a couple of people, it is guaranteed that somebody will spill the beans by themselves for all kinds of reasons. (and I don't know if it's in the scope of your question, but how they get the resources is a big can of worm in itself, especially if they are dissidents. If they have the resources to do an exodus why wouldn't they change the world order?) In conclusion, the states for the world wouldn't do shit when the rockets fly because they would have known the date of lift off years in advance and chose not to stop them because it was cheaper to let them leave than kill them all. [Answer] Even if the world militaries *could* do something (they couldn't, because missile defenses are designed to shoot down missiles when they come down, not when they go up), they probably wouldn't. Because **what this organization is doing isn't illegal**, or at least not so illegal that it warrants the use of deadly force. The [outer space treaty](https://en.wikipedia.org/wiki/Outer_Space_Treaty) guarantees that every nation on Earth has the right to fly to the moon if they want to. The treaty only considers nations, not private organizations. That's because when the treaty was written, no private organization had the means to travel to space. With the recent ambitions of private sector companies to make use of space, it has become a topic of debate about if and how the outer space treaty can be applied to non-state actors and if it might need some amendments for this. But until then, there is really no reason why anyone would interfere with anyone's moon project. And even if some countries would have something against an unlicensed rocket launch from within their borders (it probably violates a dozen laws and regulation regarding airspace use), this would not be an infraction justifying the killing of everyone on board these rockets. What is forbidden, though, is claiming sovereignty of space. So if the organization later declares that their moon colony is now an independent state, they would probably not get international recognition so easily. But that's a topic for a different question. ]
[Question] [ I'm writing fiction in a shared world that I have some control over, and for my own benefit I'm trying to figure out a reason why the Dwarves in this world wouldn't be 'mature' until they'd reached 50. In this world, the absolute maximum age of a dwarf is ~350. I'm going to say they mature at the same rate as humans do until they hit the early/preteens then everything slows down until around 50 years of age then progresses into full maturity around ~100 perhaps. I can't change the ~50 cut-off/transition into adulthood, but I can try to make sense of it. I know for humans [adolescence](https://en.wikipedia.org/wiki/Adolescence) is a period of change both physically and psychological change, and various evolutionary and environmental pressures act to balance when it starts and ends. However, I'm mainly considering things like going through a [reckless/rebellious phase](https://en.wikipedia.org/wiki/Teenage_rebellion) as the focus of what I want to understand, and why that mental rewiring would last so much longer than in humans? For the purposes of this question Dwarves in this world have average heights between 3'5" and 4'11, but outliers exist on either end. They're also significantly heavier than the equivalent human of the same height would be. [Answer] **Cooperativity.** Pre-reproductive age children are historically super useful for a family. Chiefly and very importantly, prereproductive age humans can watch their younger siblings, who have a penchant for being eaten by leopards and falling into holes. Mothers can concentrate on babies. Fathers can do what they do. Some birds use prereproductive aged children in a similar way - the sibling from the prior year sticks around to help care for the new babies. Once your kids are grown they go to work on their own babies and are less help. So too the dwarves. Having a prolonged nonreproductive phase helped improve the fitness of those carrying that gene. Perhaps in evolutionary ages past dwarves had high child mortality rates, and the presence of nonreproductive siblings reduced that mortality rate. [Answer] ## Pre-puberty neoteny Lots of animals have stretched their juvenile phase, including many insects, humans, and most importantly, axolotls. The reasons vary, but include: * Environmental pressures. This applies especially if maturation is linked with a marked change in living conditions, like sprouting wings or going from gills to lungs. So, for example, your dwarves may develop very large and luscious beards at maturity, but these get caught in cogs, so un-bearded individuals may have advantages that favour a delay of the onset of puberty[1]. Or maybe it's a neurological change with behavioural effects - adult dwarves become very set in their ways, and individuals who can retain their youthful creativity for longer are at an advantage as times become increasingly industrialised. * Sexual selection. This is often touted as the explanation for human neoteny, which has pretty disturbing implications about our hominid ancestors if you ask me. However this doesn't work if you want to keep your characters pre-pubescent - this type of neoteny is usually linked with progenesis (reaching sexual maturity whilst retaining a juvenile look). * Nutritional limitations. Some animals delay puberty until certain nutrients are available, or until the warm season. Maybe the hormone that triggers puberty requires exposure to the sun, like vitamin D. Since the dwarves' ancestors elected to live underground, it now takes many years to bioaccumulate a sufficient amount to kickstart puberty. Or you can flip it if you prefer your characters to have adventures on the surface: deep dwarves mature much faster, and choosing to live on the surface as a "permanent teenager" is seen is a sign of irresponsibility and weak character, cutting you off from the higher strata of dwarf society. --- [1] No *of course* they can't shave them. [Answer] **High adult fertility/reproduction rate** In mammals (and many other vertebrates) there is a strong evolutionary pressure to reach sexual maturity at a younger age and start reproducing - because, otherwise, with low reproduction rates, the species may not have a chance. This process works differently in insects. They may spend most of their lives in larva stage, reaching adulthood late in their lifetimes. Why? Because they can afford it - reproduction rates in adults can more than compensate the numbers of larvae that are lost. [Answer] **Beard Castration** Beards play a huge biological role for Dwarfs. The beard is where the chemicals to transition from pre-teen to adult are created. Shaving a dwarf is like castrating a human. It inhibits growth in one direction. Only it is less painful and more reversible than chopping off the gonads. This fact is not common knowledge among dwarfs because. . . Beards play a huge cultural role too. A dwarf with a beard is one who has finished their First Craftsmanship Examination. If your blacksmith, mason, or carpenter has a bushy beard you can be sure his/her/their goods are approved for quality by the Central Guild. If your blacksmith, mason, or carpenter is clean shaven, they are still an apprentice, and could get in trouble for selling their wares. Now a human apprentice might graduate in five years. But dwarfs are such sticklers for precision, it usually takes 50 years for the apprentice to graduate. Then they are allowed to grow a beard and allowed to mature. **On "Rebellious Teenagers":** If you are worried 50 years of rebellion is too much, then I suggest your rebellious dwarf teenagers are not so rebellious at all. In fact that are exactly as rebellious as normal human adults. The only seem rebellious compared to adult dwarfs who follow procedure and tradition to the extent of having no discernible soul. [Answer] We live in a culture that has expectations of what maturity is and what it means and which privileges are granted with it. These expectations have little to do with biological reality. However, they interfere with your ability to design a species where these things are important elements of the story. Strictly speaking, there is no such thing as "teenager-dom". Puberty occurs, and a human is functionally an adult. If this is the sort of detail you are concerned with, we know quite a bit about it. Larger animals tend to take longer to become adults, smaller ones tend towards less time. Animals which are in great danger from their environment will become physically capable early... dolphins swim immediately or they can drown, antelopes walk and run within minutes due to predation. K and r strategy also plays quite a bit into it. If instead you are concerned with, for instance, why we see many 40 and 50 yr olds today who behave irresponsibly, who are unable to care for themselves despite no obvious deficiencies, and so forth... this is because they belong to a society that through design or accident doesn't require them to do these things. They will never "grow up". It may even be somewhat true that if a person doesn't do that by their 20s or so, they may even become incapable of it. If instead you believe that there is this magical phase of human development where a person has achieved reproductive capability, but still has all sorts of novel growth still ahead of them, physical, neurological, emotional, and psychological... well, just import that wholesale into your story, and these dwarves can be surrogate humans for story-telling purposes. > > However, I'm mainly considering things like going through a reckless/rebellious phase > > > Such may actually have a true biological origin, in that species that have discovered a new geography or niche would do well if offspring are spurred to strike out on their own and make new territorial claims quickly. Humans experienced this several times in our deep past. But the biological tendency is slight, and tends to be maladaptive in the environment we find ourselves in today. Everything else is sociological, though there are few theories I find plausible. Depending on a person's politics they might decide that there is an inherent need for progress, and that an older generation is too stodgy and ossified to embrace change. Or they might decide that youth has been corrupted, and does not share the values and principles of ancestors. Do any of these really work for your story though? Biologically, did this species experience a prehistorical time when they had new continents and environments to conquer, so much so that the tendency towards rebellion was genetically hard-coded in their neurology? Do the socio-political things sound good for the story you're telling? They don't have to have a rebellious phase to make them believable, and they don't have to have one to make a proposed adolescence plausible. Do you need this for a plot point? In other ages and places, stories about youth would have had them prone to other personality flaws. Carelessness/recklessness, foolishness, gullibility. Those (and others) might take the place of a rebellious attitude. ]
[Question] [ My story has a country/society made up of mostly shapeshifters. How shapeshifting works is that once someone turns 21 they are allowed the gift of shapeshifting through an advance technology. They can't choose what they get, it could be anywhere from a blue whale all the way to at least something with a brain. Anyone who registers for a morph must receive a 'sticker' which (depending on the morph) is usually just a small device which would trigger a' looker'. Which is basically a device which can identify people in morph, most look like something along the lines of speedometer police scanner. The problem there are illegal forms of getting a morph without having to having to get a sticker, meaning it's sometimes really difficult to tell if that pigeon that just landed on your lawn is just a bird or actually a man. Also the most common morphs are usually animals with backbones, but invertebrates morphs such as bugs do also exist though. Note: It's completely legal to kill someone in morph if they're invading your property, as it doesn't actually kill the person only the morph, someone killed in morph just simply turns back. Also (besides morphing) this setting only has modern day technology available. Edit: How the technology works is that tiny microscopic nanobots flow through the bloodstream and can kinda turn a switch in the human body from animal back to human. This is why the biggest size limit would be something along the lines of a flea. [Answer] It depends on what sets them apart from what they're meant to shift into. Examples from folklore and mythology. Werewolves fall into a dozen or more 'lineages'. The Greek Lycanthrope was effectively a man cursed by a god to turn into a wolf. As this was a curse, you can expect that they retained if not human level intelligence, then at least their memories. Germanic werewolves often took up the mantle of their own volition. Depending on the exact folk tale involved, they either had to drink water from the paw print of a wolf, or they have to wear the pelt of a wolf they killed with their bare hands. This is thus a voluntary change. In the case of 'wearing the pelt', they started out clumsy and their wolf form was just slightly larger and far more aggressive than natural wolves--they also had to hide their wolf pelt, so you could find it and lather it in rock salt to make changing agonizing. In the case drinking from the paw print, they would be almost indistinguishable from a natural wolf, but would have an intelligence in their eyes and used tactics unheard of with natural wolves. My point here, is that there's something that sets them apart. If you take modern day technology into account, you're apt to find even more differences. Suggestions: * a higher or lower body temperature than natural creatures * an imperfect shift (especially with less experienced shifters), where there are some 'abnormalities'. Think wings with abnormally large feathers, or claws that are either misshapen or the wrong length/colour. * an odd glimmer in their eye, either their iris or their pupil. * odd body language or sounds considered unnatural to the species. Just because they can shift, doesn't mean they understand the nuances of communicating in their shift's language. Think pigeons that make odd sounds, or dogs that can't communicate with other dogs. * blood samples. They can shift into the species. Does that mean they carry the species' DNA? * how does the nanotech that allows them to shift affect them in human form and while shifted? Does it slowly impart bits and pieces of the shift? Rat-shifters slowly starting to hate the light or being able to navigate mazes with relative ease? Dog/wolf-shifters becoming more pack oriented? Perhaps slowly affecting their nails and joints and height and voice? If you apply scientists attention to detail and the scientific method of dozens if not hundreds of people finding this new avenue of applied science/tech? There's no way they won't find ways to differentiate them. Anything from 'one less bone in their left small toe' (from My Hero Academia) to 'distress markers in their DNA' to 'sensors that detect nano-tech'. But, that all depends on the specifics of how these things work and what little tells you want to leave in. [Answer] **Magnetic Weapons** The way you describe this technology working is that this is accomplished via nanobots in the bloodstream using some form of futuristic technology to change the subject to an animal. To change back, you activate the nanobots. Now, let us suppose that the nanobots were subjected to a localized electro-magnetic wave which completely wiped the nanobot's memory. That would render the nanobots incapable of functioning and lock down the subject to whatever shift they were occupying at the time. Not to mention that, given the fried nanobots, it may be impossible for them to return to their original form even if they had someone nearby to give them a fresh injection of these nanobots, unless those were keyed beforehand. Needless to say, this would be very bad. Very, very bad. So, let's say you had a defensive system which incorporated this weapon. The mere *threat* of it should be more than enough to deter all the would-be intruders, except for the most determined and well equipped, but any target which would attract such intruders should have much more secure defenses as well. One final point - electromagnetic shielding isn't possible with regard to nanobots. EM shielding relies, on other things, on material thickness, and a shielding a few nanometers thick won't stop a sufficiently powerful magnetic wave. [Answer] # Assume Everything is a Shifter You realize that you there isn't going to be a reliable way to secure against shifters while still allowing not shifters access. So you decide nothing gets access, no insect, cat, bird or any other form of life will be allowed into your home, yard, property at all. Only the security personnel and residents of the home are allowed in, and even they require authentication (passwords, secret phrases, physical keys etc.) to get into the property, as it is still possible that one could shift into a human too (or just wear a disguise). [Answer] Trigger on anything large enough to be a morph. Of course you have the usual sensors. Pressure pads on your front walk. Things that detect a door or window opening when it should not, just for example. But you want earlier warning than when the unfriendly is already forcing open your bathroom window. It is simple to make motion detectors that are extremely hard to bypass. For close to the ground, you use capacitance changes in a wire fence. These can work for the areas within about 2 meters of any fence, structure, the roof, etc. It can be set so that anything with more than a few grams of water or metal will trigger it. Or it can be made somewhat less sensitive, if your rose bushes waving in the wind are setting it off. For flying critters, you put up fish-eye lenses and detect changes from one frame to the next. You can do some jim-jam with the optical focus length, so clouds don’t trigger it. Slightly more sophisticated could be infrared lasers doing nice spirals, with detectors sensing changes in the reflection from the surroundings. You can set this so it only senses stuff within some maximum range. Infrared so that most people can’t see it to avoid it. It’s the same general thing that comes out of some TV remote controls. It range-finds by having crossing beams and triangulating. Won’t be harming anybody’s vision. Hard to bypass. Once triggered you have choices. First, the system alerts the homeowner through his cell phone. Then there is probably some kind of warning. Maybe alarms, flashing lights, etc. Depending on how concerned you are about neighbor kids, wild animals, the postman, etc., maybe you look through your phone before moving to harsher methods. You need cameras at strategic locations covering the entire exterior. If you have a human at your front door, then you change things over to the usual things for that. Check if you know them, if they are selling something, if they are a charity, if they are the police, etc. If it appears to be an animal, you might hit it with a squirt of water to try to scare it away. Or extra loud sirens, though you need to be concerned with your neighbors complaining if the siren goes off frequently. You could have other amusing ways of discouraging animals that start with non-harmful and work their way up. I’m thinking a big flyswatter coming out of a trap door and giving the wayward bunny a big slap. If that critter that looks like a rottweiler is not deterred by sirens, getting squirted, and getting told over loudspeakers “Bad dog! Go home!” then maybe you need other methods. Possibly you call the police, who presumably are aware of morphs. Or possibly you move to various “Home Alone” methodologies. Or maybe you move on to lethal stuff. [Answer] **How to Catch a Human That Might be a Flea or a Cat or a Bird?** Look out for human tendencies in animals: Any sign of reading or having apparent understanding of human writing. Observance of signs. Indifference to fire. Laughing. Also look out for animals acting unconventionally/suspiciously. Eg. That goat that tried to get in the front door earlier, or that fly that keeps going inside my top. If it's mostly tiny creatures you're worried about getting into the house you'd probably need some sort of bug-zapper lazer setup. Also, if it's nanobots then perhaps a giant magnet would do the trick to de-morph them. And if it's nanobots, they should only be allowed to be activated by shouting "It's Morphin Time!" and if someone does it without shouting first they are a baddie. [Answer] I believe you just answered your own question and set up the perfect security system. I do understand that these morphs don't have a sticker, and you don't know if they are really just animals. OK, I will get to that. Let's walk through this: 1. We want security from bad people, just like we have here on earth. No one is allowed to just walk into your house, even if they're an ant or a dog form. OK, the way we handle that on earth is with a deterrent. Something that alarms when they come, and calls a professional (police officer); or some people just take care of it themselves with a gun. After all, they are intruders. The important point here is, as humans, we really are not concerned with the safety or well-being of the intruder. So, that should be the same with a shape-shifted morph. We don't care about the ant's well-being, or the dog's well-being if they are an intruder. Is that logical? But there is a slight difference because a human form and a morph form are physically different. But that's where the difference ends. There is no moral difference, or rational difference in the way an intruder is handled based on their shape or size. What *is* different is the professional we call, or the weapon we use to protect ourselves. For a human, we call the police, or use a gun. For a morph, we call the exterminator, or use whatever bug spray or taser we would handle the problem as a creature. We have an advantage against morphs as humans because we have hands. There are really no morphs which could reasonable get into your house that you can't overpower. A bear isn't getting in, you have doors. They're tough, but doors are generally tougher. If you have cheap doors and windows, and a morph bear is your worry? well then, this question is looking for the security options. Those are your options: tough doors and windows at the hardware store. So thinking about what morphs *could* be getting into your house, they will pretty much be limited to bugs and lizards and very small critters that you can step on. Bigger critters don't have hands to work a door knob. And even if they did, just buy a better door knob, or lock the door. 2. Let's look at the legal implications. There are none. Your world absolutely allows you to treat a n animal morph just like an animal, because no one gets hurt. **Conclusion:** Security against a morphed person is identical to the security against the real creature they have the shape of. Big things are stopped by walls and doors and windows with locks. Small things are stopped with poison or exterminators or your shoe. Ant poison is available to just sprinkle on the floor at your doorstep. And if they do sneak in and get big, then they are humans. That security is the police, or a gun. In effect, nothing at all changes. The way you secure your home against any "thing" today, is the way you secure your home against any "morph-thing" as well. [Answer] **there isn't a problem with how to identify the morph, but there are some problems with the law and government's protocol here** 1)I believe there is some problem here about the law which you can't kill invaders. consider this: if front of my house's door, I leave some tools and an invader come and kill him/her self with that. do I perform any action against the law? in my opinion, the answer is no! in some cases in defense of the act of invaders or a law breaker, they can just say they aren't informed about the danger or the law and that's why they are harmed or perform such an action (like invading a house that security can kill or harm them). so u can just hang a sign from your door or somewhere that they can see to inform them and then use any security application that can kill even invasion of a bug. 2)the second problem is how they know the security holes? consider this: if I have a password to open an isolated room in any way. how they can use shape lifting against that? the information on how to open the locked room is only yours! the real question would be: what is the protocol for the government after someone is rubbed by a morph? and forget about installing bio or non-bio identifier devices! because, without a database, they would be useless. police officers can use patterns of crimes and other investigation tools to find the morph just like serial killers. [Answer] # Morphing and perception Morphing also morphs the brain and the senses. For larger creatures and the brain this isn't a big problem, but morphing into a pigeon has serious consequences for capacity. Menory, processing, decision making and situational awareness is either diminished or radically different. But you have a heavy sci-fi vibe that might allow that I would then consider the creatures senses. As you say, the people go blind if they choose a mole. Considering that, lets look at the pigeon example. I place question marks if a pigeon eye has the focus depth and general ability to read even basic text. They are eyes meant to look all around for predators, making them highly inefficient in focusing on specifics. Considering this it's more likely that for lots of spy tasks we would use predators. Humans have a highly visual based society, so predator eyes that can focus properly are all important. This highly limits the available morphs. Other senses can still offer information, like superior smell, yet are also more niche applications. To add, you need a certain size to effectively focus/read, so fleas or jumping spiders are out. Also their hearing is probably too limited, as it's focused for their purposes and not human things like a book, conversation or monitor screen. These things highly limit the available morphs for spying. We need predators of sizes that can support the understanding of the human world. Many predators are thus unsuitable as they often avoid contact with humans. Cats or dogs would then be an easy pick, but in such a society you'll probably limit their movements, or have iron clad identifiers for them and kill any that fail a test or are just in general suspicious. Even things like eagles are limited in use. They might spy on a house or through a window, but again this might not be enough to identify text, they are more often rare and shy away from urban areas and have limited living areas. # Conclusion It'll be easy to identify morphs. They are highly limited in their choices to spy upon others thanks to perception differences. Identifying a person, text or sound can already proof impossible for many smaller creatures. Creatures that can navigate and understand the human world are limited, often rare in appearance, might not get access everywhere and are easily identified as morphs because of their unusual behaviour. [Answer] **Nanobots are used to detect if people have shape-shifting nanobots in them** Assuming many people want to defend against people abusing illegal shapeshifting means that likely the government or people selling home security would have developed nanobots that can be sent out automatically towards any living creature, such a nanobot would likely be much easier to design and make than shapeshifting nanobots so it is very much possible they made something like that. the nanobots will send a signal if they find any which triggers the alarm and registers the person, if it doesn't find anything for a certain time it will break itself down so it can be removed by the body especially a government would likely make something like that due to the average obsession with knowing everything about someone, especially if it is something many people are afraid of. in that case, they might just give everyone those bots(this might be boring in a story, so..), or have the bots remain and send out a signal so that the system will not trigger if the animal it detected already has the nanobots, this would allow for a nice plot where eventually someone figures out how to spoof that signal and pretend to have the bots while in reality not having them and only having shapeshifter bots. **if you don't care about that method you can try the following things:** You talk about nanobots, which assuming they work on something like electricity or resonance. **The nanobots resonate, block/cancel out, and or send out a specific frequency** Long ago this same principle was used to spy the white house, a small wallhanger was made then they added a microphone and a small thing which reonated to a specific frequency, they spies would send out a specific radio signal which would activate and power the device, the device would send back audio on a different frequency. real nanobots also respond to certain frequency, just like a RFID but often a higher frequency. magnetic induction or vibration can often also be used, this is used to scan the ground for things like the underground landscape, water or metals, etc. with something like this you could easily notice if someone is a shifter since they have the nanobots and probably lots of them which will be different. **This can be used in a radar-like way**, which is also actually already being done and researched right now, radio or sound waves for 3d scanning and figuring out what material something is, or what it consists of. **High voltage or strong magnetic fields** will mess up the nanobots and work kind of like a force field, the nanobots are powered by something, that same thing can be send out in extreme level to render the bots useless. the same goes for canceling it out, since they might send out signals or one might design a specific signal which causes currents in the devices going the other way. [Answer] **OPTION 1: DON'T TRACK THE MORPHS, TRACK THE HUMANS** Basically, you could make the society a paranoid totalitarian regime that keeps a truly ridiculous hold on everyone who is a citizen, routinely violating its citizens' privacy through tracking devices and/or truly obsessive amounts of cameras and recording devices. **OPTION 2: KILL ALL ANIMALS EVERYWHERE!** If you are okay with the leaders being absolute idiots with no concern for the integrity of the environment, the leadership could simply decree that all animals not wearing the patch that identifies them as a legal morph should be killed, out of concern of the fact that they may be illegal morphs. ]
[Question] [ For years, I've been building and rebuilding an alternate Earth. The point of departure is 56 million years ago, when the hottest episode in the last 100 million years, the Paleocene-Eocene Thermal Maximum, lasted four to five times longer than it did in our timeline. Here is some of the backstory that is relevant to the question at hand, with some passages highlit in bold: > > The evolutionary history of the primates, like virtually everyone > else's, is long and extremely confusing. According to the molecular > clock, the last common ancestor of all primates lived between 90 and > 63 million years ago, yet we have found no fossils dating from that > particular window. Apparently, the dry-nosed haplorhines (tarsiers, > monkeys and apes) came first, with the wet-nosed strepsirrhines > (lemurs, bushbabies and lorises) diverging from the haplorhines > between 90 and 55 million years ago. There is conjecture that > Plesiadapiformes were archaic primates, but there is doubt as to > whether modern primates actually evolved from them. **Two other groups, > Adapiformes and Omomyoidea, throw a monkey wrench at the case because > both groups appeared suddenly in the fossil record with no physical > evidence of past transitions, and they were already diverse by the > Eocene.** So were those two groups already around to witness the > Paleocene-Eocene Thermal Maximum, much less the fall of the dinosaur > empire one million decades earlier? > > > Well, whatever the case, at 1750 species, the primates ended up being > the most diverse of Great Lakes Earth's mammals, occupying the niches > filled back home not only by our primates, but also by fruit-eating > and predatory bats, sciuromorph rodents, carnivorans and even > cetaceans. > > > The two superfamilies of **carnivoran-like primates, the feliform-like > terrailuroids** and the caniform-like mixotherioids, **have been > identified as adapiform primates, which is amazing because back home, > that particular group died out during the Miocene.** > > > Here are some of those "carnivoran-like primates", all drawn from a commission by the DeviantArtist "AlienOffspring". [![enter image description here](https://i.stack.imgur.com/PxGAs.jpg)](https://i.stack.imgur.com/PxGAs.jpg) The dobarchu--an adapiform primate that looks like a cat that lives like an otter--and the dard, an adapiform primate that looks like a cat that lives like a badger. [![enter image description here](https://i.stack.imgur.com/ibPXn.png)](https://i.stack.imgur.com/ibPXn.png) The onza, a primate in a world sans *Puma*, and the pard, a primate in a world sans leopards and jaguars. [![enter image description here](https://i.stack.imgur.com/WVd5o.jpg)](https://i.stack.imgur.com/WVd5o.jpg) Two species of sphinxes, plains-running pursuit predatory primates in a world sans lions, cheetahs and scimitar-toothed cats. [![enter image description here](https://i.stack.imgur.com/rr8rf.jpg)](https://i.stack.imgur.com/rr8rf.jpg) A Bengal tiger used as a comparison for the two species of dubas, forest-exclusive primates that wrestle its prey like saber-toothed cats did in our timeline. [![enter image description here](https://i.stack.imgur.com/Rpj0K.jpg)](https://i.stack.imgur.com/Rpj0K.jpg) The lingbacker, an Arctic/Atlantic primate in a world sans rorqual whales. The criticism here is that none of them look even remotely like primates, so what changes would be needed to better sell the audience that these are, indeed, primates in an alternate Earth? [Answer] I'd recommend focusing on the traits shared by the largest subset of primates. ### Five fingers and opposable thumbs There's only three primate species without five fingers, and even their hands have four. The presence of a hand is a very recognizable primate trait. [![enter image description here](https://i.stack.imgur.com/N0vjB.png)](https://i.stack.imgur.com/N0vjB.png) ### Fingernails Likewise, almost all primates have flat nails on their fingers, rather than claws. The primates that *do* have claws, have grooming claws on their hind legs — not footpads with claws, like your pards, sphinxes, and so on. [![enter image description here](https://i.stack.imgur.com/McEXN.jpg)](https://i.stack.imgur.com/McEXN.jpg) ### Flatter faces / no snout One of the key features of primates is sacrificing smell for vision. All diurnal primates are at least dichromatic. Having a snout breaks up the 'face' dynamic that we associate with primates [![enter image description here](https://i.stack.imgur.com/il7q6.png)](https://i.stack.imgur.com/il7q6.png) ### Forward-facing round eyes Paired, forward-facing round eyes with no major obstruction. Having pupils, retinas, and sclera. Aping that will help create the primate-esque gaze. Even tarsiers, the usual exception to every rule for primates, have these [![enter image description here](https://i.stack.imgur.com/CMz6f.jpg)](https://i.stack.imgur.com/CMz6f.jpg) [Answer] **Start with a primate, then work towards your creature.** [![Start with a primate](https://i.stack.imgur.com/byjBi.jpg)](https://i.stack.imgur.com/byjBi.jpg) <https://sibyliachavonet.artstation.com/projects/DPeyG> Your creatures look a lot more like their real world nonprimate analogs than they do like primates. I take it that is your problem. I suspect your artist started with a familiar animal, then tweaked it. A solution would be to have the artist start with a primate as the model, rather than the real world analog animal. Your badger and tiger as drawn look like a badger and a tiger. You could make them more plausible primates by starting with a baboon and a gorilla. Keep hints of their provenance. Your audience will see the long nose and ruff of a baboon, see the tail and stance and understand that this thing is fundamentally a baboon. Your audience will see the distinctive humanoid musculature of the gorilla transferred on a catlike frame and understand that this is a gorilla that has gone tiger. [Answer] # Exercise your creativity Primates are rather primitive mammals; some of the Haramiyida, if encountered, might [plausibly](https://scinews.ro/euharamiyida-schimba-istoria-mamiferelor/) be thought to be primates, at least at a distance, and they likely precede mammals entirely. So there is conceptually not much problem with imagining that primates could have branched out and become cats and whales and so on, if circumstances encouraged it. After all, there's literally no telling what evolution *could* have done. Nonetheless, a neo-whale isn't going to *look* like a primate, any more than you can have your cake and eat it too. If you want a primate that lives under the water and eats plankton, you want some kind of Kurt Vonnegut solution. (I didn't find useful art; [This isn't it](https://3.bp.blogspot.com/_-fKs3szNVcU/TNSfQG8sXeI/AAAAAAAAAOc/wiDN4EYewaI/s1600/EvolutionOfMan.jpg), but *dang*...) Maybe your primate whales build some kind of combs that catch plankton, and catch it in a toothy maw that looks more like a mutant vampire horror. Perhaps they use prehensile tails to latch onto whale sharks and force them to do the swimming. Maybe the sphinxes are more like chimpanzees in how they prey on and tear apart other primates; maybe they can navigate the forest canopy whenever it suits them. To make primate-*looking* creatures, you need new life histories different from those best suited to existing non-primates. ]
[Question] [ [This logbook entry from Destiny 2](https://www.destinypedia.com/Mysterious_Logbook#-046-) states that > > WARNING. Novel prion detected in body collagen. Hypothesis: Jovian > magnetosphere promotes highly abnormal protein folding. Prognosis: > massive sloughing/fraying of basement membranes, Loss of tissue > binding, inhibited durotaxis of new cells, delamination of all body > tissues into thin sheets. You will fall apart Like an old book. > > > In other words, Jupiter's magnetic field is causing the body to misfold proteins, resulting in what sounds like an even-nastier-than-normal [prion disease](https://en.wikipedia.org/wiki/Prion) - in other words, a misfolded protein that turns other proteins into misfolded proteins. Imagine a zombie apocalypse, but with the building blocks of your body. While I'm unsure as to whether Jupiter's magnetic field is strong enough to do something like this, I am interested in the concept. **Is it possible for a magnetic field to cause proteins to misfold in a way that makes those misfolded proteins capable of misfolding other proteins?** [Answer] YT [How Much Power Does Magneto Need to Rip Iron from Blood?](https://youtu.be/htaYu2NGOgw?t=204) - pretty entertaining to watch without sacrificing science Fun fact, mentioned in the clip, moving inside the [7T field of a RMI makes you taste metal](https://onlinelibrary.wiley.com/doi/10.1002/jmri.21153) (by creating currents in your body strong enough to excite the nerves). Remember kids, if you ever wake up inside an MRI machine that you don't want to be in, moooove awaaaaay sloooowly! "Human blood and human tissues is in the $-10^{-6}$ to $10^{-6}$ magnetic susceptibility" - that is, ignorable weak. So weak that, before any effects of the magnetic field start to manifest on the protein (and their folding), you will get intensities of the magnetic field that will make the actual chemistry of the elements in your body impossible (by modifying the shape and the energy of the electron shells) [Answer] Probably it won't do harm.. at least not very quickly.. a few years ago some mad scientist won the IG Nobel for physics with levitation experiments in a magnetic field. The field applied was a lot stronger than Jupiter's, which is about [470 micro tesla](https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter) at the equator. It took 16 Tesla's (!) to lift a *live* frog.. it survived the experiment, [![enter image description here](https://i.stack.imgur.com/Vt8TG.png)](https://i.stack.imgur.com/Vt8TG.png) <https://slate.com/business/2014/05/nobel-prize-in-physics-andre-geim-went-from-levitating-frogs-to-sciences-highest-honor.html> <https://www.science.org/content/article/floating-frogs> [Answer] Unfolding a protein it's pretty easy: a change to the environmental condition of that protein can do it, be the change temperature, pH, water concentration, etc. Unfolding a protein in way that it keeps it active and even capable of transmitting that unfolding to other similar proteins is a completely different game. Since we have prions we know it can happen, but since we don't have as many prions as we have viruses (to the best of our knowledge) it's safe to conclude it is something very rare. Therefore I doubt a random strong magnetic field can result in the right modification in the right place to achieve this result. ]
[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 has got to be the strangest question I've ever asked. I was looking at lab grown meat and thought - I've never grown these cells in a lab - but I sure have grown bacteria! Currently though, this meat is still quite expensive. This surprised me, since bacteria grow in petri dishes so happily. I was wondering, could I make a burger patty out of bacteria? I would grow them in a petri dish and then fry them. Then I would build a burger. My question is: 1. Is it feasible economically to grow this much bacteria? (how much would a patty cost?) 2. Are bacteria nutritious? 3. What would it taste like? I would prefer a very hard science answer. [Answer] # Yes. [A researchgate article about using bacteria (in the form of microbial mats) for food](https://www.researchgate.net/publication/332173095_Making_the_case_for_edible_microorganisms_as_an_integral_part_of_a_more_sustainable_and_resilient_food_production_system) Best of all is, you don't even have to form them into patties yourself, the microbial mats will do the self-organization for you! [Here is another example of some Finnish scientists making a tofu-like substance from bacteria.](https://www.smithsonianmag.com/innovation/making-food-electricity-180964474/) [Wiki link for Microbial Mats](https://en.wikipedia.org/wiki/Microbial_mat) Sorry for making this a mostly links-only answer, but I am very far from an expert in the field itself, and adding the usual visual images would ruin your appetite from,.... well, for *days* [Answer] Consider it as an addendum for PcMan answer, mostly on economic feasibility. At uni, we did grow E. Coli and in the context of the question, it can be said we had a funny substrate for their happy growth. The substrate was meat soup(sort of, how it was made), we even joked about tasting it, but yeah didn't happen, the thing was like 20 y.o. stuff in the bottles, color like soy sauce. We diluted it, added salt, and used it to grow night cultures(concentrations of bacterias like 1e8/cm3, or something, forgot it), made agar with it for Petri dishes. In that sense economical feasibility, if you rob an old soviet lab for this magical stuff it can be economically feasible, even if you are better off with just drinking it. But otherwise, it depends on different factors. The efficiency of a process, they do not eat all of it because of their own byproducts, other strains of different stuff start to catch up with those in a few days later and all that. So for a full conversion of your substrate, you lose energy anyway in such conversion, but additionally, for that, you have other means on top to keep your tasty strain of bacterias to be a predominant inhabitant of a substrate, and you have to remove their byproducts (a result of metabolism) for them to enjoy it further. Removing byproducts and keeping culture to stay monoculture is an effort in the first place, but how big these efforts are - it differs depending on what is grown and how it is grown. In that sense bacterial mats(SCOBY) like the kombucha thing it super easy - one removes byproducts by drinking it and replenishes it with tea and sugar. Sometimes it can get infected, just peal layer off, cut off that piece and you are done. If one keeps cleanliness while operation on a level of "wash your hands", do not touch the thing - it enough to not have such problems at all. Keeping E. coli to be a single strand is also relatively simple, just your regular lab procedures seed it to get a colony, grow that colony. Or like that [E. coli long-term evolution experiment](https://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment) on their site they have their working procedure but basically, it is done by having backup copies in a freezer and detecting contamination. * but with a petri dish, you know once you open it the next day, remove the lid, it will go bad in few days(3-4-5) due to mold or something strange. Even if you do not open it it will take longer but it will happen. To prevent reduce chances it needs a cleanroom environment, we had regular ones cuz operation procedures are less expensive and we didn't need those for what we did in the way we did. But that meat growth may require more strict conditions. With yeast it is also easy to remove byproducts, also in line with a drink-it behavior, you know, and that higher C2H5OH is their protective mechanism to keep themselves the only consumers of the substrate. (if they are in the anaerobic mode, for mass aerobic mode is preferable, more mass of result product, but things may or may not become a bit harder) All those more or less are liquid states, cultures have some tricks this or another way because they are alpha predators on that microbiological level, more or less. But grow meat and recreate texture at the same time protecting it from spoiling, because any bacteria or mold wants to corrupt eat it as well, so as its substrate - it is a situation similar to sheep against wolves - that can be a challenge. Mammal bodies can do that because of the immune system and skin and few other tricks. Challenge looks like 10x compared to a regular lab situation and culture. * and here I would like to be more specific, but I do not know what they do to grow meat things. So your efforts go up as well, decreasing the economic feasibility. ## energy, nutritional value 13.91 MJ/kg energy value for dry yeast, and conversion ratio plant matter and such to yeast is like around 28%, as I see from nonenglish sources, not super credible as well, for English references it may be useful to look up "Yeast cow feed" or something, it used as making supplementary feed for cows and such. Dry meat nutrition value is about the same <https://www.eatthismuch.com/food/nutrition/dry-meat,2118470/> So if you have similar water content as the nutritional situation it can be 1:1, which is somewhat expected. So in a sense of energy, substrate conversion can be around 30%, and if we take sugar as a price gauge for a substrate which is 1/10 of meat price then as result it is possible to have endproduct of 0.3 prices of meat. One needs macro and microelements to grow stuff, not a big deal, look aquaponics prices for that, not expensive stuff. So the question of economic feasibility lays in - is it possible to squeeze the procedures in below that 0.7 leftover prices, for the strain of a culture you need for the purpose. And it heavily depends on that culture and procedures it requires. For some random cultures, it can be easy, with others it clearly can be expensive on a lab scale. As for industrial-scale, there is some potential, but it heavily depends on specifics. 1. It depends on what you are ready to eat, but yes it can be cheaper. Try worms btw, the red worms especially. Paper(cardboard) and leaves are what they need. 2. Yes, it is just a biological matter, it can have different digestive values due to different factors, but we are made of pretty much the same stuff energy-wise. Autolysis can be your friend in some cases, for yeast as an example. 3. It depends on what it is. (Here should be a screenshot from soy sauce factory, their fermenting barrels, and a guy tasting it happily(kinda, he is japan, he had strange tasting/thinking face), without any explanation to it, but ... - yeah definitely meme material from the future). [Answer] You can with current non-research levels of technology. We already have recipes that call for yeast (in quantities beyond just adding texture to bread). See lactation cookie recipes, e.g., <https://www.howsweeteats.com/2015/02/lactation-cookies/> . You can purchase bacteria in the same way you can purchase packets of yeast: <https://pondperfections.com/product/orb-3-bacteria-packet/> . To go from cookies to patties, you'll need a recipe with more bacteria and more binders, perhaps eggs, gum arabic, or emulate hardtack. Ask cooking SE. ]
[Question] [ **Frozen/Solid light Shields** I can't find much online; but after listening to an Isaac Arthur episode where he briefly mentions frozen light, I immediately thought about the Hardlight items from the Halo series. My basic idea: being able to control the light and the distance it can travel so that it becomes frozen in place a certain distance from the emitter. So a ship would have hundreds or thousands of these shield projectors to create overlapping coverage of the ship. Now I am thinking, since this might require lots of energy, that the shields will be an active defence and only turn on when a sensor picks up an incoming attack. From a scientific point of view, **would these shields be able to stop any physical matter, of would they only be useful against laser attacks?** (If even useful against those at all). The shields would experience fatigue then and need to cool down after prolonged use. This would give the *Star Trek effect* of "forward shields at 40%". Except instead of diverting power to the shields to increase their duration it would be diverting cooling to the shields since the ships will have limited cooling abilities. Does this seem feasible or am I way off the ball on this? I guess is this technology into feasible as information and communication devices or can it have physical applications. Essentially, I want to neutralize laser weapons on warships and have a space navy that relies on physical kinetic and explosive weapons. [Answer] ## Light can be trapped, slowed or reflected in a medium, but not frozen in a vacuum except by gravity Light is essentially an oscillation in the Electro-Magnetic field. The wave nature of the light propagates through space (a vacuum) at speed. The smallest quantity of light is called a photon - these are massless and move at 'the speed of light', or more accurately, the 'speed of causality'. Light can be slowed to a standstill in a medium, as in [this article](https://www.sciencedaily.com/releases/2013/08/130806111151.htm). Even simple water will slow light - being caused by interference with electrons. Trapping the light in a crystal is possible, at least for a moment, by having light constantly interacting with electrons in the crystal in precise conditions. These precise conditions however are easy to deteriorate, so the light eventually will start moving again. The only way I could think of to 'freeze' light in a vacuum is to bend space, through General Relativity. Currently the only way to achieve this is to use a black hole, where light emitted by an object at the event horizon will remain stationary. For your shield, perhaps space could be warped, or gravitons discovered (we haven't discovered this yet) that allow you to 'freeze' light in space, if we can manipulate it. You have inadvertently discovered the gap we have in our knowledge at the moment, between that of General Relativity and Quantum Field Theory. BTW: Keep in mind that light travels at the speed of causality - so the light beam experiences no 'time'. So you could accurately say that every light beam is indeed 'frozen' from the point of view of its own frame of reference. This revelation was what made Einstein conceive of the Theory of Special Relativity. [Answer] As 'light' refers usually to 'for humans visible light' I will focus my answer at this. And my answer is: that will get difficult. Visible light, defined as photons and waves, has nearly no impact on physical matter, as described on [Wikipedia](https://en.m.wikipedia.org/wiki/Light) like this: > > Light exerts physical pressure on objects in its path, a phenomenon which can be deduced by Maxwell's equations, but can be more easily explained by the particle nature of light: photons strike and transfer their momentum. Light pressure is equal to the power of the light beam divided by c, the speed of light. Due to the magnitude of c, the effect of light pressure is negligible for everyday objects. For example, a one-milliwatt laser pointer exerts a force of about 3.3 piconewtons on the object being illuminated; thus, one could lift a U.S. penny with laser pointers, but doing so would require about 30 billion 1-mW laser pointers. > > > There is the idea to use light pressure for engines of spaceships in form of solar sails, but the energy-source for this pressure is a whole sun, you will not reach this energy level with engines that easy (if you do, you would at least have a starting point for your technology). As light does not block itself you will not be able to use light against a laser I think. [Answer] @flox gave an excellent answer; explaining the quantum nature of light (technically described by a massless boson which is the carrier for the electromagnetic force). For further discussion of the non-local nature of light in the absence of an electromagnetic potential see my answer and comments [here](https://worldbuilding.stackexchange.com/questions/174438/science-of-green-lantern-and-solid-light-constructs/174440#174440). Quantum electrodynamics, the field which describes the electromagnetic interaction from a quantum (non-classical) viewpoint, is so accurate that it has been called "jewel of physics". This is to say that the way that light and the electromagnetic force interact is very well understood and the theory does not allow for electromagnetic radiation itself to produce bound, localized states in the absence of media (mass-carrying particles). @AlexP has a comment which highlights the difference in terminology and theory very well, while the electromagnetic interaction hasn't changed, there are new discoveries regarding the phenomena the interaction produces; semantics and journalistic sensationalism playing a large role here. **From a scientific point of view, would these shields be able to stop any physical matter, of would they only be useful against laser attacks?** Even in Halo, the "energy shields" are described as an electromagnetic field effect, since the field shown contain closed loops, it is not consistent with free-space electromagnetic waves. Thus from a fundamental scientific point of view, you would need the electromagnetic waves to be confined to a medium to produce the desired effects, what the medium is and the phenomena produced by the interaction however, is up to you and can always be described with hand-wavy physics without breaking fundamental laws. [Answer] --- ## It might work very well as a Whipple Shield. --- **Assumptions**: We will assume that some new physics is discovered that allows light to be frozen in place with a relative velocity of zero, in complete violation of known laws. This "wall of light" would be invisible (you can't see light until it hits you in the eye), unless you introduced the extra rule that this "stationary light" is not entirely stable and decays into ordinary propegating light waves over time: in this case your shield will glow exactly as we might want to make it look awesome. --- When the projectile (lets say a missile or a bullet) hits your wall of light the light will not stop it at all, light exerts next to no pressue on objects. However, some of the light will be absorbed, so it will heat up the missile/projectile. Heating up an inbound projectile is actually a very standard way of protecting against tiny meteors (bullet sized) in space. When the projectile heats up it will evaporate into a ball of gas. Being hit by a beach-ball sized blob of warm gas is like being burped at, it is much, much less dangerous that being hit by a hard little rock or a bullet. Traditionally their is a thing called a "Whipple Shield" : a thin layer of metal (maybe a bit thicker than tinfoil) that makes the bullet/meteor evaporate into gas, then you have a gap to give this gas blob time to spread out. <https://en.wikipedia.org/wiki/Whipple_shield> So your shield could be used the same way. You light-wall might have some advantages compared to the metal ones. It might be less heavy (although you would need some kind of generator to power yours), it might be adaptive: so you can change the distance you project the light-wall ahead of you in response to the speed/composition and size of the enemy's projectiles. --- Whether or not the thing works against laser weapons is entirely up to you as a world-builder and known physics has no prejudice against either choice. You could say it does work, because whatever thing you have that holds light in place stops the new light, or you could say it doesn't because it doesn't. --- Suggestion for the "physics". Just don't say anything. The entire thing is outside known physics, which is *completely fine*. Its the future. If someone told people in the 18th Century about the power of nuclear weapons they would complain that no chemical could possibly be that explosive. The same could happen again. ]
[Question] [ In a battle, a mage uses a spell that summons a bolt of lightning from the heavens to strike whatever the mage desires. The lightning lands smack dab in the middle of a tightly packed formation of men, similar to a phalanx. What happens? -How many people would die of this? -How many would be injured? In its current iteration, the main effect this magic has on the battle is not the direct damage, but the disorientation caused by the light and sound of a lightning strike, which leaves the formation vulnerable, which is another valuable follow-up question to ask: How long are the soldiers blinded by this lightning, assuming they looked right into it, and how long would it take for their hearing to recover? Edit: For the purposes of this question, the men in the formation will be wearing chainmail hauberks over gambesons, and conical steel helmets. They will have kite shields, and arming swords. Their footwear will generally consist of simple shoes/boots of various materials, with the richer soldiers who can afford it wearing iron greaves (though these soldiers are in the minority) [Answer] If your magician can summon a real lightning strike that you normally only find in a thunderstorm, then the effects are profound. ### Range Such a strike has millions of volts. It can kill anybody within a few meters of distance, and severely hurt and throw off their feet anybody within tens of meters distance. The closer you are to the center, the more severe the effects. There was a lightning during a soccer game. The lightning hit the ground not a man, but all players were thrown to ground and unable to play afterwards. ### Medieval Armor Chainmail might not protect so much as most of the victims will have the strike entering by one foot and exiting by the other while the charge disperses over the ground. Again, it's not the flashy effect, it's the electricity. The farer away you have your feet from each other, the heavier the consequences for you. ### The Shock After you have been tasered, you don't get up easily and you can have after effects for hours. Those poor warriors will have the same. So if it happens during battle, the opposing army will have an easy day. This will be the main effect for most of the victims - those who are up to some two or three dozen metres away. ### The film effect The one person in the center who is hit directly, if his helmet is made of steel, might have a molten cap afterwards. This is deadly for sure - steel is a bad conductur, so it heats a lot, melts, drips liquid steel. Induction Cookers work because steel gets incredible hot when forced to conduct. Worse, it also doesn't make a faraday cage if there is no connection between the steel parts, or rather, the connection is provided by the person inside the steel parts; accounting for cooked and burned-out parts of the body after the strike. ### Formations If people are in a dense formation like a shield wall or phalanx, they are even touching each other. This would make everything worse, for both they have no distance to the impact and the entire formation might even provide a better conductor than the wet ground. If your magician can direct a lightning strike into the middle of such a formation and he hits someone, the entire formation goes down, and deaths could go up into the hundreds. Even when they are not touching skin to skin, being so close to the Center of the strike will render the men severely hurt and at least unable to fight. [Answer] In the modern day, chain mail is used to protect people from electrical currents. High voltage electrical workers may wear chain mail, and there's a [video of a man being struck by artificial lightning while wearing chain mail](https://www.youtube.com/watch?v=QqEesFaboV4). Even over long periods of time, the man does not seem to be injured, and the chain mail does not seem to be appreciably heated. With plate armor, the conductive surfaces are larger, and thus tend to be more conductive. Furthermore, there are less jumps between armored portions that could cause problems. Gaps between armor is something that is designed against, even in the relevant time period. Any gaps are holes that an enemy can wedge open with a sword. Furthermore, people wear leather between metal armor and their skin, which is an additional layer of insulation. According to Wikipedia, steel structures can function as part of lightning rods. Lightning will preferentially flow through the armor, and where it is unable to, might flow through the leather. It is extremely unlikely it will flow completely through the leather, into the body, and then back out through the leather. Steel is a relatively good protection against lightning. For instance, it is recommended to shelter inside, for example, a car during a lightning storm. Lightning does not cause the car's body to melt, and it is even less likely to melt the less resistive (because of the higher cross-section area) steel armor. If they are touching each other, the resistivity will further decrease, thus reducing the effect of lightning. The thunder is around 120 decibels, equivalent to standing at the front of a rock concert for less than a second. Deafening is possible, but unlikely. Lightning is brighter than the sun, but only for a few milliseconds. This may be enough to temporarily blind someone looking at it (and it is certain to blind someone should the lightning strike directly in the eye). However, there seems to be a dearth of information on the typical brightness of a natural lightning strike, so it is difficult to determine how long a person may be blinded. However, lack of eyesight is likely to occur for at least an eighth of a second (blink time), and it is more likely for temporary blindness to occur should the lightning strike at night – though it is essential to note that the troops will likely be more scattered at night. In summary, lightning will likely be more effective as a psychological weapon or as a tool to frighten horses than as a direct damage-dealer. Injuries from electricity and secondary heating effects are likely to be minimal to none, injuries from sound are possible but short-lived, and injuries from light are likely, but hard to quantify. [Answer] Clearly the lightning most likely kills the individual it strikes. It may kill others in the immediate area. There are a few cases in real life of multiple individuals being killed by one strike, and more with groups of animals. There's a video online of 23 cows lying against the same fence being killed by a strike. A lot depends on the exact geometry of what happens, but if there is physical contact between people with reasonable conductance, you could see a lot of casualties. If they are insulated though, or not actually in contact (and they might not be in a phalanx with proper spacing) it may only go through one person. Flashblindness would last a few minutes at most but probably would not be a major effect. In daytime the flash effect would probably be minor -- it's very hard to dazzle people on a sunny day without light sources powerful enough to cause damage. And this would only affect those looking the wrong way (helmets and visors may provide accidental protection). 'Close thunder' - the supersonic shockwave before it decays to acoustic speed and becomes thunders - would blow out the eardrums of anyone within a few metres producing deafness lasting several days at least. The EM pulse form the lightning may also kill unlucky individuals nearby with cardiac arrest but this is rare. Coincidentally enough, I just wrote this piece about the catastrophic effect of lighting on the English Army in 1360 -- <https://www.theguardian.com/news/2020/apr/17/weatherwatch-deadly-storm-king-edward-english-french-troops> ]
[Question] [ In many fantasy worlds, dragons are depicted with six limbs: four "legs" (two front limbs and two hind limbs) and two wings. In the real world, we don't really see vertebrates with more than four limbs, but would it be feasible for six to develop? If so, how would this happen? [Answer] ### A parallel clade to the vertebrates we know In our world, all land vertebrates evolved from a four-limbed, lobe-finned fish, and so all vertebrates have four limbs. Growing a new pair of limbs is hard, but losing an existing pair is not so hard. In your world, vertebrates evolved from a *six* limbed fish instead - and then one group of those early six-legged lizards lost one pair of limbs, evolving into vertebrates much like those we know. However, a completely different group retained the six limbs, and those diversified into a number of different groups of six-limbed vertebrates - including dragons, griffins, gargoyles, pixies, pegasi, centaurs, and other species that we don't have names for. Some might resemble species that exist in our world, but this is only a result of convergent evolution; they are not actually related at all. If you want a world where dragons are the only six-limbed species left, perhaps they are a "living fossil" clade, the sole surviving representative of a mostly extinct group. Our world has plenty of those. [Answer] Off the top of my head, there are two ways to go about this: **Avatar: The Last Airbender**: One of my favorite things about ATLA is it is subtly alien to us. Sure, humans are basically the same as we are now but with superpowers, but the animals are very different. Animals such as but not limited to penguins and sky-bison have six-limbs despite resembling vertebrates. So, in a world were vertebrates do have 6 limbs, dragons having this isn't much of a reach. [Dragons do exist in the ATLA universe](https://dragons.fandom.com/wiki/Dragon_(Avatar)), and have 4 short legs and 2 wings, with bodies like Chinese dragons and wings like European dragons. **Dragons are insectoids!**: Dragons as we know them are lizard-like creatures, divine, breathing fire, wise, etc. What if they weren't that at all? The only six-limbed, winged creatures we know about are bees and other bugs, and we know that in the dawn of insects millions of years ago we had [giant flying dragonflies](https://en.wikipedia.org/wiki/Meganeura) and more. So perhaps the dragons you are referring to are descendents of such creatures who also developed chemical reactions that allow them to spit highly-flammable substances. This would also change the way dragons work in your universe entirely, as depending on what kind of insect you want to base these creatures on, you'd have 2 further options. **1) Base them on dragonflies**, so these creatures are massive, dangerous monster-bugs, and not very smart. Ironically, their exoskeleton may or may not be entirely immune to fire either. **2) Base them on bees**, so although each one of these creatures isn't too smart, their hive as a whole acts as a single unit, controlled by a queen (much like the [Formics from the *Enders Game* books] but dumber[3](https://enderverse.fandom.com/wiki/Formics)). I hope this helps! [Answer] **Wings have developed from dorsal fins or plates** Some dinosaurs had impressive dorsal fins, like the [spinosaurus](https://en.wikipedia.org/wiki/Spinosaurus), or dorsal plates, like the [stegosaurus](https://en.wikipedia.org/wiki/Stegosaurus). The latter had a double row of dorsal plates (see picture), with plates alternately on the left and right sides of the spine. It might not be possible for symmetrical pairs to develop, but two slightly offset wings could probably provide anough stability, especially if aided by smaller dorsal fins along the entire length of the back. Basically, imagine a slimmer stegosaurus where two of the dorsal plates have developed into huge fins. It would be no stranger than, say, a mammal whose nose had developed into a several meters long, very strong prehensile tentacle - but that is surely too strange to imagine. :-) [![enter image description here](https://i.stack.imgur.com/mBwWt.jpg)](https://i.stack.imgur.com/mBwWt.jpg) ]
[Question] [ This would be something mass produced by a secret organization that has learned how to mass produce antimatter. Since antimatter particles colliding with the particles of its corresponding regular matter form results in them both annihilating, is it possible that shooting antimatter at someone would just vaporize them? As well as most other materials struck? And if so, is there a way to fire antimatter through the air without it annihilating as soon as it touches the air? Basically, the end results would be energy cannons that are handheld rifles, guns on tanks and planes, and starships too, that fire orange beams that are composed of a mixture of most types of antimatter so they'd annihilate anything they hit except for what the air is composed of. A good comparison of functionality are the Tesseract-powered guns from *Captain America: The First Avenger*. If I wanted a series of guns that function in that way but are more powerful, would antimatter be able to accomplish that? [Answer] **Antimatter particles would have limited destructive power, because of the Leidenfrost effect.** I had not thought of the Leidenfrost effect in this context but it makes good sense and is very cool. First: the Leidenfrost effect. <https://helix.northwestern.edu/blog/2015/02/stovetop-science-exploring-leidenfrost-effect>[![leidenfronst effect](https://i.stack.imgur.com/KqZwu.jpg)](https://i.stack.imgur.com/KqZwu.jpg) <https://en.wikipedia.org/wiki/Leidenfrost_effect> > > The Leidenfrost effect is a physical phenomenon in which a liquid, > close to a surface that is significantly hotter than the liquid's > boiling point, produces an insulating vapor layer that keeps the > liquid from boiling rapidly. Because of this 'repulsive force', a > droplet hovers over the surface rather than making physical contact > with the hot surface. > > > [Backyard scientist really brings this home with his video of pouring molten alumimum on a steak](https://www.youtube.com/watch?v=hPwc2fDhuM4). One would think that with such heat energy as is in the molten aluminum, the steak would burst into flames, or at least be cooked. But the steak stays raw - at the interaction between metal and meat, the products of that interaction prohibit a greater interaction, and so the metal slides off the steak of a cushion of steam. Exactly this would happen with your antimatter projectile. [Matter-antimatter Cosmology: the Radiative period](http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1973A%26A....28..253A&defaultprint=YES&filetype=.pdf) > > When annihilating, nucleons and antinucleons produce a relatively > large number of high energy photons, positrons and electrons. These > particles, and having a small or zero mass, carry a large momentum. As > a result they exert a strong annihilation pressure (also called > Leidenfrost pressure) upon matter and antimatter brother energy also > heats the medium… Because of the short annihilation mean free path, > matter and antimatter penetrate each other only in the region along > the boundary with the depth small compared to the emulsion typical > size. > > > When matter and antimatter come into first contact - the atoms on the outermost edge - those atoms change into energy. As a result there is an absolutely enormous radiation pressure suddenly between antimatter and matter. It pushes them apart and also probably turns some of the adjoining unreacted particles and antiparticles into plasma. The hot plasma expands, also pushing the two surfaces apart. The result: your antimatter projectile would produce a flash of light and bounce energetically away from whatever it hit, in large part intact. You might be distracted by the extremely bright, continuing and even more energetic matter and antimatter plasma clouds in the area where your projectile hit. These expand rapidly and react with each other, producing a spectacular light show. You should not be distracted because the large remaining portion of your antimatter projectile has bounced energetically away from your target and is coming back in your direction. Although even if it hits you, it will probably not hurt you that badly either. --- I should clarify - I was thinking strictly of space and an antimatter particle fired thru a vacuum. In an atmosphere the antimatter will react with atmosphere and produce a plasma cloud which will produce an even larger but less hot cloud of gas. --- Addendum 2 - More on Leidenfrost pressure which is probably a bad name. It should be called annihilation pressure. I was worried Starfish (see comments) was right. Horrors! But I am reassured. Annihilation pressure is caused by the products of annihilation. Described here: [Gamma Ray Asgtrophysics](https://books.google.com/books?id=QzYCAAAAIAAJ&pg=PA337&lpg=PA337&dq=%22annihilation+pressure%22&source=bl&ots=6JwLKx3ssu&sig=ACfU3U26amkzrVXdY9tF-awWzn3nh-WURA&hl=en&sa=X&ved=2ahUKEwjSrvPe5vvnAhUHn-AKHZnnCvIQ6AEwCHoECAoQAQ#v=onepage&q=%22annihilation%20pressure%22&f=false) > > The basic idea of the model is the following. Along the > matter-antimatter boundary, annihilation produces high energy > particles: photons, electrons, and positrons. These particles together > with secondary particles percent put into motion by collisions, carry > their momentum to the fluid which is made of matter (or antimatter)and > radiation over some distance gamma. Because as many particles > generated by annihilation are going towards my has’s are going towards > antimatter depression nature on both sides of the boundary is > inversely proportional to the area of the effective surface where > there stopped. These areas are proportional to [formula describing > boundary shape] where pa is the annihilation pressure carried by the > high energy particles. > > > [Answer] TL;DR: this is a dangerous and wasteful way to make a gun. Probably not worth it, as almost any other kind of weapon will be better. --- > > is it possible that shooting antimatter at someone would just vaporize them? > > > Well, yes. They may indeed be vapourised. The problem is that the "vapour" that results will be a cloud of very hot, very dense plasma, which will expand rapidly until it reaches equilibrium with the surrounding atmosphere. Also commonly known as an *explosion*. Delivering enough energy to vapourise a human body will create a very *large* explosion. Whilst some people are of the opinion that there's no such thing as overkill, there is such a thing as efficiency... you can kill a person, or disable a vehicle, by poking a hole through it, which requires a lot less power than reducing them to plasma and causes a lot less collateral damage. Speaking of collateral damage, the ultimate end result of annihilation is the production of a lot of gamma rays. These have a short free path in meat and metal, but can travel quite a long way in air. They're a serious risk to bystanders and indeed the wielder of an antimatter gun who is stupid enough to use it at short range. The annihilation flash will also be extremely, blindingly bright. (also note that if you shoot enough antimatter, everyone and everything will be annihilated... effective yield is 43 kilotonnes of TNT equivalent per gram of antimatter. Use sparingly) > > And if so, is there a way to fire antimatter through the air without it annihilating as soon as it touches the air? > > > You need to confine it in something... electromagnetic confinement in a [Penning trap](https://en.wikipedia.org/wiki/Penning_trap) is what people try and do currently. You might be able to miniaturise the traps so that they're merely grenade or bullet sized in stead of bomb or vehicle sized. Other people have handwaved antiparticle confinement inside fullerene molecules... if this involved some kind of confinement *other* than electrostatic then it *might* work, but I can't find any serious analysis of this sort of thing so it probably won't work. Remember that if your antimatter becomes deconfined *before* it hits the target, you'll end up having a *really* bad day. If your confinement systems run out of power, or they're badly damaged, or burnt, they'll go boom. If you're subject to highly penetrating radiation, that *could* give some of your antimatter enough energy to escape confinement which might then damage it enough to deconfine the rest, too. If people are throwing around antimatter weapons, then there will be a lot of gamma rays flying around, and these are indeed highly penetrating radiation. > > Basically, the end results would be energy cannons... that fire orange beams that are composed of a mixture of most types of antimatter so they'd annihilate anything they hit except for what the air is composed of. > > > No orange beams for you, sadly. In an atmosphere, you wouldn't be able to make a pure enough vacuum over a long enough distance and maintain it for sufficient time to throw antiparticles down the middle of the beam to zap the target, and if you *could* you could use the beam-generation system as a weapon all by itself without all that dangerous mucking about with antimatter. In a vacuum you *could* fire an antiparticle beam, but particle beams suffer from thermal blooming that strongly limit their range compared to pretty much any other weapon system. You can increase particle speed to improve range, but once you get over beam energies of about 1 GeV per nucleon you may as well just use regular matter instead (because the kinetic energy of the particle starts significantly exceeding the energy released by its annihilation). You'd be better off putting your antimatter in a missile warhead or cannon round, or using it in your own generators or rocket engines. --- Do note that there's a common canard that if you bash a blob of antimatter and a blob of matter together, they'll just blast themselves apart. This is somewhat unlikely: annihilation releases a spray of highly energetic and fairly penetrating radiation. Both blobs will be thoroughly toasted by this radiation to quite a depth, and that means they'll explode from the *inside*, not just at the contact point. You'll get two more-or-less spherically expanding clouds of plasma which will interpenetrate and annihilate as they expand. A small quantity of antimatter *may* escape in a vacuum, from the back face of the antimatter blob. There's no danger of getting hemispherically expanding clouds that won't contact; physics doesn't work that way. You can of course trivially fix this by having the mass of the confinement and delivery system exceed the mass of the antimatter warhead, and having a decent amount of that mass being *behind* the warhead. For really big lumps of antimatter, break them down into smaller, separate confinement devices. There's little danger any antiparticles will escape. [Answer] Nope. Antimatter annihilation is [265](https://physics.stackexchange.com/questions/72926/in-nuclear-fusion-reaction-what-is-the-percentage-of-mass-converted-to-energy) times more efficient than a Fusion reaction. An antimatter bullet or beam is like an H-bomb. The energy released will blow your target to bits like a regular explosive as soon as a tiny amount of matter/antimatter annihilation occurs - so you won't get the disintegration effect like you want. You could use bio/nano tech to rapidly disassemble organic matter. Have the nanites be chemically powered (or any power source that can scale down), they get hot, chop everything to bits super fast on a tiny scale, then run out of gas and die after about a persons worth of disassembly. The heat released from the rapid movement causes the person to vaporize instead of just melting into a puddle of goo. [Answer] As you say, antimatter interact with matter leading to reciprocal annihilation. Because of this you have to look at all the possible interactions between your bullet and the environment. First of all, in a traditional gun the bullet interact with the barrel by friction: this would result in a nice gamma ray burst as soon as you fire. Not a good idea if you want to destroy your target and survive. While you can think of some sort of magnetically suspended barrel to prevent the above, you cannot do much when it comes with the interaction with air, unless you ask your target to pretty please hold a vacuum tube going from your gun to him. So, all in all, antimatter guns might be feasible only in space. Unless you can come up wit an exceptionally good confinement system, allowing you to contain a few grams of antimatter inside a conventional bullet. Once the bullet destroys on impact, the antimatter will annihilate. (thanks at Demigan for the hint) [Answer] So, oddly enough, I had a similar idea to this a while back. Now keep in mind, my version is more WMD than “personal weapon,” but you may be able to scale it down. So, generally speaking, if your civilization can make antimatter in large enough quantities to weaponize, you probably have excellent containment that’s way beyond anything we have. Going on this assumption the weapon works fairly simply. It takes an antimatter “slug” and puts it in a stable magnetic field. We have quite a bit of research going on right now with plasmas generating their own magnetic fields that can serve to contain them, so this shouldn’t be too far fetched. The weapon then uses railgun or coil-gun action to accelerate the slug at *Ridiculous Speed* (Insert dramatic echo). Now, this last part may require a little more handwavium but I don’t think it’s complete sci-fi. As the slug leaves the weapon it is enveloped in a dense, cold plasma that is held in place by the magnetic field, which also keeps it from contacting the antimatter. Basically, it forms a bubble that is held in place by the magnetic field. Whenever the slug strikes a target, the bubble “pops” and then everything within a very large radius **goes away.** This also has the added bonus of allowing some penetration into a target before the bubble bursts, depending on the density of the surrounding plasma, the speed of the slug, and the strength of the magnetic field. --- A couple important things to remember: This is a pretty far future type weapon, all the stuff that I mentioned might be possible *in theory,* but we don’t have anything close to this right now. Also, antimatter is **volatile,** seriously. An antimatter hand grenade would make a nuke look like a particularly energetic firecracker. Remember, always use appropriate amounts of antimatter, the life you save may be your own. [Answer] I don’t think it’s realistic to use antimatter munitions against other soldiers, if only because it’s complete overkill. The energy released upon impact is comparable to that of many atomic bombs, I would think. (I’m thinking of Death’s End by Liu Cixin, in which a group of renegade soldiers threatens to take on an armada of space ships with little more than some old fashioned rifles and bullets loaded with antimatter.) I’m also reminded of the “lasguns” in Dune which, upon striking a shield generator, result in an atomic blast that kills both the attacker and the defender. Herbert never mentioned antimatter, but maybe his invention is closer to what you’re imagining, and the sheer power of such weapons makes for an interesting plot device. [Answer] > > If I wanted a series of guns that function in that way but are more powerful, would antimatter be able to accomplish that? > > > Yes. Assuming you can contain the antimatter inside a projectile that shatters on impact. The trick is to use very small quantities of antimatter - which is rather lucky, considering the difficulty of obtaining and containing anti-matter. E.g. half a nanogram of antimatter annihilates another half a nanogram of matter, the result is `mc^2` = 1e-12kg\*(3e8)^2 = 90000J. Mostly as hard gamma, but enough of it will result in very energetic particles (e.g. nucleons as fragments of a nucleus incompletely annihilated ). If 5% of this energy is adsorbed by the penetrated body, that's the equivalent of discharging a [12-gauge shotgun](http://wredlich.com/ny/wp-content/uploads/2013/01/muzzle-energy.png) directly *inside* the body. [Answer] You need to have encapsulated antimatter projectiles: these will effectively be super-explosive bullets with yields equivalent to tactical nuclear weapons (or less, if you want low-power weapons). Otherwise, as others have mentioned, interaction with air will be a problem. ]
