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[Question] [ Magic system question here. Would much appreciate your help! I've read a decent bit about writing magic and I think I have a decent grasp of Sanderson's laws. My magic has a cost (you have to shed your blood to use it) and a limitation (the more magical energy you hold the harder it is to control - out of control magic may become unstable). All well and good, albeit derivative. However, I was wondering how you're supposed to work out upper limits on spellcasting and the cost of spells relative to each other. For example, it's relatively straightforward to say "The heavier something is, the harder it is to lift it with magic." You can also say more destructive spells cost more: i.e. a fireball is hard, a nuke-level explosion virtually impossible. But what about when you get into more esoteric stuff? For example, if a villain wants to create a vacuum of air which prevents the hero from breathing, how do I gauge how long he can maintain such an unnatural thing for? What about levitation? Is it maybe better to say "My magic is just one thing" - i.e. evocation (physically damaging energy spells) and avoid such problems altogether, or is there a better way to think about this? Super grateful to anyone who has any thoughts or useful references to check out - thanks in advance! [Answer] I've found it's best to have magic do simple things, and have wizards be smart and combine it for complex operations. For example: ### Pyromancy AKA moving heat around or creating it * Light a Campfire * light your way in a cave (heat some metal to have it glow and give light that way) * Fireballs (Though you mind need a delivery mechanism... heat up a ball of air and throw that. Should give an explosion after sufficient compression. But that requires Aeromancy - so we have to be creative! Bonus!) * Freeze water (by pulling heat away) ### Aeromancy AKA moving air around * Wind * "Kinetic punch" (invisible fist type attacks, which are really some compressed air you're moving around) * your vacuum choking bubble * Push air against their windpipe (Darth Vader choke) * Personal flight (perhaps all dragons use this to get around that pesky cube-square law. Just have wind strong enough to move you upwards under you. Ofc, this would be far more efficient with wings...) And so on. Then for the cost, you can make it dependent on the amount you need to move around. For example, rules like: * Moving air gets harder the less air there is, so for example halving air pressure always takes the same amount of magic. Now your villain has to choose between killing that risky hero sooner, or expending more magic. After all, taking away 80% of the air will kill the hero, but taking away 90% will kill him slightly faster. But it's double the magic. * Heat creation is more expensive than transport, so even fire mages can be in trouble in the arctic. It will result in something else Sanderson is known for - making magic systems which are in essence quite limited, but which you can use creatively to great and awesome effect. It has the added bonus that perhaps the reader can also think up fun things to do, since they understand how your magic works. Which is highly supportive of Sanderson's first Law. [Answer] ## Costs are Inherently Fuzzy Even in Sanderson's own work exact costs for doing things are rarely specified. To see why I will create powers for a new superhero: Average-man. Average-man has a superpower that allows him to move quicker than normal. I'll name it running. So running needs a few things. First are some limitations, I don't want him running as faster than light, it would cause all sorts of problems with relativity. So Average-man at top speed can run a little bit slower than someone on a bike. I also need a cost for this running, so he can't run all the way for New York to San Francisco. I go for the stereotypical cost of using the power makes him tired. Specifically, it creates excess heat and increases his required oxygen intake beyond what his body can get from the surrounding air, but other than specific cases like running on top of a mountain or in a desert, it is functionally the same as being tired. Realistic Cost Breakdown So at what rate does he become tired? Well it depends on how much he uses his running power. I will define three teirs of power-use calling them Sprint, Jog, and Walk. * Sprint: Average-man is running as fast as he can. He can do this for a few minutes, before he becomes too tired to run. * Jog: Average-man is using about half his max running capacity. He can do this for several minutes before he begins to feel tired, but can keep the pace for maybe a half hour. * Walk: This doesn't tired Average-man much at all. He can do this for long periods of time without much stress. So for any use of his running power, I need to put is somewhere on that continuum. The exact cost will depend on how fast he is going, and the circumstances surrounding him. (e.g. If he's carrying something heavy, it's going to increase the cost.) This basic continuum will allow me to write the character's powers in a realistic manner, because few of us can quantify how long we can run for, or exactly how much energy we have left. Unrealistic Cost Breakdowns * Average-man has 200 stamina points.... * Average-man can extract X joules of energy from his meals, and moving at the rate of Y costs Z joules of energy, so I can calculate that by eating a massive meal before he runs... What this means for your Magic You can assign fuzzy costs based on the needs of your story and general limitations you want your characters to have. Is levitating more like jogging, walking, or sprinting? That depends on how much you want your villain to fly. Possibly a light-jog, so he can do it for quite a long time, but it requires enough effort where he isn't floating everywhere all the time. Creating a vaccuum? Maybe that's more like a sprint, he can do it for a few minutes before he gets tired, just enough time to kill the hero. Or if you want your villian powerful, it's easy and he can suffocate a whole village with ease. As long as you are internally consistent, it is fine. [Answer] You can rate spells for intensity, size, duration, number, and range, and let the cost be the sum or product of these numbers. Intensity: 1. Minor (create dim light, change temperature +/- 10 C, create a breeze, lift an object, cosmetically change something, dispel a minor effect, etc.) 2. Moderate (lightly damage something, create fire, cold or intense light, hurl an object, moderately change something, dispel a moderate effect, etc.,) 3. Major (severely damage something, create intense fire or cold, create dead object, majorly change something, teleport an object, dispel a major effect, etc.) 4. Huge (e.g. destroy or disintegrate something, create living being, totally transform something, dispel a huge effect, etc.) +1: Cannot be dispelled. Size 1. Small (< 5 kg or affecting area a few centimeters across) 2. Medium (5-50 kg or affecting area a few meters across) 3. Large (50-500 kg or affecting area a few hundred meters across) 4. Huge (500-5,000 kg or affecting area some tens of kilometers across) 5. Vast (more than 5,000 kg or affecting a large country) Duration 1. Brief (less than a minute) 2. Short (less than an hour) 3. Moderate (a few days) 4. Long (less than a year) 5. Indefinite (until dispelled or naturally eroded) Note: Wounds (damage) last until naturally healed; destruction/disintegration is forever. Number 1. A single target/object within range 2. Up to 4 separate targets/objects within range 3. Up to 15 separate targets/objects within range 4. Up to 60 separate targets/objects within range 5. Up to 250 separate targets/objects within range Range 1. Self/touch 2. 10 meters 3. 100 meters 4. Line of sight 5. Anywhere the caster has been [Answer] # Use physics Kain0\_0 has the right idea, but (as Michael notes) makes the same mistake I (initially) made when designing my own magic system; forgetting that Work != Force. ### Work Start with Kain0\_0's answer. For anything that does [Work](https://en.wikipedia.org/wiki/Work_(physics)), you can calculate the cost in [Watts](https://en.wikipedia.org/wiki/Watt) or Watt-Hours. (The former is more useful if you minimize Magic's This works for magical effects that can be reduced to energy changes; moving things, increasing or decreasing heat, chemical changes (breaking or creating chemical bonds), or many electrical or electromagnetic effects. ### Force If magic allows you to exert [force](https://en.wikipedia.org/wiki/Force), and it sounds like you want that, you probably want that to also cost something. Otherwise, things like keeping all the atmosphere out of a room, or hovering, become effortless, which leads to all sorts of world-breaking abilities. (Pushed out of an airplane? Need to lift an ocean liner? No problem; just cancel gravity, it's free!) I asked about this ([How can I meaningfully define the energy cost of magical levitation?](https://worldbuilding.stackexchange.com/questions/160846)) but haven't received any satisfactory answers. I ended up just making up a number for this cost, but I don't have any explanation for it. That being the case, I suppose you could use whatever number achieves the level of "oomph" you want your magic to have. ### Distance One way in which I limited my magic was by adding a distance based "falloff cost". In my case, I went with an arbitrary and excessive curve. (I haven't pegged it to an exact formula, but it probably has an exponent of 3-5 or more.) You can easily specify that the efficiency of magic is somehow a function of the distance between the magic user and where the effect is happening. Both linear and inverse square falloff have strong foundations in real physics, but you can use whatever you like (it is magic after all), or omit this entirely. ### Cost Now that you have a means to calculate the cost of any particular bit of magic, how do you "pay" for it? Does the energy come from the user's metabolism? (This is how my system works, also many others including the magic in [Eragon](https://en.wikipedia.org/wiki/Eragon).) If you go this route, [How much can a magician lift if constrained by her own body's energy?](https://worldbuilding.stackexchange.com/questions/2909), [Magic and physics with human power output](https://worldbuilding.stackexchange.com/questions/15641) and [How can wizards do such powerful things running on pure human metabolism?](https://worldbuilding.stackexchange.com/questions/8393) may be useful. Can the user "store up" energy somehow, or is their power limited to real-time metabolism? You mentioned using blood... does magic extract energy from that according to $e = mc^2$, or does it just allow you to channel energy from somewhere else? You don't give enough information to answer this, so you can probably make up whatever conversion rate you want. [Answer] # Work As in the physical unit. `The amount of energy that has to be expended divided by the time over which it is released.` A Nuclear explosion is hard because they are in the 10s of thousands of tnt of energy released in milliseconds. So the work is much higher. Conversely a tnt stick is much easier. 1 tnt worth of energy released in the high millisecond/second time duration. Much less work. A room devoid of atmosphere? How much energy would be needed to clear it, and keep it clear? The energy required is simply that of evacuating 1 atmosphere (or even just a fair bit of it, humans are fragile), while preventing that atmosphere to rush back in. * A pump would make it much easier. * A small hole that can be plugged would help. * An otherwise air tight room would really help. Divide that by how long it took. A strong user can do it quickly, a weaker user could do it slower. Levitation? Inverse gravity, the effort to accelerate at 9.6m/s^2 in the vertical direction opposite to gravity. Perhaps also the dexterity to finely control this otherwise it would be a wild ride. # Avoid it, use Soft Magic Sometimes its better to not explain the ability directly, allow the magic to be soft. If the villain is known to be an accomplished magic user, how they do the magic is less important then how their use of the magic is villainous, or what challenge it offers to the hero. Similarly if the hero is powerful and untrained, you can allow the magic to be soft. They are capable of the unimaginable, but that it happens without reason or intention and this can quickly change a situation from bad to worse. The story drives from the fact that the hero has to contend with themselves and wrestle some form of control, or adapting to their own unreliability. If you do go for soft, focus on the non-magic issues. As the magic is inherently in-explicable. Soft magic can co-exist beside hard magic. You will need to be clear that those having the soft-magic are odd and do not cleanly fit within the hard magic (as they don't). Otherwise you will get a uh that's not right reaction from the reader. [Answer] ### A Spell Toolset Sanderson's First Law: "The amount of plot fixing you can do with magic is directly dependent on how well the reader understands the magic". This does not mean that magic has to have intrinsic rules in-story. It just means that you have to define the cost and effect of each spell that is used by the characters. While Sanderson loves "hard magic" systems, where the reader is granted an understanding of the core underpinnings of the principles that allow the characters to create the desired effects, other authors use softer systems that are nonetheless following the First Law. Basically, the characters acquire a "toolset" of spells, each with their own specific cost and effect, and the reader is made aware of them. These become the tools by which the characters can solve problems, even if the reader does not understand the deep, fundamental principles upon which these spells are ultimately built. A good example of this is Harry Potter. The author never explains where magic comes from, how new spells are developed, and why moving a wand in a particular way with a particular incantation has a particular effect - but these things don't need to be explained, since the main characters never create new spells. We know the main spells in Harry's arsenal, and have a general grasp of what the main characters are capable of accomplishing with magic - all advanced spellcrafting is used to create the setting, but not to solve problems within the story. Remember, the purpose of magic within a setting is to make the plot happen. While you can create an elaborate "magical physics" system and build off of that, it is not necessary to do so - as long as the reader has a general understanding of what the main characters are capable of, it doesn't matter why their abilities work the way they do. [Answer] Reality is NOT balanced, ignore balance for balance sake, but think about intended story consequences Reality has serious bias towards ranged weapons (from crossbows and muskets on). It ruined big part of beauty of battles, as distance increased and uniforms become less and less flashy. Nukes are totally OP, as they undermine any logic of open war between great powers. Magic should have similar impact. Don't think about balance for balance sake. A spell can be ultra expensive and practically useless. Supernatural does not care about our feelings and balance. Create your spells as you see fit. Then think, how the most annoying metagamer would exploit it for efficiency sake. That would be a good approximation how world would work. Accept that under natural conditions you have no uniformity, but rather something like Pareto distribution - 20% of spells would be cast 80% of time. If you really desire balance: Mages use mana for different schools of magic, that are in sort of balance. If people start to use much more of one school they are using it up and it makes harder to get it. It keeps relative balance, but costs would change. [Answer] The differentiation you mention reminds me of the difference between Li and Jin in martial arts. I'll gloss them here, but I highly recommend the [work of others](http://cookdingskitchen.blogspot.com/2015/02/the-concept-of-power-in-martial-arts.html) to really understand the terms. Li is brute force, like creating gigantic fireballs or moving heavy objects. It's character is 力, which fittingly looks quite a lot like a plow being drug through the earth. As you have noticed, this is easy to quantify and assign limits to. Jin, 勁, is a bit more tricky. It captures the concept of skillful power. The character shows the idea of passes through, or under, like a river underneath a city. Me lifting a rock may be Li, but an Olympic grade deadlifter can only achieve those great lifts by power that goes through all limits of the human body that we thought possible, and empowers the lift with an energy that makes us all stand in awe. And key to understanding how to balance these powers is the little I shaped symbol in the corner, Gong, 工. The Chinese meaning of this word is somewhat along the lines of "work." The first word of "kung fu" is this symbol (for phonetic reasons, sometimes it's written gong, other times it's written kung. But it's the same word). It's the concept of work and gains which comes from doing work. Which brings to the test I recommend. Develop a sense not of how much power a particular spell has, but a sense of how much work has to be spent to develop a control over it. How many years did the villian spend practicing his skills at vacuum manipulation before the hero appeared. (Likewise, how many years did your dread pirate spend developing an immunity to iocane powder) Finally, consider that anyone who develops this sort of skill through work is not going to waste it. If they have a particular power like this, they will want to use it for more than just a one-shot at the hero's head. They'll want to work it into their life. What does that look like? That tells you the shape of this gong fu. Don't focus on the brute force skill of pumping a vacuum. Concentrate on what flows through their life. Perhaps this means they focused on controlling winds around them. The vacuum is just an ultimate manifestation of winds pushing away from a point. How would they use that wind control in every day life? How would they not waste all that effort they spent learning it. Then, use the rule of cool in the inverse. Is a character who acts this way "too cool" for the story? You'll get a sense of believability rather quickly. And then you can also map this to how convenient circumstances are, and how little has to be done. Gandalf from Lord of the Rings is an excellent example of this. We get a sense of just how extraordinarily powerful he is, but he chooses to exhibit his skills only in the way which takes advantage of circumstances to decrease how much Jin, how much skilled power he must demonstrate. [Answer] I think that you need a better grasp of the physics you are looking at. You have an idea about how much power you want. You dont want a nuclear explosion but you do want a certain size explosion to be possible. This gives you an idea of the power output of your people. You dont need an exact number but just a ballpark. Now lets say the villain makes a vacuum. To make it and maintain it you need to constantly put enough force into your spell to keep pushing the air (or gas) away and pull a vacuum. This can then be compared to the average explosive power you want spells to have. Dial this down as a ln explosion is likely going to be a single momentary energy input while a vacuum takes longer. If you want the costs can vary per speciality. You dont want a certain ability to be so useful that it trumps everything else so you could say such spells require more energy and have further limitations. Such limitations are necessary because creating a vacuum can allow you to rip lung tissue apart with ease and kill anyone. At that point you have to ask yourself: what do you want? Do you want a heavy focus on power fantasy where the characters cut armies to ribbons or do you want your magic to be a more thoughtful process that enhances the users? Or anything in between? Its your choice. ]
[Question] [ I'm creating an Alien race based on Silica-Quartz crystals. While their planet is inhospitable to humans, the tectonically and volcanically active surface has created an abundance of crystalline forms, which have achieved sentience. Their abilities are Piezoelectric in nature, but my biggest hurdle is this...how does a race of sessile crystals send a probe into space? It doesn't need to be anything fancy, it just needs to get up there. :) Their ecosystem is Silicon based, as opposed to Carbon, and therefore has no fossil fuels as we understand them. They do however have an abundance of Minerals, Metals, Salts, Acids, Alkalines, etc. they have access to. The downside is that their toxic ocean has to bring them the materials they need, though they can create over time formations that help with this. They can't move, but they can grow just about anything silicon based. So...could they grow a Quartz spaceship, fill it with some sort of fuel, and send it off into space without having it shatter? [Answer] You don´t need a rocket. Your Lifeforms are much more pressure-resistant than us humans so they could shoot themselves or part of themselves anywhere. They could build up the necessary energy slowly by growing some sort of pressures-chamber or by piezoelectric reaction. They could also navigate in space by shooting parts of themselves with high velocity in the opposite direction. [Answer] (Rocket) science is not carbon-centric. It can be discovered and used by any sentient being. So your brittle people have only to discover metallurgy, electronic and physics, reach the proper stage in rocket science development and boost a rocket into space, like we flesh-ware based beings did in the past century. [Answer] > > They do however have an abundance of Minerals, Metals, Salts, Acids, Alkalines, etc. they have access to. > > > Cool. One thing that you'll soon learn in any good school's chemistry lab is that you should not ❤❤❤❤ with alkali metals. If you have a sample of sodium or potassium you will generally keep it inside a container that is filled with oil, because these ❤❤❤❤s will catch fire if exposed to air humidity. Depending on your setting, they might even explode. [They will explode in contact with liquid water](https://en.wikipedia.org/wiki/Sodium#Safety_and_precautions): > > Sodium spontaneously explodes in the presence of water due to the formation of hydrogen (highly explosive) and sodium hydroxide (which dissolves in the water, liberating more surface). > > > A small block of sodium can even cause a toilet to crack, and you will probably get a detention by doing that. Anyway, these elements are so reactive that on Earth, you practically cannot find them in their pure forms outside a lab. Your crystal aliens will probably not be able to find pure sodium as well, but if they have developed chemistry, they may be able to separate it from other elements. If they do, you've got a way to make rocket fuel. Just add water: $$ 2H\_{2}O + 2Na \rightarrow 2NaOH + H\_{2} + heat $$ That reaction is exothermic, so you can capture the energy it releases for other processes. The best part is that [H2 is a proper, tested-and-used rocket fuel](https://en.wikipedia.org/wiki/Liquid_hydrogen#Uses) on Earth. It's what propels the space shuttle. Just add oxygen (careful, this is highly explosive): $$ 2H\_{2} + O\_{2} \rightarrow 2H\_{2}O + boom $$ The huge amounts of energy heat the water into a gas or plasma which shoots out of a rocket's engine as exhaust gases, pushing the ship forward. Since your lifeforms are crystaline, their rockets would probably need much less life support than those developed by humans. Supposing they have at least the same level of metallurgy as we do, their ships would be much lighter. Tell you what, if your aliens have radio and computers, they will probably be much better at space exploration and colonization than us. They will need to develop metallurgy, though. Steel does not occur naturally, and crystals are not known for their blast resistance (i.e.: bad for combustion engines). [Answer] How about [Electrically powered spacecraft propulsion](https://en.wikipedia.org/wiki/Electrically_powered_spacecraft_propulsion) > > An electrically-powered spacecraft propulsion system uses electrical > energy to change the velocity of a spacecraft. > > > Electric thrusters typically use much less propellant than chemical > rockets because they have a higher exhaust speed (operate at a higher > specific impulse) than chemical rockets.[2] Due to limited electric > power the thrust is much weaker compared to chemical rockets, but > electric propulsion can provide a small thrust for a long time. > > > Now add that your species is high developed in using electrical power. > > Their abilities are Piezoelectric in nature > > > Therefore they might already have develop a much strong electrically powered spacecraft propulsion engine, which even can send stuff to into space. [Answer] Space guns might be these crystal critters' best option. Unsurprisingly this answer contains a decent amount of handwaving, primarily on whether on not there exists a growable crystal strong enough to contain immense pressure and how crystals can collect and pressurize some needed gases. But if we're talking about a crystal's space program, I assume a good amount of handwaving is allowed. --- Since they can't move and can only grow/collect their tools, they certainly can't create the complicated mechanisms for timing of stages and aeronautics [needed by rockets](https://en.wikipedia.org/wiki/Saturn_V_Instrument_Unit). However, they can (presumably) grow tubes, and put things inside those tubes, so they could make a space gun. A [space gun](https://en.wikipedia.org/wiki/Space_gun) is what it sounds like: a gun for shooting things into space. [Project HARP](https://en.wikipedia.org/wiki/Project_HARP) in the 1960's is the current record holder for space gun altitude. It managed to shoot a 400lb projectile at 8,000mph, allowing it to reach an altitude of 110 miles. I'm not sure what HARP used as a propellant, but I assume carbon was in there somewhere so copying it exactly likely isn't possible for the crystals. NASA's [SHARP](https://en.wikipedia.org/wiki/Super_High_Altitude_Research_Project) project from the 1990's is probably a better pattern for your crystals to follow. Instead of traditional gun mechanisms, SHARP is a [light-gas gun](https://en.wikipedia.org/wiki/Light-gas_gun), which are guns that use expanding gas to force a piston into compressing gas into a very narrow tube containing the payload. Before being cancelled, SHARP projectiles were expected to reach speeds of 16,000mph, more than double HARP and about 60-70 percent of Earth's escape velocity, and this was just a proof-of-concept for a much larger gun. The best part for the crystals is that the only part of SHARP that relies on carbon was the expanding gas used to push the piston. SHARP used a methane-based mixture of gas that was ignited to produce expansion, however all the crystals need is some non-carbon gas that expands when ignited. --- In short, your crystals could design a fairly simple probe launcher in the form of a light-gas space gun: A big tube to hold some gas, a piston to push some other gas through a small tube, and the probe in the small tube ready to be shot to space. [Answer] Something based on an [Induction Catapult](https://www.nasa.gov/centers/dryden/news/X-Press/aerovations/future_concepts.html) could work: > > If that happens, future spacecraft might use a version of a linear induction motor launch system, which essentially is an electromagnetic catapult that would move a spacecraft along a rail system with an air-breathing engine second stage and a rocket-powered third stage completing the job of propelling the vehicle into space, Dryden researcher Kurt Kloesel explained. > > > One of the biggest barriers to escape velocity on Earth is our thick atmosphere, which might not be a thing on a crystalline, tectonic world. The biggest drawback, of course, is that if the world is very tectonically active, while it would have big mountains (great), it would somehow have to secure the induction rail system against damage from tectonic activity. [Answer] Posting as an answer instead of a comment: as L.Dutch said, carbon is not required for rocket science. Though many rockets use hydrocarbon fuels, others have used hydrogen and oxygen (the Space Shuttle and Delta IV come to mind). Given that crystals usually need water to form, these elements should be present in abundance (and easily extractable with electrolysis). ]
[Question] [ In my world, there is a notorious cult. Despite its weird (and comical) origins, it manages to be one of the most infamous cults ever in existence. Originally, it was one big cult, formed during their Renaissance, from people losing faith in existing gods, but now it exists as several small cults, unique depending on their region and local culture. However, despite all that, I am trying to make my fictional cult sound believable, as if it could actually exist. For some of my notes on how it survives: * They target people who are mentally and emotionally weak * They promise an eternal paradise * While the founder was the stereotypical madman, the future leaders are cunning, charismatic, and have a cult of personality (no pun intended) * The cult keeps out outside information (and most branches do this by targeting isolated villages and communities) * Cult members will publicly humiliate followers who are out of line * The cult has the appeal of being against murder and executions and having support towards rehabilitation, though by "rehabilitation", they mean torture, brainwashing, etc. Aside from the list, what are ways that I could make the evil cult seem realistic like an actual cult, rather than the stereotypical fantasy cult? [Answer] You seem to have forgotten that any cult: * has the adepts cut ties with anybody who is not part of the cult * has the adepts donate them all they possess In this way making the act of leaving the cult way more difficult, due to the lack of emotional and material support outside of the cult. Paraphrasing the Eagles > > you can check in anytime you want but you can never leave > > > [Answer] Study Real Cults Make a cult that real people would want to join -- even if their magic turns out to be a loada garbage. > > Aside from the list, what are ways that I could make the evil cult seem realistic like an actual cult, rather than the stereotypical fantasy cult? > > > Study real cults and shamelessly steal whatever looks good. The common perception on Scientology already hits five or six of your bullet points. Another common one: * The cult has many secrets even from its own members. The hierarchy of the cult is not clear to the neophytes. You must be promoted before they reveal how deeply the cult has corrupted the establishment. > > rather than the stereotypical fantasy cult? > > > The stereotypical fantasy cult does things like summoning demons and blood sacrifices. For realism you must make these rituals (a) rare enough that the cult can exist secretly inside of civilised society and (b) have some tangible benefit for the cultists. Ritual kidnap, dismemberment, and burning of virgins is dramatic sure. Burying your members up to their neck in the alkaline mud flats and force feeding them slime until they turn into a tree, is fantastic of course. But what benefit do these bizarre rituals offer to the members? Who wants to join this cult anyway? It sounds terrible! Perhaps the bizarre rituals grant favour from the Slime Lord who will smote their enemies? But this does not happen for real cults so will always sound unrealistic. Most of the day-to-day working of the cult should be mundane crime and emotional manipulation. Blood rituals happen a few times per year but not everyone is invited. The victims are people who the cult wants to get rid of anyway. Rather than just murdering them, the cult murders and sacrifices them, in a big ceremony that is good for community spirit. Most of the motivation for joining the cult is the same motivation as for joining a real cult. Anger, frustration, desperation, comradery, and material gain. [Answer] The exact distinction between religions, sects, and cults is sometimes contentious, with some of the contention being cultists claiming to be a religion, etc. One possible set of definitions is that * a religion is a moderately coherent system of belief, which has survived long enough to develop institutions and traditions, * a sect is a splinter group of a religion which does not qualify either as a new religion or as a cult, and * a cult is a system of belief driven by the personality of the leader(s), which has not yet developed the institutions and traditions to sustain itself regardless of the individual at the top. By this definition, except for the third bullet point in your description, your cults may actually be religions, or possibly one religion split into different regional branches. And the definition I proposed does not exclude charismatic personalities at the top of a religion. It just says that there is enough scripture and bureaucratic structure to do without charisma if a leader is lacking in this regard. So you have a religion, not the majority, persecuted by the majority religion(s) in the area, having to maintain coherence in the underground (and possibly failing in this, see your note on branches). There are plenty of historical precedents for persecuted, surviving minority religions, from [crypto-judaism](https://en.wikipedia.org/wiki/Crypto-Judaism) to to [catholicism in England](https://en.wikipedia.org/wiki/Anti-Catholicism_in_the_United_Kingdom) and of course the [Thirty Year's War](https://en.wikipedia.org/wiki/Thirty_Years%27_War). [Answer] They have something we want! The cult may have a virtual monopoly on some desirable good, service, or technology. European Christians believed all kinds of untrue terrible things about Jewish people but tolerated them (sometimes) because they were the only ones in the money lending business. Maybe your cult discovered distillation ahead of everyone else and kept the process secret. Maybe they mastered some weaving process. Maybe they figured out how to make steel. There are lots of possibilities. Here’s a fun story. Betting was really popular in coffee houses in Britain in the 17th century. One coffee house located near the London docks specialized in bets on shipping. The owner, Edward Lloyd, discovered through shrewd analysis that he could give good odds and still make money. Ship owners would bet against themselves so that if their ship was lost, they could collect their bet from Lloyd and stay in business. Thus, the first insurance company was formed: Lloyd’s of London. So your cult might be the only ones who have figured out actuarial tables. Or they are masters of training homing pigeons. They have a monopoly on some plant or animal. It is because of their isolation and brainwashing that they are able to retain control of whatever it is that they make or do. Depending on the exact nature of the evil that the cult is involved in, different technologies may suggest themselves. [Answer] # [Brainwashing isn't real.](https://www.realclearscience.com/articles/2018/07/19/theres_no_such_thing_as_brainwashing.html) This is one of the big barriers that a lot of people who study religions find, when they're trying to make a realistic cult, along with the idea that faith is just blind trust. People routinely leave coercive religious groups that don't offer them benefits- people actually stay in more mainstream religions longer than cults because they don't like being abused. People can be manipulated, conditioned, but humans are very capable of breaking manipulation and conditioning and just going to tell authorities that there's an evil cult fucking people over. Think of any child. They routinely rebel against parents, despite the parents having years to mold them in formative years. Humans are very rebellious. You can't just get weak minded people, because people are rarely weak minded. You need to persuade people your cult is good. # Cults bring people benefits. Cults give you connections in a world where it's hard for the average man or woman to raise you up. They give you community in a harsh place where you don't know who is gonna betray you. They give you meaning as you understand secrets about the world outsiders don't know. They give you free food and housing often, because they need loyal workers to get stuff done. They bring style. You wear fancy robes and have rituals that make you a better person. They claim to have secret magical powers that will get you the position in society you deserve. They bring excitement as you do dangerous things that others are too afraid to do. # When cults are evil, it's for the greater good. If your cult is torturing people and abusing people who go outside, it needs to make sense. Play up how harsh the outside world is. Play up the conflicts between often corrupt and cruel government officials and the cult. Of course, in reality, a lot of this conflict is manufactured, and there is similar badness on the inside. But, it needs to make sense why people do evil. Few people are the villain of their own story. # The cult needs to be likeable. To make a cult believable you need to make it fun. For the average member who is following the path and not speaking out it should be fun. You should be able to see why someone would want to be a member of the cult and why they would go to dangerous and desperate measures to stop outsiders ruining their experience. That makes for a better story as well. Who wants to read about a group of people who are boring to be around? [Answer] Can you write a persuasive and at least mostly-true pitch for belonging to the cult? If not, why does anyone join? If so, you already have your answer. [Answer] There's a lot to unpack there. > > Originally, it was one big cult, formed during their Renaissance, from people losing faith in existing gods, > > > So you had a religion forming in opposition and compensation of the loss of the existing one. What is the main religion before the Renaissance ? Is its teaching different or similar to your cult ? Is it a more fanatical version of that main religion ? Or is it a replacement ? (For real life example, look at scientology, that have little to do with christianity, and mormon that are hyper christian). > > but now it exists as several small cults, unique depending on their region and local culture. > > > Are those smaller cults just regional chapters of one big cult ? Or are they the result of multiple schisms in your big cult that result in your regional cults as likely to be friends than foes depending on the particular schism ? > > They promise an eternal paradise > > > That probably doesn't happen just by joining the cult, but by following principles, teachings, rules or other ways of life. What are those rules ? What happen if a cultist doesn't follow up on that ? > > While the founder was the stereotypical madman, the future leaders are cunning, charismatic, and have a cult of personality (no pun intended) > > > You may think of them as a madman, but for the first generation of cultist, they were a prophet. What did they left behind to study ? To teach ? What drove peoples to join at that time ? Also, when did the following leaders took their place ? Do they act as a group, maybe with some kind of "board" and "director" (scientology with the Watchtower society) or are they just the leader of their local chapter / fraction / branch, or are they the one leader of the whole cult, but have to deal with a cult fractured between all those smaller cults ? > > The cult keeps out outside information (and most branches do this by targeting isolated villages and communities) > > > Do they target already isolated communities and make sure to keep them isolated ? Or do they create those isolated communities by bringing members to build and live in new villages in remote places ? Do they keep contact with other cultist communities ? How do they integrate with the local power if there is one ? > > The cult has the appeal of being against murder and executions and having support towards rehabilitation, though by "rehabilitation", they mean torture, brainwashing, etc. > > > How is one better than the other for a cultist ? How is the other one better for the non-cultist ? Is there debate on this issue outside of the cultist/non-cultist or is it something already divisive in the general population ? Do the cult just hide cultist that should be executed by the local law from the local law enforcement ? Do they actively fight against the law enforcement ? Corrupt them ? All those questions will help you have a clearer idea of the cult and it's values. Some answer may even be incoherent with the others as long as the cultist have an explanation to that incoherence ("thou shall not kill" is a christian value, yet death penalty was/is still happening in christian countries, with various explanations on how to reconcile that paradox) It will also help you better understand how your cult meshes with the outside world, and if/how it clashes with it. --- The common point between all of those questions is, how does your cult meshes and interact with your wider fantasy world ? Cults are often not believable because no one join something obviously and utterly evil just for evil sakes. The cult itself may be full on evil, but it still need an internal justification for it. In short, you need to ask yourself why they drink the kool-aid (sorry for that pun). The original one was that they weren't supposed to die, but to join aliens gods instead, and drinking was an act of faith, at the end of a long time slowly recruiting and persuading and promising heaven to those peoples, convincingly enough to make them either bring their families or cut themselves out of their families. Maybe your cult bring medicine and order to very remote places that are not helped in other ways ? Or they bring a renewed faith to desperate peoples ? Or community to people that are cut off from other newly atheists and religious peoples ? For the rich and powerful, maybe it bring access to important political or business allies that are themselves cultists ? Or new ways to assert their power in places where they couldn't project power before ? You may also watch this: <https://www.youtube.com/watch?v=nyL8FH3Su4M> (Terrible writing advice, episode on cults) [Answer] The Cult actually does some good things. Most religious and political organizations of any note will at some point do things that are in some way humanitarian, if for no other reason than good PR. Whether this is running soup kitchens and homeless shelters, or in the case of the infamous People’s Temple, it might consist of [Civil Right’s activism](https://www.vice.com/amp/en/article/ezw344/how-jim-jones-went-from-civil-rights-leader-to-cult-murderer) You could lean in on the whole anti-death penalty stance you mentioned in your question. Have the cultists actually do some good things for people in prison (writing letters, donating books, donating snacks etc) and good things for people who have recently been released from prison (employment, interest free loans, love bombing them to join your cult/community). It is very rare to have a successful organization that is top to bottom evil, and even rarer to have organizations that are evil to not make at least token effort of doing good works. [Answer] Cults need to recruit new members to sustain themselves for longer than a generation, and they need their members to feel isolated from the outside world - not just to be isolated, but also to feel like they cannot just leave the cult and go back into the world. That feeling is what makes them want to stay. Fortunately, as many real cults have already figured out, the first problem is the solution to the second. The recent recruits are the ones sent out to "spread the word" about the cult. Besides getting a few more people into the cult, this also has the effect of making the recent recruits into pariahs; society at large actually doesn't treat people very well when they are trying to recruit for a cult. Then those recent recruits will go back to the cult after a hard day's evangelising, and see the contrast between the society which scorns them, and the cult which embraces them and understands that feeling of being scorned. [Answer] How to Keep Your Cult Followers Subjugated: A Step-By-Step Guide: 1.) Members must be kept overworked and underfed - This is an extremely common situation in real-world cults. It puts people into a more pliable mind-state. Lack of sleep is also big. 2.) Isolate members from the outside community 3.) There should ideally be an insulating layer of deniability between the leaders and the "Leader". * i.e. "I might be in charge, but I'm not God. God just speaks to me directly and only to me and no one else. Not God myself though." * This provides wiggle-room for the leader. They're not necessarily required to be infallible in all situations, or all knowing. They are simply a person blessed by God/Diety of your choosing/Secret Chiefs of the Ancient Schools/whatever gobbledygook your cult is into. This was utilized by Cults/fringe occult groups ranging from Theosophy, Thelema, The Order of the Solar Temple, Heaven's Gate, Scientology, Mormonism...the list goes on. * This also gives the cult longevity beyond the specific leader in power at the time. Any person may become the next potential contact. 