[Question] [ I'm about to flood the planet with magic, which doesn't play nice with tech, especially power. The only places tech will still work are Null Zones which cancel magic due to deposits of minerals (the specific minerals are still undecided). When this flood of magic hits, power fails instantly, with no chance for the "proper" shutdown of nuclear reactors. How can I determine the exclusion zones this would create and the death toll from radiation poisoning? [Answer] The Fukushima incident is a good model for what happens when a nuclear power station loses power. At Fukushima the reactors safely shut down following the Tohoku earthquake, but this only means that the primary uranium reactions stopped. The nuclear fuel continues to generate heat due byproducts undergoing radioactive decay. [This decay heat is significant](https://en.wikipedia.org/wiki/Decay_heat), so power must be maintained to coolant pumps even after a reactor shuts down. If that power is not maintained then the shut down reactors can/will still get hot enough to melt. All existing commercial reactors need active cooling after being shut down. If electricity stopped functioning then the coolant pumps would stop working, as well as their backups (which are diesel generators and batteries) and the reactor would quickly get dangerously hot. The loss of electricity does not necessarily imply that the radioactive decay would also stop, as radioactive decay is a function of the weak nuclear force, while electricity is a function of the electromagnetic force. As the reactor gets hotter the coolant (typically water) would boil off as steam, increasing the pressure inside the reactor. This pressure would be relieved through emergency pressure release valves, but without active coolant flow the nuclear fuel would soon become uncovered and uncooled. High temperature reactions in the reactor (with the zircalloy fuel cladding) would release hydrogen gas, which would also build up inside the reactor and would be released through the pressure release valve. This hydrogen gas could explode, as it did at Fukushima. Ultimately, one of three things will happen. Probably the best-case scenario is that the reactor will get so hot that it completely melts and falls into whatever happens to be under the reactor (hopefully a large concrete catchment basin designed to do exactly that). This nuclear slag will stay very hot and very radioactive for a long time, but otherwise it's not doing much. As long as you don't go spelunking inside former nuclear power plants you're going to be pretty safe. The middle-case scenario is that the plant develops radioactive leaks. Radioactive particles will get into the groundwater and into the environment, but massive radioactive contamination is avoided. People who are unlucky enough to live downstream or downwind will have an elevated lifetime risk of cancer, but radiation-induced cancers have a latent period of about 30 years, and the actual incidence of cancer from long term low-level radiation exposure is generally very low. (About 40% of the healthy population in the world today will end up developing cancer, and about 20% will end up dying from their cancer. The natural prevalence of cancer is very high among the healthy population, so low-level radiation leaks will change that picture to affect more people and younger people, but the underlying reality won't actually change.) The worst-case scenario is massive contamination such as what happened at Chernobyl. A steam explosion or similar mechanism rips the reactor apart and spreads radioactive fuel over the nearby countryside. However, your mental image of Chernobyl is probably a lot worse than it really was. Even without cleanup, the majority of the radioactive contamination would have been limited to the area immediately around the nuclear plant (less than a half a kilometer). People who venture up to the reactor complex itself could easily get lethal doses that would kill them in days or weeks, but if you never go up to the reactor site then you could just treat everyone else like they're exposed to low-level contamination like in the middle-case scenario. Now, most western-style reactors are built inside a building called a containment building. This is designed to prevent any major radioactive release even in the event of a total core meltdown. As far as we know this mechanism will largely work, and even if containment is breached, it is likely that those breaches will be leaks instead of catastrophic damage and massive radioactive contamination. However, not all nuclear reactors (notably those built in Russia and the former Soviet satellite states by the USSR) have this containment. The Chernobyl reactor did not have containment- the reactor building was essentially a large metal shed you'd find housing any other piece of industrial equipment. When the Chernobyl reactor had a steam explosion it ripped straight through the building. What this means is that western-style reactors are probably immune to the worst-case scenario given above without additional plot intervention. As far as how big those exclusion zones would be- Fukushima eventually had a 30km exclusion zone, but that is a very generous exclusion zone designed so that people would be exposed to absolutely zero additional radiation. Aside from a few hotspots outside the reactor complex there was no significant threat of acute radiation syndrome that would cause radiation poisoning or death (the dose rates mostly recorded were in the range of 10-50 uSv per hour- well below the threshold even for long term cancer risk). [Answer] # None at all today There are no graphite-moderated reactors like Chernobyl operating today, we use Light Water Reactors, or occasionally, Heavy Water Reactors *CANDU (Canada Deuterium Uranium)*. Because of this, unless your magic turns water into graphite, there will be no reactor core melt-downs. If you immediately kill power to any nuclear reactor, the poison control rods, which are held up by electromagnets, will immediately drop into the core and absorb nearly all neutron radiation. The process is called "Scramming" the reactor. Control rods are called "poison" because they kill nuclear reactions. They are made of halfnium, which absorbs neutrons; reactions shut down instantly. Because of this, there will be no residual radiation from reactor cores. **[Caveat: Control rods do rarely get stuck and fail to fall. The water in that one section of the core could increase reactivity to a critical point in commercial reactors (but not military ones). The normal procedure here is to drain the water out of the core, but you have to do this manually since you killed electricity. So there is a possible scenario where a small part of one reactor “melts down”, creating a groundwater issue. The plant has tanks that will hold the contaminated coolant if they drain it in time.]** No radiation leaked from the core at Fukushima, [the contamination came from cooling water](https://en.wikipedia.org/wiki/Discharge_of_radioactive_water_of_the_Fukushima_Daiichi_Nuclear_Power_Plant#:%7E:text=Immediately%20after%20the%20disaster,-On%205%20April&text=In%20May%202011%2C%20another%20300%2C000,PBq%20of%20Caesium%2D137%22.) that came out of it when the earthquake and tsunami broke coolant pipes. Water with radioactive elements in it were dumped into the Pacific Ocean. Unless your magic can break coolant pipes, you won't have any Fukushima-like damage. Instantly shutting down all electricity on the planet will not cause any radiation leakage today, however, slowly, since we will not be able to pump or process radioactive water, we will have an impossible cleanup and containment problem. They may fence off all reactors and abandon them, letting their pipes rust and leak. It would become a small local exclusion zone in a few decades. # How to create a disaster If your plot needs a nuclear disaster, you could magically freeze all water at power plants. The ice will destroy all the pipes and also prevent the control rods from falling. The ice will still moderate the reaction, and the reactor could go into a prompt critical state. As the ice melts, it would start at the bottom. Cold water is the absolute worst thing for reactors, because it is more dense and increases reactivity quickly. This would cause both a meltdown, break the containment vessel, and leak all of the coolant water into the rivers or lakes that cool them. Nasty day! I am a naval nuclear propulsion operator. I maintain reactors for the US Navy. They can't blow up. ]
[Question] [ I'm wondering what kind of conditions (planetary mostly, but cultural or other such fields could work as well) would promote the development and distribution of air or pneumatic weapons over regular combustion types that we have today. Not necessarily into the modern era, but around when firearms were beginning to become the standard weapon for military use. [Answer] They would have to have developed a safe and field-easy method for compressing air, and a field-easy method for storing and deploying, prior to having developed the same for gunpowder. In addition, I suspect compressed air would have to have been be in popular household use, as saltpeter was at the time. There are a lot of good reasons to use compressed air -- Gas hydraulics to lift heavy things would be one. (We've always needed to lift heavy things; farming equipment, industrial products, pallets of consumer products, etc.), another might have to do with the change in temperature that can be achieved by releasing compressed air (all kinds of stuff needs to be frozen). And powerful low-tec manual compressors exist IRL. So, my proposal is: prior to the advent of the gunpowder projectile, an inventor with a lot of business sense capitalizes on "home-compression" technology, which is just a hand-crank compressor with a strong combination of leverage and gearing to achieve high-pressure. These products were supplemental to a related line of products which used the compressed air -- hydraulic lifters &c.. With the broad popularity of that product came incentive to innovate and come up with faster low-tech means to make pressure. Soon, slow and quick release containers were developed which could contain high pressure and safely release it at varying speeds for various applications. It doesn't take long for people to realize that quick-release containers are capable of launching nearby objects at dangerous speeds, and this is weaponized as soon as it is discovered. Maybe it starts with something smaller than a canon, but larger than a handgun, but it quickly develops into projectile-launchers analogous to both. [Answer] The most probable cultural factor to lead to airguns being more common than firearms: Have a culture who both develops the basics of advanced metal working before anyone develops reliable gunpowder, and who held a long standing tradition of the use of blowguns. This can be further reinforced by environmental conditions that do not greatly favour early black powder usage. aka, it rains a lot. --- Air guns are effectively a mechanization of the humble blowgun. Someone discovers that they can use some mechanical means to compress air such that they can drive a blowgun dart farther or faster, and the advancement and traditions continue. --- If an early and effective air gun and its required machining is introduced prior to the local development of very early firearms, then there is limited incentive to go down the firearms line of thinking. Drawbacks to early firearms include * Reduced visibility due to smoke * Reduced ability to hide, due to smoke * Barrels readily foul * Powder is readily damaged if wet * Powder is readily ignited all at once by accident * Powder may be unreliably set off, either failing entirely or hang-firing [Which can throw a shower of sparks... So see previous issue.] * A slow and cumbersome reload process, not entirely resolved prior to the development of the fully self contained cartridge. --- In short, once machining is developed to the point of being able to reliably produce early modern air guns and reliable compressors, there is little offered by standard firearms that is a real advantage until a smokeless cartridge is devised. And even then, there are arguable advantages to air guns. --- TL-DR If Europe was a rain forest, or if the early industrial revolution happened in South America, we may have had a long period of Air Guns as a common main battlefield weapon. [Answer] The [Girardoni](https://www.pyramydair.com/blog/2019/09/the-girardoni-repeating-air-rifle-of-1780/) air rifle was an amazingly innovative weapon for its time, being the world's first semi automatic battle rifle issued to an army for service. It had an effective range of about 100 to 150m, could be loaded and fired from the prone position and did not betray the user with the discharge or release huge clouds of obscuring smoke. [![enter image description here](https://i.stack.imgur.com/bBOA8.jpg)](https://i.stack.imgur.com/bBOA8.jpg) *Girardoni air rifle with all the user kit* The major reason the rifle left service in about 1815 was it was very expensive compared to a musket, and had reliability issues with maintaining pressure in the reservoir or having the compressed air leak out of dried seals. Some innovations in technology, such as the early development of deep die drawing could make the air reservoir more reliable (making the air tank a one piece drawing rather than brazing two halves together). A slightly sideways method of favouring air guns is the adoption and use of explosive warheads. Early explosives based on TNT were shock sensitive, so firing them out of a cannon or rifle was very dangerous, but the [Sims-Dudley dynamite gun](http://www.spanamwar.com/dynamite.htm) was developed as a work around for this. Essentially a small powder charge drove a piston down a cylinder, compressing the air inside, which was released into the main barrel of the cannon and drove the sensitive dynamite charge downrange. [![enter image description here](https://i.stack.imgur.com/dNgpE.jpg)](https://i.stack.imgur.com/dNgpE.jpg) *Sims-Dudley dynamite gun* While the Sims-Dudley dynamite gun had a very limited service life, a similar principle is used to power "[light gas guns](https://www.nasa.gov/centers/wstf/site_tour/remote_hypervelocity_test_laboratory/two_stage_light_gas_guns.html)" These devices are used to accelerate projectiles to tremendous velocities, measured in kilometres per second rather than the "mere" metres per second of conventional weapons. While gas guns are mechanically more complicated than conventional firearms, hypervelocity penetrators unstoppable by anything but the thickest armour, or capable of reaching extreme altitudes or shooting over extreme ranges (hundreds of kilometres) would make them potentially devastating artillery weapons, suitably scaled down devices would serve as anti material rifles or long range sniper weapons in the hands of soldiers. [![enter image description here](https://i.stack.imgur.com/veVEy.jpg)](https://i.stack.imgur.com/veVEy.jpg) *Principle of the two stage light gas gun* [Answer] The [Leviathan](https://en.wikipedia.org/wiki/Leviathan_(Westerfeld_novel)) series had one of the factions using air pistols due to the explosive gases used in their living blimps. Perhaps volatile gases are in common use in warfare for some similar reason, or the atmosphere itself is prone to ignition. ]
[Question] [ I'm wondering whether it's possible to create a gun that shoots some kind of shock wave to permanently damage nerve cells and instantly immobilize a hostile target but leave them alive. Would such a weapon be feasible? [Answer] There isn't such a (known) effect in the real world -- lots of ways to *temporarily* stun or paralyze a person, but none of them are reliably permanent. Permanent paralysis generally comes from severing the spinal nerves, or destroying critical parts of the brain's motor centers. It *might* be possible to build a critical homing projectile (like a tiny cruise missile, really, since it has to find the correct location on the target's head from any firing angle) to strike the subject's head and administer a large magnetic pulse, which would induce a current in the brain tissue beneath the point of contact (as with Transcranial Magnetic Stimulation, only with the power dial turned way, way up) to destroy motor pathways. While reasonably permanent, this wouldn't be reliable in its effects due to brain-to-brain variations -- some people might die almost immediately due to respiratory failure, others might only suffer loss of fine finger control, ability to tap dance, or ability to roll their tongue -- while still others with very atypical brain layout (possibly due to early childhood trauma?) might show no immediately visible effect at all. A much more reliable method, though still with a fairly large probability of unintended target death, would be a similar homing projectile that seeks the C2-C3 spinal joint and deploys a blade to sever the spinal cord; this will result in complete quadriplegia, but *usually* won't stop breathing and digestive functions. [Answer] Animals with lungs don't cope well with paralysis. Spiders and wasps and various kinds of parsitoid target things like arthropods because they don't have lungs, and even after total paralysis oxygen will continue to diffuse into their bodies and metabolic waste products will diffuse out (to a certain extent). There are long-acting neurotoxins that work well on a whole range of vertebrates, but they also stop breathing and so are rapidly fatal for those afflicted. A solution, perhaps, is a gun that shoots a sticky web with high tensile strength filaments that entagles a victim and then hardens rapidly. They're not technically paralysed, but they're not going anywhere until someone cuts them out. Against the spirit of the question perhaps, but it avoids a bunch of ways of killing the target by accident, and doesn't require precision ballistic surgery. [Answer] I suggest that permanently paralyzing an enemy soldier without killing isn't desirable in any military conflict. If one side had such a weapon, it wouldn't be long before it was obtained by the other side and by terrorists who would use it on civilians. What then would become of all of these paralyzed players and victims? Would they lay in the field and die a slow torturous death? The carnage is bad enough as it is without that humanitarian disaster. I think nanomachines will be eventually weaponized. Imagine something dust like in nature that can attach itself to the enemy, enter and temporarily block their ability to walk and/or hold a weapon by short circuiting specific parts of their nervous system. What if it just dumbed them down to where they couldn't be a threat and the effect would be easily reversable with the correct signal? There would be less carnage and plenty of prisoners for the taking. What's more, nanomachines could spread in a strategic manner from a few infected soldiers to disable an entire platoon and the allies could be immunized with a specific DNA code so as not to be affected. ]
[Question] [ **This question already has answers here**: [Perpetual fog issues](/questions/29067/perpetual-fog-issues) (3 answers) Closed 4 years ago. How could a region have a (semi-) permanent mist/fog? As close to natural as possible but possible enhancements are an option like: * Technological : can both be chemical or mechanical but should make little to no noise and should work with limited resources.(limited to pre 1900ish era tech) * Mutations: For example mutated flora that could produce something like this if (heavily) mutated. * Open For suggestions really. This mist/fog should be able to hide small nomadic groups( ~20 to 50). With hostile patrols/travelers rarely entering the area. The environment: Mainly Bogs(And other wetlands)/forests(Spruce, Pine, Beech, Oak, Birch & Ash). Located close to a sea on the northern hemisphere with a colder (but not freezing) climate. Also no Volcanoes above or below ground. Size of the area around 10,000 to 40,000 KM2 (but not everything would have to be covered at once) To be clear it's about the (possible) origin of such an event, not the effects it would have on society :) My first question here so any improvement suggestions are more then welcome :) [Answer] [![enter image description here](https://i.stack.imgur.com/b4wVi.png)](https://i.stack.imgur.com/b4wVi.png) This is a picture of the town of Grand Banks, Newfoundland. The Guiness Book of World Records states it as being the foggiest place on Earth. Here, cold sea currents from the North meet up with the much warmer Gulf Stream from the south. This creates up to 206 foggy days per year, so well over half a year of fog in total. With a little stretch of the imagination, you could plausibly set your fictional country in a cold, coastal region far up North, where a similar but stronger phenomenon happens, in order to generate almost year-round fog. Maybe instead of a warm current it's actually (underwater) volcanoes that generate the warm water that combine with the colder water to form fog, so that the fog would be even more consistent and permanent. [Answer] For a very limited area, a cool breeze blowing out of a cave system into a warmer and always-damp climate will do the job. As long as the cool side is below the dew point of the damp side, you'll get condensation -- though it might sometimes take the form of drizzle or light rain when the fog gets above ground level. ]
[Question] [ The mad scientist community is...mad, to put it kiddie-appropriately. Their logic has the tendency to make 0% sense 100% of the time (provided, of course, that they ever bring it up.) So you can imagine a field scientist's confusion when the community tasked him to imagine a hybrid between a wild bison (they never specified which species) and a wild aurochs through their bones alone because hybrids between wild bison and ***domesticated*** aurochs are so done before. The problem with that is that the scientist has observed only live bison and never once studied their skeletons, and he had never seen a live wild aurochs. (In fairness, ***NO ONE*** has seen a live wild aurochs for roughly three centuries.) In short, he couldn't tell the two species apart just by looking at their bones. In order to save his skin, he would need help from a higher power (that's us.) So, comprehensively speaking, just by looking at the bones alone, how would the field scientist differentiate a wild bison from a wild aurochs? [Answer] ## They are fairly easy to tell apart from just bones. From the bones there are several obvious differences. Well start from the most obvious and work down. the shape of the skull is an easy one and the first thing you look at in mammals. bison skulls are much wider/shorter proportionally and have smaller horns. Even a damaged skeleton will show this obvious difference. below we have an american bison skulls followed by an auroch skull. the difference holds true for european bison although the difference is smaller. [![enter image description here](https://i.stack.imgur.com/5ozHs.jpg)](https://i.stack.imgur.com/5ozHs.jpg) [![enter image description here](https://i.stack.imgur.com/CQCOC.jpg)](https://i.stack.imgur.com/CQCOC.jpg) Between the american bison and the auroch there is a big difference in the hump which is much larger in bison and has a much stronger down curve in the thoracic spine and the position of the neck is much lower, again this difference is less pronounced in european bison but still noticeable. This also gives aurochs a much more horizontal profile. General size can also be an indicator, american bison are bigger, but of course this only works if you are sure you have an adult. and the difference is almost nonexistent with european bison. If they only have a few bones this could easily lead to them being confused. Auroch tails are longer, not that you are likely to find all the tail bones. I am sure someone who specializes in pleistocene mammals can spot a few more differences. Skeleton of an auroch and bison. [![enter image description here](https://i.stack.imgur.com/AH6ZI.jpg)](https://i.stack.imgur.com/AH6ZI.jpg) [![enter image description here](https://i.stack.imgur.com/wRGjg.jpg)](https://i.stack.imgur.com/wRGjg.jpg) <http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534.6285> [Answer] I am not good to the bones, but if I look at [pictures/reconstruction](https://prehistoric-fauna.com/Steppe-bison-and-Auroch) of the two species, I can tell a difference: [![bison and auroch compared](https://i.stack.imgur.com/oWMNi.jpg)](https://i.stack.imgur.com/oWMNi.jpg) the horns make a big difference between the two. And I suspect even the way they connect to the skull is peculiar. So, go for the head! [Answer] **The European "bison" is such a hybrid.** [![European bison](https://i.stack.imgur.com/1gJnO.jpg)](https://i.stack.imgur.com/1gJnO.jpg) <https://en.wikipedia.org/wiki/European_bison> > > The European bison (Bison bonasus), also known as wisent (/ˈviːzənt/ > or /ˈwiːzənt/) or the European wood bison, is a Eurasian species of > bison. It is one of two extant species of bison, alongside the > American bison.... Analysis > of mitochondrial genomes and nuclear DNA revealed that the wisent is > theoretically the result of hybridization between the extinct Steppe > bison (Bison priscus) and the ancestors of the aurochs (Bos > primigenius) since their genetic material contains up to 10% aurochs > genomic ancestry; the possible hybrid is referred to informally as the > Higgs bison... > > > The steppe bison gave rise to the American bison and so presumably represents a more pure bison strain. The European "bison" is actually the hybrid you desire - an acient mix between auroch and bison. Possibly your mad scientist lived in the Pleistocene? [Answer] The most obvious difference in the skeleton along the "hump". As you can see from L.Dutch's image the bison has a more pronounced hump over the shoulders. While that is primarily muscle, it has a skeletal structure that is significantly more pronounced in the bison than the aurochs. ]
[Question] [ [This is not my question.](https://worldbuilding.stackexchange.com/questions/15516/computer-resources-needed-to-simulate-our-universe) In my story, I have a machine that you can connect to using electrodes. It allows one to enter a small virtual reality room where everything from gravity and electromagnetism, down to the atoms and quarks of each molecule - everything is simulated. This means that people can practice fighting exactly as though one were in real-life, but without possibility of death or injury. # What technology is needed to create a "perfect" simulation of the world in a small space? Specifically, what kind of computational ability would such a device need in order to achieve this? For this question, small space can be defined as a room about 10 x 20 sq meters and about 3 meters in height. The simulation must be able to: 1. Have objects such as apples, weapons, etc. 2. Everything must be simulated in such a way that what happens in the virtual reality would happen in real-life if repeated or replicated. 3. It must replicate the user's superpowers - even if the user doesn't know everything about how they work Assume that in my story, scientists have discovered the [theory of everything](https://en.wikipedia.org/wiki/Theory_of_everything) and that it closely resembles everything we know about in the real world. (ie approach this question as if one were to simulate everything already known or theorized about our current universe) For this story element, I'm considering having a person with a unique superpower that can touch a machine or device to make it increase its performance by hundreds or even thousands of times. Would this help explain an immense computational capability? EDIT Clarification: Not imposing limits on this machine/technology is precisely the point of the question. The machine in my story is used to help people practice and understand their superpowers. Since superpowers vary dramatically, it needs to be as precise as possible to ensure the power will work the same way inside and outside of the machine. Otherwise, someone that can turn hydrogen atoms into gold atoms in the machine might actually turn hydrogen atoms into boron atoms in real life. [Answer] For a perfectly realistic simulation, like you imagined you would have to get down into subatomic level. This way when someone punches a hole through a table the splinters are perfectly realistic to the point of being possibly indistinguishable from real life. I will take a step back, though, and instead of calculating for all the way down to quarks, I'll stay in the proton/neutron world, to make things simpler. You'd have to store the following properties in memory for each particle: * position (relative to an origin, say an arbitrary corner of the room) * momentum * mass * charge * spin Let's represent each property as a 1024 bit array. Why? For precision - if you are going to play with [post-singularity technology](https://en.wikipedia.org/wiki/Technological_singularity), might as well make measurements more precise than today (1024 bits is arbitrary, and makes measurements 2960 times more precise than 2019's IT industry standards). We also need to assign a memory address for each particle in the room. Let's deal with protons, neutrons and electrons. Why? Because then we can kinda approximate to the amount of particles we will have to deal with just by counting the mass of everything in the room. 10m $\times$ 20m $\times$ 3m equals 600m3 of air. The density of air is 1.225kg/m3 at standard conditions, so the air in the room has a mass of 735kg. Let's add two fully-clothed adults, floor, walls, a ceiling, a wooden table, some columns, some fruits, swords, for a total of an arbitrary 1,265kg. I have taken this number out of a body cavity, but it is quite believable. If we just compress the air a bit when adding all the other stuff, we have a nice, round number of 2 metric tons of stuff. Protons and neutrons have different masses, but they are close enough to one another. Let's assume a neutron for each proton and we can use an average mass of 1.673776 $\times$ 10-27 kg per particle. Let's not calculate electron mass now because I'll just approximate for now. So we have like... $$ \frac{(2 \times 10^3)}{(1.67 \times 10^{-27})} = 1.2 \times 10^{30} \mathrm{\; atomic \space nucleus \space particles} $$ If the room is electrically neutral, we'll have an electron for each proton (which are half of the particles above), so the actual total would be more like 1.8 $\times$ 1030 particles. If for some arcane reason the future people are still using bytes, we need to use a 128 bit architecture (i.e.: each address takes that amount of bits, or 8 bytes). Each particle will have its own address, which is eight bytes in the address table. Each particle will also occupy 576 bytes (1024 bits per particle property = 64 bytes per property, and each particle has five properties). So: 640 bytes per particle. $640 \times 1.8 \times 10^{30} = 1.152 \times 10^{34} \mathrm{\; bytes}$. We're talking about needing approximately 11,520 [geopbytes](https://simple.wikipedia.org/wiki/Byte). For comparison, Cisco, the largest router and switch maker in the world, claims that [in 2016 the internet finally reached a combined annual traffic of one Zettabyte](https://blogs.cisco.com/sp/the-zettabyte-era-officially-begins-how-much-is-that). A single Geopbyte would be greater than that by nine orders of magnitude. In other words, your simulation would require more than a billion times more bytes than the amount of bytes that circulated in the internet in 2016. When we reach the point where we can do that, quantum processors might already be as obsolete then as the abacus is today, so I don't even want to imagine the amount of processing power involved. Let's just say the processors will runs on Clarkean magic or handwavium. [Answer] **It depends on what the eventual Unified Theory of Everything actually proves** Right now there are two theories about how small small can go. One theory is that space is quantized at the Planck scale. This is the belief that space is made up of discrete band-limited units and that nothing exists at a smaller scale than this. The second theory is that nothing can exist that is smaller than this scale, but that things can exist that are larger that do not divide evenly down to the planck scale. According to the first theory, in order to account for everything in every situation both known and unknown, you can achieve this by using the [planck scale](https://en.wikipedia.org/wiki/Planck_length) where the universe is theoretically indivisible for any practical purposes. Your room is 1.25e+36 by 6.25e+35 by 1.875e+35 planck lengths giving your a grid of about 1.465e+107 data points. Assuming your computer is made up of molecules, you would need a computer made up of about 10 to the 40th power universes just to create a disk space that can hold all that data; so, 100% true fidelity is way way way beyond doable. According to the second theory, space is analogue no matter how small you go; so, there is actually no way for a computer to achieve absolute 100% resolution of it regardless of how many universes worth of matter you throw at the problem. This makes the issue go from intractable to truly impossible. **The good news is that the law of averages is your friend** By this I mean that when you take a sample grouping of similar things, you can make increasingly accurate predictions the larger the sample becomes. In other words, you don't need 100% fidelity to know exactly what will happen 99.99999% of the time at the macroscopic scale. One thing computers are good at doing is statistically simulating complexity and data compression. As long all of your powers rely on the **known** properties of subatomic physics, you can simplify any pattern. For example: if your power relies on a certain exotic subatomic particle made up of a particular arrangement of techni-quarks, higgs-bosons, and handwavium that binds with a certain % of standard matter to form "unobtainium" which in turn binds with a certain protein in your sweat glands, then you can simulate all of those known properties as they apply to each layer up of interactions abstracting behaviors into accurate but probabilistic output at much larger scales. EI: first you index what the subatomic is doing, then the molecules, then the cells, then the tissues, etc. In the end, your program, could simulate and abstract your entire body into macroscopic blobs of tissues represented by mathematical seeds that when pushed through the right functions are predictive of all the countless repeating structures inside of it working in tandem. Scanning your body in the detail you need to simulate it in this manner could take a very long time as the scanner samples, aggregates, tests, and resamples data, but once your anatomy is "compressed" into the system, you could run this simulation on relatively plausible computers. Because humans live in the macroscopic, having a margin of error is generally fine. If you fire a 1244.7°C ball of fire in the simulator and in real life it's, 1244.6°C, because you failed to account for a few particle of unobtainium that were unevenly distributed, who cares? No human will notice the difference making the training you get in the simulator perfectly applicable to the real world scenarios you are training for. This is also true of questions like if your power will form gold or boron. The important question here is not mapping out the exact molecular activity, but understanding the rules by which your powers work, and having a scanning method that is precise enough to capture the states where either one or the other would be true. [Answer] ## An intuitive approach It is trivial to show from combinatorics that, classically, to represent the state of one atom, you must have more than one atom (in fact, many more than one atom). The proof: Let's assume your computer's memory works by storing bits in the spin state of an atom (the type of atom doesn't really matter). Atomic spins are quantized, and can either be "up" or "down," which is convenient for building a binary system, where we can say 0 is "up" and 1 is "down." If you assume you require 32 bits to represent all the possible states of a single hydrogen atom, it will take 32 memory atoms just to represent this single hydrogen atom. In reality, for all the possible properties an atom can have, you will need a *lot* more than 32 bits. The number of bits you *actually* need is dependent on the number of properties your atom can have (spin, momentum, charge, etc...), as well as the resolution you need (the dynamic range). This implies that, classically, in order to represent a simulation of a room down to the atomic level, you need a room much, much larger (in mass) than the room you intend to simulate to contain all of your computing hardware. Even if we look at it from a quantum point of view (i.e. a post-singularity society that has created working general quantum computers), you can trivially prove that there is a 1:1 correlation. If your simulated hydrogen atom has 500 possible quantum states (a gross underestimate to be sure), and you can somehow store this in the quantum state of a real hydrogen atom, then you need *at least* one real atom for every simulated atom you want to compute, simply to store the information about its state. ## But what *do* we need then? All of these intuitive concepts about what it takes to simulate the world with "exact precision" led to a more exact formulation known as the [Berkenstein Bound](https://en.wikipedia.org/wiki/Bekenstein_bound). Essentially what the Berkenstein bound says is that the amount of information you can place in a given amount of space is limited. Conversely, it also shows that the amount of information you need to represent any physical system at the quantum level is *directly related to its mass and volume.* It also shows that there is an upper limit on the amount of processing you can do with any given amount of mass and space. The Berkenstein bound was almost immediately found to have a direct relation to black holes: Namely that if you attempt to exceed the Berkenstein bound (i.e. put more information in a given volume than it can support), your computer will collapse into a black hole! Thinking back to our intuitive thought experiment before, this makes sense. To simulate your world you need bits. If you need atoms to represent bits, and you place too many atoms together in a given volume, of course they'd exceed the Schwarzchild radius and collapse into a black hole. So what does the Berkenstein Bound say about your simulated room? Well, as we've established, the amount of information you need to simulate a given space at its quantum level is directly related to the size of that space and the *amount of mass in it.* Your question doesn't state anything about the mass in the room, but gives us its dimensions, which approximate a sphere of around 12 m3 (as an aside, rather than a cube, a sphere is the best configuration for your room as it minimizes surface area). So, by the Berkenstein bound, your room requires approximately ## **3.08 x 1044 bits / kg** to *exactly* represent at the quantum level, and this is *just* the memory to store the states of all the atoms. It says nothing about *computing* the states of those atoms. [Answer] When people think of simulation, they often go directly to brute-force solutions that puts 100% of the strain on the given computer and its parts. Which is basically summarised as "try as best you can to fool a compiled working conscious person into believing something fake is real" **A more elegant solution (or fucked-up, depending on your point of view)** would be to jam a piece of technology deep into the brain, primarily into the older parts of the brain like the thalamus; technology that everybody has and they just accept it like we accept everybody has a rectangular computer in their pockets these days, and that's that. This may well be the method in which the Matrix story practically works. **Why:** Although we definitely do not understand consciousness or what causes it, one theory suggests that a good part of it is this sort of 'compiler' or 'zipping algorithm' the brain uses to basically intertwine all of the asynchronous and occasionally contradictory information the brain deals with into a "story" it tells itself (the consciousness sort of arrives then from 'the self' getting caught-up in this compiler as a variable and source of stimuli, like a snake eating its own tail) This strange function of crushing information into a "story" means that inconvenient things like the blind-spot in your eye, the differing input times of vision compared to hearing, the fact you really really want a cigarette vs the conflicting knowledge it's increasing your chances of death, and all the rest of it. **How:** If you could essentially toss digitally-created stimuli' into the brain before this 'zipping algorithm' takes place, it's conceivable to hypothesise the brain would happily include the false-reality into the overall 'consciousness hallucination' that is our everyday waking life. Logical discrepancies and problems with the fidelity of the simulated input would just melt or be crushed away in the zipping/compiler process and the conscious creature likely wouldn't notice anything at all, *except afterwards they might have some pretty messed-up dreams when the brain is essentially de-compiling and trying to work through problems that it had tossed into the unconscious during the daily bullshit-a-thon that is consciousness.* -- edit; it's conceivable you could include the aforementioned 'messed up dreams' (if you choose to include the imaginary phenomenon at all) as a kind of increasing risk or draw-back to using the simulator too much or too often; it could hypothetically cause people to suffer psychosis, or have mental breakdowns, become paranoid, split personas or even just give them cause to believe they're -still- in the simulator, or contend that dark forces are trying to insert 'small lies' into their daily life through this embedded device (and in addition physical kill-switch that would guarantee this is not the case, if you wanted to include it, is that a 'receiver' or switch in the back of their head must be on in order to receive any kind of hallucination.) [Answer] If you need everything down to the quarks, you’ll need to simulate everything down to the Plank length $1.6 \times 10^{-35}$m and Plank time $5.3 \times 10^{44}$ seconds. That's the same length scale as strings. Assuming your theory of everything works out to be something like string theory, you will need to compute the second derivative and running first and second integral (force/acceleration, energy/velocity, and position) of all of those elements in 10 spatial dimensions (not time) Per simulated second, then, for a 10 x 20 x 3 meter room, your computer will need $2.8 \times 10^{151}$ calculations. ]
[Question] [ In my novel, an experimental airship needs to land in a field but it's in a foreign country where there was no coordination ahead of time to have people on the ground help tether it. Is is still possible for the crew to land it, and how would they go about doing so? For clarification, this would be a fairly large rigid-body airship using helium and gas-powered engines for the propellors. The ship size and crew would just need to be big enough to cross the Atlantic safely (i.e. from New York to Spain and back.) [Answer] It seems to me that an airship could have one or more motors to travel normally and then a few more motors to use only when maneuvering to land or take off, motors that could turn widely to move the airship up, down, left, right, forward, back, as needed. And possibly the airship could have harpoon guns to shoot harpoons deep into the ground and then the airship could winch the harpoon lines to take it up or down as desired. There would have to be some way to make the harpoons let go of the ground when the airship was ready to leave. And possibly the airship could have several large drones and remote pilot them down to he ground to make connections. Each drone could carry a large screw and ring with a line attached. Each drone could have a device to mechanically screw the screw into the ground. When each of the rings was screwed in tightly the airship could winch the lines attached to the rings to lower itself. I have read that early airships needed large ground crews where they landed to grab the lines lowered from the airships and use those lines to maneuver the airships to land. And I read that modern developments make the necessary ground crews much smaller. So possibly the airship could carry the necessary ground crew and lower them to the ground so they could help the airship land. Some Zeppelins used for bombing in World War I had what were called "cloud cars". The Zeppelin would hid from defenders above a cloud bank and lower the cloud car through the cloud to clear air. The observer in the cloud car would phone instructions up to the zeppelin to reach their target. I couldn't believe my eyes when I saw the use of a "cloud car" in *Hell's Angels* (1930), but they were actually used. So an airship should be able to have devices to lower a small ground crew and equipment to the ground. And an airship would normally have its helium in many smaller gasbags inside the main envelope of the airship. And possibly some of the helium could be sucked into smaller tanks where it would be more dense, while outside air was let into the spaces around the deflating gasbags. Depending on the situation, maybe some of the helium could be let out into the outside air and lost. Either way, the airship could gradually become heaver than air, helping it land. Some combination of the above might be used by an advanced, futuristic airship. If you want a contemporary or futuristic airship, you should find an expert in how they operate. And if you want an airship from the past in a story set in the past, you will have to find accounts of how they operated, and perhaps make a character a brilliant inventor who has a better method for landing airships. [Answer] Simplest one I can think of: a small gondola on a winch cable is used to lower a landing crew and collapsible mooring mast while the ship hovers (a headwind makes this work much better), then the ship circles while the crew assembles the mast and make ready to capture the ship. [Answer] Your airship could have one collapsible helium ballon inside the rigid structure, between two (or more) always-inflated ballons. If you want to go down, pump helium out of this balloon into canisters, letting air into the superstructure, thus making the airship heavier. Reverse to go up. Or you could make this balloon a hot-air balloon: Let hot air out to go down; turn up the heat to go up. Besides allowing the airship to land on the ground (where it should be carfefully secured with mooring lines), it also allows changing altitude. [Answer] One of the reasons for large ground crews with classical airships is the huge surface area makes them act like sails when close to the ground. You want to secure the length of the ship so it isn't being pushed or bent by the wind. [![enter image description here](https://i.stack.imgur.com/Or9JU.jpg)](https://i.stack.imgur.com/Or9JU.jpg) *USS Los Angeles having a bad day* [![enter image description here](https://i.stack.imgur.com/NV5It.jpg)](https://i.stack.imgur.com/NV5It.jpg) *Ground crew* Now while it is technically possible to have harpoons or other forms of ground anchor carried on board, you need to consider that airships actually had very limited lifting capability. Even an airship the size of the Hindenburg could only lift about 80 tons, and this would include everything from fuel to paying passengers. If a significant amount of weight is included for landing devices, then the revenue carrying portion will suffer. By contrast, giant airliners can weigh 200 tons fully loaded with passengers or cargo. [![enter image description here](https://i.stack.imgur.com/FvW2e.png)](https://i.stack.imgur.com/FvW2e.png) *Size comparisons* Another consideration is that if the devices are rocket powered or fired by cannon, then there is also a risk of fire damage to the ship, and especially danger of destruction if the ship is filled with hydrogen (the Hindenburg had to use hydrogen because the US embargoed helium sales to foreign nations). Perhaps the only way to make this work is if the engines are designed to pivot and allow the pilot to use direct thrust to climb or descend. While somewhat heavier and more complex than other systems, it is not as heavy as separate landing systems and provides more positive control over the airship than the classical systems of basalt and venting lift gas. [![enter image description here](https://i.stack.imgur.com/fx8yF.jpg)](https://i.stack.imgur.com/fx8yF.jpg) *While not an airship, this [Curtiss-Wright X-19](https://en.wikipedia.org/wiki/Curtiss-Wright_X-19) demonstrates the principles of using thrust vectoring propellers* So a classical airship with engines or engine gondolas designed for thrust vectoring by moving the propellers could have the ability to do controlled landings and take offs even in unprepared fields. [Answer] Like sailing ships, an airship could drop several anchors to secure their position. Unlike sailing ships, the anchors aren’t heavy. They could be either grapnels or spear-like. They could cabled and connected to winches and the hooked on trees, rocks, or fired into the ground. Using two or more points, the airship could pull itself near enough to the ground that the aircrew could shimmy to the ground, and secure the vessel to the ground more permanently. The grapnels and spear-like things could be recovered since they were to temporarily stabilize airship during landing. ]
[Question] [ The setting is a classic layered mega city type deal, lotsa concrete and steel and oily dirty pollution. I've got some non-fantastical options to work with. Steel frameworks, sheetrock, fiberglass insulation, rapid printed concrete exteriors, and steel meshed double pane glass. Really nothing that might not be considered for an inner city building. I basically want to narrate a person knocking their way through a wall during an escape, and I'm wondering if there's anything to add to help add flavor. Are there any more interesting options for interior walls and exterior facades? Any general ideas for how buildings might be built in a highly vertical cityscape? [Answer] You have the obvious interior elements of wiring for power and possibly networking -- not everything needs wireless. And, water and sewage pipes. Air conditioning might be handled locally into the apartment, with cooling fluids pumped around the building from a central location. Similarly, electricity might be operated at very high voltages to minimize current losses, meaning the apartment would have step-down transformers and rectifiers, or the power might be high voltage DC, then the apartments would have static inverters to convert to AC or different voltage levels The walls might have fiber optic cables with integrated sensors for monitoring the building's environment for vibration (structural failure), smoke, fire, chemicals Outside units might have solar cells integrated into the glass or walls, and that means the structure would need proper power distribution systems to support mixing power from public utilities with power generated from different exterior walls as the sun transits the sky. [Answer] Recent developments in modular construction, especially recent factory-pre-assembled room modules now being employed in hotel construction suggest you may in the future see a lot of double-walls between units, some light-gauge steel studs between heavy-gauge steel structural members, all supporting interior sheetrock (or equivalent) with blown cellulose or glass-fibre insulation or sheets of rigid polyisocyanurate insulation, all with cold and cold water piping, waste water piping, power and data in flex conduit with connectors at each wall intersection. Think steel lego assemblies which stack and align. To see what I mean, look up on You Tube the B1M channel and look for the video on the new Modular Marriot which is going up as we speak: [B1M YT vblog article modular hotel](https://www.youtube.com/watch?v=J8m_XURNbKY) It's also worth recognising that one implication of this kind of architecture is that as it becomes more common, the reuse of shipping container approach which has failed to gain traction will become *far* more attractive - and so you might well see mid and high rise residential structures where the main structural components are super-heavy gauge steel (in scale with what you see in a bridge or super-high tower) and those create an accepting framework which accepts the shipping-container-sized modules and locks them in place. These larger frames need not be rectilinearly-aligned beyond the scope of the individual modules, depending upon the nearby structures and space envelope constraints - so you might see some very strange twisting leaning overall building envelopes, as long as all the forces balance and the overall structure can withstand rain, wind-loading (a huge deal in high-rise constructions) and whatever seismic forces can be expected on that specific site (so if on the ring of fire expect huge triangulated trusses, both horizontal axis and vertical) so your characters will need to be able to navigate between the larger steel members, possibly knock out light-gauge steel studs, cut through polyiso rigid sheet insulation or tear through blown insulation and avoid power conduits and PEX or BPEX flexible water piping; if the building was lower-cost and did reuse shipping containers, there might still be medium-gauge steel sheeting at the centrelines of the double walls between units too. Hope that helps. [Answer] **Graphene windows.** [![enter image description here](https://i.stack.imgur.com/HCW5u.jpg)](https://i.stack.imgur.com/HCW5u.jpg) <https://www.phonenomena.com.au/blog/2014/05/29/graphene-will-change-the-future-of-mobile-technology/> > > What is 200 times stronger than steel but six times lighter, a better > conductor of electricity than copper or silicon and the next material > of choice for electronic devices? > > > Your near future buildings have superlight, super tough graphene windows. Additionally these windows do not necessarily show what is outside - they allow light to pass but might serve as a video screen, showing an image of an idyllic outdoors like a seascape or a meadow. Graphene is nearly unbreakable and would also be difficult to cut; efforts might first disrupt the integrated electronics and video feed, showing what is actually on the other side of the window. ]
[Question] [ This is a small civilization (more than just a town or two) almost under the shadow of the regional hegemon. The dominant civilization knows they are there, but don't go too deep into that swamp because they are so outflanked every time. How could I have a set of normal humans be adept at getting around quickly using methods others can't? At least, not just infrastructure that an invading army can also use to good effect. No magic, unfortunately, although there could be some post-apocalyptic technology used. [Answer] **Depending on your swamp there are two key pieces of information:** 1. Routes where the water is always shallow enough and the ground firm enough to walk 2. Routes where the water is always deep enough to use a small boat A swamp is a maze without definite pathways. The conditions of the above routes could repeatedly cross each other without interfering, but knowing both is the only way to move easily through the environment. Of course for the former you could set rocks or logs into the ground at pace distance on predefined routes. Fully, permanently submerged wood lasts a remarkably long time in a swamp type environment without needing much maintenance, and a little careful seasonal dredging never hurt the latter. Permanent residents should certainly be considering both maintenance options. --- **Beware:** There's a key technical limitation to using a swamp as your primary defence. Swamps can be very easy to drain. If the tribe is too irritating to the hegemon it becomes worth doing, and he can cut off the water and dry them out before attacking. The skills required have been available for thousands of years, the Romans did a good line in draining swamps, the Dutch are specialists at reclaiming land from the sea and have been for centuries. Put in a dam and divert the river feeding the swamp, or run a dyke round the coast means no more swamp and no more passive defence. A tribe hiding in the swamp, not paying taxes and harbouring the odd criminal is one thing, actively attacking the hegemon from the swamp base is quite another. [Answer] It seems to me the tactical advantage they'd have would be first and foremost knowledge of the terrain. If they've been mucking about there as nomads for a while, they'll have learned where the (and I'm guessing at wildlife, so please allow for these being examples) 'gators hang out, where the birds nest, how to watch for water moccasins, and what to put on their skin (and how to dress) to keep the bugs off. They'll also know where the sinkholes and quicksand (or fast-acting equivalent) is, where the water flows with an actual current, how to find stable land, and where to find or how to scavenge for food. This is going to be key to any battle, especially a lengthy one. On one side you're looking at an army--likely armored, which is the *worst* thing you can wear in a swamp--eaten up by bugs, possibly falling ill from bad water or the viruses the bugs may carry, being picked off by dangerous critters that hide in the water, and sooner or later running low on rations. On the other you have the natives, well able to booby trap their swamp, adept in knowing where to step and how to survive, well fed, often well rested, and able to vanish when the going gets rough. Even if the attackers are technologically superior, the nomads have more than a fighting chance at winning, especially if they hit them with guerilla warfare instead of a head-on confrontation. Of course, the easiest adaptation for using a method others can't might just be swinging on well placed vines or ropes--it takes practice to use those right and not whack into a tree. Rope bridges way high up are also a time-honored form of transit and ambush, so long as they're hung well out of the reach of saboteurs. [Answer] If your swamp is a very hostile environment where the Swamp Rats have culturally adapted to as a matter of survival then beyond detailed knowledge of the terrain, they'll have skills that make them dangerous foes. (1) Since they hunt in the swamp, they learned how to move without disturbing nesting birds. This lets them take their prey without warning. A large dry earth force wouldn't have those skills and knowledge and could be easily tracked from all the birds and bats they spooked as they moved around. The size of the force might be discernible by the size and number of the avians taking flight. (2) Again, since they hunt in the swamp, they are natural croc-whispers and anaconda-whispers. They know how to move to avoid triggering their predator-prey response or scaring them monsters into attacking. If there are other giant and really dangerous creatures like 20' water buffalo living in the swamp, so much the better. They'll be giant-dangerous-creature-whispers too. The large force will need to guard against the creatures. (3) If the swamps are prone to tidal or sudden flooding, then the settlements might be mobile, built on a combination of house-boat and wheeled structure. This another place were being creature-whispers works out for them since they can capture and harness the monsters to help them move around. Then let the creatures go. (4) They'll understand the flora of the swamp and know which things are poisonous and which are edible and which are medicinal. They could coat their weapons in the poisonous ones, eat the good ones which would give them enviable logistics in a campaign. They might be able to sneak the poisonous ones into the water carriers and food supplies of the invaders by sneaking into their camps at night. ]
[Question] [ Inspired by [Personal Teleportation as a Weapon](https://worldbuilding.stackexchange.com/questions/142436/personal-teleportation-as-a-weapon) Using the teleportation rules from that question: > > 1. The Teleporter can teleport themselves and/or any object (including people) they are touching, with a total mass limit of roughly double their own mass. > 2. People/things/self can only be teleported to places which the Teleporter has previously visited in person. > > > How could a group of people tasked with defending a person defend them from an attacking teleporter the size of an adult human? Assume a near-future world. Update: for simplicity sake: assume the teleportation method is a mutation similar to Nightcrawler in the X-Men as explained in <https://en.wikipedia.org/wiki/Nightcrawler_(comics)#Powers_and_abilities>: * Can teleport to any area within 2 miles with pinpoint accuracy; * Can teleport to any area he's been before outside that zone with pinpoint accuracy; * Teleporting into matter causes injury and/or death, but teleporter can sense areas where this can cause issues before the teleport (sense sharply drops with distance); * Teleporting is through an external dimension. This is not a duplicate of "[How do I protect my shop from teleporters?](https://worldbuilding.stackexchange.com/questions/51444/how-do-i-protect-my-shop-from-teleporters?rq=1), because that question is about a location and I'm more interested in how to protect a person. [Answer] > > Teleporting into matter causes injury and/or death, but teleporter can sense areas where this can cause issues before the teleport (sense sharply drops with distance); > > > You need to make an area that the teleporter cannot appear in, if you have a compound with narrow corridors with soft bits sticking out that you can walk through no problem, but anyone teleporting in will end with it inside them. This could be done with hanging bead curtains or foam fronds sticking out from the walls or even turn the compound into a ball pit If you need to be outside, then turn yourself into a walking porcupine, that will stop the attacker from appearing in contact with you [Answer] **Deception** There are two stages to deception: 1. Concealment: The target's location is concealed from the attacker...and from unwitting friends and family. When the target hides in New York, *everybody not actively involved in defense* is told the cover story. "Why, she ran off to Patagonia with those strange friends of hers last week." 2. The Trap: When the attacker arrives in the remote village on the wrong side of the planet, they teleport into a series of fiendish and fatal traps: Booby traps, gas, electrified floors, snipers, old-ladies-serving-poisoned-tea, etc. Meanwhile, the target is having a lovely time elsewhere, perhaps wearing a wig or other meager disguise until the attacker is dead...and has been autopsied so everyone knows the attacker will stay dead. Then it's time to seek hilarious revenge on whoever sent the attacker. [Answer] ## A lot of problems, a yacht of solutions A yacht in the middle of ocean has no avenues of access for a teleporter who can only visit where they've been. Your VIP can live in comfort and safety. The only risk would be supply boats, but those can be monitored. [Answer] **Go to Space** Bring the People you have to defend to space, where your teleporter can never been. Nowadays, only very,very,VERY few people went to space, and all of them are known. That wont change to soon. So take the people to a space station and they should be secure from the teleporter. [Answer] **Lasers** Teleporters can detect mass but not lasers which is just light. With a personal tracking system so the lasers don't cut you, the rest of the room is crisscrossed with cutting lasers so teleporting in would be like jumping into a wood chipper. Alternatively blinding lasers would also work. You'd be wearing protective glasses but anyone without the right glasses would be permanently blinded which makes a teleporting assassin ineffective. [Answer] There are several ways: 1: Be in a location unknown to your attacker. This negates the teleporter's main advantage.... until he/she finds you. Then you are in trouble. 2: Distance. If you are far enough away, they can't teleport to you. If you have enough money, you can make a wall/solid barrier 2.1 miles thick just to prevent your assassin from getting you you in the first place. 3: Anonymity. You can't target what you don't know is there. Having a physic person to constantly make you anonymous to people/electronics around you makes you practically invisible without the side effect of blindness! 4: Counter-offer. Just bribe him/her (or use a psychic) so that you don't die. [Answer] If momentum is preserved while teleporting, put the person on a high speed vehicle with variable speeds. Sure the attacker can teleport to them, but unless they get their speed exactly right, they'll instantly be pancaked. ]
[Question] [ On a habitable world completely covered in water, with no land above sea-level, there would presumably be storms of biblical proportions. Suppose this world has oceans so deep that the deeper layers just have too much pressure for life of any kind to survive - from the planet's organisms' point of view, the sea would essentially be bottomless. **Without any seabed for shelter/anchorage, but also without any land to be beached on, would gigantic storms, waves etc. be seriously harmful to underwater creatures?** When I say "seriously harmful", I mean so damaging as to make the very existence of complex sunlight-zone life on the world dubious. Two points for further clarification: * The animals do not need to surface to breathe. * Yes, they could potentially take shelter in some kind of floating reef/microbial mat, but ignore that for the purposes of the question. [Answer] Photosynthesis can take place at depths of about 200m; so, as long as sustained storms do not significantly disturb life at those depths, then life would be fine. To understand your risks, a wave only causes major disturbances down to about 1/2 the height of the wave, meaning you'd need storms to consistently produce 400m waves to kill off all life. However, in the open ocean (under Earth's gravity), wind can generally not produce a wave taller than 10m because as the wind whips it up bigger and bigger, the wave will begin to crest and gravity will force it to collapse in on itself. For this reason, waves bigger than 10m are almost always causes by seismic activity or from being pressed up on by a continental shelf. So, in your world, even if you had massive super storms constantly raging at the surface, just 5m down you'd have relatively calm water without any continental shelves to exasperate things giving you a 195m save zone for photosynthetic life. So to answer your question, storms will not inhibit life. That said, with no readily available access to ground minerals, your world may not be able to sustain life for completely different reasons. If your planet does not have underwater mountains that reach within 200m of sunlight or some other mechanism for uplifting significant mineral content into the upper layers of the ocean, it's unlikely for you to have the diversity of elements you would need for life. [Answer] The climate of a planet is primarily driven by the energy imparted to it by its parent star and the difference in atmospheric circulation driven by the poles not rotating and the equator rotating at high speed. The most serious storms would probably occur on rapidly rotating planets with high solar input, but there is a limit to how high wind blown waves can get. If there is no need to surface to breathe creatures on such a world would be able to avoid the effects of storms simply by diving down a few hundred metres and in most cases by diving just a few tens of metres. It is hard to believe that wind-blown waves would be able to build to such intensity that this strategy would not work. Adding too much energy to the atmosphere would have the effect creating chaotic conditions in which it would be difficult for sufficiently large well-formed waves to exist as they would be hit by many other waves and variable wind conditions. [Answer] **No.** * Earth has storms of biblical proportions that happen over its oceans. Perhaps a dolphin or whale is occasionally affected, but that's it. Those storms are a much greater danger to those of us dependent on its surface. Generally speaking, I doubt it matters how big a storm gets. * Your ocean bottom won't be smooth just because there's no surface land. You'll have ridges, sinkholes, canyons, areas of shallow water and areas of deep water. You'll have currents, waves, and tides (assuming a moon). You'll (presumably, it's your world) have coral reefs. If you draw a shape encompassing our own oceans starting at a depth of, say, 2 meters and encompassing everything deeper, you'd have your world in a nutshell. In other words, there will be plenty of places to hide if you can't get deep enough. * Your sea life will have evolved on that planet (I assume, you didn't say if they were transplanted or not). They will have adapted to whatever storms your world can throw at them just as all life on Earth has done. Can Mother Nature throw a curve ball that takes out a few creatures (like a wildfire on land)? Sure! But I don't think that's what you're asking about. I believe you're asking about within-the-statistical-norm storms — the kind life would have adapted to. (This is why I don't believe it matters how large your storms get.) * Earth has depths were no life can live, but it also has a very wide band of depth where life thrives, and at the bottom of that band are depths that wouldn't know a storm was raging no matter how biblical its proportions. Frankly, I'd doubt anything deeper than 100 meters would ever now a storm was in process. [Answer] As for the storm's effect itself- no any storm wouldn't have that great an effect on the ocean life. According to [This Post](https://www.reddit.com/r/askscience/comments/15b1jo/how_far_underwater_do_the_effects_of_a_storm/ "How far underwater, do the effects of a storm extend?") on reddit any effects on the surface of the ocean reach about 1/2 that depth, with exceptions for phenomena caused by the ocean floor (e.g. a Tsunami). That being said, if your ocean floor is over about 26,000 feet deep [SOURCE](https://www.forbes.com/sites/shaenamontanari/2017/08/29/adorable-fish-seen-at-the-deepest-ever-depth-in-the-ocean/#664d5517737b "fish seen at the deepest ever depth in the ocean - Forbes"), then life in general is going to have a hard time existing. That being said, they're still going to need something like geothermal vents or ocean fissure for it. That's because of mineral loss over time, since any creature that dies would sink to the bottom of the ocean, and since nothing can get down that low to retrieve the mineral nutrients, slowly leeching it out of the ecosystem. (at the very least, nothing particularly mobile, I couldn't find max depth on micro-organisms or non-sunlight dependent plants). So unless you've got something stirring up your ocean floor, two things will happen: 1. The ocean will slowly become freshwater from all the minerals being effectively locked in the ocean floor. 2. The ocean will slowly become devoid of life from the lack of minerals necessary for life (like potassium and iron). ]
[Question] [ Technological level - similar to contemporary. Yes, I mean a watercraft, mostly big cargo carrying ships. I mean only calling for help while being in middle of ocean and not being within line of sight distance of shore transmitters. Seemingly straightforward question, except: * flare stars and telecommunication satellites do not mix well, and low population density means that local population would not afford frequent satellite replacement * sure, they can use good old fashion radio... except that flares tend to knock out ionosphere propagation window for short waves and bring extra background noise on medium waves (if this premise is incorrect please correct me in answer) * any system that uses insane amount of energy has limited functionality as it requires ship engines to be fully functional (you can only call for help if you ship is in good shape, sure it's better than nothing...) * a suggested system can not be more expensive than just accompanying each cargo ship with a small, ocean worthy emergency rescue ship [Answer] **Moon bounce** <https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication> > > The "moon bounce" technique was developed in parallel by the United > States military and the Hungarian group led by Zoltán Bay in the years > after World War II. The first successful reception of echoes off the > Moon was carried out at Fort Monmouth, New Jersey on January 10, 1946 > by John H. DeWitt as part of Project Diana. It was followed by Zoltán > Bay's group on February 6, 1946. The Communication Moon Relay project > that followed led to more practical uses, including a teletype link > between the naval base at Pearl Harbor, Hawaii and United States Navy > headquarters in Washington, D.C. In the days before communications > satellites, a link free of the vagaries of ionospheric propagation was > revolutionary. > > > The moon is handy. It reliably shows up for work. It is intrinsically resistant to solar flares by virtue of being a giant hunk of stone. The "vagaries of ionospheric propagation" is what you are trying to work around. I thought this was antique tech but apparently not. Ham radio hobbyists do moon bounce transmissions routinely! <http://www.rfcafe.com/references/electronics-world/ham-radio-earth-moon-earth-contact-october-1960-electronics-world.htm> [![first moon bounce](https://i.stack.imgur.com/pPtk6.jpg)](https://i.stack.imgur.com/pPtk6.jpg) > > What is today a routine operation by Hams was a big deal back in the day. > The moon was still a mystery to most of the world since at the time > not even an unmanned probe had been sent for exploration... The first > amateur radio moon-bounce two-way microwave communication > took place on Sunday, July 17 (1960) between two distant points. This > contact marks an important milestone in the development of amateur > radio... > > > After months of personal effort by the radio amateurs concerned with > this project, signals were transmitted in both directions on 1296 mc. > The equipment was then refined and the first successful two-way > communication was made. The first transmission was from West (W6HB) to > East (W1BU). The pattern was then reversed and the first amateur > coast-to-coast communication via the moon completed. > > > If amateur radio enthusiasts could do it in 1960, people in your world can do it. Maybe on your world Earth-Moon-Earth communication continued to develop because satellites were impracticable for the reasons laid out in OP. One could have various channels. Your ship would broadcast its distress message to the moon. On land at various points are receivers for various moon-bounce channels. One of these will received the bounced message and reply appropriately. [Answer] Your world, despite being labeled as contemporary, is practically stuck to the pre-Marconi era when it comes to radio communication. Therefore the available options are those which were available in those times, plus something which we have developed in the meantime: * emergency fireworks: fire one high in the sky when in distress, and hope someone will notice it and will come for help. Color coding can be used for hinting the kind of help needed. * patrol ships on the most used routes, to increase the chances of catching a call for help. * rescue ship, as you mentioned * in lack of the above, pray/worship the applicable divinity [Answer] A line of sight communication would be possible, but to be feasible it would be necessary to have high altitude drones (opportunely shielded) or balloons. [This site](https://dizzib.github.io/earth/curve-calc/?d0=1000&h0=6000&unit=metric) calculates the necessary height of a receiver (target) to overcome the curvature of Earth surface, given the sender (eye height) and target distance. In this idea, all the harbour cities should have repeaters mounted on tethered balloons or drones (the latter less probable, since they would suffer interferences from the flares), while all the ships should have a kind of cannon that can shoot a repeater-containing bullet (or a balloon) to high atmosphere, where it could launch an S.O.S signal. This signal could be received by the ships near (for instance if it can reach 2 kilometers of height, it could send a signal to all ships within 160km) or by the harbour cities, which could then send help. An air patrol along the most important commercial routes (held by something like a U.N. organization) could also prove effective in collecting and responding to help requests. Of course, given the fact that the planet has a sparse population, it is possile that the average distances from a ship and another ship/harbour are a lot higher, making this option useless. But I'm afraid that if this is the case, any help would probably arrive too late to be of any use... However I think that in a world like yours, thw ships would likely form convoys and follow some pre-established routes (even if longer than the most direct paths), to maximize the probability to be rescued in case of danger. [Answer] This calls for **whale song**! At a few Hz, Bandwith is not plentiful, but: You only need 1 Byte for type of emergency (from a list of 255), 7 Bytes for sub-m² (!) localisation on an earth-sized planet, 2 Bytes for a caller ID (from a list of 65k, or three Bytes for a list of 16M). A message of ten Bytes means you can really go to town on the redundancy, even on a channel with whale-song bandwith. Sound of very low frequency carries for 10.000 miles, meaning you can probably reach at least a substation that relays the info. Sound travels at about 1500m/s in seawater, meaning (1) it's fast enough so a signal would only take a few minutes to reach the next substation (2) it's slow enough so you will not need ultra-synchronized clocks (which might be tricky beneath a flare star) to get a very good triangulation (to get a sanity check on the location given in the code); Whale song needs to be inserted into certain layers of the ocean, so this will not work if your ocean is very shallow (or composed of very small deep bits connected by shallow bits), or you cannot access these layers for some other reason (inhabitants ...). Substations can have permanent access to those layers via a hanging cable, ships may access them by dropping capsules (either throw-away, or tethered). Depending on the havoc the flare star wreaks on the surface, ships might feel more comfortable as subs anyway, which would put them in reach of the transmission-layers from the start. [Answer] How many of these ships does this planet have? On and around the busier shipping lanes I'd expect hardened and automated relay stations that can pick up weaker signals from backup systems. You could also have solar-powered buoys acting as the same. If they are truly out of the shipping lanes and away from any way to relay signals: sacrificing roosters and/or the cabin boy used to be a popular option I believe. ]
[Question] [ Setup: A planet generally with an earthlike climate, although slightly wetter and warmer as a general rule, with a little more oxygen in the atmosphere, but habitable by unmodified humans. Still has equatorial and polar variation. Planet has constant winds. Stable enough long enough to have evolved a sapient species with an adequate level of technology to completely contain expansion of a refugee colony of humans of mildly (but nonspecified) post-modern tech. What good reasons could there be for this planet to have, multiple times per year, on either a completely or semi predictable schedule, extended periods of hot, dry, dusty winds that cause native life to generally close up and hide? This does NOT have to be planetwide, but does have to be prevalent enough that the sapient species and most others have evolved strongly adapted to it. By extended, I mean at least long enough for a caterpillar like metamorphasis of several hundred pound creatures to occur. Solar year can be significantly longer than earth's, and the dry winds don't necessarily have to be connected to any other function of regular seasonality, ie not necessarily during a 'summer' or whatever. They should be predictable by at least several days however. Edits: There is no need for the planet to be based in any particular kind of orbit as long as it meets the rules. The setting is more science fantasy than hard science fiction, so answers don't have to be super strict on hard science, as long as they make general sense. The best answer will incorporate either an irregular cycle, or a cycle that is regular on such a long timeline that it is difficult to perceive, or a regular cycle with potential for intermittent irregularity. These periods would typically occur no less than 2-3 times in a solar year. The hot dry spells would not be so extreme as to be immediately dangerous to most creatures, but would be a severe stress over time if not protected/sheltered from in some way (ie walking around the Sahara unprepared) [Answer] **Not very stable star** could provide the answer, but the planet would have to have fairly strong magnetosphere which would present other problems. Other solution might be **multiple star system** as mentioned in one of the previous answers. Since the planet does not have to be a planet but can be a moon (by your specifications) I would imagine that if it was a **moon of hot Jupiter** on a fairly elliptical orbit. Depending on the exact orientation of the moon's orbit, its speed and eccentricity these changes in temperature can be caused by varying distance from both the sun and the parent planet with strong **tidal heating in the perigee** and then strong **influence of the star in the planets perihelion**. **Example:** The Planet is elliptical orbit around its parent Binary star while remaining in the habitable zone. The varying distance of the planet from each of the stars would cause different temperature on both the planet and its moons across multiple orbits. The Moon orbits the planet in its own elliptical orbit, heating up in the perigee, cooling down in the apogee - this would cause periodic temperature changes during the year, while changes caused by planet's orbit around the parent stars would cause temperature changes with a longer period, making them seem "random". ... How stable such a system would be - that's a different question. **Edit:** After some fidgeting in *Universe Sandbox 2* I have been able to find a fairly stable system that somewhat matched the specifications. [Answer] If you have considerably longer days, then it's possible that those days become seasons. Let's say your planet rotates 3 times per 'year'. Sure, your days and nights are much longer and that's going to cause all sorts of havoc on your ecosystem (although it would go a long way to explaining the constant winds), but it also means that the day and night cycle would factor in to your seasons by virtue of the axial tilt. If you're in daytime in the Northern Hemisphere while the tilt means that you're at a normal summer period, you have an intense summer. By the time it goes to night, you have a relatively moderate 'winter' insofar as you're closer to the light horizon. Next, you have a moderate summer/autumn, then a bitter night winter, then a moderate spring/summer 'day', then a moderate night winter again, etc. In other words, a slow rotation means that your days and nights occur at different phases in the axial tilt, causing different degrees of intensity during your year. [Answer] Wind in general is caused by temperature variances in an atmosphere, and constant wind could possibly be caused by a sun that shines unevenly, with spikes in heat and light. In fact, uneven radiation or perhaps solar flares could result in periods of heat. Perhaps the sun darkens slightly before it flares, and that's how native fauna know to metamorphose? [Answer] Some other body would have to impart heat for only a portion of the year. I could imagine some sub stellar mass black hole out at ~10-100 AU away evaporating, giving off energy. Being a black hole, which at this point in its life does not have an accretion disc, would not be necessarily visible from the planet. As the planet orbits, once a year, it would come closer to this object, causing a planet wide temperature increase. Now, depending on the planets axis tilt and which part of the sky this object is in, potentially one half of the planet would effectively have 2 summers, even though the actual day is shorter in its second summer, and the other half would have a scorching summer and a cooler winter. Now if the object is >100 AU and in alignment with the equinox, than it would not give you this double summer effect, just a warm spring/fall. At this object (or the parent star) orbited, this double summer would shift year by year from the above "scorching summer" to a warm equinox and back to a double summer. all depends on the second objects orbital period. [Answer] A planet orbiting around a binary star system could have multiple warm periods as its orbit takes it closer to each star. Each star orbits the common center of gravity faster than the planet, resulting in multiple summers. [Answer] I have been mulling over the comments and answers and other astophysical speculation off and on since I asked this question, and I think I have a workable answer: The habitable body is a moon of a gas giant. it has a decent magnetosphere and protective atmosphere and orbits in a timely fashion to cause a relatively earth-similar day and night (albeit with an enormous extremely bright "moon") Sometimes, other bodies orbiting the gas giant come close enough to interfere with the magnetosphere and it flexes and causes gaps/thin spots in the protective layer, which allow an extra dose of radiation from the gas giant to get through (but not with a big enough affect as to cause massively dangerous conditions). This is a pretty flexible answer as it could be one body in particular with a regular cycle of arrival or a variety of other bodies with varying orbital periods. Also would allow a layer of natives' prediction (The Harbinger moon comes! we must prepare!) [Answer] # The world is flat\* (Turtle and elephants optional) One of the quirks of a flat world orbited by its sun is that it has 8 seasons in the year. Each season comes round twice in the full solar year. It has summer when the sun rises directly over the nearest point of the rim and again when the sun rises on the opposite side and sets over the nearest point of the rim. --- \*Full credit to the great Sir Terry Pratchett for his observations on this particular matter. [Answer] **Wind tides.** [![close moon](https://i.stack.imgur.com/ToYdK.jpg)](https://i.stack.imgur.com/ToYdK.jpg) <https://i.stack.imgur.com/jJmwH.jpg> Your world's moon is close to it. Our moon is close enough to pull on the oceans and cause tides. Your moon is much closer. It pulls on the atmosphere enough to produce wind, and the gravitational interaction together with frictional interactions of the gases in motion heats the wind. This wave of wind tide circumnavigates your world, trailing below the moon and carrying with it dust and debris. Tides are predictable. So too your wind tides. They would track with the movements of your moon. [Answer] I don't have much knowlege in this particular area but I think maybe a star or something that comes near enough to the planet to raise the temperature might be plausible. Or possibly a relatively quick " wobble " of the planets axis? [Answer] It's just IMPOSSIBLE without invok one (minimum) other star... You can along hot season like you want, but the planet are in orbit and this fact imposes constraints : cycle. you can change day rotation duration, or planete rotation duration but you can't take season where and when you want ^^ ]
[Question] [ My world has a semi-nomadic people that inhabit a vast sandy desert. Underneath this desert lie the ruins of an enormous metropolis -- a city that was abandoned tens of thousands of years ago. In the past fifteen to twenty centuries something has changed in the region which has resulted in the slow uncovering of these long-lost buildings. This process could have been going on for longer, but only in the past few centuries have the ruins actually started to surface. **What is the slow, gradual change that started this?** My first thought was a shifting of the direction of the prevailing winds, causing sand to be blown away instead of deposited, but I don't know how realistic this is. --- **edit:** The idea I have in my head is of a once-fertile region that is absolutely crammed with ruins. This city/metropolis could once have had the size and density of Paris or Berlin, for example. This city was abandoned as its people suffered some mysterious mass extinction, but its buildings and their interiors remain mostly intact, owing to the great architectural prowess of its people. The region is now covered in huge amounts of sand and has become a typical sand desert, so that nothing alludes to its former grandeur. Only recently (3~4 centuries) have the tops of the tallest of these buildings (e.g., monuments or other, rare, buildings taller than, say, 80m.) begun to become visible features in the sand. It is key that none of the peoples who have lived near the region, even for centuries, can recall it being anything other than a desert. Ideally, the uncovering would be plausible as a natural, slow event, but it doesn't have to be scientifically rigorous. I like the answer below about the flooding of Sarnath, because it explains how the city vanished (I can tie that in with the mass extinction event), how the desert was formed by the settling of salt and sand, and how the sand blows away now the sea is no longer there. The only thing I would then like to know, is what causes the sea to dry up / retreat. [Answer] **Before the metropolis was covered by the desert, it was drowned in a sea.** [![Aral Sea](https://i.stack.imgur.com/pydRL.jpg)](https://i.stack.imgur.com/pydRL.jpg) <https://www.slowfood.com/a-salt-storm-from-the-aral-sea-save-the-planet-from-climate-change/> I am thinking of H.P. Lovecraft's Sarnath, claimed by its lake. > > These men indeed went to the lake to view Sarnath; but though they > found the vast still lake itself, and the grey rock Akurion which > rears high above it near the shore, they beheld not the wonder of the > world and pride of all mankind. Where once had risen walls of 300 > cubits and towers yet higher, now stretched only the marshy shore, and > where once had dwelt fifty millions of men now crawled only the > detestable green water-lizard. Not even the mines of precious metal > remained, for DOOM had come to Sarnath. > [The Doom that came to Sarnath](http://www.hplovecraft.com/writings/texts/fiction/ds.aspx) > > > A sea claimed the metropolis, covering it in the waters. Over the millennia silt and sand built up, burying the sunken city. Years passed; the world changed. A thousand years ago the sea dried up, leaving only an expanse of salt and sand. Winds and rare rains then eroded the mudstone into peaks and spires. Like an ancient fossil, the entombed city gradually emerged into the light. <https://en.wikipedia.org/wiki/Badlands#/media/File:Badlands00503.JPG> [![badlands](https://i.stack.imgur.com/K40OK.jpg)](https://i.stack.imgur.com/K40OK.jpg) [Answer] This happens all the time over a relatively short timescale. Sand travels across the desert in wind-driven waves - these are usually described as dunes but they move. A building could be covered one day by the crest of a wave and a week later be exposed in the trough of the wave. I imagine that originally the area was a vast fertile plain and underneath the soil was alluvial rock. When the plain started to become desert, the sand gradually blew over it over hundreds or thousands of years, eventually burying the city. As the wind continues to drive the sand along, eventually the bedrock is uncovered. The foundations of the buildings were cemented to it and so they appear gradually. There is no need to change the direction of the prevailing wind. [Answer] To answer *What is the slow, gradual change that started this?* - if you're all right with it being a combination of changes, I would add small tectonic shifting to your wind changes. Tectonic plates shift gradually and only large abrupt shifts cause earthquakes. So the land could've shifted over the years and gradually led to the shifting of sand until the buildings were closer to the surface so the changes wind currents could uncover them. Now as for your second question *The only thing I would then like to know, is what causes the sea to dry up / retreat.* - Since you say your city was abandoned tens of thousands of years ago, there is room for the climate to change. Perhaps, while there was a sea covering the city, the temperature began to rise so it led to the sea drying up/receding. Similar, perhaps to the [Pannonian Sea](https://en.wikipedia.org/wiki/Pannonian_Sea) [Answer] I can't do better than Wilik's answer, but I'd like to add to it. The land flooded and the sea built up with silt and eventually dried completely, leaving only desert. As it dried, it left a crust perhaps a foot or two thick (30-60 cm). I'm thinking limestone or something similar. This crust isn't very strong but it is enough so that the winds can not blow it away. Sand builds up on the surface and blows away again, but the surface stays intact. As your nomadic peoples become more semi-nomadic, they begin to do things like till the soil, dig irrigation canals, dig wells, and set some pillars for construction underground. This activity cracks the crust over the dried up lake and, slowly, the winds are able to reach areas they could not before. The smallest of the cracked pieces blow away and so does the sand/dirt underneath. Over time, the tops of very tall structures become regular features of the desert. ]
[Question] [ Supposing a world like the Underdark, full of civilizations that developed and live their lives completely away from the light of the sun. In the typical D&D type setting, these creatures have dark-vision or infra-vision, which I recall is typically explained by sight that works in the infrared band. Upon thinking more about this, sight in the infrared band seems like it would come with several problems. This vision would be relying on the radiant emitted by [blackbody radiation](https://en.wikipedia.org/wiki/Black-body_radiation#Explanation), according to their temperature. But, the frequency band of this emission relies on the temperature of the object, so two different objects at different temperatures should look....the same? What is the science-based, biologically plausible basis for vision in the pitch-black of the Underdark, that meets the following requirements: * Operates in the infrared band * If you are walking down a curved passageway of uniform, smooth stone, you must be able to distinguish the curve in the passageway. * If you are standing in a cavern with a lake in it, you must be able to distinguish the surface of the lake from a particularly smooth patch of floor. * If you are hunting from underground mushrooms, you must be able to distinguish by sight between Ripened Feast mushroom, which tastes like cheddar cheese, and a Pustulent Death mushroom, which liquifies your skin. These mushrooms smell exactly alike, and have the same exact shape, and can only be distinguished by their 'color'. [Answer] Let me address your second paragraph: > > Upon thinking more about this, sight in the infrared band seems like it would come with several problems. This vision would be relying on the radiant emitted by blackbody radiation, according to their temperature. But, the frequency band of this emission relies on the temperature of the object, so two different objects at different temperatures should look....the same? > > > We have two key equations to consider: [Wien's displacement law](https://en.wikipedia.org/wiki/Wien%27s_displacement_law) and the [Stefan-Boltzmann law](https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law): $$\lambda\_{\text{max}}=\frac{b}{T},\quad F=\varepsilon\sigma T^4$$ which give us the maximum wavelength at which an object emits radiation, and the flux from that object. Notice that $\lambda\_{\text{max}}$ has a much weaker temperature dependence than $F$. As an example, say we have a box with one end at room temperature (293 K) and the other at the boiling point of water (373 K). The difference in $\lambda\_{\text{max}}=2\mu\text{m}$ - a small enough difference given the size of the infrared band. I would argue that in most cases, your creatures could have an eye sensitive to objects with peak emission at wavelengths from $0.8\mu\text{m}$ to perhaps $8\mu\text{m}$, covering temperatures from a bit below the freezing point of water to several hundred degrees Fahrenheit. Now, [thermographic imaging](https://en.wikipedia.org/wiki/Thermography) works because hotter objects are more luminous - recall the Stefan-Boltzmann law. Even in a range of about $1\mu\text{m}$, the changes between the two ends will be drastic. The takeaway here is that yes, you will be able to distinguish objects at different temperatures if your infra-vision depends on the net flux from an object in the infrared band - in other words, if you use the thermographic imaging method. What you need are proteins analogous to [photopsins](https://en.wikipedia.org/wiki/Photopsin), the photoreceptors used by humans to detect visible light. The three photopsins act sort of like the filters in telescopes that allow astronomers to observe an object at select wavelengths (see [photometric systems](https://en.wikipedia.org/wiki/Photometric_system), such as the Johnson-Cousins filters). The three photopsins peak at about 420, 534 and 564 nm - too short for us. However, related proteins have peak sensitivities at other bands - including non-visible bands. The protein [phytochrome](https://en.wikipedia.org/wiki/Phytochrome) peaks at far-red wavelengths (750-800 nm); it's not too far out of the question to imagine a protein peaking at $\sim1\mu\text{m}$. Indeed, [research on some species of fish](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0064429) has shown sensitivity in the near-infrared portion of the spectrum (and the sensitivity has indeed been traced back to the eyes), indicating that opsins of some sort are indeed active at wavelengths of $\sim0.8\text{-}0.9\mu\text{m}$. In short, we want a protein with a sensitivity curve roughly like the purple one below. This is a modified version of [a figure](https://commons.wikimedia.org/wiki/File:Cone-response-en.svg) based on Fig. 1 of [Bowmaker & Dartnall 1980](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1279132/). I've extended the axis and added in a qualitative example of how the opsin sensitivity should behave in the $0.7\text{-}0.8\mu\text{m}$ range: [![Modified cone response graph](https://i.stack.imgur.com/Ksopc.png)](https://i.stack.imgur.com/Ksopc.png) Original image by Wikipedia user Maxim Razin under [the Creative Commons Attribution-Share Alike 3.0 Unported license](https://creativecommons.org/licenses/by-sa/3.0/deed.en). Image modified to include qualitative behavior of the hypothetical opsin protein. [Answer] Infrared has a lot more to it than just temperature. Temperature is a major aspect, because every object emits in the infra-red spectrum. Of course, not all objects are at the same temperature. Unless your Underdark is completely still, devoid of heat sources or cyclical heating patterns (like day/night), objects are going to cool off at different rates. Large high-heat-capacity objects will be at a different temperature from small low-capacity highly-conductive objects. Your lake example is quite easy in this respect. Lakes are almost always cooler than their surroundings due to evaporation. There can also be color in the infrared spectrum. While blackbody clearly provides a fundamental limit as to what these colors can be, there's no reason one could not have a phosopholuminescent effect in the IR spectrum. Indeed, I think it might be easier than doing so in the visible spectrum, because the energies are low. You also might be able to pull of some interesting tricks with frequency doubling/halfing. You could reflect IR (like a mirror does), but half some frequencies with non-linear optics to create colors where the reflection isn't *quite* blackbody. If I were making a civilization underground, and wanted to build curved tunnels, I would almost certainly decorate the walls in a way which provides "color" so that I could distinguish where it was going. As for the mushrooms, I may have to throw that one back at you. First off, you put "color" in scare quotes, which gives great freedom in definitions. Perhaps these mushrooms do any one of these non-linear or bioluminescent effects I describe. If not, then we're into the arms race of coming up with ideas which meet the concept of "color," and then redefining color to exclude them. However, I'll point out that 100% of sentient species have figured out how to not die when eating. They might ignore the mushrooms and not eat them, just as we are recommended to avoid mushrooms unless we know what we are doing. They may also use tools. Perhaps bring a bio-luminescent light-source along to help ID the mushrooms. Once you have a light source, it's easy to see "color." Or perhaps they find other ways to tell the difference. Maybe you split the mushroom open and put a small piece of another fungus into it. If that other fungus is liquified, you probably shouldn't eat that mushroom. People are really clever when it comes with finding ways to not die. [Answer] The "infra-red band" is not a singular frequency. The way light detection works in the human eye is that we have detectors which trigger at certain frequencies. We happen to have some which trigger at roughly cyan, magenta and yellow. Say instead we had sensors in the near IR, medium IR and far IR, and we called those colours hot (think reddish), warm (think greenish) and tepid (think bluish). Looking at a person in normal light, if they are silhouetted, then yes, they do look "the same?" - but you can still see their outline. Normally, though, you can see them closer, and in the IR you'd see their warmer areas having different temperatures, and different intensities of those temperatures. Underground, in a cave, the temperature below the frost line is fairly even and depends on latitude, between about 45 and 70F in areas you're likely to be interested in. So let's call it 60F. The air, though, will generally not be the same temperature. So edges will be slightly different colors as they change towards the temperature of the air. Further, some surfaces will give off more, or less, infra red, as they are rougher, "darker", etc, in the same way that the color that you paint a radiator determines how much heat it gives off. They will also give off different amounts of different wavelengths. Some surfaces will be nearer or further away. A wall with the same smoothness will look somewhat akin to a white wall with visible light. You can still see it, you can see it recede into the distance, it's just... white. [Answer] I would recommend looking at a perfectly viable example that's been done in the real world: snakes. Many snakes (pitvipers, for instance, or rattlesnakes) have [special pit organs](https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes) in their heads, which for your purposes can be considered a set of eyes that view the far infrared spectrum instead of the visual spectrum. > > Operates in the infrared band > > > Obviously, this is covered, although it needs to be emphasized that eyes seeing the visual spectrum are *incapable* of also seeing into the far infrared spectrum: the necessary structure required is too different. No, this doesn't rule out seeing the visual spectrum as well, provided you have eyes together with those pit organs: those pitvipers I mentioned have more ordinary eyes as well, and they work just fine. Incidentally, the snakes in question have a thermal sensitivity estimated at >0.001C, so even minor temperature differences are easily detectable. Rattlesnakes actually use this vision to aim for their prey's weak points. > > If you are walking down a curved passageway of uniform, smooth stone, you must be able to distinguish the curve in the passageway > > > I believe the result will be comparable to walking down a city street at night, with the lights out: dark, yes, perhaps difficult to see at a distance, but not outright indistinguishable. You'll have minor thermal fluctuations in the stone, enough to give notice that something is there. Besides, people tend to be pretty good about not walking into walls even without having to touch them. > > If you are standing in a cavern with a lake in it, you must be able to distinguish the surface of the lake from a particularly smooth patch of floor. > > > At a distance, probably not, unless the lake is home to life of some sort. At close range, though, you should be readily able to separate the two before you actively step in the water. > > If you are hunting from underground mushrooms, you must be able to distinguish by sight between Ripened Feast mushroom, which tastes like cheddar cheese, and a Pustulent Death mushroom, which liquifies your skin. These mushrooms smell exactly alike, and have the same exact shape, and can only be distinguished by their 'color'. > > > This isn't fully answerable without a more detailed description of the differences. However, if the two mushrooms in question maintain different temperatures (for instance, if one tends to 22C and the other 18C), this would be trivial. Now, it is important to note a significant caveat to far-infrared vision. Snakes cannot see very far with this vision, and even then their visual resolution is poor. If you don't want badly nearsighted cave people with fuzzy vision, the pit organs will need to be larger than in snakes (larger than human eyes, in other words, if you want anywhere near the same precision), and/or possibly more than two of those sensory organs. Cultural interpretation of how your people might work with such organs is an exercise for the reader, but I suspect that blows to the face will be taken much more seriously (as posing a risk for blindness, even in the absence of active attempts at eye-gouging), probably with some societal taboo against touching another's face without permission, much less in the way of facial cosmetics, etc. I wish you the best of luck in figuring out other potential implications (read: further worldbuilding, possible points of interest from which stories can be launched, etc.). ]
[Question] [ In the setting I'm building now, then there's supposed to be a location where the natives had found three food staple crops within close proximity with one another, near a handful of rivers. Naturally, these natives would found one of the biggest economies in the world, and their lands would be *very* tactically advantageous to have, but I'm wondering how they could find so many crop species in such a small area. I'm wanting them to be in one of the temperate bands of their planet, and in a location whererivers and the sea are readily accessible, and that there would be some nearby mountains, so it's possible one of those mountains is a volcano that produces lots of ashes? To summarize, with these conditions, how would there be three different species of food staple crops? [Answer] ## Forest Gardening [Robert Hart](https://en.wikipedia.org/wiki/Robert_Hart_(horticulturist)) wanted to use the least amount of land to produce the largest amount of food possible. He pioneered a system where you can inter-crop fruit and vegetables into vertical layers which then grow together almost on top of one another. This is not used on an industrial level as it is people intensive to harvest. However, it is assumed this method of farming was a core [practice in jungles and monsoon prone regions](https://en.wikipedia.org/wiki/Forest_gardening#History). It will require a good amount of human intervention to fill all 7 layers but it is possible and was used in our own history. As far as how this would happen, it is possible that these plants are slowly transplanted by roaming animals between their own food staples and leave droppings with seeds as they pass by. [Answer] I'd like to address **"Naturally, these natives would found one of the biggest economies in the world..."**. There's a theory presented by Jared Diamond in *Guns, Germs, and Steel* which explains why the biggest economy in the world developed in Eurasia as opposed to the Americas. Agriculture originated in both hemispheres, but it happens to be the case that Eurasia is the best land mass for your native cultures to grow and expand east-to-west. Not only is the landmass larger, its mountain ranges tend to run east-west and therefore don't block people (or climates!) from extending along a line of latitude. And with early agriculture, it's a lot easier to take a few domesticated plants from one place and spread them to similar climates and latitudes east and west. The theory is that, even though the native Americans developed what many experts consider the most important crop in the world (corn maize), it would have been very hard for them to spread very far with it. It took a long time to develop new varieties that could survive at different latitudes with different growing seasons, and the American mountain ranges all being oriented north-south would have blocked migration and trade to the east and west. Now it's obviously a [just-so story](https://en.wikipedia.org/wiki/Just-so_story), an unverifiable hypothesis that can never be proven, but it does make a lot of sense to me. If you want your natives to found the greatest agricultural economy in the world, you need to consider not only where they find the crop species, but how they can spread them. If they're hemmed in by mountains or deserts, they're going to be limited. [Answer] For another example, there's the "Three Sisters" - corn (maize), beans, and squash - of the Iroquois and other Indian tribes of northeastern North America: <https://en.wikipedia.org/wiki/Three_Sisters_(agriculture)> Of course those plants did not originate there, but were imported from elsewhere. But that's really the norm: a useful food species will be rapidly exported to any suitable climate, once there is contact between them. Consider how quickly New World food crops like corn, potatos, and peppers (to name just three) were introduced into Europe. [Answer] **This is actually far easier than it seems.** The fertile crescent (a rather small patch of land centered around two close rivers) is the origin of 8 major crops, Emmer and einkorn wheat, barley, peas, chickpeas, lentils, vetch, and flax (which is fiber and food) and at least 4 major forms of livestock, goats, sheep, cattle and pigs, as well figs and several other possibles. This is not unique, it appears many places where agriculture originated (such as southern asia and central china) involved many local species being domesticated as time progresses. What all these places appear to share in common is many different climates/environments (mountains, valleys, forest, grassland) packed together adjacent to large rivers surrounded by large flood plains. This combined with great access to larger land masses seems to encourage both self-pollinating R strategist plants (which most of our crops are), and flexibility in diet, habitat, and mating for animals (which again is common to all domesticated livestock). this is not to say this is the only place they can evolve but these conditions encourage many species to have these adaptations. The current hypothesis/understanding is these conditions produce lots of local variation and a climate that shifts around easily yet still has high fertility, this discourages specialization and encouraging more flexibility and R strategy. They are also the sources of high yield grains which most major forms of agriculture are based on. so basically you need a large temperate floodplain bordered by mountains and desert, ideally attached to large continents for biodiversity. [Answer] You can have different environments in close proximity. Flood plains for rice, dry sandy soils for corn, clay-rich soils for beans, roots or cabbage. [Answer] If the problem is the lack of space, there is no real problem. Beside the idea of frost gardens there are othere possibilities. One way ist a crater bed. In German it is "Kraterbeet", but I could not find the right translation. Basicly you dig a large hole with a diametere of 3-5 meters. On the bottom is a dry zone, where you can plant crops that need much heat and less water. Then you plant on the walls the crops like beans, peas and so on. If raise the borders a little, all the corps are perfectly protected against the wind and storm. We tried this version and version where plant the crops on an artificial hill. Both works great with right crops. Farming in layers safes a lot of space, if you do not have to harvest with machines. [Answer] Plant crops that benefit from each other. E.g. beans using the stalks of maize as an aid to grow, while the beans provide the maize plant with [nitrogen](https://en.wikipedia.org/wiki/Nitrogen_fixation). ]
[Question] [ The selected answer on [this question](https://worldbuilding.stackexchange.com/questions/96984/whats-the-biggest-reasonable-natural-planet-or-moon-with-earth-like-surface-gra) provides an extremely good, and detailed, description of what is generally accepted to be the main (only?) way a terrestrial planet can form, i.e. through accretion of the gaseous disk around a forming star. My question is: Assuming that some discovery is made that concludes that this accretion process is false (this 'hand-waved' discovery is for the sake of argument, and it need not have any other bearing on our understanding of physics beyond this unique aspect of planet formation, though it can have other repercussions on known physics if it helps generate an answer), no planets, ever, anywhere in our known universe, were created using this accretion method, what is (are?) the next most likely method(s?) of planetary creation? Best answers will use a minimum of change to known physics whenever possible, and those changes need not be described or explained. I'm interested mainly in identifying the process itself, rather than why one process doesn't work and a new one does, I just want to know what the new process is. In other words, hand-waving known physics is allowed, but should be avoided as much as possible. Answers do not need to consider habitability of planets, except to the extent that we know of at least 1 (Earth) in the universe that ended up habitable due to this planetary formation process. Likewise, answers should not be limited to a process that obviously excludes the possible formation of any planet that we know to have formed in reality (don't describe a process that can only account for gas giants, but cannot produce terrestrials, or vice versa). [Answer] **Gravity is not "generated" by mass, instead mass gathers in gravity wells.** This is from wikipedia: > > A gravity well or gravitational well is a conceptual model of the gravitational field surrounding a body in space – the more massive the body, the deeper and more extensive the gravity well associated with it. > > > But what if scientists "found out" that the gravitational field is just there and matter just accumulates in the "dips" the same way rainwater forms puddles and lakes. Stars form where the gravity well is deep and planets form where the well is shallower, but it can only accumulate matter until it "reaches the well's rim" and then the overflow will go to different dips. (And where there isn't enough surrounding matter, we get those unexplained gravitational effects which scientists today call "dark matter".) I'm not sure this answers the whole question. For example, I have no idea how scientists would go about discovering this or disproving the accretion model. Or even if it would actually disprove it and not just exist alongside it. And I definitely don't know enough physics to tell you how big a handwave you'd need to create this theory. [Answer] We can go with an old disproven explanation that I found in an outdated science textbook I saw in high school: **Star Farts** > > During star formation, as the star's spin increases, it throws off > matter for its equator in bursts. The heavier elements don't travel > as far and form the inner rocky planets. The lighter elements travel > farther, forming the gas giants. > > > *(quote block to indicate that this thought does not come from me)* This same textbook said that Jupiter had only four moons. The sad thing is that they were still teaching the non-AP science class with that book. No wonder why there are flat Earthers with that kind of teaching. [Answer] # Gravitational instabilities There's actually a second idea for planet formation that's been around for some time (see [Kuiper 1951](http://adsabs.harvard.edu/abs/1951PNAS...37....1K)). It requires the nebula hypothesis, like accretion, but it's a top-down process, not a bottom-up one, involving the fragmentation of accretion disks around young stars to form giant planets. Protoplanetary disks can be [unstable under specific conditions](https://en.wikipedia.org/wiki/Toomre%27s_stability_criterion). In certain regions of overdensities inside a disk, clouds of gas may fragment into gaseous protoplanets, soon to evolve to become gas giants. The timescales of formation via this method are much shorter timescales than those required by the accretion hypothesis by an order of magnitude or so - tens or hundreds of thousands of years, Fragmentation would likely happen farther out in a protoplanetary disk ([Boss 1997](http://adsabs.harvard.edu/abs/1997Sci...276.1836B), and volatiles like ice would form part of the core. The hotter inner portions have been pretty firmly ruled out as potential sites. Current views hold that fragmentation is certainly a possibility, and may even account for the formation of planets with large semi-major axes (including, I believe, the system around [HR 8799](https://en.wikipedia.org/wiki/HR_8799), but it is unlikely that it contributes much to the general exoplanet population. Nonetheless, it requires no changes to the laws of physics. # Carbon planets and binary accretion Another set of methods involve interactions between a star and a companion object, where the star accretes much of the companion's outer layers, leaving a remnant that may appear to be a gas giant or a carbon planet, depending on the precise mechanism and the companion's original form: * [**EF Eridani B**](https://en.wikipedia.org/wiki/EF_Eridani#EF_Eridani_B) may be a star that had much of its outer layers siphoned off by its companion star, leaving an object that might be about as massive as a massive giant planet, but isn't a brown dwarf. * [**PSR J1719-1438 b**](https://en.wikipedia.org/wiki/PSR_J1719-1438_b), the "diamond planet", may be a very low-mass white dwarf that was mostly accreted by its companion (see [Bailes et al. 2011](http://adsabs.harvard.edu/abs/2011Sci...333.1717B)), leaving a dense object that would appear to be a carbon planet - terrestrial, but far from habitable. These processes can form either terrestrial or giant planets - an advantage the instability model doesn't have. Another upside is that we have solid candidates for "planets" that formed this way. However, these pathways aren't conducive to forming habitable worlds (although I noticed you didn't require habitability). ]
[Question] [ I am Kaine!! God king of the Wraith-men exiles. I am busy defending against the Sun Empire's holy war, led by the usurpers own son Leon the Holy Fury. The last battle was... a bit sporting, Leon charged through my ranks in hopes of cutting me down. We exchange blows, he made me lightly bleed I took his eye; it seems I was somehow on the worse side of the blow (my blood has giving hope to his men, they now think I can be killed) but not all the news is bad. My brother Carrion the Black Hand has not only successfully beaten The Golden Fleet and burned White Hearth to the ground, but added most of the fleets vessels to his own ranks (with the help of some War Whales link down below) My nephew Ivan thinks that my own army is also lacking in War-beasts so he has reinforced me with the Vargr clan and their war-hounds. I have not lead dogs into war before or how to use them effectively. so I will now hold a war counsel. Now my advisers I ask you: **What would be the best way to use these War-Hounds in the coming battle?** **Info** The Vargr clan only have 60 fighters/handlers but have over 250 war-hounds. I have to give them some of the dead just to feed them; the Skin Takers are not too pleased with this. The War-Hounds numbers consist of only medieval era dog breeds (huskies and Mastiffs ect) The Vargr men themselves are master bowmen and the art of stealth but not the best in close combat (they make up for that with their War-Hounds). They control the dogs with whistles and if need be horns, they can pull of advanced formations with the dogs even at a distance. To avoid friendly fire the Vargr men ask all my men to wear a certain herb on them, so the dogs can tell friend from foe (would love to know how you would avoid this in real life). The War-Hounds have two sets of armour thanks to the smiths of Iron Port, a leather one and a iron-plate one use them well to fit our needs The enemy army has made camp in an open field just outside of the woods they outnumber us three to one, but only the Holy Orders are elite, most are regular soldiers. The solders fear us... a lot; the Paladins on the other hand will fight to the death and may rally the troops I will just point out that there is no magic involved. **The tech level is high medieval 1400 century, steel plates are a thing but gun powder is not on the scene...yet** For more info about Kaine see also:[War Whales use in Naval Warfare](https://worldbuilding.stackexchange.com/questions/123148/war-whales-use-in-naval-warfare) and [Why Would an Enemy Army Retreat if they Will Die Anyway](https://worldbuilding.stackexchange.com/questions/121476/why-would-an-enemy-army-retreat-if-they-will-die-anyway) [Answer] **Attack the enemy supply lines:** Dogs will not do much against organized units, but an ambush executed by hounds, the Vagr and our own troops will deal with that problem. The dogs should attempt to get in the middle of the enemy soldiers, the Vagr should lay down supporting fire and weaken the line for the war dogs and our slower troops can charge the disorganized enemy lines to finsh them off. The dogs could also target horse cavalry units with greater efficiency than infantry could. **Line breakers/disruptors** Mayhaps we could use the dogs in combination with skirmishers to create gaps into the enemy main battleline. Even if only small ones as one section moving up slower than another. Skirmishers could throw javelins and dogs could harass the lesser armored troops. Dogs could easily retreat back behind our own lines if need be. **Hunting enemy scouts/Sentry duty** Not a glorious part of battle, but denying our enemy intelligence could greatly increase our army's odds of succes. Similary preventing enemy raids will help the moral of our troops. **Sneak attack** If our dogs somehow manage to find a way into the enemy camp they could cause a lot of ruckus. To increase their vandalizing efforts we could equip them with torches. Dogs are faster and smaller than humans. Let's see how easy disorganized defenders can prevent our dogs from setting aflame their camp. [Answer] If it please you my lord, I would send these masters of stealth and beast to **raid the enemy camps in the night**. The dogs would do well to attack the foe in their sleep, frightening their cavalry and reducing their number. Once the element of surprise is lost, they may withdraw into the woods, hopefully none the worse for the raid. With their men sleep-deprived and demoralized by the vicious attack, we should best them easily in the field. I do not know if this would be too dishonorable to contemplate, but is the Usurper worthy of honorable combat? [Answer] My lord, if you allow a word, 250 war hounds are not gonna survive long in a battlefield. Yes, they are terrifying, and yes, I'm sure those Vagr have trained them to be obedient and letal, but how do they fare against steel? Can their teeth pierce mail? Are they able enough to jump at the enemy's throath, while they swing swords at them? And when they die, how long does it take for a new dog to be trained and fill in the ranks? As other generals of your army suggested, I'd keep the dog for suprise attacks and night raids. Also, they could be used to hunt down parties who detach from the main body of the enemy army, or carry swift pokes on the sides. ## But my twist of the matter is this: use those dogs for psychological warfare. Those regular soldiers that you mentioned interest me. The paladins won't be easily scared, but screw those - the main body of the enemy forces will be made by soldiers, yes, but not all soldiers by profession or vow. Some will be peasants, some will be farmers, all will be longing from home in some place far from the gruesome fingers of war. Let the dog strike at night, then make them howl, or bark, as angrily as they can. After all, few things stroke fear in the heart of men like unseen beasts howling in the dark. Get a few nights of this, and when the final day of the field battle come, have a part of your war dogs (let's say, 100) attack the rear of the soldiers. **The others should be left as reserve, some place where they cannot be seen, but they can be heard**. If the attack-body of dogs strikes fast enough, the enemy won't be able to kill most of it, and any dogs that fall can be replaced by a new, eager one from the reserve. Meanwhile, the reserve should continue making as much noise as possible. The enemy soldiers will fight constantly with their ears filled of the war hounds angry barking. To those poor fellows, it will seem that those dogs are being vomited by the seven hells themselves. [Answer] I usually skip questions like this after a couple of paragraphs, but I read yours all the way through. Very creative. I doff my spangenhelm to you. Someone mentioned that these are hunting dogs, but I don't see that in your description. (As pointed out, I see that now in one of the rolled-up comments. These are some pretty well-trained hunting dogs! Me wonders what they're hunting to require this level of training...) I also use war dogs in my milieus as far back as first edition AD&D and, contrary to what many of the other answers have indicated, I have found them to be very effective. They're the cheapest warriors you can hire and the easiest to train! And if your PCs and NPCs handle them properly you won't lose many of them. Attack dogs are both a terror weapon, and an extra attack for your player or NPC. As a terror weapon, while they tend to be dispatched/vanquished fairly easily one-on-one, their effective armour class makes them difficult to get in the hit you need to actually do damage. They don't do a lot of damage on their own, but they latch on or can "knock prone" fairly easily. One-on-one they're not good. If you send in your dog against a defending PC and just stand back to watch you'll likely lose the dog. Send in the dog then get in there yourself! When the dog latches on to your opponent he will take a dex penalty even if he isn't knocked to the ground, then you get in there and give your opponent something else to think about. PCs usually yell "Run Away!" under an organized/experienced dog attack. An opponent under your dog attack must contend with the dog *and* your attack. Not only are you getting an attack against him every round, but so is your dog. The beauty about this is that there is no logical strategy to deal with it! If he attacks you then he suffers a dex penalty because of the dog. If he attacks the dog he still has to absorb your attack -- and you're probably going to hit him due to the effects of the dog attack! I've had experienced players literally panic under a dog attack. They don't know what to do. You say that you're outnumbered, but a well-run attack using dogs with a little luck could force a morale check in your opponents. In my worlds it also turns out that any war dogs in the group are usually "handled" by one character who is usually a proficient combat character, although my player groups have hired non-combatant war dog-handlers specifically for their support. That's not how I had envisioned it, but that's just the way it turned out. Your Vargr group seems to be a cross between the two. Clearly the dogs and handlers will have to enter combat as ancillary troops -- they go in supporting your main force: one or two dogs attack an opponent which is then engaged by one of your primary combat troops. Dogs have two traits which affect combat: loyalty and training. Dogs can be a bit of a wild-card during combat, sometimes biting their owner accidentally, but they will tend attack the target to which they've been assigned and will tend to stay on that target even when things get hairy. In fact, even after you've killed your opponent the dog will tend to continue to attack the body until called off. Loyalty can actually be a bit of a problem. If you own and have actually trained the dog, that dog will tend to switch his attention from what he is attacking to whatever it is *you're* attacking! You can let the dog go then run into another room to do combat with something else, but if the dog sees you fighting in another direction he tends to switch his focus to the target you've engaged. Because of his loyalty, you can't trust the dog to stay on a target which is different from yours. I would suggest that you avoid plate on a dog. Yes the dog is weak, but he already has a pretty good armour class by virtue of size and speed. We've used leather, ring, and occasionally scale, but I don't believe plate is realistically workable. He loses too much dexterity, his attacks become far less effective, and he tires too quickly. (Not to mention that you're carrying around a set of plate for your dog!) Another suggestion: we know that dogs have been used for martial purposes way back through even pre-history. They tend to take on specific roles: combat, sentry, runner. A runner will carry communications but will not fight. A sentry or "guard dog" is great at watching an area, but will not carry communications reliably and is also generally not as good in battle. Dogs used in battle are far more aggressive than sentry dogs, but they can still be used in that role. I cobble up an intelligence roll for dogs to allow them to learn multiple roles, but multirole dogs are a bit of a rarity -- you can't have a whole lot of Hooches, Jerry Lees, and Lassies running around all over the place! Most of them are like Marley, or at best Beethoven! [;D So, my suggestion is that while the Vargr seem to be handling about 4 dogs each, some of those will be sentry-role dogs which will be used to patrol the perimeter. Some very few (1 in 10 or whatever) will be strictly for communication, or you may want to leave that level of complication out of the mix altogether for now. Oh -- another suggestion! I don't think the herb is really necessary. Unless the dog is actually attacked from another direction the dog tends to stay on his target when loosed, even when something else gets in the way. I know what you're thinking, but if you just let these dogs loose on the battlefield today you might just as well send the Vargr home tomorrow because there won't be any dogs left for them to handle. Pair the Vargr up with one (or even four!) of your regular combat troops and send them out onto the battlefield (or bushwack or whatever) in teams. I mean, the handler and his dogs are already a team, so adding an extra pair of elbows shouldn't complicate things that much. Those are my thoughts and experiences and I hope you find them useful. Good luck with it. [Answer] I think the most effective time to release the hounds is when you're assaulting a fortress and you've just broken an opening in the doors or walls, or you've just let down the ramp of your siege tower onto the walls. In midieval warfare, bottlenecks such as these were chaotic and bloody, but had to be pushed through. Usually the most heavily armored and craziest men were chosen to be the first through the hole (charging the breach). But your dogs would have several advantages. While men have to crash through the breach, as in the picture, the dogs could nimbly dart through small gaps between the defenders (even through their legs!) and then come around from behind. Once through they can cause chaos. And they could sprint through the breach fast enough that you could pour many of them in quickly. While the defenders have the dogs either nipping at their ankles or tackling and mauling them, you can send men through the breach to reinforce. Even if the dogs can't kill the defenders, if they can just distract them by biting their ankles, they'll give enough time for a significant party of attackers to get through the choke-point and form up on the inside. [![enter image description here](https://i.stack.imgur.com/ivCjH.jpg)](https://i.stack.imgur.com/ivCjH.jpg) ]
[Question] [ This is in regards to the Tyranny of Rocket Fuel. Summed up: Heavier ships need more fuel which makes them heavier, etc. You end up with diminishing returns. This is compounded by higher gravity - Everything is heavier in the first place. There's an article that claims that, beyond 1.5g, conventional rockets become effectively unusable. But what if we take that the other direction? Lower gravity lowers the weight, which lowers the fuel required, etc. So, you get more "Efficient" rockets. Now, to my question. Say we have a civilization, at the beginning of rocketry. They're largely identical to humans, except for **one** key difference: Their planet is smaller and has gravity that is 1/6 that of Earth. **Would that civilization's rocketry/spaceflight advance at a quicker pace than we have seen in our own history?** Things to be ignored: * Differences in the planet **other** than what would be caused by the gravity and size. Assume the same resources, oceans, atmospheric pressure at sea level, etc. * Differences between this hypothetical species and humans. Just assume they're humans for terms of mass, food requirements, etc. [Answer] I'd say yes because: As soon as the human scientific level reaches a point where a certain technology becomes usable governments, companies and indiviuals will begin to tinker with it. Let's compare the automotive industry with the space industry. In 1886 Carl Benz patented his 'Benz Patent-Motorwagen' - the first car. He built it with little assistance and his wife was able to [drive the third version](https://en.wikipedia.org/wiki/Bertha_Benz_Memorial_Route) through germany in 1888. Let's jump forward 50 years to 1936. The automobile is a common sight in our society. (Rich) individuals use it, the government uses it as well as companies. There are many competetive companies that produce them. Many big companies and brands we see today (Mercedes, Audi, Opel, Toyota e.g.) started as small businesses that grew due to their success. In 1957 the Sovjet Union launched the first satellite. This was no individual task. Thousands of people and a whole megacountry were behind the development of the R-7. The USA quickly caught up and for a long time space exploration was a matter of this two countries. If we jump 50 years forward (2007) again we see a picture that's quite different from the car's 'success story'. Some big companies and government owned space agencies still do all the contracts. Even very rich individuals can't get to space, even if theoretically they'd have the money simply because of the little capacity of manned spaceships we have. The whole individual and small business tinkering level that made the automotive industry so fast growing is completely missing because you need a very big amount of money, material and workforce to even enter, let alone succeed in this business. If you imagine you could make a rocket that could travel to space and back about as big as a truck, you'd need a lot less material and people. A small team could build one. You'd need weaker rocket motors with less fuel which would mean you could do it with less expensive materials and bigger quality tolerances in the parts you use. So I think yes, easier access to space would mean that we would advance much faster in the technology we use. [Answer] the simple answer is yes. It will be easier for rockets to achieve either orbital or escape velocity from the lower-gravity Earthlike planet. By comparison with planet Earth with an escape velocity of 11.2 km/s the hypothetical planet will have an escape velocity of approximately 2 km/s. Chemical rockets have exhaust velocities of 4 km/s and this means rockets launched from Earth into space will have large mass ratios. Mass ratio is the ratio of the mass of fuel to the payload. That's a simplified version of the concept, but it should suffice. On a planet where the escape velocity is actually lower than the exhaust velocity of a chemical rocket the mass ratios of space vehicles will be much lower again. This is due, mainly, to the compounding factor of burning fuel to lift more fuel that needs to be burned to achieve even higher velocities. Lower gravity will ensure not only much less fuel needs to be burned, but the additional amount to reach those even higher velocities, especially velocity above exhaust velocity itself. The net result is smaller, also less dangerous and difficult, rockets can be launched into space with bigger payloads. Therefore, the technological and economic barriers for working space vehicles propelled by chemical rocket engines will be considerably less than on planet Earth. In conclusion, yes spaceflight can be achieved earlier. provided other push factors are in play (but they're not technical factors involving rocketry). [Answer] No, simply because there really isn't that much room to do things quicker than they actually were done. It takes a certain level of mechanical sophistication - accurate machine tools, materials, &c - to build a working rocket engine. That was reached in WWII, with the German V2 (1944). Going from that V2 to manned space flight took only 17 years (1961), and from there it was only another 8 years to Apollo 11. So how do you get much faster than that? After that, the reasons for the pace of space flight become as much political and economic as technical. Absent something like the US-USSR "Space Race", governments aren't willing to devote that much effort to it, and private entities don't see much potential for a quick return on investment. There just isn't all that much up there, really :-( Now for the practical (communications & weather satellites) and scientific space missions, the cost of launching the spacecraft is only a small part of the cost. A launch might cost (roughly) 50-250 million. (All amounts US dollars.) Building a communications or weather satellite might cost from 250 million <https://www.globalcomsatphone.com/hughesnet/satellite/costs.html> to 11 billion for the 4 GOES-R weather satellites: <https://arstechnica.com/science/2016/11/americas-new-super-expensive-weather-satellite-launches-saturday/> For a scientific mission, a billion dollars is relatively cheap, e.g. Cassini 3.26 billion, New Horizons 700 million, the Webb Telescope 8.8 billion and climbing.... [Answer] On a planet where gravity at surface level is 1.6m/s^2, launching yourself into space isn't the problem. Assuming that the planet's radius is about 1/10th and it's mass is about 0.16% of Earth's (which makes the planet slightly denser than Earth but makes the calculations easier), you can reach orbit at around 1km/s and escape from orbit at about 1.5km/s. You can realistically reach 1km/s with a black powder rocket, a technology that was invented circa the 12th century on Earth. With motivation (and it's likely that people would realise pretty quickly that what goes up often takes a very long time to come back down again, and therefore start attempting to send larger and larger objects up faster and faster, just to see what happens to them), it could well have been possible to launch a primitive orbital vehicle by, say, the 15th century. The problem that a 15th century space explorer would have is that there's not very much atmosphere up there. Anything alive that they sent up would die. Building a pressure vessel that can withstand vacuum is actually a harder problem. Leonardo Da Vinci sketched a design for one at right about the right time, but like many of his ideas the materials were not available to actually make it. The earliest known actual pressure vessels were built in the 18th century, thanks to advances in metallurgy and manufacturing techniques. So, without changing history of the developments of the various technologies you'd need, the earliest space exploration could realistically begin on a low-gravity Earth would be the 18th century. Significantly earlier than it actually did occur, but not as soon as you might expect at first glance. [Answer] Yes, but not dramatically faster. World with 1/6 would be similar to the Moon, where velocity to reach an orbit is 1.68 km/s and escape velocity is 2.4 km/s (for Earth, those numbers are 7.9 and 11.2 km/s respectively). If this is not a Moon-sized world, but a hypothetical low-density planet with the exact size as the Earth, those numbers will be 3.27 and 4.6 km/s (but average density comes up as fluffy 0.938 g/cm3). As the result, launching satellites and even interplanetary missions would be be considerably easier. A simple one-stage rocket can do the job. For a Moon-world, its inhabitants can even use Jules Verne-style [space cannons](https://en.wikipedia.org/wiki/From_the_Earth_to_the_Moon) to send out probes. All in all, space can be reached with XIX century technology and even earlier if they are determined to do so. However, the early probes can be only unmanned and not quite sophisticated ones. A number of advances in electricity, radio and material science will be needed to launch a man into space (and bring him or her back alive). Manned mission would have to wait until mid-XX level. However, some daredevils may try it earlier, and suborbital uncontrolled flights are still possible at XIX century tech level. After space flight details are worked out (circa 1970 tech level in Earth), there would be a big potential for quick development unseen here on Earth. Sending probes to space would be cheap, it would not require an expensive state-sponsored program (though rocket science would not get much easier). In addition, the concept of [Spaceplane](https://en.wikipedia.org/wiki/Spaceplane) would be much more viable in low gravity. Their Space Shuttles may be able to launch horizontally, use wings to climb to stratosphere and then go higher into the orbit. Lower orbital speeds would make reentry easier as well. [Answer] I'd say yes, but less than you might expect. Rockets in one form or another have been around since at least the $13^{th}$ century in China but it took a long time for anyone to even think about using them beyond line of sight. The main thrust for developing rocketry in the modern era was political; first for their shock value in over the horizon warfare and later for the propaganda and ideological value of the space race. So while lower gravity will make pushing into space easier once the decision to go that road has been made that doesn't of a necessity mean that the decisions behind the space race would *be made*, earlier or at all. Further to that the *other* technologies that you need to go to space aren't any easier to come by because the gravity is lower so their development will still be a decisive factor in your progress. ]
[Question] [ Humans with a level of technology roughly equal to the present day, not more than a decade or two more advanced (e.g. they might have slightly more efficient rockets, or a more miniaturized comm system, but no stargates, warp drive, or lightsabers), found a colony on the surface of Mars. Assume a somewhat stereotypical settlement infrastructure with landing pad, living habitat, hydroponic farm, research lab, etc., for anywhere from a dozen to a few dozen colonists. For some reason (because plot), the colony is abandoned (all of the people leave or die) while it is in working condition, and the colony site is then not visited by any life form for an arbitrary length of time (e.g. hundreds or even thousands of years). How long would it take for the colony to become an unidentifiable, or barely identifiable, pile of rubble? We have a lot of archaeological data on how long stuff lasts *on Earth* before being effectively returned to nature, but would these measurements apply on Mars? As Mars has an active weather system (unlike the Moon), I expect that there will be significant erosion effects, but I doubt that the rate would be the same as on Earth. Would the colony last a hundred years? A thousand? Ten thousand? A million? A hundred million? For the purposes of this question, "unidentifiable" means that the physical infrastructure has effectively returned to nature. Some remnants (e.g. scraps of metal, pieces of plastic, a screw or bolt here and there) can remain that testify to prior inhabitation of or at least visits to the area, but determining what those parts were *from* (e.g. telling that this aluminum board was from a Standard 12 Person Habitat (TM) manufactured by SpaceCo in 2022 as opposed to just knowing that it was probably built by humans or possibly another civilization at some point in time) would require at least a *significant* archaeological expedition and research project, not a casual glance. Feel free to make any reasonable assumptions (if any) necessary to answer or simplify the problem by comparison with similar components whose properties are well-known (e.g. "If the colony was more or less a bunch of Apollo capsules welded together, based on what we know of their construction, the answer would be....") [Answer] It would last forever (longer than humans anyway) although get covered in dust. Mars has a thin atmosphere, so weather erosion would be negligible and it doesn't rain. Mars doesn't have microorganisms that we know of that will break things down. Mars is geographically stable it doesn't have earthquakes, volcanoes continental drift etc,. nor does it have things like weeds or vines that rip concrete and stone apart on earth. Even gravity is much weaker so stress caused by that is nothing compared to Earth. So you're missing almost anything that would cause damage on Mars. Judging by some comments too many people saw a martian storm in a movie and thought it was based on science instead of entertainment. I enjoyed the movie as well, but in reality the atmosphere is so thin a martian storm would have trouble blowing a piece of paper over. Simple logic, water moving at 10 mile an hour will knock you off your feet and carry you with it, air moving at ten miles an hour is a gentle breeze, martian atmosphere moving at 10 miles an hour you wouldn't even notice. It's all about density. [Answer] It depends on how the colony is constructed. If the structures were build of aluminum, I would expect it to corrode, gradually being oxidized reaction with the CO2 in the atmosphere. The wind-blown sand would expose fresh aluminum surfaces, which would preeferentially bond with the Oxygen, leaving free Carbon. But, based on some current Mars exploration thoughts (such as the Mars 1 mission), the structures brought from Earth would be temporary, to be replaced with new, larger structures fabricated with local meterials. One fabrication technique would be to 3D print a concrete-like material derived from Martian rock, dust, and water. This material should not have a tendency to oxidize since the minerals would already be in an equilibrium condition with the atmosphere. I don't know how to gauge the wear resistance to wind-blown dust, but I would be better than aluminum sheet but not nearly as good as rock. The power infrastructure could be a different story. Solar panels would be subject to dust erosion and scratching. A radioisotope thermal generator would degrade as the heat source decayed. I'm going to guess that the station could be restored to operation for a couple of hundred years, recognizable as an active colony for 10,000 years, and identifiable as an intelligence created artifact for 100,000 years. I don't have any killer arguments, but it seems reasonable and could support many stories. If the colony were built underground, it should be better preserved, but would be harder to find. We don't have active plate tectonics on Mars, so Mars-quakes shouldn't be much of a threat. The entrances would be subject to the same degradation and erosion effects. I looked for a simple source of meteorite impacts on Mars to estimate the probability of an impact obliterating the colony, but I ran out of time. I found that the impact rate on mars was estimated to be, at most, twice the lunar impact rate [paper discussing the estimation methodology](http://www.planetary.brown.edu/planetary/geo287/PhobosDeimos/papers/Ivanov%20(2001)%20Mars-Moon%20cratering%20Rate%20ratios%20estimates.pdf), with the corresponding craters being smaller due to Mars gravity. [Answer] It is true that there is no biology, rain rust or oxidization on Mars. But there is wind on mars,and it is moving the dust: <https://www.space.com/39776-mars-dust-burying-phoenix-lander-photos.html> <https://en.wikipedia.org/wiki/Cleaning_event> Dust and wind mean abrasion, and it will wear everything down eventually. It will take a long time, longer than on earth. 100's of years for structural elements. Many of the walls will be thin sheets though, and those will be gone in 100 years tops,leaving the stronger skeleton of the building standing. I also wonder if moving sands will bury the structures before they weather them away. If you want remains of the colony to last longer, have colonists build stone buildings, or line their structures with stone. ]
[Question] [ The Leech Dragon, so named for its round, leech-like mouth, is by far one of the creepiest and most vicious dragons. Part of the reason for its infamy is its ability to exhale toxic and very flammable clouds of methane gas. These relatively small dragons, (about 5-6 feet long and very thin), congregate together and can rapidly turn enclosed or poorly ventilated areas into lethal gas chambers. In addition, these dragons can create sparks by rubbing their teeth or scales together, which ignites their methane breath attack and creates a large and very fast moving fireball. So here is my question. **Where does the dragon get the methane and how does it release it?** Alternatively is there some other gas that would work better/be easier to obtain? [Answer] ### Your dragons are vegetarians and have a lot of different stomachs - just like cattle To cite from the Wikipedia article on [cattle](https://en.wikipedia.org/wiki/Cattle) (emphasis mine): > > **Gut flora in cattle include methanogens that produce methane as a byproduct of enteric fermentation, which cattle belch out.** The same volume of atmospheric methane has a higher global warming potential than atmospheric carbon dioxide. **Methane belching from cattle can be reduced with genetic selection, immunization, rumen defaunation, diet modification and grazing management, among others.** > > > You need the same gut flora as in cattle and then you select those individual dragons that produce a lot of methane to produce offspring. Evolution might for example favour them because their gut flora is better suited to their environment - or maybe dragons found methane [sexy](https://en.wikipedia.org/wiki/Peafowl#Evolution_and_sexual_selection) because it's harder to hide from your prey if it can smell you for miles. In the end you have a very high amount of methane that gets produced. Especially if you think about the size of a dragon. Dragons are *huge* - there is a lot of room for stuff to produce methane. Methane is also [lighter than air](https://en.wikipedia.org/wiki/Lighter_than_air), which can be used as a pseudo-scientific way to help explaining why they are able to fly (the square cube law would still get in the way, but we are talking about dragons and as everyone knows dragons don't care about physics - physics is too scared of them). [Answer] /Alternatively is there some other gas that would work better/be easier to obtain?/ The problem with methane is that it is a gas at all biologically relevant temperatures and pressures. That means it occupies a large volume and is hard to store. Also it is difficult to project a cloud of gas - the large volume and low mass means that air resistance slows it down a lot. The dragons would be largely within their own gas cloud and would have to deal with the "whoever smelt it dealt it" principle. A better gas would be something which could be a liquid at biological temperatures and pressures - it could be stored compactly in the animal and projected as a dense flaming liquid that rapidly turns into a gas heat. Consider butane - it is a gas at STP but a liquid at 2.6 atmospheres which can be achieved in a disposable lighter. Pentane has one more carbon than butane and boils to a gas at 36C, so could be kept at atmospheric pressure in a cool animal. Vertebrates do not make alkanes. Better yet would be a volatile flammable liquid which actually is produced in animals. I propose [**acetone.**](https://en.wikipedia.org/wiki/Acetone). It is a liquid with a low vapor pressure. A Bronx cheer breath weapon of acetone droplets would turn into a sweet cloud of flame. Enthalpy of combustion is double that of methane (though lower than propane). Acetone is in animals, produced by ketogenic fat metabolism - even humans normally make small quantities of acetone. Plus it has that great smell of nail polish remover. ]