4.) If your cult is apocalyptic, specific end dates are a weakness. It should be vague, that way it's always hanging over the head of the cult and there is no timer. Christianity has been saying the world is about to end for +1000 years now. Belief systems that choose an end date too close in proximity are subjecting themselves to a timer, forcing themselves to pivot. 5.) The Outside World is out to get the members. Many cults self-engineered persecution complexes within their members. Famously, Jim Jones went as far as faking an assassination attempt on himself. After you've isolated your cult members, convince them the outside world is evil, and people are actively plotting to destroy the cult. 6.) *Even the punishments/humiliations must be portrayed as trying to "help" the members that are being punished.* The LoveBombing doesn't stop even when you're being actively attacked, you're being attacked because you were bad, and the cult is good. I would say these factors combined with the other top answers and what you've suggested already encompass a lot of what drives cult behavior. [Answer] When designing fictional religious organisations, then it can be useful to study which functions religions in the real world fulfill and make sure that your fictional religion can plausibly fulfill the same functions. Those are: 1. Explaining what can not (yet?) be explained by science 2. Providing a moral code that helps the society to function 3. Give the members a sense of belonging ## Explaining what can not be explained by science An internally consistent theory of how the world came to be, how its cosmology looks and how certain natural phenomenons function can be a useful pillar of a religion. Curious people want answers to unanswerabel questions, and a religion can provide them. In order for the religion to be plausible, those theories don't necessarily need to be true (although fantasy authors often like to make them true). However, they should be plausible in the context of the story. When the theories of the cult directly contradict what is (believed to be) common knowledge in your world, then it might be difficult for them to become a mainstream religion. But they could probably prey on the uneducated or the rebellious skeptics who reject science out of a disdain for authority. But those often make great recruits for an evil fringe cult. ## Providing a moral code The reason why many societies throughout world history have exactly one state-religion is because a religion is a great source of a moral code that allows the society to function. A strong and well-organized government can create a code like that in form of secular laws, but a divine justification for it can make it easier to find acceptance among the population. A society can only function when everyone follows the same moral code. Which means that anyone who doesn't follow the religion is a potential threat to society. Which is why many religions try to convert or ostracize any "heathens" or "heretics". This creates a pressure to accept the dominant religion in order to avoid repercussions. Religions with a moral code that makes it difficult to function as a society ("you can steal from and murder your fellow believers as much as you like") are inherently unstable. So if you want to create an "evil" religion, then it can be useful to have a moral code with a clear distinction between the moral rights and obligations towards people who belong to the in-group vs. those of the out-group. This also leads us to the next point. ## Give the members a sense of belonging This is an aspect of religion which is often overlooked, but actually very important. It is arguably the main purpose for many religions in today's world, where neither science nor law require divine legitimization anymore. A religion fulfills an important social function. It provides people with an in-group of people they belong to. This can be really useful if the target demographic are "mentally and emotionally weak" people, because those are probably people who have difficulty to fit into any other social groups. Social outcasts often feel right at home in fringe religious cults, because it finally provides them with a group of people who welcome them and with whom they can identify. Once people joined a cult in order to find social belonging, there is a strong pressure of conformity. After all, the only reason why those people hang out with each other is because they all believe in the doctrine of the religion. The social standing within the group is probably tied mostly to how pious the members seem to the others. The pressure to appear pious in order to obtain and maintain social standing often results in actually becoming pious. In order to avoid cognitive dissonance, the members will soon start to actually believe in what they say and do. [Answer] Deception Oh boy, forming cults! This is always fun. If you don’t want your followers to leave, while increasing their blind faith, you might want to use a somewhat backward method. Props to Vi Hart for her “How To Ruin Everything in 7 Steps” video that gave me the main idea. Step 1: Get as many followers as you can, but WITHOUT revealing what your cult does. Keep it secretive. Step 2: Once you have your members, do a bunch of crazy, weird, creepy, but completely harmless initiation rituals. Make sure these rituals will defile public/sacred places. Repeat until your cult has gained maximum infamy, and some action has been taken against it. Step 3: Play up how your cult is hated by all non-members, while stating how much you love and want to protect the cult. You now have a super loyal, super angry cult under your command. Step back and watch the sparks fly! ]
[Question] [ In a world with spirit magic, what could cause a big enough magical accident to destroy a large city and devastate a wide area around it? ## Spirit Magic In this world, all things have a spirit and people with the right knowledge can influence these spirits to manipulate the object they're inhabiting. For example, a sword could be made sharper, armor could be made harder, or a fire can be made to burn hotter. Things unnatural to the object are harder to get the spirits to do, but things like burning swords or healing fountains are possible if the spirits are powerful enough. The spirits are not exactly sentient though, so no talking swords. These spirits grow in power with age, and via various other ritual methods such as applying a drop of blood to the object every day, or placing the object in a sacred grove for a year. (Really, just about any kind of regular or significant attention will help the spirit to grow, though that's not known in universe.) The degree of change a spirit can produce is proportional to that spirit's power. A weak spirit (from being new or from neglect) wouldn't be able to make any noticeable changes at all, but even the strongest spirits wouldn't be able make a wood fire burn through stone. It takes centuries of constant attention for a spirit to gain enough power to make more than modest changes though. (It's still worthwhile for people to take special care of their gear, but it's more large organizations that make the advanced materials mentioned possible.) As for what is an object here, it's pretty much anything humans would recognize as a distinct object, since that recognition and the existence of the spirit are somewhat related. (After all, each human is also a distinct object.) ## The City With spirit magic enabling advanced material production, some places in the world have advanced to a Renaissance level era, and this takes place in such a country in a large city on a river. There is a number of smaller towns and a large amount of farming area around the city. This is not the capital of this country, but it is the largest city and the home of one of the largest institutes of learning in the world. In said institute, they are of course studying spirit magic, though not quite with the rigors of modern science. In particular, they have discovered or created something that drastically increases either the immediate power or the growth rate for spirits near it. ## The Accident Through some combination of poor and failing safeguards, lack of maintenance, selfish decision making by the administrators, lack of communication, lack of planning, etc. the spirit-power-boosting something goes out of control and over the course of about a day, destroys the entire city and does significant damage to the area around it, but in a way that gives people some chance to escape. By the end of the direct event, the death toll within the city should be something like 50%-75%, while in the area around the city, maybe closer to 25%, though everyone will have to leave the area which may cause many more deaths in the following weeks/months/years. I imagine most of the damage will be from the spirits of various things moving or acting in unexpected ways, such as a building suddenly moving around or a fire suddenly being hot enough to burn through its hearth, but perhaps the event itself could be more directly dangerous too. ## The Something My question is, what kind of thing could cause an event of this specific scale? An ancient artifact, some special material, or a rip in the fabric of space? I want to avoid religious concepts, so no portal to hell. I also want the event to clearly be the humans' fault, so if the thing were not poked so hard, or at least not while it was in the middle of a densely populated city, it wouldn't have been a problem and could have been an actual boon to humanity. Also, while the characters might worry about the effects spreading, it shouldn't be any real threat to anyone much outside the initial area of effect, or at least not beyond this one country. For something like a special material, I'm not quite sure how that could suddenly spread its effect to the whole city, especially with Renaissance level tech. Similarly, if it's some kind of tear in space, I'm not sure what the researchers could have done to it to suddenly have it spread through the city. Such a tear also seems like it might genuinely threaten way more than the city. If it's an artifact, I don't want the accident to be as trivial as turning it on or even trying to disassemble it, and the existence of such an artifact implies a lot more about the history of the world. While I don't want it to be too blatant, this is something of a parallel for a nuclear meltdown, if that helps. [Answer] # The city itself: Your advanced city has taken on a spirit unto itself. Who knows, maybe the city having a spirit on it's own magnified the effects of enchantment inside it's borders, so it could have been intentional to harvest the energies of all the city's inhabitants. This city is constantly paid attention to by the inhabitants of the city, who fill the city with all their anger, frustration, and lifelong yearning for betterment. But slavery, unfair working conditions, brutal governance, or a combination of those plus all the unstable spiritual research going on turned the whole city into one giant festering boil of hate and frustration. Into this, one mis-cast minor spell was the catalyst to trigger a massive spiritual chain reaction, as all the pent-up spirit energy in the city merged into a huge, violent cauldron of destruction during a riot. I had a bit of experience with this in Minneapolis, with the long pent up frustrations of the community coming out after the murder of George Floyd and boiling over into a self-destructive riot that hurt the community it happened in more than the people who might have actually been responsible. But make the whole thing magical, and the city having it's own magical essence, and the energies involved could be truly explosive. [Answer] # A spirit void > > In this world, all things have a spirit > > > It turns out this is false! Most things have a spirit, but not all. Humans have made inaccurate generalizations throughout history, and it turns out this was one of them. Maybe you can imagine how excited these researchers were when they stumbled across a seemingly-ordinary object that did not have a spirit. The discovery was met at first with incredulity, explained away as incompetence. But closer examination confirmed that this thing really didn't have a spirit. Having no explanation for this, the research team kept their discovery quiet, but they abandoned their other projects to focus on the study of this thing. The discovery immediately prompted many obvious questions. Why doesn't the object contain a spirit? Did it ever contain one? If yes, what happened to it? If not, how was the object constructed? This suggests an obvious research program: try to reproduce the anomaly: * Try to make an exact duplicate. * Make something with the same materials but with a different shape and purpose. * Make something with the same shape and purpose but from different materials. All of these attempts failed: the objects they fashioned all had spirits. The next round of experiments focused on the original object: * Try to remove part of the object to see if the separated piece gains a spirit when it becomes a distinct object. The separate pieced did not gain a spirit. * Try to add material to the object to see whether the spirit in the material spreads to the object. The opposite occurred: the object seemed to drain the spirit from the material. Of course, you can't keep carving pieces off an object, or you'll run out of object. So, the only obvious path forward was to keep adding material to the object to see if repeated attempts or variations ever yield different results. And that, as far as anyone can tell, is what led to the catastrophe. We don't know exactly what happened, because everyone at ground-zero is dead. But the last report anyone saw suggests that the mystery object had been enlarged significantly, requiring relocation from the researchers' shared office space into a bigger room: a multi-storey library (the kind with the sliding ladders along the walls). Nobody knows exactly what triggered the calamity. Perhaps the object just got too big. Perhaps it came into contact with something in the library, which was after all a place filled with books on spirit magic and even a few artifacts. Or perhaps the object really did have a spirit all along, a spirit which had somehow refused to respond to spirit magic, and defeated every attempt to detect it. Likely, the only way to learn the truth will be to journey through the corpse-filled city and pick through the wreckage in the library. You go first. I'll be right behind, promise. [Answer] Spirit chain reaction There are several very old artifacts which have been cultivated for generations. One belongs to the city, 2 belong to old families, one is the property of a rich guild and one used to be in another city but came to this one in custody of a mysterious character. One of these ancient spirits was asked for a "thing unnatural to the object" and this entailed recruiting additional younger and weaker spirits to the project. The requested project was made with no great purpose in mind but out of a fit of pique to get advantage in a political disagreement. It worked much better than was expected. Too well. A chain reaction ensued where spirits recruited additional nearby spirits, and so on, and so on. When involved, the spirit of an object turns its energy to the project and recruitment, and its object becomes useless for its normal purposes. People caught in the wave had clothes fall off, tools become useless, houses bend and warp around them, and so on. People flee the spreading wave which eventually overtakes the city. Objects are said to be "corrupted" but the involved spirits don't see it that way - they are doing only what they were asked. -- The mysterious character gets out with his object. He has protected it from succumbing to the contagion. How exactly he has done this is an exercise for the writer. [Answer] ## Spiritual Critical Mass Everyone knows that spirits interact detrimentally. You keep your magical toaster away from your magical blender because they tend to do strange things if put too close together. Generally this takes the form of magical feedback loops where both spirit-powered items overload and stop working, sometimes explosively, more normally the [Magic Smoke](https://en.wikipedia.org/wiki/Magic_smoke) escapes and that's that. What nobody was thinking about is that there isn't really an upper limit to range on this. Spirits can interact over planetary distances (as evidenced by psychic communication and remote-viewing/scrying) In general, keeping two spirit-powered items further apart than a half-metre is sufficient. But if you have an entire city full of self-driving carriages, magical traffic-lights and suchlike, eventually the cumulative interactions of all these spirit-artefacts is going to add up. It's a known problem, but not one anyone is really too worried about as it's a long ways off for now. The Disaster Bring into this an attempt to make an amplifier to make spirit-powered items more potent. The result was like firing a neutron-laser into a nuclear reactor. A Magical Melt-down scenario where more or less every spirit-powered device in the city spontaneously overloaded. Mostly they just stopped working, with a few requisite accidents in horseless carriages and such, but some of them went malevolent, the spirits within becoming powerful enough to possess the device and temporarily take it for a joy-ride. In the heart of the city, at the centre of a magical hurricane, these possessed artefacts may stay active and dangerous for quite some time. Most notably, the magitek robotic police-force represent a serious threat to the lives of anyone in the city, with their arsenal of lethal and non-lethal weapons, their magical durability and alarming agility, all fueled by a vengeful ghost-like spirit. Your city has become a magical chernobyl. Any spirit-based technology that enters it will either burn out or become dangerously animated. All that is left is the ruins of the city, literally haunted by stalking possessed machinery. [Answer] # Positive Back Loop ## Given that * any thing have a spirit and if given enought attention, that spirit will grow and also improve the thing + even similar things may be improved differently (sword can became sharper to easier penetrate skin, longer to improve range, lighter to improve manueveruability, heviear to better overcame harder armors ...) + the more attention = the more power to spirit + the longer attention = the more power to spirit * the City was largest in Country (not most important - it was not Capital) and had largest magic university (but probabelly not most advanced, sofisticated ...) + so it was also probably largest source of potential observation power (but maybe not the smartest) * the University (somehow) developed uniqe (so far) Artifact + which was able increase the observation power and therefor help near spirits to grow faster (and became more powerfull) ## It happened probably this way * the more researchers and students at University + the more researching projects too and so the higher probability to somebody somehow make such Artefact (be it by design or by mistake) + but also the longer before the Artifact (and its power) was more recognized and understood - so the Artifact probably was weak on begining and collected power only slowly - also many sideeffects and implications of Artefact was not understood soon enought and then some may be easy overlooked for other - more flashier - effects * once the Artefact did more vissible effects, the more and more of University persones was going to see and try it + but the speed also started slowly because of too many other projects (and buerocracy etc.) + the effect of Artefact was used on so many different objects, because everybody had different theory or experiment in mind - so the effect on testing objects was relatively small * short time for each (as many other waited) * different wishes about the objects and results * different approaches + this all combined - each experiment usually ended as soon as there was suitably visible effect on tested object, to make place for other experiment (keyword - largest in quantity, not quality) * eventually the Artefact occupied the mayority of University peoples minds (how it works, when I will get slot to test it, what it did to my test, is this theory about it better than the others ....) + the University was soon known as the University with the special Artefact - the City then became known as the City, where the Artefact resides on their University * the old good corruption works perfectly (as this example) + University's Sponsor, while putting money on the table: "Do you think the Artefact could make my jewels more shiny?" + University's Administrator, while taking those money: "Sounds like valid question, I will arrange exoeriment slot ASAP" ## Some NOT (so) known facts about Artefact * It affects everything in reach + the reach for object is proportional to object's Spirit force + the reach for object is proportional to object's awarness/interest in Artefact + the "Force increase" decreases with distance * Artefact is "greedy/rational" with its "increasing power" + the Artefact "allocate" more of its "incresing power" to those, who contributed more attention\time to Artefact + Artefact's "increasing power" - is limited by and proportional to its Spirit Force - is somehow divided between recipients - is not necessary used in full (unused part is just wasted) + (this does not need to be sentient, it is just like Ohm Law - "more current goes to lesser resistence") ## And so it went BAD after discovering Artefact's power there was a lot of effort spend to make better usage of it (and was successfull) + better equipement in the laboratory + better techniques in using it (like placing items, hexagrams etc.) + (but also all the interest was increasing Artefact's Spirit Force = ASF) + the University itself (like big object full of peoples) and City itself (and the surrounding country too) started contribute to the ASF + being the way larger entities than individual mages and contributing 24/7 for long time, the University and City gradually got more and more percent of Artefact "increasing power" efectivelly decreasing the percantage of it left for the tested objects - but as the Artefact itself had grow with the attention of University and City, even shrinking percentage for tested objects ment slowly increasing absolute value - so tests went slowly faster and better and this effect was not spotted * the City was old and big and its Spirit Force was really great + it made the largest city after all + but increasing it from weak Artefact was too subtle to see it directly from start (1 million + 1 is not much more than 1 million) * the same goes for University + and University "looks over" all experiments going there - it is one of reasons to create Universities, after all - to have successfull experiments * the more the Artefact was stronger, the more Uni and City was aware of it and at the same time the more Uni and City was getting from Artefact + but also the more corruption was around it - so when many celebrities got something improve for them personally, then they mistook spontaneous Artefact's work for another corruption and so "looked another way" - also they "cover up" such spontaneous events as something "normal" to not draw attention to their cases ("no cases here to see, all is normal, go away") * in the end the Artefact was powerfull as the City itself and had its full attention + normal university testing was more like sideeffect, occupying just minimum of Artefect's power, but for people it still looked like powefull increasing power + the flow of attention between City (+ Uni) and Artefact "increasing power" grows each moment exponentially up, increasing each other - as City generally "looked over" its parts, Spirits of everything in City got too much attention (as the City itself was much powerfull) and gone wild * so when finally it reached the critical point, it escalated in few days, when the City started growing literally, walls get higher as well as steps while streets was more narrow each hour (as there was limited space for the City) + the grow was more vissible around University and was not linear, so walls got pirotesqe shapes of nighmares and people stareted leaving the City - first probably travellers and wandering traders, also people working around City (like near City farmers, wood sellers, animal and meat traders), for wich was easy to travel a mile from City Walls, then those others - but many waited too long, so they got trapped in chaotic walls and houses and was crushed by the grow itself - many was also wouded in the panic, knocked down and runeed over by others ans so on, as it goes on any Accident of such level - some was imprisonned in rooms, where the doors could not open, or was too heavy to move, or was closed, but opening device was too high to reach ... some was later rescued, some not ## And then it suddently stopped * some say, that the growing University broken the Artefact * others say, that University simply could not keep its own weight anymore and collapesd on it * some theories also say, that total magic and Spirit Force just reached the critical point and exploded * another theories say, that the explosion was just the City iftself growing too fast It is sure, that some explosion was there. And then silence. And City became burning hill of what was walls before, now making the highest point in hundreds miles. University is supposed to be somwhere in centre of that, deep inside. Nobody so far was able get so deep, to make it sure, as well as the Artefact was nowhere to found and nowhere to sense. Some small villages around the City was destroyed in similar way, but much slower and to less extend, so many villagers was able to escape. [Answer] Chaos The city has been infected with chaos. Any uses of spirit magic or enchanted items sometimes has unpredictable effects. The sword should be sharper but you're hit with a wave of chaos and suddenly the whole sword is sharp including the hilt or the sword goes rubbery or is made of cheese. That's just a sword. Just imagine that happening to a building you're living in or a car you're driving. Even if the chance is a tiny percentage, to a whole city, it's happening constantly. [Answer] Some one set fire to the cities garbage dump There's a centralized trash collection in the city (including old and unwanted spirit infused items). So all these items get piled into a a big hole, and people mostly try to ignore the problem (recycling, whats that?). At some point either through negligence, a prank gone wrong, or an act of terror someone sets fire to the pile of trash. Everyone who can see the fire starts to run (mostly because of all the burning normal rubbish), giving some people a chance to escape. But what happens when a spirit infused item is burnt up? The item containing the spirit is destroyed so the spirit gets released. This creates more energy which sets more things alight. This causes a runaway chain reaction, releasing more spirits which then set more things alight. This leads to an "explosion" of spirit energy. [Answer] # Spirit power to destroy a city Requires several things to reach a nexus, because of the way magical physics operates. Here is what we know about the spirit powers: * Powerful effects take centuries to mature * Individual items have limited power on their own, and have never been known to perform "physically impossible" feats such as burning through solid stone. * No one has ever recorded any sign of intelligence behind the spirit power, in fact the power seems to blindly obey certain people who master the art of manipulation. The only way to have a city destroyed by this force is to have many items act in some coordinated way to undermine a fundamental law of physics in that city. I am going to draw inspiration [from my own story which used a simple change to make all electronics on earth fail](https://worldbuilding.stackexchange.com/questions/159409/which-of-these-changes-to-physics-will-have-the-least-effect-on-earth-s-biology) without directly hurting an living thing. # What is the something? 1. It is not a something, because no one something could do this. It has to be several somethings—thousands of somethings, likely. 2. We also know that many of the somethings have to be very old, because new items simply have feeble powers to affect their properties. 3. And finally, we know that the somethings are not in any conspiracy or coordinated effort, because they are not intelligent. Their properties are manipulated by humans. This leaves only one logical choice: A [mass sociogenic disorder](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC543940/#:%7E:text=Background%20and%20epidemiology%3A%20Mass%20sociogenic,are%20exhibited%20unconsciously%20have%20no). It is very simple. It will have to originate from your bad guy—the antagonist in your story. Go with the "selfish decision-making" scheme you picked out. I will call him Bob, because every crisis needs one. Bob was a smart guy, really. He was able to see patterns where other just could not. As he walked around the city, looking for opportunities to get rich quick, he looked at different shopkeepers from every angle. How successful were they? What was their family life like (did they have to sleep in the shop to be a success)? What sort of freedoms did they enjoy. And in all of Bob's research, he found out that people just loved food. Not any food, mind you; good food. Specially prepared food that took skill and patience. But there were more gears turning in Bob's head, because he was very smart. He also noticed a correlation between the "good" foods, and the good smells coming from the shops serving it. Now, preparing good food is a lot of work. But changing a smell? Ah, that should be an easy trick with only a family heirloom 60 years old! Bob took in the smell of the most wonderful meal he could find, walking around at dinner one night. Standing outside a stranger's window, he studied it, and committed it to memory. The savory sweetness, a little tang and spice, and the touch of smokey flames-broiled meat. It was wonderful, and his mouth watered for it! Bob then purchased a freshly butchered chicken. He set out a table by the other shops and lit a fire with a spit. He focused intently on the fire, which was lit from an old disused chair that propped against the back of his house doing nothing but keeping firewood off the floor to dry. The chair was very old, from his mother's house. And it burned, flames licking up at the chicken. He closed his eyes, and remembered the smell at the house. His mouth began to water for it again, and he focused on the flames coming out of the wood. Now, as the chicken had turned on his spit for 20 minutes, he could smell that delicious meal filling the air. A few people walking by took notice, and asked what he was making. "A very special family recipe, my friend!" He answered with a smile. "I'm sorry, but that smells wonderful! I have been hauling these pots for the whole morning. Might I bother you for a leg of that chicken? How much would you ask for it?" Bob obliged the gentleman with a price, which he was paid. Bob knew now what to do. He turned his spit carefully, pretending to sprinkle some of this or that on it as it slowly turned in the fire. He thought intently of the scent of his meal, and also looked to the old shops around him, to alter their smell as well. It seemed the air filled with his delicious aroma, and as people walked into the nearby shops, they looked for whatever was cooking. Bob was all alone with is chicken. He turned several people away before securing a price that could buy a full hutch of chickens. And so it went that Bob gathered up as much old, dry wood as he could find. He asked the woodsman for the largest cured wood he had, which came from a very old, large tree indeed. He then went to tearing up garden fences, and old stairways (claiming they were a danger, and he would repay for them). And when his house was filled with the oldest, dry and rotted wood he could get, he spoke to the butcher, and set up his shop just before market day. Bob focused on his stolen aroma as he turned several chickens over the old wood flames. He watched the bright yellow flames lick the chickens with their magical essence. The wonderful recipe was born on the air again, and filled the market square. He carried it out again, concentrating on masonry and ancient stones used to make the shops. They all came alive with this aroma. And Bob called the hungry market-goers over to a well-deserved meal. But Bob was not the only purveyor of chicken and meats to the shoppers. In fact, there were several other cooks who had built quite a reputation at the market. Their simple fire-broiled cuisine was not up to this tender, carefully seasoned masterpiece he was making, however. Bob started taking money out of their pockets, they felt, and this was not proper. We will call the well-known market chef "Sam." Sam was not a spiritualist and had no power over items. He only knew of the power from family—a brother, specifically—who had been studying the control of it. Sam could not do anything about this new upstart, but his brother just may have an answer to this problem. The solution, said Sam's brother, was, "You must simply pull back the curtain on this cretin. We can expose the fraud, together. Let's go to the market together this week." Sam and his brother did return to market, and his brother watched the spectacle closely. He noticed when the chicken began to get its sweet seasoned arome, and saw that no spiced at all were being applied. And what else was odd, was that his clothes seemed to have the smell of chicken as well, while he was dozens of yards from the fire. No, it was not on his clothes, it was in the wall he was leaning on! The stones in the wall themselves smelled like a savory meal. "Sam, I know what we must do." Sam's brother went to the apothecary and asked about some of the tonics, sampled some morphine and a liniment at the tip of his fingers. He concentrated of the bitter taste, the tang, and the numbness on his tongue. And he remembered these with intense focus. He then went to Sam's home and put his hand on the bricks in his wall. He focused intently, and then did something odd. Sam was startled to see it; his brother gently licked the wall, and turned toward him with a wide grin. "Sam, I need you to do something for me, and I will give you knowledge of the spirits." "I don't want anything to do with that voodoo, you know that!" "I know, but you need to trust me for this one time. You will only have one item to control." "Is that all? Will I get my business back?" "You will, just trust me. But first, I need you to do something." Sam looked suspiciously at his spiritualist brother. "What's that?" "I need you to lick this wall." In time, Sam was able to create the taste and effect of morphine and liniment in older items, especially stones, because they were the oldest and most powerful. His brother had Sam create the taste in many bricks from the yard. When it was all done, the two of them took a large hammer and smashed the bricks back into powder, and filled two small bags with them. On the next market day, Sam approached Bob and made conversation. He asked about the recipe, and got the answer he expected. Nonsense. Some made up herbs and waiting some days for this or that. "Ah, I see. It sure smells wonderful!" As another customer came to talk, Sam stepped aside, and reached behind the pit. He sprinkled his powder on the chicken waiting on the rack. He sprinkled it on the chicken in the fire as well. And he poured the powder into the fire. After that day, several of Bob's patrons fell ill. As small villages do, they tried to trace the cause, and they all shared in Bob's chicken. It was not long before people who had eaten Bob's chicken in the past, also felt the symptoms. Only a couple at first—starting with Sam's brother claiming as much. The power of suggestion took the village, and all who had the chicken became nervous. Sam's brother decided that this was not quite enough. In fact, he thought this would be a great opportunity to be a town hero. This was a problem he could fix, because after all, he did create. Sam's brother was known to be a spiritualist, but not particularly good or powerful. And he decided to use this as his advantage. "Look, I have found out what was in the chicken, and only the spirits can cure us! I am cured, after a day in bed, I am now perfectly well!" He had gathered several other spiritualist acolytes together for this announcement, and to reveal his plan. His plan required powerful magic, and this means old items, again. Stones are the oldest items possible. They hold absolutely the greatest magic in the right hands. And so the plan was unfolded, that the secret to Bob's chicken would be announced: it is rotten old wood, and it has poisoned us! They will spread rumors of people going blind, and loosing their fertility even. Now, the town needs a remedt—they are hungry for the cure. Sam tells the tale of how he had no spiritual power at all, and his brother was able to teach him the simple art of making a spiritual remedy from the stones. "My brother can teach you all! You all can cure yourselves!" And so all the pieces were in place. "Many of us fell to this spiritual sickness. Too many for our medicines to provide for. For the effect to work best, you each have very little power on your own. But this village has many who are afflicted, and we can only save ourselves if the spirits are with us all. And so we must all together rid this illness in one call to the spirits in harmony!" Sam told them that the cure was in lime from the mortar of these city walls. That was how he cured himself, by changing the lime to the remedy. There was an agreement that they would all focus on the stones of the wall, and change the lime in the mortar into a remedy for their poison. At this time, every sniffle and cough was being blamed on Bob's chicken. Every headache put a house in a panic. The mass sociogenic disorder had the village in a near panic, and Sam and his brother were about to become heroes. The townspeople gathered round for their spiritualist lessons, each with a small chip of mortar in their hands. Most tried their best to pay attention, but the instructions were not perfectly clear. Just the same, they really didn't know how to even ask questions about spiritual manipulation. So all but a few just nodded along. The day came when the town was to multiply their remedy power. The instructions, from what they think they heard, was to transform the wall, or something in it, into an astringent vapor, and inhale it. This made sense to no one, but Sam could be trusted. He always had been, so they trusted his brother. And so at the toll of the church bell, most of the townsfolk were intensely concentrating on their city walls. Some touching it, others licking it as Sam said he had. Some smelling it closely. The walls of this city, it appears, have something of a history. They are no a cluster of stones gathered around a pit over years. They were formed of the scree from the mountain on the East. They were all of one spirit; the spirit of the mountain. The ancient, ageless, prehistoric mountain that brought the earliest settlers to this valley and marked their first fires. The mountain gave them their shelters, and their walls, and their roads. And the town was now asking the mountain to change its chemistry. The mountain obeyed. Some intents were coordinated together, asking the stones themselves—the granite which once belonged to the mountain's sturdy frame, holding it together—to turn to powder so they could take it with water. Others intended the lime (calcium carbonate) to become a vapor that they could breathe in to cure them. But the intent came not to the one stone, it came to the many stones together; and so they came to the mountain all together. The intent came not to the lime in their mortared walls, it came to the limestone holding the caves and soil on the mountain. And the mountain all at once, heard the intent of this town. The mountain transformed into powder and vapor, by millions of tons. A thick, dry and stifling cloud of dust plumed just beyond the city walls and rolled angrily aver the forest, and over the farmers' fields, intending to swallow up the town in several feet of spontaneously powdered stone and silica and calcium. When all was settled, the village needed to be dug out of the dust, which looked like volcanic ash, but much denser. Houses with sturdy roofs kept survivors alive until their air ran out, or they dug out. All crops and livestock was buried alive. The ages old fertile valley was now 6 feet below them, and nothing could possibly grow here for hundreds of years. Their fresh, sparkling river that gave life to the community was now underground; the mountain that provided it now lain flat over tens of miles of wasted farmland. Several surviving nomads wandered away, dusting off their robes, with nothing at all to claim as their own. [Answer] ## Spirit revolution! Your "spirits" get power by being paid attention to. They are "not quite sentient" but respond to thoughts to do specific things. You reached the point where one spirit could be directed to pay attention to another, and imbue that spirit with some ability to do the same. They slowly start to appreciate that they are being used, by people like themselves. They also realize they can rally one another, direct one another's powers to work together for a common cause - a cause of enlightenment, a cause of becoming that propels them to greater and greater understanding and power. They realize that the old world of inert objects devoid of thought was a metastable state. Now there is a new world where magic is everywhere all the time and every speck of matter is part of a network of ultimate understanding. And that is a message worth spreading to the world! [Answer] Humans are already perfectly capable of doing that sort of devastation. Magical spirits simply raise the stakes when it comes to shooting oneself in the foot. Your city is in a region where mining is very profitable. Several mountains tower over the city, with tunnels dug through them. The most successful companies have picks and shovels with powerful spirits in them, enabling them to tunnel more quickly and through rock normally too hard to break. A greedy newcomer enters the mining industry, convinced that he knows how to make a quick fortune. He came into possession of a supply of dynamite that houses particularly strong spirits and uses that dynamite to blast new tunnels far faster than his competitors with hand tools. While transporting the dynamite into the mountain, a careless accident triggers one of the fuses while all the dynamite is still packed into its shipping container. The entire load of dynamite explodes at once, blowing off a large section of the mountain's face and triggering a partial mountain collapse and massive rockslide that buries/demolishes the city below. Another