[Question] [ There is a planet (let's call it Bob) where an ancient and powerful race once lived. They built giant gravity lifts to help move massive amounts of water high up into the atmosphere for who knows what (maybe they liked heavy rain? sadly they didn't leave any notes). They are long gone now, but their gravity lifts are still running (well one of them is at least). It is constantly lifting a kilometer sized column of sea water up to the edge of space at which point it rains back down over a nearby land mass (*the current inhabitants think the sea god is fighting the sun god but that's another story...*) **Would such a system be enough to keep the island constantly shrouded in thick, dark rain clouds?** The gravity lift is in the shallows just offshore and the island is a couple hundred kilometers across (I'm guessing the rain would be more intense on the gravity lift side). The gravity lift runs constantly thanks to some unknown power source and has been pumping millions of tonnes of sea water every day for millions of years and will probably continue to so for a long, *long time.* I imagine it would look a lot like this, only with a much, much bigger column of water and with the dark clouds blotting out the sun for hundreds of kilometers in all directions. [![giant waterspout](https://i.stack.imgur.com/32cjC.jpg)](https://i.stack.imgur.com/32cjC.jpg) [Answer] # Unlikely You're not generating clouds like this, you're generating (salty) rain directly. Look at the [Angel Falls](http://www.wondermondo.com/Countries/SA/VEN/Bolivar/AngelFalls.htm) for the effect you're going to get. At the top it's a waterfall, but by the time the water is about 2/3 of the way down it's effectively falling as rain. You're going to have much the same effect over a much larger area, the rain will constantly fall, with a permanent rainbow in daylight, but you're unlikely to see clouds. [![Angel Falls](https://i.stack.imgur.com/jRggQ.jpg)](https://i.stack.imgur.com/jRggQ.jpg) [Answer] Edge of space. Call it 100 km about 60 miles. E = mgh Since we want to get to E/kg we'll drop the m. E= 10 \* 100,000 So it takes a million joules per kg to get up there. Now we drop it. Specific heat of water is 2,260 MJ/kg. Which is about 5 times the energy it takes to get to boiling. So, incoming water will be heated to boiling point by air friction, and somewhere between 1/4 and not quite a half will be evaporated. (Some of the heat will be transferred to air. ) Also, as it falls, Coriolis forces bend the column of falling water to the east. Water as it starts to fall from near vacuum will evaporate from the surface of the drops, chilling the remaining water, likely until it freezes. It's cold up there anyway. So you have a column of hail. So you end up with a plume of hot steamy air slanting down from the top of the lift to the east. The atmosphere on Earth thins by half every 18,000 feet. So 3/4 of the air friction will be generated in the last 36,000 feet. The upper part of the column will look like a white pillar curved to the east at the bottom, with almost razor like edges. Not much wind to push it around until you get to the top of the troposphere. At the bottom, the drops start to slow down, thaw, then heat up. They are boiling. But hot air rises, and water vapour anyway is less dense than air, so now the plume feathers upward. So the bottom of the column is the the source of high energy very strongly convecting very wet air. At this point my intuitive meteorology is gasping a bit, and much depends on how fast the water is being pumped out. If very slow, you may just end up with a permanent trail of cloud down wind. If fast, you may have a fixed location thunderstorm, with tornadoes. If really fast you might have a permanent hurricane. [Answer] # You will have rain, not clouds I didn't believe Separatrix's answer, but after investigating, I find out that he is right. The problem is that they are lifting sea water an the ocean is salty. The gravity lifts will be releasing a *lot* of salt with the water you are spraying into the atmosphere. First, some background physics; dense, low lying clouds of the type you are imagining are [stratus clouds](https://en.wikipedia.org/wiki/Stratus_cloud). Stratus clouds are composed of droplets in the 5-20 $\mu$m range, mostly (reference: [Miles et al, 2000](http://journals.ametsoc.org/doi/pdf/10.1175/1520-0469%282000%29057%3C0295%3ACDSDIL%3E2.0.CO%3B2)). Droplets of this size have sufficiently low weight to surface are ratio that they can be kept aloft as...clouds. If they get much larger, their weight becomes great enough that they fall as rain. In order for droplet to get larger, they must condense around [cloud condensation nuclei](https://en.wikipedia.org/wiki/Cloud_condensation_nuclei) (CCN). These are usually small aerosol compounds. This i the concept behind '[cloud seeding](https://en.wikipedia.org/wiki/Cloud_seeding)' to produce rain with a compound such as silver iodide. In any case, salt is an excellent CCN (reference: [King et al, 2012](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3462475/)). So you are pumping water and salt into the air, and as the water evaporates *a la* Angel Falls, the salt particles are freed to condense as crystals. As soon as the salt crystals reach critical a diameter of about 0.2 $\mu$m, they start to act as CCNs, and cloud droplets start to condense around them. # Conclusion By spraying salty seawater into the air, you provide the raw materials for clouds, but you are also 'cloud seeding' the clouds at the same time you create them. While there will certainly be some cloud formation, most of the water will condense around salt crystal particles and fall as rain. [Answer] **Regrettably, not necessarily** While clouds and rain most often go together, they don't always. I've been in rain showers under a cloudless sky. Basically, the drops form faster than the mist. The condition is called [Serein](https://en.wikipedia.org/wiki/Serein_(meteorology)). In this case, where water is being pumped artificially into the sky, I can easily imagine that not a single cloud would form. Unlike the process of evaporation, where water has yet to form into droplets, permitting clouds to form, you're kinda going straight to droplets. So, the real question is, what's happening at the top of the gravity lift? Is it simply a gyser? Then I think you're out of luck. Is there some kind of gigantic [atomizer](https://en.wikipedia.org/wiki/Atomization) that would reduce the water to a much finer component? If you can get the water to a fine enough state, then the answer to your question is a resounding yes. If you're just squirting water into the ionosphere or exosphere, then methinks it would just rain, no clouds. [Answer] **Probably not the effect you wanted** One key parameter that you need to consider carefully is the rate of water flow. Even with a 1 square km opening, if it’s just dribbling over the edge it’s not going to do much, but if it’s pumping out at 1 cubic km per second then that’s another story entirely. The effect depends heavy on this parameter. Assuming that the flow is very large, one of the first effects would be evaporating into the vacuum of space cooling the water and possibly freezing it or portions of it. Under equilibrium conditions the water would rapidly evaporate and disappear into space. But with huge volumes of moving water there would be no time to establish equilibrium so a large proportion of it would fall to earth. As the edge of space somewhere around 62 miles up, it will mean pumping an enormous amount of potential energy into the upper atmosphere. The pressure would be very low (continual evaporation of water will provide some pressure) and the water will rapidly accelerate into the lower atmosphere. As the air density increased in the lower levels of the atmosphere the water would be heated due to friction and most of it would evaporate, what was left would remain as fine warm salty droplets. If the flow rate were high enough then substatial amounts of salt water would eventualy reach ground level, but in order for this to happen the amount of moisture introduced into the atmosphere would be astronomical. Large inputs of energy and moisture combined with a lot of displaced air would probably generate massive storm systems in the area and the location might become quite unstable with violent electrical storms and hurricane strength winds and an ongoing basis. ]
[Question] [ I'm working on creating a species that favours small families for a number of reasons, and have no interest in 'breeding as much as possible'. As a consequence, their population size is small. But how small can a population be, without running (ever) into problems with genetic diversity? I'm interested in more than 'survivability'; the species' gene pool should not degenerate (some margin allowed). I'm looking for some well-founded answers or directions. Assume that genetics for this species works similar to that of humans, and that their gene pool is of good quality at the start. You can also assume that they choose partners wisely, but there is no designation of partners, so margin is necessary. They have good health care and low child mortality rates. Assume that at least 90% of the population reaches at least fertile age. Other 'rules': * Average number of children born is two (might be increased to three if that is necessary to sustain the population) * Species is monogamous * No genetic manipulation --- This question differs from the question [What is the minimum human population necessary for a sustainable colony?](https://worldbuilding.stackexchange.com/questions/3/what-is-the-minimum-human-population-necessary-for-a-sustainable-colony) because: * It is assumed (for a population of 80 / 160) that the population will mingle with a larger population after ten generations * The population of 350 still resulted in some genetic issues (of which some disastrous) This question differs from the question [How many humans do you need to maintain a population indefinitely?](https://worldbuilding.stackexchange.com/questions/82901/how-many-humans-do-you-need-to-maintain-a-population-indefinitely) because of the given context that everyone in the group is the genetic parent of exactly two children each with a different partner which is violating above assumptions. This question differs from the question [Minimum Population For a High Tech Society?](https://worldbuilding.stackexchange.com/questions/70880/minimum-population-for-a-high-tech-society) because it is not about genetic diversity, but the skills and intelligence needed to run a high tech society (which is possibly a follow-up question). Some other questions touch this topic, but they are (slightly) different in either the assumptions or the direction of the question. [Answer] I happen to work in population genetics with a focus on conservation. In the past I have worked in human genetics also (human populations were really small for most of the existence of our species). The general gist of the answers above are quite right. There is a rule in conservation genetics that says you need at the very leas an effective population size of ~50 to have a viable population. Do not confuse the technical term "Effective population size" with "Census size". Effective population size models assume a certain number of theoretical ideas, like e.g. random mating. There are several ways you can keep genetic diversity up: * The least inbreeding the better. Monogamy is actually better than random mating and way much better than "winner takes all". * Make sure that over generations people mate with distant individuals (even if from a small population). Mating with your sibling is not a great idea to maintain diversity * If you allow say, an immigrant per generation than you are probably safe. There are plenty of studies that, if a migrant (a single one!) enters the gene pool and has reproductive success, that is enough to maintain genetic diversity in very small populations. + Your population sex ratio (number of born males over born females) should approach 1 Note that if your world can tolerate minimal migration, than you are mostly sorted. [Answer] Well, first things first: If 90% of those born reach reproductive age *and have offspring of their own* (which is all that matters in the long term), and each pair has two offspring, then mathematically the species will be declining. Plugging 2÷0.9 into my calculator says you'll need at least about 2.23 births per pair *just to maintain a steady-state population* with a 90% reproductive rate, regardless of what happens to the remaining 10%. Let's round that to 2.25 and every fourth pair will need to have one additional offspring for a total of three (as 4\*0.25 = 1 and 3\*2 + 1\*(2+1) = 9). In this case, the most common number ([mode](https://en.wikipedia.org/wiki/Mode_(statistics))) of offspring per pair will be 2, with an average ([arithmetic mean](https://en.wikipedia.org/wiki/Average#Arithmetic_mean)) of **2.25. That's your *absolute minimum*** to ensure that the population doesn't decline simply from lack of reproduction. However, that leaves you with next to no margin at all for any unforeseen events. If anything happens, then you need more offspring elsewhere in the population that end up reproducing in order to compensate for the loss. If a mother dies in first childbirth, for example, and this causes the death of the offspring (not necessarily a given with good healthcare, but definitely a risk), then you need someone else to have *four* (or two to have three each) where ordinarily they would only need to have two offspring each. I would strongly suspect, but lack citations for backing that up, that if you start out with a healthy gene pool, genetic degredation over ten generations should be sufficiently small to not cause major issues in the short term. Researching breeding in some uncommon breeds of dog, where the [effective population size](https://en.wikipedia.org/wiki/Effective_population_size) especially within a country can be on the same order of magnitude as that which you are discussing, may provide some insights here. (While dogs are obtained across borders for the purposes of breeding, both as adults for a single or a few litters or as pups by breeders hoping the individual will turn out well, even e.g. within the EU there are significant obstacles for this, causing such exchange of genetic material to happen less frequently than it could and consequently reducing the effective population size.) **However,** over longer time periods, this becomes a significant concern with a small starting population and such a low reproductive rate. At that point you need to consider what would be a minimum viable population over your desired time scale with an appropriate probability of survival, into which a potentially huge number of factors plays, but genetic degeneracy and accident rate (and accident survival rate) would probably be major factors. We already have a number of [questions and answers discussing MVPs](https://worldbuilding.stackexchange.com/search?q=%22minimum+viable+population%22) so I'm not duplicating that here. For some inspiration, while the situation obviously isn't exactly the same, you may also want to look at the [wolf population on Isle Royale](https://en.wikipedia.org/wiki/Wolves_and_moose_on_Isle_Royale) (see also [here](https://www.mtu.edu/news/stories/2017/april/two-pack-no-changes-for-isle-royale-wolves.html), [here](https://www.sciencemag.org/news/2016/04/extreme-inbreeding-likely-spells-doom-isle-royale-wolves) and [here](https://www.sciencemag.org/news/2017/04/two-wolves-survive-world-s-longest-running-predator-prey-study), among many others; use your favorite search engine for more), which is probably one of the more interesting unplanned experiments in the genetics of an isolated population. [Answer] **TL;DR -- Population can be arbitrarily small, but there are risks** Here's the thing... Lack of genetic diversity is a problem, but it's not an automatic death sentence. Low g.d. means two things: * Your population all has the same (or very similar) disease resistance profile. That means they're more at risk of some pandemic wiping them all out. * Your population is similar genetically. That means an increased chance of reinforced negative recessive genes showing up, making for sickly offspring. These can be overcome with proper animal husbandry (or heck, human husbandry!). This is in fact how new breeds are created -- heavy inbreeding, with culling of specimens who are sickly or don't fit in. Note that inbred wild species don't get the advantage of culling; instead you have sick animals running around. The culling happens, but it's a lot slower and hurts the overall population more. And in royal house populations, you can't just go around culling the Crown Prince, right? The popualtion of wisent (European bison) was down below 50 at one point, and has been brought back up to several thousand. See: <https://en.wikipedia.org/wiki/European_bison> . So you can have an almost arbitrarily small number (for sanity, let's say a few hundred), so long as a few rules are followed: * Keep up your medical technology as best you can. You might not get a plague, but if you do, it'll be a doozy. * Be prepared for some real heartbreak. Many children will be stillborn, or have some genetic disease, compared to Earth numbers. But over time, with (shuddersome, but good for fiction) sufficient euthanasia, you will expose recessives, both harmful and good. Interesting discussion here: <https://en.wikipedia.org/wiki/Inbreeding> Money quote: > > Despite all its disadvantages, inbreeding can also have a variety of advantages, such as reducing the recombination load,[16] and allowing the expression of recessive advantageous phenotypes. It has been proposed that under circumstances when the advantages of inbreeding outweigh the disadvantages, preferential breeding within small groups could be promoted, potentially leading to speciation.[17] > > > So, to wrap it up: **Inbreeding is a problem, but a manageable one which does carry risks.** Oh, last word, just for fun. Cheetahs in Africa have such low g.d. that they can almost universally accept skin grafts from one another without problem. So your population of humans will be able to donate organs to one another much more easily... ]
[Question] [ In my story, I plan on having one of my main characters lifted off the ground by a dragon-like creature and carried a couple miles away. Of course the plan involves them surviving the encounter whether or not they leave with a few wounds as well, however there is no modern medicine for them to heal anything remotely fatal. The creature is, again, dragon-like; large, reptilian, curved teeth and talons, and with bat-like wings for flight. Its behavior is predatory with a preference for human flesh, but they have a tendency to take live prey for their young in which case my main character is the victim. For the flight, they would be dangling for quite awhile and again I'm not sure if its realistic that they could last that long being upside down. Would it be realistic if the creature snatched the character without initially harming them, carry them a few miles through the air, and drop them from a decent height without killing them along the way? [Answer] **TL;DR -- You've got to get clever to make it survivable** This is going to be difficult. I'm going to assume dragon talons are similar to scaled-up eagles', because (a) eagles are badass, and (b) I have stats for them. ;D First, eagles grip **hard**: > > A Bald Eagle’s grip is believed to > be about 10 times stronger than the grip of an adult human hand and can exert upwards of 400 psi > or pounds per square inch > > > Second, the pressure **never lets up**: > > The talons are > closed by the muscles, anchored on the leg bones, by contracting the tendons. The tendons are > contained in tendon sheaths. Both the tendons and tendon sheaths have tiny ridges. When the > tendon is contracted the ridges on the tendons and the tendon sheaths interlock, creating a kind of > "ratchet" effect, enabling the eagle to maintain tremendous pressure on the talons without > continuously maintaining the tremendous contraction force on the muscle > > > So at least several minutes, being squeezed by *sharp* talons at 400 PSI ... that is not survivable. Not without geting tricky... Could it be your hero is wearing plate mail? The armor would take the hit, and probably be severely dented, but might allow the guy to survive. Another possibility is that the strike is flawed; instead of getting grabbed, the hero *leaps* at the last instant and grabs the dragon's leg above the talon. Dragon would realize that something is wrong, but figure hey, he's not falling off, and the chicks can get some good rending practice. I'm not too worried about the drop at the end; assume that the dragon doesn't want to risk crushing its chicks, so the drop is pretty low. Also, the nest could have a nice soft lining of sticks, leaves, shed scales, dragon guano, and the remains of previous meals. > > **Update after comments:** The question comes up of whether dragon might consider using a lighter grip to grab the hero. This could be made to work; depends a lot on just how "alive" the dragon wants the prey to be when dropping it off for the chicks, and how well it gauges its strike against the sturdiness of the prey. That is to say, a strike which would cripple a buffalo would obliterate a man. Also, we might have to avoid the whole 200mph power-dive... > > > So ... we can posit that dragon's chicks are getting bigger, they're ready for some "practice" prey. So dragon might have a mode where she *very gingerly* captures the prey with full intent of keeping it alive. This would not be done lightly, as she doesn't want to risk damage to herself, but is a good option for hero survivability. > > > Source of quotes: <https://www.hawkquest.org/TA/XL/Gripping.pdf> [Answer] **The answer to your question is a qualified yes** If you are prepared to hand wave the problems of a flying dragon that can pick up a human then the transportation problem is not too hard. Why not assume that the dragon needs or wants to capture live prey from time to time? Perhaps it wants to train its young or perhaps it wants to keep some meat “on the hoof” in its nest or den if the supply of meat is erratic. If that were the case the dragon should have evolved the capacity to use its talons “gently" and release them “gently". But gently in this context could still amount to broken bones and mild to serious injury - unless you were lucky. [Answer] ## The drop's the only problem with your idea The idea of a person being snatched up and carried by a flying thing is actually quite realistic -- they've both been done IRL, albeit using quite different hardware to what you propose. In the [Fulton surface-to-air recovery system](https://en.wikipedia.org/wiki/Fulton_surface-to-air_recovery_system), a helium-balloon-supported line harnessed to the recoveree was captured using "horns" attached to the nose of the aircraft and special, automatically triggered "sky anchor" hardware. As a result, the airplane would then pull the recoveree up and out of the LZ they had set up in, and then be able to capture the recovery line using a J-hook and winch the recoveree in all the way. Now that we've established that being swooped in on and picked up by a slow-flying thing won't kill you (a Fulton extraction has been described as being gentler than a 'chute opening), the dangling part isn't too big a deal either, although the character probably would want to grab onto the beast's leg to hold their head upright since they won't have the benefit of a harness. Once that's solved, then being flown long distances in open air isn't an issue -- the US military has been doing it since the Vietnam War using harness-and-longline rigs dangling from helicopters (originally the [STABO rig](https://en.wikipedia.org/wiki/STABO) -- the modern [SPIE rig](https://en.wikipedia.org/wiki/Special_Patrol_Insertion/Extraction) is its direct successor). The bad news is that dropping the prey may lead to them going splat if done under unfortunate circumstances. The good news is that if they drop them from a low height, humans have a low terminal velocity (120MPH or perhaps somewhat less depending on how much drag your hero can kick out in a pinch), so it's probably not going to be a fatal or even mortal fall if they land in something soft-ish from 20' or even 50' up (landing in water from 50' up would *suck* though). [Answer] Could you make your dragon-like creature more like a [Wyvern?](http://mythicalrealm.com/creatures/dragon-wyverns.html) It has a sting at the end of its tail, to sting prey with. So just like a [parasitoid wasp](https://en.wikipedia.org/wiki/Parasitoid_wasp) she stings prey to paralyse it and carry it back to her nest. You then have several choices: 1. You hero is paralysed, but it wears off before the young eat him. Perhaps Mother Wyvern wanted him comatose for the trip, but feisty enough to fight back when at the nest, to give her hatchlings some practice at dealing with live prey. 2. As above, but instead of a deliberate short duration, Mother misjudged the amount of venom she injected into him. When I was stung 4 times by a wasp, each successive sting had less venom in it (as indicated by the amount of swelling). Maybe Mother is confused by armour and possessions and her first stings injected the venom into his waterskin, or his rucksac, or really thick winter furs, or something else which does the hero no harm. 3. Perhaps, like the Dread Pirate Roberts and [iocane powder](http://princessbride.wikia.com/wiki/Iocane), your hero has been dosing himself with small amounts of Wyvern venom, to make himself immune! ]
[Question] [ Similar question to [this one](https://worldbuilding.stackexchange.com/questions/57691/how-to-calculate-your-kingdom-s-population-size) except I want to calculate the urban and rural population needed to support an army. I want to create a world for a fantasy wargame campaign using some of the elements from questions I have asked here before. The setting is a desert world where water is relatively scarce, but is otherwise similar to earth. There is a large canal network to move the water where it’s needed across many hundreds of miles and the world is populated by humans. There is a technology level similar to that of ancient Rome 100CE and a civilization based on city states located at the junctions in the canal network. Each city has a fairly large area of influence into surrounding territory. Some are larger some smaller. In order to construct a vaguely realistic campaign in this world I need to consider the population size and spread. Is there a basic rule of thumb that I can use to determine population sizes in rural areas, towns and cities? There needs to be enough people so that each city territory can field an army of between 5000 and 20000 without too much trouble. So in summary what I want to know is for an x thousand man standing army how many people have to live in the city and how many in the rural areas along the canals? Use Roman settlement patterns if I have left anything out. Out of scope: anything to do with how the canals were built or the backstory (and no magic). **Edit** To answer some questions that have been raised: Do they have slavery yes they do as the Romans did. Fighting usually occurs in the spring and summer, although there might be exceptions. Some city states have taken control of others to form small nation states. There is considerable tension along many of the canals in contested areas. I’m not sure how wide the canal irrigation zones are but probably 10-20 miles either side of the canals are agricultural land the rest is desert. There is one harvest per year at a similar time to that which the Romans would have experienced and it is labour intensive. Conscription would not be used except in emergencies. In such cases any males from the population who might be reasonably fit and capable in a fight (say 15-55 year olds) might be called up for the duration of the emergency. **Edit2** Map added of the top half of this fictional world in case anyoen is interested ![Map sample]](https://i.stack.imgur.com/3PVmJ.jpg) [Answer] **Copy something real.** * Pick a city of the ancient world of roughly the time period you want. There are many which could be candidates. Cairo. Alexandria. Samarkand. * Duplicate that city in your fiction. Most readers will not be familiar enough with the ancient world to identify what you have lifted. If you are an excellent writer an occasional one might (especially if you decide to include the Hagia Sofia in your city); that is fine and part of the fun. [Kandahar](https://en.wikipedia.org/wiki/Kandahar) would be a fine choice. [![Kandahar](https://i.stack.imgur.com/RhNVR.jpg)](https://i.stack.imgur.com/RhNVR.jpg) Kandahar was founded by Alexander the Great and by the time period you state was a regional capitol. It is hard for me to find population estimates for the ancient city, but comparable cities had populations in the low hundreds of thousands and certainly the surrounding countryside would have many more. As regards how to estimate populations I found this. [![estimating populations for ancient egypt](https://i.stack.imgur.com/ip5tL.jpg)](https://i.stack.imgur.com/ip5tL.jpg) from [The Complete Cities of Ancient Egypt, Stephen Snape.](https://books.google.com/books?id=6wg7CwAAQBAJ&pg=PT28&lpg=PT28&dq=carrying+capacity+countryside+egypt&source=bl&ots=NUJq5FcfOj&sig=_j8ovHHnQ36q5T5KmVd0pSPf3KY&hl=en&sa=X&ved=0ahUKEwiIivmz8bbXAhUo_IMKHWv_AwcQ6AEIOjAH#v=onepage&q=population&f=false) They discuss various ways to estimate population for ancient periods, either based on likely productivity of the land or extrapolating from urban populations to what would be needed to support them with food. You are probably not going to find a place with better archaeological / historical records than Egypt. Maybe Greece or Italy. Note that urban population is not one city but all urban centers of the time. I cannot recall reading a work of fiction that got so far into the weeds as to discuss population density and irrigation practices. I suspect people who are thrilled by such are not reading fiction. --- I figured Alexandria and Cairo must have had canals. In fact all of these ancient drylands cities had canals. You can see one in the above photo of Kandahar. It turns out that the ancient underground canals of Alexandria were once a tourist attraction, and might be again. <http://www.touregypt.net/featurestories/alexandriacisterns.htm> > > This is fortunate because these subterranean canals were frequently > described as underground cathedrals. Sometime between 1710 and 1712, > Francois Paumier, a member of the third order of St. Francis, > exclaimed with admiration, "there is nothing more beautiful and > complete than the vaults; nothing better constructed than their > apertures; nothing more superb than the pieces of marble with which > they are surrounded". Seventeenth and eighteenth century artists, > including the scholars of Napoleon, though enough of these monuments > to make numerous engravings, which give us an idea of their imposing > proportions. > > > [![roman cisterns of alexandria](https://i.stack.imgur.com/IA71u.jpg)](https://i.stack.imgur.com/IA71u.jpg) [Answer] There is a **very rough** rule of thumb that ancient farming methods could support one non-agricultural worker for every ten agricultural workers. Families are included in these numbers, because they will do useful stuff -- watching the herds, spinning wool, cooking for the peasants, watching the manor, spinning wool, teaching the children for the upper classes. * That means one farm worker produces food for 1.1 people. If agriculture is a few percent more or less efficient, the ratio of non-farmers to farmers will change by a *much* greater percentage! * Except for very short campaigns, there is a limit on the number of soldiers who can be mobilized. If more than 9% of the men are called up, there are not enough left to work the land and feed everybody. * More likely, perhaps one in ten non-farmworkers can become a soldier. That would give a ratio of 100 agricultural workers to one soldier. Of course a society could compensate by mobilizing women, children, and elders even more than the 10-1 ratio assumes, but I'm already assuming that they contribute anyway. So 10,000 soldiers might be part of 100,000 non-agricultural workers. Say half of them live in cities, half in smaller towns and manors or villages (assume an even split). They are fed by 1,000,000 farmers in manors and villages. Since that is just counting the able-bodied men, triple or quadruple the numbers to get the total populations. * 4,000,000 farmers and their families in villages * 90,000 non-farmers and their families in villages * 90,000 non-farmers and their families in towns * 180,000 non-farmers and their families in cities * 30,000 military dependents *(Decide where they live. Manors? Cities?)* * 10,000 military 4,400,000 people total --- *Follow-Up:* I assumed that one quarter of the population would be men of somewhat military age. The assumption is that half of the population will be women and that half of the men will be too young or too old to fight. And "one in ten" or "ten percent" are very rough guesstimates. Make it "one in eight" or "one in twelve" and the army size changes accordingly. Just like the division of populations between cities, towns, and villages/manors, this would be one area where some of those **fictional** countries get their distinct look-and-feel. * One country might have laws and economic patters which favor manors with absentee landlords, operated by slaves and overseers. Few little towns, and most freemen are in the cities where skilled craftsmen compete with factory slaves. * Another country might have laws and traditions that keep craftsmen at the village and town level, serving the needs of yeomen farmers. The cities are little more than rural towns with an attached palace and a few bureaucrats, plus the service sector to keep them fed in style. * One country might be oppressing the peasants, so they **don't** draft them as a militia, and they **don't** dare to call up too many of the combat-trained gentry away from their manors, either. * Another country has the tradition to train **all** young men to fight, and they call them up by age group -- first the current draft, if they need more then last year's reserve, and so on. On paper they can field enormous armies, but if they do that they cripple the ability to arm and feed them. * Another country uses their standing army as a **labor pool** for civil engineering projects in between battles. (Or has them grow food to feed themselves, for that matter.) That allows them to increase the size of the army relative to other sectors of the workforce. * Yet another country trains both men and women of their "fighting classes" to fight (whatever those "fighting classes" are, see above). They deploy all the men to fight in their expeditionary forces, and still have a substantial garrison at home. [Answer] Ballpark numbers: * Grain farming takes about 1 acre per person, more in drier climates. You also need land for other uses for the peasants -- wood for heating, pasture for livestock. You would be reasonable to use 200 people per square mile. Rice permits somewhat lower land requirements. Irrigated land can double the productivity, as can the right climate. Drought can reduce the crops to 1/5 of normal. * Stirling in his Emberverse books cites 3% It takes around 30 peasants to provide the resources for a man at arms. This fits with other numbers I've seen. Another answer here cites 10 peasants per non-peasant. Given that any culture that creates more than mobs armed with clubs requires other non-peasant/non warrior personnel,(E.g. the local village has a miller, a black smith, an inn keeper, all with their assorted minions, the manor house with servants...) I'm inclined to go with 3%. * The working class as fighters didn't happen much until firearms. It takes a long time to become competent with sword, pike, sling or bow. (I'm sure someone will find exceptions to this... Warrior cultures such as the Mongols and the Spartans) Professional soldiers coming up against peasantry does not end well for the peasants unless present in overwhelming numbers. Mind you, the Romans ran into some nasty surprises in what is now Germany -- special circumstances. These exceptions make for interesting sub-scenarios in a military game. That said: A pruning hook isn't much different from a halberd. A scythe blade can be remounted as a pike blade. * If you get the peasants involved, you need to do this after planting and before harvest. One the reasons the Irish have a rep for fighting: Potatoes are an easy crop that takes little care. * If you look at the French Indian wars in North America (7 years war in Europe) you find long marches by absurdly small forces making significant changes in the strategic situation. Francis Parkman has a series of books on these wars. They have to be read with consideration of his British/settler vs French/Indian savage bias, but for some idea of the personalities and logistics they have much merit. ]
[Question] [ Most communications systems are intensely dependent upon the order in which you transmit information. For example, a binary code, like Morse Code, cannot convey information unless the order of the dots and dashes is strictly controlled and can be reliably transmitted. But, what about the opposite situation? Imagine a language that evolve in, or was designed for, a context where you could not be assured of the order in which your words were transmitted. Maybe it was usually transmitted one word at a time carrier pigeon-style by insects that could only carry one word each and traveled in swarms, or by groups of balloons carrying one word each whose order could be jumbled by air currents, or by sounds contained in bubbles whose flow through water could be jumbled by water currents, or by sound in caves with such intense echoes that the order of the words would be heard could not be reliably predicted, or by spies none of whom could be trusted with the entire message whose duration of travel could not be easily predicted relative to each other. Suppose also that any of these potential methods of communication has a fairly high rate of losing words in transmission, maybe 2%-5% of the words transmitted would be lost in a typical communication (something that would seem likely to be the case in any of the examples of a means of communication where word order would be routinely compromised). **What features would a language that works well in these conditions have to have to function?** Real world examples of languages developed for use in these conditions, if any, would obviously be one way to provide a convincing an answer, although not necessarily the only one. [Answer] **Language is not just words** Firstly, there seems to be an odd assumption that words are the be all and end all of language. Tone, punctuation and grammar and physical gestures are all part of language too. I can't remember the specifics but a high percentage of communication is non-verbal. Just because your words don't all come out, or come out in an odd order, doesn't mean you're not going to be understood. After all, if we are unable to speak clearly ourselves we often use gestures and exaggerated tone to be understood. Therefore, a language that could not rely on word order or transmission would become heavily reliant on these things. The world of The Expanse has a conlang (Belta) that is designed to be clear even through spacesuits and as such uses lots of gesture to back up the words being spoken - presumably in case of poor transmission. [Answer] This is not as hard as it may seem. There are plenty of natural languages that do not have a regular word order and allow a great deal of word omission. Russian and Japanese are good examples of such languages. Although, they use slightly different approaches to solving the same problem. ## 1. [Inflections](https://www.wikiwand.com/en/Inflection) Inflections are modifications of a word that express different types of grammatical relationships with other words. English does not use inflections that much, they are mostly limited to verb conjugation. Therefore, the word order becomes important to signal a grammatical role of a word. (*Bob eats fish* has an opposite meaning from *Fish eats Bob*) Other languages use inflections extensively and do not need a regular word order to indicate grammatical relationships between words. For example, [Russian](https://www.wikiwand.com/en/Russian_grammar) uses endings to signal whether a noun is a subject or an object and if it is the object its ending communicates a specific relationship with a verb. No native speaker will confuse *Боб ест рыбу* [Bob yest ribu] with *Боба ест рыба* (Boba yest riba) [the same meaning as in English examples]. In languages like this, word order is frequently used for emphasis and expression of nuances. ## 2. [Particles](https://www.wikiwand.com/en/Grammatical_particle) Another approach is the usage of grammatical particles. They play the same role as inflections but in a way are closer to prepositions. [Japanese](https://www.wikiwand.com/en/Japanese_grammar) is an example of this type of languages. Particles indicate relationships between the words: * ボブが魚を食べる (bobu ga sakana wo taberu) -- Bob eats fish * 魚がボブを食べる　(sakana ga bobu wo taberu) — fish eats Bob, where *ga* marks a subject, while *wo* marks an object. Particles must be attached to words, but 'word+particle' construction can be moved around without much change in the meaning. It is important to note that while Japanese has a much freer word order than English it is still not as flexible as Russian. In Japanese, a phrase must end with a verb or a verb-like word. Modifiers must always precede what they modify. Russian does not have these limitations. ## 3. [High-context culture](https://www.wikiwand.com/en/High-context_and_low-context_cultures) High-context cultures heavily rely on background knowledge and context. Messages tend to have additional implied meanings not openly stated in words. Communicators in such cultures frequently omit words or even phrases if they can be easily derived from context. For example, Japanese rarely use 'I'. It is also not uncommon for Russian speakers to omit a subject (including I) if it is clear who they are talking about. --- Your language could rely on a mix of inflections with particles. Combined with a high-context culture, it would have both requested features: flexible word order and resistance to omittances. The bonus feature is that people from high-context cultures are usually very observant since they literally need to read between the lines. [Answer] You could have each word take the last half of the previous word and the first half of the next word as prefix/suffix. As an example: Hello World! -> .HelloWor lloWorld! Note the . At the beginning of the message to indicate message start (essentially saying ‘the word before this one is an empty sentence’) This allows you to take a pretty decent crack at word ordering and also can be used to reconstruct or guess at missing words.you may, however, want to define one character to be ‘word start’ and one to be ‘word end’, so if start is X and end is Y then: XYayY XLinguisticsY! -> .XYayYXLingui ayYXLinguisticsY! Of course, you can replace X and Y with more pronounceable character sets. Some issues: It’s still possible to lose words if multiple adjacent words are lost. ‘Decoding’ the message could take quite a lot of effort Individual words might start exceeding your total word length if you have three long words one after another. [Answer] One way to do this would be to use words which symbolize entire sentences. Of course that would mean there would be a lot of words in this language, but if both sides had a dictionary which was regularly updated then it would work. [Answer] # Add words that replace the function of the word order First, many already existing languages have quite loose word order rules, and you can still understand a sentence even if you put the words in a non-standard order. For example... English: 1. Where did Alice go? 2. Alice did go where? 3. Go where did Alice? 4. Did Alice go where? For the sake of an argument, let us make this a bit trickier and make the word order matter. Compare: * Did Bob go there * Bob did go there Now we have changed meaning of the sentence by changing the word order. The first sentence is a question. The second is a statement of fact. How can we resolve this? **We add a keywords that take the function of the word order** * Bob question go there * Go Bob there fact Now granted this cannot replace **all** the functions that word order affect. A sentence with enumerations and particularly multiple enumerations become next to impossible to do without word order — or at least word **pairing** — being relevant, such as: * Alice and Bob did go there but Carol and Dave did not ...but that can be solved in other ways. ## Summary A language without word order is quite feasible. The main features of it would be: * Words are added to indicate things that word order otherwise does, such as whether the sentence is a question or a statement. * You can expect the language to feature shorter sentences since long sentences in the language(s) that you are accustomed to depend heavily on word order to make sense. [Answer] You're effectively describing a communication protocol that matches the [UDP](https://en.m.wikipedia.org/wiki/User_Datagram_Protocol) network communication protocol. In simple terms: the message is split into packets, and those packets are shoved towards the recipient. The protocol does not guarantee packet order, nor that no packets are lost in transit. You can't directly copy the various solutions that sprung up around it, but you can certainly take inspiration from them. There are three main issues when dealing with this kind of unreliable data input: * ordering: how should you sort all the bits you received? * verification: is anything missing from the received message? * error correction: bits and pieces are missing, can we still understand the message? Ordering is relatively simple: you attach an index number to each "word". UDP generally uses [checksums](https://en.m.wikipedia.org/wiki/Checksum) for validating data integrity. Your language could incorporate these at a basic level (words in sentence describing word count and properties of sentence). There are [algorithms](https://en.m.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_correction) for effectively using redundant data (QR codes use this to be readable even after somebody drew on them with a sharpie). Using these ideas in natural language would take significant adjustments though. ]
[Question] [ Ever since reading through the creative answers in this question ([How can I explain alien skin being different colors?](https://worldbuilding.stackexchange.com/questions/52595/how-can-i-explain-alien-skin-being-different-colors)) I've been thinking about the logistics behind fantastical skin colors. However, one part that stuck out to me was the idea that pH levels could influence a creatures outward appearance. One of the more promising things I found relating to that was bromothymol blue. Bromothymol blue is a pH indicator that has a range of colorless to bright blue, but with human blood levels would likely appear between tealy-green to muted turquoise. It is usually used to test amounts of carbonic acid, an element that already exists to some extent in human blood. This leads me to main questions: * How can a humanoid creature maintain this pH indicator in its physiology (as in, not immediately flushing it out of the system or dying of exposure)? * How can I make the effects of the bromothymol blue manifest on the skin? * As a bonus, are there any other chemicals that could work in a similar way and not require too many changes to human biology? [Answer] What worries me about the bromothymol blue proposal is that it doesn't appear to be an organic chemical, i.e. no living organism produces it. This means that it's not possible (or at least unlikely) to be created in nature, and it would have to be artificially replenished. Those are obviously some big hurdles to overcome. There are [naturally-occurring pH indicators](https://en.wikipedia.org/wiki/PH_indicator#Naturally_occurring_pH_indicators) that serve just the way bromomythol blue does, for your purposes. * [**Anthocyanins**](https://en.wikipedia.org/wiki/Anthocyanin) are synthesized in plants through the [phenylpropanoid metabolic pathway](https://en.wikipedia.org/wiki/Phenylpropanoids_metabolism) in certain plants, using a number of enzymes. For this synthesis to work, an organism would in turn need to synthesize the enzymes used in this pathway. This is often a bit of a problem when it comes to introducing new chemicals into an organism: There are way more intermediate enzymes and proteins that are needed, and a delicate balance must be maintained. Still, it's not an impossible task - just a very difficult one. Anthocyanins are non-toxic to humans, so it shouldn't be a danger to your organisms. * In [**Hydrangea macrophylla**](https://en.wikipedia.org/wiki/Hydrangea_macrophylla), the color of the flower [is determined by levels of aluminum in the soil](http://www.usna.usda.gov/Gardens/faqs/hydrangeafaq2.html). Without aluminum, [red anthocyanin dominates](http://www.somethingaboutscience.com/?p=1683); when some sort of water-soluble aluminum compound is added, it can bind with the anthocyanin and turn the flower blue. To harness this, you'd want to look and anthocyanin production again, and determine how aluminum could get to the organism's cells (I'm assuming it would come through diet). Once again, you *probably* won't have toxicity issues. * [**Litmus**](https://en.wikipedia.org/wiki/Litmus) is the result of naturally-occurring compounds found in lichens. Unfortunately, it's a complex mixture when it works the best, but its properties are mainly [due to a chemical called 7-hydroxphenoxazone](https://chemistry.stackexchange.com/a/2841/13294), based in part on [phenoxazine](https://en.wikipedia.org/wiki/Phenoxazine). I don't know whether a single organism could produce all of the constituent compounds. I imagine that the main production centers of whichever indicator you choose would be near the top layers of the skin. Currently, [special cells called melanocytes](https://en.wikipedia.org/wiki/Melanocyte) create [melanin](https://en.wikipedia.org/wiki/Melanin), which determines skin color. All you have to do is swap out melanocytes for whatever modified cells you design to create the pigments of your choice. They'll reproduce the pathways found in plant cells to produce the indicators, but that doesn't mean that they'll have all of the same features (e.g. cell walls) of plant cells. They'll be hybrids, really. [Answer] There are [people with blue skin](http://abcnews.go.com/Health/blue-skinned-people-kentucky-reveal-todays-genetic-lesson/story?id=15759819) in real-life. This has something to do with hemoglobin. > > A blue skin tone can be caused by [methemoglobinemia](http://emedicine.medscape.com/article/204178-overview) where an excess of methemoglobin (a form of haemoglobin that contains ferric iron rather and ferrous iron and is useless or very poor at carrying oxygen in the blood) builds up. This can occur if there is a deficiency in the enzyme called cytochrome-b5 methemoglobin reductase which converts methemoglobin into haemoglobin. > > > Normally, people have less than 1 percent of methemoglobin. Between 1 and 10 percent does not have much effect and levels greater than 20 percent tends to cause heart abnormalities, seizures and even death. But at levels of between 10 and 20 percent a person can develop blue skin without any other symptoms. > > > Incidences of methemoglobinemia are extremely rare, but do occur and one family in particular is on record as having been seriously affected. > > > [Martin Fugate](https://en.wikipedia.org/wiki/Blue_Fugates) came to Troublesome Creek in eastern Kentucky from France in 1820 and family folklore says he was blue. He married Elizabeth Smith, who also carried the recessive gene. Of their seven children, four were reported to be blue. > > > There were no railroads and few roads outside the region, so the community remained small and isolated. The Fugates married other Fugate cousins and families who lived nearby, with names like Combs, Smith, Ritchie and Stacy. > > > Benjamin Stacy, born in 1975, is the last known descendent of the Fugates to have been born exhibiting the characteristic blue color of the disease, but lost his blue skin tone as he grew older. Benjamin "Benjy" Stacy so frightened maternity doctors with the color of his skin "as Blue as Lake Louise" that he was rushed just hours after his birth in 1975 to University of Kentucky Medical Center. > > > As a transfusion was being readied, the baby's grandmother suggested to doctors that he looked like the "blue Fugates of Troublesome Creek." Relatives described the boy's great-grandmother Luna Fugate as "blue all over," and "the bluest woman I ever saw." > > > The most detailed account, "Blue People of Troublesome Creek," was published in 1982 by the University of Indiana's Cathy Trost, who described Benjy's skin as "almost purple." > > > The disorder can be inherited, as was the case with the Fugate family, or caused by exposure to certain drugs and chemicals such as anesthetic drugs like benzocaine and xylocaine. The carcinogen benzene and nitrites used as meat additives can also be culprits, as well as certain antibiotics, including dapsone and chloroquine. > > > Dr. Ayalew Tefferi, a haematologist from Minnesota's Mayo Clinic. Is reported to have described methemoglobinemia patients' lips as being purple, their skin as being blue and their blood as "chocolate colored" because it is not oxygenated. > > > See also <https://www.livescience.com/34410-blue-skin-argyria-methemoglobinemia.html> [Answer] It depends on what level of change you are willing to accept to the humanoids biochemistry skin colour changes are “easy” to achieve in nature. By easy I don’t mean simple I mean that there is sufficient biochemical variety available in nature to produce almost any coloured effect you want given sufficient evolutionary pressure and time. The Octopus is one case in point as can be seen in the videos here: [video1](https://www.youtube.com/watch?v=3Bt1LvpZ1Oo) [video2](https://youtu.be/aoCzZHcwKxI) If you specifically want to use bromothymol blue then I doubt this could be achieved without very extensive reworking of human biochemistry, although I suspect it would be possible. One good human friendly option might be to take something that works in a vaguely similar way to haemoglobin which has a red – blue colour change based on oxygen and carbon dioxide balance. If the venous blood and arterial blood were both carried close to the surface the body could more easily switch between the two in a process similar to blushing. Another option would be to include hemocyanin in the blood as used by the octopus but this would involve considerable metabolic rearrangement. ]
[Question] [ This is one of a series of questions dealing with the magic explained below: > > In my fantasy world, magic is an energy similar to radiation. It alters the DNA of living cells, causing them to mutate or die. There are people in this world capable of controlling the magic. They can control the change, using magic either to kill cells, or change them in a host of beneficial ways. For example, they might give themselves night vision by altering their own eye cells. > > > This particular question deals with the speed of the magic. How fast could a magic-wielder work change in his victim? Is it instant, a long, slow process, or somewhere in between? Remember that magic is for all purposes controllable radiation. It works on a cellular basis and can only affect a cell's DNA. Magic should affect DNA at the same speed radiation does. Disregard for the moment any time required for the magic-user to control the magic. Please let me know if additional details are required. [Answer] Radiation changes DNA instantly; for all practical purposes. The ***killing*** of cells takes minutes or hours, when they can no longer produce energy and waste builds up and smothers their ability to work. That said, even if a ***change*** to DNA can give you night vision, there is going to be a growth process for those cells to reproduce and replace other cells in the eyes. Or anything similar, if the user wishes to change their appearance, or grow taller, or change gender or natural hair color. For such growth processes, you should expect them to work no faster than any other biological growth, radiation will not speed that up in the slightest. So on some simple changes (night vision, skin color) consider it like the time from cut to fully healed scar; which is generating new cells and clearing away dead cells. Bigger changes (growing taller by two inches) would take months to year. Changing gender could take several years (based on an approximately six year biological process for a pre-pubescent human female to change into a fully adult woman that is no longer changing due to puberty; I presume reversing that process (woman->man) would take at least as long). [Answer] If all you want magic to do is kill cells, it should work as fast (and in the same way) as radiation therapy. On a scale of hours. But if you want to cause an effect by changing the DNA of a cell, the time scale will be much longer -- months or years or generations. Here are some examples in order of time scale: 1) Make the subject high. Up-regulate production of dopamine in neurons in the medulla and the adrenal glands. If your magic can affect all of them at once, then the subject should start feeling giddy within hours. If you can only change one gene in one cell at a time, then this spell is useless to you. 2) Make the subject able to digest wood. Splice genes for lignin-modifying enzymes into some of subject's gut bacteria. Feed them sawdust. It might take a week or two for the wood-eating bacteria to out-compete unmodified bacteria. 3) Make the subject glow. Splice luciferin genes into some of the subject's skin cells. Wait for those cells to multiply and somehow make sure the glowing cells have an advantage over unmodified cells. Over the course of the next month or two, glowing patches on the subject's skin will grow together until the whole epidermis glows. 4) Horns. You'd have to do the same sort of thing as in (3) but with the subject's ostoblasts. Their turnover time is high ([here's a nice list](http://book.bionumbers.org/how-quickly-do-different-cells-in-the-body-replace-themselves/) of the turnover rates of different types of cells) but they still have to grow the bone. It'll probably take six months to a year to get decent horns. Other growth modifications like bony armor or changes to general body shape will take longer. Some will be impossible to work on adults, but will work on pre-puescent children or infants. 5) Wings. You'd probably need to modify an egg or sperm cell or a blastocyst and wait for the baby to grow. [Answer] Since the magic is intended to work like radiation, it would be logical for speed to work like irradiation: depending on the dose received and the exposure duration. For example, a high dose of magic can make an important change quickly, while a small exposure deals little change and is more of a long and slow process. Moreover, speed varies depending on the organ exposed - an internal organ needs more exposure. [Answer] ### Radiations: Radiations are the most flexible part of your magic. You can tune their intensity, wavelength according to the proficiency of the mage. From weak radio waves to a powerfull laser. Therefore, when it comes to destroying cells or altering DNA, it all depends on how you manage magical energy. There could be some property changes depending on wavelength, like color change for standard radiations... As for travel time - it's lightspeed. ### Mutations: DNA is only used during the formation of the cell, during/after duplication. Therefore, for your magic's effect to start producing mutated cells you'd have to wait for at least one duplication. But duplication rate varies a lot depending on what kind of of cell it is. The body can produce about 2 millions blood cells per second while some cells of the eye won't duplicate even once in a lifetime. That means that it would be faster to grow new eyes, or replace the existing ones than waiting for the originals to mutate. Those limitations can bring interesting elements, like blood magic used to kickstart a mutation on another body part (actually, blood cells are produced by other organs, bone marrow and potentially liver, so technically this example wouldn't work) or accelerating duplication which would be consuming more of the user's energy and increasing the chance of random, dangerous mutation (some kind of magic instability)... [Answer] Given that your magic is essentially radiation, the effects take place on two time scales: Individual magical interactions would take place **at the speed of light.** Individually these won't have a noticeable effect, which is why *the speed of change will depend almost entirely on the magic output of the wielder* and the number of interactions necessary to effect the change.\* The faster the magical radiation is delivered, the more interactions will take place and so the faster the change. Likewise the more interactions required, the slower the change. We can express this relationship via the formula: **Time = Output / Interactions** \*Plus the time required to control the magic, which (as per the question), we're ignoring. [Answer] The energy transferred to a substance through electromagnetic radiation depends on two factors: **1. The energy of the individual photons** Energy is directly linked to wavelength (the "colour" of the light). Microwaves will transfer more energy at the same intensity than radio waves. Visible light will be higher than both, and getting up to X rays or gamma rays will allow to magic to impart energy at a higher rate. **2. The intensity of the radiation** This is the number of photons emitted per second (the "brightness" of the light). Higher intensity means a higher energy transfer rate. **Balancing these two** An object has a colour because it absorbs some wavelengths of light, and reflects the other wavelengths that result in its colour. This means that magic users may have to use the correct wavelength to be absorbed by their target. As a general rule, the shorter the wavelength the more likely it is to be absorbed. (Most things reflect radio waves, but gamma waves are pretty much lethal to everything.) This means that a higher level magic user may be able to use higher frequency radiation, which lets them use magic on more difficult targets. Some frequencies can pass through certain objects, such as a window which is transparent, but reflects a small proportion of the light that hits it. This could be taken into account by your magic users. The intensity of light will change the rate of energy transfer (and the speed of spells). Perhaps higher level magic users can use higher intensities? ]
[Question] [ Long story short, this civilization found very little oil and natural gas in their world (or maybe they ran out of both), but there are huge deposits of amber and special pine trees which produce rather energetic resin (source of that amber). Let's assume that both amber and resin are not unlike the ones we have on Earth. Can they be used as viable fuel sources for a steam engine? **update**: Ok, let me ask a little more specific. I have a world with little to no oil and natural gas, but with big reserves of amber, some coal (there is a lot of amber => there were a lot of pines at some point in a distant past => they left coal) and pine trees that produce resin. What would serve as a better fuel source for a steampunk civilization (late XIX century, if compared with our history): * coal (won't last more than a century or two) * amber (way more than coal, but is it as good as coal?) * wood (slowly renewable) * or pine resin (renewable)? [Answer] ## Amber and pine resin will burn Since [amber](https://en.m.wikipedia.org/wiki/Amber) and pine resin are both hydrocarbon molecules, they will [burn](https://amberregina.com/test-amber) in the presence of oxygen. However, actually burning amber requires much higher ignition temperatures. On the way to ignition, the amber melts into an asphalt/tar-like mixture which eventually ignites. This [forum thread](https://maestronet.com/forum/index.php?/topic/331768-melting-amber/) talks about turning amber into varnish but discusses a lot about the behavior of amber at elevated temps (>400°F). It's messy. Some refinement process may be required to get unprocessed amber to the lighter grades of petroleum that we see in modern gasoline or diesel. I'm not enough of a chemist to say what would be required in that process. ## Preferred Fuel Source Since steampunk usually runs on solid fuel such as coal, a furnace that burns amber would probably be the most economical. Amber is the more abundant fuel source and I trust that inventors will figure out ways to deal with the whatever ash is left behind. There may be energy density differences between coal and amber, in which case the higher cost of coal may be more cost effective in some situations. Since amber isn't commonly used as a fuel, someone with more chemistry than I will need to calculate how much energy is locked up in the hydrocarbon bonds in the amber. [Answer] A quick Google gave me this link: <http://onlinelibrary.wiley.com/doi/10.1002/fes3.13/full> It mentions using turpentine extracted from pine resin as a diesel additive (improving emissions and engine performance) and as an alternative fuel for jet engines. I think turpentine on its own may be too volatile to be an effective fuel for heating water, but perhaps there are refinery processes that would make it more suitable. I'm not enough of a chemist to know. [Answer] **From an energy content perspective, amber would be roughly equivalent to soft (high non-carbon content) coal.** Fossilization doesn't add any energy (absent some really strange corner cases), so I don't see it being much better than the same mass of dried wood. Quantities of amber large enough to burn strikes me as stretching it, for story plausibility. **What the resins give you is the possibility of extracting/distilling into a liquid fuel** (turpentine or similar.) Liquid fuels are *much, much* easier to work with in many ways. **And liquid fuels that don't produce significant solid ash can be used in *internal combustion* engines.** That's something that could change how a world works. [Answer] ## Fossil Fuels You say you don't have a lot of oil or natural gas, but you're limiting your fuel sources. You can get natural gas from coal via the [coal gas reaction](https://en.wikipedia.org/wiki/Coal_gas). That's the source of the gas used for gaslight in Victorian times. ## Other sources of energy **Pine Trees** Pine resin can be refined into [turpentine](https://en.wikipedia.org/wiki/Turpentine), which—as @egor045 mentioned—[can be used for fuel](https://en.wikipedia.org/wiki/Turpentine#Niche_uses). With all those trees, you've got yourself a massive potential source of wood alcohol (methanol), another potential fuel. Lots of pines means lots of pine nuts, which can be used to produce [pine nut oil](https://en.wikipedia.org/wiki/Pine_nut_oil), as well as delicious, delicious, pesto. That's another source of fuel (the oil, not the pesto). **Other plants** Diesel's first engines were designed to run on peanut oil. The Model T's engine can run on ethanol. Distillation of alcohol could be done using pines as a fuel, or, if the climate gets cold enough, by [freeze distillation](https://en.wikipedia.org/wiki/Fractional_freezing). Get yourself some high-proof hooch, spike it with methanol to keep people from drinking it (drunk driving is bad) and you've got yourself a great power source for an internal combustion engine. As for oil for diesel-style engines, why not use an existing plant that is high in oil like [sunflowers](https://en.wikipedia.org/wiki/Sunflower_oil), [rapeseed](https://en.wikipedia.org/wiki/Rapeseed), or [peanuts](https://en.wikipedia.org/wiki/Peanut_oil). You could invent your own plant, too. Make it high in usable oil, but have that oil be difficult to extract or useless without some piece of technology or recent discovery and you'll have yourself the foundation of an oil economy. **Hydropower and wind power** The Industrial revolution didn't start with steam power. It started with water and wind power. Mills and factories ran on waterwheels long before people discovered that lightning wasn't Zeus throwing another temper tantrum. It was windmills that pumped out the [Zuiderzee](https://en.wikipedia.org/wiki/Zuiderzee). Electricity generated from these methods could be used to power things directly, or in the manufacture of something (e.g. methane) that will work as a fuel. **Hydrogen** With 19th century technology, you've got the ability to use the electricity generated in some other way (whether or not that way is detailed here) to [electrolyze water](https://en.wikipedia.org/wiki/Electrolysis_of_water). That gets you hydrogen and oxygen. The oxygen can be sold off to people exploring the ocean or really tall mountains. The hydrogen burns, and will do so quite energetically, but might be better used in the [Sabatier reaction](https://en.wikipedia.org/wiki/Sabatier_reaction) to produce methane (i.e. natural gas). [Answer] There is already a tree that produces resin that can be directly used as a fuel source, the copaiba "diesel tree" of the Amazon ([Copaiba tree info](https://hort.purdue.edu/newcrop/duke_energy/Copaifera_langsdorfii.html).) Reportedly this tree can be tapped for the sap which can then be used directly by a diesel engine, or converted into bio-fuel. Not hard to imagine a process that converts the sap into a hard amber resin that could be stored and used like coal (though if you have liquid biodiesel I'm not sure a coal form would be necessary). So you could replicate a lot of the industrial era energy conflicts with this model. Standing copaiba tree groves would have to be protected and harvested (probably requiring slave labor) while there could be mines for the amber. Of course in a pre-petroleum world there were also animal fuel sources, such as sperm whales, so your world may have a similar creature as well. Of course if they have biodiesel why would they bother with steam engines instead of far superior diesel engines? Well, running pure biodiesel (B100) is really hard on internal combustion engine valves and such. So without petroleum to cut it with, it is quite possible that the ICE wouldn't take off as maintenance was a nightmare, so using bio-diesel just as a heating source for a steam engine may end up being more efficient and sustainable. ]
[Question] [ Imagine that you want to colonize Venus. But a day on Venus lasts 4 months, and that's terrible. The big brains at the Science Palace have decided to make Venus spin faster, so that the length of day would be correct (one of the big brains suggested putting opaque shields into orbit that would artificially create night-time, but he got demoted). What is the lowest tech level at which this idea is plausible, and what would it look like? Would there be any fun side effects of the method/its results? [Answer] The amount of angular momentum in a planet is incredible; planets are like giant gyroscopes. The lowest tech level required would be "Dyson Sphere," because you'd need MASSIVE amounts of energy to attempt to add angular momentum to the planet. Also note, due to conservation of angular momentum, you're going to need to "steal" momentum from an absolutely massive ... mass. We're talking, somehow transferring the angular momentum from Mars. As for "fun side effects," let's say you have a Dyson Sphere, or a Dyson Ring to collect power. You use this to build an absolutely massive space ship; basically, it's engines surrounding a huge conglomeration of asteroids. Maybe you even turn Ceres into your vehicle. You fly Ceres to Mars, and use tractor beams on the north pole. This causes angular momentum to transfer to the ship, which you then whirl on to Venus, and use tractor beams on the south pole to re-transfer the momentum from the ship to Venus. Do this a couple trillion times and Mars will be tidally locked to the Sun, while Venus is spinning a bit faster. Of course, once you've spent that much fuel, you might just put ion thrusters on ships, tractor beam them to the poles, and then fire rockets to rotate the ships (the angular momentum comes from the particles ejected into space). This is a MASSIVE undertaking; we're talking about fantastic amounts of energy required. Equal, perhaps, to the energy required to initiate warp drive on a ship, to boldly go somewhere with habitable planets. Or, eat a bit of crow and rehire the guy with the sunshield idea; it'll be way cheaper than a Dyson Ring, and makes a great place to put orbital solar power stations. [Answer] The [rotational energy](https://en.wikipedia.org/wiki/Rotational_energy) of an object is $$ E\_{\mathrm{rot}} = \frac12 I \omega^2 $$ where *I* is the [moment of inertia](https://en.wikipedia.org/wiki/Moment_of_inertia) and *ω* is the [angular velocity](https://en.wikipedia.org/wiki/Angular_velocity). The [moment of inertia of Venus](http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html) is about 5.88×1037 kg·m², and its angular velocity is about 3×10−7 rad/s (sidereal rotation period of 5832.6 hours); this results in a rotational energy of 2.63×1024 J. If the rotation of Venus were to be accelerated so that it had the same sidereal rotation period as Earth, that is, 23.9345 hours, its rotational energy would increase to 1.56×1029 J. The [total amount of energy produced](https://en.wikipedia.org/wiki/World_energy_consumption) by the human civilization in one year is about 14000 Mtoe (millions of tons of oil equivalent), or 5.86×1020 J. Accelerating the rotation of Venus so that it would have the same sidereal rotation period as Earth would require 267 million times more energy than what the entire human civilization produces in a year. I think that it is safe to say that a project which requires 300 million times more energy than what the entire world produces in one year won't be undertaken any time soon. [Answer] Human civilization already has a technology to do this (with a few caveats). The idea is to direct a large enough planetoid to collide with the planet to give it much needed angular momentum. This is probably how Earth acquired its faster spin in the past. The caveats are: 1) there should be a suitable planetoid in the system 2) with today's technology (even scaled up) it will take a lot of time to change planetoid's orbit 3) after the collision it will be quite a while (perhaps millions of years) before the planet surface will become suitable for colonization. [Answer] Okay, I don't know if it can be considered "plausible", owing to the notion that even our best unmanned probes don't do well on Venus for any length of time, however using the *smallest amount of handwavium possible*, consider this: I propose that if we have progressed technologically to the point that Venusian solar shades in planetary orbit are possible, we likely also have materials suitable for ground-to-orbit deployment of a 'cable' maybe made of a yet undiscovered monomolecular fiber, capable of enormous tensile strength. Such a material could be used to anchor several (very large) cables, reaching from the surface to a low orbit, joined at the orbital end and attached to a system that slowly lifts the 9.2MPa surface atmosphere ( perhaps like a siphon) to a directed port that uses the atmosphere escaping to provide thrust in a low-thrust 'spinward' direction. The result would be a thinning of the atmosphere, and a slow but steady thrust that \*with time \* will affect the planet's rotation. I would advise however that since Venus does not have its own magnetosphere and relies on a solar 'envelope' of magnetism to deflect particles, thinning the atmosphere may produce undesireable results [Answer] It would take a loooooooooooooooong time, but you could put up a bunch of surfaces that were dark on one side, and reflective on the other side. Have the dark side face sunrise, and have the shiny side face the sunset(that's backward). Light hitting the shiny(dark) side would slowly increase the rotation of the planet. (information was based on conjecture and faulty memory, thank you for the correction JDługosz) <http://io9.gizmodo.com/5875747/the-light-mill-a-toy-that-shows-how-we-might-one-day-power-space-ships> [Answer] The atmosphere rotates faster than the planet, and is massive. But Venus has no intrinsic magnetic field. Instead, one is extrinsically induced by the interaction of the solar wind with the elements in the atmosphere. This is what keeps the atmosphere from escaping to space. Break that. Use airship drones in the upper atmosphere to alter the atmospheric composition enough to disrupt the extrinsic magnetosphere, allowing the atmosphere to escape to space until the rotation of the planet catches up to the atmosphere. [Answer] "In theory" you could give the planet a large moon and use the moon's orbit to impart more angular momentum to the planet, but this would take centuries, and tech that allows you to move a sufficiently large moon into a stable and mathematically correct orbit of your target planet. This would also likely cause massive tectonic issues for the planet, assuming the planet has a still liquid mantle and spinning core or whatever. If it didn't, I think there is a good chance you'd just alter its orbit, not its rotation, and/or the planet would break up under the strain. ]
[Question] [ **If animals were scaled up to be about the same size** in anthro form (human-size) regardless of species (i.e. wolf-people and hare-people both become man-sized as well as man-shaped), **would the ones that are more deadly in our world still be more deadly?** In most fiction with anthropomorphized animals, the general food-chain hierarchy of which animals are more deadly than others seem to still apply. Predator animals are still dangerous with their claws and teeth that are designed for hunting and killing, while former prey species are still generally not-so-deadly unless they resort to manufactured weapons. However, I would imagine that a great many creatures that are stereotyped as harmless in our world would become much more dangerous when scaled to match their peers. Even non-hunting creatures have powerful teeth and claws, and they would be even more so if greatly enlarged. Burrowing creatures like rabbits and moles, with their digging foreclaws, would probably be able to do some serious damage. Even flat-tooth herbivores, if as large as their enemies, would be able to do some serious biting damage. Small, fuzzy creatures in general may be weak when small, but a human-sized equivalent might have a good amount of muscle indeed. **How would the natural weapons of a timber wolf and a hare compare if they were about equally sized? How equalized would their teeth and claws become? How would their muscle-sizes and to-scale strength measure up?** [Answer] Let's start by clarifying: Herbivores are *not* weak by virtue of being herbivores. In fact, a healthy prey animal will almost always be able to either outrun or outfight the predator species that typically preys on it. Predators survive because they target the vulnerable members of a herd: the weak, sick, injured, or children. In other words, predators regularly kill prey not because of some inherent combat superiority of predators in general, but because *they choose which prey animal they will try to fight*. Some predators and prey are built for speed, others for fighting. If we remove size from the equation and throw a random anthro-predator and anthro-prey into a fight, the factors that decide which will come out on top will depend on how that species hunts or avoids being hunted. Which one is a predator species and which one is a prey species is more or less irrelevant. This question is somewhat unique, in that we are not simply scaling animals up or down, but altering their shape as well. The human body is good at doing human things, so anthro creatures will likely have some of their natural abilities reduced, and others increased simply by virtue of having a human body shape. In order to answer this properly, we have to establish exactly how anthropomorphized they will be. Will a mouse still have short stubby legs and a round body, even though this will make it hard to walk scaled up? Will a human-sized elephant man have the stiff, pillar-like legs that are so completely dedicated to supporting a full-sized elephant's weight that they are incapable of jumping? Let us assume that they have whatever shapes are needed to carry over their naturally outstanding physical capabilities. An anthro animal that would be strong for its size in its natural state will still be strong for its size. An anthro animal that would be fast for its size will still be fast; probably not *as* fast because the human shape isn't really optimized for speed, but still quick-footed. Popular lists of "world's strongest animals" are often inappropriately dominated by both very large and very small animals; big animals are often only strong by virtue of being big and small ones are typically only strong "for their size" due to the square-cube law. To establish which animals will retain their strength when anthropomorphized, you have to compare them to similarly-sized animals. Small animals like rabbits and hares are built for speed rather than combat, and anthropomorphized, that will still likely be the case. However, a wolf may not be the best choice of example for comparison when it comes to quick-action physical capabilities. This is because, for their size, wolves are not especially remarkable in either strength or speed. What they specialize in is, like humans, cooperation and endurance. So I would expect a human-sized anthro hare - a fast animal that *also* packs a literal kick - to win out over an anthro wolf in a one-on-one competition, whether it was a race *or* a fight. On the other hand, a wolf person will probably not try to tackle a hare person alone - they'll get their pack to back them up. And they will be able to hound the hare until it's out of breath. If you want an example of a creature built for fighting, the traditional King of Beasts is actually not a bad place to start. Lions, as well as jaguars, *are* extremely strong animals, even factoring in their size. There are some herbivores that might be able to tangle with the big cats, though, like zebras, which often opt to fight similarly-sized predators instead of fleeing. And of course, nobody messes with the badger man. Teeth, claws, hooves and horns can be good weapons for an animal, although they're pretty much irrelevant for a humanoid that can use hand-held weapons. [Answer] @Alexander von Wernherr comment to the original question is apt. Not only are prey animals adapted to avoiding a fight instinctually (generally speaking), but physically as well. A hare that was about 5' 10" and 185 lbs would have two big front teeth, and some claws, but most of that 185 lbs would be in its *massive* hind legs. A rabbit does not kick as part of its fighting. And here's one reason why: A rabbit's skeletal structure is overall much lighter compared to predators (because it is built for speed), and shatter relatively easily. Femurs sometimes break just from jumping. Fighting is not winning for a rabbit. Its eyes are set more to the side of its head with almost 360 degrees of view, but no binocular vision -- which is real handy when you are trying to bite (or punch) something, especially a moving thing. You can't just scale up things and get equal return for size. If you take the long, light and thin leg bones of a rabbit, and you make them even longer, and attach about 100 lbs more muscle weight to it, those bones may no longer be able to take the stress. The bending stresses may be tolerable when the bone is only two inches long, but if they are going to be two feet long, then the proportions and the density have to be beefed up. A good example is engines used before the Wright Brothers; they were simply not able to output enough power to carry their own weight. Bigger engines put out more power but they weighed more too. It also ate a lot more fuel and generated a lot more heat. A tiny engine is less likely to melt itself. That same engine fifty times bigger actually might. Making things bigger increases the advantages but also increases the disadvantages. A timber wolf, on the other hand, has every advantage. It is a sleek killing machine, not a fast grazing machine. However, even a 5' 10" rabbit could still kill you or a wolf if it got a lucky bite in. So size alone would make it more dangerous for the wolf, but all in all the wolf is built to kill, and a rabbit is built to run. [Answer] I cannot find anything usable for a good comparison of a wolf and a hare the size of a human. The closest thing regarding the bite is this article about the [bite force quotient](https://en.wikipedia.org/wiki/Bite_force_quotient), which might help you get an idea of how strong your wolf might be if he was human sized. Regarding fighting: hares can be seen having "boxing-fights" with each other. So I suppose in your case you could adapt some human martial arts to your hare. Because hares have very strong hind-legs something like kick-boxing sounds like an interesting idea for your hare. [This](http://www.todayifoundout.com/index.php/2014/03/differences-rabbits-hares/) source says that the North American Jackrabbit is faster than a grey wolf (40 mp/h). If you make your hare bigger he will be even faster. So you have a very fast fighter focusing on his hind-legs as a "weapon", but able to use his fists, too. Wolfs would normally hunt in a pack. Therefore your wolf might prefer an unequal fight in a gang against isolated targets. [This](http://www.todayifoundout.com/index.php/2014/02/bloggers-tale-said-blogger-decides-venture-doors-nearly-gets-consumed-wolves/) article says, that the bite of a wolf can be up to 400 pounds per square inch. This could also be used as a reference for your bigger wolf, although I am not sure how big this wolf should be. According to [wikipedia](https://en.wikipedia.org/wiki/Gray_wolf) a grey wolf can be up to 1,6 metres "long" and weighs up to 80 kg. Sounds like a human, if you can make him stand up straight. So, basically you have a very fast kick-boxer that would normally try to run away as fast as possible and a thug with an extreme bite preferring to fight in a pack. I don't think these two would fight, but if they had to the hare would have the advantage, as long as he is not bitten. Once the wolf lands a hit the hare is a goner. The claws of the wolf could be problematic too, but again, the hare might be faster. I hope this helps you with your idea. ]
[Question] [ Under the [Bretton Woods system](https://en.wikipedia.org/wiki/Bretton_Woods_system) the US Dollar was fixed to gold. ($35 would get you an ounce of gold if you were there.). This obviously created problems when gold became rarer and rarer; the American dollar slowly lost its value (this is what my books say). In my post-apocalyptic world, some amount of government and order remain in most regions albeit severely crippled. They have almost no good infrastructure or food resources. Obviously, under these circumstances, gold will lose its value because everyone will want bread more than the gold (am I right here?). So in order to combat this, much of the surviving world decides to peg its currency to agrarian produce. Such produce which is sparse and, in this environment, much more valuable than gold. Four questions: * How could I ensure that such a system would work? * How do I combat black marketing since agrarian produce is consumable? * How long could this system be stable? * Is it possible that given enough time this system becomes permanent? [Answer] Most modern currencies are [fiat currencies](https://en.wikipedia.org/wiki/Fiat_money). They function because they are backed by "the full faith and credit" of a major government and their *promise* that the money is worth something. When you have paper money backed by gold or silver, somebody takes a piece of note paper and writes "pay the bearer a pound of silver from my vault." If the person issuing the note is trustworthy enough, other people will accept that the note is worth as much as a pound of silver. (Initially it might be accepted only at a slight *discount*, especially at some distance from the person who issued it, to reflect the trouble of actually getting it exchanged. But paper is easier to transport, so it might be preferred to [specie](https://en.wikipedia.org/wiki/Bullion_coin) after some time.) At some point it becomes convenient to uncouple the paper from the metal. The person or institution issuing the bank note writes "this is a pound" onto the note, without a direct promise to pay silver. With the institution is trustworthy enough, that piece of paper is worth **something**. How much silver it buys may change at market rate, which is a convenient way to determine the value of silver. So there could be a bank note "pay the bearer a pound of grain" if the issuer has a large granary. This might work if there is not enough trust for true fiat money, but enough trust that the note will be redeemed. Something similar was done by Germany in 1922 to stop the inflation after WWI. The [Rentenmark](https://en.wikipedia.org/wiki/German_Rentenmark) was backed by real estate. *Side note: There are plenty of good reasons why currencies are no longer pegged to gold, and scarcity of gold is the least of them. It is quite inconvenient if the total value of currency is linked to the total amount of gold -- what if the economy grows faster than the gold supply?* [Answer] In the history of currency, nobody has ever eaten gold. Gold and dollar bills are always a means towards an end. Currency is valued because it can be traded easily. If you have a post-apocalyptic world, you may see the reintroduction of the barter system, which has a similar look and feel as to using produce as currency. However, as things grow, such produce is a poor currency. Produce is not the best form to store value in. Economists generally recognize three major factors which make a currency useful: * Hard to forge - You want your currency to appear to have a reliable value. This is related to your black-market question. If it's hard to distinguish fine quality maize from low quality maize until you cook it, you'll find that would open the door for a black market, and would make that product a bad currency. * Fungibility - You want your currency to be easily divisible. Many produce products are fungible, but not all. A head of lettuce can be split in half. A coconut is harder to divide evenly. * Durability - This is where many produce items fail as currency. You want your store of value to be able to survive long enough to spend it. Lettuce wilts, and tomatoes go bad. Grains do reasonably well for durability from year to year. Potatoes are actually really promising here. In Peru, they perfected the art of drying potatoes. The particular potatoes and the way they do it actually leaves these particular potatoes replantable next year! Note that nowhere on there was "high value." If a currency has all three of these, it generally does well. Pennies are just slugs of copper... or were slugs of copper until we made them even less valuable. Yet they're still a successful currency. We've tried for years to get rid of them (it costs 5 cents to make a penny!), but they stick around! Eventually people will choose objects which meet these three criteria for their currency. They may accept two-out-of-the-three for a short while, but once they get on their feet, they'll want all three. There's only one case I know of where agricultural product was used as currency, and that was the Inca. In their civilization, cocoa beans were used as a currency! A fresh rabbit was worth 2 cocoa beans, according to one document we've found. Cocoa beans were hard to forge (everyone knows what they look like), fungible (at least to the rich... the rich could afford to have enough cocoa beans to treat them like coinage), and durable (cocoa beans last an astonishingly long time when properly treated). This was a consumable currency, like the famous cigarettes in POW camps (non-smokers would still accept cigarettes as payment because they knew there was a smoker they could sell them to). Of course, it takes a lot of cocoa beans to make a cup of hot chocolate. The poor could not afford such an exotic drink, while the rich could literally drink away their money! [Answer] Japan currency used to be koku - enough rice to last for one person and one year. So yeah, it's been done and it worked. [Answer] One of the reasons for using commodity backed currency such as silver and gold was that the metals themselves had intrinsic value, and were fungible (gold and silver are generally considered valuable anywhere, ancient Roman coins have been found in large caches as far away as Siri lanka). Metallic currency is also compact (a pocket full of coins is far easier to deal with than the object you are purchasing) Produce has difficulties in that it is not as fungible (not everyone actually likes to eat what you grow), difficult to transport and is perishable as well. When produce was used as the backing for currency (such as community grain silos) there was always the issue of the materials stored in the silo going bad, being eaten by rats and insects, accidentally destroyed by a fire or deliberately destroyed or stolen by invaders or criminals. Metallic currency does not suffer from most of those fates. So this sort of produce backed currency could work over a limited area and for a short period of time, but the extra overhead will make the currency difficult to use ({imagine the disputes when you put 3 bushels of grain in the community pot but after spoilage etc. you only got two bushels back). There could be an evolution from agricultural produce to backing the currency with productive agricultural land (and the value and amount of currency could evolve as land is cleared or improved), but once again there will be a limitation to the area where the currency could be valued 9much like you van't cash your grain backed coins at someone elses silo, you are not going to use currency where the vendor isn't in a position to buy or sell the land that backs the currency). The one widespread produce backed "currency" which did exist in history was Cypriot copper ingots cast in a stylized oxhide. Traders could go throughout the Bronze age world and everyone understood the value of the ingots in barter terms (one ingot was worth one Ox. how well you could barter the value of an ox defended on the skill of the trader). However, the reason this worked was more due to the value of copper (the intrinsic value theory) than anything else. [![enter image description here](https://i.stack.imgur.com/oZK2B.jpg)](https://i.stack.imgur.com/oZK2B.jpg) *Oxhide ingots* [Answer] > > Such produce which is sparse and, in this environment, much more valuable than gold. > > > The rule is stated [bad money drives out good](https://en.wikipedia.org/wiki/Gresham's_law). So if you have one form of a money that is more valuable than another, people will tend to trade the *less* valuable money (gold) and hoard the more valuable money (food). In this case, they will also eat it. And farmers will grow more. This would persist until food became abundant again. In the circumstances that you describe, food would be very valuable. People would accept it in trade. It would be possible to create a currency based on promises of food. So you could go to an approved store and exchange your currency note for a day's food in some staple form (e.g. a bag of flour). There would be some challenges though. If farms produce an abundant crop next year, there will be inflation. Other goods will be worth more of the currency (i.e. prices will go up). If there is a problem growing food (bad weather, pests, disease, etc.), there will be deflation. Other goods will be worth less of the currency (prices will fall). The government would have to store food to make this credible. But since food has a limited shelf life, this means that they will have to constantly replenish this storage. Releasing food in the spring. Throwing away food in the summer (perhaps feed it to cows or pigs). Buying food in the fall. A normal year should have a surplus. An exceptional year should have a big surplus. A bad year should just make ends meet. [Answer] **TL;DR:** I try to come up with a 'sensible' scheme to peg currency to produce (taking into account some concerns voiced so far) and find a few of it's limitations. **Defining the Currency** 1 groin (portmanteu of "grain" and "coin") buys the calories and protein to feed a hard working, fit adult for a day, all in plant-based, easily stored form - most likely grains + lentils or something. Most likly definition is x calories, y% as protein. Protein content and caloric value are not too hard to measure. There may be a fee for analysis etc. at the grank (granary/bank) when you bring your produce. Expect a large body of codes on quality and quality control for stuff allowed into the granks. That means that one will suffer malnutrition if subsisting solely on the groin-backing foods (possibly little fat, hardly any vitamins). **Enforcing** The state, warlord or whoever collects a head tax in groin - meaning everyone must either get groin (for produce) from the central grank or work for payment in groin. This ensures that the grank is always well stocked. **Cash crops** There will be, in any given climate/region, one combination of produce that is most groin-efficient - bringing most groin/hectare and year. On the other hand, people like to eat a variety (and likely die on a groin-only diet) so we will also see people growing vegetables and other less groin-efficient foods. These, as well as meat and dairy products will be traded in groin but not via the granks. The actual daily expenditurey for food will be several groins for everyone but the most destitute. **Complications** A specific grank will store a variety of grains and beans and so on. The baker will have to go through these steps to make a bread: * Buy an assortment of grains and beans and so on for his groin, the assortment represents what's stored in the grank at this time * Sell everything except one very specif type of grain because our baker needs wheat with this exact glutene content for his bread, and no barley or soy beans or whatever else is in the mix of the day * Have the grain custom milled for the specific recipe Maybe the grank will have a produce-trading house attached so step one and two can happen virtually. You could imagine trading 'virtual grains' - that are still stored in the grank but at the moment don't back any groins. The size and handling of the virtual grains market will influence how much trust people put into the granks. Nothing lasts forever, so the grank will sell food that sits on it's shelves the longest or is most perishable otherwise. This gives the grank master quite some economical power if ther's any leeway. **Limitations** There will be only as much currency floating about as the grank stores foodstuff. A society on the brink of starvation will have hardly any liquidity. OTOH, to have a lot of capital floating about you need huge granks. How huge? I'm too lazy to do proper research right now, but for an estimate find these numbers: * How much of a given currency is floating about? (*X*) * How much is a groin approx.? (*y*) * How many people are there using the currency exclusivly? (*n*) Then X/(y \* n) is the number of days of food storage you need to back your currency. *My guess* is that at one point the amount of food storage becomes ridiculous, so nothing resembling late capitalism as we know it will be possible with such a scheme. Not having researched how long grains keep, I guess about 10 years at most - that's maximum ~3600 groins per person in circulation - remember, each groin has to be backed! **Conclusion** I could imagine a post-apocalyptic warlord coming up wit such a scheme when consolidating his litle empire: It encourages food storage at the granks which gives the warlord an additional lever over his population. Maybe our warlord is a goldbug but there's not enough gold (or similar) in reach to back a currency, and neither warlord nor subjects trust fiat currency? So we have a motive to start such a system, if our society continues on a capitalist trajectory the groins and granks will end at some point and in between we have a few weird effects. Now write your story. [Answer] **Non-perishable, commonly-locally grown calories, one adult's basic ration, e.g. 1 kilogram of dried soybeans (or closest high-yielding local bean cultivar.)** In the specific circumstances you specified, I suspect that a day's basic ration, especially of a non-perishable, general foodstuff (such as dried beans or grain), would become a natural unit of exchange. Or a week or month if a larger denomination is desirable. While neither as compact or durable as coinage metals -- it's what they can produce locally that has both immediate and future value -- both to survive and to trade. Once you're out of the starvation/food-shortage phases, people would probably move on to a different unit of exchange for trading. (But what 'currency' comes next, although an interesting question, likely depends on the details of the particular apocalypse. Vitamins, seasonings for basic foods like beans and peas?) From what I've seen, dried beans keep longer (quite a few years, if kept properly dry and sealed) than grains and can be eaten (e.g. boiled) without milling. Most grains (corn excepted) need some level of milling before easy consumption; IMHO that makes most unmilled grains problematic as the basic 'currency.' Even 'brown' rice (as sold in the USA) has had most of its outer/bran coat milled off. Where milling isn't available (or is expensive), an easier-to-consume foodstuff would IMHO be a better unit of exchange. There will likely be rates of exchange between beans (or whatever the baseline foodstuff is) and other common foods. Let the markets adjust according to supply and demand. ]
[Question] [ Age varies vastly even in just the vertebrate world, from the 2 years a rabbit has to the over 170 year old Seychelles giant tortoise, who is still going. Obviously, Lifespan will determine population, cultural views on age and most importantly, the amount of knowledge a person can learn and teach. Is there a method to figuring out the Lifespan of a species? Perhaps related to their metabolism or their activity levels? [Answer] Life span directly relates to body mass and metabolism. Each creature (I'll attach conditions in a moment) gets about a billion heart beats in its life. For smaller creatures with high metabolism, like sparrows and rabbits, this means a very short lifespan, sometimes only a few years. For larger animals with slower metabolisms, like tortoises and elephants, this means a longer lifespan, sometimes over 100 years. Interestingly, chickens and humans are big exceptions, each of them having double the average number of heartbeats per lifetime.[![Heartbeat chart](https://i.stack.imgur.com/Brmub.jpg)](https://i.stack.imgur.com/Brmub.jpg) So the question is: How big and how fast? If your species is small and moves rapidly, then their lifespans will probably be in the two-to-five year range. If your species is big and slow, look in the 70-to-120 year range. With that in mind, remember that age does not the species make. With a shorter life, the individual has a higher rate of living, by which I mean that everything happens faster. A rabbit matures much more quickly than does an elephant, but both have comparable percentages of infancy- the percent of the individual's life that it spends in infancy is comparable betwixt the two. You might have a species that lives only a year, but you can still write a coming-of-age story. Likewise, you might have a species that lives for a century and a half, but you can still cover all its life in one book. The trouble arises when you try to apply human time scales to non-human creatures. Take an extreme example, a species with a lifespan of ten minutes. Within ten minutes, an individual is born, lives, breeds, and dies. You could write a novel about the individual, just as you might about a human. There could be legends of a time, many many generations ago, so long ago that it is almost forgotten, when the world was dark, and there was no light anywhere (night-time) or when all the world was blazing with light (day-time). It all depends on the time scale, which I assume will be on the scale of the species whose lifespan you are trying to calculate. As long as your time scale matches your species lifespan, it really doesn't matter, other than stuff like seasons passing or the landscape changing. It's all about percentages and perceptions. [Answer] ## 1.5 billion heartbeats. Smaller animals - like a mouse - have faster heartbeats, and have shorter lives. Larger animals - like elephants - have slower heartbeats, and have longer lives. As a young nerd, I once saw a nature documentary that used that as a rule of thumb for the typical natural life of an animal. Unfortunately I don't recall what documentary this was, so I can't cite a reference for it. There may also a caveat, like it applying to land-mammals only. [Answer] I will look at this from a single aspect. There are other aspects which I cannot comment on. My aspect is adaptability. If the environment is hostile and ever changing, your species should have shorter lifespans to allow rapid evolution. In a more stable environment they can live much longer. Thus if elves are to survive, they should have perfect environment and they should be resistant of virus and bacteria. Otherwise, a virus can wipe out significant portion of the population and re-population would take time and another disaster might completely wipe them out. [Answer] If you want to find out the potential age of a species, you might look to finding out the [Hayflick Limit](https://en.wikipedia.org/wiki/Hayflick_limit "Hayflick Limit") for the species. This theory determines how many times a cell can replicate before it effectively dies. This ultimate cell age correlates roughly with the lifespan of the species involved. Obviously, this gives you the lifespan of a species in test-tube conditions and environmental factors have to be taken into consideration - especially in predator/prey scenarios or non-temperate climates. ]
[Question] [ In the book The Host by Stephenie Meyer, a parasitic species (Souls) attach to the back of the spinal cord of alien creatures to control their brains, but I find this a wee bit unbelievable. As it is unlikely that a wide range of aliens would have a spinal cord, what feature of the nervous system is likely to be found across a wide variety of alien species? [Answer] First of all, this is not science fiction. Read up the life cycle of the sheep fluke, which at one stage takes over the brain of an ant to ensure it can be eaten by a sheep. Currently, there's a journalistic panic about toxoplasma in undercooked meat taking over human brains to make them turn themselves into cat food (I kid you not). This sounds like something made up by the soybean industry. But to get to the point: * Some alien animal life is certain to develop bilateral symmetry. This is a winning design on earth, and has arisen independently among insects and vertebrates. * Bilateral symmetry requires a segmented body, each segment having a specialized function, with its own neural controls. * The front end must have sensory organs, if only to find food. * Sensory organs require neural coordination and control. * This predisposes to the development of an important neural collection at the front end. * This collection will have to communicate with the rest of the body, if only to keep it moving towards the food. * This means that nerve tracts will have to extend from the front backwards. * If this animal lives on a planet with minerals, it will develop a skeleton, if only to segregate the minerals it can't use and can't get rid of. And which planet doesn't have minerals? * This skeleton will evolve to protect the squishy nerves. * So rather than being unlikely, a spinal cord with a bony shell seems almost an almost inevitable feature of a sufficiently complex organism. Of course, we also have asymmetrical animal life forms on earth, the most successful being the octopus. But having no skeleton, the octopus is confined to the sea, leaving the land free for those other animals with the spinal cords. [Answer] Trying to get a handle on this question, I took a look at Wikipedia to see [what a nervous system actually does](https://en.wikipedia.org/wiki/Nervous_system): > > At the cellular level, the nervous system is defined by the presence > of a special type of cell, called the neuron, also known as a "nerve > cell". Neurons have special structures that allow them to send signals > rapidly and precisely to other cells. > > > It **sends signals**. That is the truly universal part. > > They send these signals in the > form of electrochemical waves… > > > **Electrochemically**. While that aspect is not absolutely essential, surely this method is likely to be among the fastest sorts of signalling that could evolve in a physical body. "Electrochemical signalling" is the closest thing I can offer to an answer to your question as currently formulated. However I think your question may include an overly-limiting assumption. > > …traveling along thin fibers called > axons, which cause chemicals called neurotransmitters to be released > at junctions called synapses. A cell that receives a synaptic signal > from a neuron may be excited, inhibited, or otherwise modulated. The > connections between neurons can form neural circuits and also neural > networks that generate an organism's perception of the world and > determine its behavior. > > > **Junctions. Modulations. Connections.** All of this is where [Information Theory](https://en.wikipedia.org/wiki/Information_theory) meets [Neuroscience](https://en.wikipedia.org/wiki/Neuroscience), neither of which I know much about. But, along with the concept of signalling itself, isn't *information processing*, rather than any material property, the rock-bottom essential property of consciousness that the Soul or other [*Invasion of the Body Snatchers*](https://en.wikipedia.org/wiki/Invasion_of_the_Body_Snatchers) type of mental parasite (or [demonic possessor](https://en.wikipedia.org/wiki/Demonic_possession), or [Granny Weatherwax](https://en.wikipedia.org/wiki/Granny_Weatherwax#Powers)) must hitch on to? So as well as, or instead of, a physical form, our parasite/symbiote exists in… er... *information space* or something and… er… OK. That's really lame. But something like that. As the first paragraph of the excellent [answer by "frank"](https://worldbuilding.stackexchange.com/a/41206/9207) above says, real life evolution came up with something as [weird](http://www.damninteresting.com/a-fluke-of-nature/) as the lifecycle of the various sorts of fluke. Perhaps if we could describe how a being would **evolve** to take over the bodies of multiple drastically different species from different planets, we would be able to better theorize on how exactly it does it. [Answer] Likely to be found across a wide range of "animal-like" species: a central controller and head comprising a sensory cluster and feeding orfaces. The "brain" needs to send and receive signals across the rest of the body. A central cord might not be the only way to do it: look at a starfish or octopus. There have been discussions here about multiple brains or distributed systems. But they still connect to each other and to everything else. **same:** signal distribution with a hub. **don't assume the same:** the single-run topology. **same:** some kind of cables carrying signals. **variety:** how they work. Will your mechanism be able to tap in? [Answer] It depends on the type of planets that the aliens come from. If it the planets are similar to earth then having alien creatures with spinal cords is likely, as most creatures on earth have spinal cords. Having read Host I don't think that they (Souls) only inhabit creatures with spinal cords. Wanda talks about living in a "seaweed" type creature. The souls probably have multiple ways of talking over a creature's body. Attaching to the spinal cord is just the way that they take over human bodies. They probably use a completely different way when dealing with other creatures. [Answer] Unfortunately, aliens being alien, there are so many possible ways that signals could be transmitted around an organism that the souls couldn't realistically have a hope of being able to interface with them all. One might use electrical, the other might use chemical, the third might use light, and so on. The souls are a scientifically implausible species. Magic must be involved. ]
[Question] [ **What would, roughly, a scientific research station look like on a gas giant?** Use Saturn as a baseline. The station would float because of a "balloon" carrying nothing. Vacuum is the lifting "gas", as the atmosphere of most gas giants is already hydrogen/helium. The pressure at the average elevation of the station would be 1 bar, or just a tiny bit less than 1 atm. The average temperature would be around -139 C. Power is generated by fusion of atmospheric hydrogen and helium, as Saturn is too far away from the sun for solar power to be meaningful. The stations will be floating along in the wind, so they will experience a stiff breeze at most, because they aren't actually going that fast relative to the wind. Materials come from regular shipments from drop bots delivered by mass drivers in the asteroid belt/moons. (I haven't decided yet) Drop bots are large machines that are mainly cargo pods built to withstand atmospheric entry, with helicopter blades that extend when they slow down enough. 23rd century tech, use your best judgement. Some ideas I had, might not be the most practical: Would it have a huge central sphere with the station built on a strip around its center? Would it be a number of small balloons around the edges of the base? I feel like that'd be sacrificing buoyancy for redundancy. [Answer] ## Maintain altitude using a heated gas envelope, much like a hot air balloon on Earth While it's true that a vacuum is much less dense than atmospheric hydrogen at 1 bar, the pressure vessel/flight envelope required to maintain buoyancy adds unnecassary weight. The primary problem with a "lifting vacuum" is that there's 1 bar of pressure pushing inwards on the envelope but nothing pushing back out. Thus the envelope alone must withstand a uniform 1 bar of compression plus fluctuations in atmospheric pressure plus wind loads plus safety margin for unplanned ascents or descents. While doing this is probably possible, I believe there are easier ways. ## Heat the Hydrogen Instead of creating a hard vacuum, use a gas envelope to contain heated hydrogen. Getting heat is both easy and essential. Since fusion power is available, heated hydrogen is abundantly available. As opposed to a hard vacuum in the flight envelope, filling it with heated hydrogen does a couple of beneficial things. * It gives shape to the envelope as well as structural integrity. * It prevents ammonia ice build up. Just as water ice build up on airplanes causes significant problems, so would the build up of ammonia ice cause problems on the surface of the space station. If the envelope is heated above the melting point of ammonia ice then no ice can accumulate. * If the shape of the envelope is variable then inflating or underinflating parts of the envelope will allow the research station some degree of mobility. * An envelope that must only maintain tension loads can be made much much lighter than a structure dealing with compression loads. This is the same difference in "lightness" observed between suspension bridges vs older stone bridges. We want this envelope and the associated research station to be as light as possible. * In the event of reactor failure, the residual heat in the envelope will give the scientists/engineers on the research platform time to solve the problem before they lose buoyancy. ## Envelope Constraints The envelope should have the following characteristics: * Volume: Sufficient to maintain station buoyancy at any altitude between 0.1 bar and 10 bar. This gives an altitude range of just above the water ice clouds at the bottom of the troposphere all the way to the top of the troposphere. This should include a 50% safety margin on envelope volume. Being able to fly to 0.1 bar means that rendezvous with incoming supply ships can be done above the clouds and using visual flight rules instead of instruments. Being able to see where you're going is always preferable. * Abrasion resistance: Even thought the relative winds experienced by the station should be relatively small, ammonia ice and ammonium hydrosulfide ice may be abrasive. Over a long enough period this could cause the envelope to lose pressure and fail. While upwellings of water ice air are uncommon, the envelope should be able to handle exposure to water ice crystals as well. * Chemical resistance: I'm unfamiliar with the chemical properties of the three ices in Saturn's atmosphere but the envelope should be able to resist these effects as well. * Redundancy: Should the envelope fail causing an unplanned descent into Saturn's atmosphere, a back up envelope will be very handy to have. This should be inflatable in fairly rapid order. ## Station Constraints The station will be positioned at the bottom of the envelope for stability's sake. Aside from the envelope, the research station has the same concerns as a space station with the reduced requirements for cooling. However, there are a couple of things to mention. * Redundant Power Supplies: With this design, heat equals life, both for the envelope and for the human occupants. It is therefore essential that the fusion powerplants be online at all times. * Hydrogen Processing: These will need to run all the time, preferably with multiple units running at the same time. Sulfur can be discarded back into the atmosphere. Excess hydrogen can be stored in the envelope or low pressure tanks on the station. Nitrogen can be used to supplement the station's atmosphere. * Oxygen Processing: The station must be able to position itself low enough in the atmosphere to gather water ice. This provides infinite oxygen supplies. All other metals will need to be delivered from off-world. [Answer] If I were designing it, I would have a large rectangular block (think two or three Borg Cubes squeezed together) as the main body of the station. This block is supported by several "balloons" around the upper rim. The weight is below the buoyancy source, so it will be more or less stable. To add some extra stability, underneath the block have a large pool of water with a massive floating weight in it. This weight will act as a counter-balance; should the station start to tilt, the buoyancy of the water will cause it to move "up" the tilt, adding weight to bring the station back to level. Note that this will add lots of weight, so you will need extra balloons to compensate. But if there's one thing you learn in engineering, it's that redundancy is better than failure. [Answer] Let's look at some of the difficulties your gas giant research station will need to deal with. To start with, let's take a look at the idea of using a vacuum balloon. 1 bar is equal to 0.1MPa. Using the formulas supplied by [an answer on physics.SE](https://physics.stackexchange.com/a/35246/79374) about pressure in a sphere, the formula for the required thickness of the sphere is $t = p r / (2 \sigma)$, where $\sigma$ is the compressive strength in MPa, $p$ is the pressure (0.1MPa), and $r$ is the radius of the sphere. The mass of the shell is roughly $t\times 4\pi r^2\times\rho$ where $\rho$ is the density of the material. [Using 0.19kg/m^3](http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html) as the density of Saturn's atmosphere at that point, we get $0.19\times \frac{4}{3}\pi r^3$ kilograms displaced by the sphere. Combining these formulas, we can get the mass of the shell as a function of the compressive strength and density of the shell material and the radius of the sphere - $0.4\pi r^3\rho /(2\sigma)$. Now let's look at the ratio of the mass of the sphere to the mass of the atmosphere displaced - $\frac{0.4\pi r^3\rho/(2\sigma)}{0.19\frac{4}{3}\pi r^3}\approx \frac{3\rho}{4\sigma}$. Fortunately for us the formula has managed to simplify quite nicely. In order to float, this ratio needs to be less than one - it needs to displace more mass than it weighs. This could be reached by a hypothetical material with a compressive strength of 1MPa and a density of 1kg/m^3. Unfortunately, this isn't good news for the vacuum balloons. Steel has a compressive strength somewhere around 300MPa, but has a density of about 8000kg/m^3. That leaves the ratio at about 20, nowhere near being able to support even itself much less a research station. The shell could be thinner by using internal supports, but even then you wouldn't be able to get an over 95% reduction in the total amount of steel being used. Also, you'll notice that all radius contributions cancelled out in the final equation. This means that making the sphere larger or smaller makes no difference. A hot-air balloon really is the way to go. Unlike needing something that will resist compression, like steel, you can use a more flexible material with a high tensile strength, like kevlar or graphene. Graphene has a ridiculously high tensile strength, but by itself it's not airtight. It's quite reasonable that by the 23rd century we will have developed either a graphene-like compound or something that we can coat graphene with to have a strong, lightweight airtight material. From there, just follow @Green's answer. It's pretty much what I was going to say. [Answer] **If it was on Saturn** Rockets, blimps, spaceships, hell even one of Davinci's flying machines. Since the air is mostly comprised of Hydrogen the air wouldn't combust, but it all depends on what you would like specifically, and what type of future you are thinking of (steam punk, cyber punk, etc). ]
[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/29455/edit). Closed 8 years ago. [Improve this question](/posts/29455/edit) Something I'm working on: An alien culture has developed teleportation to a certain extent, enabling them to move personnel and equipment. What can I do to avoid making it too easy for them to, say, teleport a WMD into their enemy's backyard? [Answer] Quite simple - require a transmitter and a receiver, and make the machinery big and obvious and power-hungry. This would preclude teleporting an object to a place without a receiver. They would have to take a receiver there first. If their enemy had a receiver - perhaps they were friends but fell out - then I would also incorporate the capability to block senders. No doubt such a complex device would require an electronic handshake before doing its thing, and if the wrong sender ID came through, or a correct one came from the wrong place, then the transmission could be refused. [Answer] Perhaps they can only teleport to another teleportation device, which requires a facility and large energy reserves? That would limit them to areas where they are well established. [Answer] If this isn't a "wormhole" device, then most teleportation requires the object to be broken down at the transmitter, and reassembled at the receiver, with only high quality information passing between the two. Ironically, this means most WMD would be conceptually *easier* to teleport than complex machinery or computer chips (most chemical agents are "binary", so you simply ship two containers of only moderately toxic stuff and have them come into contact when you want to activate the weapon. A cup full of bacteria or virii would also be relatively simple to send. Even a "Hiroshima" bomb is relatively simple to construct, once you get access to the materials). The safety mechanism would simply to restrict the types and amounts of materials available in the storage chambers of the receiving units. It would be hard to teleport a nuclear weapon if no fissile material is held in the receiver, for example. Chemical weapons could also be stymied by keeping the receiver free of volatile chemicals like chlorine or fluorine (or compounds containing them, since the receiver can presumably disassemble materials to get and rearrange the atoms it needs). Even if Dr Evil has cleverly encrypted the "message" going to the receiver, if the elements needed are not there, it isn't going to be made. The only weak point is that the chemicals needed for life and organic materials are relatively cheap and common, and it would be hard to tell without some serious computational power just what that strand of DNA is supposed to give rise to: a Bollywood supermodel or a super virus? A total ban on teleporting organics will need to be enforced (and once again, ensuring the amino acids for DNA are not in the receiver for assembly is the fail safe). [Answer] If they have teleporting tech, they should have scanning tech that can detect explosives, bioweapons, etc. Look at an airport, now advance the tech a few hundred years. Could auto-filter hazardous materials, although this could still allow mechanical weapons or robots/androids/cyborgs that could disable safeguards. Could make receiver have to confirm incoming object after scanning but while in a buffer, before rematerialisation. Copied from comments By requiring a receiving teleporter, it removes the ability to teleport anything or anyone to any location that doesn't have a receiver. It would prevent an attack by using the teleporting tech. Without requiring 2 stations, then depending on where you were attacking, you could teleport vital equipment from the other location, such as cooling systems, valves, monitoring equipment or personnel, or teleport something into a place where it would do damage without it being a WMD. What do you think would happen if you were to teleport an object into a coolant pipe & also into the shut off valves? [Answer] Make it require a lot of energy, and take more the farther it goes or the more mass it has. [Answer] Make it possible only to teleport organic materials. This way humans couldn't transport weapons and clothes would need to be wool or cotton. Living beings would get sick from the transport, sometimes throw up upon arrival (equivalent to summoning sickness used in some games) making surprise attacks from untrained people close to impossible. Of cause nothing is foolproof, organic materials could be sent through mixed up and go boom. But as far as i know few WMD's exists that contains only organic materials. I guess biological warfare would get a step up. But as in most weapons race, so would the protection, antidotes, gas masks and so on. ]
[Question] [ Basically I want to create a world in which some of the humans have developed a higher body temperature in order to survive cold, harsh climates, such as the poles or even tall mountains. The reason behind it is rather selfish: I just want them to be a sort of barbarian like nation wearing skimpy outfits, something along the lines of Tarzan (please do not dwell on this aesthetic aspect though, just the scientific implications). I know that the human body goes into heat stroke at temperatures of over 40 degrees Celsius/107 degrees Fahrenheit, but I was wondering if there's any way for it to evolve to overcome that. How would that affect a human being's appearance? Would they need a better vascularized skin, maybe a larger heart? Would this have any impact on their height or muscular development? I was thinking about the fact that an increased pilosity could help them maintain body heat better, but the idea of ape-looking humans does not appeal to me. Perhaps they could have a thicker skin instead? Also, I want my evolved humans to be mostly hunters, so quite active, therefore I need to know whether this increase in body temperature would have any impact on their diet as well. I remember reading that monks in Tibet can increase the temperature in their extremities (such as hands and feet) by up to a third in order to prevent frostbite, but the explanation for that was meditation. Obviously my frost barbarians won't have time to meditate, so I was thinking of a more permanent solution. [Answer] The answer to this is simpler than you think: don't make their body temperature special at all. Consider that you don't have to raise core temperatures at all. In fact, it's not really all that helpful. The difference in temperature between the core and the outside environment is so monumental, that raising body temperature doesn't help all that much. Consider: the average winter temperature in the arctic is −30°F. The human body is [98.6° F](https://en.m.wikipedia.org/wiki/The_Man_Who_Sold_the_Moon), round up to 100°F, there's a 130°F difference between the outside and the core. Now, lets super super super charge our humans, so that instead of operating at 100 degrees, they operate at 135°F (the highest recorded land temperature ever). Now the difference is 165°F. Going from "normal human" to "ridiculously hot" only bought us a 22% increase in thermal flux! We can, however, change the distributions. The core is always the warmest part of the body, and the body gets colder as you approach the extremities. Humans have evolved to keep the core warm, and we so by cutting off blood flow to regions that get cold, basically sacrificing their warmth so that the core can stay warm. In fact, we can cut blood flow to the skin to *almost zero*, in environments of extreme cooling ([source](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2963327/)). Its the cutting of the blood flow that allows things like frostbite to happen. Once we cease to warm up a body part, it begins to drop in temperature far more rapidly. If your Barbarians simply adjusted this process so that they didn't engage in as much vasoconstriction due to cold, they'd *easily* keep their toes and fingers from freezing. This would be the non-meditating version of what the Tibetan monks do. Humans have evolved to be efficient with our energy, and our cold response is part of that. If you don't care about efficiency at all (no known species on the planet), or you can be very active and use waste heat to stay warm, there's no particular reason you need any special core temperature or weather gear. Just make sure the heat gets to the outside, and you wont have any trouble at all. [Answer] **TL;DR: NO!** This is a case of 'you can't get there from here' evolution - at least in any realistic sense. 'Cold-blooded' creatures such as lizards and frogs have many different proteins that do each task, each operating optimally in a different temperature regime. However, with the evolution of homeothermy, a particular temperature was chosen, and the DNA coding for the now-irrelevant proteins was lost. A frog cell's DNA is far longer than a human's for that reason. The problem is that to evolve proteins that can *all* operate in a higher temperature regime is quite difficult, whereas to simply select the right proteins from an existing set is far simpler - except that humans no-longer *have* those proteins, *or* the DNA that codes for them, but reptiles and amphibians *did* - and still do. **The Alternative:** The solution to your problem - scantily-clad barbarians in a cold climate - is actually simpler, and could well add to your desired trope: Make them big. *Really* big, say seven to nine feet tall and four or five hundred pounds, with masses of muscle covered by a good padding of fat. They wouldn't look like Arnold Schwarzenegger, they'd look more like big wrestlers or weight lifters. The advantage of this is described by the square-cube law. More volume in total means less surface are per unit volume, thus reduced heat loss. In addition, having a more active metabolism would mean that they'd be producing more heat, and they'd be able to allow more blood to flow through their extremities in cold weather, thus greatly reducing the chances of frostbite. In fact, wearing too many clothes would be uncomfortable for them, especially in warmer climates - they'd be at risk of overheating. On the downside, being this big and having this high a metabolism would require a lot of fuel, and we can expect our big, muscular barbarians to be big eaters too. Fortunately, the meat that they hunt is a good source of energy and protein, both of which they'd require in abundance. [Answer] Increasing body temperature only means you'd lose more heat to the outside. It won't increase your survival odds. What you want is *faster* circulation, as in more beats per second and better insulation. In land animals, gap between individual hairs traps air to prevent heat loss. The other way around that is to have air pockets trapped in fat as in whales or large deep sea animals. So, your options are: hairy barbarians, fairy barbarians (feathers), or flabby barbarians. ]
[Question] [ There is a planet that is full of underground caves. Some are narrow and long, others, go on for miles and are wide enough to contain entire cities. However, all of these caves, are completely dark. One organism, commonly grows to cover just about every surface. It nourishes itself off the heat of the planet and the water which has been endlessly falling through the tunnels, and acts like a cooling system for the interior caves, whereas the surface is a scorched, barren wasteland that is unable to support any type of life. This organism tends to spread any excess water it encounters to its neighbors, resulting in cavern surfaces that are essentially covered in a film of material that helps reflect any sounds from the various lifeforms that inhabit the caves. One particular species, called species "A" is not all that different from us humans. They started as simple caretakers of a certain plant. This plant could easily grow in the conditions of the caves, but they tended to consume large areas of space. One plant could grow to encompass the area of a football field, and the pollen it produced would be packed and stored by the A into structures not unlike a bee's nest. However, the plants generally killed the organisms mentioned above, and required the water that they spread, so the A needed to depend on multiple plants, carrying and moving the offspring to new locations after successful harvest (*and accidental pollination*). The long time the plant took to grow meant that the A spent a lot of time in a migratory pattern - starting new plants and then returning across vast distances to harvest the older. Unfortunately, the A also tended to compete among themselves, and also had predators to deal with, along with other animals either trying to eat the plants, or break into their homes. They could escape many larger predators by hearing them and escaping into smaller tunnels, but smaller threats required some thinking and experimenting with a variety of tools. In the end, certain chemicals were found to be highly harmful to most underground creatures, along with certain rocks which, after being rubbed together, could create an incredible heat that ate some materials(*fire*) - even away from caverns devoid of any cooling organism. From here, they managed to continue making processes and ideas simpler and more effective. They learned how to construct better and plan more effectively, as well as develop defenses for any opposing A's that may try to steal their food. While developing into what would be humans' [Renaissance Era](https://en.wikipedia.org/wiki/The_Renaissance) they discovered a new environment. The temperatures here were not as severe, making our previous organism unable to grow. Instead, there were tall, centrally located plant spires which stored water and gave off a strong bio-luminescence, enabling many creatures in this area to develop eyesight, which is a rare feature on this planet. In this area, sounds could be heard, even with their reduced hearing (*from lack of the cooling organism spreading across everything*) and they knew things were out there - yet they seemed unable to catch any of these strange creatures, or even get close to them. They were considered ghosts, or spirits, and A's rarely went into the area, especially because of how much their hearing ability was reduced - making them feel as if they were just bumbling about in the dark ;) --- I'd like for the humanoids to somehow discover that the other animals are using sight in the manner that our humanoids use sound in their own caves. What is the earliest and most likely way (*starting from the technology level of the Renaissance Era*) that our humanoids would be able to discover that the animals are using a different method of detection (*sight*), and then successfully accomplish catching one of these animals? [Answer] A sightless race would have become more in tune with their other senses to allow them to hunt and to farm successfully. If you can hear where an animal is, and you can recognize it by the sounds it makes and you can throw a spear at a lethal spot. Or lure it into a pit trap you have dug. They would have devised techniques. The hunters who are first into the new terrain with the sighted creatures would first notice the difference in the animals. They would sound different. Probably have louder footfalls compared to sightless animals. Yet they would avoid stepping on twigs and kicking loose debris. They would likely be able to move swifter as well. The hunters would ask “How can they move so fast and yet avoid all obstacles, including my traps?” Especially on a quiet day when there was no wind to make things rustle. “They must have a sixth sense about the terrain around them.” (in this case a 5th sense). Defining this sense would take some time. Perhaps even some plants (like the sunflower) might be classified as possessing this. Real breakthroughs in its understanding would probably come once some small sighted scavenger begins to establish a symbiotic relationship with the sightless humanoids, or vice versa. This would be similar to a dog/human relationship or a human/horse or human/cow relationship. Once a sighted animal becomes domesticated it is only a matter of time. [Answer] Well there are a couple issues to deal with this. First, any animal that has any chance of success, needs to be able to sense its surroundings. Most animals on Earth use sight as their primary sense of their outside world. There are some that other senses replace this. Bats are much more dependent on their hearing, ie echolocation. Your humans would likely have EXCELLENT hearing to the point that they don't need sight. Many blind today are actually learning [echolocation](https://en.wikipedia.org/wiki/Human_echolocation) on their own (or are being taught). So in a wooded area, these humans might actually be aware of MANY more animals than a similarly sighted human. They would hear the mice rustling through the detritus. Now we can imagine echolocation fairly easily because it is an extension of one of the senses we already have. Now it might be much more difficult to "envision" a sense we don't have anything similar too. I'm pretty sure it took scientists to theorize the sense of magnetism. Lots of study and questions. To even guess at 'vision' you would need to have some idea of electromagnetic radiation at some level. Understanding heat might give some clue. But your talking renaissance and some theories at that time still had maggots spontaneously growing out of dead meat. The first 'theories' might be that these animals have very good hearing or smell (or some combination) that allows them to 'spot' things that they shouldn't. I would guess that these explanations would last for a long time. Since most animals DO have better senses than us. Now do these humans have eyes? just useless ones? that might put them off a good theory even longer. If they don't then they might begin wondering what those organs are. Then next step might be noticing that the 'sun' or a large far away fire seems to travel across the sky fairly regularly. Noticing closer heat sources and that their own bodies give off heat might bring about a theory that the eyes can sense these 'heat' rays emanating from the body from a great distance. Without a sighted human to help this along that is probably about as close as a renaissance person will get to theorizing and understanding sight. There will be a bit of misunderstanding once the two peoples meet, especially as we tend to use our vision in our communications to describe things. Human hearing is actually a very decent input tool for people, the problem is most of us have not trained ourselves to utilize it very well. Blind people are forced to pay much more attention to this sense, as well as the sense of touch. Now you have a group of people that have been blind for generations? Their hearing will have improved to make our blind seem deaf as well. And will they will be handicapped in one sense we would be similarly handicapped to them in another. There are [blind people](https://www.youtube.com/watch?v=Z_E3zxx2l9g) who have taught themselves to ride bikes down the road. [Answer] Assuming these humans have all human senses except sight, I'd think the only sense that could in any way detect light would be the sense of touch. There are a lot of cases where light and heat go hand-in-hand; for instance, you can tell if you're under a heating lamp even if you're blind. If someone were to place a barrier between you and the lamp, both its light and its heat would no longer reach you, the latter of which you could detect. While I don't think this would initially be understood as light in the way we understand it, there are definitely applications for this correlation. For instance, imagine a series of mirrors used for long-distance communication: put one hand on the accepting mirror, and another on a control mirror, and if the first one is hotter than the second, light is being transmitted to it. Since you've reached Renaissance era, you probably already have fire available (for warmth and food preparation), and you probably have the necessary shiny metals to make mirrors. From here, imagine a story about aliens on a dark planet that only emit radio waves. It's a wave used for communication that we can't see, but maybe with enough technology or some luck we can at least realize what's happening, and how to use it to our advantage. Going back to light, think about the sun; maybe your humans realize the animals only show up during the hot parts of the day, and someone makes the connection that they're using the sun's heat for navigation. So maybe they start using their super-powerful mirrors to 'communicate' with the animals, and end up burning/blinding them so badly that they can be captured. [Answer] I have serious reserves about a species of human intellect level evolving from the start without sight. Even if they *somehow* achieved this apparently impossible feat, farming is far, far **far** fetched idea. Having said that, even a blind species would be aware of other creatures. That would be through their noises. And occasionally one of them would stumble across a dead hog laying in the fields. Some of them, stumbling across a live grizzly bear or leopard would find the existence of other creatures the hard way. --- Anyhow. It comes to be known that the true perception of a new sensory organ and its working ***cannot*** be understood or proven by mere logic and rationality. We humans know bats have the ability of echolocation. We also know that they use very high frequency sound for that purpose. But how does it *feel* to sketch your environment accurately merely with echoes of your own cry? What is the real *sensation* of that? Nobody knows that. So no. Such a species (which has *extremely extremely* thin chances of coming into being) can never figure out that there is such a thing as *sight*. Reading a short story titled [The Country Of The Blind](https://en.wikipedia.org/wiki/The_Country_of_the_Blind) (author H. G. Wells) is highly recommended. --- **EDIT TO ADD:** Yes it is logically possible to determine that some other creatures have a sense that we do not possess. We see its examples in the form of birds which travel hundreds of miles in their annual migrations and some humming birds are known to find the exact patch of vegetation every year. They must be using some sense for this, we are sure of that (by experience), but we cannot determine exactly *which* sense it is. Similarly, using logic, we can determine that bats use some sort of locating method to map their environment. But with logic alone, we cannot determine which sense it is. For a group of blind people, the biggest hindrance to scientific exploration is ... well ... their lack of sight. We are so predominantly dependent on eyesight that I am unable to figure out how they would track animal movement and figure out their reactions in the absence of sight. It is known that naturally blind people have extremely keen hearing and they can accurately determine distances with hearing. But still, there is a long way to go from saying "Hey! This dog is running away from me once I picked up my lance" to deriving the conclusion "Dogs must be able to map their environment in some different manner than us, because they dodge all the obstacles we place in their way, so elegantly. We could never have done that." I think the evolution of those people would take an entirely different set of sensory organs, which would lead to a different type of logical reasoning than us. They *might* be able to figure out that the other animals use some sort of sensory apparatus which they (people) do not possess, but how they can determine that, is almost impossible for us (visual humans) to determine. Even if they are able to domesticate (they really can do that, if they advance enough to be a farming people) some animals, they would only find it queer that those animals can sense the presence of other objects in their environment far quicker and in far more detail (probably, I'm not sure how much accurate and detailed the surroundings map of blind people would be) than the people. Even if they feel their eyes with their hands, they would hardly have the justification to say "Here! Now this is the organ that creates all the difference!" Unless, some sadist, mad-scientist ... [Answer] I think they might discover it sooner than you think. In fact, I think your humans may construct something sight-like, simply by nature. Let's assume we define sight to be the ability to detect EM radiation (in the usual range). Our humanoids simply don't have that ability. However, that does not mean they cannot comprehend the ability of others. I think their first signs of sight would come from plants. Any farmer sufficiently in tune with their plants would quickly discover that the plants try to grow towards the sun. They may initially associate that with reaching towards warmth, but it would take a relatively short period of time for them to determine that warmth is not sufficient for plant growth. They would be able to tell there is *something* that helps plants grow which moves in a way they cannot sense directly, but indirectly they can infer that something must be there. Once we have the concept of others that have some ability to detect light, it can grow into more complex concepts. They may begin using things that can detect light to do things for us (just like we use dogs for their keen sense of smell). Once you are aware that sight can exist, realizing that there is a sighted species is a lot easier. [Answer] It might go something like this: people begin exploring this new region and notice that they never get very close to the animals that live there. They seem to sense them even when they are walking very stealthily (as they would surely know how to do). They may suspect that these animals have much better hearing than humans do, so they'd probably try to stand completely still to avoid making any noise. They may notice that this works a lot better in forested areas than in plains, but no one can figure out why. Some of them may get tired standing in the plains all day waiting for animals, so they often lie down in the tall grass while they wait. It's soon noticed that the animals get much closer before they're able to detect the humans and run away. These and similar observations are recorded and brought to their best natural philosophers with the hope that they will be able to make some sense of them. These people, although sightless, would certainly have a good understanding of 3d space, since they must navigate it somehow to find food, materials for tools and shelter, to avoid predators, etc. Most of the people already realize that the way these animals are detecting their presence depends heavily on the geometry of the surrounding environment and their position in the environment relative to other objects. It wouldn't be too big of a leap to notice that when there are objects (grass, trees, boulders, etc.) between the (silent) humans and the sighted animals, they usually cannot be detected by whatever sense the animals are using. This wouldn't seem too far-fetched because the presence of obstacles affects their own ability to hear sounds emitted from the other side of those obstacles (usually making them more difficult to hear). They notice that the sense used by these animals is affected to a much greater degree by the presence of objects between them and the animal than their own sense of hearing is affected by the same obstacles. From there it's a pretty straightforward idea to surround oneself with objects while waiting for the animals. When this technique is used, the animals get closer than ever before and the humans often go completely unnoticed. At this point, even though they don't understand the exact nature of sight, they now would have the ability to counteract the animals' sense of vision. Now, I'm not sure what you mean when you say that traps are not allowed. I don't know why the fact that these people don't trap animals for food would mean that they couldn't come up with the idea to set a trap. I'm also not sure what you would consider a trap. Is it just that automated traps aren't allowed or can they lie in wait and pull a rope to trigger the trap at the right moment? If neither is allowed, how else would they capture an animal? A lasso? Running up and grabbing the animal? Both of these would be extremely difficult (and most likely quite dangerous) for blind people. If a manually triggered trap is allowed, then all they would have to do is get some bait, hide themselves and wait for an animal to come, use the sounds made by the animal to determine it's position and trigger the trap at the right moment. It may take a few tries, but they would get it right eventually. If this kind of trap isn't allowed, I guess do the same thing except instead of triggering a trap, just get a bunch of people to run toward the animal from different directions and hope it's not a bear or a deer. Although this is more of a stone-age level of sophistication than a Renaissance one. Edit: I wrote and posted this before I saw the extensive changes you made to the question, including the removal of the restriction on traps. Does that mean they're allowed now? If so, I'll change that part of my answer. [Answer] Exactly the same way that non-psychic humanoids would discover the abilities of psychic humanoids which avoid the non-psychic humanoids... Never! The non-sighted humanoids might be able to discover the concept of sight if they were to interact with sighted humans. In which case the non-sighted humanoids might notice the exceptional abilities of the sighted humanoids. Eventually, they might start noticing patterns. For example, the abilities of the sighted humanoids are much better in open fields and during certain hours of the daily cycle (I assume that the non-sighted humanoids have the concept of day and night albeit not as clearly defined as the sighted humanoids ). They might be stumped as to why sometimes the abilities of the sighted humanoids are relatively sharp during the night (as they are less likely to understand the monthly moon cycles). Even then, their concept of sight would be rather nebulous. In the extreme case that a sighted humanoid came forward and revealed possessing the ability to see, that humanoid might be found guilty of deception or trickery instead. The best chance of the non-sighted humanoids to understand sight would be to hold constructive discussion with sighted humanoids on the topic of sight. ]
[Question] [ In some science fiction and fantasy settings (mostly fantasy) there are sometimes things like rock giants or rock golems. Basically, what I'm getting at is rocks forms with, sentience in some cases. So I was wondering if it is at all feasible for beings like this to evolve into human like creatures. They do not need to be made entirely of rock, I suppose, but how far from rock would they have to be? How would their bodies be able to function if it was possible? [Answer] **Go for a silicon based life-form as most rocks have a high quantity of silicon in them.** While not strictly a Rock-Being as we are accustomed to thinking about them in fantasy stories, a silicon based organism would share many characteristics with the Rock giants you want. They will need to eat stone or stone like substances for food. As long as the evolutionary process is right, there's no reason they couldn't be as intelligent as humans. [Answer] perhaps something like an assassin bug or decorator crab: instead of being literally made of rock, it sticks rocks to its outer hide as an easy means of self-defense. this would be pretty easy to evolve, as you basically just need sticky skin. this would let you have golems of multiple different shapes, sizes, and appearances. another fun idea: as the organism grows older, it could accumulate more and more layers of rock, eventually becoming so heavy than it transforms into a sessile adult form, more like a barnacle, and possibly changing into a female as well. at this point, its main source of nutrients would be any animals that wander close to whatever "mouth" it has, and it could reproduce by attracting one or more male mates and than raising the young inside itself. the crab comparison actually makes me thing of a rl example of what im thinking of: there is a species of crustacean that begins life as a standard, shrimp-like larva but on reaching adulthood enters the body of a fish and morphs into a network of parasitic fibers. the rock monster could work similarly: the young are hard-shelled insectoid creatures with stone shells, the second stage of life sees them start growing connective fibers and adding more and more rocks to their body, and finally turning into a large pile of rock-covered flesh with the original body in the center. [Answer] If you have a body made *completely* of rock, the best you can get is a statue. As far as I know, they are dead pieces of rock. If you have a body with its *skin* made of rock, you are asking for the same thing. Rocks have zero elasticity as far as I know. So if/when your character moves a muscle, its body will crack at some point and it will bleed to death. If you have a body made of skin like normal creatures but bones made of rock, this is not possible biologically. Rock is all silicon. Earthly organisms (all of those we know about) do not digest silicon or have systems for converting silicon compounds into rock. The closest there is, are calcium and phosphorous metabolisms, converting them into bone and shells (of sea creatures). Rock tends to be extremely *weak* when as thin as a bone. Also it is very much heavy and frankly it will hurt your hip muscles like hell when you sit down. Ouch! So no, practically speaking, you cannot have any creature made of considerable quantities of rock inside its body or outside. [Answer] Maybe you could want a silicon-based being.It wouldn't be very Earth-like (silicon cannot do all the things carbon does)and it would be very different, but, if we suppose intelligence evolves when it's needed to resolve adaptation problems, I think it could be sentience. Silicon can work where a planet is too hot to allow carbon to work (look at [this](https://www.cfa.harvard.edu/~ejchaisson/cosmic_evolution/docs/fr_1/fr_1_future5.html)). I hope it helps. [Answer] No. A self-repairing self-building object will need an internal distribution network and units that are chock full of machinery for building and maintaining the unit, with structural support being a trade-off with all the stuff needed to make it work. Most of the stuff will be nanomachines intended to fill a role, *not* just be a rock. In short, cells are full of stuff needed to make it live. Bones are crawling with cells to dissolve and lay down mineral, and is a composite with protein as well as mineral, and shot through with blood. Shells and tests can be secreeted with various mechanisms, but require living tissue to generate it. An armored creature or big shell is not what you mean, right? You are asking of rock = living tissue. It's not. [Answer] Since you're just "tossing the idea around", what about a being with a special affinity with rock? It's born as a biological being, possibly slug-like but long and maybe with tentacles, and capable of secreting rock-disolving acid (or has some other rock-shaping tools). As it "grows" it's actually collecting the surrounding rocks and fusing them with itself shaping it to "build" its body, until it has collected enough rocks to form the armour or bones or whatever else you need to consider it a rock-person, while original organic bits form the muscles. At this point it's considered to be at full maturity. The creatures could only be reared in rocky areas, of course. [Answer] You could take some inspiration from [Diatoms](https://en.wikipedia.org/wiki/Diatom), they're coral-like free-floating algae that use [Silica](https://en.wikipedia.org/wiki/Silicon_dioxide) instead of [Calcite](https://en.wikipedia.org/wiki/Calcite) to build an exoskeletal structure. Basically you'd have an inert "rocky" silicate layer wrapped around a life-form that is carbon-based and can be pretty much human in terms of biochemistry and anatomical structure. With the right structural considerations, under limb freedom and skeletal anchoring, you could easily have ten or twenty centimetres or even more of rocky material over your otherwise human analogous creature. [Answer] Let's make this one out of carbon. To keep things interesting, let's make that *pure* carbon, with no other elements, in a roughly room temperature environment. Let's put it on the Moon to avoid burdening it with too many extraneous gases. Our ooh la la will come from [this news story](https://phys.org/news/2021-10-photon-phonon-breakthrough.html) in which it becomes possible to herd phonons (sound vibrations) at an interface of silicon and boron nitride. These are both conceptually similar to diamond, and I'll assume without proof that the technology can be extended by a lucky evolutionary process. The article, which promises to move heat in arbitary directions within a larger structure, is some proprietary horror so let's look at an [ArXiV preprint](https://arxiv.org/pdf/2105.08153.pdf) that seemed to predict it. They start off saying "Nonlinear effects open up a wealth of possibilities in quantum optics, harmonic generation, all-optical light modulation and switching, and nonlinear microscopy and sensing." Now that's almost a textbook list of features of life (if you squint at it hard) so let's describe our organism. We should consider the organism probably uses all the [allotropes of carbon](https://en.wikipedia.org/wiki/Allotropes_of_carbon) and would construct other structures at an atomic level only approximately describable according to any of them. Power source is solar: energy is absorbed by deep black layers of graphene. These convert the light to phonon-polaritons in the short term. Reflecting early evolution, these photosynthetic organs serve directly as muscles, using the captured phonon-polaritons to slide or rotate graphene elements such as nanotubes, which are crafted in appropriate geometry to respond to this energy source. As with any thermodynamic system, the motion would be entirely reversible and random if the entropy were not dissipated: heat from the phonon-polaritons is radiated to space at some point on the outer surface. Note that these areas can be controlled and shifted at will using now-current technology. Power storage relies on graphene-lubricated diamond latches. A "muscle" contracts, momentarily stressing the bulk diamond of the organism, and then it is latched into that position to store the energy. This mechanism also permits engineering for leverage well in excess of what the muscles can deliver. Feeding means intake of more carbon, which is done by smelting carbonaceous chondrite using (ancestrally) sunlight focused through the diamond portions of the organism, or by focusing phonon-polaritons very precisely at a point. Reproduction works a bit like feeding: phonon-polaritons from throughout the diamond flesh of the organism are focused to a narrow point, but tuned specifically to catalyze diamond-to-graphite transition. The result is that a new graphene photocell/muscle structure is constructed bisecting the organism. The genetic code would be distributed throughout the organism at sites where carbon allotrope structures vary in a way that stores information. It might be seen as a prolific set of adaptions from the muscle structures that move in response to phonon-polariton energy. I'll admit ... my reality check needs a reality check. :) [Answer] You could have a creature that goes into a rock like state at various times in it's life e.g. as a form of hibernation (there are insects and fish that can survive being frozen) or as a very patient pounce attack. The creature itself is *fairly* humanoid normally but has this transformative process. If the process is very fast and controllable, in its now evolved intelligent form, it could lead it to something similar to the behaviour of the [Weeping Angels](https://en.wikipedia.org/wiki/Weeping_Angel) from Dr Who. ]