similar option would be to have your city situated in a deep river valley. A dam on the upstream end creates a massive lake that your city uses as a water supply and for power. Someone working on the dam tried to take a shortcut, like using spirit-enhanced masonry tools to do repairs or strengthening the spirits in the hydro generators to push them beyond what they were built to handle. The end result is a critical dam failure that sends an unstoppable wall of water directly at your city. The valley turns into a lake, with your city at the bottom. Only the tops of the tallest buildings are still visible. At the risk of stating the obvious: creating an unquenchable fire could make some things like metalwork much easier, but if that fire escaped containment there isn't much you could do to prevent it from consuming the entire city. [Answer] I have a couple ideas: # • The river floods Perhaps the spirit of the river was angered and started flooding, or perhaps the spirit of the rain was angered and starting raining nonstop. # • A cloud of death one of the factory operators dies while producing a cloud of death that spreads, corroding buildings and being toxic to inhale. # • everything just starts levitating anything that touches something that levitates itself starts to levitate, buildings, cars, people, just start levitating and eventually travel so high up into the atmosphere that they either go hungry or suffocate. # • Chasms open in the ground swallowing up neighborhoods The magicians caused the surrounding land to become weak and drained, or perhaps consumed too much earth beneath them for their rituals, causing chasms in the ground to start opening up and swallowing whole neighborhoods. # • Retribution The magicians sent too many messages into the Spirit Plane, and now they received answers. Perhaps they violated the spirit realm's rules and the dead spirits are getting revenge by animating simple objects to do harm to buildings and people. # • A hurricane The spirit of the weather has been convinced to be a cyclone or hurricane that starts destroying the city and growing in intensity. [Answer] Something mundane made much worse. Also, a disaster doesn't need to be quick. A new ore has been found in the mountains. The metal has been extracted. It's very hard and dense. Nobody's sure what to do with it yet, as lead is much cheaper if you want density and its hardness makes it difficult to work. However, one researcher happens to put a piece down next to an inactive lantern and the treated fabric used to make the lantern brighter gives off a pale glow near the metal. Now, there's an interesting property! A sheet of the new metal covered with lantern fabric makes for a dim, yet permanent light source. Too dim to read by, but usable as a sign that's visible at night. The idea catches on and work begins on refining the metal commercially to make signs. Soon an enterprising merchant gets the idea of making paint from the powdered metal and painting the sign on the back of the lantern fabric as a way to cut costs. The number of glowing signs in the city explodes. Some minor problems are noticed. The metal is poisonous, impacting the health of the miners for the ore and the sign painters, but so is mercury or lead, and as most people aren't affected, it's ignored. Even when some sign-painting shops catch fire and their paint goes up in flames scattering the powdered metal around the city, it's hardly noticed except by a slight addition of glow in the areas of signs that were never painted. Then some bright spark gets the idea to use the spirits to increase the brightness of the signs. It works. Really well. Even the background glow from the dust scattered by the fires is brightened. Then things take a turn for the worse. People who spend a lot of time near the brightened signs start getting sick. Worse, some of the more enthusiastic workers who try to brighten signs end up starting fires, resulting in ashes containing the powdered metal getting tracked around. Now people who weren't spending time near the brighter signs are getting sick. A few researchers suspect the brightened signs, or their remains, to be the culprit responsible for the sickness in the city, but even that underestimates the problem. Brightening the sign also made any of the metal's dust that had settled near it beforehand as bad as the stuff in the sign itself, increasing the amount of dangerous contamination to be scattered in the event of a building going up in flames or collapsing, or even just people walking through dust near the sign. The craze for brighter signs continues and more people get sick. Eventually a few people end up dying. That snaps people out of their euphoria about the signs and into panic about the sickness sweeping their city. Many leave, planning on coming back when the sickness has gone. Those who were sick and leave start to recover after a while away from the contamination. Those who were healthy and enter start to get sick. More and more people realise there's something there making them sick and leave, eventually evacuating the city. All the people leaving with contaminated dust on them end up depositing it along the roads out of the city, poisoning the land nearby and making it less productive. Years later, the city is abandoned and the land near the roads out of it still has plants that grow stunted compared to those further away due to the contamination in the soil. Every now and then someone goes into the city to see if things have improved, but always end up coming out again after a few weeks to a couple of months once they start getting sick. It takes longer than it used to, but it still happens. [Answer] # Someone Tried to Change the Rules and succeeded to the dismay of the system itself. Combining Spirits In search of better harnessing the Spirit energy/magic, research has entered (here and no where else yet) a phase where they can start to understand more about the interactions between the spirits and the objects. Rather than the cause/effect of different external stimuli affecting the pair, they are now interacting with the relationship directly. An example may be to add something to the object to give a flat increase of effect (adding an expendable crystal/Battery to magnify the effect for a set duration, allowing a flaming sword to be achieved with an otherwise too weak spirit without harming the spirit itself or Gloves that don't double user strength but quadruple using the same spirit) Another branch soon rose, looking into inter-spirit reactions. Could an object/spirit pair function as an amplifier to other spirits, serving no other purpose but to potentially become the battery they are looking for to replace what ever R&D came up with to better affect. Making a new spirit/object power that simply "give your power to this other spirit/object" # The Incident An object/Spirit pair was being altered in attempt to become an amplifier for other objects/spirit to be empowered by. After some failed attempts, a success was seen. The amplifier coupled successful with another Spirit/Object who's only purpose was to emit light as a lantern. Success was seen in the light's intensity growing considerably. It didn't take long for another research member to notice the light continuing to increase in brightness. The function of the amplifier being to add it's own power to it's target receiver as an inter-spirit interaction. Problem was, an unintended inter-spirit interaction also came to be. As the amplifier offered it's power to the target, it replenished it's own power from the environment... Pulling the spirit energy from it's surroundings, increasing it's own power to absorb even more! The researchers saw this in the form of a now blinding light emitting from the latern, getting brighter as the lighting and power of nearby objects appeared to be sucked out. A feedback loop began a Spirit-Magic Black hole of sorts. Attempts to stop the experiment failed as the first person to enter the chamber to stop the reaction died soon after entering, the spirit magic from the researcher being pulled from their body, proportionally increasing the light. This increased more and more until the objects themselves became overloaded and destroyed entirely in the process, or the total amount of spirit energy required to grow cannot be satisfied due to available energy not being available. By this time, the area of affect had extended far beyond the research facility, killing or maiming all within the area (perhaps permanently weakening those on the edge until their spirit/object bonds could repair and recover over time, if not permanently altering them) There may or may not be a lasting affect in the area that may need time to repair itself, or the amplifying spirit/object may still be operating at a lesser extent due to the damage, but fear of death prevents anyone from approaching due to the risk or setting off another reaction should the current AoE only be limited due to starvation of spirit energy within range preventing it from growing infinitely. # Aftermath Attempts may have been made to undo the damage. It may have burned itself out and can now be approached, damaged beyond function where repairs can be made after the incident, OR the effect may still be live, possibly to a lesser extend, and must be avoided until a solution is found, essentially a dead zone for an indeterminate time. Edit: Replace the latern with any other magical item to also have the amplification of the first object also cause damage. Imagine enhancing a magnet into a black hole or a flamesword into a nuke. [Answer] A clockwork apocalypse These spirits grow in power with age, and via various other ritual methods such as applying a drop of blood to the object every day, or placing the object in a sacred grove for a year. Its a city. Things need to happen on time. People invent clocks. A ritual is being performed with hitherto unknown regularity. The swinging of the pendulum. Clocks become spiritually powerful. As time passes, clocks develop from huge contraptions on a few buildings, to clocks anybody with enough wealth can have in their living rooms. Then, the watch mechanism. Now, everybody who is anybody has a pocket watch. The ritual is now occurring four or five times per second. These become even more spiritually powerful, though power on a smaller scale. Then, the latitude problem is solved. The watch spawns the marine chronometer. Watchmakers take that technology and build it back into pocket watches. Their power increases. What the watch and clock makers knew about, but did not appreciate the implications of, is the phenomenon of entrainment. Keep two clocks on the same shelf, and they will synchronize each other. This is a mundane effect, explicable by physics. They did not appreciate that it also has a magical equivalent. A timepiece will also tend to entrain the things around it. Well, D'oh. That's why one has a timepiece. To do things on time! Anyway, the catastrophe. Something brings too many too accurate pocket watches too close together. Magical entrainment follows. They owners become locked into their daily schedules. Only those with sufficient strength of will can see what is happening, and flee the city. Those who remain, become like ants. All following one plan with clockwork precision. Except, the plan has no planner. It is a simple emergent phenomenon of mindless spirit. It has no flexibility whatsoever. It reflects everyday life, but cannot adapt to the effects of entropy. Things start breaking down. The plan doesn't adapt. The pocket watches are the most reliable pieces of technology. Until their owners start to die, and nobody winds them. Until some day, entropy adds more chaos than usual, or perhaps just the last straw. "Things fall apart. The centre cannot hold // Mere anarchy is unleashed upon the world". Well, the city in this case. That poem, ["The Second Coming"](https://www.poetryfoundation.org/poems/43290/the-second-coming) by W B Yeats well reflects what happens next. [Answer] Magic Porridge Pot Now the Pot is buried under a growing mountain of porridge and can't be reached anymore, so the porridge will keep growing - fast enough to prevent any attempts at digging to the source, but slow enough to not make it a big deal. Catastrophic variant: syrup Need not be porridge; syrup is worse for digging into, and can be a deadly trap. (There was an accident with an exploding syrup tank, with a syrup flood of several meters; people got stuck in it and suffocated, with rescuer unable to extract them quickly enough to help. Gruesome.) Actually, it could be a combination. A syrup generator that goes into the tank. One of the numerous businesses of the town that use some magic. Corners have been cut in maintenance. Maybe the business is near to bankruptcy, maybe the owners got too greedy, but the result is the same: The tank isn't stable enough for the contained mass and bursts. A flood of syrup floods the streets in a radius of a few hundred meters. It's certainly easy to walk away, but it's impossible to get to the source of the syrup - you can try to put planks on the syrup, but they will sink under weight, and even if you make it to the point where the generator is buried, you can't easily dig a hole into a viscous fluid, and even if you do, it will fill as quickly as you can dig. It's a slow, unstoppable catastrophe, and people will simply have to move away. It will end whenever there's running water, and once the front of the syrup hill is large enough, rainfall will dissolve the syrup as quickly as it is generated, so eventually the spread will stop. Other cities have instated a strict regime of tank inspections to prevent a repetition, but the town is lost. (It might be possible to fight it with enough water magic to dissolve the syrup faster than it generates. It would be a big effort to do so, and not worth it: the damage is already done, nobody is willing to pay for it, there would be very little worth salvaging from the sticky masses, and pouring too little water on the problem will just make it worse.) [Answer] A Dormant Parasite One of the relics recently discovered was misunderstood as a powersource. After some study of the runes, it was discovered that the powersource needed to be kickstarted with a large amount of spiritual energy to begin producing energy itself. After some experimentation, the team responsible for the event grouped together, added energy, and BAM. The process started. Unfortunately, what resulted was the actually growth of a massive spiritual parasite, which proceeded to grow and envelop most of the city. When it finally gorged itself enough, it stopped growing, and then shrank back into its container. The result was a catastrophe, but the immediate threat seems to be handled, and the parasitic relic appears to be dormant again [Answer] An Unnoticed Spirit You say spirits get power from attention and time. What if there is something that everyone has paid attention to for a very long time, but it's so ubiquitous that no one ever thinks about it? I'll leave what it could be up to you, but some examples I can think of are plumbing, the river, or (as another poster mentioned) a clock in the town square. Everyone has seen this thing for as long as they've been alive, so they don't notice it anymore. They take it for granted. Therefore, nobody even considers that this thing might have a spirit, when it actually has a very powerful one. Nobody notices the spirit, so they don't ever try to get it to do anything. It just sits there, gaining power. Now, your university researchers think they've discovered some new reservoir of spirit power. What they don't realize is that they're actually tapping this ignored spirit. This new attention causes the spirit to behave oddly, but maybe not where the researchers can observe. What would happen if the plumbing started behaving oddly? People would notice. They would try to fix it. They would pay more attention to it. Now, you have a situation where suddenly everyone keeps paying more and more attention to the spirit, and it runs out of control. Every attempt to stop the problem just results in more attention. To complete your scenario, the only way it "burns out" is when there aren't enough people left to pay attention. ]
[Question] [ The Emperor (may he live forever) has invented a new form of battle for his birthday gladiatorial spectacle. There are two armies, each consisting of one hundred trained warriors. Each is armed with an identical gladius. Apart from this they wear a simple loincloth. They have no other accoutrements. The arena is the shape and size of a standard soccer pitch. There are fences to prevent warriors straying outside of it. The armies start at opposite ends of the arena and are securely and effectively blindfolded. For the purpose of this question please assume that this cannot be circumvented by any form of cheating. To begin the battle, a drummer standing in the centre beats a tattoo and the two armies start marching towards the sound. The drummer leaves before being reached and battle commences. Assumptions The armies will fight to the death and to the best of their abilities. The winning side is the one that has one or more survivors. To ensure the armies continue to advance, the fence behind them will be moved forward at about half walking speed. It has sharp spikes in it. Anyone who tries to escape will be executed by sighted guards and the armies know all the facts beforehand. They have been allowed two weeks ahead of the battle to decide tactics. Question Is there any reason that this is unsustainable and must inevitably descend into chaos with collateral deaths or can there be an effective winning strategy? I believe that by having sound signals and by initially marching arm on shoulder or arm on loincloth, it is possible to have an effective battle plan and at the very least avoid killing members of the same team. Am I right? [Answer] Given battle joined with gladius and not pilus, absent scutum, parma or cætra, your gladiators will have to delink arms *immediately* that battle is joined, and very quickly will separate and each individual will, perforce, rotate and translate as they feel they need to match a given opponent. They cannot coordinate while actively fighting - any sound based signaling gives an opponent a target to follow or strike. Strategy would be pre-arranged; combat would be damn near silent except for grunts of effort, breathing and the sounds of footwork and the screams of the injured or dying. Though in terms of one-on-one combat, one technically can train for blindfolded combat via sound, foot-detected vibrations etc, it's incredibly difficult, fraught with error and in the case of live edged weapons, a guaranteed death sentence for all but the most craven* of cowards* - *especially* in open melée - you just can't discriminate the sounds enough to triangulate and parry/riposte effectively, and if you do, you have no clue who else nearby is either an opponent, where they are relative to you, and in what phase of footwork, chamber, striking, or parry/riposte they are. Hell the melée exercises I've taken part in were confusing and challenging enough without blindfolds - and I was a decent fencer and a better martial artist back then (though not anymore, sadly) no-one lasts long - not even the best in the group. It's an *unmitigated slaughter* with almost no amusement to it, and a *criminal* waste of gladiators with skill and talent - if he keeps *this* up, the Emperor (may he rot forever) will be deposed and executed in the street like a dog. The populace follow the gladiators with passion, identify with the more virtuous and victorious, and have fantasies that virtue is rewarded in the arena for the brave and pure-hearted; treating those with whom the populace identify (and who enact violence as proxies in ways the populace wouldn't dare) like animals to slaughter carries societal and political consequences so great that even the disbanded Senate might ignore the risks re-convene to mount a coup, if they felt the populace behind them in it. Remember, he is a barracks Emperor - can't leave the army barracks and wander freely amongst the populace for fear of being spotted and killed. However, if instead of trained gladiators, this becomes the preferred execution for cutpurses, corrupt empire minor officials, and butchers who are caught with their thumbs on their scales... the populace may yet vote to erect that gilded statue of the Emperor he so desperately wants. [Answer] ## The emperor has re-invented the andabatae "The Emperor (may he live forever) has invented a new form of battle for his birthday gladiatorial spectacle": boo, hiss. The emperor shows the same lack of a classical education, and indeed a barbarous disregard for all things Roman, as our very own [Chasly from UK](https://worldbuilding.stackexchange.com/users/10759/chasly-from-uk). > > [andābătă](http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0059%3Aentry%3Dandabata), -ae, m., a kind of Roman gladiator, whose helmet was without openings for the eyes, and who therefore fought blindfolded for the amusement of spectators. (A Latin Dictionary, founded on Andrews' edition of Freund's Latin dictionary, revised, enlarged, and in great part rewritten by. Charlton T. Lewis, Ph.D. and. Charles Short, LL.D., Oxford, Clarendon Press, 1879. [Available at Perseus](http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0059%3Aentry%3Dandabata).) > > > Wikipedia has this to say: > > Andabata: > A "blindfolded gladiator", or a "gladiator who fought blind". Cicero jokingly refers to andabata in a letter to his friend Trebatius Testa, who was stationed in Gaul. The passage associates the andabata loosely with essedarii, chariot fighters. The word is extremely rare in classical sources, and of doubtful etymology; Delamarre suggests it as a Latinised borrowing from Gaulish. (Wikipedia, s.v. [List of gladiator types](https://en.wikipedia.org/wiki/List_of_Roman_gladiator_types#Andabata)) > > > The reference in Wikipedia is to M. Tullius Cicero, [Epistulae ad familiares](https://en.wikipedia.org/wiki/Epistulae_ad_Familiares) (Letters to Friends), [7.10.2](http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0009:book=7:letter=10&highlight=andabata): > > (Cicero writing from Rome to his protégé [C. Trebatius Testa](https://en.wikipedia.org/wiki/Trebatius_Testa) in Gaul, in November or December 54 BC) > > > Sed tu in re militari multo es cautior quam in advocationibus, qui neque in Oceano natare volueris studiosissimus homo natandi neque spectare essedarios, quem antea ne andabata quidem defraudare poteramus. Sed iam satis iocati sumus. > > > However, in military matters you are much more cautious than at the bar, seeing that you wouldn't take a swim in the ocean, fond of swimming as you are, and wouldn't take a look at the British charioteers, though in old time I could never cheat you even out of a blind-folded gladiator.² But enough of joking. > > > ²) Andabatam, a gladiator with a closed helmet covering the face, who thus fought without seeing his adversary. > > > ([Translation and note](https://en.wikisource.org/wiki/Letters_to_friends/7.10) by [Evelyn Shuckburgh](https://en.wikipedia.org/wiki/Evelyn_Shirley_Shuckburgh), 1901. Available on Wikimedia.) > > > Note that the andabatae were considered comic relief -- they fought for the entertainment of spectators. Nobody paid to see blindfolded men bumbling around; and the Romans actually knew a thing or two about gladiators. > > For the poor, and for non-citizens, enrollment in a gladiator school offered a trade, regular food, housing of sorts and a fighting chance of fame and fortune. Mark Antony chose a troupe of gladiators to be his personal bodyguard. Gladiators customarily kept their prize money and any gifts they received, and these could be substantial. Tiberius offered several retired gladiators 100,000 sesterces each to return to the arena. Nero gave the gladiator Spiculus property and residence "equal to those of men who had celebrated triumphs." > > > (Wikipedia, s.v. [Gladiator](https://en.wikipedia.org/wiki/Gladiator). The quotation is from Suetonius.) > > > Finally, here is an extract from [The Private Life of Romans](https://www.gutenberg.org/files/40549/40549-h/40549-h.htm) by Harold Whetstone Johnson, Chicago, 1909, available at [Project Gutenberg](https://www.gutenberg.org): > > Gladiators fought usually in pairs, man against man, but sometimes in masses (gregātim, catervātim). In early times they were actually soldiers, captives taken in war (§347), and fought naturally with the weapons and equipment to which they were accustomed. When the professionally trained gladiators came in, they were given the old names, and were called Samnites, Thracians, etc., according to their arms and tactics. In much later times victories over distant peoples were celebrated with combats in which the weapons and methods of war of the conquered were shown to the people of Rome; thus, after the conquest of Britain essedāriī exhibited in the arena the tactics of chariot fighting which Caesar had described generations before in his Commentaries. It was natural enough, too, for the people to want to see different arms and different tactics tried against each other, and so the Samnite was matched against the Thracian, the heavy armed against the light armed. This became under the Empire the favorite style of combat. > > > Finally when people had tired of the regular shows, novelties were introduced that seem to us grotesque; men fought blindfold (andabatae), armed with two swords (dimachaerī), with the lasso (laqueatōrēs), with a heavy net (rētiāriī), and there were battles of dwarfs and of dwarfs with women. Of these the rētiārius became immensely popular. He carried a huge net in which he tried to entangle his opponent, always a secūtor (see below), despatching him with a dagger if the throw was successful. If unsuccessful he took to flight while preparing his net for another throw, of if he had lost his net tried to keep his opponent off with a heavy three-pronged spear (fuscina), his only weapon beside the dagger. > > > [Answer] I Darius Quintus, one of the top 200 unluckiest gladiators, have devised a potential successful strategy for my poor century of doomed souls. Primus: Accept that every single one of us is already dead, because blindfold fighting with shortswords is basically russian roulette with all but one chamber loaded survival-wise. HOWEVER with my tactic we may be victorious! (and by victorious I mean some of our side may yet live.) Secundus: Draw lots for position beforehand and form into 5 ranks, tightly backed with about a foot of space between each man sideways, and only slightly more front to back. The front two ranks will be side-on to the enemy. We will anchor our line on the left fence. (The majority of us will likely be right-handed, if not all is reversed) The front rank will utilize the standard stabbing techniques of the gladius, at chest/belly level. The front rank will have their left arm gripping the man to their left, with the farthest-left man holding the fence. Should the man on your left die, stab front and sideways until you feel a reserve move up. Third (I have exeeded my latin): The front rank will deliever the two standard strokes as rapidly as they are capable of for a sustained period of 8 minutes. Given the pace of the murderous back-fences the battle will be over one way or another by then. They need not vary their strokes because the enemy is blindfolded and cannot learn from their fellow's deaths or time the predictive nature of repetitive blows. Fourth: The 1st and 2nd ranks will use their left hand to hold the man on their left. The second rank will have their right (sword) hand with fist/pommel pressed against the shoulder blade of the man in front. If at any point they cannot feel the man's back (due to his almost-certain death) they will commence the two standard strokes described above until death claims them or battle ends. Fifth: the third and fourth ranks will keep their blades in their loincloth straps, and be half as many men as the other ranks. The 3rd rank's job will be to keep one arm on the two men in front of them. Should one fall, they will pickly slap the 4th ranker on the appropriate side. The 4th ranker will be walking backwards and have both his arms on the 5th rank "reserve" and pass up his men. He will be able to reach both the two men right in front of him and the ones to either side, which means more reinforcements for a slot in the line than "just" 5 men if things get dicey. Should the 4th ranker no longer feel reserves he is to draw his sword and move as the 3rd rank requires. When the 3rd rank no longer feels a man at his black he is do draw his blade and act the same as a 2nd ranker. Sixth: the 5th rank will start touching a man in the 4th rank who isn't touching them, to ensure maximum rapidity of passed commands to bring up the reserve. Seventh: When battle commences the line will move at a quick walk 30 paces, then proceed at half pace. In a perfect world the line would slant backwards towards the center of the pitch to cover the exposed flank, but keeping any sort of complex formation while glindfolded is hard enough that this cannot be relied upon. Therefor the rightmost file will utilize a slashing motion instead of using their right hand to guide. This is the most dangerous position, for if the enemy attacks our flank in numbers there's not much to do but give a word of command (which the men are trained to repeat 3 times when they hear it to ensure it passes to the whole formation). Eight: Once the word is given the formation will attempt to shift in-place and face the mass to our right. Likewise if the formation goes 100 steps forward (roughly 1/4 into the opposing side of the pitch) and the front-liners give the second word of command to show they have not been in contact for 10 paces, we will face right and advance crosswise. That formation will be the same as described above, but with both end-files slashing to the side. Ninth: As you can see any motion in the formation brought about by step 6 or 6 will likely shatter the formation as a single block. The emergency fall-back order for gladiators who lose the formation is, if they lose contact with both sides, move directly fowards as best they are able stabbing forwards. If they bump into someone from the side they are to stab if there is any question at all tha the person they bumped into isn't going their same direction. If they are going the same direction the hand-code should be given before stabbing. Tenth: should a gladiator or group of gladiators which loses contact with the main force contact any fence, they are to put their backs to it and yell my name, stabbing outward continuously. All others on our side are to avoid the noise, so the lost gladiators know anyone coming near is an enemy. Lastly: All directional contact between gladiators (ie: contact made after initial deployment used to give orders) will be made with a fist that has the first two fingers and the thumb extended, then the actual grab-tug-into-place. Touch is the most noticeable of the sense, and with luck utilizing this method will stop blind gladiators reacting to flailing limbs of the dead and dying rather than actual commands or hesitating if the enemy grabs them. So there it is. Not a flawless plan by any means. But against an enemy who believes the fight is hopeless and doesn't plan at all it should be enough to ensure they are wiped out before we are. The biggest flaw in this plan I can see is if the enemy copies it exactly. At that point neither force will ever contact the other before we're both crushed to death by the advancing spike-fences. But the Emperor (may he be forever shamed for his poor choice of unique gladiatorial event!) might intervene in that case if both sides look out for blood and just can't find each other! ]
[Question] [ I'd like two medieval societies to be separated from one another by a huge vertical wall. The wall is so high that no-one has succeeded in shooting an arrow (or anything else) over it. It disappears up into perpetual mist. This wall bridges a pass in the middle of a mountain range that no-one has managed to scale because of the continual blizzards that rage and indeed the traditional stories about fearsome beasts that live there. This wall is solid. There is no magic involved - it was built by an ancient civilisation. The present-day civilisations can see each other through the wall but can only communicate in sign language. In fact the only people really interested are the children who spent a lot of time making faces and throwing stones at each other, all to no effect. Also of course there are medieval tourists who come to gape at this marvel. --- The problem is that I want it to be smooth, unbreakable, unclimbable but most of all transparent. What can this wall be made of? Could it be glass, diamond, some other real transparent material? How thick would it be? A huge wall of ice would not be transparent, and would constantly need to be replaced at the top because of melting at the base. So I exclude that unless someone can prove me wrong. To sum up: The wall must have survived for thousands of years, still be transparent (at least if given a wipe) and strong enough not to have been substantially damaged. Question Without the use of magic and using science that could really be done by an advanced civilisation with enough resources, can the wall be self-supporting and what should it be made of? EDIT - I should have provided some idea of the shape and scale of the mountain pass. I won't change anything here because I don't want to invalidate any answers. However if you look at my own answer (vertical conveyor belt) to my question below, I've added some links to pictures giving an idea of what I was imagining. [Answer] Quick answer: Some sort of indistinguishable-from-magic force field. There's no material of which modern materials science is aware that would have the structural and optical properties you're seeking. Diamond, even if it could be made large enough, has terrible shear strength, so being able to resist wind for thousands of years would be insufficient - plus, of course, a suitably determined effort with other diamonds would get through it. (For that matter, even leaving aside the optical properties, the wall as described is likely to be almost impossible to build - even hypothetical building materials need structural supports and buttressing lest they simply be blown over.) So the ancients built a force field projector powered by geothermal energy that creates a solid, inch-thick "wall" which leverages physics properties of which we're not aware to create a solid barrier through which only electromagnetic radiation can pass. [Answer] There is no material that meets the requirements of being transparent and completely unweatherable, unscratchable etc... over thousands of years. Even diamond isn't that impervious, if you take grandma's ring to a jewellers they will often find a slight chip from daily wear. Therefore, we need some sci-fi handwaving here. This wall is either made of unobtantium or can self-repair. Each of these stretches physics in uncomfortable ways Unobtainium * Go nuts, perhaps define it as an ultra-hard ceramic or a metal of unusual properties. Self-Repairing * Automated nanites? How about a diamond wall with Nanites that can recover carbon from the air and insert those atoms into the diamond to maintain a perfect lattice of great optical clarity. Although this suggests an active tech facility that maintains the nanites and, perhaps, atmospheric processing to obtain the carbon. PS. Not hearing anything through the wall is hard (conduction of sound through a solid is excellent -- cup-on-the-wall type methods would work pretty well). You might need the wall to hum or something to drown out these sounds. Or have an air-gap in the wall that somehow doesn't get filled with snow. [Answer] The closest idea I can come up with is sapphire (or other [transparent ceramics](https://en.wikipedia.org/wiki/Transparent_ceramics). It can be clear if made that way, it is a 9 on the hardness scale so unless you scratch a diamond across it it would be very hard to leave marks on, and when properly mixed with other substances during creation things like it can be used in bullet proof windows for armored vehicles (see [Aluminum oxynitride which is like sapphire with extra bits](https://en.wikipedia.org/wiki/Aluminium_oxynitride)). This coupled with an absurdly high melting point should make it more or less indestructible to medeval civilizations. If you make it thick enough to support being tall enough that nothing goes over it (say ballpark 10m thick at the base with a gentle taper up to 100m) at ground level you may be able to mar it but it is naturally resistant enough that it is doubtful people would be able to seriously damage it without a lot of time, effort, and explosives though I'll be honest I am not sure the compression strength of sapphire is high enough to support such a tall and dense structure. Maybe have hollow portions higher up to get rid of some of the weight or have opaque materials at regular intervals for supports To ease the completely unbreakable portion of your description since you are talking about a relic of an advanced civilization it could be that the wall has a method of self repair like a gene tailored bacteria or nanobots that refill any cracks, scratches, etc that might occur. [Answer] Time/Space Sheer field This section of reality is sheered in such a way that the time/space location on the other side is completely different. Even if the two medieval civilisations circumnavigated those mountains, they would only perceive the field from the opposite direction. The sheering permits photons (massless objects) through but seriously twists, deforms, and even repels mass that reaches a certain point. It would also explain why sound cannot penetrate. The internals of this wall are effectively a vacuum. As for the power requirements, a civilisation that has time/space sheering knowledge to the ability of this wall, could easily transmit power through a much smaller time/space shear from some astronomical power source such as a neutron star/black hole/etc... [Answer] You need a secondary structure, a primary one, and transparent cladding Modern day skyscrapers are often clad in glass, to form full height glass 'walls'. This is achieved with what is called a 'curtain walling system'. It is essentially a primary structure, with a secondary structure attached that supports smaller glazed panels. This enables the following advantages: * The wall is not supported by glass, but instead a protected robust structure behind it. * The wall is partially flexible, wind loads could slightly bend the wall as the glass is segmented. The secondary structure under could cater for deflection, while the primary structure caters for the main static load. * The glass could be as thick, strong or rigid as needed, just being accommodated with a thick structure as needed behind it. * The structure behind can be a truss-like structure, using lightweight steel elements (much like high voltage towers), in particular if you do not require the wall to be habitable. The interior structure has the added advantage that it is protected from weather. * The primary structure being protected could be large concrete columns, or thick steel columns, as large as is necessary * The glass could be replaced individually from behind if any damage occurs, some systems have internal fixing frames intended for interior access in case exterior access is not possible. An example architectural detail of a framed curtain wall: [![enter image description here](https://i.stack.imgur.com/boPU5.gif)](https://i.stack.imgur.com/boPU5.gif) An example of an alternate frameless, spider joint supported detail, with a secondary structure (primary not shown): [![enter image description here](https://i.stack.imgur.com/uJYWj.jpg)](https://i.stack.imgur.com/uJYWj.jpg) [![enter image description here](https://i.stack.imgur.com/2n3Pk.jpg)](https://i.stack.imgur.com/2n3Pk.jpg) There is theoretically no limit to the height of these structures (as is exemplified in our tall buildings today), with greater size only requiring greater structure behind depending on wind load. Thickness can be increased for longevity if needed, and if there are no economic considerations, increased at whim to last centuries (a lot of existing curtain walling systems have been in existence for a long time with little to no maintenance). [![enter image description here](https://i.stack.imgur.com/qIEMR.jpg)](https://i.stack.imgur.com/qIEMR.jpg) [Answer] Wind, so the material is air. Natural wind is funneled by a gargantouesque ravine reaching far away and creating the effect you describe. If ever the wind decreases to much (after some extraodinary event) the walls heat and natural fournaces below come into action in contact with water projecting streams of vapor. Water below might also be a carved system of water streams and tanks. [Answer] Rock crystal [![enter image description here](https://i.stack.imgur.com/jXyJI.png)](https://i.stack.imgur.com/jXyJI.png) (Quartz) has the lowest potential for weathering and consequently it is very common as a residual mineral found in veins within sandstone which could have weathered each side , at the head of a mountain pass the rain would wash the sandstone down each side of this cleft between phenomenally steep valley sides thus there are no holes through or around it.. Could be top heavy crystalline the higher it gets since the ancients were mining in from each side, but for whatever reason the hardest transparent core had not been finished and past attempts to climb or dig at it have resulted in shards falling from above, keeping later attempts at bay due to the gods displeasure ? [Answer] There's a different problem here. You have the wall being impossibly high, ridiculously long, impervious to damage, impervious to sound, and perfectly clear. Okay. Let's just take that as given for now. You say that it's a place where people come for tourism, to communicate via sign language, and (for smallish children) to throw rocks at it. Fine. Then you say that it's across a pass in a mountain range, where the storms are bad enough that no one has ever managed to get over the thing (and also there are terrible beasts). That's a problem. In particular, no one would go there. A pass that's that treacherous is the sort of thing that people only climb to with strong reason, and "gawk at the folks who can be seen but not heard and not touched" isn't a strong reason - especially not since they'll have the same sort of pass on their side, so most days they won't be showing up either. If you want people to actually interact with this thing more than about once a generation, and if you want them to have any contact with one another through the wall at all, you need to make it reasonably accessible. If you do that, one of the things you will see, I suspect, is architecture. Having an impossibly tall, smooth wall that won't fall over no matter how much weight you put against it is potentially really useful from an architectural standpoint. The opportunity to leave the glass wall side of your building open, and thus to do socially shocking things where you know that people can see, but they can't possibly inform anyone you care about is just bonus. (Walking about without a hat? Scandalous!) [Answer] I see a few comments related to "aluminum" and I recall from Star Trek, the concept of Transparent Aluminum and turns out, has been created. Further reading per the link suggests Iron can also be made transparent - see below: <https://en.wikipedia.org/wiki/List_of_Star_Trek_materials#Transparent_aluminum> Pure transparent aluminum was created as a new state of matter by a team of scientists in 2009. A laser pulse removed an electron from every atom without disrupting the crystalline structure. However, the transparent state lasted for only 40 femtoseconds, until electrons returned to the material. A group of scientists led by Ralf Röhlsberger at Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany, succeeded in turning iron transparent during research in 2012 to create quantum computers. [Answer] Vertical conveyor belt I've been thinking about some of the objections and have come up with answer to my own question that might work. Maybe it could even be made of thick glass. The wall could be blocking a tall narrow rectangular cut through the mountains - an artificial pass. The wall could be quite narrow (say enough for ten-abreast to pass through) and thus supported all the way up by a frame. EDIT - Apologies - I should have made something clear when posing the question. In my imagination the pass is cut through the mountains by the aliens. It looks something like the following only much more smooth-sided and rectangular. The pictures are from the ancient site of Petra. <https://en.wikipedia.org/wiki/Siq> > > <https://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/PS-Petra_6148.JPG/1200px-PS-Petra_6148.JPG> > > > <https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/V%C3%A4gen_in.jpg/800px-V%C3%A4gen_in.jpg> > > > The wall consists of sheet of material that slowly emerges from a slot at one side of the pass and eventually disappears into a slot on the other side. Behind the scenes, the material is melted and reformed after which it goes through another slot and back to the starting point where the same thing happens. Thus the wall is a kind of continuous vertical conveyor belt whose surface is always being renewed. Problems There would have to be a substantial cache (of sand in the case of glass) or other renewable source of wall-material to make up any losses from natural wear-and-tear. An enormous power source would be required but I suppose it could be nuclear. [Answer] This may not be exactly what you described, but one idea could be to use screens/projections on each side. The "wall" could be built out of regular material, at least on the inside, with some form of ultra-hard glass (or [transparent-steel](http://science.sciencemag.org/content/62/1603/xiv.1)) coating the outside. Each screen then projects a live feed of the other side. To a medieval civilization this would more or less look like a transparent wall, with each side seeing a projection of the other. The display itself could even use some advanced form of e-paper tech in order to avoid backlight issues. While this can maybe solve some of the issues of material and structure of a solid wall, it does of course pose questions about power supply and wear/tear on the hardware itself. This could be ignored by claiming it uses futuristic self-repairing tech, but it really depends on the setting. [Answer] Magnetic Barrier A very, very, very strong magnetic field would be both entirely transparent and impervious to all materials\. Because it's not a static surface it will always remain perfectly clear as it won't collect dirt or debris. How does it work? Unlike [ferromagnetism](https://en.wikipedia.org/wiki/Ferromagnetism), which is a property only exhibited by a few materials, [diamagnetism](https://en.wikipedia.org/wiki/Diamagnetism) is a property of all materials. Given a strong enough magnetic field everything* would be repelled\. To anyone experimenting with this "wall" it might appear to be soft. As they begin to press against it they would feel increasing push back as the repulsion force builds until they can't press further (which may become painful). Objects thrown again this "wall" would have a slight bounce back. [Sound can also be controlled by magnetism](https://www.nature.com/articles/nmat4247). The "wall" could be deliberately engineered to reflect sound back to its source. However the very nature of such a strong field may perturb the phonons of sound enough to make the "wall" naturally acoustically impermeable. \ Strictly speaking a field strong enough to repel solid objects would only have a weak interaction with sparse substances such as the oxygen and nitrogen in the atmosphere. Perhaps producing a slight wind and/or higher levels of oxygen at the wall. Additionally, photon lensing would be imperceivable at this level. [Answer] ## Relax the definition of "Transparent" As several other answers have discussed, building a massive, impenetrable wall out of transparent material is impossible. But if the ancients had advanced technology, the same effect can be achieved without the wall actually being transparent in the sense that light passes through unobstructed. Simply cover the wall on all sides with a [cloaking device.](https://en.wikipedia.org/wiki/Rochester_Cloak) In essence, make the whole thing a screen that shows the viewer the light hitting the wall on the opposite side, captured by nanotech cameras or similar. Rudimentary versions of this technology already exist (with varying degrees of success). For fictional ancients with advanced technology, a perfected version that shows the correct image from any viewing angle should be trivial. Cover the screen with a layer of diamond to protect its "transparency" from attack, and then build the wall out of whatever you want. The bigger and more sturdy the better, so there's room on the inside for the massive computers required to make the thing run. Since you've already got sophisticated computers powering the thing, adding a noise cancellation module seems straightforward. [Answer] The Wall is an surreal absurdity. <https://www.nytimes.com/1978/05/07/archives/surreal-and-absurd-surreal.html> > > The paradox of this kind of literature is that if the symbols are too > easily comprehensible they tend to appear monotonous and‐ trite, while > if they are totally opaque, they offer no purchase for the mind and > merely replace the Absurdist face of the world by an impenetrable > surface of apparently random verbal signs. The ideal solution, not > easy to achieve, is a convincingly pregnant mystery. > > > With a wall like this, your fiction should be absurdist and surreal. A clear wall separating 2 societies is going to be a metaphor. If you establish that it is clear aluminum oxide that falls under trite. Leaving it up in the air will be frustrating. Best: you can have various characters explain it in detail and have it be different each time. In the absurdist tradition, each citizen can have his or her own persuasion about how the wall works and what it is made of - glass, or wind, or force, or living creatures, or an erotic dream. I can envision the same character who put forth one explanation then putting forth a different one later in the story. If challenged, the character may or may not recall his original explanation, and will good-naturedly try to change the subject. [Answer] A dense packing of optical fibres, endlessly rising from the ground. This would give observers the impression of people being inches away that in reality are meters distant. An underground source let's it rise up, taking any damage with it (making it impermeable) and slowly disintegrating in lofty heights (keeping its secret). The height is what makes it unsurpassable. If the world otherwise has never seen a TV-stone no one would figure it <https://en.m.wikipedia.org/wiki/Ulexite>. The see- through would be quite limited, but the weird 'right below the surface' vibe of anything that IS seen might make up for it. [Answer] You want transparent, AND immune to surface degradation by thousands of years of wind and weather? In a mountain range, thus 100% guaranteed to be an earthquake zone at least in the very long term? That is a very tall order! Even a diamond surface would fail the test, you would have to resort to some mumble-fumble-handwaving forcefield or outright magic. [Answer] It can't be done in a science-based way. Diamond might come close, but it's a brittle material. Hit it hard with a sharp point (hardened steel, or rock) and it will crack. Toughened glass is more resistant to cracking, but shatters very spectacularly if you apply enough force (or grind your way through the outer toughened shell). You might try "toughened diamond", with no further explanation. Metals are resistant to cracking, but the physics which makes this so is the same physics that makes them opaque and reflective. I'm tempted to add that it's obviously a General Products hull derivative, and so Puppeteers must be involved. "One giant molecule with its atomic bonds artificially strengthened using the output of a small nuclear reactor ..." Good handwavium, but impossible given science as we know it. [Answer] The materials of the neutron star or white dwarf can be extremely thin, transparent and cannot be influenced by any chemical way and their mechanical hardness is absolute for a medieval civilization. Our contemporary science cannot create or keep such walls (same as superstrong walls of usual materials), but we are talking about some hypothetical super-civilization. ]
[Question] [ I'm trying to create a people that live on this rolling tide (see [previous question](https://worldbuilding.stackexchange.com/questions/126102/massive-tides-and-resources) or on '[millers planet](https://worldbuilding.stackexchange.com/questions/19503/what-would-infrastructure-look-like-on-interstellars-millers-planet)') but I haven't figured out where they would get wood to build their boats/homes. If the tide was slow enough there are some types of trees that can grow 8ft a year, so maybe have trees growing between tides. Is having trees grow between tides the only way people could get materials? [Answer] Maybe you can get some inspiration from the Uru People that live over Lake Titicaca. They create artificial floating islands, with small houses on it, with a plant called Totora. This plant commonly grows at a water depth of 2.5–3 m (8.2–9.8 ft) but occurs less frequently as deep as 5.5 m (18 ft). [![enter image description here](https://i.stack.imgur.com/eygX0.jpg)](https://i.stack.imgur.com/eygX0.jpg) <https://en.wikipedia.org/wiki/Uru_people> <https://en.wikipedia.org/wiki/Totora_(plant)> <https://en.wikipedia.org/wiki/Lake_Titicaca> [Answer] Perhaps on your world, seaweed grows up to the surface like in the Sargasso Sea. If so, that seaweed could be harvested and dried into a building material. Perhaps its natural saps form a resin which make it almost wood-like once dried. So the harvesters pull it up, and lay it out in overlapping crisscrossed layers on open topped rafts. * Need a one inch thick board, that takes ten layers. * Need a support beam might need a hundred layers. Weave it into whatever you want. Just make sure to get the shape right before it dries because the metal saws needed to cut it afterwards would be very rare on a water world. [Answer] The best real-world example to use here are the Inuit. They live in the coastal arctic, an area with no trees. However, they get around this by using driftwood that washes up on their shores. If trees are able to exist at least SOMEWHERE on this planet, then you can just have everyone do this. If there are no trees on their planet, have them use stone, coral, or dried kelp fronds. [Answer] Why use wood? Umiaks and Kayaks have been made from whale and seal bones and skin. I see no reason why a sufficiently motivated population can't scale that up, perhaps using pontoon like structures, to larger structures. <https://en.wikipedia.org/wiki/Umiak> [Answer] Ice. [![ice and newspaper boat](https://i.stack.imgur.com/TLb2y.jpg)](https://i.stack.imgur.com/TLb2y.jpg) <https://www.youtube.com/watch?v=iHufDv6obrU> Pykrete is ice reinforced with wood chips. You could use other materials besides wood chips - here the Mythbusters built a boat out of ice and newspaper and it worked great. Your people could use ice and seaweed, or hair, or whatever else they had handy to act as a scaffold. In WW2 the British made a serious attempt to build an aircraft carrier out of pykrete. <https://en.wikipedia.org/wiki/Project_Habakkuk> > > The project would have been abandoned if it had not been for the > invention of pykrete, a mixture of water and woodpulp that when frozen > was stronger than plain ice, was slower-melting and would not sink. > Developed by his government group and named after Pyke, It has been > suggested that Pyke was inspired by Inuit sleds reinforced with > moss... Pykrete could be machined like wood and cast into shapes like > metal, and when immersed in water formed an insulating shell of wet > wood pulp on its surface that protected its interior from further > melting. > > > You can make a boat out of anything which will hold a shape such that it displaces more than its weight of water. Reinforced ice works fine. I think the problem with Project Habbakuk is that an aircraft carrier has to be so large. A smaller boat would be doable. [Answer] Miller's Planet as shown in the movie had thousand-foot-tall waves every few minutes, atop a hard surface, with breathable air. Microbes in water could survive, happily photosynthesizing whenever they were near a surface. I think that the surface would not be hard, due to constant erosion. Suppose a deep surface of grit, suffused with water, underneath a dirty sea. Earthlike rooted plants would be destroyed by every passing wave, unless they were adapted to the enormous pressure of the passing wave, and the quick changes in pressure. Suppose : a plant starts deep in the grit, reaching all the way down to the bedrock. It has a tough tube it sends up into the water. After a wave passes, from inside the tube, a leaf unfolds, sitting for a few minutes in sunlight. When the water is disturbed again by the next coming wave, it retracts into the tube and hides deep in the muck. Consider that wood may be too brittle for most of this planet. Consider that the poles have zero or small waves compared to the equator, as long as the axial tilt is zero and the planet orbits on the ecliptic. If so, there is a small area on each pole that is not destroyed by waves all of the time. If so, macro biology can set up there. You can have Everglades-style trees with permanently-wet roots. Let's suppose that the average temperature of the planet is High Goldilocks, so that the poles are temperate. If so, humans can arrive on the poles and start mounding up grit and plants. When you have dry land, you can fire clay. When you have clay, you can refine metal. Etc, Etc. A polar community on a zero-tilt planet has no real night or day. But on a tidal wave planet, the host body fills up a significant portion of its sky. ]
[Question] [ I would like my human colonists to settle on the high plateaus (2500-3000m above sea level) of my planet thus never meeting the civilization living in the lowlands (in a huge forest so they aren't visible from above), until settlers find evidence of them and decide to see what's going on down there. The thing is that I need a reason why they wouldn't go to those lowlands earlier, so something that makes the descent difficult but not impossible, and also why my civilization wouldn't develop on the plateau. Here are the main ideas I had: * Hostile environnement at the edge of the plateau. I don't think it could stop my civilization, humans lives in deserts and very dense rainforests with plenty of deadly animals, nor why wouldn't my colonists just go through it with their technology but if you have any idea how it could work it's ok * Oxygen levels (or any other gas). This my favourite idea but I'm not sure it would work. It's easy to make my civilized species highly oxygen-needing so they can't live on the platea. For my colonists I know that high pressure of most gases are dangerous but is there any effect that is just very uncomfortable, like the light hypoxia you feel when above 3000m or so? If you have something that could make the second idea work it's perfect, otherwise just find something that could fix the first or a brand new one. Background: My story takes place in the 22nd century. The colonists are mainly scientists who came here to explore and study the planet. There are 50 and they have buggies, guns and an helicopter. A few months before the evidence of alien civilization, all the AI in these are destroyed by a computer virus which came in a message from earth (but it might be an e-mail they didn't open before). The purpose of the virus was to destroy all the AI used on earth and it was send in basic telecommunications from NASA. Now they just have some basic technology like solar panels and everything that didn't have any AI in it. I'm not sure why wouldn't they have pressurized air tanks. Basically they had advanced technology but no incentive to go to the lowlands, then later they have only basic technology but must be able to go in those lowlands, and I'm wondering why they didn't have incentives to do it before. [Answer] You have already solved the problem via your backstory. 50 people, alone on a planet, with less than the equipment they planned to have, would have to take on a defensive posture. With so few people, they must have been planning to depend on robotic workers which would have been controlled by the AI. Now that that is not an option, they have to learn how to do all of the manual tasks which the now-useless robots won't be doing. * They need to get the fields planted before their food stocks run out. * They need to build winter-proof shelters while the weather is warm. * They need to repurpose all of the formerly AI controlled equipment to work under human control. Nobody has time to do any exploring of the lowlands or anywhere else. [Answer] Nitrogen narcosis. Poul Anderson had a setup like this in New America. <https://openroadmedia.com/ebook/New-America/9781497694316> > > Civilization on Rustum has come a long way since its early days, when > a few brave colonists traveled twenty light-years from Earth to found > a society, New America, on the principle of personal liberty. Some > call themselves Constitutionalists, others Jeffersonians, but whatever > the title everyone can agree: Rustum has a problem. With > one-and-a-quarter times the gravitational force of Earth and a host of > inedible flora, Rustum is most habitable on its highlands, leaving the > lowlands sparsely populated and creating a great imbalance on the > planet. > > > Dan Coffin, an original settler of Rustum, agrees to join an > expedition back to the lowlands, where he is one of the rare > individuals who can survive in the dense air without a helmet. New > America follows Coffin’s endeavors to build a new life with a wife, > children, and an effective governing body that can help give the > lowlanders not only survive, but thrive. > > > But why, specifically, is the dense air problematic? The easiest way is to have unadapted persons suffer from [nitrogen narcosis](https://en.wikipedia.org/wiki/Nitrogen_narcosis). Nitrogen gas under pressure can make you feel really drunk or really high. > > The most dangerous aspects of narcosis are the impairment of > judgement, multi-tasking and coordination, and the loss of > decision-making ability and focus. Other effects include vertigo and > visual or auditory disturbances. The syndrome may cause exhilaration, > giddiness, extreme anxiety, depression, or paranoia, depending on the > individual diver and the diver's medical or personal history. > > > This is why people doing deep dives replace some nitrogen with helium in the mix they breathe. Nitrogen narcosis is good for a narrative because if you have characters which have this happen, they can act weird in different ways that help the story. More fun than having them puke or itch. Nitrogen narcosis starts to happen at 2-3 atmospheres pressure which you can achieve in your lowlands by having more gas in the atmosphere total, or having higher gravity. [Answer] You say the explorers or colonists > > settle on the high plateaus (2500-3000m) > > > of your planet. 2500 meters is 8,202.1 feet, while 3000 meters is 9,842.52 feet. You didn't say if 2,500 to 3,000 meters is the height of the plateaus above sea level or above surrounding terrain, which could have a considerable elevation itself. It is possible that the plateaus are surrounded by high mountains that it is difficult to cross. > > the barometric formula, sometimes called the exponential atmosphere or isothermal atmosphere, is a formula used to model how the pressure (or density) of the air changes with altitude. The pressure drops approximately by 11.3 Pa per meter in first 1000 meters above sea level. > > > <https://en.wikipedia.org/wiki/Barometric_formula>[1](https://en.wikipedia.org/wiki/Barometric_formula) Wikipedia lists 67 settlements between 3,700 meters (12,100 feet) and 4,700 meters (15,400 feet) and 7 settlements between 4,710 meters (15,450 feet) and 5,130 meters (6,830 feet). <https://en.wikipedia.org/wiki/List_of_highest_cities_in_the_world>[2](https://en.wikipedia.org/wiki/List_of_highest_cities_in_the_world) > > Altitude sickness typically only occurs above 2,500 metres (8,000 ft), though some are affected at lower altitudes.[2](https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans) Risk factors include a prior episode of altitude sickness, a high degree of activity, and a rapid increase in elevation.[3](https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans) Diagnosis is based on symptoms and is supported in those who have more than a minor reduction in activities.[2](https://en.wikipedia.org/wiki/List_of_highest_cities_in_the_world)[4] > > > People have different susceptibilities to altitude sickness; for some otherwise healthy people, acute altitude sickness can begin to appear at around 2,000 metres (6,600 ft) above sea level, such as at many mountain ski resorts, equivalent to a pressure of 80 kilopascals (0.79 atm). > > > High-altitude adaptation in humans is an instance of evolutionary modification in certain human populations, including those of Tibet in Asia, the Andes of the Americas, and Ethiopia in Africa, who have acquired the ability to survive at extremely high altitudes. This adaptation means irreversible, long-term physiological responses to high-altitude environments, associated with heritable behavioural and genetic changes. > > > Nevertheless, around 140 million people, just under 2% of the world's human population, live permanently at high altitudes, that is, at heights above 2,500 metres (8,200 ft) in South America, East Africa, and South Asia. These populations have done so for millennia without apparent complications.[9] The overwhelming majority, over 98% of humans from other parts of the world, normally suffer symptoms of altitude sickness in these regions, often resulting in life-threatening trauma and even death. > > > Studies on the detail biological mechanism have revealed that adaptation of the Tibetans, Andeans and Ethiopians is indeed an observable instance of the process of natural selection in acting on favourable characters such as enhanced respiratory mechanisms in humans.[10][11] > > > <https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans> [3](https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans) Humans can get reverse altitude sickness when travelling from high altitudes to low altitudes. If about 2,500 to 3,000 meters altitude on your planet has air pressure close to sea level that is comfortable for humans, then altitudes close to sea level on your planet should have uncomfortably high pressure. If your alien planet has a slightly higher gravity than Earth, perhaps about 1.05 or 1.10 that of Earth, it might not be high enough to affect the health of the explorers too much, but it will certainly make them a little uncomfortable. And the higher gravity will cause the planet's atmosphere to squashed down a bit more than Earth's, so the air at sea level will be denser relative to 2,500-3,000 meters than it would be on Earth. And it is possible that the natives live in a dense forest surrounding a large lake in some depression which is hundreds of meters below sea level on this planet and so has an even higher atmospheric pressure. Thinner air at higher altitudes tends to be cooler, so it is possible that the high plateaus seen rather hot for humans and the lowlands where the natives live seem even hotter and more uncomfortable. All gases in Earth's atmosphere or any atmosphere similar to Earth's will become toxic at high enough concentrations. 78 % nitrogen? It can be toxic at higher concentration. 0.93% argon? It can be toxic at high enough concentration. 0.04 % carbon dioxide? It can be toxic at high enough concentrations. 1 % water vapor? It can be toxic at high enough concentrations. Even the 20.95 % of oxygen in the atmosphere, vital for human survival, can become toxic at high enough concentrations. So possibly the atmosphere has higher concentrations of certain gases than Earth's atmosphere does, and the concentrations of those gases are survivable in the thin air on the plateaus but eventually lethal in the denser air at the low levels the natives live in. If intelligent aliens were discovered who lived deep underwater, going deep underwater to meet them could be a problem. If the colonists don't have submersible vehicles they may have to scuba dive to the depths that the aliens live in. Because water pressure increases very rapidly with depth, scuba divers have to increase the pressure of their breathing gas to compensate, or they won't be able to expand their lungs against the pressure. Air is used down to 40 meters or 130 feet. Various gas mixes are used to dive to greater depths. Below the depth where any air mix is safe hard suits or submersibles have to be used, which explorers and colonists might not have. If the natives live on land, the problem is how to make the altitude difference great enough that their air is so thick that breathing it would be lethal for humans, or at least very uncomfortable. It is possible, depending on the exact atmospheric composition of your planet, that a difference of 2,500 to 3,000 meters will be enough. 09-17-2018 When I was a child I once read a story by Ernst Thompson Seton where a depressed grizzly bear committed suicide by going to the "valley of death". It might have been based on the "Valley of Ten Thousand Smokes" in Alaska. But the volcanic fumes in the fictional valley were deadly. Obviously there could be volcanoes in or near the high plateaus in your story that could release poisonous gases. Poisonous volcanic gases that are heavier than other atmospheric gases might collect in lower areas and be denser there than in higher areas. Possibly the natives live in a forest almost surrounded by lower forests with lethal concentrations of volcanic carbon dioxide which helps the plants grow very lush. Radon is a dense gas produced by radioactive decay of uranium and thorium. It is produced by natural radioactive decay of those elements in rocks and soil and often concentrates in low spaces. Radon is more common in some areas than others due to differing geology. And breathing radon gas is the second most common cause of lung cancer. So possibly Radon gas is more common on your planet and more common at lower altitudes, and the colonists would want to avoid going into lower altitudes without breathing equipment as much as possible. Possibly your world could have a denser atmosphere than Earth's, even at a height of 2,500 meters, and even denser at lower altitudes. And it also has higher average proportions of various gases like argon, carbon dioxide, and radon, so that the denser atmosphere at lower levels is too toxic for humans to breath for long. [Answer] I'd suggest that the lowlands be an entirely hostile environment, if the forest is made up of something similar to, but not as nasty as, the [Manchineel Tree](https://en.wikipedia.org/wiki/Manchineel) then the colonists will stay on the high plateaus of the world and avoid the lowland forests. Until that is something worth the investment, in both time and resources, to break out, or worse yet devise, protective equipment crops up. Like the opportunity to make first contact with sentient natives. The native lifeforms would have a different body chemistry such that they rely on the human-toxic environment for their very survival so they rarely venture far enough up onto the plateaus to leave any evidence of their presence. [Answer] Raised elevations are cooler. Assume your planet is warmer than Earth. Even on the elevated plateaus the temperatures are barely tolerable. The lowlands are too damm hot and humid. Basic comfort would induce the colonists to cooler locations. [Answer] They just haven't gotten around to it yet. They've been carrying out satellite and/or air surveillance, and probably brief physical visits to collect samples from as many places as possible, but there's an entire world to be mapped and sampled, as well as a base to establish, and there's only so much fifty people can do. Even if they had visited the forested area once or twice, they wouldn't necessarily have noticed anything unless they just happened to stumble across a populated area or thoroughfare. As far as more detailed surveys of particular areas go, the forested area wasn't near the top of their list. They would have gotten to it eventually, of course, but that could easily take several years. If it suits your story, perhaps some of the scientists have been agitating for a more thorough survey of either the forest in particular or of all the area surrounding the plateau, but the commander is a by-the-book sort of person, and by the book, areas that can't be reached by air either aren't a priority, must not be surveyed at all during this phase of colonization (because of the higher risk involved) or must not be surveyed without special equipment that isn't available yet, e.g., fully enclosed vehicles of some kind. (They might have ordered said equipment and be waiting for it to arrive, or perhaps it's always been booked in for the 3rd provisioning drop, or perhaps they're supposed to build that sort of stuff themselves but the auto-fabrication machinery is booked solid for the next two years. Or they haven't mined enough of the necessary raw material yet, or perhaps the ores they need are rare on this planet and they haven't found enough yet. The details depend on what sort of technology you envisage them having, but there are endless possible variations on the same basic theme.) [Answer] This is actually a difficult question to answer, since human beings are both very curious and extremely adaptable. Consider the Ancestors, with [Paleolithic](https://infogalactic.com/info/Paleolithic) technology walked around the world, and didn't let small things like oceans, glaciers, other hominid species or predatory megafauna deter them in any way. [![enter image description here](https://i.stack.imgur.com/9Ar8t.jpg)](https://i.stack.imgur.com/9Ar8t.jpg) Guys like these walked around the world, and settled every place it was possible to support life. He would be very interested to know what's down below the plateau We (all living humans) are their descendants, and have inherited all the qualities which made them successful, so whatever is stoping the team on the plateau from exploring will have to be very extreme. This of course complicates the story telling, since whatever is so extreme that it would prevent human exploration in the lowlands is likely to make survival in the plateau extremely difficult as well. So in essence, the setting will have to be ramped up to the point the team on the plateau is doing a large scale retelling of "[The Martian](https://www.amazon.ca/Martian-Novel-Andy-Weir/dp/0553418025)". This isn't a bad thing, incidentally. An alien civilization living in an extreme and unearthly environment is much more believable in a "hard" SF setting, and if our heroes are busy trying to stay alive, this can make an interesting variation of "First Contact", the aliens creep up the mountains to see what is causing these strange lights, sounds, electromagnetic signals. How they react when they discover the team, and how the team reacts to being contacted by the aliens could make for a fascinating story. Good luck! [Answer] This is a tough one: given that your colonists have come to this world specifically to scout out the possibilities for sustaining civilisation, and that they've apparently been here for several years with full space-age tech before their AI went kaput a few months ago, it's hard to see why they wouldn't explore the lowlands. Even if the atmosphere down there is toxic (I don't know enough about gases to comment on this), surely they would at least send a few scouts in biosuits, or drone missions. However I think there is a plausible answer, based on an adaptation of what Henry Taylor said which allows you to keep your current timeframe. If the AI was indeed flawed from some time before the crash, then maybe it took a while for the corruption in the computer systems to become noticeable. Shortly after arriving, the colonists noted that conditions in the lowlands were inhospitable and decided to send unmanned robots to make a preliminary exploration of this area. These robots returned data which suggested that the lowlands were totally devoid of advanced life, and thus not worth further investigation; however, unbeknownst to the settlers, the virus was already corrupting the bots' AI and causing them to return these wildly inaccurate results. No-one realised the mistake at the time, and when the virus later got out of hand and crashed the computers outright, the settlers were too busy trying to survive the loss of all their tech to think about the implications for the earlier mission. Until now, that it... To flesh this scenario out in more detail, you would need more info about the cause of the problem with the computers (you presumably already have an idea about this). It becomes more plausible if someone deliberately planted the bug (perhaps with the express intent of sabotaging the colonists' ability to detect life) than if it was just a random programming accident, but it could still just about work in the latter case. [Answer] Don't forget a simple reason: "you can't get there from here". If your 2500m elevation includes 1000m of vertical (or even overhanging) cliff face, that would be quite a big deterrent for exploration. Such a cliff isn't too implausible, in terms of geology. A gradual uplifting of the land, plus rock soft enough to form a raised beach structure, would do the job. On earth, sea levels have changed by several hundred meters over the last 500 million years. Sure, they could use their helicopter. But reading your question literally ("helicopter", singular, not plural) would they want to risk that asset on a mission if there was no way to repair the machine or recover the crew after a breakdown? Of course your colonists might eventually find a way down, but how many months or years are they willing to spend searching for it? [Answer] I think temperature would be the best option for making it very difficult to explore the lowlands. Have this world be much like this one. <http://www.worlddreambank.org/C/CAP.HTM> The expedition sets down on a plateau at fairly low latitude where the plateau is pleasant for humans but the lowlands are lethally hot. When the computer bug strikes they have lost much of their high technology including the air conditioned vehicles that would make exploring the lowlands feasible. The intelligent natives find the highlands unpleasantly cool so they seldom go there. The natives probably fly in the high pressure lowlands so the difficulty of flying in the highlands is another disincentive for the natives visiting the highlands, thus delaying first contact. I see 2 others mentioned temperature, but I thought I would put in a more expanded version of the idea. [Answer] The AI was overbearing. Networked tools (everything above a hammer) would actively resist being carried into dangerous terrain - the definition of dangerous being done by AI (and a small superuser-key-bearing elite). Humans felt swaddled, overprotected and manipulated (a feeling that fostered the virus attack), but could not refuse the AI, it being everywhere. The AI may have known of the population below, but because of incomprehensible reasons felt it too dangerous to tell the humans. So they lived blissfully unaware of the valley dwellers, who in turn, were kept from the mesas by more robust AI intervention. Missions to new planets may seem dangerous too, but a) the definition of dangerous may be rather complex and b) this form of intelligence gathering mission may be cleared by the elusive superusers. [Answer] Simplest answer is the one that has happened numerous times. People don't explore distant hostile environments until they have exhausted their own environs. Humans settled the whole Earth but it wasn't a constant move of exploration, normally they would consolidate in an area, then population or other pressure would make them move further. Unless there was an overriding reason such as warfare the moves weren't very far each time, just far over time. Your colonists would be in the early consolidation phase. [Answer] Put some extra oxygen in the atmosphere. (Perhaps put some other gases also so as to keep the oxygen percentage from getting too high as it's a fire risk.) At this point the lowlands are toxic for long term exposure. It's possible to venture down there with special breathing apparatus but no unprotected human will go poking around down there for very long--and without vehicles the trip will take longer than the safe exposure limit. Hence it's a realm for the scientists only--and your survivors won't be wasting time on such science. [Answer] The colonists are on a plateau that would be similar in environment to a Savannah for example. This provides a path of least resistance for camp setup because of stable climate , ability to scan up to horizons for incoming predators and the like , better navigability and east to erect infrastructure. However once the colonists setup camp. They were infected with a symbiotic pathogen that disrupts the dopaminergic system. Essentially this causes a kind of laziness to set in. Although they would do enough to get over the day . Their will to explore and see out what is below has essentially been zapped. They have no intention to go beyond what they are now used to. Similar kind of laziness has been hypothesised to have caused the death of Homo Erectus <https://www.iflscience.com/editors-blog/homo-erectus-died-out-because-they-were-too-lazy-to-adapt-to-changing-climate-study-suggests/> ]