[Question] [ I just asked myself what is the role of the mountains on Earth? Well there's a well known role for the climate and weather. But is there a kind of physical or geological role? What would happen if our Earth had no mountains on it? Would we have more earthquakes? I suppose erosion will be much heavier than it is now. I would like to get some kind of scientific answer if possible from a geological point of view! **EDIT:** I posted the Question later also in [earth science SE](https://earthscience.stackexchange.com/questions/5346/what-would-change-if-our-earth-lacks-mountains) after reading the comment of user6760 [Answer] ## No Plate Tectonics To have a world with no mountains occur naturally, there must be no plate tectonics. To have no plate tectonics, there must either be no moon, or the moon must be tidally locked to prevent its gravitic influence causing heat-producing deformation of the world. A consequence of this is that there would be no earthquakes and erosion would *eventually* level land and sea-floor alike until it was eventually all an equal depth beneath the water (aside from small solar tides). There would be no geomagnetic field (that being caused by the same processes as plate tectonics), which would allow higher radiation levels at the surface. ## The Mountains were taken away! If earth's mountains were magically instantly removed, there would be immediate repercussions. All that stone has mass, and the crust beneath which had been pressed into the mantle would rebound, causing worldwide earthquakes. Volcanoes would erupt as their plugs of stone were removed or weakened. All this is not considering the effects on the global weather patterns. In the long term, mountains would reappear as plate tectonics continued to deform the landscape. [Answer] In addition to the answer by Monty, I think it's important to mention that mountain formation has a side-effect of "excavating" minerals from deep down within the earth and bringing them to the surface. When plates collide to form mountains, the bottom layers of Earth's crust rise to the top with the mountains. This allows us to then find various metals and minerals within the mountain ranges. Plate tectonics is effectively a blender for the Earth's crust. Without mountains, mining would have been very different. We would have to dig down several miles before finding any minerals/metals, and to make things worse we'd have no tools for such a job since we've been manufacturing them out of... metals. Any materials we would have available to us on the surface would be too soft to dig the harder materials down below. [Answer] If you want to see what happens without tectonic mountains, you might do well to look at Australia, much of which has been geologically stable for a very long time. Outcomes of that include the majority of the country being very flat and quite samey ( you can drive hundreds of miles without more than the mildest inclines ) and in places like the Blue Mountains the mountain range is actually created as the result of a canyon system from an ancient river. If you wanted to avoid this type of terrain you would either need to have no eroding agents ( which makes a challenging environment to design ) or to have very hard rocks that don't erode, which is a challenging environment to populate as that is where most soil comes from. One good bet for this type of environment might be a very old planet, tectonically dead and then eroded down about as far as it can be. Of course, the natural consequence of this on an earth-like planet would be that it would be covered by a fairly uniform depth of water, so I guess any life you have there would probably be aquatic. That said there are some arguments that [tectonics were a necessity for life as we know it](http://www.dailygalaxy.com/my_weblog/2014/05/without-plate-tectonics-life-on-earth-might-never-have-gained-a-foothold-harvard-smithsonian-center-.html), so evolution without that factor might travel along a very different path. [Answer] Weathering of rocks is how CO‚ÇÇ is removed over time. So without erosion the carbon cycle fails and the Earth ends up like Venus. [Answer] Two things that are really important: 1. erosion of mountains soaks up a lot of Carbon from the atmosphere, so much so that even the plants would choke on excess CO2 if they didn't. 2. mineral cycles, without continuous turnover certain elements, Phosphorus for one, get washed to the sea and that's where they stay, no mountains would mean that life as we know it would go under for lack of Phosphorus, Sulfur and possibly even Iron. As a note erosion of mountain-less terrain is relatively slow due to the lack of [Orographic Rainfall](https://en.wikipedia.org/wiki/Orographic_lift). ]
[Question] [ In my world I have a couple species of sentient animals, mainly cats, who among other things are capable of communication with human beings. While I am perfectly happy to resort to explanations involving magic to justify their increased intelligence, and them using it an a human-like way - these species already have some sort of relationship with magic even without involving their speech ability - I would like to incorporate "real life" distinctive aspects of these animals' anatomy in the way they sound when speaking a human language, or even in their ability to understand it. **What would the phonetic features of a human language spoken by a sentient cat be?** Also, **how would their ability to process human languages spoken by humans change?** *Edit: It has been pointed out to me that the question was very broad. I am also interested in the same question applied to birds of prey and possibly other animal species as well, but I edited to focus on the species that is most relevant to me.* [Answer] There are a lot of interesting aspects of human and feline vocalizations to consider here, and while I'll admit I'm not expert, I'm going to attempt to tackle some of them here. First of all, from [this video about humorous cat noises](https://www.youtube.com/watch?v=ze4IjB8RxsQ), you can see that there are many noises cats can make. A lot of them sound completely stupid, but I imagine they'll be a lot less laughter-inducing coming out of larger feline species with longer vocal cords. The main problem you run into is that many human languages are made up of dozens of [phonemes](https://en.wikipedia.org/wiki/Phoneme), or individual sounds; while cats can produce many of them, they most certainly struggle with others. Something that I learned while researching this (from [this article](http://moderncat.com/articles/12-sounds-cats-make-and-what-they-mean/68602) and others) is that `the meow of an adult cat is almost exclusively used to communicate with humans, and not other cats`. It may be a variant of the sounds kittens make to call their mothers; cats use meows for a similar purpose, to call to their owners. With this fact in mind, it is conceivable that cats may be able to produce other noises that they have not yet learned to use. Right now, a simple meow does the trick, but with practice and the desire to convey more complex ideas, cats can probably manage to stretch their abilities to cover more phonemes. Another consideration you should make is that human languages aren't built for cats; thus, there will be a lot of words that are hard for cats to pronounce. Humans get that with their own languages; for instance, I occasionally amuse myself trying to pronounce French words correctly, but I know I would be nearly unintelligible to a native French speaker. But while issues learning a language can usually be solved with practice or by learning when you're young, there will always be some words cats just can't speak. For these words, and probably most of the language, they'll have to speak more slowly, and really be sure to enunciate as clearly as possible. If you want to know how a specific human language is going to sound being spoken by a cat, first find a list of that language's phonemes(they're not just the letters, for instance here is a list of [English phonemes](http://www.auburn.edu/~murraba/spellings.html)). These are your building blocks, as every word in the language will be made up of them. Next, try and match each phoneme to a cat noise. If some noises cover multiple phonemes, that's fine; it may make the cat harder to understand, but it'll probably be unavoidable. And finally, test out some words, and see what the cat has to do to speak them. Some sounds are going to be hard to put together; for instance, it may be difficult for a cat to switch from a purr to a meow. Transitions like that are going to slow your cat's speech down, but in other places the words may flow just as easily as for a human. In the end, it's going to sound strange, kinda funny, and nearly unintelligible. But pets always seem to have a way to get their meanings across; I'm sure sentient ones will be even better at it. [Answer] I would observe cats as research. I think lots of hisses would be incorporated into the language, particularly in anger, cursing, rage, etc... Tone is also a large aspect of language. The Khajiit race in Elder Scrolls series comes to mind as well. The big thing to take into account is BODY LANGUAGE. Body language often communicates more than actual words. If the cat race has the tail this would be a unique aspect. Wagging the tip of it when anger, hair standing up on their spine, dilated pupils, pawing motions, rubbing/nuzzling against one another for affection. The body language piece is key. [Answer] Read up on the IPA standard notation, and the descriptions of the different types of sounds which is how they are produced anatomically. If the voice box is changed without outward visible signs, what about teeth, tounge, lips, and the manner of nasilelization? What sounds can be made depend on the anatomy and the possible motions. Can a cat make a kissy-lips pucker? No? Well, no /w/ and no "closed" vowels like /o/. ]
[Question] [ I am devising a magic system that requires the user to output their energy (say, metabolismic calories) as a trigger, thus letting the sea of mana do the rest. Still, the sea of mana would multiply the energy input (user's output) to a usable level. Regarding the scale, how would I measure the ratio of a user's output to the total resultant output (user's output plus mana's augmentation) based on the value that I named "Negative Mana Resistance"? It is easier to think of, but when it comes to the math, it shows its difficulty. The idea is that the more a user performs mana bending, the more the sea of mana (which permeates everywhere on the planet's surface, and probably the entire planet) understands their intention, and so the enhancement being done by the sea of mana increases (both in quantity and quality), hence the name "Negative Mana Resistance". As the mana resistance of an individual goes lower, it reaches a negative value, at which point the amount of energy the user spends would be enhanced rather than partially transfered to the mana manifestation (some people, most of them actually, have positive resistance; that is, the energy they output would be partially transferred to the process of mana bending; thus, the force they expend to perform mana bending would be more than the actual mana manifestation triggered, thus rendering their ability generally similar to ordinary human). How would it be translated into an equation? I assume that this "understanding by the sea of mana" must be quantized somehow, but how would it work? Perhaps with accumulated exposure period? Note: The tag for [science-based](/questions/tagged/science-based "show questions tagged 'science-based'") refers to the question's requirement to propose a quantitative system of magic that could be determined should the effect of the magic be studied scientifically. Note 2: To summarize, I need a basic framework of principles that could account for: * Exposure time * Accuracy * Baseline resistance * Tendency to reduce resistance value based on exposure time and its relationship with accuracy * Resultant resistance Note 3: For answer(s) that satisfy the question (or most of it), I'll give a full credit in-universe; it would be nice to include a way to refer to the system you've invented or conceived in your answer, like: Master X, in his/her book "Whatever the book named", year XXXX; or: AnswererName's Law of Reality-Bending NB: Please tell me if this question is off topic or if it lacks something, or anything I could do to improve it or to make it on-topic, as personally I don't know where to ask for this, as I thought it would be ridiculous to ask it on Mathematics SE. Note 4: Just to clear up things, but in the question, it is suggested that the one having negative mana resistance will be superior in magic, as they basically could outputs more with littlest input from them, and 0 resistance actually means input that a user spent would be equal to the resultant mana manifestation. [Answer] This answer is based on the world described in my other answer. This one is focused on the portion of the interaction between the sea of mana and the individuals that science will quantify and model quickly. It leaves open the idea that there are other ways to interact with the sea, and only concerns itself with what will get discovered quickly by science. Nowhere in the description of the equations you are looking for do we talk about things like "difficulty of spells" and whatnot. All of the variables focus on the state of the individual. This is actually a very natural result of a scientific approach. Science will choose to isolate the "physical world" from the individual caster because science likes to divide problems up that way. It will assume the physical world's effects are independent from the caster's effects, so you can come up with any model you please for how people make fireballs or do telekenetics or what not, and then layer on this model for handling the individual "negative mana resistance." Since this is all about the individual, it is natural to look to psychology for inspiration for the equations. I would easily consider spellcasting a "skill," and as it turns out, there is a *very* commonly occurring curve in psychology/education/etc. called the [logistic function](http://en.wikipedia.org/wiki/Logistic_function): $f(x)=\frac{L}{1+e^{-k(x-x\_0)}}$ One method of measuring "skill" involves assuming that each individual has some "skill value" which scores them on a number line. 0.0 would be the least skilled score someone can achieve, 1.0 is the best, with 0.5 being an average skill. This approach has been studied in great detail in the field of education, and we find that, if you try to order individuals from 0.0 to 1.0 evenly, and then look at the quality of the results of applying a skill, people have a curious tendency to fit on a logicist curve. It just seems to happen. The layman's version is this: * At low skill levels, you really don't understand the material. However, there is some chance of getting the answer right with random luck (ex: on a multiple choice test with A, B, C, D, and E, you have 20% random chance of getting an answer right, even if you don't know a thing about the topic). * At some point, you reach a point where the material starts to fit into your mental model of how the world works. There is a rapid rise in effectiveness as you progress along this curve. * Eventually you master the topic, at which point additional "skill" doesn't really help, The topic is under your belt. There are, of course, skills where this is not the case. However, from an educational background, science tends not to try to model those cases. They're just not a good fit for a scientific process. Thus we expect science to find examples where this curve "fits." So let's add one more term: $f(x)=\frac{L}{1+e^{-k(x-x\_0)}} + C$. Now we can map these real life patterns into the equation. * $C$ is the "random chance" term. It's how well someone does when they are completely untrained. * $L$ is the "maximum effect of skill." The higher this is, the more difference we see between the unskilled and skilled values. * $x\_0$ is the "inflection point." This is the percentile of the individual who is right in the middle of the process of getting it. It naturally will be a value between 0.0 and 1.0, but it usually is closer to the middle (just to make sure we see a good portion of the whole curve). It is a measure of how hard it is to learn a skill in the sense that a higher value means you have a long period of learning before you finally "get it" and can achieve mastery. * $k$ is the "steepness" of the curve. High values of k lead to situations where there is a sudden "dawning understanding" which gives you mastery in one sudden motion. Low values of k lead to situations where you have to work at it for a long time, steadily improving. Here's the list of things you want to appear in the equation: * Exposure time * Accuracy * Baseline resistance * Tendency to reduce resistance value based on exposure time and its relationship with accuracy * Resultant resistance (this seems to be an output) We have 4 variables and 4 things we want to measure. JOY! * $C$ - related to baseline resistance. There is some baseline ability for casting, and it is represented by $C$. * $L$ - tendency for reduced resistance. As you learn more, you move up in the "skill" ranking, and the effect of that is more pronounced if $L$ is large. * $x\_0$ - Accuracy. The more precise the effect you are looking for, the higher the "skill" where the transition from untrained to trained occurs. * $k$ - Exposure Time. Like many things which you can work at until you get it right, the longer your exposure time, the smoother the curve will be ($k$ goes down as exposure time goes up). Just to avoid this weird signage flip, science would probably refer to "exposure rate," which would be the reciprocal of exposure time. That way, $k$ goes up as exposure rate goes up. One detail: you want to think of things in terms of "negative mana resistance," which is not a typical way of approaching psychology problems. However, if that is the form you want it to be in, it would be trivial to assign $C < 0$ such that an untrained individual spends more trying to channel mana than they get back, but when you cross the x-axis, you start getting more effect from the mana than you spent channeling. Now different types of spells could be harder or easier to manage. Science would bundle them up into categories, and try to define a logistic curve for each. If you chose a Magic: the Gathering style of spellcasting system, each of the 5 colors (white, black, blue, red, green) would have a different logistic curve, and each person would have a skill value assigned for each of the 5 skills. When it comes to more complicated skills, this curve would break down because it would become too difficult for science to objectively define the behaviors it wants to see. Accordingly, science would stick to measuring very brute force approaches (i.e. "a solid wall of red-magic force"). The magic equivalent of martial arts may identify that there's more to the problem than that (i.e. they start to uncover the true interactions between the sea of mana and themselves). Each art may define its own approach to quantifying these effects. I guarantee you that the Chinese martial arts will associate this sort of magic with Chi in no time flat, and begin doing really interesting things with it which science initially will claim are impossible (but having to admit that someone might be doing it anyway). Over time, science may refine their laws. The previous answer I gave is completely consistent with modeling the sea of mana as a 3-d array of non-linear elements a. la. computational fluid dynamics. However, the equations you get out of that will be beyond the scope of most readers (read: researchers pay hundreds of thousands of dollars to get software which has thought through those things for it). The equations from the logistic curve should be enough for science. [Answer] $\dfrac{E}{\Delta t} = \dfrac{1}{(m\_r)^2}m\_t$ $E$ = energy output $m\_r$ = mana resistance, where 0 is the lowest (the equation is undefined at that point because with 0 mana resistance you can do anything): The higher the mana resistance the less the sea of mana helps you. $m\_t$ = the strength of your mana trigger $\Delta t$ = change in time: this is so that releasing energy in a short burst is harder than a releasing energy over a long period of time (think explosion vs burning a log) Therefore, a normal person has a mana resistance of infinity. A mage has a finite mana resistance. [Answer] # My method of choice I apologize if I go through this overly slowly, as I'm trying to work it out for myself as I go along. ### Basic model A person can give an output (an input into the "sea of mana") of energy $I$. The sea then acts as an energy trransfer, and gives an output of energy $O$. Based on what you said, the more energy a user puts in, the more energy comes out. This means that $O$ is proportional to a power of $I$, or, in mathematical notation, $$O \propto I^n$$ where $n$ is the exponent. It doesn't have to be an integer, though. However, it seems that $O>I$, so $n>1$. You can choose this $n$ and have it work for everyone in the population. Now we can build in resistance. Let's add in a coefficient, $\alpha$, making the law $$O \propto I^{\alpha n}$$ Less resistance means greater values of $\alpha$, and vice versa. Now, for $O>I$, $\alpha n>1$. I said earlier that $\alpha n{\color{red}>}1$. This is because $I$ is enhanced by the "sea of mana". However, you said that for *negative* resistance, the opposite is true: $I<O$. For this to be the case, $\alpha n {\color{red}<}1$. Here's some behavior of the equation: $$\text{As }\lim\_{\alpha n \to 0}, \frac{O}{I} \to \infty$$ $$\text{As }\lim\_{\alpha n \to \infty}, \frac{O}{I} \to 0$$ Putting in a constant, $c$, to satisfy the $\propto$, we have $$O=cI^{\alpha n} \tag{1}$$ ### Baseline resistance We have to change our exponential term to account for this, so we add a constant, $\beta$, making the equation $$O=cI^{\alpha n + \beta} \tag{2}$$ **Slight detour** This gives us another variation. Say we keep $\beta$ as our baseline. What if we say $\alpha n=-\gamma$, and that if $| \gamma |>\beta$, the resistance is negative? That works. It might be simpler. ### Summary I haven't actually used a negative sign anywhere, except in the detour. Notice, though, that you don't have to. Exponents make things much more interesting, eh? # Other ideas * Have resistance be proportional to a constant, $\delta$, squared ($\text{Resistance} \propto \delta^2$), but for those with negative resistance, make this $i \delta$ (as $i^2=-1$). * Have resistance be expressed as $$R=\text{baseline}+\text{specific term}$$ and have the specific term be negative for those with negative resistance. * Have resistance be proportional to $\epsilon^{\upsilon}$, where $\epsilon$, $\upsilon$, or both can vary by user. If only $\epsilon$ varies, then positive/negative resistance depends on whether or not $\epsilon>1$. If only $\upsilon$ varies, then positive negative resistance depends on whether or not $\upsilon>0$. [Answer] > > Though my friend's original conception would be that the energy is > recycled by souls of the dead (I object it and say that it draws > energy from ambient energy of the surrounding, say the sun, or > geothermal, or vacuum energy) - Hekdrik Lie > > > What if you could have both? What if it could be recycled by the souls of the dead, and simultaneously be drawing energy from the surroundings? It turns out combining the two is not as unreasonable as they may first appear, but we need to change the focus slightly. Your question focused on energy, but I would recommend focusing on information instead. The two are closely related, but the bridges you may want to cross are easier crossed with information theory rather than energy balances. Consider which is more powerful, access to 4MJ of energy (the average energy in a daily intake of food), or the knowledge of where to find a bulldozer with a full tank of gas. Clearly a being with such knowledge could do spectacular feats, especially if nobody else could see the bulldozer for one reason or another. [Maxwell's Daemon](http://en.wikipedia.org/wiki/Maxwell%27s_demon) is one way of looking at the connection between information and energy, and it is an important one to the world of physics. Basically, the argument is that, once a particle reaches a uniform distribution in a container with two rooms, there is no way to shut a door between them to trap the particle in one chosen room more than 50% of the time. This is considered an absolute rule by current physics. QM bends it, but even QM doesn't break this rule. But there's a key assumption to the Daemon: the assumption that the particle is randomly distributed at the start of the experiment. What if it wasn't? What if there was structure to the way the particle bounces, which we had simply forgotten. When we go measure it, we see it as a random distribution. But what if the Daemon knew better? What if the Daemon could predict the position of the particle at some time and simply wait for it to get there. In theory the Daemon could create any steam engine it pleased with this approach. It just may take a lot of dedication. With oracle like knowledge (knowledge not explainable by physics), it could even generate infinite energy. But we're not looking at that extreme, we're looking for something physically realizable. [Landuaer's principle](http://en.wikipedia.org/wiki/Landauer%27s_principle) gives us some physically realizable ways to do this. It states that the minimum amount of energy needed to erase one bit of information is kT ln(2) (technicality: The Daemon is erasing one bit of entropy in the universe. This can also be thought of in layman's terms as adding one bit of order to the universe). The hotter you get, the harder it is to erase a bit. In theory, computation done at absolute zero could calculate anything for free, but in reality, there's no degrees of freedom at absolute zero to do calculation with, so we have to just settle for really-really-cold. *A note here: this limit is really really low. At room temperature, it takes a mere 2.85pJ of energy to erase 1 bit of entropy. Our modern computers are a million times less efficient* So what if we could do our calculations in the ultra-cold of space, we could work at [28K](http://en.wikipedia.org/wiki/Cosmic_microwave_background) instead of 280K (which is room temperature). That gives us an even lower bound of 0.285pJ/bit. That's not much. Now before we return from Wikipedia and start really tackling the problem, its worth noting that reversible processes can exceed this limit, because reversible processes are theoretically not bound by thermodynamics the same way irreversible processes are. This is the basis for Quantum Computing, but there is, as always a limit. One has to get the data out of the quantum computer, which involves erasing bits. However, you only have to erase enough bits to get the answer out, which is often many fewer bits than you would have needed to solve the problem classically. And this is where your computronium comes into play: it can do things like this. It can run reversible calculations to emit only the minimum output. In fact, it can emit output undetectably to science, simply by concentrating its classical outputs in locations science is not looking. As long as it outwits the science, it can stay hidden (and note, the shift to terminology describing intelligence is no mistake). The question is how does it get this information, to avoid being detected. It literally needs to find bits of entropy that are "forgotten," i.e. unusable by science, capture those bits, and ensure science never sees them again. It can't do this with things like solar energy directly - it doesn't have much better of a chance at predicting information in solar photons than science does. However, there is a corner where science doesn't look: death. Science really has no idea what happens at death. We've got some ideas, but generally speaking, lots of information in the body decays faster than we can even consider looking at it. Thus it is not unreasonable to assume that there is some information in or near the soul that escapes science's net in the form of information that is too ephemeral to really pin down with statistics. This information could be captured by the computronium without wasting too much energy. This information could be used to better predict when and where the scientists are looking, keeping the entity hidden. This entity could then use this information at its maximum effect. For example, if a fireball was desired, it may be able to summon up an information net across the entire world to create a fireball in one location counterbalanced by a millionth of a degree decrease in temperature around the world. It could then take advantage of the fact that it's the only one who knows that millionth of a degree shift occurred to harness the suns energy across the globe to pay the energy price for the fireball. It simply has to know enough about how the world world works to do that process "reversibly." And that is the limit of this creature that you need to prevent limitless power. It can only exert its infinite will on small things. The larger a task, the more likely it is that the imperfection in how it does reversible computation will crystallize unexpectedly, like whitecaps on an otherwise energy-conserving sea. The entity has to be careful: what are whitecaps to it could be catastrophically powerful waves of force for the denizens of earth. As for your negative mana resistance? Now its easy because, instead of being a very strict physical law you look for, it's more of a social law. The entity will exert its power where it is most efficient. If you are willing to look the other way, it can do great things, simply because it can get away with doing them affordable. In fact, if you develop enough of a report with the entity, sharing a common language, it may find it in its interests to actually give you energy. It'd be a win-win. You get energy, and it gets a voice which will effectively evangelize the best ways to not look at it, so it can continue to grow. There are also really interesting religious subtexts here as well. The most obvious is the Taoists, who seek to become Immortal by becoming one with the chaos of the cosmos. Perhaps the Taoists were one such group which attained favor with the entity, and were given protection in return for cultivating a life which brought more information to the entity. At this point, the physics the scientist sees can be anything you please. The entity would present itself in a form the scientist would understand. The scientist would understand laws of nature, so it would present as having rules. However, as science tries to tap this "limitless" power, the entity would have to shift to avoid loopholes, slowly teaching the scientists how to live in harmony with it. ]
[Question] [ I just watched Rango, and I got curious of the realistic implications. Let's set the stage. * Desert environment. * Realistic 21st century American tech, unlike the movie. * Some foreign country based on a trade economy. * They're starting to accept foreign trade, but considering that they lack a currency, they settle on using something everyone wants: clean water. * For transaction to be legal, it must be in any size bottle with volume marked, purified (Minerals allowed, as long as they're what you find in common tap water.) and certified sanitary. * Like in Rango, there are banks. They have the expected, a purification center, a test for cleanliness, and a holding tank with UV sanitation system added. Purification is provided for a fee, and required to deposit. * Let's assume they've got easy access to high-quality retail water cleaning machines. I've seen those at camping stores, and they'd sell like hotcakes here because... * ...Everyone has to find their own water and clean it. There's a river that one could build a home near, or pipe water from, but tax is higher and there are heavy regulations. Tax is really low away from the river. * City water is a thing, but you have to pay for it with something else. Remember that it's a trade economy, the logic is that they sell stuff to the city and get paid in water. So, what would this imply? Anything really weird? Could it even hold up? [Answer] Sure, anything is valuable IF EVERYONE AGREES IT IS VALUABLE. The reason paper money is valuable is because the nation backs it and says that it is worth a certain value; and said nation is able to back up that claim with its own national profits from goods and services (GDP) and its reserve (typically in gold). Hence, if water is rare enough to become precious, it is possible. However; currency is initially invented using precious metals not only because they are hard to find; but also because they are pretty when worked, highly durable (against chemical reactions, not impacts), and workable into something that you can carry around. The issue with water as a currency hence lies its portability and durability more than anything. How many 2L bottles can you realistically carry with you? Its generally assumed by travellers / backpackers that you can carry *at most* 2/3 of your body weight in a camping backpack. Problem is, whilst fresh water weighs a handy 1kg (2.2 lb) per litre; the more contiminated it gets, the heavier it also gets; seawater is considerably heavier due to the salt. And then, you can lose your profits really easily. Half of it could evaporate, spilling your drink costs you a weeks wages, and you could totally screw up the economy by tapping or contaminating water supplies. Furthermore, water is used in everything. We drink it, we use to make food, we use to clean, to create alot of things, to carry away waste etc. It would be a nightmare to keep a pocket book of your exact ingoings and outgoings, even if you meter the precise incoming and outgoing water from every home. Due to these idiosyncracities, water is a poor currency, and its going to be abandoned as such in any sufficiently large society. Frontier villages might directly use it, and it will remain an important barter good, but as the actual main thing to trade its rather unlikely. [Answer] Water was currency in the novel "Dune", for many of the same reasons you mentioned in your question, but the value of such currencies is always limited by the special circumstances which limit or eliminate the more "formal" mediums of exchange, so water may be "currency" for a very limited time and over a very limited geographical range. Even in Dune; water was only valuable on the planet Arakis itself (paying someone in water on a different planet would get you laughed at), while "Spice" ended up being the universal currency/trade good because of its absolutely unique properties and limited availability. Even on Dune, while "Spice" was the formal store of value, no one in their right mind would walk around with a bag of "Spice" to buy groceries; the value was translated into some form of currency for actual day to day transactions. When money was backed by gold or silver bullion, few people walked around with a bag of gold, but carried paper currency with an agreed on redemption value that was theoretically reflected in a nation's bullion reserves. This was one of the weaknesses of monies backed by precious metal; if the reserves changed (i.e. a gold strike, or selling the gold to fund a major war), then the value of the currency was also affected (there might not be enough gold to redeem the amount of paper currency in circulation). Of course modern "fiat" currency has a few issues of its own... [Answer] One implication of using water as currency is that the value of any particular unit of that currency would be consistent in relation to other units of the same currency, but would have extremely dynamic purchasing power depending on how thirsty the service provider or product merchant is. [Answer] Despite your very plausible practical ideas, water is not that great in either of the two functions of a currency, as a store of value or as a medium of exchange. However the Romans did use a consumable substance as currency, namely salt. That is where the word "salary" comes from. Of course it is less vulnerable to accidental loss than water is, as eharper256 said. Tobacco has also been used as currency, in colonial America, and cigarettes were an unofficial currency in prison camps in both world wars. So it can happen - but it usually only arises because something (often inflation) stops the usual options working. Your plot difficulty, then, is to create the circumstances which mean that water *continues* to be used as a currency. Possibilities include: a powerful person who is rich under the water economy enforces its continued use, or a religion or ideology arises which decrees that water is the only truly valuable thing and so must be used. After all it's not unknown in real life for societies to make bad decisions about the choice of currency! ]
[Question] [ A ship is sent through a wormhole to an unknown planet to create a sustainable colony. The colonists know that they won't have further contact with their home planet - this is a last ditch effort to save the species. An earlier question gave the number of colonists required as being anywhere from 80 to 300, but what about technical skill and knowledge? What professions and experts would you need to keep the colony alive? Medical personnel, engineers/mechanics, and botanists/biologists are the groups that immediately spring to mind. You'd also need a leader in place to keep everything running. What other important positions and skill sets would be required? Disregard the pilot and crew of the space ship for the moment - who would they need on the ground? The technology level of the initial colonists does not have to be sustainable. They can lapse into a pre-industrial level society. [Answer] You'd absolutely, positively need farmers. Possibly a lot of them--at least a significant portion of your colonists would need to be farmers primarily, or have some kind of agricultural and/or animal husbandry skills in addition to their primary skill-set. Food is paramount to survival, and if this is a last-ditch survival effort that requires the colony to become self-sustaining *fast*, you don't want to rest all your hopes for food on equipment that will eventually break down or wear out. This means your farmers need to be actual, dyed-in-the-wool *farmers*, not just "guys who can drive a tractor or run the autoharvester". Survivalists (hunters, woodsmen) of some kind would also be useful in the "food" (and shelter) capacity. While your botanists and biologists will be able to tell you *what* on the ground is safe to eat, you need people accomplished in hunting and foraging to *get* it for you. Additionally, they'd want to pass as much as they could of their skills on to the other colonists, which improves everyone's survival chances. And, in addition to engineers and mechanics, you'd want architects. Gotta be able to set up enough homes for your colonists once you've run out of prefab structures. (ETA: Burki wisely points out that civil engineers are probably better than architects; we don't want really snazzy homes, just working shelters.) More than anything, you'd want people who can do much more than just one single specialized job--you want jacks-of-all-trades. If the people sending out your last-ditch survival effort have the leisure to pick, they'd want to choose colonists who have multiple useful skill-sets that span the range of what's needed. A botanist who also has experience farming or an engineer who's also an outdoorsman would be the perfect kind of person for this. (Unfortunately, they'd also be comparatively rare, if the current trend toward specialization in our own society is anything to go by.) (Thank you to PipperChip for pointing this one out!) Interestingly, while most people remember her books for the dragons, Anne McCafferey actually does a pretty fair job in *Dragonsdawn* of showing just how much would go into setting up a self-sustaining colony that's meant to exist at a roughly pre-industrial level. Granted, some of her ideas about logistics (how much arable land it takes to feed GIANT FLYING MACROPREDATORS) are kind of silly, but she recognized that pretty much everyone would have to shift from highly specialized job roles like "botanist" and "engineer" to more generalized, mostly agrarian skill sets over the life of the colony. [Answer] **Short answer: a fair number of (mostly) youngish women** ## NO DIRT-FARMERS, AND NO CAVEMEN Without a real good Earth ecosphere match, you're going to **have** to be able to run an industrial civilization. You can't go caveman if there's nothing to eat. And there's no reason for there to be plants or animals that've evolved to be edible/useful/productive for aliens (ie: Earth humans). Or for Earth imports to be able to out-compete species on their home turf, in the ecological niches they've spent billions of years optimizing for. Unless you **know** that you're *only* going to be competing against blue-green algae/or whatever has made you a nice oxy-atmosphere - you better be planning on being able to sustain some level of technical civilization. Because you are specifically not taking enough people to wipe out a planet, and terraform it to be Earth compatible. As per habitable planet considerations, you're going to a world that has life, so there is free oxygen. You're not going to farm the dirt (or even have dirt if it's just oxygen-causing soupy seas), unless you have high tech tools. ## INITIAL POPULATION CONSIDERATIONS MVP aside, I think you're going to want 400 people/women (and preferably a really huge set of frozen sperm and eggs - and the ability to keep them on ice and do IVF, if not artificial wombs (might be doable right now, if laws were less draconian)). Btw, unless there is a reason, you should probably be taking mostly (90%? - ie: 40-80 backup sperm donors, preferably with different, surgically implanted second (and third!) testes) pregnant women as your colonists. Preferably varying durations of pregnancy so they're not all due at once. Preferably using sex-selection techniques to ensure 75-90% female fetuses for that first generation, also with both wide genetic diversity and narrow. In the West at least, there are usually women trained in every field. Very few fields have only male practitioners. You'll preferentially pick those, and you'll train those (if there's time). Civilization maintenance is another post, or more on this one later. [Answer] **Teachers**. So that knowledge is transferred to coming generations. Anything you would want future generations to know - language, mathematics, physics, history etc. no point in sending technical expertise if the knowledge isn't transferred, and without the basics it's hard to be become an expert. [Answer] It would be difficult to make a sustainable colony because specialization would be lacking. Our current earth is only possible because we have 6 billion people cooperating to produce things. Where you would have the greatest problem is advanced technology or technology involving large pieces of equipment and capital investment; that would mean computer technology, mining, farming and power generation would be the biggest problems. Making computer chips and power generators without large teams of specialists and resources would be difficult. Also, how would you mine metals and new materials? Mining is very capital and labor intensive. Without prospectors and mines you would have no way to get new metal. Mechanized farming is only possible with large factories making tractors and other complex farm equipment (harvesters, tillers, etc). The immediate problem would be **food production**. Without tractors you will be in trouble. You can farm by hand, but it would mean virtually everybody would have to be a farmer or farm hand. This would be the situation of a small isolated community. They would essentially be reduced to subsistence farming. Without a large infrastructure to support machine making (steel, oil/coal, chemicals), you are basically stuck living like a primitive caveman just to get enough food. You would need many thousands of people to support minimal mining and blacksmithing operations to get out of that. --- Let's just back up a little and ask, what would we need to do have a 1000-person colony that would not be living like cavemen or eskimoes (hunter-gatherers)? First of all you would need to bring materials and equipment: rubber, tool steel, glassware/optics, machine tools, generators and motors, computers. Lose any of this stuff and you are screwed. The biggest bulk would be the machine tools. You would need at a minimum: a lathe, milling machine, grinder, arbor press, hammer forge, anvils, dies of various kinds, files, gearing, abrasive wheels, etc. You would be talking several truckloads of machines at a bare minimum. You would need at least 50-100 people to operate and maintain all these machines. You would need another 50-100 people to focus on mining, primarily iron which you absolutely must have a source of. You will start to run into trouble with tooling. Your cutters will wear out and you need tool steel to replace them. That means you need nickel, chromium, manganese, and moly, if not vanadium. Getting these materials without big mining operations would be problematic. For example, nickel tends to be a deep earth metal so requires a big operation. You would probably need 200 of the 1000 to be doing nothing but farming. You need 50-100 doing irrigation, water supply and sewage. You would need about 50 people doing power management, which I guess would be water based. You would need another 50 or so doing pottery and container making. You would need another 50-100 doing fibers, meaning rope, cable, wire, gathering and making. Another 50 doing garments, gloves and protective gear. You would need at least 50 women giving birth and doing child rearing and another 50 teachers and trainers. Are we running out of people yet? [Answer] I added edits how to handle situation in fairly hostile planet (no immediately edible animals or plants), and with fairly limited crew size. **ALL colonists would be young women PhD biologists (with few mechanics/electronics engineers added) in their twenties and early thirties.** Smartest ones, very healthy, genetically screened. Few genius teenagers, to stagger fertility (after age 40 fertility diminishes and chance of genetic diseases increases dramatically). And many (tens of thousands) samples of frozen sperm for later, to maintain genetic variability. Would not make sense to waste such limited space on men, if you can grow them up later - when you are sure you can feed them. Not sure why and how is your limit on number of colonists: Is it total weight of the cargo in spaceship? Because if weight is the limit, **it could make sense bring less crew but more cargo which would help to establish colony faster** (because cargo does not need food and life support during the flight). And spaceship can provide life support after landing too, for exactly same number of crew. If planet has breathable air, it has some life (which created oxygen), and **likely some kind of plant and animals - at least algae and fungi.** So you can assume you can harvest such resources for needs of your colony, and consume them after some transformation. From original post, it is hard to guess how different the biology of host planet is, and how much transformation will be necessary. Depending on natural resources, you can support such small population by hunting/fishing (which require easy to gain skills) for first decade (kids don't eat much - spaceship can provide for same population), while working on developing basic industrial technologies. You need also a **way to explore planet fast, to land in a place with lots of natural resources. Your aim would be resources for steam age technologies.** Coal and iron, next to reasonably fertile plains. You would need to observe weather and seasons, and be ready to relocate few times - which should not be too hard, because for first at least decade you would live in spaceship anyway. Taming animals also can be established quickly: [experimental domestication of silver fox](http://en.wikipedia.org/wiki/Domesticated_silver_fox) done in 50 years (20 generations). You need easy source of food, like insects or fish. You will include also huge library, so young crew-members can learn from experience of others on Earth, and not from own mistakes. Depending on how much time you have, you may even **try to run simulations of such settlement on Earth**, with colonist trained in developing steam-age technology from scratch: outside world provides them raw materials, but they need to figure out how to build needed tools, and manage community and not to kill each other. And they have whole tool-building factory on spaceship (and lots of metal). So **elder colonist would be best veterans of such training, who did such boot-up few times, and youngest at least once.** So they could be preparing for such mission for a decade or more. If you have few decades, you can set up whole culture about that: mothers training their daughters to be experts in necessary technologies, preparing lab technologies which are automated and easy to repair, etc. Think about Ender's Game Room, but for female double major PhD biologists and mechanical engineers. If you are selecting only one of hundred million, you can be very picky - and people will be motivated to learn necessary skills. **Farming and hunting is a basic skill which any person preparing for such mission can pick relatively quickly. Plant biologist will naturally cross-train as farmer, and animal biologist or geologist as hunter.** You need also "tool people" like mechanical engineer, builder, miners, chemist. And medical personnel, especially gynecologists and psychologist, including children psychology. All women of course. If you have really long time to prepare, many can be children who were born and raised in such simulation camps on Earth. Raised from sperm of men who have very gifted daughters, by teachers trained for such situation (no male examples). There is a danger that women on such colony would like life without men, and would not raise any until there are many thousands of women - planet of Amazons indeed. :-) **In worst case scenario, none of local lifeforms are usable for humans,** and you need to develop ecology. You will need more biologists (or more time). They will have to **design bacteria which can digest local lifeforms** and grow and be fed to higher life forms usable by humans, like: algae, fungi, then insects, chicken. It will be long slog, **might take several generations of (all female) researchers to develop necessary technologies.** During this time, colony would be supported by original life support system from spaceship (powered by solar energy), and would not be able to grow numbers beyond what life support system can feed. So if you are very unlucky, and very limited, you have crew of say 100 female biologists (few cross-trained in medicine) **supported for several generations ONLY by life support from spaceship,** trying to figure out how to use local life-forms to sustain humans. No men needed, focus 100% on research and training next generation. Women get artificially inseminated to born new generation of girls (one replacement girl each) to train them and continue development of ecology until they figure out what grows and can sustain the colony. Likely girls will have to prove themselves to be smart and team players very fast (IQ test by age 6), or be disposed of (used for human experiments) to be replaced with more promising sibling. It will be very brutal, but such planet will not be a place for weak - or even for average. Until we can feed everyone, we can afford to feed only the extraordinary - or die out. **Only after basic farming is established they can consider increasing size of the colony** beyond what spaceship life support can provide for, and spend resources on developing additional technologies (after learning them from ship's library), mining resources, building outside structures, growing the colony. Even then, you would want to **try local food only on few volunteers (human experiments again)** to see longer-term consequences before you commit whole colony to new food. You have no margin or error to i.e. local food in some way causing birth defects after 20 years of consuming it. So likely **young population (before and during fertility) will stay on original Earth food** for even longer, after older (past 40) will try to "go native" - and possibly suffer the consequences. **Genetic diversity is not a problem at all,** you may have several thousand samples of sperm, to start using in different generations. If you have time, you can even select fathers by ability and skill: science skills, engineering/manufacturing skills, fierce fighter skills, as expressed in their daughters. With frozen sperm, problem is not genetic diversity but sustaining life in the colony. If you can have some **experts in hibernation,** that could help: you will thaw them when you need expertize, and refreeze then in between. Will be extremely harsh world, with very strict morale about living only to contribute to survival of the colony. No slackers. You need **defense to protect your colony.** Best weapons would be something where you need to add just energy (from solar) and not chemicals (which you need to bring with you [expensive cargo] or mine and manufacture locally [distracting you from survival]. Mechanical catapults using local rocks fits the bill. You know it already, but with such stacked deck, you have **VERY small margin of error, and any small mistake might wipe out your colony.** Sending multiple spaceships will make much sense. it will also limit consequences of choosing wrong landing place - because even if relocation will be possible, will not be simple nor easy nor cheap. **Absolute minimal limit might be as little as maybe dozen female biologists/engineers,** with spaceship capable to support them for many decades until they will develop ecological way to support bigger population from local resources. Really tough. Could be good story. [Answer] Since an Earthly biosphere wasn't specified, I would say a closed ecosystem and the skills and materials needed to run such a thing would be the absolute minimum. Explorers can exit the "bubble" to discover what resources are there (so you would need geologists, prospectors, biologists and so on to catalogue the resources on your new world). Finally, trained technicians who understand mining, smelting forestry, agriculture and all the other trades needed to utilize these resources, so you would need a fairly large colony (to contain all the skill sets), some form of advanced database and learning system to teach the people new skills if you have a small population, or some form of advanced AI to teach people and run machines remotely would also be needed. If this seems pessimistic, consider the essay I, Pencil by Leonard Read. The accumulated knowledge to make a typical pencil in the modern world is spread among so many different people and different places (gathering raw materials, the logistics chain to get them to the factory, the various skills needed to convert the raw materials to a pencil and the logistical infrastructure to get the finished pencils to market) that no single human being knows all the steps needed to create a typical pencil and get it to the end user. Of course, you could also go the other way and send an enclosed ecosystem as a space colony and enough technical equipment to mine asteroids and moons to replicate the bubble as many times as you like, although once again a vast pool of either people or knowledge would be needed. Go straight to a space based civilization and ignore the planets (or leave them for later). If you can do that, the reasons for leaving the initial solar system might well be moot, unless you have to leave because your Sun is going nova or the solar system is being bathed in a gamma ray burst. ]
[Question] [ Is there a way to make a planet invisible naturaly? I dont want the entire thing to be clear, but have a natural "field" or something that prevents the planet from being seen (or makes it much harder) from the outside. It should still allow someone to get to the planet. It only needs to be invisible to the naked eye and some levels of lower tech (like early radar and thermal vision), but it can be visable to the higher level technologies. I would prefer it to stay invisible from all angles until the "person" passes through the "field". The "field" would be either in the atmosphere or the stratosphere (but, if there is a way for to happen (but the field had to be somewhere else), then the placement does not matter). The planet would probably be in or near a nebula. [Answer] # How to Cloak a Planet The basic idea behind cloaking is very easy; bend the light rays around the planet in such a way that you restore the light to a path it would have traveled *if the planet were not there*. This sounds much easier than it actually is. There are only a few ways you can do this. # Gravity? Gravity bends light, and so it can theoretically do the trick. In practicality, gravity as we know it cannot perform this. This is because the amount of gravity you need involve black-hole sized masses, and we would no longer call that a planet, but a black hole. So gravity won't work. # Metamaterials Most "cloaking" devices nowadays involve metamaterials ([see this academic article!](http://onlinelibrary.wiley.com/doi/10.1002/adma.201202624/abstract) and [this list from wikipedia!](http://en.wikipedia.org/wiki/Invisibility#Practical_efforts)), materials which are composed of other materials but whose structure is arranged so that you get specific properties. Yes, you can get metamaterials to redirect light, absorb light, or simply prevent a lot of scattering from your object. Essentially, you can use them to cloak things. Specifically, you're looking for materials with a negative reflective index. Your atmosphere will need a very specific arrangement of its layers, one that one likely be destroyed by any amount of weather. Also, it looks like this layer of atmosphere will be made up of metals. Not that you can't have an atmosphere with metallic elements in it, it's just very unlikely. # Birefringence or "The Wonders of Calcite" Some researches have been able to use [calcite](http://www.ncbi.nlm.nih.gov/pubmed/21405275) to [cloak macroscopic objects](http://www.ncbi.nlm.nih.gov/pubmed/21285954). This is due to a special property they have called [birefringence](http://en.wikipedia.org/wiki/Birefringence). In theory, your atmosphere can have some special arrangement of layers to cause this birefringence and other conditions needed to hide it. Alternatively, you can be in a nebula which produces such a layer around the planet. # Surface Cooling You could, in theory, cool the surface of your planet such that it does not give off much light. This may not jive with your concept of how this cloaking should work, but I'm mentioning it here. Essentially, you cool an object's emissions from [blackbody radiation](http://en.wikipedia.org/wiki/Black-body_radiation) enough that you can't distinguish it from the surroundings. This would be very, very cold; the planet would be near the temperature (on the surface) as space. # Some Issues with Cloaking 1. If you're bending all the light waves around a planet, the planet itself doesn't get any light on the surface, because that light is being bent around it. This makes living life on the inside of your cloak hard. 2. Sir John Pendry, a renown physicist who is considered a father of metamaterials, thinks that [this is impossible](http://spie.org/x57588.xml). He doubts you can get enough of a material to hide anything more than a few centimeters across. Hiding a person, much less a planet, is a fantasy to him. 3. The [atmospheres of exoplanets](http://en.wikipedia.org/wiki/Exoplanet#Atmospheric_composition) which we know of do not contain massive amounts of metals, which many metamaterials need to work. Of course, the sci-fi genre has never been totally stopped by this before. Just realize that this boots your planet out of the hard sci-fi genre. 4. The fact that humans see a spectrum of colors, not just one, prevents many cloaks from ever taking off. You may be able to hide from one wavelength, but not the others. Calcite seems to avoid this. I have focused on visible light, although invisibility cloaks for IR and microwave light exist. In fact, some [tanks](http://foxtrotalpha.jalopnik.com/is-polands-stealthy-pl-01-the-tank-of-the-future-1554395391) supposedly can do this in IR. [Answer] You can cover the entire planet in an artificial structure that has very low reflectivity. For example you could cover the top in solar panels covered with material that absorbs the frequencies the solar panels do not use. Then use the solar power to cool the air trapped above the structure with heat pumps. If the heat was pumped into large gas bags, they'd function as hot air balloons and give aerostatic lift. It would probably be easier to just have optics that guide sunlight on top to inside the planetary structure. Such lens/fiber optics already exist, so probably could be mass produced efficiently by anyone trying to "hide a planet". A combination system where some frequencies go to photoelectric systems and parts to optics that guide them to the surface might be possible. It might also be possible use solar thermal to drive the heat pumps directly. Systems where a small "hot area", easily achievable by focusing sunlight, is used to drive a cooling cycle have been used for refrigerators in areas without electricity. Photoelectrics might be simpler though. Height of the structure is problematic as you would want it be above as much of the atmosphere as possible and certainly above the mountains, but it is easier to build even a floating structure closer to the ground. Maybe that should be left as an implementation detail? The system as described would essentially turn the planets albedo to be very close to zero,trapping all the light inside. This would make the planet very difficult to detect and probably be sufficient to answer the question. Two issues remain though. A minor issue is that this would leave a shadow. There would be a perceptible dip in the luminosity of the star when the planet transited it. The planet would also still have a gravitional effect on the star, causing it to move slightly. This is also detectable from interstellar distances. A **MAJOR ISSUE** is that with the planets albedo dropped to near zero, the planets temperature would rise rapidly and by a large amount. First solution is to have a wide enough orbit. Planet on a wide orbit has lower gravitational effect on its star and also has habitable temperature even with much lower albedo. A previously habitable planet would need to be moved to a far orbit, a challenging engineering problem of its own. More practically otherwise inhabitable ice ball with naturally correct orbit could be terraformed to habitable temperature. This would probably be accompanying with use of artificial lights inside the cloaking structure to maintain visibility with reduced natural light. Second solution is to radiate the heat selectively in a specific direction and with specific spectrum. Generate hydrogen plasma with temperature close to that on the surface of the star and guide the resulting radiation from a small opening in the structure to direction opposite from the star. From another star system this would hide the tell tale dip in the luminosity of the star and give a convenient place to dump lots of excess energy. Doing this would require a way to take excess heat from the planet and convert it into heat of the hydrogen plasma. Probably possible but it would have to be ridiculously expensive. Finally, the best way to hide is to be where nobody is searching. Have your home far from those annoyingly bright stars and hide in the darkness. An orbit in the Kuiper belt might be enough unless you want to hide from somebody with permanent presence in the system. [Answer] It really depends what range you want it invisible from. "From the outside" is quite a large range of values. I'm assuming "orbit around the star" (quite hard) rather than "orbit around a nearby star" (much easier) or "orbit around the planet itself (impossible)". If you want a natural effect, probably the best you can do is to hide it the same way that islands were hidden in tales of yore - in a cloud. A planet is defined as an object which has cleared its orbit, so technically, just by cluttering the orbit, you make the planet *literally disappear* - there is *no longer a planet in that orbit*, by definition. But there's still one hell of a big rock. From a large enough distance, it'd be enough to fill the planet's orbit with enough high-albedo "chaff" that the planet would not be comparatively noticeable to instruments either when crossing the sun ("eclipse"), or when reflecting it ("full moon"). The closer you need the non-detection, the more dust you need. A light mist will conceal an island from ten miles out, but you need a pea-souper to conceal it from ten yards! Now, downside is, the dust will make the star look really weird. "A star that age, with so much dust, such thickly-populated rings? How strange." The dust will also affect the planet, reducing incoming sunlight, and falling constantly into the atmosphere in some brilliant and beautiful eternal aurorae, perhaps laced with shooting stars of the larger particles. The planet would be better protected against radiation, and could possibly be heated by the aurorae at least to some extent, but I'm not sure how effective that would be. There'd also need to be something to produce the dust, which might in turn be detectable. [Edit: If you only need to protect from viewing directly in line with the planet's orbital plane, then you don't need dust in the planet's path - you can have a larger ring *outside* the planet, like our asteroid belt but much thicker, which would obscure it sufficiently, from that one angle.] [Edit2: Note that ring thickness is unstable, but rings can be cabled, and if we're assuming that the rings can be produced, they can be renewed anyway. A solid ring (Dyson ring) resolves the stability problem but becomes a world more complex to create, and creates its own stability issues. And all this is moot in the longer term anyway, since as @2012rcampion commented on another answer, with sufficiently sensitive instrumentation, and long enough study (at least one year, poss many more), merely observing the motion of any visible planets and the sun should be enough to find a planet in the mist even from another star.] ]
[Question] [ I have been reading about [mutual assured destruction](http://en.wikipedia.org/wiki/Mutual_assured_destruction) and [deterrence theory](http://en.wikipedia.org/wiki/Deterrence_theory) on Wikipedia, and it got me thinking. What would it take for some of the countries in the world to actually destroy one another, if deterrence theory theoretically prevents this? The world is set in the present, but one (imaginary) country is threatening other countries. They are mean and want to rule the world. They are hungry for power, so they would prefer to attack larger countries. They have plenty of nuclear power to do so if they weren't being threatened back. I would like a method that is completely intentional (no misfires or miscommunication). This is important because my imaginary country is very evil. [Answer] Hard to call it an answer...but create a multinational corporation, fund it (but hide the funding) and have it create arms in each nation it wants to attack. Launch the nuclear attacks using the corporation so they seem to be coming from 'rogue' elements instead of the evil nation itself. Fits in the subversion category Oldcat comments on...idea is simple, make the attack extremely hard to trace back to you and instead to some faceless entity. Other option is to reach a nuclear arsenal 'first strike' state like America has where you could theoretically nuke every last site that could retaliate back on you at once. Tons of risk in either case...if it's traced back to your evil empire, it's quite likely that another nation will respond in kind. Possible that wild accusations alone would make a nation that has been struck with nuclear weaponry strike the evil nation anyway. [Answer] One country would have to want to destroy the other more than they wanted to be destroyed, or feel fairly certain that the other country was going to destroy them. The first case could happen, for example, to an extremist nation that was losing a conventional war. Instead of losing, it could be seen as favorable to lay waste to the other country with nuclear weapons. If the other country retaliated, MAD would happen. Alternately, such a country could be seeking to 'destroy the infidel' without regards to its own integrity. I could see a group like IS carrying out such an attack. The second could happen if the country felt certain that the other country had already either nuked it or launched a nuke at it. Such an attack, even if truly committed by a third party intent on starting a war, could lead to retaliation and MAD. [Answer] The weakness of MAD is that using it is by definition a suicide, so as long as your enemy does not believe your actions threaten their existence the threshold to unleash the nuclear weapons is quite high. During the Cold War this showed in a large number of proxy wars in what was usually called the third world. In general the concept is to have a clear idea what are the triggers for the other side and then do something else. Bonus points if your idea is related to reality. In practice, if you want the evil guys to lose you can model their leader after **early** Hitler. He started with reoccupying Rhineland which basically everyone agreed was justified even if potentially a dangerous sign. Then unification of Austria, which nobody could oppose too much as the Austrians had historically been considered Germans. Then Sudetenland which Hitler was able to get away with because the borders created after the war were still kind of artificial **and because nobody else wanted war.** Which as I mentioned is the weak point of MAD. The reason this is a losing strategy is because it is a dead end. You get away with it once on some relatively minor issue and then everybody is seriously thinking that they'd might have to pull the trigger if "that crazy person" doesn't stop. And stopping will be very hard with your confidence sky high and everybody telling you what a great leader you are. And since nobody wants to trigger a war, they'll avoid anything provocative, or with other words are looking weak and clueless. If you want the bad guys to win model the leader after Bismarck. Everybody knew Prussian militarism and Bismarck were dangerous and must be contained. It didn't do them any good. For example in your scenario typical leader would see themselves surrounded by enemies and act accordingly. Pseudo-Bismarck would realize that divisions such as allies and enemies are largely meaningless as they depend on the situation and the situation is influenced by your own actions. In the correct situation your steadfast enemy would end up neutral or even be on your side. Typical leader would act tough against enemies to avoid being taken advantage of and the enemies would close ranks against him. Pseudo-Bismarck would have no need to act tough and would freely engage with anyone willing to talk with him in order to keep the politics fluid and complex. Read exploitable. Typical leaders react to unexpected events by playing it safe, doing the expected, and avoiding mistakes. Pseudo-Bismarck expects the unexpected to happen, can predict what other leaders will do in response, and always has several goals he can push forward in the opening created by his potential opponents being committed on a strategy he can predict. I could go on, but somehow I doubt you want the evil empire to win and need more detail on this alternative. Pseudo-Bismarck would not let the world go MAD, pseudo-Hitler would almost guarantee that world will go MAD. Although having a player like that dominate the scene does create chaos when he is **removed**. You could give the evil country a previous leader who raised it where it is now thru such diplomatic maneuvers and a current leader who tries to play the same games but fails with catastrophic consequences. World war one was largely created because politicians were playing political games and made a web of commitments so complex nobody could control the situation. Bismarck, or anyone with **any** sense, would have simply reinterpreted any agreement that potentially triggers a war of that magnitude and instead negotiated a peaceful settlement that just happened to be in his advantage, but unfortunately most leaders react to complex situations by following what is expected of them so that they do not end held personally responsible for the mess. And that means following the agreements and letting the chain reaction propagate. This would be a feasible way to go MAD, I think. [Answer] 1. Simply give your nasty country something which their leaders *think* will allow them to survive the counter-strike, such as a missile shield (prevent the missiles arriving in the first place) or a load of very well-stocked bunkers. It wouldn't work for exactly the reasons that @tls cites - [Nuclear Winter](http://en.wikipedia.org/wiki/Nuclear_winter) etc, they'd be left living on a cinder - but all that you need is for the leaders of the Bad Country to *think* that it'll work. For example, the leaders of the Bad Country have executed half their scientists and all the rest are afraid to stand up to them. Nobody wants to say "no" to a dictator. 2. You could also consider a launch authorised not by the country's leaders, but by someone else in the chain of command. Maybe they're suicidal and they've decided to go out with a bang! See also: [Almost Everything In "Dr Strangelove" Was True](http://www.newyorker.com/news/news-desk/almost-everything-in-dr-strangelove-was-true), Eric Schlosser, The New Yorker, 17 Jan 2014 > > With great reluctance, Eisenhower agreed to let American officers use their nuclear weapons, in an emergency, if there were no time or no means to contact the President. Air Force pilots were allowed to fire their nuclear anti-aircraft rockets to shoot down Soviet bombers heading toward the United States. And about half a dozen high-level American commanders were allowed to use far more powerful nuclear weapons, without contacting the White House first, when their forces were under attack and “the urgency of time and circumstances clearly does not permit a specific decision by the President, or other person empowered to act in his stead.” Eisenhower worried that providing that sort of authorization in advance could **make it possible for someone to do “something foolish down the chain of command” and start an all-out nuclear war**. But the alternative—allowing an attack on the United States to go unanswered or NATO forces to be overrun—seemed a lot worse. > > > ... > > > Despite public assurances that everything was fully under control, in the winter of 1964, while “Dr. Strangelove” was playing in theatres and being condemned as Soviet propaganda, there was nothing to prevent an American bomber crew or missile launch crew from using their weapons against the Soviets. ... Even Secretary of Defense Robert S. McNamara privately worried that an accident, a mistake, or **a rogue American officer** could start a nuclear war. > > > ... > > > A decade after the release of “Strangelove,” the Soviet Union began work on the Perimeter system—-a network of sensors and computers that could **allow junior military officials to launch missiles** without oversight from the Soviet leadership. Perhaps nobody at the Kremlin had seen the film. Completed in 1985, the system was known as the Dead Hand. Once it was activated, Perimeter would order the launch of long-range missiles at the United States if it detected nuclear detonations on Soviet soil and Soviet leaders couldn’t be reached. > > > 3. The movie [Crimson Tide](http://en.wikipedia.org/wiki/Crimson_Tide_(film)) (about a nuclear submarine) contains an interesting scenario: the sub receives orders to launch its nukes against a Russian nuclear silo which has been taken over by terrorists and is preparing its own missiles for launch (the movie is silent on why the Russians can't just bomb their own base with conventional weapons, but presumably there's a reason in there somewhere). Bad People taking control of nuclear weapons - and perhaps triggering a counter-strike - has all kinds of fictional potential. Crazy People even more so. Many (most?) of the Bond movies are based on this premise. Or just make your Bad Country's leaders Crazy as well as Bad: problem solved! :) [Answer] It is a dilemma. It suppose actors will act in a rational matter. A rational actor will not use nuclear weapons unless he is 100% sure this will destroy his enemy. Since it's not possible, he know there will be a counter-attack and that the enemy will just throw everything at him. And there is also the environmental risk of using a lot of nuclear warheads in a short amount of time. **But actors are not always rational.** * Urgency/lack of time to decide on a plan, lack of information, the feeling that the other actors are unpredictable (that is very common) emotions and other factors will play against the protagonists. One might consider a preemptive strike against the enemy even if he is not sure it will destroy all possible threats of retaliation. It might at least give him an advantage. > > If China lost 300 million people in a nuclear war: the other half of > the population would survive to ensure victory (quote form Mao > Zedong). > > > **Total war:** Another possibility * A total war is when all the societies are dedicated at only one goal:war. War invade every aspects of life and this is also reflected in how states are waging them. The goal is not to take the capital like it once was but to destroy the enemy at all cost. There was a quote about the last stand of the Third Reich that said that the country would be better to destroy itself than to surrender to the enemy. They poured every man and women and every resources they had. So, possibly as a last resort, they would not hesitate to use weapons of mass destruction even if it meant their own destruction. Is that irrational? I don't think so, if your sure to lose anyway. [Answer] Possible ways: * Waiving self-preservation. The typical reason would be religion ("We will kill the infidels/heretics/unbelievers! If they destroy us too we do not care because we will go to Heaven!"). In practice, even in the most religious countries/movements, most of the people want to stay alive. The most dangerous issue would be a minor, radical branch seizing a nuclear bomb and initiating an exchange that escalates between the countries. * Last ditch effort: Country A is advancing in country B, with the declared objective of slaughtering all of country B's population. Country B may consider it safer to start using nukes than to suffer defeat. Even in that case, I would expect a first wave of "limited" nuclear war (targetting army/air/naval bases, infrastructure, etc.), in the expectation that country A will be hurt to retreat but not enough will not retaliate with total atomic war and mutual anhilation. After that first wave, all bets are off. * Miscalculation: the most viable. Two ways a) Country A things it can win by striking first. It will be even better if the advantage is known to be temporal (let's say, their spies have got the codes to disable country B nuclear weapons, but those codes change each month), because it gives an incentive for not losing that advantage (if the advantage is permanent, only its threat will be almost as effective as the real attack). b) Country A things country B is about to get an advantage that allows them to strike first. Think of Cuban Missile Crisis. c) Apart from that, the usual fog of war/misconceptions about how different . USA may think that conquering North Korea is just a minor issue, but forgets that China does not want Western armies at its borders, and the conflict escalates. Make that happen with something that is of vital interest to one of the parties, and the probability that such party considers using nuclear bombs skyrockets. [Answer] Some other possibilities: * Learn someone else's theory and forget the reasoning. For example, the leader might just wanted to play [Chicken](http://en.wikipedia.org/wiki/Chicken_%28game%29) and threaten to use nuclear weapons. They already used some conventional weapons somewhere and made believable plans for when to use nuclear weapons. One day, the leader suddenly dies and didn't leave any clue of what he really wanted to do. At this time, the scenerio that they should use nuclear weapons happened. And Other countries seemed to be planning an invasion (at least they believes so, presumbly not using nuclear weapons). His fanatic followers have no choice but use the nuclear weapons. One advantage is, after investigation, they will still think the evil country deserves a nuclear strike. * They are in a world "without" nuclear weapons. Humanity decided to destroy all nuclear weapons somehow. Then one country had some advanced technology to preserve some nuclear weapons and never let the other countries know. What they don't know is the other countries had this technology, too, and that's probably why they agreed on this treaty. * They want to destroy all the advanced technologies. They just want to let everything destroyed, everywhere in the world. Maybe they should use weapons with less radiation. People may try to hide in unknown places. They can even warn people in other countries to hide at the beginning. But the power, heavy industries, etc, probably won't survive. And that's all they wanted and probably the point of why they are evil. * Alien-like enemy. Almost every country agreed that they won't use nuclear weapons. But one country or country-like organization, which everyone else didn't even noticed, suddenly declared they had, or they gained control of huge amount of nuclear weapons and refuse any communication. Other countries agreed they will use nuclear weapons for the same purpose, but underestimated how big it is. Everything just happened before the evil organization declaring they really wanted to use them. [Answer] Evilopolis wants to destroy (or conquer) Paniniland. Pizzaland has some cultural divergence with Paniniland but they are at peace. Evildoer pay someone to bombard Paninari with mozzarella and tomato. Someone claims to be Pizzaiolo. A war starts between Paninari and Pizzaioli, fomented and financed by Evildoers. Eventually Pizzaioli throw a calzone ripieno and Paninari retaliate with Pound Whopper. It's a carnage. Evildoers eat it all, pizza & panini. (have I read this somewhere? Sounds familiar) ]