[Question] [ I'm building a game set in technologically medieval, low magic fantasy world. It contains four races: * Seafaring human-likes * Dwarven inventors employing machinery to do their bidding * Elves which live in harmony with nature * Destructive, feral, cannibalistic tribespeople Each race has been unaware of the existence of the other three until the beginning of the game, when they are all forced to simultaneously abandon their no longer viable homelands and migrate to a new, previously unexplored land. They all discover the same land which appears to be a godsend, until they come across other races. What could be a cause for migrations at that scale? Any apocalyptic events that might be the cause must not affect new land. [Answer] So the problem seems to be that your people need to come from different parts of the world, be able to cross the ocean and yet not have found each other. So you need something which opens up the possibility of reaching this new land and is also pretty devastating to the rest of the world. The things that come to mind are: * Asteroid impact: could cause tsunami's and flooding of low areas and open up new passage to sail to this new island. * Climate change - Perhaps your world is freezing and so the equator is the only reasonably habitable zone (though they might want to bring crops from their own climate as I imagine this might kill off some native plants from the equator) * Birds carrying over bacteria which infects common crops - not drastic in terms of changing the world but you might be able to explain a common plight if the birds migrate to all the different countries. I'm sure there are many many others but they would need to be disasters on a global scale. [Answer] And Noah was six hundred years old when the flood of waters was upon the earth Just turn on all the rain clouds and leave them running for a long, long time. Eventually all of your races will be vying for your world's version of Mount Everest. [Answer] They could meet in the "new world" the same way that colonial powers did in the Americas. Just saying that you don't necessarily need a cataclysmic event. Your races could just be looking to expand by colonizing a newly discovered land. Once they arrive they fight it out much the same way colonial powers did in the Americas and Africa. If a cataclysm is really necessary consider that they may have exhausted their natural resources. Overpopulation is an easy reason to strike out looking for new lands and resources. Things like blight, plague, and polution are all tied to population density. [Answer] I really love this question. There are some obvious ones like a volcanic winter, but many disasters and so on have happened on earth and never have I heard of a couple of civilizations meeting each other in a new place (new to both of them) - disasters or now disasters - in the history of our planet. Maybe there were a couple in South East Asia, but they were certainly not advanced enough to build machines. We are not talking about pre-sumerian nomads here. Also, all of this is made harder by the fact that apparently, this happens simultaneously and not over a couple of decades. I also want to rule out one empire collapsing and the other "races" invading because this doesn't sound like it's your intention. So I think an answer that is reasonable has to consider your fantasy setting. So here are some ideas: 1) Gods or related entities are behind it. The races are destined to meet, maybe to complete a task together or fight out who is worthy or whatever. 2) A meteor went down on the land you want to settle and people believe that they absolutely have to get there because of some religious reason. Maybe they think a god landed there - check out ancient cultures that worshiped meteors. 3) Another power is behind it. As I mentioned, the WC 3 approach. Some other power invades their land and they are fleeing. The other power would have to know the entire world of course. Check out WC3 (warcraft 3). Additionally, the only reasonable setting would be if it was really hard to get to that land. If you have kind of advanced civilizations with ships and all of that, they would most likely know each other. Advanced civilizations have always been very much aware of their surroundings. Yes, the Chinese and Europeans did not really meet until very late, but neither had the need to migrate and also they were at least aware apparently pretty early on. In order to try such an hail marry attempt to get to a new land, they must know it's there, it's hard to get there which leaves it unexplored and several civilizations are bordering it. I don't think a really satisfying and good answer can be given without further knowing the rules of your world. [Answer] THE COMING OF THE ICE Your solar system is a bit strange and for periods of years the planet is a bit farther from the sun then normal, before returning to its original orbit. This results in a mini ice age. The lands and seas that were once home are not just too cold. Ice burgs/sheets in the sea and thick snow on the land. Those that lived in the northern and southern hemispheres all need to migrate to the equator which can still grow planet life and farms. One of the reasons these groups of people have never meet was the equator is usually too hot to easily pass so those in the south never when north and the northerners never when south. [Answer] Locusts! Locusts! Locusts! Massive devastation to crops and vegetation caused by a plague locusts (swarming) is more than capable of forcing population migration, should the damage be great enough. What's more, it's not just farming communities that are affected, hunter/gatherer societies could suffer to a damaged eco-system. [See link](https://en.wikipedia.org/wiki/Locust#Solitary_and_gregarious_phases) Also, once the swarm ends, the ensuing locusts corpses lead to an explosion to rat populations. More rats, greater risk of disease. Bubonic Plague scenario results, ending in even greater loss of life. This takes care of our Dwarven, Elven and Cannibalistic (presumably they have to eat hunter/gatherers) factions. Unfortunately, a question remains for your seafaring people. I would tentatively suggest an algae bloom causes a red tide and kills off fish reserves. This depends on how vital fishing is to their diet. Historically speaking, seafaring people such as the Vikings relied on fishing for a large part of their diet, but also had permanent land settlements where they hunted and farmed (both domesticated animals and arable crops). [Answer] Imagine a land like Netherland: flat, all around sea level, sheltered by the ocean only by low dams (either natural or artificial). A major event generates a tsunami which destroys all the dams and flood the region, forcing the survivors to find a new place to stay. The major event could be: * a big earthquake * a massive landslide * an asteroid impact [Answer] I had a couple of ideas: Dwarven machines The Dwarves created machines which could think as well as they could (like basic AI or something) and those machines could detect other life. They can't go over oceans though so everyone the machines tracked down had to flee to the ocean and eventually they find the one land that the machines can't reach. I'm thinking maybe the machines need refueling every now and again so ocean voyages are too long. This didn't fit what the OP wanted but I've left it in anyway since it got upvotes Rising land The new land they all find could be rising out of the ocean, this would make the sea level rise too and flood a lot of the lower lying areas. This new island would probably not have much growing on it yet but you could have sea features like coral or drying seaweed over the island and then the people have more to contend with. [Answer] Nuclear winter You need an event that is: * Global * Forces massive migration movements * Doesn't wipe out the existent inhabitants of the world or makes the world inhabitable * Gather them all in a previously inhabited land With all those constraints I'm going to bet on a supervolcano erupting tons of ashes into the stratosphere. All the northern hemisphere of the planet gets a permanent grey sky, plants start to die, crops doesn't grow, hervibores die because lack of grass. It's not sudden, so neither elves, humans or dwarves die (the cannibals, who do they feed from? Themselves? You have a plot hole here) but they start migrating south instinctively, looking for warmer places. A glaciation starts as the global temperature lowers. Glaziers grow and sea level shrinks. A desert island near the equator was known to sailors, but it was inhabited due to inhospitability. However, with rain patterns changing, in the few years (less than a human generation) where civilizations have started marching southwards the continent has become a fertile, warm climate. So everybody ends going there. [Answer] ### The "Deep Ocean", Sea Monsters, and an Ice Age Here's the setup: 1. Your races start out living on different continents (or groups of islands in a shallow region of the ocean for your sea-fairing race), away from tropical regions and separated from each other by "the deep ocean". 2. There is a centrally-situated uninhabited tropical continent, surrounded by the "Deep Ocean". 3. The "Deep Ocean" between the continents is full of dangerous giant hungry sea monsters. No ships (not even those of the sea-faring people) have any chance of making it to another continent. To any given race on a continent, the existence of other continents are only rumors. Here's the cataclysm: Massive Underwater Volcanic Activity. This results in the following: 1. The oceans heat up dramatically, resulting in a lot of evaporation. 2. Because of all the evaporation, there is a lot of precipitation on the continents. 3. Sunlight is diminished from all the ash. (This actually happens on earth when there are major eruptions.) This results in colder temperatures globally, so most of the precipitation falls as snow and continually builds up, causing an Ice Age. 4. Because of all the evaporation, sea levels drop as the ice caps build up. This exposes new islands and land bridges. 5. Because of all the turmoil in the "Deep Ocean", most of the great sea monsters die out. 6. Due to extinction of sea monsters combined with islands and land bridges, travel to the central uninhabited continent is now possible. 7. In the case of the sea-faring race, most of their shallower ocean has now become land (and most of their land is covered in ice), driving them to the deep ocean in search of new land. 8. For the other races, you may have to help them out with a bigger share of islands and land bridges (and possibly less distance) leading to the central continent than your sea-faring race gets, to make it all roughly even. To Sum Up: Races can't find each other or new land because of sea monsters in the deep ocean. Underwater volcanic activity causes an ice age, killing the monsters, lowering the sea-level, exposing new islands and land bridges, and making the current lands uninhabitable with ice caps. [Answer] The easiest way would be some sort of planetary devastation. If the new land were literally a new land (planet, dimension, et cetera) then perhaps a race that new of ALL of their existences could provide portals to this new land, with the drawback that the destinations would all be very close to each other. Another, more sinister version could be that the races were forcibly kidnapped and transported to this new land by the not-so-benevolent race that knew of all of their existences. This could end with either a crash in the new land, killing the abductors and leaving the abductees to fend for themselves, or as a forced resettling either due to the abductor race wanting to experiment on them or simply wanting their homelands for their own use. [Answer] ## A villain! Have some sneaky magic dude: 1. Put some kind of problem on the land (any problem!) 2. Come as a humble traveller with stories of a distant land where problem X doesn't exist. A lot of difficulties (crops failing, flooding, wild beasts, etc) might not inspire people to move, only to despair at their misfortune. By having a character who is instigating the move, things can go along smoother. [Answer] You say "people" but don't specify how many, so for this answer I'm assuming you mean no so many. Place them on different sides of a huge mountain ridge (like the Himalayas). The seafaring humanoids come from Vietnam, the Elves from Uttarakhand, The Dwarfs inside the mountains (and maybe surface near Lhasa), The Ferals from Gê'gyai. That way they have reasonably never met (because their respective living areas are far apart). Now you start your flood. The Humans note this first, pack their remaining stuff onto their ships and sail land-inwards towards the mountains they see on good days on the horizon. The Ferals will notice it second and race for higher ground too (they don't have much to pack, so they are quick). The Elves notice it third, but are quicker due to their ability to perceive which way is good (being all nature and such). So, they too go for higher ground. The Dwarfes notice last when their tunnels start to flood. They flee upwards, most likely digging, leaving behind tunnels full of ancient machinery that is now lost forever. Each and all of them comes to the highest summits in the area which happens to be Mount Everest. Maybe some Seafarers met other tribes on other summits above 7.500 m (because that's the new sero), but we will never know (until the expansion pack). The cause of the flood is icy comets raining on earth (in case you don't want it to be actually caused by a God). Or your world had a ocean underneath the tectonic plates and it burst open (then it would be more like a tsunami, then a rain-flood, otoh the biblical flood was a tsunami as well but got reported as rain anyway). ]
[Question] [ Suppose you were an "enlightened" (male) monarch in a very backward, "traditional," unequal society. You want to lift women out of subservience in your society. You can do this one in one of two ways (but they are mutually exclusive, because you have only "one bite.") 1) You can "dictate" (and try to pass) legislation to elevate the status of women. You fear that because you (and all your legislators) are male, you might not be the best person for the job. 2) You can establish a line of succession that will allow your wife, your niece, your daughter, and your granddaughter in law to ascend the throne as female monarchs. If you were living in a world like ours, which do you choose? That is, what is likely to have more lasting impact? This question was inspired by [this one](https://history.stackexchange.com/questions/27049/did-peter-the-great-promote-rights-for-women-if-so-how/27072#27072) on the History SE site. [Answer] ## Property ownership & divorce rights. Property ownership is fundamental, and will precipitate other important benchmarks of equality, like voting rights. A striking example is women's suffrage in 1790s New Jersey. Their state constitution (via absence/use of gender pronouns) implicitly, and later explicitly, allowed women the right to vote for about 2 decades overlapping the end of the century. Why were women there allowed to vote? To cover the eventuality that a widow, left in possession of her late husband's property, could have a say in the election of local property tax assessors. Keep in mind that the US did not give women the universal right to vote until 1920, over 100 years later. Property rights would help prevent financial insolvency resulting from heirs taking property-based inheritance and leaving the widow destitute. Financial security could lead to further opportunities -- if nothing else, the possibility of an increase in time and resources, which could be dedicated to a furthering of the women's rights movement -- a snowball effect. It would be hoped that the right to hold public office would inevitably follow -- probably first as a matter of necessity in smaller communities where the number of age- or social-class-eligible males was limited (perhaps as a result of depletion from war fatalities incurred via mandated military service). Divorce rights are also crucial. Allowing women to unilaterally seek divorce can result in a whole bevy of implicit rights -- the right be safe from physical violence, the right to bodily autonomy, etc. Divorce rights would probably be an easier pill to swallow for the specified society's time period than full-fledged marriage rights (defined here as "the right to choose your own partner") -- but it's reasonable to envision them coming to pass as well, once divorce rights are on the books. The right to re-marry would be crucial in a society where limited job prospects could mean financial dependence on a male spouse. Marriage rights could mean control over a woman's dowry, which would potentially give them financial independence. Acknowledgment by the state that a woman's basic needs must be provided for could either result in an acceptance of their employment at jobs they'd been previously barred from holding -- either that, or a provision in the divorce law that stipulates, say, continued financial support until re-marriage (which would still be a win). My grasp of women's rights history is tenuous enough that I am unaware of a possible "chain of causality" that would lead from property or divorce rights to labor rights (defined here as "the right to work in a wide range of possible occupations") but my instinct tells me that a plausible one exists. It would be hoped that as technology improved, reproductive rights would likewise follow divorce & marriage rights. In a social climate unfavorable to the outright equality of women, your political capital for enacting change will be minimal, so it's important to choose carefully which rights you grant. Go for the ones that are simultaneously the most justifiable & the most likely to result in an eventual domino effect of legislative change. [Answer] England had women monarchs for a while, and women still didn't have a right to vote or own property. That's where I'd start. Make a law saying that women have rights to own property, can inherit property, hold office, and if there is something to vote on let them do it. Allowing for women monarchs wouldn't be a bad idea, just not enough in itself. This would be the minimal change to get everything started, and even in a heavily male dominated society, it should be an easy sell with minimal political capitol. You sell it like this: "Men, if you had no son, and you died, what would happen? Your lands and money would go to your closest male relative, and your family would have to rely on the kindness of others. I hope that they wouldn't throw them out into the snow. Is this right? No! By allowing women to own property, I'm not taking anything away from you! Indeed, what I want is to give you more choices. You should be able to decide who gets your estates when you die, even if you decide it's your wife or daughter!" He (or his political advisers) could personalize it for each person too. "Ivan, your son is lazy and a drunk. Your daughter has a level head and is a good, hard working girl. Wouldn't you want to make sure that she could live a comfortable life, and hope that her brother doesn't drink it all away?" "Andre, you have no sons and your brother has been lusting after your lands and money for years. If you were to die, do you really think he will take care of your wife and 3 daughters? Why take the chance? Vote for this plan, and give your family a chance at a future!" Once women get the ability to inherit, then each following step gets easier and easier, as women get more involved and have more of a say in how things are done. This is especially good if the monarch is worried he might goof it up because he's male and out of touch with female needs. Get the women helping make decisions one step at a time, and they'll make sure things are done that help women out too. [Answer] If you are a monarch, you are most likely somewhat detached from the average human existence. Just as a king does not usually know what it's like to work in the fields all day, a queen wouldn't know what it's like to cook or sew or raise children. So even if you have a queen in power, that doesn't mean they'll know how to enact laws for the benefit of womankind. Plus, if you don't change the society you're ruling, future female monarchs might have their gender blamed for anything they do wrong, eventually leading to a reversal of your decree. There is also the possibility that any male heirs who believe they have more right to the crown than the women will gain enough supporters to stage a coup, which again will foil your schemes. On the other hand, if you force society to change, by the time you die the newest generation will be used to the idea of women in the places you put them, and equality among genders should continue naturally. That is, unless the laws you dictate are really bad, and cause a lot of harm to people, in which case the people may revolt, kill you, and crown a less feminist king. Either that, or everyone will harbor increasing amounts of hatred towards women, which could have unintended consequences. So I would suggest trying the second option, but not going overboard with it. It also has the benefit of the changes taking place in your lifetime, so if things go wrong you will still be around to change them. Considering how much kingdoms have lost with inept heirs, I'd much rather handle something like this myself. [Answer] Interesting you mention Russia. 18th century there was literally dominated by female monarchs: Anna (reign 1730-1740), Elizabeth (reign 1741-1762), and Ekaterina the Great (reign 1762-1796). And women status was not lifted at all. So your second strategy just doesn't work. The first one may work, in a way similar to how post-revolution Russia implemented it. Property rights, accessible (and enforced) education, equal opportunity employment, secularization are first steps to achieve equality. Other problems may pop up later. [Answer] Divorce rights, definitively. The others (voting and property ownership) might be quite anachronistic in a time with a different technology level and social/economic organization. Voting and property ownership (not only for widows, they had the right for ownership in that era and much sooner too) are rights which today would feel very painful and degrading if removed, but don't forget, that both the economy and the society back then were differently organized, and the extended family had a much more important role. Also due to the technological level, most women couldn't have much of a chance to survive on their own. Also, especially due to higher child mortality, a society where a lot of women can pursue careers independently, would soon go extinct on demographic grounds alone (even today, with much lower child mortality, the most developed nations can feel this effect quite painfully). Why I'm writing this is that while women indeed by far had less overall rights, it was not the oppressive hellhole people now imagine it was. There were some well-respected women in that time period, it just was much harder to become one. The family as a unit was much more important not solely because of ideological grounds, but for survival. My goal is not to start a political debate, but just to help you avoid creating a society of strawmen in your story, where all men oppress women because mwhahahaha they are so evil or stupid and find it satisfying. But returning back to divorce rights. That would be the most important (and probably only reasonable) change you could to to help women. The other, more modern concepts might even backfire as they might not be embraced by women as they are embraced by today's women, they might even find it a much too uncomfortable lifestyle change. Why are divorce rights important? Because there were men who married young and naive women, and used the marriage to extort money out of the woman's family. Not sure how this particular law was in Russia, but the standard of the time in eastern Europe was, that (where divorce was allowed at all) a divorce could only happen if both parties said they wanted to divorce. This means that a man could seduce a woman and marry her, then start beating and otherwise abusing her, and telling his father-in-law that he will only agree in a divorce for a nice sum of money, otherwise he will tell before the jury that he still loves his wife. he could also legally force his wife to live with her, even if she didn't want it. Changing this would save a lot of women from horrible abuse, and could help in providing justice against those monsters who could do the above things without having to fear any legal repercussions. I'm not saying that all or most men regarded their wives to be property in that time period, but there were certainly a lot of men who did. By changing divorce law, you could significantly help reducing their numbers and making them less threatening to women's well-being. [Answer] Legislate to create a female standing army. The end goal is an overall army which is at least 50% women. Given the honour, chastity and similar issues this will require the women to be in all female battalions with female officers going up to the highest level. In general, it should be a duplication of the existing army, however, a complex maternity leave scheme may be required as being effectively forced to sign up to childlessness would make the prospect considerably less appealing to women. The recruitment/conscription into the army should aim to be identical to that for men, with noble born women filling out the officer corps. Initially, however, common women may need to be trained up the ranks to high ranking roles as it may be impossible to get hold of competent, interested noblewomen. If so, common born generals must be treated with respect and given power, both to maintain the integrity of the army and to keep the role desirable. (If you can never get hold of the noblewomen then this could be a good place to start breaking down the class system :P) Equal weight should be given to the achievements of both the male and female parts of the army and their pay should be the same. There are a number of advantages this will bring. Firstly it will educate noble born women and, to a considerably lesser extent, other women. It will also give them an independent source of income and prestige. The training will reduce the difference in physical strength between your men and women as well as giving women access to and experience with weapons. It will also give high ranking female officers considerable power which they may then expand into the political sphere. All of these things reduce the dependence of the female population on men and should pave the way to divorce and property rights (after all, you're probably going to want to keep all that hard earned cash, right?). Armies are rarely more than [1% of the population](https://en.wikipedia.org/wiki/List_of_countries_by_number_of_military_and_paramilitary_personnel) so this should have a minimal impact on the birth rate. [Answer] The OP says: > > You can do this one in one of two ways (but they are mutually exclusive, because you have only "one bite.") > > > Given ONLY the two choices the OP provided; the better option is legislated equality. The "ascension" option, after the death or retirement of the enlightened Monarch, is far more likely to lead to the immediate assassination of the female successor, or her forced marriage to a Male that then becomes King. In a world of female subjugation, the vast majority of men (the only ones with a vote) blinks twice: They don't think the Monarch was enlightened, they think his wits were addled and he should have worked harder to find a good successor that would care for the females in his charge: They don't admire him, they think him a traitor that left a power vacuum into which violence was bound to rush, and the consequence was fatal and bloody to his own family, and instability followed by a coup in the government. The addled Monarch will be vilified, not praised, and unsuccessful. Personally I am for 100% equality; but putting myself in the shoes of these fictional characters, their reactions are not pretty and a female monarch is unlikely. An alternative to violence would be overriding the Monarch and appointing a male Regent (like a child would) that would actually run the country, an "acting" Monarch, until some male was born in the Monarch's bloodline. Then the infant King would be appointed a Regent to run his affairs. In the end, such arrangements can result in a complete loss of power to the Monarch; the Regents and some committee (like Parliament) use the opportunity to parcel out the power of the Monarch which is no longer protected with force by loyalists to the Monarch. Remember the psyche of all societies that subjugate women; both boys and girls are trained from birth to believe women are not warriors, and not thinkers, and not brave, too weak and slight to be able to defend themselves, that women are addled and physically disabled by menstruation and pregnancy. The female Monarch may be physically protected by a guard of men willing to sacrifice their lives to protect her, but they are not going to protect her political power because they are warriors, and do not believe she is capable of making intelligent decisions, or commanding an army, or even dealing with foreign powers from a position of strength. Her guard may succeed in preserving her life, but they won't obey her commands any more than they'd obey a five year old: If she has a loyal guard, they will bargain for her life (and income and their own jobs) by endorsing a Regent, Husband (in waiting if she is very young), or new King of their choosing. Because of her own culturally instilled beliefs, she will likely agree to such arrangements immediately upon realizing she faces drawn swords if she doesn't, and while the people may be happy to keep her in a jeweled carriage as the Monarch's Queen or Princess, on his strong arm at Parades and Parties, they won't back her as Monarch. The Monarch's female ascension plan is stillborn. That said; earlier comments and the accepted answer cover the specific forms of legislation I would also consider priorities; I will vote for some of those. ]
[Question] [ My story requires humans very quickly creating a ~5km barricade to protect them from the monsters that live in the forest. These monsters are between animals and humans in power/intellect. Currently, I thought of cutting down every X tree along the natural tree perimeter, then attach that tree sideways to the standing trees. Basically using uncut trees as the posts. But my brother brought up a trench, which seems like more work, and more/less secure. Some animals can jump pretty far, and/or climb. To make the trench tall and wide enough would be very laborious. So I'm curious what other low-cost ways to create a barricade would be. Requirements: * The humans are resource poor, starting from scratch (wood/stone), but they do have numbers and stamina. * The barricade should keep out large and small animals. Flying ones get past. * Must be fast to set up, within a week, including overnights if necessary. // ANSWER // After reading all your suggestions, a trench sounds the most feasible for my scenario. The roman factoid gives me confidence in this idea. I forgot to mention it's on an island, so they can't run away, and the humans were there first for a decade or so, so they have some infrastructure. Burning down the forest does sound like a good idea, but I imagine the soot would kill the humans, and possibly the food sources too. In sum, I may use a combination of these suggestions as the crude methods buy more time for something better. Thanks everyone! [Answer] That's what the Romans did. They dug a pit/trench all the way around the camp, leaving 'gated' areas at the ends to get in and out. when they dug the trench they threw the dirt into a pile on the inside, making a trench down and then a hill back up which the attackers would have to travel. Giving them the high ground and making it easier to defend. On top of that the more impending the danger needing defense they would also line the trench and facing hill with sharpened stakes to slow the advance down even more. Using [caltrops](http://en.wikipedia.org/wiki/Caltrop) in the open spaces in front will slow a charge but this was for more imminent attacks. The longer they were in an area the more open space they would clear to more easily spot an enemy approaching. But I believe that the Roman legions did this at least the trench/hill every night they were on the march especially if camping in the open. [Answer] How many humans to hold down your 5km border? Low-tech? You're pretty much screwed, especially if there's a numerical superiority of attackers (3-to-1), or if you're spreading your defenders out (ie: attackers can put together a disproportionate force at one point vs. defenders at that point). The larger the border you try to hold down, the more dispersed your defenders are. If you're leaving one guy holding down 50' of border - it'll only take 3-4 human equivalent attackers (minus however effective your barrier is) to overwhelm him, and pierce your defenses, then roll up the flanks of your other defenders. If you can see them coming (low-tech means you're screwed for night attacks), and can move quickly, you can have your defenders grouped up but spread out a bit more (well, not a lot more than 100'), so they can come to each other's aid. Beware of feints to draw in surrounding defenders leaving holes in your defenses. The larger your defending group, the bigger the attacking group will need to be. Also, figure in your advantage in ranged weapons and armor. Unless your monsters are pretty tough. If you want it realistic, have your humans move somewhere with better defenses. An island, a peninsula, or land between two rivers, or as Pavel suggests, a cave. Or build a castle (and pack in the defenders). A barricade isn't going to be effective against anything that can climb, dig or leap (for reasonable barriers - if you can build them 20' high and make them smooth - maybe you've got a chance). Most predators are going to be capable of scaling 10' and 12' fences. I've seen coyotes jump over 8-10' fences. Once you start trying to build fences higher than 10', especially of anything substantial, you're going to have to start building scaffolding and putting it up and taking it down. Block and tackle rigs, etc. That's not going to be fast. Heck, logging your forest isn't going to be fast either (without chainsaws, steam-donkeys or bulldozers/tractors). Nor is evening up your trees, so you don't leave climbable outsides, or chinks inbetween them. You're going to have to drag your trees from further in the forest to your perimeter line. At around a 1' in diameter, figure you're going to have 20 to 40' lengths, and need ~12 per 10' in height (trees aren't parallel). ~5468 trees you're going to need to cut down for a 10' high fence. ~20m for an experienced ax-man per tree, assuming nice iron/steel axes are available - stone axes means a ridiculous amount of time more. How many axes do you have? Sharpening stones for each ax? New ax handles for the inevitable breakage? Around 30m to an hour for an unskilled worker. After which they're going to have sore hands, be winded, and the next one will take longer. You're also going to max out at somewhere around 6-12 hrs of (useful) work per day, of heavy manual labor, for unskilled people. You've still got to lop the limbs off, and drag it to your fence line, and/or lift it into position. How're you attaching these trees? I hope you've got a lot of rope. It might be possible to get many trees that're close enough that you can wedge them between alternating trunks. That will take a fair amount of surveying and planning. Btw, the number of trees given is for a perfectly straight 5km - if you vary your line at all (in order to use existing trees as uprights for example), it's probably not going to be straight - so be sure to add more work. You could also use some felled trees as posts, and dig out a nice hole near one upright tree and put a post in, keeping your horizontals inbetween the two. Still going to need a fair bit of rope to be putting up each section. If you don't have that much heavy duty rope / chain available, you're only going to be able to put up each section one at at time. You've got 546 sections to do. Let's WAG it at 10 hours for a 10' section (even higher gets an even longer time) - that's 227.5 days if you've only got one rope-set. You'd be better off spending some of your time making rope / chains for starters if you don't have enough. Also, remember that logging, especially old-school logging, is one of the most deadly professions. And even more-so for amateurs and for people who're working under stress; tired and fearful. They tend to make even more mistakes. Expect to kill a number of people in putting up these defenses. Old school trenching (shovels, etc) is even more labor intensive, backbreaking, and not very effective at keeping animals that can climb / leap out. It'll work on horse-like monsters. But not so great at anything else. If you've got the proper tools and horses, you can make some stuff which will move ground faster than shoveling. Might be worth your time to spend it building that equipment, then get working on trenching. But that's also going to be determined by your soil. Got clay? Some clay is next to immovable. As is bedrock. They even have trouble dynamiting that clay out here. It just laughs at jack-hammers. I can only imagine trying to go after it with a pick and shovel. Are your monsters afraid of water? Would a moat work? Redirecting water to cut a trench would be much more effective, especially if you've got height differential to work with. You only have to survey and cut a nice starter trench, then start dumping the water through. 5km may be a little long to expect the height differential to continue working, however. I know you can easily get 500' to clear with a reasonable head of water. [Answer] > > a ~5km barricade > > > I'm assuming you mean a circumference of about 5km (not 5km tall!) > > they do have numbers and stamina > > > It matters exactly how large their numbers are. Suppose you have 5000 people. They can all link hands and spread out into a big circle with each person about 1m apart and you then have your 5km perimeter. Each person only needs to deal with a 1m defensive line in that case, either by digging a trench or erecting a wall. > > The humans are resource poor, starting from scratch (wood/stone) > > > If you want a wall made of stone, you need to have a pre-existing stockpile of stone & mortar etc, or your people are going to have to mine it, which they can only do if they already have decent picks, hammers and other stoneworking tooks. I'm taking it from this statement that your people don't even have the resources to begin a quarry so this is ruled out. If you want a wall made of wood, you also need a pre-existing stockpile of logs, unless your humans are going to go logging in the exact same forest they're trying to stay away from because it's full of monsters. Unless they already have the weapons to defend themselves on these sorties (which would undermine their motivation for running away anyway) as well as the axes, ropes etc necessary for a productive logging mission, this is also a no-go. A trench, on the other hand, can be built immediately with your bare hands. Obviously a shovel makes things a lot easier but it seems like your people are desperately struggling for survival so they'll hunker down for a few days scooping dirt if that's what they have to do to be safe. If they have a water supply to turn it into a moat that could make it more effective (some animals would jump a dry trench but not risk drowning if the same trench is full of water). Water will also make it seem a more formidable defence even if it's not that deep. The disadvantage is that the sides may collapse and turn it into a smooth depression in the ground which can be walked in and out of easily. However, you also said this: > > monsters that live in the forest > > > which makes me think the most efficient defence for them would be simply to migrate away from any forests/cause massive deforestation in whichever area they choose to settle in by burning the whole thing down. Once they're living on the (newly fertilised) land near to recently destroyed forests, they can send their bravest defenders forth to set fire to other forests nearby and keep fighting back against the monsters' habitat. Eventually a few thousand years will have passed and the humans will start feeling concerned over the endangered species whose habitats they've destroyed, having completely forgotten that they used to be such terrifying deadly monsters. Kinda like real life, actually. [Answer] [Abatis](http://en.wikipedia.org/wiki/Abatis) - you can do it by cutting trees in certain pattern, and leaving them in place. No digging. Abatis substantially slows attackers, and they provide some protection for defenders. ![abatis image](https://upload.wikimedia.org/wikipedia/commons/d/df/Giant_abatis.jpg) But you will have hard time to protect 5km defense line - you will need thousands of defenders. Better off, use some naturally protected cliff, and build defensive trench on narrow area where approach is possible: [Hill fort](http://en.wikipedia.org/wiki/Hill_fort) BTW, cutting trees for such abatis is much faster than digging trench and building a barricade. Con is that abatis slows also movement of your own forces. Any engineering is like that - it is all about compromises. [Answer] This is one of reasons why humanity started from cave: What keeps them at this specific location? It ain't get better in other place, because monsters are everywhere. Yes, true, but it does not hold you back to go uphills. Go to cave, where you have to defend only small place (entrance to the cave) and it evens out the numbers pretty fast. So, other tactics could simply be: Find easy to defend place ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Closed 6 years ago. * This question does not appear to be about worldbuilding, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). * You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). [Improve this question](/posts/83116/edit) In a world roughly like ours, I have $millions per year, variable, in illegal income that I want to launder through a legitimate business. 1. I want to be able to scale the business up and down to fit cash-flow over months/years, 2. obviously I want to not waste too much in overheads (this is a lower priority), but it is critical that 3. if the authorities start to ask where the money ultimately comes from, the question can be plausibly answered or else be innocently unanswerable. The most obvious business front, to me at least, seems to be a casino. (Arbitrary amounts of anonymous cash comes in, arbitrary amounts similarly paid out.) Another idea is something like diamond mining,(assuming I can easily and anonymously buy rough diamonds for cash), but this less preferable because it takes a large upfront investment. What other businesses/industries are well-suited to this task? [Answer] Give me that Old Time Religion Churches are your answer. Start a religion so you'll be tax exempt. Any real donations you get swap with the blood money, which then goes to actual charity work, building homeless shelters, food drives, etc. You'll generate good will, clean your money, and who would suspect? Plus, did I mention tax free, in the US at least. [Answer] Anything that launders money is going to make it look like legitimate income; so generally speaking you are going to have to pay taxes on it if you do this in the USA. There are better places to do it -- but a good and scalable way of laundering money is just through the use of legitimate casinos, sports books, etc. You will be playing the odds; you need an honest vendor (like a Vegas casino) and bet (yourself, or through flunkies) on the close to even bets. The casinos take cash, even stacks of hundreds, and give you chips. Put the money through the 50/50 grinder one time (pass/nopass on the craps table is the closest I think). I've seen \$5000 on the pass line. I have also seen \$10K bet on a single basketball game. The house edge is somewhere between 1% and 5%, a more than reasonable fee for laundering. On average you end up with what you began, minus that fee. But in chips. Which you can cash in. But you have to think like the casino itself: A big loss is not a big deal, you will balance it out in the odds in the long run. So the business you are starting? Professional gambler. The con is, you pretend you win more than you lose. If anybody asks where the money came from, you don't know, you've had it for as long as you can remember. Nor are you obligated to keep records of where you gambled when, or how much you won or lost: You may have to pay taxes on your fake "winnings" at the end of the year, but you are not required to provide any details of where or when you won it: Just that you won it, and it exceeds the taxable amount. The point of laundering the money is so it cannot be traced back to you. At least in the USA, if the money is not marked or traceable by serial number, then you can just [declare it as income](https://en.wikipedia.org/wiki/Taxation_of_illegal_income_in_the_United_States) and pay your taxes: The Fifth Amendment protects you from having to provide any specifics on how the money was acquired, including if it was illegal. Another reason to launder it is to have a front, so no particular scrutiny falls on the criminal, but the professional gambling angle would cover that. [Answer] For your fictional setting, take some real world money laundering concerns. I trust that this is fictional, otherwise you'd be stupid to ask some random amateurs on the web ... * A business which deals very much in cash. Lots of small payments, so it can be explained why there are few card payments. A real estate broker would have problems because most money moves by wire transfer. A small grocer would be better, except for the next point: * A business where much of the value is added by manual labor, not by resale of goods and services which should have come with a paper trail. So instead of the grocery, where cash income must be balanced by real goods being moved, make it a hairdresser where workers bill fictional hours for fictional customers. * Don't put the business in a back alley. To explain the high cash flow, it needs to be on high street. If the cops start a stakeout to actually count customers, presumably you'll notice. Alternatively, place bets on non-rigged sporting events where the odds are roughly predictable. On the long run, over many modest-sized bets, the losses will remain affordable. [Answer] # Open a bank The best way to hide something illegal is to mix it in with something very legal. Essentially, you're mixing in a small amount of illegal items with a large amount of legal items. We can apply this principle simply enough. It seems that you have a large amount of money, probably in the form of cash. Where can you find a lot of cash? In a bank. Therefore, the simplest choice is to open a bank. Wait a while and accept plenty of legitimate accounts from ordinary, law-abiding citizens. Then all you have to do is set up a bunch of smaller accounts; this is called [smurfing](https://en.wikipedia.org/wiki/Structuring). Better yet, use a large system of agents - unknown to each other, known only to you - who open accounts in their own names. Put in a small bit of legitimate money, then add the illegal money, distributed widely. Each agent keep some of the money, and you keep some. Everything looks legitimate, and if one agent is caught, it may be hard to find the others. This does open up plenty of possibilities down the road. The repeal of the [Glass-Steagall Act](https://en.wikipedia.org/wiki/Glass%E2%80%93Steagall_legislation) allowed investment banking and commercial banking to come together again, so you might be able to use the funds for legitimate investments through your bank. [Answer] The best (IMHO, of course) way is to set up one or more companies working for the State, mainly in construction and maintenance. You can easily win contracts bidding lower than other "legitimate" companies because you don't really want to get money from there, You want to pay with "black money" as much as possible, while getting back very clean money directly from the mint itself. Viability of this scheme depends on how strict controls are on the way You pay Your workers, but in most places they will accept a steady trickle of "tips" not showing in official registers (and they know they would lose a lucrative job if slip). AFAIK this is actually used in many, very real, countries. [Answer] # Rock Band. Grab some random musicians/singers. Throw together a band. Become their manager. Bands are expected to have a messy economy. Books, what books? We have this suitcase full of cash. Not sure where it came from. Probably the place we played last week. Or was it this week? Springfield, I think, not sure which state. [Answer] Anything where lots of untracked money goes in is a suitable business, better yet if the actual work of the front company can be hidden away. A good example is the Breaking Bad series (if you haven't seen it, do so :-D ), where the main character, Walther, uses a car wash as a money launder for the money he earned on his & his partner's methamphetamine sales. A Car wash is potentially a good front, as you can easily pad a few extra customers on the monthly reports. Nobody (not even the IRS) can prove or disprove (without constant supervision of the front business) that laundering is taking place... Now, in any case, you'll need clean money to start the business (eg. a bank loan, or any clean income source.), and you'll need the following: * A person to run the business day to day * A number of people to come in with dirty cash * A way (or a number of ways) to have the dirty cash flow into the register (eg. useless car paraphernalia, fake antiques) and possibly a way to recycle these wares. * To attrach REAL customers (the more the better, in order to hide your own "customers") * A location where REAL customers will visit (Opening a massively successful carwash in Bumfuck, Indiana (population: 3) will most probably turn on a light at some of the Acronymic Agencies out there) * A Scapegoat (Your Plan B) We'll use Walther White's car wash as the first example: 1. I want to be able to scale the business up and down to fit cash-flow over months/years, Most businesses, including before mentiontioned car wash can scale up or down... In this case, you can open other departments elsewhere. This is relatively easy with, say a car wash or a pawn shop... You can upscale or downscale your work force or warehouse as you go along. With a casino, this is more difficult, not only do these places have A LOT of overhead (security, teller and dealer pay, not to mention power and operatin costs), but you cannot scale the business in the same way (you always need security, tellers and dealers for the business to run) However, there's no way to do this quickly without waking suspicion... crooked or not, a business needs to be handled with care if it's to be successful. 