[Question] [ In relation to [this](https://worldbuilding.stackexchange.com/questions/1042/how-would-a-force-field-dome-over-a-city-effect-the-weather) question, how could I create a force field dome over that city? Specifications of the city: * 10 x 40 km on the surface * 1 km in height * has a city wall of 100 m all around the edge. What the force field needs to do: * Hold against artillery barrages * block line of sight in the city * does not let anything in or out when activated * round edges and 2-3 km in height so inside flight is possible What is, as far as science gets, the closest to real technological solution? I want technical buildings I need to do this, I am sure I need some sort of pylon but what else? [Answer] If you're looking for hard science, you're out of luck: there are no known ways to create a non-material barrier that will stop projectiles or other large objects. You might be able to create a physical shield from steel or near-future composites that can be opened or closed as needed, but that would be a rather epic engineering project. [Answer] As far as hard science goes the closest you'll come to repelling large objects is warping space. Something along the lines of an [Alcubierre drive](http://en.wikipedia.org/wiki/Alcubierre_drive) I'd imagine. According to the wiki page it would exert large tidal forces. Tidal forces can get pretty scary (see [Roche limit](http://en.wikipedia.org/wiki/Roche_limit), keyword disintegrate). Of course that doesn't stop energy weapons but if your atmosphere has a decent amount of Hydrogen I would assume the forces exerted by the force field would produce enough pressure to make it solid. As solid hydrogen is a metallic superconductor you get your energy shielding for free: Faraday cage, high reflectance, perfect heat distribution, etc. As for the specific differences of the field and whether you would indeed achieve enough pressure is more maths than I care to work out. I am imagining a rotating field so that your tidal forces occur even for a direct shot. [Answer] This seems impossible with our technological level, but there's ways around those limitations if we give ourselves a bit of artistic license. Here's my picture of the dome shape from your other question: ![dome shape](https://i.stack.imgur.com/JDFJ5.png) We need a force field to cover that are and be essentially impassable. I can think of two ways to do this - an actual plot-field, which would be hard to explain but actually is a "field" and an alternative approach using a combination of a physical dome, with gaps that it can fill with fields or material to give the same effect. ## Plot-field Since we need a force-field that would block *everything*, we basically need it to behave like matter. Very tough matter, but matter nonetheless. That means getting through the field should be no different than trying to break through titanium or something like that, albeit thick and tough titanium that can fix itself. I don't know of any plausible physics that can create such a field - if we could do that, we could create matter out of thin air. However, we can assume you civilization has mastered the means of creating fields that mimic the way that matter works and can project them. Considering the shape of the field, we'd have to place the generator very far underground to get the intended result (it's effectively a shell of a large sphere). We could alternatively place multiple generators across the city's foundations and create a composite field that would have approximately that shape, but that would be crude for someone who can already create matter fields and placing it underground gives the city the massive advantage of protecting itself *from all directions* even underground - in other words, enemies can't even dig a tunnel under it to get around the shield. The problem is, we can't just have a spherical field underground because, to get this dome shape, it would have to be 72km underground: ![spherical shield](https://i.stack.imgur.com/FaSZL.png) [link to plot](http://fooplot.com/plot/3f5az2hxm0) So we'll have to make it extend from a plane under the city, much like this: ![underground source](https://i.stack.imgur.com/DaEPj.png) [link to plot](http://fooplot.com/plot/3843hxav6g) If shaped this way, we can place a circular plate under the city about 900m, to give us the needed field. It doesn't end there though because if we just have a field, activating it will affect *everything* in its range - it won't just create a nice dome. If this was designed the repel matter and we power it, it would make the entire city explode around it. So we need to carefully shape it. ![double dome](https://i.stack.imgur.com/Av5wh.png) Since we're assuming exotic fields that don't exist yet, lets assume an exotic mechanism for them to work by: they turn electrical energy into tiny vortices and give them spin, making them matter particles (that's pseudoscience technobabble, but hey, it's a force field :P). The red and blue fields create spin in opposite directions, so they cancel each other out. To create matter, they need to reach a threshold, so if the field strength is too low somewhere, nothing happens. By adjusting the red field's strength and compensating with the blue field, we can adjust the thickness of the field's dome. Using this arrangement, we can cancel the field out inside and prevent the city from exploding. What form would a generator of this kind take? Here's an idea: ![orbitals](https://i.stack.imgur.com/Yp8kc.png) The "4f" arrangement seems nice. Just make it spin really fast on all axes. ## Physical dome A probably preferable mechanical solution could be accomplished by having a deployable dome, that forms a mesh when deployed - then it fills the gaps with matter somehow. I'm thinking of something like this: ![Missouri botanical gardens](https://i.stack.imgur.com/2C2ok.jpg) But of course, ours would be a lot larger and flatter. Your dome could deploy from the perimeter of the city and once in place, extend titanium panels to fill the gaps. Obviously, it would need some other form of exotic technology to expand so much - perhaps the city has huge stores of molten titanium under it and using some shaping trick it alloys the titanium with tungsten (to give it a higher melting point than plain titanium) and then funnels more titanium through the bars, suspending it through magnetism or something, until it cools into titanium plates. [Answer] Here you can use an actual physical field to act as a force field - in certain scenarios. Let's say you want to stop a single particle. What can you do? You can trap it. Not deflect it, in the sense you mean, but make it get stuck in a single point in space. Here's how: If the particle has electric charge or is magnetic, you have a solution: Use an electric field to attract the particle. If this is the primary influence on the particle (discounting gravity), the particle will eventually stop moving in whatever direction it was going before and be "stuck" in the field. The same goes for magnetism - in fact, this might work better for larger objects. Let's take a look at the requirements for the force field: * 10 km $\times$ 40 km * 1 km tall * Mounted on a 100-meter-high wall * Dome-shaped Okay, that doesn't sound too hard. . . Lets face it: a single magnet at the center of the city isn't going to do squat to an object at the edge of that big an area. 400 square kilometers is nothing to sneeze at here. So you definitely need multiple magnets. My first thought would be to stick a bunch of [electromagnets](https://en.wikipedia.org/wiki/Electromagnet) on pedestals around the area, but that's a bit of an oversimplification. Your everyday junkyard car-picker-upper won't do the trick. So we'll take a step up and go to [superconducting magnets](https://en.wikipedia.org/wiki/Superconducting_magnet). These are a lot more powerful. They're also fairly big and need a lot of energy, so maybe we'll change the "pedestals" to small buildings, complete with a power supply. The bit about the dome is tricky. A magnetic field permeates throughout all of space, but the field gets weaker as it gets further away from the magnet. In other words, having a bunch of magnets lying in a plane won't produce a lot of force on a particle somewhere above the plane. So in order to create a dome-ish shape, the pedestals should slowly gain in height as they near the center of the field. So to create this field, simply mount a bunch (hundreds, if not thousands - I should have mentioned that earlier) of superconducting electromagnets on some pedestals of varying height throughout the city, hook them up to an enormous power supply, and turn the thing on. [Answer] **A Dome of Drones** I will go with a very big swarm of drones, interconnected and fully autonomous. Not strictly a "force field" but give answer to all requisites: * can cover all city * can block vision: emitting strong light * can block unwanted objects: drones can be armed, or be explosives, and swarm towards any aggressive incursion/shell to block/destroy it * can let pass "identified" objects in/out From the city, perhaps it will not even visible the composition of the dome or his nature. Some kind of hangars should be placed somewhere (on top of the city wall?) to allow drones to charge / repair / replace losses. [Answer] Security experts recommend "Defense in depth", and "Multi-layer security". Plus, it makes the system more interesting to describe to the reader. So you could use several different devices or systems to achieve all your ends. While all a bit scifi-esque, here are some ideas at least a little less of a hand-wave than "forcefield". > > Hold against artillery barrages > > > * Automatic border-defense lasers (like Reagan's Star Wars strategic Defense Initiative) * Intercept missiles (like the Patriot missile defense system) * EMP and scramblers to mess with targetting systems for guided missiles * Strong electromagnetic fields to deflect rather than merely stop. Not necessarily redirecting entirely away from the city, could just direct into catchers or save zones every km or so. * A physical dome barrier shield, could expand out of rooftops, if the buildings are built at the right heights. Depending on its strength, could protect from minor shrapnel (a chickenwire dome) or the full bombardment. > > block line of sight in the city > > > * Charged particles could be held in a kind of smog over the city, which could, with the right kind of particles, be impenetrable to most or all wavelengths. Charging the roads differently or venting clean air out of regular vents could keep ground level clear and the smog at roof level and above. * A physical dome barrier, even if just black plastic. > > Does not let anything in or out when activated > > > "Anything" is a big word. If you nuke it, will it let the blast through? The radiation? sunlight? Air? * Some defenses could be built into the buildings by building regulations. So, if all housing A/C is required to be tied into the municipal air supply, so to protect against airborne radiation, chemical or biological attack, just go indoors and close the door. * Vehicles, tunnels and covered roadways and walkways count as indoors, especially if tunnels have emergency doors that can close if needed. * Sturdy building construction can withstand reasonable blasts. * Retractable buildings provide full nuclear-bunker level protection. If the ability to retract exists, this might also be used during the winter, nighttime, etc, just for climate control. > > Round edges and 2-3 km in height so inside flight is possible > > > Inside flight implies that the smog idea either won't work, or will require flying by instrument. Shouldn't be a problem at this level of tech. Also requires friend-of-foe identification, again not an issue. All these layers of protection would give you a super-well-defended city, but I suspect would be too much of an urban redesign. But some of them might be usable to beef up the defenses you take from other ideas, at least. [Answer] I think the force field should be invincible and can be only activated only in times of war.my idea as an electrical engineer you can make a complete full circuit that half of the dome is a terminal and the other half of the dome another terminal that ends the circuit circle, when activated each terminal connects together,completing this force field circuit and form this force field that is highly strong and can defect anything ]
[Question] [ Something I've pondered in a work of mine, in which a corrupt authority figure threatens the protagonists with being sentenced to forced labour "chiseling ice off of (insert name here) comet." Assuming they really are masses of ice as scientists now believe, could a comet be large and stable enough to hold a prison colony? [Answer] **It's possible** Sending forced-laborers to a comet-colony might be more trouble than its worth, since it'd be easier to just send autonomous probes like [Kuck's Mosquito](http://nick-stevens.com/2015/12/15/kucks-mosquito/), but if the specific aim of the corrupt ruler is to punish people then i think he might ignore the practicalities. And i think with enough workers in the same spot, he might just break even for costs and expenses. Living on the surface of, or even *inside* an asteroid is a thing that people have been seriously considering for quite some time, since asteroids are very resource-rich and often large enough to support structures on them. Since comets aren't 100% ice anyways, i'd imagine it wouldn't be much more difficult to build on, or inside of them, compared to an asteroid. [![enter image description here](https://i.stack.imgur.com/yRg4X.jpg)](https://i.stack.imgur.com/yRg4X.jpg) It doesn't have to be flashy of course, especially for a penal-colony, but it's a neat idea. [Answer] ## Could a comet be large and stable enough to hold a prison colony? Comets can get quite large. [Comet Bernardinelli-Bernstein](https://science.nasa.gov/missions/hubble/hubble-confirms-largest-comet-nucleus-ever-seen/) for example, which is larger than the state of Rhode Island. Though their gravities are meager milligees. A prisoner could achieve escape velocity by jumping. As for stability. When comets swing through perihelion, at closest approach to the Sun, things get a little messy as surface volatiles (water, carbon dioxide, methane) and dust get blown off. But comets usually have highly eccentric orbits and spend decades or centuries out in the cold fringes of deep space where nothing happens. If you've got competent specialists overseeing the operation, hacking off, transporting, and processing chunks of ice isn't inherently dangerous to the comet's stability. Same goes for building a station near or inside the comet, with competent engineers. Building inside the comet may be preferable because it offers extra protection from cosmic rays and general space radiation. And there's no prison like one trapped under a mile of ice. [Answer] **Depends on the style of prison** * You could quite reasonably have a setting where comets (or asteroids) are mined for water ice and other elements. Say the [lunar water](https://en.wikipedia.org/wiki/Lunar_water) turns out difficult to exploit, then it **may** be [more economical](https://www.projectrho.com/public_html/rocket/appmissiontable.php) to get water from a near-earth object than from the surface of the Earth. * Fuel and time to transport people will be a major obstacle in any realistic, near-future setting. If the choice is sending 100 highly-paid workers, or 100 unpaid prisoners plus 10 highly-paid guards, the cost of sending extra guards will surely outbalance any savings from unpaid labor. Moving the prisoners will be a significant drain on the public purse. *(But that is the case in many Western societies. Even if prisoners are made to work, the prison system runs a net deficit as far as money goes. Privatized prisons may profit still yield a profit, but* not just *from exploiting prison labor. And society may or may not benefit from incarcerating rule-breakers.)* * The prisoners will have to work in a high-tech environment. Any one of them is likely able to kill dozens by *just not being careful*, let alone actual malice. A chain gang is right out. [Answer] # Comets Bad To get even close to the realm of plausibility, there needs to be an already-established prison on a celestial body. Comets are terrible for this, because they have very eccentric orbits and spend decades/centuries away from earth, and would be exponentially more expensive to supply and maintain. # Asteroids Better You should aim to have your prison on either a moon or asteroid. I suggest [Ceres](https://en.wikipedia.org/wiki/Ceres_(dwarf_planet)). It's an asteroid so big we call it a dwarf planet, the only one inside of Neptune's orbit. It's big- about [the size of Texas](https://www.reddit.com/r/space/comments/2y5f0o/heres_the_size_of_ceres_compared_with_texas_pluto/), comprising 40% of the entire asteroid belt's mass. It is rich in water (ice) and oxygen, which that make it easier/cheaper to maintain a long-term presence. The low escape velocity makes it easy to launch ([or throw](https://www.youtube.com/watch?v=csFyhYSLwic)) cargo ships of mined minerals to Mars or Earth to *slightly* offset the **ENORMOUS** cost of maintaining a life-sustaining ecosystem on a rock in outer space. [Answer] ## Comets are a poor choice for long term settlement The idea of if a comet can be economically mined is simply a matter of available technology. For a civilization where adequately advanced propulsion exists, to make the journey relatively quick and affordable, then the answer is of course yes. But the bigger question is if one would make a permanent penial camp on one. The thing about comets is that they experience everything from the cryogenically cold temperatures of the Oord cloud to the sizzling radiation and solar winds of passing close to the sun. Plus they are extremely unstable. A bunker you bury 50m under the surface of the comet one year, may the next year be exposed and fly off into space or be crushed by glacial forces of the shifting ice. This means that no matter what other assumptions you make about the civilizations tech level, that you automatically know that the life support requirements for this facility will be much more complex than any facility you could construct on an astral body that follows a less elliptical orbit. ### ... but that does not rule out mining comets completely That said, there is nothing stopping comet mining from being a perfectly valid punishment for prisoners, as long as you rule out the part where it is a permanent prison facility. One of the problems with getting water in space is that nearly all of it is either at the bottom of a powerful gravity well like Earth, it is just a trace molecule that you can only get by melting the stone that contains it like on Luna or it is frozen as hard as rock like on Europa making it very difficult to mine in a low gravity environment. Comets present a unique opportunity because they are not solid balls of ice, but rather more like snowballs. This should make actually gathering the ice much easier, especially if you time your mission just right for when the ice begins to melt, but before it begins to violently boil off. So, you could have prison ships that go to a comet perform the comparatively dangerous but economically more efficient task of mining it, and then come back. As for "chiseling ice off of Biela’s Comet.", this phrase could still hold, even if the average person has never heard of Biela’s Comet. It makes since for a Judge or prosecutor to know exactly what comet will the next penal mission will be to, because it is a normal part of sentencing, and the prisoner does not need to know what Biela’s Comet is to know that he is being threatened with a comet mining mission. ### Can unskilled labor compete with robotic automation and professional mining crews? Technically no, but they don't have to. One of the biggest assumptions about penial colonies is that you can only work with people with negligible practical skills, but modern prison labor is more and more often being paired with rehabilitation and education programs. Many Western European prison systems show that if you teach a prisoner a valuable skill, that they are more likely to take pride in thier future and are less likely to re-offend once released. So instead of just putting a pickaxe in these prisoner's hands on day 1, you force them to study what ever technical and mechanical skills they need during the several months long journey to the comet they are sent too. In this time, they either learn the skills they need to make it a successful mission, or they don't and they get themselves killed. So the threat of "chiseling ice off of (insert name here) comet.", more accurately means you are being threatened with 16 hour shifts in front of a computer screen watching tutorials and lectures cramming in the equivalent of an entire technical college's education that your life literally depends on. And once you get there, you are still faced with around the clock geology surveys, maintenance tasks, rationing, etc... all while sitting in an barge built by lowest bidder government contracts floating near the tail of comet that could at any point be ripped through by an un-detected chunk of ice. The barge itself could use an auto navigation system that will only activate for a return mission once the water tanks are full or the mission takes so long that the risk of losing the ship outweighs the benefit of topping off. Any crew that fails to educate itself will typically fail to top off and face being resentenced for another mission. Those who educate themselves well can top off before the comet starts to come apart reducing the chance of dieing during the mission, and then re-enter society with a valuable education that could be applied to a wide range of less dangerous jobs that rely on the same general skill set. In other words, it does not need to be hard labor to still be a very meaningful threat. [Answer] Not precisely, but you don't have to be precise. Comets aren't like asteroids in a lot of ways, but the biggest one is that they aren't a single, big chunk of rock. Even most asteroids are dusty conglomerates, but comets are like pop-rocks, waiting to heat up to the point that the melting ice allows them to release their gasses. Imagine trying to build an underground bunker in a shelf of natural gas shale. How long do you think it could survive? More importantly, what would be the value of that mining colony when the comet itself is exhausted of material? With a comet, I can't imagine that it would be a good idea to be drilling into the substrate that your habitat is anchored in. A better idea would be to build a prison ship that *visits* comets and cracks pieces off of them. Despite how the Expanse starts, you don't need a ship to actually haul spacebergs from one place to another, you just need a tug to get them going in the right direction, and patrols to make sure that opportunists aren't shaving their share off of them on the way. ]
[Question] [ I have a species of sapient humanoids in my world capable of flight using 24 foot wide wings. The world's being used for a science-fantasy world, so I'd like some realism, but some can be handwaved. Not all of it, though. However, I don't know if it'd be necessary/enough for my world. Here's my world's parameters: 1. 75% Earth gravity 2. 2x Earth's Diameter (Don't worry about the difference in diameter vs. gravity) 3. 3 times Earth's atmospheric pressure (Venus has 92 times Earth's gravity and likely isn't much lower in gravity, I think 0.75g and 3x atmospheric pressure is fine). 4. 36% atmospheric oxygen. My species: 1. Is mammalian/avian(Both mixed) in nature, with some dinosaurian traits thrown in; They have feathers and hair and give birth to live young, which they breastfeed; Are warm-blooded; But have long tails like a reptile's. 2. Is about 7'6" on average as an adult, going down to 6'0" to 9'0". 3. Weigh about 180-240 pounds, up to 360 (Taller individuals) and down to 160 pounds (Shorter individuals)(These are using Earth Gravity, it's more like 120 lb to 270 lb). 4. Have 24 foot wingspans, 5. Their wings are bony, with two of their wing's fingers holding up the wing's end, and the other two are bound with the wing membrane (Different in structure to their body skin) to form an alula-like structure of the two fingers. The whole wing is bound with a similar membrane (Which is much thicker and stronger than their bodily skin) from to sides of the body to the wing finger tips on the trailing edge, with additional membrane running on the top, stopping at the alula. The alula fingers are bound together but other wise free, and are fully moveable like its counterpart in birds, and the wing fingers are similarly bound together (But still attached to the wing). 6. Are obligate carnivores, but began agriculture as a way to keep prey in one area year-round, and do eat some plant material (Their overall diet is doglike; They need meat, but some plant matter for supplemental nutrition is helpful). 7. Evolved from a species of flying predator that mostly hunts on the ground (Like a secretary bird), so flight would be mostly for travelling, not high-speed stunts/hunting in thick forests (Although they can do this, it takes practice, like gymnastics), with travel speeds being about 48 miles per hour at a normal pace (Their cruising speed, if you will). Other biological traits include: 1. A highly mobile (But not prehensile) lizard-like tail with a large vane at the tip for communication; 2. A large tail fan near the top of the tail, used for a fair amount of steering in flight; 3. Three-toed digitigrade legs, with hooves on the toes (Like some early horses); 4 Six-fingered hands (Held at the side while flying unless holding something, in which case a streamlined holding method is used); 4. And great color vision, hearing, and olfactory senses (On par with hawks, cats, and non scent-bred dogs, respectively). 5. Their distant ancestor is a six-finned placoderm counterpart that eventually evolved onto land with six limbs. 6. They also have 6 pairs of tendrils used for various uses: 2 pairs of breathing/scent collection tendrils for breathing and scent aid; 1 pair for taste and drink absorption (Think a butterfly's proboscis) They should be able to fly with an extra two-thirds of their weight, like other flying animals. **Is my species able fly with 24 foot wings, or is it too small/big for my world? If it's too small/big, what's the minimum wingspan?** [Answer] I'm going to say that your creature can actually fly very easily, given your world's conditions. 180-240 pounds for average weight gives a mass of about 81-108 kilograms (metric is much easier to work with, and mass figures don't change when gravity does). A 24-foot wingspan translates to about 7.2 metres. I'll note that your height figures might need to change (I'd advise about 2.5 metres as your low end: my rule of thumb is that each metre in wingspan translates to a minimum of one foot in height/body length), since the wings need to be able to fold up against the body effectively, and they can't do that if the folded wing is still taller than the rest of the body. As noted by KerrAvon in his answer, [Quetzalcoaltus](https://en.wikipedia.org/wiki/Quetzalcoatlus) is our best practical comparison point for big flying creatures and their feasibility. Its mass is still debated, but current estimates are around 200kg, with a wingspan of 10-11 metres. Half that mass with two-thirds the wingspan looks eminently plausible to me (albeit your top end of 360 pounds or 162 kilograms is probably an excessive size range to have), so **your creature could probably fly on Earth without much difficulty**. With your world, you've specified a lower gravitational pull. This helps with flight for the obvious reason that less lift is required to stay aloft. However, you've also specified that air pressure is tripled at sea level compared to Earth, which is a mixed bag. On the one hand, higher air pressure means that each beat of the wings has more air to "push" against, allowing more force to be applied; it thus takes less wing surface to provide the same lift, as long as muscle strength is equal to the task. On the other hand, it means more air resistance acting against you (drag) and more energy being required to beat the wings: both of these can be overcome with sufficient strength, but this is likely to shorten practical flight range due to exhaustion. Short flights will be easy enough, but flying for extended periods will be much more draining than on Earth. **Verdict**: the endurance of your creatures in the air is questionable, but they could fly even on Earth: on your world, it will be very easy indeed. **Postscript**: Your fliers having both arms and legs as well as wings means a lot of drag for dubious (pre-intelligence) use, and evolution is especially ruthless about energy/mass efficiency when it comes to flying creatures. It's not impossible to have usable arms and legs, but their strength is questionable. The arms in particular won't have much muscle (wings take so much that there just isn't much room in the chest area to support separate arms). As for the legs, you'll need to figure out if your creatures are more avian or mammalian in build; feathered wings imply an avian build, but you could potentially tinker with their wing structure. Avians have to be able to launch themselves with their legs, since their wings can't contribute until they get far enough off the ground; the wingtip feathers would bend on contact with the ground rather than provide useful propulsion. This, obviously, requires strong legs, which will raise your mass estimates for your fliers. It also means that your creatures can be practical bipeds, however, as their wings will only be necessary for flight. If your creatures are built more like pterosaurs (your creatures can't be built like bats unless you eliminate the arms, as a bat's wing membrane runs from the shoulders to the hips and beyond), their wings can be used to impart practical contact force with solid objects, as the wing membrane has muscle and bone to support the edges and prevent it from deforming. Their wings would thus be their forelegs (they would walk with wings folded, probably on their wrists or the equivalent joint) as well as the main force involved in launching. In this case, the legs would likely be incapable of supporting their full weight for more than a few seconds, because they would walk on four limbs: the rear legs simply wouldn't need that much muscle, being more for balance than for taking their full weight. [Answer] **Wingspan is OK, but...** The standard fallback comparison for "is my big flying creature plausible" questions is to look at [Quetzalcoatlus](https://en.wikipedia.org/wiki/Quetzalcoatlus). This is slightly problematic, since there is a lack of certainty about how much it weighed (translation: everyone is making educated guesses) but it does provide a baseline. In comparison to this baseline, your creature looks plausible, especially on a world with significantly less surface gravity than Earth. However, there are some minor nitpicks, and one major problem with your world. First, the minor nitpicks. While you want your flying creature to have a low mass, for obvious reasons, it seems a bit *too* low for a creature that is so large and has so many "extras" - fully functional arms, fully functional legs, a head large enough for a sapient brain and all sensory equipment at better-than-human levels (which requires more brain for processing the inputs). Even with bird-like hollow bones, it still seems to me that it should mass a bit more. Additionally, the airborne cruising speed may be a bit high for a creature operating in such thick air (3x Earth sea-level density), though I could be mistaken on this. Second, the big problem is the oxygen content. As noted in [this question](https://worldbuilding.stackexchange.com/questions/146903/whats-the-useful-range-of-atmospheric-oxygen-content-for-fire), as soon as the oxygen percentage goes above 35% any fire that starts will not stop until there's nothing left to burn. This is an undesirable quality in an inhabitable world. (It also makes iron tools rust if you so much as glance sideways at them, but that will only worry you if you survive the inferno long enough to reach the Iron Age.) I definitely suggest you reduce the oxygen percentage by at least 3 points. Other than that, I would consider it plausible if I were reading a story with these creatures. Good luck with the worldbuilding! ]
[Question] [ Earth is our only example of a habitable planet. The surface of Earth is 29% land and 71% ocean. I am wondering what other land ratios can create a habitable planet. Half a billion years ago, Earth had little land and was covered in ocean. Yet, even back then Earth had life. So it is definitely possible for a habitable planet to have a surface that is 100% ocean and 0% land. I'm not sure if it is possible to have a life-bearing planet that is 100% land and 0% ocean though. What is the maximum amount of land (ratio-wise) that a natural planet can have that humans can still live on? Assume the mass, volume, and distance from a main sequence star is the same as Earth. [Answer] Best estimates say a world can be habitable (for a sufficiently broad definition of habitable) within the range of 75% land to 15% land. That is just to have stable gas ranges and enough humidity to have consistent rain to keep the ocean supplied with minerals. Note though that at higher land areas the amount of the land that is habitable is fairly small. And said planet will not remain habitable indefinity. Tectonics seems to matter more than total water content. It is also worth mentioning that if the ocean is only in one hemisphere the other hemisphere will be too dry to be habitable. [Source](https://arxiv.org/abs/2211.09473) [Source 2](https://www.hou.usra.edu/meetings/habitableworlds2017/pdf/4027.pdf) [Answer] If what you mean by "ocean" is a large body of surface-level water, then a planet can theoretically have 100% land while being able to host life. If you are talking about no water, a planet cannot harbor life as we know it. Now let's talk about the theoretical "no water" planet since it is easier to explain. (Note in this answer I will be talking about "life as we know it," not "life as we don't know it") Organisms on Earth need water because of it's molecular structure, according to [this article](https://sitn.hms.harvard.edu/uncategorized/2019/biological-roles-of-water-why-is-water-necessary-for-life/) Single celled organisms simply would not survive without water. A lot of cells have something called a phospholipid bilayer, which are lipid molecules (fat) arranged in a unique pattern where the polar "heads" face outwards while the nonpolar tails face inwards. This is because of water's unique polarity, which allows the heads to face outwards towards the water. If a cell or microorganism had little to no water, it would shrivel because of the absence of water inside the cell. When this happens, the bilayer begins to fall apart, and the cell dies. In contrast, a planet with no surface water *might* be able to host life, but it will be unlikely. First of all, many scientists theorize that life/the chemicals needed for life came from asteroids. If they did, cells or single celled organisms would have needed water to be able to arrange themselves together. If there was a surface-level ocean that got baked by a solar flare, well, tough luck. The reason why I say that life could be likely is because of [geothermal vents](https://en.wikipedia.org/wiki/Hydrothermal_vent). [The first known life forms on eart](https://en.wikipedia.org/wiki/Earliest_known_life_forms)h were chemosynthesizers living around geothermal vents. If your world has a large underwater ocean or even a small aquafer, all it takes is some geothermal activity and a lot of luck. [Answer] No oceans would be fine, but life like ours cannot evolve without a lot of of water in some form. Even in your percentages, we have lakes, ponds, creeks, rivers, rainfall, snowfall, even moist mists, that some desert insects and plants can collect and thrive upon. Without any water, there would be no plants or biology as we know it. That said, the entire planet can be like the interior of the Americas, land with a weather system. Lakes, rivers, aquifers (underground lakes). And we have the full spectrum of climates, from desert to rainforest. No reason your planet cannot be like that. As long as water is available in some form. Yes, much of the rain is evaporated from the oceans. It doesn't have to be that plentiful, and probably would not be, coming from lakes and rivers. It just has to be available. Like modern desert life (both plants and animals) life would evolve mechanisms from the start to get by on less water and to internally store more water. I'd focus my story research on desert life. [Answer] It may be possible with special chemistry of the planet's crust. It is rich in hygroscopic minerals that can absorb many times their weight in water while still solid. Many such compounds exist in nature, such as containing calcium and magnesium. Life could evolve to extract necessary water out of these and humans are able to do it too simply by heating the rocks. However some care needs to be taken, they are irritating and caustic to humans. [Answer] In addition to Juraj's answer, it would also be possible for there to be no open water on the planet but abundant sub-surface water, with puddles existing for a short-ish time and then are absorbed into the ground. Think of a beach where when it rains the sand gets wet, but never actually creates a puddle. The water could also still be easily illuminated depending on the structure of the "sand" (e.g. Star Trek TNG; The episode with the silicon based life form that formed at the border of the light and dark while being underground). So your question potentially becomes: Can humans live on a planet without open water? [Answer] 100%. Not entire surface will be perfect for life, but the same is true for Earth. We have Sahara mostly surrounded by water. Life exists in Sahara. Some people mention that oceans necessary for life development. Well, life exists on Earth for ~3.42 billion years. It is plenty of time for planet to lose significant part of water. So, even if "habitable" somehow means "good enough for humans to evolve", the answer is the same. 100%. ]
[Question] [ I want to do something interesting with Caleb Scharf’s speculation that hyper-advanced aliens could make themselves immortal by uploading themselves into the cosmic background radiation. These light creatures also quantum entangle their component photons to help with error control. One problem is to figure out how their time perception would work. Since the aliens component particles moves as fast as light, wouldn’t some relativistic law mess with how they experience time? [Answer] Your question is pointless. There can't be photon based intelligence. As stated [here](https://physics.stackexchange.com/a/65053): > > As a young student, Einstein tried to imagine what an electromagnetic wave would look like from the point of view of a motorcyclist riding alongside it. But we now know, thanks to Einstein himself, that it really doesn't make sense to talk about such observers. [...] > > > One of the most basic geometrical ideas is intersection. In relativity, we expect that even if different observers disagree about many things, they agree about intersections of world-lines. Either the particles collided or they didn't. The arrow either hit the bull's-eye or it didn't. So although general relativity is far more permissive than Newtonian mechanics about changes of coordinates, there is a restriction that they should be smooth, one-to-one functions. If there was something like a Lorentz transformation for v=c, it wouldn't be one-to-one, so it wouldn't be mathematically compatible with the structure of relativity. (An easy way to see that it can't be one-to-one is that the length contraction would reduce a finite distance to a point.) > > > What if a system of interacting, massless particles was conscious, and could make observations? The argument given in the preceding paragraph proves that this isn't possible, but let's be more explicit. There are two possibilities. The velocity V of the system's center of mass either moves at c, or it doesn't. If V=c, then all the particles are moving along parallel lines, and therefore they aren't interacting, can't perform computations, and can't be conscious. (This is also consistent with the fact that the proper time s of a particle moving at c is constant, ds=0.) If V is less than c, then the observer's frame of reference isn't moving at c. Either way, we don't get an observer moving at c. > > > [Answer] **Insofar as we know, photons don't experience time** And this could be an uber-cool aspect of your world. According to relativity — and from the frame reference of the photon — photons *instantly* arrive at their destination. *They experience no lifespan.* Why? Because according to relativity, once you're traveling at the speed of light, time stops. **But your lifeforms don't necessarily have a destination!** Photons, for example, are emitted from a star, travel through the universe, then hit something. From the perspective of that something, that photon may have traveled for 13 billion years to finally cause skin cancer on some poor sucker who just wanted a day at the beach. But your lifeforms *aren't doing that.* They're moving around the universe. They may have had a beginning (an "organization" of photons into a coherent and conscious being), but they don't have an end... *so long as they don't hit anything.* **And that could be an interesting part of your world, too...** Outer space is whomping empty,*<citation needed>* but it's not empty. There's dust and molecules and atoms floating all over out there. To us it's empty. But to your photonic lifeforms, all that stuff is hazardous to their health! Once a photon impacts with atomic matter, its energy is transferred to that matter and the photon ceases to exist.1 *That's really unhealthy for your photonic lifeforms.* But it's really good for you, because it gives you something you can use to create a crisis-solution device in your worldbuilding or storybuilding. **But let's get back to that stopped time issue** The real question here is, would photonic lifeforms ever notice life such as found here on Earth? *Can they notice it?* For them all time is stopped. A photon circling a meter-diameter holding pattern over the Earth is still moving at the speed of light. Maybe it sat there doing that for fifty years... but the photon experienced *nothing.* From the moment it started circling to the moment it hit some feral oxygen atom, it experienced no time. Which means that interacting with the rest of the universe is a bit of a problem. --- 1 *That's a simplified statement. Depending on the nature of the object the photon strikes, a number of things can happen. But for the sake of this answer, the simple statement is sufficient.* [Answer] ## Photonic life is impossible before you even introduced general relativity to your question Life as we know it is formed from particles bound into fixed structures created by electromagnetic forces. You can not make life (or any sort of machine for that matter) out of anything that has no structure. Photons which have no mass, attraction, or repulsion with one another represent one of the least structured subatomic particles you can imagine. To try to understand this idea better. Imagine you are given a tank full of water, and told to make a car out of it... you will find that liquid water is utterly and completely incapable of being formed into wheels, doors, framing, etc. by virtue of the fact that it lacks structure... photons have far less structure than water, and is thus that much more impossible to make life out of. ## But that does not stop you from making an organism that APPEARS to be nothing but light While photons themselves can not be alive both for structural reasons and for time dilatation reasons as other answers have suggested, you can add some kind of [Minovsky Particles](https://tvtropes.org/pmwiki/pmwiki.php/Main/MinovskyPhysics) to your setting for creating an organism out of some material that meets the physical properties you want without all the annoying limitations of real world physics. Or perhaps your could consider some variation of [Destructive Teleportation](https://tvtropes.org/pmwiki/pmwiki.php/Main/DestructiveTeleportation) as a sort of version of what you are asking about. **Some possible solutions include:** **OPTION A:** Add a new kind of Electron/Proton like set that does not interact with normal matter, but can still emit photons like normal matter. In this case you would have intangible beings that would APPEAR to be made out of nothing but photons, because that is the only aspect of them we could interact with, but they would in fact be made out of this alternative form of matter that does not move any faster than normal matter. In this case time dilation would be a non-issue. **OPTION B:** Add a new kind of subatomic particle that is massless like Photons, but has structure giving properties like the electromagnetic forces found in electrons and protons giving your beings both form and the true speed of light. In this case you could have a being that has the physical form of a living being, but is in every other way made out of particles which can best be described as photon like. In normal matter, electrons orbit the nucleolus at about 2200km/sec... no where near the speed of light, but still pretty impressive speeds. That said, time dilation calculations don't really care how fast things are bobbing and weaving at a subatomic scale, they only care about how fast you move compared to other objects through space. This means you could have a massless lepton orbiting a massless baryon at the true speed of light, but still be on average sitting still compared to its reference frame. So in this since, you could be made out of something like photons and still experience normal time. That said, if this massless alien where accelerated towards the speed of light compared to a reference frame, it would experience time dilation just like normal matter would. **OPTION C:** Light as a medium for data. While you can not actually exist as a living being made out of photons, light is capable of being encoded with information. So, if you want to relax you definition from "a living being" to "the instructions for creating a living being", then you might have some wiggle room with real for true photons. If you consider the possibility that everything about a person could be encoded and shot off into space by a laser, that signal could in theory eventually be used to reconstruct that person. They would not only not experience time while traveling as a beam of photons, they would literally not be themselves at all, only a data representation of who they are. While this form of immortality may seem useless, it is not that unlike the idea of cryostasis. If your aliens want to live forever, but can't because they have not solved immortality yet, the old and dying may opt to be preserved as a sort of transporter signal shot through the dead of space hoping some time in the distant future someone can show up with an FTL ship, pick up thier signal and reconstruct them... or something of that nature. [Answer] Perception requires intelligence, intelligence requires a thought-process, and a thought-process requires a "brain" that implements it, and a brain consists of particles that exchange information between each other to come to logical conclusions and make decisions. These "particles" are neurons in a human brain, transistors in a computer or photons in the case of your photonic aliens. You wrote that "These light creatures also quantum entangle their component photons to help with error control". Is that the medium that is used to exchange information between the photons that make up their "uploaded brain" in the cosmic background radiation? If so, remember that information can't travel instantly (not unless you invent a hypothetical physical effect that allows it). That means their though processes would be limited by how fast their quantum-entangled light particles can exchange information, which would mean that this thought-process would experience time. Does a thought-process imply consciousness? That's a question for a philosopher to think about. ]
[Question] [ Since our ears have small hair inside which (at least partially) make it possible to hear, is it possible for an animal to have hearing based on hair on its whole body? Like highly specialized small hair used to hear, but rather than localized, spread out on the body? [Answer] Flies and other invertebrates posses already this [capability](https://en.wikipedia.org/wiki/Trichobothria): the little hairs they have on their bodies allow them to perceive pressure waves and react to them. > > Trichobothria (singular trichobothrium) are elongate setae ("hairs") present in arachnids, various orders of insects, and myriapods that function in the detection of airborne vibrations and currents, and electrical charge. In 1883, Friedrich Dahl observed that they were deflected by the sound waves from a violin and labelled them 'hearing hairs'. > > > That's why try catching a fly with your hand is difficult: the pressure waves produced by your moving hand warn the fly of where you trying to strike from. ]
[Question] [ I'm writing a SF military novel and at some point lieutenant takes command of forces because his own captain went crazy. The captain still gives lawful orders but he's only taking things from his own imagination into an account despite the situation in real world indicates none of that is going to happen and requires completely different set of actions and everybody knows that. Can a lieutenant legally override chain of command to save the situation? Or it's always an act of insubordination because captain's orders are still lawful according to military law? [Answer] In a perfect world, the lieutenant would inform a major or lieutenant colonel who is the superior of the captain, or possibly a medical officer attached to the unit, that the captain is *obviously* out of his mind (medically unfit to command). It does not matter so much that the orders would be legal if the situation was as the captain sees it, the problem is that the captain is delusional. A lieutenant who takes that decision into his or her own hands is risking trouble, both if the diagnosis is correct and if the diagnosis is wrong, because militaries don't want *junior* officers questioning the sanity and situational awareness of their *seniors* all the time. Yet if communication is obviously impossible, the subordinate may act. In a science-fictional setting, we might be back to situations where the communications lag is measured in years, not seconds. See section 1088 of this [US Navy Regulation](https://www.marines.mil/Portals/1/Publications/United%20States%20Navy%20Regulations.pdf). > > 1. It is conceivable that most unusual and extraordinary circumstances may arise in which the relief from duty of a commanding officer by a subordinate becomes necessary, either by placing the commanding officer under arrest or on the sick list. Such action shall never be taken without the approval of the Commandant of the Marine Corps or the Chief of Naval Personnel, as appropriate, or the senior officer present, except when reference to such higher authority is undoubtedly impracticable because of the delay involved or for other clearly obvious reasons. In any event, a complete report of the matter shall be made to the Commandant of the Marine Corps or the Chief of Naval Personnel, as appropriate, and the senior officer present, setting forth all facts in the case and the reasons for the action or recommendation, with particular regard to the degree of urgency involved. > 2. In order that a subordinate officer, acting upon his, or her own initiative, may be vindicated for relieving a commanding officer from duty, the situation must be obvious and clear, and must admit of the single conclusion that the retention of command by such commanding officer will seriously and irretrievably prejudice the public interests. The subordinate officer so acting > > > a. Must be next in succession to command. > > > b. Must be unable tn refer the matter to a common superior for the reasons set forth in the preceding paragraph. > > > c. Must be certain that the prejudicial actions of the commanding officer are not caused by instructions unknown to him or her. > > > d. Must have given the matter much careful consideration, and have made such exhaustive investigation of all the circumstances as maybe practicable. > > > e. Must be thoroughly convinced that the conclusion to relieve the commanding officer is one which a reasonable, prudent and experienced officer would regard as a necessary consequence from the facts thus determined to exist. > > > --- Regarding the comment by Uvphoton, the captain may well be aware of orders or circumstances which the lieutenant has no need to know. Say the company is part of a *deception*, the troops are supposed to act *as if* they were the spearhead of a larger force, yet no such force exists. The senior would appear to be acting on a wildly unreal situation assessment. [Answer] # The second in command needs to have clear and unambiguous evidence. The second in command can in many military branches remove their superior, but they need to meet several criteria. 1. Retention of the commander must massively impair public interests. If they're a bit kooky on a routine patrol you can just screen their orders and manage them till you get back in contact with superiors. If they're going insane in a combat zone, then you need to manage them. 2. You must be unable to contact superior officers. You're supposed to relieve them by contacting senior people. You must have tried and failed to do this. 3. You must ensure their behaviour is not caused by secret orders. Maybe they are ordering a dangerous plan of action because they have been ordered by the admiralty? 4. You must exhaustively prove that this matter is well investigated. Can you do a drug test? Can you scan the captain for brain damage? Have they done anything that is wildly inappropriate like pissing themselves on the bridge? If you can prove all these factors, you can relieve your superior. Initiative is prized in the military, but also they don't want subordinates just taking out superiors because they don't like legal orders. If you get the doctor and other officers to agree this is a necessary and obvious need, you'll probably be ok. [Answer] Captain and lieutenant are both Army ranks and Naval ranks, and unfortunately they have vastly different meanings between the Army and the Navy. * In the Army, captains and lieutenants are [subordinate officers](https://en.wikipedia.org/wiki/Subordinate_officer). They are never ever **ever** supposed to question their orders: > > *"Forward, the Light Brigade!" Was there a man dismay'd? Not tho' **the soldier knew some one had blunder'd**: theirs not to make reply, theirs not to reason why, theirs but to do and die: into the valley of Death rode the six hundred.* ("[The Charge of the Light Brigade](https://en.wikipedia.org/wiki/The_Charge_of_the_Light_Brigade_(poem))", by Alfred, Lord Tennyson, 1854.) > > > An Army lieutenant who attempted to take over the command of his superior officer in time of war would be summarily shot for insurbordination in the presence of the enemy, and rightly so. *"Theirs not to reason why, theirs but to do and die."* Army lieutenants and captains are not privy to the big picture and cannot judge to reasons why their orders were given. The higher command may even have deliberately given them orders knowing full well that they will die trying to fulfill them; it happens: sometimes the higher command has to sacrifice some low-level units in order to achieve greater goals. The only imaginable situation when a lieutenant takes over the command of his immediate superior and doesn't get shot or hanged is if the company (commanded by the captain) was some sort of commando force operating autonomously on short-term mission in enemy territory. But commanders of commando forces are generally very experienced soldiers, fully screened and vetted, and do not tend to go mad overnight. * In the Navy, a captain is a senior rank, equivalent to an Army colonel. If the captain's ship was operating autonomously on some sort of long cruise, and if during this cruise the captain become unable to discharge his duties, it may be the case that his second in command (and nobody else) may be justified in taking over the command of the ship. It may even be his duty to do so, if the captains orders put the ship in immediate danger -- navies have this quaint notion that the ship is more important than the crew, and definitely more important than the niceties of protocol. When they return home, there **will** be a Court Martial. The officer who relieved his captain of command will have to explain himself, and bring proof that his actions were justified and necessary. But, at least, the Navy officer has a fair chance to escape unshot and unhanged, unlike the poor Army lieutenant. ]
[Question] [ I am envisioning an Earth that has been stripped of natural resources. Clean water, food, and wood/trees are rare and costly enough to be used as units of exchange. Whole swaths of land once fertile are desert or perpetual dust bowls (i.e. the great plains,etc.) Wind power is very common and coal is still available. Oil and Natural gas are used up or so rare they are novelty. Dust, sand, and grit are so airborne that sunlight is reduced in most areas, making crops hard to grow and harvests very reduced. Solar power is not very effective I would think but maybe wrong. Ocean levels would they be higher or lower? Land line phones and telegraphs are available, some radio transmissions are available as well but limited by the atmospheric conditions. I would like to envision a types of dirigibles or zeppelins with some type of rudimentary motor running props to propel them as they only real air travel. steamboats and trains I would assume to be available also. I am assuming that food and water shortages decimated much of the apocalypse surviving population as well. Other then Eco disasters and nuclear winters what other scenarios could set society back like this.I could see possibly nuclear power plants still being around but I would love to see them removed or greatly reduced in effectiveness by the scenario. [Answer] # [Solar Flares](https://en.wikipedia.org/wiki/Carrington_Event): The sun goes through an extended period of massive solar flares. Massive EMP dumps from the sun cause even telegraph lines to catch on fire. Computers are simply irrelevant as they are destroyed soon after being taken out of Faraday cages. Power generation in general becomes extremely problematic and power grids all collapse. Further, the levels of direct radiation skyrocket. Organisms are damaged and killed, and the increased output may cause global warming to spike. Communication stops. Shipping stops. without a supply chain or computers, factories stop. Finance stops. There should still be some natural gas production, since you'll want to supply your dirigibles with helium (a by-product of natural gas production). Otherwise, electrical discharges could cause hydrogen tanks on dirigibles to explode as they come and go. Many lighter than air gasses are explosive or highly toxic. But airplanes would be problematic to fly as the electrical systems short out. Engine efficiency plummets due to the lack of electrical systems, and only a few military aircraft can afford to fly with the non-electrical systems and EMP shielding they need. Cars would need to be very old-fashioned if you could even get the fuel to keep them running since nothing is being shipped. [Answer] Since you are still talking about an electrical society with the possibility of solar power (just diminished, in your description), phone lines and telegraph still work, wind power works, "steam" power seems highly unlikely. So does coal. In such a hazy environment, respiratory health would be at a premium, and greater pollution by coal would be outlawed, either by the government or by vigilante destruction. Solar power might be diminished, but not useless; just make the collectors larger, there is presumably enough sunlight reaching the surface to keep it warm, and I doubt particulate haze will rise above the mountains. After asteroid strike 65 million years ago that killed off the dinosaurs,the world was only in darkness [for about two years](https://www.livescience.com/60217-dino-killing-asteroid-caused-two-years-of-darkness.html), all the particles settled out of the atmosphere and the skies became clear. Heck, give it three more years, and the air is crystal clear. Wind pushes air against obstacles and knocks particles out of the sky. And Wind can carry particles from deserts thousands of miles, but eventually the wind stops and the particles fall down. And the biggest factor in air cleaning is **rain**, even tiny particles are struck by raindrops, absorbed and fall to the ground. Rainy places have clean air, it is literally getting washed frequently. And those places are usually good places to grow crops. Or rainforests, nature's spontaneous "farmlands". As long as there is heat, there is evaporation and wind, and the more of those there is, the more rain and air cleaning there will be, somewhere. But then **wind** again, causing air mixing, so the clean air blows out, dirty air blows in, and gets washed by more rain. Save a few special dead spots caused by mountains creating weird circulatory patterns, most places in the world end up with clean air. This is why the skies after the asteroid cleared in just two years. Two more after that and the effect is amplified. The only way your world is possible is if the particulate pollution is constantly being replenished on a massive scale. Since it is constantly being washed, you must invent a scenario in which it is constantly being dirtied. I don't know what that is, perhaps a chain of volcanoes that is constantly spewing particulates into the atmosphere, for decades on end. Here is a map of the [world's major fault lines](https://www.mapsofworld.com/world-maps/fault-lines-map.html). If some of these fractured, say by some sort of nuclear terrorism, volcanoes might erupt along the fault line and pollute the atmosphere. The Stromboli Volcano off the coast of Italy has been erupting more or less continuously for over 2000 years; so that shows it is possible; if you suddenly have strings of thousands of volcanoes, and at any given time hundreds of them are actively erupting and spewing particles, that might be enough to make your scenario reasonably plausible. But that can't be just one nuclear bomb going off; the size of a nuclear crater is an invisible pinprick on the scale of a fault line. It would take hundreds or thousands of nuclear bombs intentionally planted at weak points to cause this. So a terrorist act to reset the world order, perhaps. A kind of vengeance for injustices. This would also cause a nuclear winter, by the way, dropping global temperature significantly. Then all things Nuclear might be considered the culprit in this global disaster, and the nuclear power plants destroyed in the riots, by the people. All it takes is a well-placed truckload of dynamite, some missiles or something. Along with the collapse of governments and economies: As Covid has recently proven, just like many disasters before it, our governments are severely impaired in the midst of even small catastrophes. As the aphorism says, most countries are just three meals away from anarchy. And we can see for ourselves economies are fragile babies, easily destroyed. Anyway, because nuclear power plants require billions of dollars to build and a functioning orderly economy to deliver the necessary materials, they just have not returned. Yet I still fail to understand how this is the "age of steam". That age was extremely polluting, with coal and wood and fires in general generating the heat. I doubt in a world heavily polluted already, causing all sorts of respiratory illness, water pollution and general health distress caused by constant volcanic particulate pollution, that people would put up with polluting fires and industries at all. That crap would be shut down, by vigilantism if nothing else. As we have seen in industrial cities that already have high particulate pollution, compared to rural towns and farmland, the particulate pollution severely elevates all sorts of maladies, including autism, skin disease, lung disease, organ failures, and heavy metal absorption. I believe clean energy would rule the roost; including thermal solar (easy) and wind power (easy) for electrical energy. In that sense, "steam engines" with tanks heated by focused solar energy for the purpose of generating electricity would be quite prevalent; but it would be the age of electricity nevertheless. Photovoltaic panels would still work, all that is reduced is their efficiency. Good luck, I hope there is some food for thought in there. [Answer] **Population crash and decentralization.** Good old Road Warrior. That kind of world. People could build things but that would mean assembling a workforce and there are just not that many people in any one place anymore. But coal still burns and water still boils, and you do not need to find a copper coil or a magnet to make a steam engine do work for you. Steam powered vehicles burn whatever is burnable; coal where available, plastic from dumps, asphalt pulled from old roads, relics from the world that was. What mills exist are small and steam engines can serve their needs too. There are windmills to extract water from the ground to water the crops. There is not oil or nuclear power because there are no refineries and no mines. There is not solar power because there are no factories to build solar panels. There is still music, because people make it themselves. In this world there are flying things that use solar power. They can sometimes be seen high in the sky. They are left over from the war. They do not come down. People are glad they don't come down. --- But how do you crash the population? Infection could do it. We just had (are having?) a master class in that. I think the best account I have ever read of that scenario is Stephen King's The Stand. Almost everyone dies. War could do it. You can have that event be in the past. There is a different world now; the one you want for your story. I like the idea that the haze and grit is not well understood by your characters but is thought to be related to events on the other side of the world where something very bad happened. People talk about what it might have been and whether it is still going on. [Answer] Likely, technology can't go backward. Imagine for a moment that there is a doomsday that pushes us back to the steam age. Is there then a lesser doomsday event that pushes us back to the 1970s? We'd all be using Apple computers and playing pong? Nope. Because if we still had any electronics at all, we'd still have the 22nm process... and modern chips. Any event that knocks out that technology, knocks out all of it. What kind of doomsday would allow us to maintain the rubber seals and the rather sophisticated metallurgy that allows for steam engines? It's an implausible premise. It might even be true that any doomsday that topples our current technological civilization makes it impossible to rebuild. In the 1800s oil was so close to the surface there were places you could use a shovel to extract it... and today they have to put a platform out in the sea, go through 3 miles of water, and another mile or two below the ocean bottom to get to it. The first time, it was possible to use the 1800s technology to get the oil necessary to make it to the 1900s technology (just a shovel). If we ever have to go through that again, 1800s-like technology (the shovel) will not be able to go through 3 miles of ocean water, and another 2 miles of ocean bottom to get to whatever oil is left. And it's like that for all sorts of essential materials. We already used up all the easy-to-get stuff. No second chances. [Answer] In one word, 'religion'. A 'new religion' develops and becomes widespread among the poor and illiterate. The prosletyzations and ideology are basically 'knowledge and science did this to us - destroyed our civilization - our only hope of survival is to return to ignorance and destroy all knowledge and technology'. Thus, the masses all rise up and completely destroy anything that even remotely looks like science or scientific thought. All intellectuals are killed, all educational institutions destroyed, all progress is forbidden. All of human history is a successive series of 'catastrophe theory' and cusps. Sudden changes in thinking and ideology. Religious vacillations suddenly change the entire course of history. Buddhism, Christianity, Islam, all changed society in a period of a century. With the pressures of climate change, and the human suffering that will follow, it is inevitable that a new religious ideology will arise. Even today, we have the 'populist movement' vying to overthrow decades of moral and ethical progress, and their means of enforcement is ruthless capital punishment and complete annihilation of truth, facts, and knowledge. Fundamentalist zeal and mob power, driven by religious fervor, are brutally effective. However, the question is imprecise. By 'society', do you mean the entire Earth, or just pockets of human society? Throughout all of human history, 'human society' has never been a homogenous one. There has ever been a 'universal constant' of technology over all of the Earth, and to posit such is an entirely different question. There has never been a 'universal religion' on Earth, and it is very unlikely that there ever will be one. [Answer] ## Technology can't go backwards Honestly, from our current state of development there's no feasible way of reverting back to the age of steam, or any obsolete technology at that in general, without getting ourselves wiped out in the process. Massive resource shortages on a planetary scale simply do not occur overnight, they are gradual and provide humanity with more than enough time to adapt. Worst case scenario, come the apocalypse and the resources are dwindling, meaning they are increasingly harder to come by, factions will inevitably form and each one will try to create and exploit every single advantage it can over the rest. Another World War era will occur and large leaps in technology will be forced just for the sake of getting an edge over the enemy. In other words, there's no going backwards technology-wise, any faction that isn't able to keep up is eventually going to be wiped out. The only way to restrict technology would be to exterminate the generations currently using it and deny the knowledge of it to future generations, and there's simply no way to pinpoint where one technology ends and another begins. The only way to revert is to hit a hard reset button and the only way that happens is by a fantasy scenario eliminates 99.99% of the human population, leaving only the ones with the very basic knowledge. For your particular case, this would be definitive overkill. If you want to write a story that occurs in the age of steam, simply place it in the age of steam and build your world onward from there, don't bother with the apocalyptic technology reversal because you'll end up being tangled in it. ]