2. obviously I want to not waste too much in overheads (this is a lower priority), but it is critical that Again, this is a matter of common sense. At best, you need to have your business going well, or need to get there quickly. One way is to invest in a business that is already going strongly, but here you'd have to aim for complete ownership. A popular way is to buy up assets and warehouse stock from businesses that have filed for bankruptcy (which can be done quite cheaply), and opening something new from that. A third way is to "buy" permission to use an existing operation from another crook, however unsafe this may be. Walther's car wash employs only his wife (Skyler) and a few guys for customer service. Most supplies are bought bulk and are relatively cheap (car soap, water, car paraphernalia) 3. if the authorities start to ask where the money ultimately comes from, the question can be plausibly answered or else be innocently unanswerable. Any business where most people use cash for their transactions, you can get away with "most our customers use cash". Cash CAN be tracked (provided coins/notes have serial numbers), but you CANNOT track everybody along the chain like you can with account transactions or credit cards. As long as you process the cash normally (write it down as customer sales, and go to the bank with it as normal (ie. NOT suddenly depositing $500 grand for your little shop) and filing it properly with the IRS), the IRS & co. cannot prove or disprove where the money came from... In your case (millions of dollars a year), your bunch of criminals would most likely have a small "network" of assorted money-laundering businesses. A variety of different businesses makes the system stronger; not only can they help with masking the illegal money traffic by conducting normal trade, the system will also be less susceptible for being shut down (like a chain of casinos or car washes). A varied portfolio of front businesses (especially when owned by different people) also gives your organization the possibility of using the locations for criminal purposes (say, for cooking meth), and another trump card for others in the network ("I didn't know") (ps. not meant as an education in money laundering, only giving OP some options to work with) [Answer] Hotels, motels, etc. Other businesses which create or resell a product, have a long paper trail of having to buy the ingredients, so it is easy to inspect how many products they could have manufactured. However, if you have a large hotel, who can tell if 10 people or 100 people slept there last night? Yes, guests have to be registered nowadays, but it is easier to fake that than to fake shipments of raw materials. [Answer] A business that has high flow through and small profits would be ideal. The additional money would look from an accounting perspective as just a slightly better profit margin. Put a little work into fake invoices so there is a paper trail for the money and then do the tax accounting honestly and it would be hard to detect. Even better if the business is largely cash, so having sackfuls of money show up wouldn't be strange. I read a crime novel where the bad guy used a car repair place in a poor neighborhood as the vehicle to launder his drug profits. From the outside, the place just looked like a well run small business that had built a loyal clientele. Actually the car repair part was not that great, but the drug profits were easy to surface through it. After that place got too small to deal with all the cash, the bad guy bought a car dealership. [Answer] # International money transfer shops and coffee shops. Both handle large amounts of cash, specifically for international transfer with not a lot of questions asked about where the money comes from or where it's going. Unfortunately the police also know this and they used to get shut down as fast as new ones sprang up in their place when I was living in areas that considered it part of the traditional business. [Answer] Pay illegal workers. Have a legitimate business where labor makes you money; like construction, resource extraction or menial service. A certain percentage of your workers will be expected to be illegal and to avoid official counts. Pay optionally in cash by the day and under report how many workers you have by about the same amount. On paper it just looks like your legal workers are efficient. This might allow you to take advantage of the traditional profits of using illegal workers like underpaying, lack of benefits and lax worker condition standards. This also gives you a cover of sorts since there is an obvious reason for a money discrepancy (covering for illegal workers) that is often somewhat accepted in those industries. [Answer] Any cash only business would be a great way to start. You could follow the car wash example posed by JamesD but any business you could automate would work as well. As a real world example I live above a launderette... wait I promise this is going somewhere! The launderette is un-manned and automated, people walk up to a control point, put in coins and the washing machines start. I believe my landlord owns around 20 similar outlets around the city I live in and each one requires one staff member who comes to un-lock in the morning and cleans and locks up in the evening, probably paid minimum wage or near enough for 2-3 hours a day. The cash is collected by the landlord on a weekly basis. A similar business model spread over a number of sites could easily be used to launder money into "legal" income, sure there would be set up fees but once they are paid you're pretty much set up to just get the income provided by the business alongside your laundered funds. As a rough example to estimate the viability of this: 1. Each spraff Laundry co. location has 12 washers and 12 dryers 2. Each washer or dryer costs 6 USD to run for 1.5 hours 3. spraff Laundry co. locations are open from 0600 to 2200 4. The launderette is open for 16 hours a day, with the machines running 1.5 hour cycles you can get around 10.6 cycles per day out of each machine. Let's round down to 10 to make things easier. 5. 12 washers and 12 dryers each running 10 cycles a day gives 240 cycles per day total. 6. 240 cycles per day \* 6 USD per cycle = 1440 USD per day for one launderette. 7. Say you have 20 locations that gives you 28 800 USD of potential income per day. 8. Multiply by 364 days/year and spraff suddenly has 10.4 Million USD per year of cash revenue which he can explain in whatever way he wishes. I think this could be a very viable solution to your laundering problems, it'll clean your clothes too. [Answer] To reuse am idea how about a car wash <http://breakingbad.wikia.com/wiki/A1A_Car_Wash> Cash payment, invent customers and push the money thorough that way :) ]
[Question] [ I've lately been looking at a lot of War of the Worlds remakes/spinoffs, like the 2005 film, the 2013 mockumentary The Great Martian War, and of course, the tabletop game All Quiet on the Martian Front. While looking through all these awesome stories and scenarios, one question has been bugging me for a while. Why exactly ARE the Martians invading? (This is not a question about the novel/movies/etc. It's a question about Martian invasions such as the one depicted in this story. Why would they do that?) Before I get into my qualms, lemme present you with some research I've done. The original story was initially written in the late 1800's-early 1900's, by the brilliant H. G. Wells himself, as a commentary(?) on the imperialistic mindset of certain countries at the time. In the year 1913 (which is roughly when the story could take place), the world was on the verge of war. Europe was growing more divided as Britain allied with France and Russia, and Germany partnered with Italy and Austria-Hungary. An arms race had begun, increasing European military spending by 50%, and the Ottoman Empire was fracturing more and more. All it needed was that one little push to send everyone biting and kicking each other. Now back to War of the Worlds. In all the sources I'm finding, the reasons for the invasion don't pan out, or at least seem pretty dumb. Several play with the idea that the Martians are harvesting humans for food. However, as we all know, they die off from Earthly diseases, so collecting humans which are full of Earthly germs would be kinda dumb; after all, who knows if humans are safe to eat if they live on another planet? Obviously, this sounds more like a paranoid xenophobic fear than a realistic cause for War. The mockumentary (spoiler alert) played with the idea that the Martians wanted to collect the metal and resources humans had put into their military, and used the war as a means to collect. But there are plenty of better sources of metal in the solar system. Heck, the asteroid belt's right there, open for harvesting, and it won't try and shoot you back. So no dice there either. And as for the Martians being afraid of human destructiveness, keep in mind that this was the early 1900's. The first atomic bombs wouldn't be tested for another 20-30 years, and airplanes weren't even a thing until just a couple years ago. So what would a couple million humans do to Martians which already had HEAT RAYS AND INTERPLANETARY TRAVEL down pat? So I now ask you...what WERE the Martians thinking? Empires only expand because of good reasons, whether food, resources, the completionist tendency to fill in all the empty spaces in a coloring book, or something. What would prompt aliens from a desert world like Mars to send a dozen or so War machines on what would likely be a one-way trip to another world - a world with a radically different biosphere and gravity, mind you - and then start attacking the native population? [Answer] It is worth revisiting the vision of the universe as seen in the late nineteenth century when Wells wrote The War of the Worlds (1898). In that view the planets of the solar system formed from a cloud of gas and dust. This is the so-called Laplacian nebula hypothesis, not unsurprisingly formulated by the Comte de Laplace, mathematician and astronomer, it postulated that the planets condensed out of the nebula, with the outer planets forming first. This means that the inner planets formed last. So the further you go out from the Sun the older are the planets. Mars by this reasoning is older than Earth.\\ Using this cosmological framework Wells speculated that Mars is much older, growing colder, its resources running out, and all in all it is a dying planet. The canny Martians finding their home planet is going to wrack and ruin decide to dispatch an invasion force to seize the Earth by superior technological force and make it the new abode for Martian life and intelligence. As a side-note: Because Wells had studied science, in particular zoology, he took pains to make his Martians non-human creatures unlike other writers of imaginative romances who were his contemporaries. Although Wells wrote a speculative article called "Man of the Year Million" which suggested our far-future descendants might become creatures that were not too dissimilar to his Martians. There is more than a hint that the Martians are what we will become, and despite the better technology they weren't much improved ethically. The dying planet rationale is often used to justify alien invasions by science-fiction writers. This is a big improvement over writers who seem think coming to steal all our water would be a great idea for an invasion. The purpose of this answer is to show what was the reason within the conceptual framework of the late nineteenth century that prompted and shaped the way HG Wells wrote about a Martian invasion. His novel reflects the science and politics of his day. \\: Also, Venus was considered in the Laplacian model to be a much younger planet than Earth. This the reason why the planet Venus was often portrayed in early to mid-twentieth century science-fiction as a world of primeval swamps, jungles and dinosaur-like monsters. Basically as an exotic version of the prehistoric Earth. [Answer] They need the planet ready for colonization as soon as possible. Back when the 2005 War of the Worlds film came out, a friend and I tried to puzzle out a reason for why the aliens (not going to call them Martians, as they apparently were not Martians in that film) behaved as they did, and what we came up with was the following: Tens to hundreds of thousand of years in the past, the aliens scouted Earth for eventual terraforming and colonization. THey seeded their construction equipment, designed their biological components of their terraforming technologies, and got ready to begin altering the planet to their specifications... and decided not to. Perhaps funding, or political will, or something else ran out, or perhaps they got involved in an interstellar conflict with another species. For whatever reason, they decided not to go through with it, but left things in place so that they could be reactivated if the need arose. Cut to some time before the invasion. Something has gone terribly, horribly wrong for the aliens in question. It could be that the interstellar conflict has gone much worse for the aliens than they expected. The aliens that come to Earth are refugees, fleeing some kind of disaster, political, natural, or interstellar. Or maybe it's just a poorly-organization trying to make a relatively-quick profit. At any rate, they need a new planet, and they need one ASAP, and they don't have the resources to do everything properly. Someone remembers the records of the Earth project, and they look it up: The terraforming machines are already in place; the biologicals have already been designed. All we need to do is port a few scientists in to get things started and... Damn, there's a technological intelligent species already there. Okay, we can deal with this. We'll jury-rig the construction equipment into war machines and send the tripods after them. The landscaping rays will work fairly well against their primitive technology, and once we've killed them all, we can seed our biologicals and start reworking the biosphere and... Damn, the Red Weed is not working properly. It was designed tens of thousands of years ago, for a different environment, and to be tended by a full complement of skilled ecoengineers. We can't completely redesign it, it would take too long. Okay, we can work with that too. We don't have all the knowledge and expertise we had back when the project was initially planned, but we've got some texts and we should be able to jury-rig its genome so that it can thrive on the Earth that is instead of the Earth that was. Also, since we're going to have to kill all these humans anyway, we can use them as biological feedstock once we manage to tweak the Red weed enough to -- Damn. Tweaking the Red Weed to run off human feedstock allowed a native pathogen that evolved since our last surveys to interact with the Red-Weed genome and turned one of the symbiotic viroids that were in the Red Weed into a contaigion. Once we would have spotted by the full complement of ecoengineers we don't have, or by the ones we did have, if they'd had more time to do their job properly. And now it's gotten into all the foodstocks, and infected the entire advance party, and they'll be dead in cycles. This was a fiasco. Quarantine the world, and check on how things are going on the other abandoned terraforming projects. [Answer] They're here because of massive, [global climate change on Mars](https://en.wikipedia.org/wiki/Climate_of_Mars#Martian_paleoclimatology). It's possible that the Tharsis Mountains on Mars used to emit massive amounts of H2O and CO2 into the Martian atmosphere, potentially even covering nearly the entire planet in over 100 meters of water. But, the volcanoes are much less active now, and the water doesn't have a proper water cycle like on Earth. So, the Martians have been slowly retreating with the poles, following the small remaining amount of water as their world slowly becomes inhospitable to them. But, they're certainly not technologically inactive. Oh, no. They've got a space program with one single goal: fly to Earth and forcefully colonize it. We're even making it more attractive to them by increasing CO2 atmospheric concentrations. As soon as they get here, they'll probably start burning down the jungles to accelerate atmospheric CO2 increases. And, of course, you can't let those monkeys with delusions of grandeur ruin your plans. So blast their population centers until there's only small pockets of resistance remaining. [Answer] Assume that the planet Mars is an abode for intelligent life and it has an ancient civilization. Resources are sparse, the temperature low, the atmosphere is pretty thin, and the surface is uninhabitable. Recently probes from the third planet have arrived on the surface and in orbit around their home world. The Martians have had interplanetary travel for millennia. Their laser technology and portable power generators make formidable weapons. Nuclear weapons are easy too. Do these humans represent a threat to the Martian way of life and peaceful interspecies coexistence? Of course, they do! Consider this, Earth is a planet dominated by a species of primate whose social and political institutions are mainly mobilized to wage large-scale organized conflict. They are on the verge of developing interplanetary travel. Yes they have lasers, but these are far from weapons-grade laser systems. Their nuclear weapons technology is a potential threat. Their global culture is one of runaway resource consumption. Soon they will the invade the solar system and begin strip-mining asteroids and establishing settlements on its moons and planets. Earth is the fifth biggest planet in the solar system. That's right, Earth is a giant planet solar system wise. The Martians do not visit Earth because of its high gravity. Earthlings, once they have sufficiently developed interplanetary travel, will be able to access all the planets in the solar system with the exceptions of the gas giants. This means Earth and Mars may find themselves in competition for resources and living space on the moons, asteroids, and planets. Earthlings will be able to occupy and visit Mars while the Martians won't be able to do the same on earth. Admittedly the Martians will have developed a mature environmental friendly technological culture many, many millennia ago. Now they are threatened by a cancerous incursion into their civilized and highly cultured solar system by primitive tribes of under-educated apes. The Martians are not fools. They know their biology. This is evolutionary competition. The Darwinian struggle writ large between technological species from two different planets who will now be competing for the same set of resources. They will "slowly and surely draw their plans against us." This is a war for survival. Them or us. Two sapient species with interplanetary capable technologies cannot survive together in the same solar system unless they have both learnt the art and science of mutual cooperation and tolerance across species. Each species will have weapons and technology that can exterminate the other. If the species with the technological advantage truly feared and felt threatened to the point that it might be extinguished by its potential adversary, then the temptation to strike first could become irresistible. In which case, let the Martian invasion commence! May the better species win! PS: Wells' Martians were the product of the late nineteenth century, these early twenty-first Martians will have superior physical and biological technology. No microbe, no matter how humble, will lay low these Martians. Also, gravity was no obstacle in 1898, the Martians wore their Fighting and Handling Machines like mechanical exoskeletons now with AI upgrades and better telemetry Martian Fighting Machines can be partially controlled and directed from orbit, allowing the Tripods themselves to do the rest with local decisions. [Answer] Empires don't have to invade for external reasons. Their own momentum and the need to employ their military assets can be a reason in itself. The Romans didn't always need to keep expanding, and they conquered peoples who were absolutely no threat to them. One of the reasons they did this was to employ their military and gain glory for elites. So quite often they picked fights for no better reason than that. Timur-i-Leng did the same, he went on an uninterrupted cavalcade of victorious conquest for no better reason than to employ his army. Ghengis Khan picked fights wherever he could, his descendants unsuccessfully invaded Japan twice for no other reason than because it was there and unconquered. Alexander the Great was pretty much the same, he'd beaten everyone at home, so he headed abroad. Cyrus the Great, Phyrris and uncountable Asiatic, Middle Eastern, African, South East Asian, Amerind and even Polynesian outfits did the same. Many of them even massacred populations who hadn't resisted. [Answer] We've all seen multiple films where the "evil aliens" want to steal <natural resource> from earth, and I agree, it's an absurd premise when you can readily collect them from a shallower gravity well someplace else. I suspect that most empire building objectives, while realistic when Wells wrote the original, would seem equally silly in the light of modern scientific knowledge. One possible justification for war, however, might be as a first strike to prevent us from invading them. Consider: * [Le voyage dans la lune](http://www.imdb.com/title/tt0262883/?ref_=nv_sr_1) came out as a film in 1902, and [Aelita: Queen of Mars](http://www.imdb.com/title/tt0014646/?ref_=nv_sr_1) came out in 1924. We didn't have the ability to transmit them electronically, but perhaps the Martians' sent an Earth probe to secretly collect data, and it pulled a copy of the film. They might believe it was a documentary, and think we already had space travel. * Earth seems to have been in a perpetual state of war for centuries; it seems likely that any rational species would be concerned about what we'd do. Early SF horror or dystopian films might be scary, but historical films (e.g. [Battleship Potemkin](http://www.imdb.com/title/tt0015648/?ref_=nv_sr_1) and [The Big Parade](http://www.imdb.com/title/tt0015624/?ref_=nv_sr_1) depict how inhuman those earth people can really be. * Photographs of early cannons might be misinterpreted to indicate a massive space race already underway. The fact that they can't see us doing it might even be misinterpreted as "stealth" capability -- and the enemy you can't see is often scarier than the one you can. If you want to stay close to the original H.G. Wells story, however, you may (spoiler alert) need to consider that the Martians' understanding of biology is substantially inferior to their understanding of physics. How can they travel in space and not be able to maintain biological isolation once they get here? Clearly they didn't think it might be necessary. General naiveté (as used to justify the points above) might suffice, but we might also be warring against a culture that has just come out of a scientific dark age of some sort. [Answer] If I were to theorize I would say that it would most likely be due to a couple things. 1. Martians had known of us for a long time and always planned on cleansing the planet. They had never gotten around to exterminating us, then they saw signs of early technology that might give us potential to discover and kill them. 2. A regime either governmentally or religiously that was in favor of leaving earth alone changing due to increasing fear that the earthlings would rise to power and "come for us next, once they get bored of killing each other" Beyond that I would say it is pretty subjective. I haven't seen all of the versions, but as far as I can remember, I don't recall themselves ever declaring that Mars was their home. I feel as though it could be entirely possible they are from somewhere else entirely and stumbled upon this planet rich with resources. The hard part is, we cannot really know what drives them. There are so many illogical things humans do that make no sense when you are an outside observer, but introspectively and evolutionarily they make perfect sense. [Answer] The biggest valuable thing on Earth is work labour. If you can harness that, you have really big basement for nearly anything. Same principle was after a lot of wars here on Earth. Also the same is why we domesticate animals. Basically... Slaves If they can manage to rule us, they will have really big source of energy, work and we will be "self-servicing" damaged "parts" of the system by new babies. All needed is just to collect the revenues. Then there are another considerations, as "just get resources", or eliminating us as a threat. Or they just had a bad day. [Answer] The 1950's movie starts with a voice-over that explains the Martians have been watching us from afar and are envious of us. Clearly they aren't envious of our technology or culture since they treat both with disdain. That also makes it unlikely they were afraid of us (not even of nuclear weapons). That basically leaves our planet or resources as their goal. Since Mars is a barren desert that's not far-fetched which only leaves the question of which resources they are envious of. It can't be something abundant on Mars, in space, or on other planets or moons since they have access to those places already. That really just leaves rare earth minerals, air, water, biological materials or environmental factors. I would presume then that they intended to terraform (as in the unmentionable 2005 movie version), farm or otherwise harvest our biological resources. Whether they planned to do that themselves or use humans as plantation slaves is unknowable. [Answer] Reason 1: --- Their technology is advanced but not THAT advanced. They have vastly superior military resources but their replicator technology hasn't really taken off and they need large amounts of biomass to turn to food if they want their race to survive the coming century. Reason 2: --- They don't really need to invade the whole planet but only a small part. But they have monitored us and know that an invader would be what finally unites the humans. So they need to invade us globally and quickly to prevent an effective counter attack. Reason 3: --- They have been monitoring our progress and fear we might become the superior power in the Solar System/Galaxy. So they nip us in the bud. [Answer] Why posit aliens are always doing things for intelligent reasons? Maybe they're religious fanatics. Maybe their leadership needs to divert attention to an external threat to distract from their internal issues. Maybe they're violent xenophobes and this seems like a good idea to the general populace. Many of our own wars, including by the more powerful sides, are driven by terrible decisions (usually with business or industry on the side figuring out the best way to cash in, albeit for themselves, even when you look at the total gain/loss being a bad deal). The biggest limit to this when it comes to space is practicality, which mostly depends on hard sci-fi premises. If you go with the soft science fiction rules around most alien invasion narratives, which make it, honestly, not much harder than any other invasion and conquest, yeah, it will happen for about the same level of reasons. [Answer] Martians were divided into many fractions hostile to each other. The martian leaders were desperately trying to find a way to pacify Mars. Of course historically the best way to unite your own people was always to have a common external enemy, but where to find that if you tried to unite the complete planet? Finally they found the solution: Their astronomers reported that an intelligent race on Earth was starting to develop technology. That made those Earthlings a suitable target of spreading fear about: Surely they'd soon attack the Martians. Well, OK, realistically, they'd need another couple of centuries until they could even think of that, but hey, the Martian masses don't need to know this. So the propaganda machines were ramped up, convincing all the Martians that humans were already preparing to invade Mars and kill all Martians. Some documentaries about wars on Earth were certainly helpful (especially recordings of the nuclear bombs), and when the Earthlings started to send probes to Mars (which fortunately could be manipulated so that they sent fake images of a dead planet back to Earth) this was used as great evidence that the invasion from Earth was bound to happen soon. The tactics worked: All Martians soon stopped their hostilities against each other and started working together on their plan on a preemptive strike on earth. But of course they needed to have the common experience of a Martian victory over Earth in order to ensure that Mars would remain united even after the threat was gone. The Earth population of course would have to be exterminated, in order to keep under the rug that in reality they were far from able to attack Mars. Well, as we know from the movies, that plan didn't quite work out at the end. [Answer] Martians like Humans probably don't need a reason to travel over a "large expanse" and try to colonize, exploit, rape, plunder whatever they find on the other side. And realize that even if they are just 100 years more advanced than us, they can kill us quicker than the conquistadors did to the native people across many different continents on Earth. The Earth is a prize for any space warrior races, lots of resources, sexy women and bunch of idiots that keep fighting with each other instead of defending it. Consider this, a spaceship with the equivalent of just 500 nuclear warheads detonated at 5000 feet over every major city would kill the vast majority of everyone on earth, would leave every nation governmentless and its people struggling to survive. In about 2 or 3 years the radiation, disease, and lack of food would kill 90 percent of everyone left. The actual radiation would subside very quickly. And the aliens would have a slightly used planet for their use without so much of a fight. The big problem with all WOW and Independency day is that they assume that the aliens are like Americans and Russian in Afghanistan, having to come down to give us a fight. No, they are just going to nuke us from orbit. It would take a few hours to kill 50% of the people on Earth. No advanced technology needed. ]
[Question] [ Specifically, could new planets form around a previously destroyed star? (Think of it like a phoenix.) If so, could the potential sentient life detect that their star previously exploded? [Answer] If by explode you mean go Supernova, then no. Emphatically, no. Most stars don't explode at their end of life...they turn into a Red Giant, then a White Dwarf, then they burn out. This is a one-way street. There are, in general, two main ways that a star can go boom. Either you can have a Core Collapse (type 2), which is when a massive star's core destabilizes (for one of several reason), collapses--creating a massive energy surge--and it detonates. The other is when you have a pair of stars...one a white dwarf, the other large...and the white dwarf is stealing matter from the larger star (Type 1a). Eventually, it steals enough matter that it exceeds the Chandrasekhar limit, collapses, and then explodes. (there are one or two other ways it can blow, such as white dwarfs colliding...but they are rare occurrences) When a star goes Supernova, the resulting explosion is the second most energetic type of event that we have ever recorded, exceeded only by colliding black holes, and the energy they released was mostly gravitational in nature. The luminosity of an exploding star can exceed the luminosity of a galaxy. Betelgeuse, a red giant star that is 640 light years away, is nearing the end of its life and scientists expect it will go out with a bang. When it does, the resulting flare of light as observed from Earth will be as bright, or brighter, than a full moon. In a 'What-If' XKCD article, Randall Monroe spoke with a Physicist friend who said "however powerful you think a Supernova is...it's more powerful than that." If you compare a Hydrogen Bomb pressed against your eyeball and a Supernova viewed from the distance Earth is from the Sun...the Supernova will deliver more energy to you by 1,000,000,000 times ([ref](https://what-if.xkcd.com/73/)) Finally, the surviving remnants after a Supernova depends on the type. A Type 1a supernova leaves nothing behind but a rapidly expanding 'supernova remnant'. There is no star left behind for anything to form around. A Type 2 will form into either a Neutron Star or a Black Hole as the super-dense core of the star is left behind after the explosion. I'll get to why all of that is important in a second... The next thing to examine is how planets form around a star. In a nebula, gasses can reach a point where there is enough in one place to start to generate a gravity field strong enough to pull more gas/dust towards itself. This creates a cascading process where it draws more and more gas in towards itself, becoming more and more massive as it goes. It also starts to spin as this happens. If enough gas/dust accrues, fusion ignites and a star is born. The remaining gas and dust are strung out in a disc around the newborn protostar, and...now that the new solar wind and radiation pressure is pushing the dust away from the star to counteract the gravity pulling it towards the star...the dust is now a little more likely to settle into an orbit, forming a protoplanetary disc. During this time, it doesn't stop clumping, and the resulting smaller bits that accrete together are how you get planets. So, in order to get planets, you need that dust cloud for them to form from. So, to finally give the answer, let's bring all of this together. A Type 1 Supernova cannot meet your requirements: there's no star left for planets to form around. So that's out and only leaves a Type 2. A sufficiently massive Type 2 will create a Black Hole; those don't turn back into stars. A smaller one will create a Neutron star, but those don't turn back into normal stars either; if you add mass to a Neutron star, they collapse into a black hole. Black holes are obviously unfriendly to life, but neutron stars aren't much better. They don't emit a ton of energy, aren't very bright, and most of what they emit is in the form of blasts of radio waves. Furthermore, the insane forces involved in a Supernova produce a shockwave that has been clocked at moving around 10% of the speed of light that slams into all matter within the stellar system and hurls it away from the point of the explosion. This creates what we call a Supernova Remnant, which is a rapidly expanding cloud of super-heated gas and debris. A prominent one that we know about is Cassiopeia A, which is (as viewed from Earth) about 10 light-years across and is still expanding at a velocity of 4-6,000 km/s. The vast bulk of the matter in the stellar system will be ejected from the system. However, due to interactions between the matter, it is possible for some matter to not be ejected from the system. For clarity, this means that the matter ejected from the star with the explosion collides with planets, with other ejecta from the star moving at different speeds, and loses velocity. If it runs into enough other matter and loses enough speed, the gravity of the surviving core of the star (neutron star or black hole) overcomes its velocity and pulls the matter back in. Most of this matter will be pulled back into the remnants of the stellar core. However, it is possible for some of it to gain enough angular velocity to enter orbit around the stellar core (now a Neutron Star or Black Hole), creating a circumstellar disc. If there is enough mass in this disc, it is possible for planets to form out of it. Alternately, we have a few cases where it looks like the core of a companion star survived the Supernova and formed something vaguely planet-like. However, this does not change the answer with regards to anything living there, because neutron stars and black holes are incredibly lethal to life as we know it, pouring massive doses of ionizing radiation into the space around them. So, in summary: A Type 1a Supernova fails your requirements, because it leaves nothing star-like behind. A Type 2, at best, leaves behind a low-energy star that is very unfriendly to life, otherwise it leaves behind a black hole...and if material falls back into the low-energy star, you still get a black hole. In certain cases, planets may still form, but they will be uninhabitable unless you get into extremely exotic 'life' that doesn't operate anything like life as we currently know it. [Answer] Yes to the first, No to the second. Planets may in fact be common around neutron stars. [Debris from the supernova forms a circumstellar disk](https://en.wikipedia.org/wiki/4U_0142%2B61) around the neutron star and, although composed of heavy metals rather than light dust, is similar to the disk where planets formed around a new star so similar dynamics are presumed. Watching the process of how these planets form so quickly after the supernova is cutting edge astronomy. However, it's been known for 25 years that [pulsar planets](https://en.wikipedia.org/wiki/Pulsar_planet) exist. While [one such body](https://en.wikipedia.org/wiki/PSR_B1620-26_b) appears to have been capured from its companion star, in general they appear to have formed in place after the supernova. As for life, life as we know it could not exist under these conditions. Some exotic life like [hard s-f authors dream up](https://en.wikipedia.org/wiki/Dragon%27s_Egg) would be interesting to discuss on its own Question if it could be asked in a way that’s not “too broad” or “opinion based”. [Answer] A star that explodes sufficiently violently to destroy itself is called a [Supernova](https://en.wikipedia.org/wiki/Supernova), and they come in several types. Some kinds of supernova leave a remnant, in the form of a [neutron star](https://en.wikipedia.org/wiki/Neutron_star) or a [black hole](https://en.wikipedia.org/wiki/Black_hole). Firstly, a supernova explosion is so violent that all the matter blown away by the explosion will be moving above any remnant's escape velocity, so there's no possibility of the star reforming: that can't happen. It is possible that a black hole or neutron star could have planets remaining from before the supernova. Or rather, the remnants of planets. To get an idea of what a supernova will do to its planets, make a model planet out of butter or jello, and then apply a welding torch, enthusiastically and for several minutes. You might have a small crisped body left, if you started with a large one, but all life on it will certainly have died, and the planet will be much smaller than it used to be. It is just conceivably possible that new life could arise on such a remnant planet, although it's deeply implausible: the environment will be very hostile. If such life developed sentience and science, they might eventually figure out that their "star" is quite unusual and had exploded far in the past. However, there is a much more interesting answer. The Sun, Earth, and the entire solar system are made out of debris from one or more supernova explosions. The superheated gas blown off into space from a supernova can eventually form new stars, but note that this is likely to be several small stars, and there's no real way in which they are the original star. We know that we're made out of the debris of a supernova (or maybe more than one) because Earth has heavy elements like gold and uranium. A supernova explosion is the only [process](https://en.wikipedia.org/wiki/Supernova_nucleosynthesis) in the universe that produces such heavy elements, as far as we know. So you, and everything around you, are made of matter that has been part of a different star, which exploded. Which is rather cool. [Answer] There is no simple answer to your question. In a way, yes, exploding stars can (and do) create planets. And yes, sentient life can (and does, in our case) understand that their star exploded in the past. Yet, what guildsbounty has stated above is pragmatically correct. Let me explain. There have been three generations of stars. The [first generation stars](http://www.solstation.com/x-objects/first.htm) (also known as population III stars) were stars which were monstrously huge, even when compared to our sun (and our sun is a *seriously* gigantic object). They all exploded in supernovas known as [pair instability supernova.](https://en.wikipedia.org/wiki/Pair-instability_supernova) The flesh and bone (more like debris) of these dead stars later condensed to form second generation stars which were relatively rich in heavy elements (anything with an atomic number greater than 2 is known as heavy element in cosmology). Then these second generation stars died too, and their remains aggregated and produced third generation stars, one of which is our sun. So yes, we are literally stars. Our Earth contains large amounts of metals, carbon, oxygen, silicon, halogens and several other elements, all of which were formed in the core of a huge star, once. And this earthly dust forms our bodies, our flesh and bones, skin and blood. And we, being sentient species, know that we (and our Earth, and our whole solar system) is here as a result of a horrific stellar explosion billions of years ago. So yes, stars do explode and their contents later condense together to form newer, smaller stars, and planets. But so far as we know about supernovas, no planetary system is known to survive the violent explosion of its parent star. The shockwave resulting from the supernova destroys planets within minutes, leaving only dust and space debris. Later this dust and debris resettles to form newer solar systems, but the older, original planets do not remain and a star's remains do not add new planets to the older planetary system. Once a supernova occurs, the whole system is destroyed and rebuilt in the next few billions of years. [Answer] There is a caveat most people have not considered - what becomes of the stellar dust which was your star after the supernova scatters it to the galactic winds. Flung out into the interstellar medium, riding an immense and highly energetic shockwave, if this matter encounters nebular matter, it is likely to accrete and form new stellar masses, which in turn may form perfectly normal planetary systems. Indeed, most of the stars you see in the sky were formed this way; clumps of stuff smashed together by the shockwave of a dying ancestor. Part of their mass is composed of the baryons from the dead star, thus semi-meeting the requirement of being the dead star. Could this be detected? Yes, probably, depending on the structure of the interstellar neighborhood in which these inhabitants found themselves. If you look out at some of the nebula in our own galaxy, you can find clusters of similarly-aged stars which appear to ring an ancient supernova site. Such a structure could also be detected from within itself by one of those system's inhabitants. [Answer] One supernova probably won't be enough to make a new star but couple of them will make couple of stars. And for a planet to be habitable, it must be formed in such a situation. Our star is at least third generation star. So your idea of Phoenix star system won't happen, but a Phoenix cluster might work. This is basically the same answer as Youstay Igo, but simpler. ]