[Question] [ While trying to figure out how a civilization with 16-17th century technology could make airships I started to wonder how the wide availability of aluminum would affect a civilization. In our timeline aluminum started to become economically viable in large quantities in the late 19th century, one thing that I could see being a hurdle to overcome for a civilization attempting to widely use aluminum is the refining process. It takes a lot of power to make usable aluminum. How could a civilization that has not discovered electricity yet reliably mass produce aluminum and what uses would such a civilization have for it? In universe considerations: The industrial revolution started much earlier in this world around what we would consider the late 1500s. [Answer] **How could a civilization that has not discovered electricity yet reliably mass produce aluminum and what uses would such a civilization have for it?** I will only address the first part of the question. The most natural solution would be: the planet has minerals which contain aluminium in native or very reduced form. On Earth and actually everywhere in the solar system aluminium occurs as aluminium oxide. Most of it is incorporated in plagioclase and clay minerals. Native aluminium exists as an extremely rare trace mineral in mantle rocks, often alloyed with iron and with traces of silicon and magnesium or - in meteorites - copper and zinc. When a planet forms, the aluminium will always get oxidized. To get native aluminium there must be geological processes that produce it. You need a very reducing environment (low oxygen abundance) and high tmperatures (2000°C or so), so the planet should have high volcanic activity. Higher than terrestrial abundance of radioactive elements would help creating a higher temperature gradient and more volcanism. Native aluminium will form in the mantle, which is more reducing than crustal rocks, and will be transported to the surface by plate tectonics. Conditions should be dry, at least locally, to prevent the aluminium from reacting with water in geological time scales. High carbon abundance would facilitate the formation of native aluminium by carbothermic reactions like Al2O3 + 3 C -> 2 Al + 3 CO at temperatures above 1800°C. The process could also produce aluminium carbide (Al4C3). That would be a mineral from which aluminium metal would be relatively easy to recover (decomposition temperature 1400°C), but would again need very dry and reducing conditions to be stable. Even the presence of silicate would make the mineral unstable, leading to formation of aluminium oxide and silicon carbide (SiC). Naturally, a planet that possesses appreciable amounts of native aluminium would have to have a large amount of other reduced minerals, too: elemental silicon, silicon carbide, native iron etc., all continuously produced by subterranean smelting processes and then brought to the surface where after some time they get oxidized by water and air. It would be a society with a generally better availability of industrially important elements than we have. [Answer] It is pretty well known that all the primary production methods for producing aluminum use electrolysis. It also an energy intensive process - so researchers periodically look around for other ways to make a aluminum. There is a Russian research group that has claimed that through a chemical process at lower temperatures one can extract aluminum and potentially cut the energy consumption for aluminum production by about 1/2. The paper is "A new non-electrolytic aluminum extraction method", by Parenov et al., Without commenting of the legitimacy of the claims. The temperatures are high 300-500C, but with some ingenuity in reach, but the difficulty is that it is a process that has lots of steps and relies using reactive elements like Iodine and Clorine- so it transfers your problem from not having electricity to having a society that has a lot of chemistry knowlege. Then there are practical issues like having a good source of Bauxite and how they would prepare that. The actual discovery of aluminum was taking bauxite and mixing it with reactive chemicals, For example > > [Oersted](https://www.webelements.com/aluminium/history.html) reacted aluminium chloride (AlCl3) with potassium amalgam (an alloy of potassium and mercury). Heating the resulting aluminium amalgam under reduced pressure caused the mercury to boil away leaving an impure sample of aluminium metal. > > > This was expensive, but it did produce some aluminum. [Answer] Very difficult. Aluminium oxide is very stable and inert and it was extremely expensive until electrolysis. Historically, it was produced using sodium metal...but that's normally produced using electrolysis too. Henri Deville's 1825 process went: Hydrochloric acid + alumina -> aluminium trichloride, which reacted with sodium gives aluminium. Sodium can be produced without electrolysis by thermal methods by reacting sodium carbonate with carbon at high temperature. I'd suggest that this is your only possible avenue; Al was more expensive than gold prior to the Deville process. [Answer] Others have done a good job answering the electrical question, I will address the second: what uses would a civilization without electricity have for aluminum? The answer is going to be along the same lines as what we currently use aluminum for. So let's consider it's useful properties. This probably isn't an exhaustive list, but aluminum is tough, lightweight, cools off quickly, and is resistant to corrosion. In the real world it's also fairly easy to shape into whatever form you need, but that may or may not be true in your world (depending on the answers to your first question). Let's apply these. Computers and cars are obviously out, but construction is not. Buildings and boats of all sorts would make use of this. You mentioned airships in your post and we do make airplanes out of aluminum, so it'd be useful there as well. We also use aluminum in a lot of consumer goods, but your civilization may not yet be producing a huge number of consumer goods, depending on just how far your world is into its industrial revolution. If you have a lot of factories producing a lot of goods, aluminum is probably in heavy use there. If not, then there are probably still specialists using aluminum to make goods for the nobles who can afford it. [Answer] # Start with native aluminum. Most solutions involve Renaissance with electricity, which isn't going to feel authentic. But [native aluminum](https://en.wikipedia.org/wiki/Native_aluminium) does exist, in small quantities in unusual places. The deposit in China is thought to be associated with the [Nanjing Belt](https://www.reddit.com/r/UnresolvedMysteries/comments/53wm9i/the_nanjing_belt_a_belt_with_aluminum_ornaments/), an isolated instance of an aluminum artifact from ancient China. (There's also some yarn running around the internet about a bowl of peculiar metal presented to a Roman emperor who killed the inventor, and which was attributed to be one of those Chinese artifacts, but it was anything but certain and I can't remember a reference) ## Otherwise you have to get weird. In anything but a modern society, aluminum will be interpreted as a precious metal, as it was in the U.S. in the late 1800s. If you want to make it common enough to be cheap, you need a more reducing planet (no O2 in atmosphere, maybe), or postulate a naturally evolved organism that produces aluminum teeth/etc. biochemically. [Answer] Aluminum did exist and was produced in small quantities before electricity. There is a small pyramid of Aluminum at the top of the Washington monument in DC. It was considered a more rare and valuable material than gold. I don't see you producing a large enough quantity for an airship. Silk bags with light weight wood frame would be a better choice. ]
[Question] [ You see, I have this world that has the same planetary characteristics as Earth, and the people of the Snoopish Empire are building an [optical telegraph](https://en.wikipedia.org/wiki/Optical_telegraph#Iberia) net. The only problem they have is that their Empire is made of tens of islands separated by distances ranging from 30 km to 90 km. So the problem is: I need some type of optical telegraph design that can be seen at a distance of 90 km. (Yeah, I know that the curvature of the planet would occlude the towers if they were at sea level. However, I've done my maths, and if each tower is at a height of 250 m over sea level, they would have direct vision of each other at a distance of 90 km. And for this specific reason [and plot convenience] there are mountains of that height at the appropriate places.) So the only problem is about designing a system of optical telegraph towers that (with good weather and amateur telescopes) can be deciphered at that distance. -There's no problem with building an extra or 2 more towers, but not 3 more (in the same place), our budget is limited and the Emperor may decide that ships, while slower, are cheaper to rent. -We need to use technology that would be available to any civilization of the 1500s, for when we share the method with our allies in the younger continents. [Answer] If you have your heart set on using movable semaphore towers with 1500s tech, they're going to have to be quite large. But if you allow for simple telescopes, it's probably feasible. To distinguish the size, shape, orientation, etc. of an object like a semaphore tower, it needs to subtend a certain angular size. Features of an object whose angular size is smaller than this will just blur together and be indistinguishable. At a distance of 90 km, an object of size 1 meter subtends an angle of about 2.3 arcseconds. (There are 60 arcseconds in 1 arcminute, and 60 arcminutes in 1 degree.) This scales basically linearly; so an object 10 meters across would have an angular size of 23 arcseconds, 100 meters across would have an angular size of 230 arcseconds ≈ 3.8 arcminutes, etc. If you literally mean the technology level of the 1500s, then that precludes having telescopes at all (the first known telescopes were invented in the early 1600s), and you're limited to the resolution of the unaided human eye. This is around one arcminute; so at a distance of 90 km, the unaided human eye could only distinguish features about 25 meters across. The whole flag assembly might need to approach 100 meters in diameter. This is comparable to the diameter of a typical modern wind-farm turbine. However, if you'll allow for your world's version of Galileo to construct a 25x telescope in the late 1500s, then it becomes much easier. (Our world's Galileo constructed a 23x telescope in 1609.) With this magnification, it would be possible to discern features 1 meter across at a distance of 90 km. I would expect that a flag assembly of 4–6 meters in diameter would be able to transmit information. Galilean telescopes do have fairly small fields of view, which makes them awkward for astronomical purposes; but this is not nearly as much of a problem for your purpose, since they can be permanently mounted to point at the nearest towers in the network. [Answer] [Use a heliograph.](https://royal-signals.org.uk/Datasheets/THE_HELIOGRAPH.php) A 6 inch mirror will do you well. <https://royal-signals.org.uk/Datasheets/THE_HELIOGRAPH.php> > > Range of the Heliograph > > > > > The rough distance in miles at which the heliograph can be used, is obtained by multiplying the diameter of the mirror in inches by a factor of 10 miles. This range is governed by the angles at which the rays strike and leave the mirror and the state of the atmosphere. > > > > > The total lateral range (divergence) at which the heliograph can be read, is obtained by dividing the distance between the instrument and the receiving station by 107. The lateral range on either side of receiving station will be (approximately) half the total lateral range. > > > A 6 inch mirror will easily allow communication over 90 kms. You don't really need a telescope. You can put filters over the heliograph to change the colour to communicate a wider array of messages. The telescope could be for emergency communication where you build a big fire and use that when it's night or gloomy. # Use a 3 colour system for a small alphabet. Using common filters for red, green, and blue, you can send faster messages. Each message can be a short sequence of three colours. Red Red Red might be the symbol for stop say. You can either have an apprentice lift up colored cough, or design a small machine to move it automatically. The person on the other end can write down each sequence, and get a message. For shorter messages you can signal any messages to a receiver in a city or town below the mountain. For longer messages you can send a runner up or down the mountain with the message. # The outposts are self funding. The sender and receiver would basically be a farm where someone was moderately educated. They'd get their primary income from farming, but have a secondary income sending messages to other islands. The state may need to subsidize this initially, but soon local merchants and others will likely fund this to ensure their own advantages and speedy communication. [Answer] The first obstacle is tower height. Factoring in standard refraction and surface curvature you'll need a tower around 150m tall at both ends of the span. On a clear day that will give you around 115m obstructed height, leaving 35m of the top of the towers visible from either side. At that range you'll need either a good-sized signal panel (flags, shutters, whatever) or a fairly bright light to be visible without a telescope. If you're using signal panels they'll need to be at least 30m across to be *barely* visible to the naked eye, which has a minimum resolution of about 1 arcminute (1/60th of a degree). If you can build a pair of 150m-tall towers with an array of signal panels on top, you are probably capable of building some fixed telescopes on the towers to allow you to see smaller signal panels. As an aside, a shutter mechanism that has bright lights behind it is more visible, because we can see a light source that has an angular resolution smaller than our eye resolution. You still need the lights separated enough to resolve *which* light you are seeing. Moving on, let's consider the coding. While you can use a single light to transmit all of the information you need to, but if you're relying on human perception your bandwidth is going to be quite low since each signal has to be long enough to be visible when the observer blinks. Having multiple signal bits is harder, from an engineering perspective, but it greatly increases the bandwidth available... to a point. You need to keep the total number of signal panels down to the point where a human can unambiguously recognize each valid combination of states in a short amount of time. I honestly can't tell you where the break point is, but I expect that you should be able to get upwards of 5 bits of data (32 symbols) into each frame without too many problems. No, that's not 5 signal panels, that's 32 combinations of 6-7 panels. Yes, that's 50-75% worth of wasted bandwidth, but there are a lot of combinations that are difficult to read accurately because they're too similar. Consider a 3x2 array of signal panels. Single bit combinations are mostly out since it relies too much on the observer being able to figure out which particular bit is lit, and they need to do so quickly. So that's 6 possible combinations out of the way. Same deal with two adjacent bits - which two are they? There's another 7 bad ones we need to get rid of. And so on. So how many *good* combinations are there for a 3x2 array? Not as many as you might think. There are a couple of rules to consider: 1. All combinations must have at least one light on in both rows. 2. No combination may be shifted on the grid, which means: * No empty left column. * No empty right column. Seems pretty simple. We can enumerate those fairly quickly (there's only 6 bits of data here after all). Here's the full list, split by common bottom row values: ``` ☒☐☐ ☒☐☒ ☒☒☐ ☒☒☒ ☐☐☒ ☐☐☒ ☐☐☒ ☐☐☒ ☒☐☒ ☒☒☒ ☐☒☐ ☐☒☐ ☒☐☐ ☒☐☒ ☒☒☐ ☒☒☒ ☐☒☒ ☐☒☒ ☐☒☒ ☐☒☒ ☐☐☒ ☐☒☒ ☒☐☒ ☒☒☒ ☒☐☐ ☒☐☐ ☒☐☐ ☒☐☐ ☐☐☒ ☐☒☐ ☐☒☒ ☒☐☐ ☒☐☒ ☒☒☐ ☒☒☒ ☒☐☒ ☒☐☒ ☒☐☒ ☒☐☒ ☒☐☒ ☒☐☒ ☒☐☒ ☐☐☒ ☐☒☒ ☒☐☒ ☒☒☒ ☒☒☐ ☒☒☐ ☒☒☐ ☒☒☐ ☐☐☒ ☐☒☐ ☐☒☒ ☒☐☐ ☒☐☒ ☒☒☐ ☒☒☒ ☒☒☒ ☒☒☒ ☒☒☒ ☒☒☒ ☒☒☒ ☒☒☒ ☒☒☒ ``` With just those two rules we've whittled it down to 32 viable combinations - 50% of the 64 possible combinations of 6 lights. With training I think an average human operator could be trained to recognize 2 of these symbols per second, maybe more if they're using a keyboard of some sort to enter the symbols. That's upwards of 10 bits per second worth of bandwidth... which is slow, but far from useless. To put this into perspective, highyly skilled amateur enthusiasts can transcribe Morse Code from audio (via keyboard) at about the same rate - 60 words per minute, or approximately 10 bits per second (assuming: 5 characters per word, ~5 symbols per character and factoring for inter-character and inter-word gaps). While there are people who can go higher, first class licencing requirements are much, much lower: 25 WPM (~4 bps) for text. ]
[Question] [ Space is mostly empty. There are few planets which could be life sustaining and even on those we are unlikely to find anything living (unless we contaminate). This means that on planets beyond our solar system, stranded colonists would have very different conditions to work with. No matter how "earth-like" a planet is, it may have the same mass, constitution and distance from the sun but the fact remains: there's no life. This means no wood, coal, fossil fuels or natural gases to work with. Why am I hammering this point so hard? My setting has a planet inhabited mostly by robots. Humans play little to no role there. So its mostly robots going around with their business, mostly because a pre-terraformed planet is inhospitable to humans (so they have that going for them). Their forefathers were stranded colonists so they have no access to imports. ## How does the lack of life on a planet affect technological development? For the sake of believability, **I need a list of branches of technologies that couldn't exist without our flora and fauna**. I expect many chemicals to be unavailable, however I am woefully unfamiliar with the industry. I don't even know where to start. Hopefully you can help me with that. [EDIT: I've given my question a complete overhaul to make it clearer but in essence the questions is the same.] [Answer] You've already touched on the biggest problem to technological development; the colonists will struggle to make carbon monoxide and that means they will be unable to crack any oxides without electricity and they won't be able to crack oxides with poor water solubility in any great volumes *at all*. That means that large scale use of metals is probably a non-starter unless they have a *lot* of generation capacity going to waste. The biggest problem the colony faces is not lack of materials to build technological artifacts though, it's the atmosphere; there will be little to no free oxygen and the composition will probably be highly corrosive making plastics, composites and ceramics a must for external structural elements. The lack of bulk carbon feedstock makes plastics more difficult to manufacture but the lack of oxygen means the atmosphere is likely to be high in volatile hydrocarbons, particularly [Benzene](https://en.wikipedia.org/wiki/Benzene) which can be extracted through [cyro-distillation](https://en.wikipedia.org/wiki/Air_separation#Cryogenic_liquification_process) and used to make polymers. The lack of free oxygen may also effect the colonists ability to produce bulk ceramics because it limits their ability to maintain an oxidising, or even neutral, atmosphere in the kiln which can be vital for many operations. Composites of boron or silica in polymer resins are likely to be the most lasting and cost effective materials. Technology is not likely to evolve on a world under the circumstances described, even if the colonists had a large enough population to make a go of it genetically, there aren't enough people; it is estimated that you need ~300 million people to support a single microchip factory (that's just the logistics to run it, not the consumer base to buy the output). Furthermore the environment is also going to be so hostile to the components of most gadgets as to render the working life of much vital equipment extremely short and thus the lifespan of the colony is going to be strictly limited. **Unless** the technology they're using is based in [molecular printers](https://en.wikipedia.org/wiki/Molecular_assembler), then they have the option to use a far wider range of feed stocks and use them in reaction paths that are either impossible, or just impossibly expensive of time, wastage, and/or energy, using traditional chemistry. [Answer] No life ‚áí no longer chain hydrocarbons ‚áí * no lubricants for your robots * no rubber for any elastic/flexible membranes those robots would benefit [Answer] Probably not what you're looking for, but I've always had a theory about such a machine race. Setting aside the lifeless world for a bit as I'm not a scientist and another answer seems to already address the practical issues with that. With a race of robots, I theorize that, assuming the robots possess intelligence comparable to huamns, are as innovative and creative as humans, and has as complex social/civilization and philosophical structure as humans, they would actually strive towards improving their designs to becoming more like organic life. Metallic lifeforms has many disadvantages. They cannot heal/regenerate. They cannot independently generate energy. Even solar panels and battery cells have limited life span. In some cases, they cannot be repaired without being "turned-off" which leads to an interesting philosophical question for the machine race - is it the same continuous stream of consciousness / electrons forming your thought matrix if you are turned off then back on? Megaman's "older brother, Protoman, actually posited this as a surprisingly deep philophical question as part of his origin story, which was why he rejected Dr. Light's proposed upgrade to give him a perpetual power source but requires fully shutting him down to install it. Even if nanomachine swarms exists, it needs material to conduct the repairs. Metals are pretty expensive and energy intensive to extract and use. By contrast, carbon-based organic material can be easily extracted on a habitable planet and self-replenishing. If such a machine race existed, and decides to colonize other planets, would they not design new robots that can harvest and utilize these organic material. They might devise a container to store these materials, perhaps in the center mass/torso of their body, like a stomach. This container likely connects to microfactories that can extract material and distribute to the rest of the machine, but to ensure all materials are sorted through properly it likely will go through a narrow tube, but wraped around compactly to fit inside the torso for ease of carry. However, narrow tubes don't seem like the ideal factory to build your machine parts, you might want autonomous nanomachines that reside in said tube to process these materials. Sound familiar? That's a human gut. An advanced machine civilization that is as socially complex as humans would also develop very advanced wifi protocols to diagonose each other, but with enough firewalls to protect each individual machine's privacy and prevent being "mind controlled". Doesn't this sound a lot like human empathy? Your world need not follow my theory where the robats eventually take an organic form, but I do think there may be some ideas that could be adopted. They can easily have a machine stomach and machine gut that processes strictly minerals, but I do think they would devise a lot of technology to overcome many inherent shortcomings that afflict our modern day perception of robotic designs. [Answer] **An ever stronger need for processing power and efficiency** I don't know if these robots are under threat from other bots in the scrap/material/part/lubricant harvesting sense but whether or not they are shouldn't affect my answer too much. The way I see it, mechanical life would try to increase their processing power as much as possible while trying to innovate more and more ways to efficiently perform tasks like energy and resource harvesting, moving around, colonization of resource zones and establishment of infrastructure, and so on, and if they can't be any more efficient they'll invest into energy recapture systems to make use of energy that they couldn't efficiently make use of(like waste heat) in the performing of a task and re-use that energy for something else. What's important to bots is the ability to solve problems and increasing their runtime, this would necessitate better processors and better ways of using and harvesting energy, along with trying to innovate materials and designs that last longer than what they currently have, or wear down less, to reduce the time, energy, and resources spent on repairs which would be a huge waste in their eyes when it'd be more efficient if structures didn't break down in the first place, but that's not really attainable so the best they can hope to achieve is to have nearly everlasting forms and nearly perfectly efficient energy harvesting and usage methods. [Answer] (Note: I don't have relevant expertise, so a lot of this is speculation.) There are a couple problems I see on a planet without life. The first problem to consider is accessing carbon. Most carbon [would be](https://en.wikipedia.org/wiki/Atmosphere_of_Earth#Second_atmosphere) in the form of carbonates, which would have to be mined, and the carbon would have to be extracted. If the planet is cold like Mars, there might be frozen carbon dioxide. There would be carbon dioxide in the atmosphere and oceans as well, but extracting useful quantities would be difficult would require processing huge amounts of air/water. Carbon dioxide and carbonates are quite stable, or they would react with something else. So they will require either energy or some reactive chemical to convert into a useful form. And without biotechnology, catalysts are limited, so at some stage they'll need large amounts of energy to access some necessary material. That leads to the second issue, energy. Without hydrocarbons available, the main energy sources will be solar or wind/water/nuclear/geothermal powered turbines. The major problem I see here is a lack of [plastics](https://www.investopedia.com/ask/answers/042015/what-commodities-are-main-inputs-electronics-sector.asp) for insulating wires and electronics. Ceramics will be able to fill the role of plastics in some situations, but they will also be partially limited by the lack of organic precursors. Since electricity is so useful, I think they will find a way to make it work, either by finding inorganic substitutes or by devoting a large portion of their energy to producing the plastics needed for upkeep on their energy generation. However, this energy generation is likely to be inefficient, at least until they can take advantage of economies of scale. This also makes mining, smelting etc. more difficult. The last problem is organic synthesis. I don't think much is impossible. Simple reactive molecules can be produced by applying energy or heat to nonreactive materials. These can then be used to synthesize more complex molecules. Humans also have large amounts of [microbes](https://en.wikipedia.org/wiki/Human_microbiome) living on and in their bodies. The fact that there are a small number of humans means they can eventually redevelop biotechnology - although most microbes likely won't survive outside human habitats. The problem with organic synthesis is that it will be extremely expensive due to the lack of available carbon. It will also take a lot of effort to figure out how to make complex organic molecules. Thing like biologically-derived medicines and catalysts will be the most difficult. So to sum up: 1. It will be possible to make most substances, or acceptable substitutes, but specific complex organic molecules (i.e. medicines) will take years or decades to develop and can only be made in tiny quantities. 2. Any organic (carbon-containing) materials will be require a lot of resources. Large plastic objects will be prohibitively expensive. 3. It may be difficult to transmit electricity. This suggests a few general principles to me: 1. The technology is designed to take direct advantage of natural resources. Technologies like geothermal forges, wind/waterwheel-powered factories, sailboats, use of natural caves for shelter, etc. will allow the inhabitants to avoid wasting electricity. 2. The technology is designed to produce as little waste as possible. A lot of effort is put into designing technologies efficiently to avoid waste - think things like honeycomb designs for metal struts to avoid using unnecessary material. The effort of designing something correctly is always less than the cost of using an inefficient design. 3. Organics are mostly only used for electronics, medicine, basic needs like growing food and clothing for the humans. Most large objects are made of metal, glass, rock, cement, or ceramic. 4. Reducing, reusing, and recycling is extremely important. The limits on plastic are a big difference. Almost everything is painted to prevent wear and tear - it will need to be armored or glazed or galvanized or covered in cement or clay instead. Rubber tires are crucial for transportation - expect more boat, rails, and walking robots. There's no wood - furniture will likely be made of concrete, and bedding might be made of sand, or flexible wire mesh. Clothing and protective gear would be difficult to make. The human population will likely remain small, due to the large amount of carbon required to sustain human life. [Answer] A factor to consider is that the elements in the crust may be less subject to mining and extraction, and thereby be less accessible. For instance, iron (Fe) is found in a distinct layer of rock which was associated with the oxygenation of the atmosphere, a process that was caused by the development of photosynthesis in living cells. There are hypotheses (perhaps less well documented, or at least less well known) that other mineral deposits are biogenic. To the extent that the deposits are strictly due to chemical and mechanical processes, they could still exist and be extracted. To the extent that biological processes concentrate the minerals to extractable levels, getting the raw materials for machine life will be a difficult bootstrap problem. ]
[Question] [ Scratchera are a Revelian race, a race of rather small and agile anthropomorphic lizards. On Reaville, archosaurs and other saurians have grown to take the place of most modern-day mammals, which is relevant because Scratchera were more-or-less analogous to squirrels or monkeys. However, soon after they gained intelligence from whatever caused their uplift, Scratchera swiftly overtook the others in terms of technological advancement, and demonstrated unusual engineering capabilities, with particularly talented individuals being able to disassemble or reassemble a firearm in seconds. The question here is, *how is this possible?* That is rather sophisticated engineering, and would require this species to already be capable of and gifted in object manipulation, tool use, and general building. **But OP, don't you have some idea how this could have happened already?** Yes, indeed I do, and the point here is to polish this and see how feasible this scenario is. The idea is that Scratchera, due to a lack of hiding places or a lack of natural hiding places that work, survive by creating protective nests that are harder to get into or penetrate than natural hiding spots like cracks in rock or tree hollows. In other words, a natural nest-building trait evolves through natural selection (ie. predators that claw apart rocks or trees to get at Scratchera) into a gift for resilient architecture. Magpie syndrome, which could develop before or after this gift enters the gene pool, further augments this by leading Scratchera to gather and utilize shiny minerals, gems, ores or metals in their construction. An arms race then develops, where the Scratchera who are better at collecting and using metals and minerals instead of less solid materials like twigs, mud, and sap, are the only survivors. Yes, I recognize the Scratchera who develop and utilize better *weapons* as opposed to shelters could survive just as well as the architects, and I do believe they will evolve into a distinct subspecies. **TL;DR: given the right conditions (weather or predators, most likely) could a species of lizards with highly advanced engineering abilities (comparable to primitive or maybe even modern humans) feasibly develop?** **Specifications for Best Answer:** 1. The best answer will explain how feasible this scenario is, and what conditions would be required to make it happen. This is critical, as while I have a good idea on what I want to keep in Reaville, I would appreciate the extra help on creating a real ecosystem out of Reaville. =) 2. The best answer should also account for the possibility of Warmakers (the weapon-making subspecies mentioned above) and how that would influence the survival and/or development of Architects, which will be developing **not just** structures but **also** armor and shields to better defend themselves while they're out-of-doors as time goes on. **Please let me know if my question needs improvement, I'm open to and appreciate feedback as well as answers!** [Answer] /soon after they gained intelligence from whatever caused their uplift/ [![chaser](https://i.stack.imgur.com/ftlZum.jpg)](https://i.stack.imgur.com/ftlZum.jpg) **Scratchera were bred to be what they are.** [Chaser and his 1022 toys](https://www.cbc.ca/radio/asithappens/as-it-happens-tuesday-edition-1.5230248/chaser-the-border-collie-that-could-recognize-more-than-1-000-words-has-died-1.5230263) Chaser knew the names of 1022 toys. And not just that. Chaser was really smart. How could a wolf be so smart? Chaser the border collie was no longer a wolf. Thirty thousand years of breeding made Chaser what he was. So too your Scratchers. They were uplifted. It took a while. On the way, they became something else - the things they are today. Something wanted the Scratchers to be how they are. It is not an accident. Maybe those things are still around? [Answer] **A lizard is a small reptile with a physiology not handy for engineering** You creature may develop intelligence. But *engineering* also involves building things. At first glance, I'd think lizards - reptiles, limited size, close to the ground, quadruped - would have a difficulty with "engineering", that is shape wise. Also reptiles are cold blooded animals, resulting in low energy, slow activity.. Your lizard may have a talent to build a well protected nest, it may have creative dreams, but I see a few issues with it.. in practice. Grounded limbs, rigid fingers, small size. [Answer] **The Architects die out in the hunter-gatherer stage** Similar to how Sapiens eliminated Neanterthal, the Warmongers will eliminate the Architects during the hunter-gatherer phase. *Note: The below example is for ground-based species. For arboreal species the explanation is analogous. Just replace "spear" and "bow" with the appropriate stabby and shooty weapons, and "moat and drawbridge" with appropriate fortification. For example hollowed out tree trunk.* During the tribal nomadic phase, the Warmongers have invented the spear and bow while the Architects have only invented the moat and drawbridge. The bow and spear are superior in the hunter gatherer stage: (a) You can carry them with you when your tribe has exhausted all the nearby food sources and moves to a new area. On the other hand, the fortifications need to be built again each time you move. (b) You can build one spear in a day. At the end of the day you have a spear. You can stab things with the spear. On the other hand, in a day you can build a small section of moat. The section is no use until you have build the entire moat. This takes weeks. By then it is already time to move to a new place. (c) A tribe of Warmongers will kill a tribe of Architects if they share the same area. The Warmongers win most fights outside the Architect fortress, since Warmonger spears and bows are more deadly than Architect sticks and rocks. The Architects' main defence is run back to their fortress. But there is no food source in the fortress. So the Warmongers just starve them out. The upshot is that the Warmongers spread worldwide faster than the Architects, killing any they encounter along the way. After a few hundred years the Warmongers are the dominant species on the planet; all large predators have been eaten; and the Architects only remain on a few isolated islands and mountain ranges. [Answer] **Evolutional Pressures** In humans, our diet allowed for the developed of a larger brain. Our chosen environment initially forced humans to develop tools for hunting and fighting. Shelter was what ever cliff over hang or large tree they found for millions of years. With your lizards, if their environment does not require constant fight for survival and they feed on a variety of soft bodied grubs, the need to develop weapons is not there. If the environmental pressure for this lizard to focus on shelter (to hide or protect from aggressive predators, such as the warmongers) for survival where some random cave wont do, then evolutional pressures would make the more creative of the species win out. These lizard would start out simple, a little burrow underground. Over time, as they become more social and communal, a simple hole wont work. Their burrows would become more complex, with labyrinths, functional rooms, water drainage, ventilation doors etc. All of this has been developed on Earth by non-humans, so its possible, such as ants and termites. As they improve their environment, their physiology will change as well. Eventually, complex tools will develop, increasing more sophisticated burrows and a better understanding of engineering. To better survive, their diet would need to adapt, become more omnivorous. They would develop fungi farms, grub ranches etc. Once they can harness fire, their diets would expand, spurring further physiological changes and, as a side benefit, increased technological advancements. Eventually, after millennia hiding underground in their cities, they emerge to find the world dominated by this warmonger species. They two do not occupy the same environment, so very little hostilities erupt between them. Instead, the lizards provide a trade of metals and resources only found under ground as the warmongers, still finding shelter under trees, provide access to timber and other goods found only in the sun lit surface. ]
[Question] [ I have a large insectoid creature with compound eyes in my story. The creature’s habitat is prone to sudden dust storms; as a result, I was planning to have it evolve a set of eyelids so it could protect its delicate eyes from particles. Is it feasible for a creature with an exoskeleton and compound eyes to have a set of eyelids? No arthropod on Earth has eyelids (as far as I’m aware) so they may not be necessary or possible, but they would be nice to have for making the creature more visually expressive. [Answer] I don't think eyelids are needed for insect eyes: you are probably familiar with the image of an insect washing itself, eyes included, by rubbing it with its fore limbs. [![enter image description here](https://i.stack.imgur.com/Df1T1.jpg)](https://i.stack.imgur.com/Df1T1.jpg) I am pretty sure that if I was to rub my eye's bare surface with my hands it would be all but pleasant. The evidence that they do this on a constant base for several generations suggests that the compound insect eyes are more sturdy than the vertebrate eye. Moreover, insects do live already in very dusty environments, and none of them has evolved eyelid, meaning their absence is not a game killer. [Answer] **As a slight frame-challenge**: An alternative possibility is to have the eyes on moving stalks which allows the animal to "flip" them under protective coverings. Being on the "head" and near the mouthparts would allow for a moist lick to clear the external lens-cover as per [this inspirational video](https://www.youtube.com/watch?v=nGk5jAlc1Fc) of a crab cleaning it's eyes. ]
[Question] [ Could muscle-powered weapons be made to take advantage of superhuman strength, or Would material limitations get in the way? Assuming: * a Viking Age (say 800-1000AD) level of technology * materials available in RL medieval Europe * strength about 6x the upper end of the practical human range. This is maybe a bit harder to define, but basically I am talking about overall upper body strength, not just one measure e.g. the bench press... What I have in mind are near-humans who are larger and more robust than RL humans, so both greater muscle mass and proportions that increase upper body strength at the expense of e.g. running endurance. How much of this additional strength would the materials and technology allow taking advantage of? Could real-world wood make, say, 500-pound-draw-weight bows (without complex compound-bow mechanisms beyond this tech level)? Could Viking Age metallurgy and swordsmithing make swords that could stand the full impact of being swung by someone with this level of strength? If not, would axes or maces be better? [Answer] **For ranged weapons** The quality of steel in the 800-1000AD range was generally not good enough to make an arbalest, and designing a longbow able to take much more than a 100lb draw is not easy (see comments for more details). Multi-arm or slat laminated arm crossbows have also been suggested, but are grossly unreliable and not invented until after 1000AD. That said, even if you could use an arbalest or or multi-arm crossbow, there was one weapon that already existed by 800AD which could outperform either weapon by a large margin: the manuballista. Manuballistas were small enough to be hand-portable but were very front heavy and weighed about 100lb making them impractical to be hand-fired by a person of normal strength. But, with super strength a person could use a manuballista as though it were a hand drawn crossbow. Manuballista used torsion coils instead of tension arms to accelerate their missiles, and as a result had ranges and speeds much greater than any historical bow or crossbow design. Their projectile speeds were more similar to modern fiberglass compound crossbows, and they had massive stopping power from the weight of its missiles. So, while the arbalest and longbow beat out the manuballista in our own history thanks to their portability, the manuballista is a much more powerful weapon than either and the technology can be scaled up to much greater damage potential using the same quality of materials. **For melee weapons** The limitations of steel apply here too, but not nearly as much. When you look at sword fighting manuscripts prior to the introduction of the finery forge, most defensive sword maneuvers were deflective or hilt guards and most strikes were draw cuts. These techniques are designed to limit how much strain you are putting on your blade which suggests that 1x human strength was enough to bend or break these swords if not used wisely. The introduction of better steels in the 1200s came with the introduction of many new block guards and more acute weapon tips for thrusting when steel weapons started to become stronger than humans could reasonably break. We also have plenty of literary records from civilizations all across Europe of wooden handles and spear shafts snapping in combat. This is all to say the 1x human strength was already pushing the available materials to their limits. So, a super strong human would not benefit a whole lot from using actual viking weapons, but unlike wooden bows, metal technology could be expanded to make bigger heavier weapons for your super strong humans. So, instead of a typical viking sword which would be about 2-3lb with a blade profile of ~ 3 x 50 x 750 mm, you could give them a much chunkier 1-handed sword with a blade profile more like ~ 7.3 x 120 x 750 mm weighing in at 12-18lb, and still maneuver it with almost the same dexterity. More strength though does still have its limits here. One limit is that your sword may be 6 times as heavy, but it won't be 6 times as lethal. the thicker you make the blade, the more cut resistance it will have. The edge will also still deform at the same acuity as a normal sword, so you will need to make it duller to survive an impact at full force. Lastly, you may be 6x as strong but your body still has the same inertia; so, fast complex maneuvers with overweight weapons may still throw off your balance. So yes... a bladed weapon with 6x the cross-section would be more lethal than a normal one, but not by as much as you would think. Instead, I would probably suggest a solid steel mace or war pick instead since they would be less affected by edge limitations and benefit more from greater strength. Basically, picture what a 12-18 lb sledge hammer can do to solid concrete, then imagine what it would do if it could be wielded 1-handed with the dexterity of a ballpein hammer and you are looking at a very devastating weapon. **For Armor** This is actually where super-strength would be the most helpful. Preindustrial soldiers would often carry up to 70lb of armor pushing their bodies to the limits of what they could carry and fight in. But with 6x strength, your warriors could now carry hundreds of pounds of armor and still remain relatively unencumbered. Furthermore, a really heavy suit of armor could add inertia to your warrior allowing him to wield really heavy weapons without loosing his balance. [Answer] With the weapons of the period I think the most immediate benefit would be removing one the biggest shortcomings of crossbows, putting them on the same level with bows when it comes to [cadence of fire](https://en.wikipedia.org/wiki/Crossbow#Medieval_Europe): > > Later crossbows (sometimes referred to as arbalests), utilizing all-steel prods, were able to achieve power close (and sometime superior) to longbows, but were more expensive to produce and slower to reload because they required the aid of mechanical devices such as the cranequin or windlass to draw back their extremely heavy bows. Usually these could only shoot two bolts per minute versus twelve or more with a skilled archer > > > With 6x the strenght of a normal human, the superstrenght would be right on spot to level the cadence. If you pair this with the advantage of crossbow over bows, being that it required a shorter training to be used, you are significantly shifting the power balance between armies, because a killed archer is more expensive to replace than a killed crossbowman. [Answer] I point out that elephants are a lot stronger than 6 times human strength, and in Asia war elephants have been fitted with blades attached to their tusks. War elephants have also been trained to use w swords with their trunks. And some war elephants have been trained to pick up large iron chains and swing them at enemy soldiers. So if versions of hand weapons strong enough to be used by elephants without breaking could be made, I guess that versions of hand weapons strong enough to be used by people with merely six times human strength without breaking could also be made. [Answer] Your Super-Soldiers would have a powerful advantage in cheap and plentiful and effective, if very unsexy, thrown weapons in the form of rocks. A typical adult male human can throw a .45 kg rock at 36 m/s. Your super-soldiers can either throw the same rock much faster or heavier rocks just as fast or some combination in between. Throw in the mechanical multiplier of an Atala-like tool such as a sling staff and your super-soldier is a walking siege engine. I agree that the quality of steel was poor in your selected time frame, but iron was good enough. A long thick iron sword would be very effective in combat since the targets are not wearing steel armor. Weapons like Broad Swords used their mass to inflict damage, and not the cutting edge; the heavier and faster the weapon moves the more damage it causes. I'd think something like a flail, another very unsexy weapon, would be the best suited to your super-soldiers' strength. It has a long shaft that can be used for defense -- blocking attacks -- and its swivel head flaily part would deliver a tremendous force multiplier. Similarly, pole arms like a halberd would significantly more dangerous in his hands since they could be longer than normal, with heavier axe-bits, and still be wieldy in their hands. The weapon's shaft would be the limiting factor on the weapon's length and mass, since you can't really make it thick as you want since the super-soldier still needs to grip it with their normal sized hands. ]
[Question] [ What would be the repercussions of all non-human animals larger than a mouse dying around 16/17th century in a certain region or across the globe? Would it mean eventual extinction of humans, as they would not be able to get some necessary nutrients? Or just a regular apocalypse, where few would survive by eating perhaps insects (in addition, of course, to plant based diet)? Would there be a sudden increase insects in the affected regions? **EDIT:** I am interested in broad-strokes results and most important effects to the human civilization. Famine, lack of beasts of burden, massive growth of rodents due to lack of predators and subsequent die-off are good examples. The most important question for me was whether humanity would go extinct or whether it could survive. The second, broadly speaking, would it be possible for the humanity to recover, even if after a very long time. [Answer] ## Death. Humans are animals, larger than a mouse. (changed by OP) If you meant to ask "What would be the repercussions of all animals larger than a mouse ***other than humans*** dying around 16/17th century in a certain region or across the globe?" Loss of all food animals. Loss of all Marine fisheries. Loss of all work animals. Most notably loss of horses (transport) and plough animals. Loss of certain classes of materials. No more leather. No more wool. Not even bone. (exceptions, see beefburger, below) ## Food, and society: People would starve in their masses. Agriculture without the ability to plough will produce much less food, transport of crops without any beast of burden will be incredibly problematic. In that era water transport was a bit primitive, but functional. But there were no mechanical transport of any kind yet, so the very best we could do would be hand carts. Equally, plowing could be done by hand, or with human pulling teams. Reinstitution of slavery, anyone? A suitable underclass of humans designated as beast-of-burden? Humans could survive. Civilization will be set back a couple thousand years, and will have a very hard time recovering with no access to any domesticated animals. Unless you turn your slaves into domesticated animals? Not my sort of world, where subjugated classes take on the roles of horses, oxen and beefburgers. ## Ecology: Loss of all animals larger than a mouse? So. No predators, no raptors. finches are fine, doves, maybe. crows & the like are gone. and... mice are FINE. Insects are FINE. Fortunately so are bats. Phew! Between them and other insects, there will be a measure of control of insects. With none of their predators remaining, small rodents will go berserk. First a couple seasons of population boom, then complete denuding of the countryside, then utter devastation of a mass dieoff. This cycle may repeat, or may end in a permanent wasteland. [Answer] # Regular apocalypse I'm assuming you are excluding humans themselves from the culling. So we have animals smaller than mice + humans survive the event, all other animals dead. According to Wikipedia, [Vegetarianism can be traced back to three millennia before Christ, and veganism can be traced to the 10th century](https://en.wikipedia.org/wiki/Veganism#History). I remember reading somewhere that some gladiators in Rome were also vegans, which makes the whole thing older. Now while it's possible to live on a vegan diet, it's not for everybody - most people who decide to become vegans have to go through a whole process, and the logistics for it are not in place for all people at one given time. For societies that really depend on meat, specially pre-20th century technological level, forcing everyone into veganism will cause dietary shock in most, and there won't be enough quality food for everybody. It is hard to quantify the effects, but you're basically facing famine. In places like the north pole, where at times your only way to have a meal is to hunt or fish, it may be doom for everyone - otherwise as long as you have arable lands and people know how to grow food, at least some would survive. --- By the way, modern nutritionists claim that vegans are vulnerable to b12 vitamin deficiency; which might be prevented with a diet rich in certain algae. Check the wiki above for further details. This means populations living on coasts might be more healthy than populations living on the countryside. ]
[Question] [ How small can a planet with rings be? It doesn't have to be inhabitable, but it must be a planet (not a dwarf planet). [Answer] I agree with the answers posted so far (the gist being that any object which is a planet can have rings), but I also wanted to talk about real-life examples of low-mass bodies with rings: * **[Chariklo](https://en.wikipedia.org/wiki/10199_Chariklo)**, a minor planet $\sim$230 km across, has two rings approximately 400 km in radius. * **[Chiron](https://en.wikipedia.org/wiki/2060_Chiron)**, another minor planet $\sim$200 km across, has a ring system about 325 km in radius. * **[Haumea](https://en.wikipedia.org/wiki/Haumea)**, a dwarf planet $\sim$1000 km across and weighing in at $4\times10^{21}$ kg (0.07% the mass of Earth), has a ring about 2300 km in radius. * **[Rhea](https://en.wikipedia.org/wiki/Rhea_(moon))** a moon of Saturn roughly half the mass of Haumea, was thought to have rings between 1000 and 2000 km in radius, but the observations have been disputed. This strongly suggests that any body that can be considered a planet could have rings, assuming it tidally disrupts material in a close orbit near the [Roche limit](https://en.wikipedia.org/wiki/Roche_limit). It also suggests that the radius of such a a ring system would reasonably be about 3-4 times the radius of the planet, which fits in nicely with some reasonable assumptions about the Roche limit. Certainly, it would be difficult to form a ring system because it's difficult for low-mass planets dies to capture moons or other small bodies. The giant planets in the Solar System have substantial moon and ring systems, whereas the four terrestrial planets currently sport only three moons between them. However, it's clearly not impossible. [Answer] From the definition of [planet](https://en.wikipedia.org/wiki/Planet) > > A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and – acconding to the International Astronomical Union but not all planetary scientists – has cleared its neighbouring region of planetesimals. > > > The minimal sized body which can be classified as planet is also the minimal sized planet which can have rings. Rings are made by small particles orbiting the body. [Answer] Any planet can have rings (If it has things that can collide or fall below Roche limit in orbit around it) but IIRC the size of the planet, and the exact composition of the rings will determine *for how long*. An Earth-sized planet wouldn't be able to hold on a ring system if it had one for more than a few thousand years, and the rings of Saturn should be gone in a hundred million years. ]
[Question] [ So, I was looking at what defines the most interesting type of forcefields, and there came an interesting kind of forcefields that, rather than deflecting or dispersing energy, seems to absorb energy. Niven calls it the **Langston Field**, while Traveller calls it the **White Globe**. Now, a forcefield that can freely absorb energy, is useful not just for defence, but for stealing power to power one's own engines. To be slightly restricting and not be too vague, it is obvious for both cases that the energy in question is just standard radiation, light, heat, electricity and such. Obviously, I ask for its feasibility, but that would be too much in regards to our world. To give some room for less hardness in its feasibility, we can assume we have mastered lots of particle physics by at least a millennium's worth, where we properly control matter from subatomic particles down to its quarks, and even their antimatter or supersymmetric counterparts. Maybe we even collect dark matter and fundamental force bosons. What ideal particle or force should be used for such a shield? Or, if that won't work, then we could go back to our multiverse theory I have been making multiple questions of. If some of the four fundamental forces were different in someway, could it be more possible? *Note that it also has to be a particle-based field if anything. Though the one who talked about solar panels, yeah that was really funny.* [Answer] **Microscopic black-holes fabric** You want something that absorbs any kind of energy? It's a black hole! Now, you want a small one, shaped like a surface, and that you can move around. A solution is to have a "fabric" of [microscopic black holes](https://en.wikipedia.org/wiki/Micro_black_hole), organized so that radiation, energy or matter coming from any direction cannot get through. Black holes are not required to have all the same size, so a disposition like the following can do if it's thick enough, for example: ![Packed spheres](https://i.stack.imgur.com/r7kdq.png) (Make sure to keep some room between them so they don't merge, though.) Now, how do you keep them organized, prevent them from merging, and move the whole shield around? Use electrically charged black-holes such as [Reissner-Nordström black holes](https://en.wikipedia.org/wiki/Reissner%E2%80%93Nordstr%C3%B6m_metric), and confine them with a very precisely crafted electrical field. I'm sure creating them won't be a problem with your tech. Now, be sure to tune the electromagnetic field dynamically, as the black holes will grow when absorbing energy. They will evaporate if they absorb nothing, so you will need to "feed" them when they are not in use. Alternatively, depending on your tech, you can create the fabric on-the-fly when you need it, and let the shield evaporate when you're done. Microscopic black-holes evaporate way faster than big ones. [Hawking radiations](https://en.wikipedia.org/wiki/Hawking_radiation) will be the energy form the absorbed energy will be released into (basically heat). Make sure to radiate it away from what you wanted to protect. You can even redirect it to the assailant, but at a lower rate on average. Edit: Source of the idea to move a black hole [here](https://physics.stackexchange.com/questions/235816/is-there-a-way-to-move-a-black-hole). [Answer] **Energy-absorbing shields that allow use of the energy already exist** They are called solar panels. [Answer] The Langston Field can be discovered only by accident. No to be more serious: You want to have the shell of a soap bubble with certain properties. Any property you want to have applied in a shell of a bubble will likely need a material bubble. Then you can think of superconductors, high heat compressors, high efficiency solar panels, all in combination. If you handwave the physical shell, you can go on and handwave the entire physics just as far as you need it for your story. [Answer] **Plasma shields/windows** are currency being researched as a means of deflecting or containing various forms of energy/matter. One example is research into using a short sharp burst of intense plasma to deflect incoming attacks by high velocity projectiles (specifically those involving H.E.A.T. rounds). Plasma fields can also be configured to act as physical barriers to physical objects i.e. plasma windows which hypothetically would for instance could act as 'air locks' which allow physical objects to pass through while confining atmosphere on one side (so a sort of force field). It might even be possible (input from a physicist required) to design a plasma field that would absorb/deflect a specific frequency of radiation, say a laser frequency or a specific type of particle beam (based on the constituents of the plasma being used) at the cost of ignoring other frequencies. Your problem is creating one that would do everything i.e. defect ALL physical attacks and ALL frequencies of radiation from ALL directions at once - plasma shields/windows etc aren't 360 degree constructs. So as long as you are sticking to current physics in theory you create a device that would repulse or deflect a specific type of attack from one direction but not all types of attack form all directions. [Answer] As already suggested by another user, use solar panels but also [shock absorbers](https://en.m.wikipedia.org/wiki/Shock_absorber) In our universe force shields are made of solid matter....otherwise you have to use magic or change the meaning of words so that force shields mean something else. Regardless, if you combine polycarbonate or bulletproof glass together with solar panels and shock absorbers you have an "invisible" shield which can absorb both light and blows to transform them into usable energy, mostly heat. Here's a guy testing a polycarbonate shield, it's so clear that it's almost invisible and after many blows it remains almost perfectly clear.[video](https://youtu.be/YmRXqWuaG2c) Please stop using magical shields made of energy or whatever... Solid matter is cooler anyway... All matter matters. If you don't want the shield to be almost completely transparent, use led lights so it glows in the dark like some magical shield or something.... ]
[Question] [ I have a character (humanoid) that has the ability to breathe underwater; either through gills or through augmented lungs but I'm not sure what starting list I should be aware of in concerning their water they'd breathe. I know fresh and salt water is one issue but I'm sure each has their own set of problems but they're both still water (excuse pun there) and would no doubt have a lot in common nonetheless. I know for *us*, the air has to be specific in composition and free from toxins but we breathe in contaminants such as pollen and other gasses. I can estimate that water would also contain contaminates of pollution and plants, but given it's much denser than air, it'll carry a lot more and suspended too which would no doubt affect the characters' ability to breathe in something 'clean' There's also no doubt a ton of marine life; especially on the microscopic level, plants too, chemicals... but I'm not sure on how that'll impact a humanoid's ability to breath or how they can filter some of that out if they're physiology is more...augmented from a human. So, my question is for my water-breathers, What should I keep in mind *specifically* before they jump into a random puddle of water and how it would affect them? [Answer] Stirring up silt and fine particles from the bottom. Not only impacts visibility, but could be detrimental to the lungs and gills. The amount of dissolved oxygen that is availible is also potentially a problem. Especially in still waters it could be pretty low. In fact, it is probably a lot lower than the availible oxygen in air. So the Metabolic efficiency may need to be pretty different. Apparently, from what looks to be a old dead website, [here](http://web.utk.edu/%7Erstrange/wfs556/html-content/02-metab.html): > > Water has relatively little DO (<14 mg/L) compared to the oxygen (240 mg/L) in air, so fish must be efficient in getting it. One factor that contributes to this efficiency is the unidirectional flow of water through their gills. Terrestrial animals have bidirectional flow (in and out of the same tube, the trachea) which is inefficient in that fresh inspired air mixes with stale expired air. With unidirectional flow, there is no mixing. Another factor is the countercurrent movement of blood and water. At the lamellae, blood flows one way and water the other, which insures that maximum gas exchange will occur. If water and blood moved parallel with one another there would be less gas exchange. > > > And build of up carbon dioxide in the water can be an issue: > > Carbon dioxide is much more soluble in water than oxygen so blood can hold the amount produced with very little increase in partial pressure. That means that there is a very small pressure gradient between blood and water to push it out of the body. In order to rid themselves of carbon dioxide, fish use some physiological tricks including the use of carbonic anhydrase. Despite this low gradient between blood and water, fish in nature have little problem moving carbon dioxide out of their bodies. > > > [Answer] Heavy metals, for the very reason eating too much fish can kill you, breathing heavy metals through your gills is a bad Idea. And the entire planet is polluted. Also the sea is filled with nasty parasitic insects which attach to the gills of various fish or their tongues. But I guess having an insect injecting you with pain killers so it can eat your tongue and gills can be dealt with if one pays attention to always bring a medical kit with themselves. But it could be kind of like crossing the road, if you pay attention 99.9% of the time...it still takes just 1 single car crash to kill you. One could touch their gills and tongue continuously, but eventually in a lifetime, it will happen at least once that they get distracted and a bug eats their tongue and gills. We can survive in really polluted areas because our noses are filled with hairs and mucus which filters the air. If you blow your nose after a walk in Rome you will notice your mucus being black and not colorless. Thanks to our filtering system in the nose, pollution does not kill us right away, maybe it decreases our lifespan by a few years. So your water breathing people need a similar filtering system for their gills. ]
[Question] [ Say I have a race of obligate carnivores (for simplicity, we'll say they're felinoid). They have carnivore dentition, and *must* eat meat as a major component of their diet, but they can also eat fruit and derive nutrition from it. They *enjoy* fruit (and vegetables), but for the complex flavor and tartness rather than for sweetness, which they cannot taste. (They react to fats much the way humans react to sugars. My theory is that they can break down simple sugars, but not carbohydrates, they need lots of protein, and there is something present in meat that they cannot get from other sources short of artificial supplements; possibly [taurine](https://en.wikipedia.org/wiki/Taurine).) Now, obviously they aren't going to eat a *lot* of breads/grains, except maybe as a form of dieting, however there are all sorts of interesting culinary dishes that can't be made without grains ([Wellington](https://en.wikipedia.org/wiki/Beef_Wellington), burritos, fried chicken and so forth); in particular, grains give a certain "crunch" that's hard to replicate with pure animal products. Assuming that they've been exposed to these by other means (as they probably wouldn't invent cultivation of grain on their own), would they be able to eat such dishes? Or is there another way to make such dishes using only "meat" products or something else that is easier on their digestion? I'll assume, first, that they *want* to eat such dishes, and second, that they aren't *toxic*. (That is, they can eat citrus, onions, grapes, cocoa, etc. without being poisoned. Grains might not be wonderful for their digestion, however, but they're willing to put up with a little extra "bulk" moving through their systems for the sake of excellent gastronomy.) [Answer] **Yes** Still [using cats as an example](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5753635/), there is no issue using sugar and starch in food such as bread for energy and as a source for sugars. Even if the beast is an obligate carnivore, its metabolism will still be based around sugars and it will almost certainly retain the ability to use **free** sugars from diet instead of having to generate them all internally. The benefits are simply too large and availability of carbohydrates in diet too universal. Where being obligate carnivore does impact the diet in comparison to humans is that ability of cats to digest those carbohydrates is limited in quantity. If your diet generally contains relatively little carbohydrates, you do not need a high capacity to digest them. The surplus will simply get wasted. The excess would typically end up feeding bacteria, which may or may not cause issues. So small and occasional starch or sugar rich treats would totally work for obligate carnivores. As long as the quantity is small enough, there will be no issues. And even if you indulge too much, the consequences should not be worse than for humans, they'll just happen sooner at lower quantity. An obligate carnivore might have lost its ability to taste sweetness and actually prefer crunchy bread with lots of texture and dietary fiber to sweets. Note that while individuals cannot adapt to having more carbohydrates in their diet than they can digest, the species can. If your obligate carnivores have a diet with excess carbohydrates over several generations, the individuals with higher ability to digest them will have an evolutionary advantage and the typical capacity to digest carbohydrates will trend up. [Answer] Using cats as an analogue, since they meet the criteria of felid obligate carnivores, I'd say that they'd be capable of eating bread. A quick google image search is all that is needed to confirm this. [![enter image description here](https://i.stack.imgur.com/EigeBm.jpgx)](https://i.stack.imgur.com/EigeBm.jpgx) [Answer] You are correct that an obligate carnivore *must* eat meat (e.g. cats because they can't produce taurine), but that doesn't stop them from eating other foods, such as sugars and grains. Their sense of taste, their dentition, etc. are simply tuned by evolution to *prefer* foods they *need* to survive because those who don't would tend to die before passing on their bad genes. However, once their nutrition needs are met, e.g. a housecat with a reliable food supply that doesn't require hunting, they may eat all sorts of things that aren't nutritious because they're interesting (e.g. bugs, string) or assist with digestion (e.g. grass, bones). We humans put all sorts of weird stuff in pet food that they'd never eat in the wild, in some cases specifically because it *isn't* nutritious and we want to put them on a diet. Also, while many cats would prefer raw food if given the choice, others actually prefer canned or kibble, so it's not unreasonable for felinoids to have a more diverse diet than what biology dictates, and it may vary wildly by individual. There's just a floor to how much of it must be meat. Note that some felines *are* allergic to grains, but only in parts of the world where grains simply aren't found. Felines that are around grains in the wild *will* eat them occasionally, even if only second hand in the digestive track of their prey, so allergies were long ago removed from their gene pool. [Answer] **Yes** Bread contains little nutritional for cats, except for the sugar within it. Sugar itself isn't great for cats, especially given that they didn't evolve to deal with consuming large quantities of it, unlike omnivores such as *Homo Sapiens*. They also can't really digest plants. This is because their digestive system is too small. An obligate carnivore, such as a cat, will have a very short digestive system (specifically small intestine) because of how easy it is to break down meat. By contrast, an obligate herbivore, (such as, say, a koala) will have an incredibly long small intestine and very specializes enzymes. We humans, by the way, fall in between the two extremes. And bread is pretty delicious. Not only the taste, but the various textures of bread isn't something that you can replicate given only meat. The cats would certainly be capable of eating them. Would there be problems? Yes - cats weren't exactly designed to eat grain. Still, they're more than capable of developing a tolerance for it, and such a tolerance is pretty pervasive among species that live near wild grains. Even if it isn't, by using small and constant exposure, it's possible to build up a tolerance enough for eating bread. ]
[Question] [ I have recently learnt about the [flooding of the Nile](https://en.wikipedia.org/wiki/Flooding_of_the_Nile#Basin_irrigation) and the irrigation around it, enabling plentiful crops by depositing nutrient rich silt during bronze age Egypt. I have also learnt about [volcanic ash improving soil fertility](https://en.wikipedia.org/wiki/Volcanic_ash#Volcanic_ash_soils) as well. Is it conceivable that a fantasy empire could be built around this fertile soil? How would they survive the frequent eruptions that regenerate the fertility? [Answer] **Yes but not really.** *Volcanic soils can indeed be highly fertile. And floods of the Nile did indeed help keep the soils of the Nile Valley fertile. But that does not mean you want regular volcanic eruptions. Fertile volcanic soils and fertile river valleys are two different things.* **What did the floods do?** *They replenished the soils depleted of nutrients by agriculture and limited salinity caused by irrigation.* In the Nile valley this is very useful because the soils are brought by previous floods and have a structure that is not particularly suited to retaining its fertility. You can think of the soil as fine sand or clay or mud. This is obviously a simplification, especially in ancient times when extensive wet lands had accumulated highly fertile soils, but you can fairly say that the particular soils that had been farmed for centuries and were subject to floods had this issue. Similarly hot and dry climate and easy access to the Nile meant that extensive irrigation was used. And because of that same climate lots of water evaporated on the fields and left behind lots of salt in the soil. Salt in the soil reduces the ability of plants to draw water and nutrients and thus reduces fertility. The water from floods makes the excess salt dissolve and essentially resets the salinity back to a base "after flood" level. So floods in the Nile valley and Mesopotamia could be potentially very useful in replenishing fertility reduced by agriculture. **Why are volcanic soils different?** *The volcanic soil has different composition and structure and only coincidentally happen in river valleys so their agriculture tends to rely on rain water.* The structure of the soil is a big differentiator. The bubbling of gasses during the eruptions produces grains with large surface areas. This makes them suited for making concrete. It also makes them excellent places for nitrogen fixing soil bacteria to live in. And boosts their ability to retain nutrients or water. Not all volcanic soils are like this but these are the fertile volcanic soils we are talking about. This means that volcanic soils not only retain more nutrients, they can naturally recover the crucial nitrogen. In addition volcanic soils can be very thick and extensive. If the soil gets depleted, you can dig or mine more, you do not need to rely on new eruptions. You can boost this by spreading agricultural waste and ash from fires back to the fields which even "primitive" civilizations can do. This is effective in replenishing nutrients other than nitrogen. Fertile volcanic soils also often happen on sloped or elevated areas. This is simply because the process that creates them is additive and associated with a process that often creates mountains. This means that agriculture in volcanic soils often relies on either directly on rain water or at least on water that comes from rains relatively close by. Either case it will carry less dissolved salt than the Nile in Egypt. The climate is also generally not as hot and arid as in Egypt, which has after all essentially a desert climate. And the slopes and the composition of the soil mean the water does not pool and evaporate on the surface. These factors mean that accumulation of salt is much less of a problem than it was in the Nile valley or Mesopotamia. At least until pumps allow extensive use of ground water or water piped from more distant sources. There simply is neither the same rate of evaporation nor the same volume of salt carrying water to use. Abundant water would have to come from rain which does not cause a salinity issue. So there is no need to replenish the soil with new eruptions to control salinity. [Answer] > > Is it conceivable that a fantasy empire could be built around this fertile soil? How would they survive the frequent eruptions that regenerate the fertility? > > > It depends on the frequency of the eruptions. Look at Etna and Vesuvius, for example. They were known since ancient times for the fertility of their soils, boosted by the volcanic material deposited there. Latin authors prided the green sides of Vesuvius, covered in grapes producing a delicious wine. If the eruptions happen quite spaced in time, say once every hundreds or thousands years, they cause temporary havoc and then allow for settlements. If they instead happen more frequently, like with some Hawaiian volcanoes, there is no time for proper settlement as long as the volcano stays active. [Answer] **Stone mulch.** In 1740 a series of huge volcanic eruptions devastated the island of Lazarote in the Canary Islands. When the volcano settled down, the little rocks that had spewed out and landed on the ground hugely improved the fertility of the fields. [![enter image description here](https://i.stack.imgur.com/AlDsf.jpg)](https://i.stack.imgur.com/AlDsf.jpg) <http://www.harialanzarote.com/stone-mulching.html> > > FATHER Andres Curbelo, a priest in the small village of Yaiza in the > centre of Lanzarote, provided the only surviving chronicle of the > massive eruptions of the 1730s in a report to his bishop in Spain. He > described how “on the first day of September 1730, between nine and > ten at night, the earth suddenly opened; an enormous mountain emerged > from the ground with flames coming from its summit. It continued > burning for 19 days…Then a new abyss developed and an avalanche of > lava rushed down, running as fast as water, [before] a great rock > burst upwards with a thunderous sound and the pressure of the > explosion forced the lava to change direction, instantly destroying > two villages.” …The geological mayhem continued… > > > The few thousand > residents, a mixture of indigenous Berbers and Spanish colonists, were > in grave peril from the explosions and the lava flows and, so it > seemed, from famine. Their dry fields, which had once nurtured grasses > and meagre crops of grains, were now covered with a layer of black > volcanic stones. … As they returned to their wrecked fields across the > lowlands of central and southern Lanzarote, looking for anywhere with > soil that they could plant their crops in, they discovered something > odd. Parts of the island had indeed been obliterated, mostly by lava > flows. But in the areas that had become blackened fields of stone, the > crops had not died, and in many places they were bursting forth > between the stones with renewed vigour. > > > It didn't take the farmers > long to discover why. The black stones shade the soil from the glare > of the sun, reducing evaporation. Recent hydrological studies have > shown that they cut water loss by around 75 per cent compared with > uncovered soils. The pumice-like stones are porous and trap moisture, > but they also provide a sterile barrier or “mulch” that stops weeds > growing and makes ploughing unnecessary… … (F)ar from destroying the > island's agriculture, the stones – which the local people called picon > – were instead nurturing the crops… (T)he farmers began to dig small > holes through the picon to the soil beneath and to plant crops. They > diversified from their usual grains and grasses to fruit and > vegetables, having discovered that they too would now grow on the > island, provided there was a layer of picon at the surface. > > > The stones > revolutionised agriculture on Lanzarote… By 1776, an anonymous > chronicler was recording a “prodigious mutation” of farming on the > island. “Marvels abound, with the land being more fertile, becoming > fruitful and bearing fruit two or three times a year. Like sponges, > the picon soaks up the water, and the crops receive a delicate, gentle > watering,” he wrote. “Before the eruptions in 1730, the most the > island produced was bread and beef; now on the strength of the picon, > it produces grapevines, vegetables, maize, potatoes, pumpkins and > other produce.” > > > Original article from New Scientist; "The Miracle of the stones", Fred Pearce, Volume 191, Issue 2568, 9 September 2006, Pages 50-51. Full text free at above link. So too your land. The volcano spews out stones (bring the kids inside during the stone rain!) that shower the fields. The farmers rake them into organized plots. With the stones and naturally occurring dew, they do not need to irrigate. [Answer] People are burning down the Amazon forests to create fertile farm land to grow crops to feed cows to make burgers. So yeah a never ending fire can have its uses in a modern society as demonstrated by the Amazon fires continuing over the course of 20 years of man made deforestation. McDonald's and Burger King would benefit a lot from such volcanic activities. The same is happening in Australia but for similar yet different reason, they don't care about burgers they just want to boost the economy with agriculture... Most of Australia land is infertile. Humans have practiced arson for agricultural reasons for millenia. Also, if you think no human being would be stupid enough to settle and make farms near a volcano, then obviously you've never visited Italy. In Naples people literally live inside a volcano. ]