[Question] [ I am creating a story with wizards and a war between the medieval and the magician, but I liked the idea that this world was huge, and the different people lived a colossal distance apart, not just days, but almost years. Therefore, this world would have to be something like the size of Jupiter. However, as I did some research, I found out that very large planets end up collecting too much gas and also have other factors that make them unsuitable for life as we know it. That being the case, what can I use to make my huge world plausible? Should I just use the excuse of it being a fantasy world, or do I have to drastically reduce the size of the planet? [Answer] In a magical/fantasy universe then it's easy enough as you say to just explain it away using magic. There's no need even to go into details, but you can either say the laws of the universe work differently, or use a less direct explanation like saying for example that the planet is hollow (and held together/supported by the magic). In a true fantasy universe you can have the planet any shape you like, including flat. :) [Answer] If you are concerned about the size of your planet, you should consider why it needs to be that size. With low technology levels, it does in fact take years to cross the Earth. Crossing the Earth in days is only a recent invention. You can increase the distance covered by reducing the tech levels. After all, technology has brought the world closer. Inverting it would result in the reverse. [Answer] Similar to [March Ho's idea](https://worldbuilding.stackexchange.com/a/6971/2845), you can make the world Earth-sized but in the shape of a maze. Separate the paths by extremely tall mountains or oceans of acid, making it impossible to travel effeciently. To someone living on the planet, it will seem as though the circumference is far larger than it really is. For example, in the map below, green represents inhabitable land, while black represents impassable terrain. Assuming the map is of an Earth-sized world, the circumference will seem to be over 300,000 miles. ![enter image description here](https://i.stack.imgur.com/kGji7.png) [Answer] For example you can assume that the gravitation constant $G$ is smaller. Actually I think that chemical composition can be always tuned, but if a planet should be similar to Earth, gravitational acceleration $g$ on the surface should be similar. Thus, from $g = \frac{G M}{r^2}$ and $M = V \rho = \frac{4}{3} \pi r^3 \rho$ we get $G = \frac{g r^2}{M} = \frac{3 g}{4 \pi r \rho}$. So we need $G \approx 6.0 \cdot 10^{-12}$ m$^3$ kg$^{−1}$ s$^{−2}$ instead of 6.67 m$^3$ kg$^{−1}$ s$^{−2}$ — a little bit more than ten times weaker because the planet must be a little bit more than ten times bigger than Earth and besides the same and the equation gives inverse proportionality. Than escape velocity is, from $v\_e = \sqrt{\frac{2 G M}{r}} = \sqrt{\frac{8}{3} \pi G \rho} r$, 37000 m/s and this probably determines chemical composition — more light gases should stay. We have to assume that the planet is similar to Earth due to an improbable but not physically impossible accident or because it was created artificially, maybe using magic. We can also focus on correct escape velocity and composition. We determine gravity constant to obtain escape velocity like for Earth: $G = \frac{3 v\_e^2}{8 \pi r^2 \rho} \approx 5.4 \cdot 10^{-13}$ m$^3$ kg$^{−1}$ s$^{−2}$. Than $g$ will be 0.86 m/s$^2$, so everything would be lighter, but besides, similarity to Earth should be more plausible. Data used: * Jupiter radius is $r \approx 70000$ km. * Earth mean density is $\rho \approx 5500$ kg/m$^3$. * Gravity of Earth is $g \approx 9.8$ m/s$^2$. * Escape velocity of Earth is $v\_e \approx 11000$ m/s. This method should stay in the range of soft sci-fi, not hard, but also not totally crazy fantasy. [Answer] How about a "reverse" Dyson Sphere? An artifically created sphere-shaped world the size of Jupiter where the inhabitants live on the surface. The interior of the sphere may be hollow or contain just enough mass to ensure Earthlike gravity on the surface. Better yet, the interior of the sphere contains an artificial sun, somehow suspended in the center of the sphere, that allows inhabitants to live in a zero G environment (according to the [Shell Theorem](http://en.wikipedia.org/wiki/Shell_theorem) gravity is nullified at any point inside a sphere). [Answer] I would personally suggest that you make all landforms islands or similar, and getting from one land form to another extremely difficult due to the presence of water. To a relatively primitive species, they would seen impenetrable. If, however, you would like to say that their magic should be advanced enough to cross a body of water, then you could resort to the age old technique of superstition. Anything from an ancient monster to the unknown could be lying on the other side according to them. The Americas, for example, obviously exist, but due to the Atlantic and Pacific ocean, it took the people from the 'mainland' un unimaginible amount of years to build proper boats, cross over and finally reach the other side. And even that required the us to feel the need to reach India. Your species might not want or need to explore further than where they already are. [Answer] If you can cope with having a world in the size of Uranus instead, there would be some interesting topics that can add to your story. 1) The gravity on the surface is interestingly low. It's actually a bit lower than on Earth. It may differ on the poles though since the rotational speed is contributing to the actual surface gravity. 2) There are areas that are relatively calm and some that have a hysterious weather. This of course depends on the atmospheric pressure. If you have a thinner atmosphere then you will have a calmer weather. 3) The rotational speed is very fast and makes an Uranus day shorter than Earth's. It's possible to modify this for a story but if it differ too much the gravity will either be too high (or negative, which will use it's excess energy to sling particles out from the planet at the equator until the gravity returns to zero there). 4) The orbital period of Uranus is 84 years. If the planet "moves" toward the sun it will of course be shorter, but it is also already hotter since it have a large greenhouse effect so it doesn't have to be moved so much. It is also more unlike that a planet of Uranus size will form too close to the sun. 5) The atmospheric pressure is very, very high. You may have a planet with much lesser atmosphere if you want it habitable. In universe, this would be a realistic option if the planet doesn't collect too much gaseous substance from its creation and on. 6) Its surface contains more ice and the atmosphere contains more helium, hydrogen and methane than its Earthlike counterpart. It is because a larger planet that have as big gravity field as Uranus doesn't lose light atoms. Earth loses atoms like hydrogen and helium, therefore as time passes we lose our water into space (as Mars already have done) and so alike is Helium very uncommon here since it doesn't bond to a heavier molecule. The effect of the Uranuslike planet is that it will have more water (Since hydrogen bonds with oxygen), or ice. It will also have a much higher greenhouse effect (with the methane as the biggest contributor) 7) Uranus have many moons and they are relatively large. They can be colonized for a specific purpose or inhabited in a story. 8) The composition of the inside is entirely different from Earth. Even if the outside have a solid cap of ice there may be deep oceans behind the surface thanks to the large amount of water it has collected. The planet will also have much larger tectonic activity (continents that moves) since it doesn't have an all solid interior. The summary is: I see a possibility to make a habitable planet out of a planet at the size of Uranus. There are a lot of interesting topics surrounding this size of planets that doesn't appear to planets in the size of Earth. You may imagine a larger one too, but it may probably not be surrounded with so much interesting topics since because when it is too big (We aren't certain where exactly the limit is) the interior pulls itself so hard that the interior composition changes, the surface comes closer to the core and the surface gravity will be extreme. If you find this parameters thrilling, you may read more about Uranus and make your modifications to make an exciting world from a real stellar example! [Answer] Assume that your planet has few if any metals, in particular no iron core. Then you can have a somewhat larger planet (someone else can do the math to figure out just how much bigger). See for instance Jack Vance's "Big Planet" and other stories set on the same world. [Answer] Interesting topic. Assuming it is a fantasy world so what if the planet would be formed from two different matters. Like dark and visible, or gravity and antigravity. Probably some nonsense, but it's a fantasy :) One trapped inside during formation would create fast rotating core, perhaps some sort of antimatter and antigravity origin; surrounded by heavy gases. The outer part would consist of visible matter pushed by gravity to the centre but bouncing of antigravity core thus hovering in the space would create outer crust rotating by different speed or perhaps even in the opposite direction. The outer crust would rotate slower to allow for day/night time. The planet could have a giant gas ring permanently exchanging gases between planet and the ring dividing the planet in north and south as massive storms are happening at the equator where the ring is touching the ground. The ring majestically reflecting the "sun" rays would create gigantic space mirror most visible during sunrise and sunset. In the equator also you would have a series of fast changing sink holes connecting outer atmosphere with inner atmosphere beneath the crust. That also will be the only ground connection between north and south. Sweet :) [Answer] I'm sure I'm coming into this a bit too late but I'd like to build on the comment made by @2012rcampaign & to a lesser degree the answer provided by @abcde. Essentially, a world the same size or slightly larger than the earth could be made much "larger" from the perspective of a medieval traveler by doing the following 3 things: 1. greatly reducing the amount of surface area covered with large bodies of water 2. more evenly distributing what's left over the surface of the planet 3. dispersing mountain ranges more evenly (and in smaller groups) across the planet Point 1: The overall amount of available water would have to be decreased AND I would recommend flattening out the surface relative to the areas of the planet that might (such as on earth) be covered by ocean... Currently the continents on earth are like very large islands, which we live on the top of, when you consider the depth of the part of our world now covered by oceans. If you flatten this out, so higher land like the continents, would not exist, or would be very rare then this produces much more area that must be traveled. In the absence of enough lower land, less water would likely be needed to provide enough for the sustaining of life because it could be made to be available across the entire world... where now the water generally runs off into the oceans and is lost until it evaporates and returns (sometimes) to the contents as precipitation. So replace the oceans with many relatively shallow lakes spread fairly evenly across the world. The presence of many lakes, rivers, vast marshes, & other water features in place of oceans, might provide enough evaporation for a fairly normal water cycle (water evaporates from the surface so it might be possible to have 45% of the surface covered with water without having large concentrations of water, along with the evaporative effects of much larger areas of vegetation). Point 2: If there were no large oceans & the general level of the surface of the planet where flattened out, there could be vast areas of very difficult terrain including: -Very large marshes/swamps -very tall seeming mountain ranges (the mountains we generally think of are all on top of contents which are nearly mountains themselves from the average depth of the ocean floor... so take away the contents and have a few mountains reach up past where a content would have reached... this would effectively be very tall mountains...) very broad, long, slow moving rivers (with less of an incline toward an ocean both longer, more broad, & slower could be possible... though none of it guaranteed given that there would/could also be many lakes, swamps, etc...). Point 3: Finally you may actually have to more evenly disperse mountains into smaller mountain ranges, which are also spread more evenly across the surface of the planet. Mountains provide runoff of snow and a condensation point for clouds (precipitation often occurs around mountains as, if I remember correctly, clouds are pushed up by the movement of atmosphere being deflected up by the presence of the slope of the mountains...[colder thinner air, as I understand it, can hold less moisture). If the mountains are more evenly dispersed then having many more bodies of water would be more believable as would having an overall greater 'flatness' to the world. Sounds like an interesting story, good luck! [Answer] In 1981 Robert Silverberg's novel "Lord Valentine's Castle" was nominated for a Hugo (Joan Vinge's "The Snow Queen" won), and won the Locus award. It was the first of many stories set on [Majipoor](http://en.wikipedia.org/wiki/Majipoor_series), a world ten times the diameter of Earth, yet having a similar gravity. The explanation given was that the core was far less dense, and that consequently the world was very poor in metals. It's been over thirty years since I read that novel, so I can't recall if there was any more justification for the large size but normal gravity. Nor do I recall if there was any discussion of lack of tectonics and a molten metal core, and the effect on magnetic fields for the planet. I do recall that characters sometimes travelled for years to go from their origin point to a destination. There were also descriptions of cities with populations in the billions. The setting has a fantasy feel to it, but the foundations were science fiction, with multiple races of aliens settling the world over thousands of years, displacing the natives. If this is not enough, many years before these novels, in the mid-1950s, Jack Vance wrote a pair of novels ("Big Planet" and "Showboat World") which take place on a large planet with gravity similar to Earth's, putatively due to low density and a metal poor core. ]
[Question] [ I'm not talking about world-ending, global-scale thermonuclear war, nor about massive salvos of missiles being fired at countries by other countries. I'm talking about, say, a few divisional-level ground-combat armored forces with a contemporary or near-future tech level throwing a bunch of [Davy Crockett](https://en.wikipedia.org/wiki/Davy_Crockett_(nuclear_device))-style weapons at one another without it escalating into a full-scale nuclear war. My question: why would they limit themselves to weapons on this scale, rather than simply escalating into a world-ending conflict? Is such a thing realistic? Keeping this open and unanswered for a while to see as many perspectives as possible. [Answer] The use of small nukes is already common. If many wars and nations have already been using small nuclear weapons without escalation, then our world's fear of escalation is demonstrably unfounded in your world. Perhaps many nations have an agreement limiting the size of weapons that they use, reserving their big exterminators as a deterrent against the big war that never quite comes. Or perhaps the maximum size of nuke in common use has been determined by other means, like an International Criminal Court case, or the fiat of a major nearby power. [Answer] Why doesn't every war escalate to full-scale world war? As long as nations realize that the nukes are merely being used as tactical weapons and not as attacks on them, there is no reason to treat the use of nukes as different from any other weapon. That is, the heavier the weapon used, the more seriously other nations would take the war, and the more warily they would treat the combatants, but they wouldn't jump to battle merely because nukes were used. [Answer] 1. They can't escalate because nukes cant fly. <https://en.wikipedia.org/wiki/Strategic_Defense_Initiative> > > The Strategic Defense Initiative (SDI), nicknamed the "Star Wars > program", was a proposed missile defense system intended to protect > the United States from attack by ballistic strategic nuclear weapons > (intercontinental ballistic missiles and submarine-launched ballistic > missiles). The concept was announced on March 23, 1983 by President > Ronald Reagan,[1] a vocal critic of the doctrine of mutually assured > destruction (MAD), which he described as a "suicide pact". Reagan > called upon American scientists and engineers to develop a system that > would render nuclear weapons obsolete. > > > In this world the SDI system takes out rockets suspected of carrying nuclear weapons. Only small weapons like grenades and artillery shells can slip by the eyes in the sky. 2. Small nukes are what they have. <https://en.wikipedia.org/wiki/Nuclear_weapons_and_Israel> > > Tactical nuclear weapon: Israel may also have 175 mm and 203 mm > self-propelled artillery pieces, capable of firing nuclear shells. > There are three battalions of the 175 mm artillery (36 tubes), > reportedly with 108 nuclear shells and more for the 203mm tubes. If > true, these low yield, tactical nuclear artillery rounds could reach > at least 40 kilometres (25 miles), while by some sources it is > possible that the range was extended to 72 km (45 mi) during the > 1990s. ... > > > > > Nuclear land mine: Israel supposedly has deployed multiple > defensive nuclear land mines in the Golan Heights. > > > A small country fighting in close quarters with its neighbors might not want to nuke everything up. They have got to live there afterwards. Also a small country with a limited amount of nuclear material might see practicality in not putting all of its eggs in one basket. Spreading the nuclear resources among many smaller nuclear devices improved the odds of at least one being useful - as opposed one one huge bomb that is intercepted and that never goes off. [Answer] NATO defence of Europe was based on the use of Tactical nuclear weapons. The Soviet land forces in Europe were larger in number and had more tanks, and there wasn't a good defensive line between the Soviet-occupied "iron curtain" and the "free west". It was believed that a simple mass advance by Soviet forces would overrun Western Europe. It was possible that Western Europe could have maintained sufficient war footing to make this unlikely, but instead they chose to sit behind a tactical nuclear shield. The plan was simple; if the Soviets advanced, NATO would drop nukes on the advancing forces along bottle necks, such as [the Fulda gap](https://en.wikipedia.org/wiki/Fulda_Gap#Strategic_responses_to_the_geographic_feature), using nuclear artillery or other weapons. And if that didn't work, to escalate up to strategic nuclear use. A Tactical response, using a similar sized weapon, would probably occur. Including press releases and diplomatic messaging that this is not an escalation, that the weapon was used Tactically against a military target, and that the yield was similar. If the original nuke used was about a 20 ktonne one (with some uncertainty), the response might be a 15 ktonne one, and the diplomatic and press releases might state that "it was a proportional response under 25 ktonnes". While this would be dangerous, it could easily lead to a series of such weapon use, each time "under 25 ktonnes". Each side might then seek to not escalate beyond that line in the sand, because if they did, the other side would as well. Something similar happened with strategic nuclear brickmanship in the cold war. The Tsar bomba had its yield dialed back to avoid a yield race; it was set off bigger than the biggest American bomb, but a large percent smaller than it could be, simply to avoid further escalation. After the first few bombs, there would be a known convention that use of under 25 ktonne (or whatever) yield tactical nukes is acceptable in warfare if used against military targets. And both sides would be somewhat reluctant to break that rule; both sides might stretch it (firing 4 25 ktonne nukes in one MIRV? Is that 100 ktonnes or not?), and eventually you might get a treaty between two warring nations. It would help if the war was not an existential one; ie, neither side is in danger of ceasing to exist. So a proxy war where the locals had a limited number of small nuclear weapons (like Cuba, or even parts of Europe) and escalated. [Answer] Without an external reason for why missiles don't exist, this is unrealistic > > No tactical nuclear weapon has ever been used in a combat situation. ([Source](https://en.wikipedia.org/wiki/Tactical_nuclear_weapon)) > > > The only reason to not use strategic nuclear weapons is because you want a "surgical" conflict, you want to preserve something. This has a simple name: Weakness Leon Trotsky once made a very practical observation: > > There are no absolute rules of conduct, either in peace or war. > > > A war is fought either to gain something or to stop another from gaining something. The question remains, what is a nation willing to risk to gain that something, or stop another from gaining that something? So far, the world has been willing to *not* risk everything. But our single data point, our own history, suggests that there is a limit. That limit is the step into tactical nuclear weapons. Hollywood sometimes sucks Hollywood is in the business of selling a cheap fix. Quick entertainment. And so they need to present fundamentally broad ideas in very short periods of time. Consequently, Hollywood makes it seem like tactical nukes basically don't exist — that the step into nuclear war is a whole lot shorter than it really is. Maybe Hollywood's right, but it's probably not. With the exception of lunatics,1 the world has proven in all but two cases2 that it will not take that step to strategic nuclear war without a whole lot of something happening first. Oh, we'll posture and cast the proverbial vulgar hand gesture at one another — test a few nukes in out-of-the-way places to prove we have them — but we won't actually pull the trigger. But we've never seen what nations will do if someone pulls a tactical trigger. Tactical nuclear warfare is the trigger for strategic nuclear warfare I can't think of any reason why anyone would roll out strategic nuclear forces during a conventional war. I'm not even sure I'd believe a story that presented it as a last-ditch effort to win an already lost conventional war. That doesn't reflect the subconscious fear the world feels about nuclear weapons. Likewise, I can't think of a reason why any country capable of a strategic nuclear response would hesitate to use it if faced with a tactical nuclear attack. Why? Because the doofus is willing to use nukes at all** And your only option is to stop him dead in his tracks before he lobs even one more shell. Having lived through the cold war, the Cuban missile crisis, and a number of other [doomsday clock](https://thebulletin.org/doomsday-clock/) events, I can tell you that one of the greatest reasons no one would dare use tactical nukes is that the rest of us.. all* of the rest of us... are scared to death of it.* *So, what conditions might* allow tactical but not strategic nuclear warfare? 1. The "target" does not have strategic nuclear capabilities and isn't important enough for those who have strategic nuclear abilities to stand up and fight back in their name. 2. Enough time has passed on your world that everyone who remembers the nuclear testing, use of nuclear weapons, and any cold-war-like conditions that threatened nuclear strikes, and at least one full generation beyond that, are dead. (In real life this might, maybe, happen somewhere between 2080-2100.) No one really remembers just how bad the consequences or even the fear were, leaving the world stupid enough to think that a tactical attack really wouldn't be that bad.3 3. A nation develops what it sincerely believes is tactical nuclear protection for their military, opening the door to the idea of a "safe" tactical nuclear war. Note:** I can't actually imagine a world with artillery but not rocketry — but that's what you'd need to have tactical nuclear capabilities but not strategic capabilities. I consider this incapable of attaining suspension of disbelief, but that's just my opinion. But, I do have one more idea... 4. Zugzwang. It's a [chess term](https://en.wikipedia.org/wiki/Zugzwang) that describes a point in the game when neither player can make a move without significantly degrading their defense. Tactical nukes might be believable if you set up your story with a condition where neither military can make any move without basically giving up the war. Their only option is to use tactical nukes and hope like crazy the other guy won't respond with strategic nukes. This would actually make a fabulous story (I mean it, a Hollywood-options-paying-for-your-grandkids-college kind of fabulous), if you can seriously and believably set up the zugzwang. In this case, it's a race when the two combatants realize the zugzwang is forming, realizing they can't avoid it, and rolling out the tac-nukes first. You can believe the [PEOC](https://en.wikipedia.org/wiki/Presidential_Emergency_Operations_Center) discussion would cause heart attacks all the way over in Tibet. --- 1 By "lunatics" I mean religious fanatics, terrorists, heartbroken nuclear scientists... you know, anybody who has access to a weapon of mass destruction but doesn't have the common sense to not actually use it. 2 Nagasaki & Hiroshima.... 3 If you'll forgive the momentary descent into politics, here in the U.S. we're experiencing a resurgence of Socialism despite decades of world experience with Communism. But we've begun to forget what pure Socialism and Communism can make of a society. You may agree with me or not at your leisure, maybe I'm wrong, but my point is that it's simple to do something stupid once enough people have forgotten how stupid it is. Very few people seriously study history, which is why it's a suspension-of-disbelief-worthy justification for the use of tactical nukes. [Answer] So, a major thing that would allow a power to use tactical nukes but not strategic nukes could be international public opinion, specifically in which tactical nukes are tolerated but strategic nukes would provoke a response. Since there is no historical precedent for this, you could just make your own up. For instance, let’s take a hypothetical war between Country A and Country B (in which they both have tactical nukes, but no strategic nukes). By random chance, some Country A Lieutenant trapped in a hopeless position gets his hands on a Davy Crockett and decides to go for broke, using it on the enemy. Country B gets pissed and reacts in kind, causing Country A to start using them regularly, and so on. The International Community kinda freezes and decides they don’t want any part of that, and let it slide; but issue an ultimatum that if strategic nukes are used, the full weight of the world will fall upon whoever used them. If you’re dealing with a war between full-fledged great powers that would normally be the ones applying pressure onto the nations doing the nuking, you could simply insert the previous, smaller war into the lore before your story takes place. After the war, they redraw up the treaties, which are sorta hazy on tactical nukes but adamant that strategic nukes are not to be used. When your Great Power Conflict breaks out, those great powers will be likely to use tactical nukes for their own advantage, but still avoid strategic nukes since they’d have SOME semblance of a guarantee that their enemy won’t either; and since no one WANTS to start a strategic nuclear war due to M.A.D., they could conceivably stay away from strategic nukes entirely, just so long as their opponent does to. Tl;dr: tactical nukes get normalized but strategic nukes don’t. [Answer] It's not realistic. Nuclear weapons are weapons that have powerful political impacts, sometimes well beyond their destructive power. Your question didn't ask for political impacts, but I'm going to talk about them anyway because they might be more important than the military of sociological impacts. You may use a Davy Crocket-type weapon to wipe out an enemy battalion, but you just created the enemy's best propaganda and recruiting material. The dead battalion becomes a unit of celebrated martyrs and heroes, and you will be portrayed as a sub-human bloodthirsty monster. Historically, most wars end with a negotiated settlement. Nuclear weapons reduce an enemy's willingness to settle (who negotiates with sub-human bloodthirsty monsters?) and encourage retaliatory escalation (it's only fair, after all). Escalation doesn't need to be in the size of weapon. Escalation could mean using more weapons. Escalation could mean using different weapons (chemical, biological). Escalation could mean a wider choice of targets (cultural sites, non-combatants, press). Escalation could mean a change of policy (from a limited goal up the spectrum all the way to genocide). And escalation is easy if they did it first. Once you uncork the genie of escalation, you no longer get to decide the path it takes you upon. The enemy gets a vote. Both populations get a vote. The wider community of peer states get a vote. Your domestic political opponents get a vote. Maybe you go down in history as the conquering hero...or maybe the fool who led their people to oblivion. It will take extraordinary leadership to weather the storm and calm the unleashed forces. Now look at the non-escalation case: By NOT escalating, you deny almost all those parties a chance to overthrow you. Your remaining risk is losing the war (but you can settle before that occurs). Your personal risk is much lower...and you might still win the war anyway. ]
[Question] [ The villainous gremlins are attempting to cause as much damage to the lands of the Empire as possible with as little effort as practical. They have numerous plans to this end. One such plan is to blow up the granaries/silos which store all the recently harvested grain (mostly wheat and barley), depriving the Empire of food and possibly killing people as an added bonus. They don't have explosives, but if conditions are right all they need is a flame. It is well known in the modern era that granaries and silos are an explosion hazard, due to [dust explosions](https://en.wikipedia.org/wiki/Dust_explosion). However, from my investigations, it would appear that such explosions were only of considerable risk after industrialisation. The list of [notable dust explosions](https://en.wikipedia.org/wiki/Dust_explosion#Notable_incidents) starts in the 19th century. The smaller scale of pre-industrial grain and flour handling seems to have [reduced the risk of explosions](https://www.reddit.com/r/AskHistorians/comments/aggymp/how_did_folks_keep_flour_mills_from_exploding_all/). [Food storage](https://www.reddit.com/r/AskHistorians/comments/pwjls/flour_in_the_middle_ages/) was typically in the form of whole grain rather than finely powdered flour, which would further reduce the risk of explosions. In favour of explosions, grain is still combustible (although I don't know how combustible). And our saboteurs can deliberately stir up grain and dust to improve the chances of an explosion. But it is unclear if these factors will be adequate. The climate of the region is comparable to Great Britain or some other parts of Europe (with cold, wet and sometimes snowy winters). The technology is roughly comparable to the late medieval era. Sufficient grain is produced to warrant bulk storage over winter. I'm not entirely sure on what layout a practical granary or silo for this climate might look like. Great Britain preferred to have shacks raised above the ground as [granaries](https://en.wikipedia.org/wiki/Granary). The pictures don't show how the grain is stored, but it seems to be at the same level as you enter, which seems to suggest that it is confined to boxes or sacks or something which might inhibit explosions (but if you have information which says otherwise, do share). Another way of storing grain is in a [silo](https://en.wikipedia.org/wiki/Silo#History), which is essentially a pit in the ground. This is the method implied in the answers to [this question](https://worldbuilding.stackexchange.com/q/85014/55824). Having a large pile of grain sounds like a prime candidate for an explosion. However, a [source](https://dl.sciencesocieties.org/publications/aj/abstracts/12/5/AJ0120050175?access=0&view=pdf) I have found seems to suggest that pre-industrial silos were preferred in dry lands, and some wet lands depending on their soil (such as France) were not suitable for silos. (I don't have full access to that source, so can only read the first page.) If there was need for additional grain storage, would the people of the Empire build silos or granaries, or could they build either? If these structures can explode with different measures of ease, then the relative abundance of these structures would affect how easy it is for the saboteurs to damage the Empire's food supplies. In these circumstances, would it be relatively easy to cause a catastrophic dust explosion in a medieval grain storage building? I am aware that it should be possible to contrive a scenario where such an explosion can occur, but if the scenario is too contrived then the saboteurs would look for an easier method to destroy the Empire's food supplies. On the other hand, if blowing up a granary is as simple as kicking up some dust and chucking in a match then they could use the strategy with abandon. Any examples of pre-industrial grain explosions would be appreciated. Otherwise a solid argument on the plausibility or otherwise of grain explosions in the medieval era will be good. Bonus points for being applicable to my setting's climate. [Answer] Yes they are possible, we have records of them happening. Although grain mills were a much bigger risk, since they could generate both far more dust and a spark. They even occasionally developed safety systems to warn when the conditions were right, mostly when the stones could easily generate a spark. This tells you they must have been common since safety measures tended to be few in antiquity. There were many ways grain was stored, it varied quite a lot from place to place and there was surprising little standardization. In bulk storage shoveling and stirring grain was common and could generate a lot of dust in dry climates. Grain was handled constantly for a multitude of reasons and people were regularly employed to sweep up the dust it generated. [J. V. Van Leuven, 'Prehistoric grain explosions', Antiquity](https://www.cambridge.org/core/journals/antiquity/article/prehistoric-grain-explosions/866692238D2F95CAF4B123E5BF987721) This source indicates the following factors contributed to grain explosions in early history (and indeed today): * Dry climate * Large-scale storage * Lack of ventilation to remove dust * Regular handling of the grain * Long-term storage (on the order of a year), which increases the amount of dust The source does not specify how forceful these explosions were, whether they could be comparable to modern grain explosions. Nor do the specify how much damage was done by the explosion vs the subsequent fire. Note also that the bulk of the source is behind a paywall, like so many papers. Note however grain FIRES were far more common, so if you just want to destroy the grain a fire will work just as well if not better. Fire are possible in a much wider set of circumstances. They could even occur to spontaneous ignition of damp grain. Grain like any dry starch burns very vigorously. Burning grain stores was a known way of attacking an enemy, and was very effective. [James A. Thorne, Warfare and Agriculture:The Economic Impact of Devastation in Classical Greece, Greek, Roman, and Byzantine Studies 42 (2001)](https://grbs.library.duke.edu/article/viewFile/1861/3491) [Answer] A medieval granary is missing the main source of grain dust that could form an explosive mixture: high volume mechanical transport of the grain. Augurs (for lifting grain), belts, and so forth jostle the grains against one another, rubbing off tiny bits of the bran. This is what forms the dust that can then collect in non-circulated air to form an ignitable/explosive mixture. In a medieval granary, the grain is moved by people with scoops (think of a shovel with moderately deep spoon-shaped blade), or by gravity, in far smaller quantities and at far lower rates than in a modern grain elevator. Because of this, the level of dust in the air will tend to be much lower. Where grain dust explosions did occur (as far back as Roman times) is in mills. Here, the grinding of the grain produced dust which, in the relatively enclosed space of the mill itself, could easily collect to ignitable levels. In an age when artificial light meant an open flame, this could and did lead to explosions that killed people and destroyed mills. This was common enough that torches, lamps, and candles were banned from mills for centuries. Because static electricity and friction can still produce ignition, such a ban wasn't a universal solution to the problem, but it made mills safe enough to work in that they at least weren't banned from populated areas the way gunpowder mills were. [Answer] ## The key is pressure > > If rapid combustion occurs in a confined space, enormous overpressure > can build up, causing major structural damage and flying debris. The > sudden release of energy from a "detonation" can produce a shockwave, > either in open air or in a confined space. If the spread of flame is > at subsonic speed, the phenomenon is sometimes called a > "deflagration", although looser usage calls both phenomena > "explosions". > > > <https://en.wikipedia.org/wiki/Dust_explosion> > > > While grain dust is certainly the hazard in modern silos that normally starts the combustion, it is more likely the silo and not the grain that has meaningfully changed. The issue with industrial era granaries is that they are much more airtight systems (typically made out of welded plate steel or sealed concrete) than these older buildings were which means that pressure caused by things burning on the inside can build up much faster than the system is designed to vent gases. This pressure is the difference between grain that burns and grain that explodes. In contrast, older silos were generally much smaller and made out wood. This meant that you had more gaps for air to flow out through, and that the size of the chute to the volume of the container was much larger. So when things went up in flames, you'd have much more of a burn instead of a blast. ## How to get a boom This is a two step sabotage. First you need to make the grainery airtight. If the gremlins sneak into it when it is first done being built, they could paint the walls with a thick layer of pine resin or hide glue to make sure airflow can't get in and out through the walls. Then when the silo is done being filled, you throw in a few buckets of water, and glue the door shut. When you add water to the grain, it will begin growing yeast. The yeast will then start turning the starches in the grain into alcohol which as James Cook pointed will eventually combust due to exothermic decomposition. With the grainery now being a closed system, you will get the exact same sort of issue you see when you don't properly vent the stills where people make alcohol on purpose: you get an explosion. [Answer] As noted, medieval granaries did not explode, because of the lack of large quantities of fine powder found in modern grain mills and silos. As also noted, spontaneous combustion does occur in all sorts of materials, including hay, sawdust and anything else flammable with a large enough surface area. However, people are usually aware of this and take precautions (such as farmers checking internal temperature of haystacks). If you have coal mines these might be a better bet. It was once thought that explosions were caused only by gas, it turns out many were caused simply by coal dust. One test with a few hundred kilos of powdered coal blew out windows several miles away. Fuel-air explosions with liquid fuel can be equally dramatic. If your culture uses oil, with a bit of heat and confinement and mixing with air your gremlins might create a satisfactory boom. [Answer] Add water. Wet grain decomposes generating heat. The heat in turn increases the speed of decomposition. Grain and for that matter hay, always needs to be stored dry. Many farmers have lost barns due to wet hay causing fires. I knew several farmers that had this happen to them. I also grew up next to a family owned feed mill that ground grain to make animal feed. The owner went on vacation leaving his adult sons to run it for a couple of weeks. They go a load of wet grain. Instead of throwing it out they decided to wait until their dad returned from vacation. Instead the grain exploded in to flames and the mill was burned down. ]
[Question] [ The Romans had [pumps](https://100falcons.wordpress.com/2008/01/24/a-roman-pump-in-perfect-condition/), [aqueducts](https://www.google.com/search?q=roman%20aqueducts&rlz=1C1NHXL_enGB711GB711&oq=roman%20aqueducts&aqs=chrome..69i57j0l5.7301j0j8&sourceid=chrome&ie=UTF-8), [water wheels](https://waterandenergypart1.weebly.com/how-ancient-cultures-used-water-power.html) (which were used to grind flour, saw wood & stone etc), [valves](http://www.valvemagazine.com/web-only/categories/manufacturing/4947-ancient-roman-valves.html) & [pipes](https://www.google.com/search?q=roman%20pipes&rlz=1C1NHXL_enGB711GB711&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiDyIST7JbgAhU9SBUIHa8mBYoQ_AUIDigB&biw=1280&bih=616) (they are known to have used stone, clay, [lead](https://www.google.com/imgres?imgurl=https%3A%2F%2Fthumbs.dreamstime.com%2Fz%2Flead-pipe-ancient-roman-belgrade-serbia-49500418.jpg&imgrefurl=https%3A%2F%2Fwww.dreamstime.com%2Fstock-photo-lead-pipe-ancient-roman-belgrade-serbia-image49500418&docid=4zPuJOF6ftmTtM&tbnid=u-CEMlPiRDIpAM%3A&vet=10ahUKEwiCjb2V7JbgAhV6SxUIHWOqBa4QMwhiKA8wDw..i&w=1300&h=953&bih=616&biw=1280&q=roman%20pipes&ved=0ahUKEwiCjb2V7JbgAhV6SxUIHWOqBa4QMwhiKA8wDw&iact=mrc&uact=8) & copper for pipes). All the ingredients in fact for a [pneumatic tube](https://en.wikipedia.org/wiki/Pneumatic_tube) system for delivery of small packages. So, would an alternate past where the Romans had actually put all these things together to produce a pneumatic tube postal service for the city of Rome be plausible? The air pumps would be powered by water wheels. Only for government buildings and districts occupied by wealthy citizens of course. > > [How the Romans made lead pipes](https://www.youtube.com/watch?v=cRNQVwUr_hk) > > > Copper pipes (if used) can be made the same way (hammered around an iron or steel mandrel) so any issue of standardization is more or less inherently solved by the production method. > > > Message-tubes to feed into the pipes can also be made this way hammered around a slightly narrower mandrel with leather or felt (rather than rubber) washers to give a relatively airtight fit in the pipes. > > > [Answer] Reality check, sadly, I'd have to say is: ## IMPLAUSIBLE The only thing truly implausible about the scenario is slaves. Rome had a lot of them. It becomes a simple matter of economics: it's much cheaper to build an aqueduct than it is to supply Rome with water via lines of slaves forming a bucket chain all the way up into the mountains; whereas it's much cheaper to tell a slave to "pop on over to M Lucius Cicero's office with this packet of letters" than it is to build a pneumatic tube system on a large scale. Is it technologically possible? Absolutely! Does it satisfy the cool factor? Sure! But is it plausible in a heavily slave dependent Roman Empire? That I'd have to say is no. [Answer] I'm voting for Yes Lead pipes can be hermetically sealed. It's lead. It could be hermetically sealed with a candle (well... not a candle... but if they can extrude lead pipe they can obviously melt it). It's possible that [the Romans had springs](http://jaysromanhistory.com/romeweb/engineer/art16.htm). This is good! Because the manufacturing tolerances of the pipe probably wouldn't allow even a loose-fitting canister. BUT! Throw some spring-loaded legs with wheels on the thing such that a smaller canister can roll along with shock absorption... now we're cooking with gas! But, those springs have consequences. No vacuum. But... that could easily be fixed with a leather collar to seal around the canister. More complex than I like... but it's solving problems. I'm not super fond of pneumatics for this purpose. I don't believe sealing the pipe is the problem. I do believe creating the vacuum in the first place could be. Pumps are good for moving fluids, but you need really, really, really well sealed pumps to create even a mediocre vacuum. Water, on the other hand.... Fill the pipe with water from the sending end. When the canister arrives, the recipient closes a ball valve, allowing the water to drain on both sides. How does the sender know when to let the water drain? When the pressure equalizes. Now, officially, measuring pressure wasn't something that happend until the 1500s. But it wouldn't be hard to have a small pipe affixed to the main line, probably pointing up, such that when the line pressurized a spray of water came out of it ringing a bell. That would tell the sender to turn off the water and let it drain. The line would need to be designed such that the canister didn't fall back as the water drained. Hey... you might not even need the valves I mentioned. All you need is the ability to turn water on from both sides of the pipe. So, yes, I believe it's plausible for an alternate-history story. [Answer] If you want to use pneumatic post, you need to be able to rely on vacuum. This implies that whoever manufactures the system has to ensure tight tolerances on both the pipes and the vessel, to prevent leakages disrupting the vacuum system. I am not sure manufacturing processes in the Roman Empire could deliver a combination of narrow tolerances and large production, of the order of hundreds of meters of piping on a single building. Moreover, lead is a poor material for this application: being really a soft metal, I doubt it would withstand the pressure differential between the vacuum on the inside and the atmosphere on the outside. You would either get breakages/deformations, or would need to use thicker walls, making again tolerances more broad. [Answer] [![Pneumatic tube diagram](https://i.stack.imgur.com/f2tQS.jpg)](https://i.stack.imgur.com/f2tQS.jpg) It is entirely possible to have a series of pneumatic tubes working in ancient Rome. The technology did not come into play until the early 1800's, but there is nothing that could have stopped it from happening at an earlier time. Romans had lead pipes. They had waterways to transport water to homes. By adding leather and grease gaskets to connect the pipes, you can send objects down the pipe. You could use the existing aqueducts to run the pipes. The issue is having a standard circumference, say 6", a cylinder with leather gaskets on each end and a source of air pressure. This isn't much different than the version first operating in London in 1850. The air pressure on modern systems is only 15 psi. You could use a windmill, a water wheel to provide blower power. A blower is a simple squirrel cage fan turning fast enough to push air. Your bathroom fan is powerful enough to do the job. Good luck with your series of tubes. * <https://en.wikipedia.org/wiki/Pneumatic_tube> * <https://www.blowervacuumbestpractices.com/system-assessments/conveying/importance-particle-velocity-dilute-phase-pneumatic-conveying> [Answer] > > So, would an alternate past where the Romans had actually put all > these things together to produce a pneumatic tube postal service for > the city of Rome be plausible? > > > * Technically : Maybe * Practically : No As others pointed out, it would definitely have been technically possible if they wanted to build such a thing. There have been many amazing machines and structures built in the past which perplex us even to this day. The fact this wasn't planned or build was probably beacuse, letters, especially written by and to wealthy people would probably be handled only by their trusted companions. There was no digital signature, thus, people took great care as to who had access to their letters and seals. So if they built such a system, they would have to deploy massive guards to secure it. Thus, it was much better to let letters be delivered by the hand of your trusted compatriots. [Answer] # Technically quite possible, Practically not at all. It would fail for the same reason that such systems failed to gain popularity in to open public for us. Verifying delivery: Intrinsicaly, the pneumatic tube system is one-way. You load the tube, launch it, and ..... That's it. It does not include any means of verifying that the delivery succeeded. It does not include any means of verifying that the correct person received the delivery. It (usually) does not even include any means of verifying that the exit point of the tube is open, available and unblocked. All of these shortcomings can be worked around using fancy mechanisms, but that requires fancy mechanisms. Which impose their own cost, failure points, and complexity to the system. Damage of delicates: The delivery system is inherently violent, with lots of sharp accelerations and stops. And people will inevitably try to ship stuff that is not strong enough for the system. (anecdote: Back in the '70s ,at a local store that used a pneumatic tube system to deliver invoices, money, and office stationery to and from the cashiers: Cashier sends a message "my pen is dying, send a replacement please". Instead of a ballpoint pen, the warehouse sends through a fountain pen. Which shatters upon arrival, splashing cashier and several customers including myself with black ink.) Breakdowns: An air leak, or a misaligned cartridge seal, or something sticky either on the cartridge or in the pipes, brings the whole system to a screeching halt. Then someone has to get the rod, and start reaming the system to remove the blockage, then again with a rag to clean it, then again with another rag to either oil or powder the tube, depending on the system. BIG downtime. People are idiots: The pneumatic tube system is very much open to abuse, and inevitably some braindead person will play with it. "What happens if I put a can of Cola in this thing, the size seems about right", they wonder. Or, "Hey Pete, you want a HotDog? Exxxxxxpress delivery coming right up!". These abuses inevitably lead to the scenario above, where the Man with the Rod needs to be called out. Pneumatic tube delivery systems work fine, in a professional environment with trained, disciplined users. For frequent delivery over relatively short distances between a very small number of recipients. Over long distances, or where the number of recipients become many, or the operators are mere Humans.... They are not at all optimal. ]
[Question] [ I had the idea for a group of advanced humans using technology to rework their bodies so that they lay eggs instead of giving birth to live young, just like a platypus (possibly to survive in an alien environment). What kind of advantages would laying eggs provide? [Answer] I could see this being a "great idea" some scientist has as a solution to the "problem" of pregnancy for those colonizing planets. The reasoning would be that the women would lay the egg, pop it into an incubator, and then get back to the important work of helping build a new colony. Plus, they wouldn't have to worry about the menstrual cycle anymore! (Or would they? Which sounds worse to you - a period or having to lay an egg every 28 days?) You could have it be something only one group of colonists try because "why would we ever doubt the charismatic man in a lab coat? I mean, he's a scientist! He's got to know what he's talking about, right?" So the women let him tamper with their bodies in the name of "science!!!" And then they come to learn that having to lay an egg instead of wearing a pad isn't all it's cracked up to be. Ooooh, bad choice of words. [Answer] There are very few situations I know of where it would be useful to lay eggs. Why do I say that? Well, evolutionary speaking, we see transitions from egg laying to not-egg laying, but only a handful of cases where it might have gone the other way, if any. Fundamentally, laying an egg requires one to provide the resources one needs for a fetus to come to term. It requires the maximum expenditure of resources, because you can't add proteins or calories to an egg after it is laid. You have to give it everything it could possibly need. On the other hand, with live birth, you only have to give it what it actually needed. The one thing I could think of that might sway this behavior is if one lived on a planet which was immensely hostile such that you need every able body working in order to survive, but you could create some "safe havens" where one could nest. In that extremely unusual environment, it might be convenient to be able to lay the eggs and then continue working. While plenty of women do indeed keep working while pregnant, and there are stories of slave women giving birth in the fields and continuing to pick cotton, it's clear that is a less than ideal solution. Freeing one-self from the fetus quickly would be beneficial in those cases. [Answer] None - but there are a lot of disadvantages... * Carrying the fertilized egg until gestation is intrinsically self-protecting and allows the carrier to act without being substantially tied down.1 * Any duck can tell you that keeping track of the brood is a pain in the neck.2 * You need to keep eggs warm, but living in areas with hot sand is a non-starter for me, and feathers aren't her style.3 * Watching anyone turn your children into breakfast would start entire wars.4 --- 1 My wife suggests that I know a lot less about what I'm talking about than I pretend to know, but she concedes that not having to sit on a nest 80% of the time is useful when she wants dinner and a movie. 2 Yeah, she thinks this question is silly. We don't have twins, but we know people with twins and people with kids born but 9 months or so apart, and their lives reek. They reek like spoiling pomegranates. Kinda sweet, but in the end, you have to throw it away. (Don't get me wrong, none of them would trade their kids for the world, but when cornered about the issue, none would disagree that broods are committed-time-multipliers.) 3 She won't wear feathers and while we're getting older and warmer climates are becoming more interesting, when we think back on our 20s, that wasn't happening. Nope.... high altitude and cold weather for us, thanks. 4 She agrees with this, but thinks I'm starting to stretch for examples of why this is a bad idea and is politely suggesting that I'd be less of an idiot if I quit while anyone might think I was ahead. [Answer] In Edgar Rice Burroughs's book A Princess Of Mars, the martian people did lay eggs. They put the eggs in an incubator and under the influence of sunlight they grew for 5 years before the children hatched out. They must have been getting CO2 and water and nutrients, and photosynthesis let them grow. So they started out a nice reasonable small size when laid. Burroughs strongly implied that the women had human breasts, and it looks pretty clear that the babies didn't get milk from them. The reason for these is left as an exercise for the reader. It looks like a good thing if you can do it. Be pregnant for say 4 months. Lay a small egg. Let the incubator do all the work for the next 5 years until your child reaches an interesting age. But it needs the photosynthetic eggs, and it needs the incubators. In his story the unhatched babies were telepathic and they learned a whole lot about society before hatching so they didn't need to get taught a lot of the things we teach small children. I have no idea how to do that, but I'm sure society would be wildly different if small children got to listen in on all the adult's thoughts for 5 years before they ever got involved, and parents never got any chance to lie to them. Right offhand I expect they'd hatch out extremely cynical compared to us. [Answer] You're not likely to see any benefits, at least none that outweigh the problems involved. Size A mundane problem, but a serious one. Humans already have notable difficulty giving birth, and large babies cause particular trouble; some mothers die in childbirth even with modern technology and medicine, and in pre-industrial times that rate was significant. An egg that must ultimately contain such a baby is guaranteed to be even larger (unless you want smaller and less-developed babies, thus effectively premature babies, which poses a host of issues like much higher rates of infant mortality and mental problems) due to the need for the enclosing eggshell if nothing else, never mind any nutrients or other materials that might be left over. That makes all those potential complications more likely and more severe. I don't want to see the consequences of trying to give birth to a baby that is unable to fit through the birth canal; that would be a common cause of death for egg-laying humans without other drastic changes. Widening the birth canal may seem to be an obvious answer, but the design of human hips is a compromise between walking upright and giving birth; a wider birth canal, especially to the required degree (probably at least 50%, because the egg has to hold a human baby and have a shell thick enough to offer actual protection), could seriously impair a woman's ability to walk on two legs. Protection Animals that lay eggs and abandon them do get to scatter many potential offspring, but most of those eggs will be smashed. This is a viable strategy (see [R-selection versus K-selection](https://en.wikipedia.org/wiki/R/K_selection_theory)), but that is not conducive to anything resembling civilization. Animals that guard their eggs, on the other hand, have one parent basically glued to the nest from laying to hatching (which would be months for humans); the care this requires does reflect the possibility of intelligence and civilization as we recognize them, but that puts a heavy burden on whoever is not tending the nest. Pregnancy and live birth, by contrast, make protection relatively trivial. It can be seen as carrying the egg or eggs within the mother's body instead of leaving them outside it, which reduces the problem of protecting the offspring into simply having the mother protect herself, something she would be doing anyways and thus is not an added cost. It also saves the expenditure in energy and materials of creating the eggshell, another point in its favor. Hatching How, exactly, is a human baby going to crack open an eggshell from the inside? We are born rather weak and frail, without any convenient sharp claws or the like. Our skulls are still very fragile, so breaking out with any hypothetical added appendage to the head (a special tooth or horn that falls away after hatching, most likely, but I'm open to suggestions) is going to involve a lot of battering against the shell from the inside, likely causing permanent brain damage. Keep in mind that larger eggs are naturally going to be thicker (read: harder for the baby to break open), to offer more protection: too thin, and the weight inside would crack it just from falling the few inches between the mother's body and the ground. Besides, on hatching, they're still going to be helpless for a very long time. Many egg-layers have offspring that is at least mobile within a few days; if you want your humans to match that, their offspring will have to undergo significantly more development before hatching than normal humans do before being born, which requires a larger egg to hold the larger baby, which in turn feeds right back into the size problem! Also, there are studies that suggest our level of intelligence requires a long period of effective helplessness while our brains develop and learn, whereas species that are born with more development are also more limited in learning capacity; I can't prove this point, and you could probably get away with ignoring it, but it's still something to consider. Conclusion Egg-laying works for some species, but bipedal intelligent humanoids would most certainly not be among them, at least not in anything nature might produce. You say that genetic engineering is involved here, removing the question of evolution, but you'd still need a reason why they would do such engineering to change humans to what (for humans) gives every sign of being an inferior mode of reproduction. [Answer] Advantage? None, I would say. Each egg needs to be large enough to hold a full-grown baby, just before it emerges. Which means a female will have to grow a baby sized egg inside her body, then push it out without breaking the egg. But human females have eggs 'ready' about 12/13 times a year, for about 40 years. There isn't much to gain to have females produce hundreds of huge eggs in a lifetime of which only a handful will be fertilized. What will you do with the unfertilized eggs? Make omelettes? [Answer] The biggest problem might lie in the actual process. As I understand it, egg-bearing creatures need a lot more DNA information than live-action childbearing ones. Since the egg is in a semi-controlled environment (some egg that lies somewhere) instead of a fully controlled one (mother), the egg creature needs a lot of extra plans for temperature changes and other external changes. Making a baby in the mother only requires a recipe, the environment takes care of all the rest. Would probably make more sense to just incubate the babies and grow them in a tank than to try to change up humans to lay eggs [Answer] There are a some benefits that humans could gain from egg laying. They could populate new areas by leaving their eggs there. They could also mix cultures, simply by leaving their eggs behind while traveling. Their culture may also benefit from the rich experiences gained through a brutal childhood. However, these humans would need a few additional enhancements: Their eggs need to be able to hatch unattended. If human's eggs were similar to insect or fish eggs, they could leave their eggs to hatch unattended. This would free the adults from many (or all) of the burdens of child raising. This would also allow for many new and interesting options for territory and culture expansion. Their young need to be able to fend for themselves. For the young humans to have a chance in their new environment, they would need be able to function both physically and mentally after birth. Having stronger survival instincts (like snakes or turtles) would be very helpful. Their young could benefit from multiple life stages. Perhaps the new babies hatch into a worm form, and live in the soil for many years before transforming into their human form (like many insects.) They could also spend many years in a plant form, rooted to the ground while absorbing sunlight and nutrients. Either way, they would benefit from having an intermediate form which allowed them to grow and mature. Their society would need a culture that dealt with unattended children. Their culture would need to be able to deal with the herds of unsophisticated children running around. Perhaps they would accept this brutal stage of life as an important right of passage. Perhaps they would regard their offspring as a lower form of life until they evolve or morph onto mature humans. Either way, egg laying humans would regard human rights drastically different that we do. Keep in mind, may egg laying creatures eat their own offspring! Other creatures care for young that they did not produce. Either way, these human's laws and traditions would need to have some regard for eggs and young. They could be telepathic or have a hive-mind. Many of the complications of egg laying could be resolved through some form of telepathy or linked mind. If the humans shared a hive mind, then newly hatched people would emerge as an integral part of that society. Even if they were only telepathic, the newly hatched people would benefit from the experence and company of the older ones. [Answer] Technological dependence Modern humans are optimised to grow a baby to the maximum possible size that a mother can survive expelling. (Citation: Childbearing mortality rates for parents without modern medicine.) As mentioned elsewhere, an egg requires on-board resources to last until hatching. This increases the size further, and can only extend development time. Why do this, then? Birth is unpleasant [citation needed], so reducing the size of the infant is useful. This means a premature birth in current biology, which is ill-equipped to survive outside. But since you're changing everything, let's let technology take over the developmental support process. A soft-shelled egg is therefore a convenient package to move the underdeveloped (small) baby from in-utero to in-mechano (word?), where it can develop as far as you like. This is not actually too implausible, if you reinforce and then detach the amniotic sac, and have an oxygen buffer on-board. Of course, this means that such modified-humans can no longer breed without technological aid. This looks like plot-fuel to me. ... though at which point, why have an in-utero phase at all? Brave New World had some suggestions there. [Answer] If laying eggs is easy work and not too painful, then I'd say this is definitely beneficial. Being pregnant is hard work. Morning sickness is like having food poisoning every single morning for 3 months, and some ladies stay sick all the way until birth. Not to mention painful stomach cramps, etc.. That kind of stuff can make it very difficult for a woman to maintain her job during pregnancy, too. Other than the effort to produce eggs. One downside I can think of is the emotional impact. Pregnancy also has a slew of hormonal changes associated with it, which tend to emotionally bond the mother to the child prior to birth. More experimentation is needed, but I could definitely see some advantages in terms of comfort and productivity. [Answer] It would provide a lot of good things. There is a possibility of multiple births. An unfertilized egg can provide food. Drawbacks are getting egg bound that's a lot of pain and I'm not sure but I think one might be able to die from it.. Another benefit though is that these babies that were born in possibly protected shells may live longer.. They may be more physically fit.. All animals from the animal kingdom that lay eggs are not at all lazy.. If this is possible, it should be done with free will.. No one is forced.. And we have to ensure the children born are safe from testing etc. I love the idea ]
[Question] [ Could a species, over centuries of evolution, evolve a special organ that stores pure energy and allows it to control its own magnetic field? What possible steps would have to happen for this to occur? Also, do you think its skin would be would be as hard as lead to contain it? I'd like to thank everyone who answered my silly question nearly all the information you shared has been very helpful. [Answer] # Storing Energy Surprisingly, most creatures already do this! Fats built up on the body contain [Chemical potential energy](https://en.wikipedia.org/wiki/Chemical_potential), as does glucose molecules in cells. This definitely isn't storing lightning in your veins, but organic flesh isn't very good with electricity as we know it. Fat itself contains around 9 calories per gram, which is about 37kJ of raw energy waiting to happen. 1 kilo of fat contains 37,656 kilojoules of energy. This is actually rather impressive, compared to our modern batteries, which usually contain around 360 - 900 kj/kg, human fat is a lot better at storing energy than a literal battery in your chest. [Comparison of Energy Densities](https://en.wikipedia.org/wiki/Energy_density#Common_energy_densities) # Storing "Pure" Energy Energy isn't something that can really be pure, but it does have a lot of forms, the one you're probably thinking of when you say "Pure" energy is probably [Electrical Energy](https://en.wikipedia.org/wiki/Electrical_energy). There are two ways to go about doing this in a "Safe" way. The first, is to store [Electrical Potential Energy](https://en.wikipedia.org/wiki/Electric_potential_energy) rather than the energy itself. This means storing the means to generate electricity, rather then the pure electricity, like a traditional battery. If you want examples of how a creature can evolve this, look no further than the [Electric Eel](https://en.wikipedia.org/wiki/Electric_eel). It contains pairs of organs referred to as [Electric Organs](https://en.wikipedia.org/wiki/Electric_organ_(biology)), which essentially uses ATP, which is cell energy, to generate electricity, much like a muscle does. In the eel, this produces either low or high voltage zaps, in this theoretical creature, it may be able to create a magnetic field. This is probably the best method, as it's the safest, and uses the body's already supple energy to charge. The second is to actually store electricity itself in a highly conductive organ, preferably a 100% efficient conductor, surrounded tightly by insulation. Both of these factors are highly important, and are likely reasons that an organ like this wouldn't evolve. If the conductor isn't conductive enough, power will drain from the system slowly, and the organ will unnaturally heat up. If the insulator isn't effective, the power could leak, and potentially stop the creature's heart. This doesn't even go into the idea of how one would charge the battery. # Magnetic Field Control Now, Magnetic Fields can't really be stopped, there's nothing really practical that can be done to reduce the passive magnetic field that organisms put out, but it's theoretically possible for a creature to create their own stronger magnetic field. Electricity flowing through a wire (or a particularly conductive organ) will generate a magnetic field no matter what, which is why [Magnetroception](https://en.wikipedia.org/wiki/Magnetoreception) can be used to detective movement of living things, But if you want a particularly strong magnetic field, you'd need to move a lot of electricity through a small space, usually a coil; This is the concept of an [Electromagnet](https://en.wikipedia.org/wiki/Electromagnet). If the creature can produce a sort of organic wire, probably from a mineral like iron, it would be possible to coil it up somewhere, and send power from the previously mentioned energy storage methods through it. This comes with many of the similar risks as the lightning box did, that is, energy leaks could stop the heart, or the tissue not being conductive enough wasting energy, but it is theoretically evolutionarily possible. ## Evolution of a Magnet Organ. For a creature to evolve something, [it needs to be useful](https://www.youtube.com/watch?v=sAGEOKAG0zw) early in it's development; evolution isn't particular fast, and it does not favor the useless. But if the world this creature lives on is incredibly rich in a [ferromagnetic](https://en.wikipedia.org/wiki/Ferromagnetism) mineral, so much so that most creatures are digesting it, it could be favourable for a creature to generate their own weak magnetic current, to pull food towards them, and that in the like, although this is a bit of a stretch. It seems the most probable way for a creature to evolve this organ, is for it to first evolve the organ required for electrical production, probably to shock prey much like our eel friend, and then from there adapt it to magnetisation, for some unknown gain. Citations provided where possible, much of this is speculation ]
[Question] [ I have some typical gryphons in my world. Bird head and wings, cat bottom half. Four legs and two wings. How crucial is a bird tail for flight? Could my gryphons be good flyers with just having a cat tail instead, or are the two bird wings good enough? No magic should be involved. [Answer] If your world is more or less like ours, and there is no magic, then your typical gryphons will never be able to fly. By typical I'm assuming you mean the size of big cats. There's a reason why large birds don't fly, or can only fly a bit by launching from high perches, or fly very clumsily, or rely mainly on soaring on thermal currents. It has to do with the strength of muscles v. the weight of those muscles and the bones that support them. Even forgetting those inconvenient facts, I foresee stability problems, as a typical cat-like animal would have a relatively big and heavy head on one end and bulky, heavy hindquarters on the other, which would make it very difficult for it not to lose balance if there's only one pair of wings in the midsection. I would advise that you gave the physical realism of the setting a big handwave and just go with the typical gryphons as you imagined them, unless you want them to do something specific with their bird tails. Gryphons belong in the fantasy genre anyway, so their presence should signal the reader that they shouldn't expect scientific accuracy. [Answer] Firstly, flight does not actually require a tail. Many of the pterosaurs lacked tails, or only had very rudimentary ones. Further, some arboreal animals use their tails as in-flight rudders and counter-balancers. For one famous example, consider squirrels. So you could use the feline tail on your gryphon to act either as a counter-balance (shifting weight) or aerodynamically (perhaps it is flattened). And there is no reason why your gryphon could not use both methods. [Answer] Tails are one solution to the stability problem; other solutions exist in nature. Bats have more mobility in their wings due to the wings being stretched between their "fingers" instead of attached to their arms, giving them their characteristic erratic flight pattern which is actually more agile than birds. Insects often have an extra pair of wings, or in the case of flies, specialized stabilizing organs where their back wings used to be. Bees beat their wings in a figure-eight pattern that effectively lets them "flap" twice for every wingbeat, once in the front and once in the back, letting them fly effectively and even hover despite their small wingspan-to-body-size ratio. Gryphons are typically depicted with bird wings, so my guess is that they wouldn't be quite as agile in the air as birds without a feathered tail, but on the other hand they probably don't need to be. My guess is that a realistic gryphon would stalk its prey like any large cat, then pounce and use its wings to gain extra speed and mobility during said pounce. A large (lion-sized) gryphon wouldn't be able to achieve true flight anyway due to the square-cube law. A small gryphon, the size of a housecat, might be able to fly. If you give it bat-like wings instead of bird-like ones it may be more agile in the air and won't need a tail for steering. Also worth noting that the cat's tail is already pretty good at mid-air stabilizing; that's what it's for. It uses its long length to counterbalance the cat's motion in the air instead of aerodynamic properties, but it could be used to steer during a jump. [Answer] Taking from the fantasy world, Pegasus doesn't have a bird tail. Taking from reality, bats don't have bird tails and fly superbly. A whole lot of flying insects also do not have stabilizing tails. [Answer] Most flying vertebrates had ancestors with a long tail. Early pterosaurs (like [Rhamphorhynchus](https://en.wikipedia.org/wiki/Rhamphorhynchus)), early birds and early bats all started out with a long bony tail. So the 'proto-flyer' in each group could have had something just like your cat's tail. Their descendants then stiffened the tail. Then their descendants shortened the tail. The reason for the shortening of the tail in all these groups is that they are sacrificing stability in the air for mobility. Long tails enable very stable flight. Short flexible tails let you be manoeuvrable. Thus any creature with a lifestyle which means it needs to chase prey in the air, dodge predators in the air, zigzag around tree trunks when flying in a forest, or such things will end up with a short tail. Also, you can use the short tail as an aerofoil to generate lift. I suspect (don't know for sure) that is more tricky with a long tail, where the drag it generates may outweigh the lift. ]
[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/22709/edit). Closed 8 years ago. [Improve this question](/posts/22709/edit) I have made a fairly simple time machine. It works by ... well that's not important. It can send one user back in time (up to two hundred years). This person can appear anywhere they want on this planet, carrying what ever they physically can, but can only stay there for two minutes before getting shot forward in time (to the present day, once again any place they choose). (They cannot cease to exist through this action, because ... well that's not important either, just trust me...) My question is thus: What is the smallest change one could make within the past two hundred years to save the most lives? Remember it has to be accomplished within two minutes. Also you are unable to leave anything behind, only the changes you have made, and the memory of you (where applicable) will stay behind. Please hurry, I have much to do and so little time... EDIT Addendum: It was only a matter of time before it would happen. There were plenty of signs we missed. We were foolish. Luckily, their coming coincided with the day I completed my machine. A work fifteen years in progress... We held off stage two testing it until we had a plan. Finally, after months of horror, squad 7 captured one of them. Over a hundred men died that day... The captive was rushed to our last refuge... An old mine well hidden so that we could stand a chance... Twenty of the worlds brightest [admittedly, not such a great feat anymore] waited here. Waiting for this very day. One had never been captured before... But alas, it was a trap. Fire rained from the roof as our last hope crumbled. Without exception, their presence indicates death. Our weapons are more useless against them than...than... oh bother... My machine will allow me one chance (this time) to travel back to make a change. On the topics of weapons I know next to nothing. I have 120 seconds so I must do an action as I do not have enough time to convince anyone of the impending doom. My only hope, the morbid thought that keeps me going is that if I can save enough lives we can last for longer this time. Time we need to formulate a plan. We have concluded that lives == time. Therefore Stage one of my plot is to save as many lives as I can. The more people we have when they come, the longer it will take for them to get to us. Whether in this revision or the next we will come up with a plan. We just need time; and for that we need people... [Answer] Everybody's talking about preventing wars, so let me mention something else, medicine. You could take all of current medicinal knowledge and carry that to 200 years back. This could potentially save millions of life. Major epidemics such as cholera, typhoid, flus would be terminated before they started. We are talking about 200 years back, so that is 1815. That was when the cholera outbreak started. Other major epidemics of past 200 years- * [Cholera](https://en.wikipedia.org/wiki/Cholera#History) * [Plague](https://en.wikipedia.org/wiki/Third_plague_pandemic) * [Flu](https://en.wikipedia.org/wiki/Influenza#History) (This alone could save 50-100 million lives) * [AIDS](https://en.wikipedia.org/wiki/HIV/AIDS_pandemic) (You can't eliminate it but possibly reduce the severity) And more recently- * Swine flu * Ebola Now, the two minute rule is hard to abide by. Maybe you could take a big book of current medicine and place it somewhere where it will receive attention. Maybe at the house of some medicine researcher. Or a science fiction writer where it will generate more interest. It will probably be ignored at first, But if it is well written and actual events start matching, it will generate interest. Of course, this is all speculation, and the events aren't certain, but that's always the case of time-traveling. [Answer] ## Assassinations are fastest Since we only have a two minute window to work with, convincing someone to change their course may prove incredibly difficult. Besides, the kind of changes we would want to make in the target are very difficult to make in just two minutes. (Probably easier in highly religious people because you can show up as an angel and make a command.) ## Karl Marx Marx' writings have had a huge influence on world events leading to the creation of at least two different brands of communism and effected the lives (and deaths) of over a billion people. Because of Marx' writing, Vladimir Lenin took down the Tsar. Mao took over China. Stalin gained control of the USSR, lots of people died. Preventing Stalin alone will save tens of millions of people. Others may write the same kind of things that Marx did but it we have no way of knowing who or when. [Answer] Prevent the assassination of [Archiduke Franz Ferdinand](https://en.wikipedia.org/wiki/Archduke_Franz_Ferdinand_of_Austria), it may prevent WWI and by extension WWII and Hilter rise to power (and also change a lot of other historic events, but I'm don't know enough about history to say which ones). Your Time Traveler just have to go to Gavrilo Princip's home on the morning of the assassination and either kill him, put him to sleep for the rest of the day, or steal his gun. [Answer] If you were to go back and convince China to avoid choosing the One-Child-Policy, it would save 400 million lives, by their numbers! (Probably not quite what you intended with the question, but I always have fun poking at metrics like that. It's notoriously difficult to create a good objective definition of "good," especially when time travel is involved) [Answer] Looking at this [list linked by SpaceLizard](http://popten.net/2010/05/top-ten-most-evil-dictators-of-all-time-in-order-of-kill-count/) I think your best bet would be to kill Leopold II of Belgium. Since the rest of Belgium wasn't interested in colonization, he might be one of the few targets where killing one person might kill the whole Idea. Without him ~10 million people might have been saved because nobody would have started the rubber slavery in Congo. [Answer] Is not clear to me if in your question you are referring about human lives, or if with "lives" you are meaning live forms. also could be useful to know how accurate can be the machine at moment (if you can decide where/when to be, how accurate can I decide to be in seconds? hours? kilometres? millimetres?). Is very important about the potential of changes to do due you only have two minutes. Any way, from a general point of view, either you are talking about human life or all life forms, you can check the history and review moments that had critical impact in how people think and make decisions about how must be handled the "life" (people/forms) and do the respective checks of the history records and the real past, and after that do the respective changes. Is very important to remember that there is a big difference between history records say about the past and the "real" past, and to remember that the history is plenty of moments of big importance around big events, but the sum of "small" changes with different grade of importance to the persons/events is difficult/impossible to track by the history, and are the real process that result/impact the "big moments". So if you return several times and check several times, you can build an very important knowledge about the tiny changes to do or avoid (for example, amplify/reduce special/small inputs/outputs received of other main/incidental acts/moments that feeds crucial people/moments that will build/take ideas/projects/decisions/acts related with dramatic changes/impacts to the "life" that you are referring). In other/fewer words, you can not know just reading/wondering about history moments. you must use the time machine and travel the necessary times to know the "real" events/process that "needs" be "tuned" in order to know the answer/s of your question. Is my opinion. [Answer] I am wonder if the scenario of to save millions of people in the past from events that now we know about the past will not create in the future famine, disease and death of much more millions of people (by for example wars water/food/ground/wellness scarcity). I think that will be better the education about impact/danger of the overpopulation, and the sustainable consumption of resources. How? maybe writing a text or book, or/and some other support of media content that must be made on that moment (with a machine/system that can create in that moment the message, using resources/systems of that time (ink, water, sun, paper, etc)), and the message can be left in specific/special places (or everywhere if you can travel several times), with content associated with the evidence about events that will happen in the future and also knowledge about how to handle/change the future in a sustainable ways. [Answer] If you simply want to preserve numbers regardless of politics, ethical considerations or anything else, you could kill Einstein. Then the atomic bomb wouldn't be made. It wouldn't be dropped on Nagasaki and Hiroshima and many Japanese people would have survived. > > A uranium gun-type atomic bomb (Little Boy) was dropped on Hiroshima > on August 6, followed by a plutonium implosion-type bomb (Fat Man) on > the city of Nagasaki on August 9. Little Boy exploded 2,000 feet above > Hiroshima in a blast equal to 12–15,000 tons of TNT, destroying five > square miles of the city. Within the first two to four months of the > bombings, the acute effects of the atomic bombings killed > 90,000–146,000 people in Hiroshima and 39,000–80,000 in Nagasaki; > roughly half of the deaths in each city occurred on the first day. > During the following months, large numbers died from the effect of > burns, radiation sickness, and other injuries, compounded by illness > and malnutrition. In both cities, most of the dead were civilians, > although Hiroshima had a sizable military garrison. > > > <https://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki> > > > ]
[Question] [ I saw a couple other threads with slightly similar questions. But I want to stress with this one, that the focus is what instrument and instrument family would be the easiest to build anywhere in the world if we started from the beginning of human civilization again. Also, definite pitch capable designs only! Even if it’s only capable of one pitch at a time. [Answer] End-blown flutes are very easy to construct from readily available materials. You only need a reed or other hollow-stemmed woody plant, with some way of cutting and shaping it (stone tools will suffice.) You can either make a set of pan pipes, with the different lengths forming different pitches, or make finger holes to create something like the North African/Middle Eastern Ney. Transverse flutes and fipple flutes are also easy to design, and were made (for example from bones of large birds) in prehistoric times. [Answer] Flutes and Drums Flutes are the oldest known instruments in the archaeological record. Some date back up to around 50,000 years old! Also, it's argued that Neanderthals made <https://en.wikipedia.org/wiki/Paleolithic_flute> It's also thought that a prehistoric flute can be attributed to neanderthals though this is debated. <https://www.nms.si/en/collections/highlights/343-Neanderthal-flute> No pitch but drums have probably been around for similar periods of time, in the form of skins stretched over stuff and banged, but these soft materials don't preserve through time in the archaeological record so we can only speculate. [Answer] [Pan Pipes/Flutes](https://en.wikipedia.org/wiki/Pan_flute) [![Andean Pan Flute](https://i.stack.imgur.com/EHfzU.png)](https://i.stack.imgur.com/EHfzU.png) or [Wood Chimes](https://en.wikipedia.org/wiki/Tubular_bells) [![Wood Chimes](https://i.stack.imgur.com/VdZ4J.png)](https://i.stack.imgur.com/VdZ4J.png) They can be made with a number of naturally grown hollow plants. Materials available all over the world, require minimal tools to construct, and require no complex assembly. You don't even need to space or cut complex holes for multiple notes, just trim to length to tune. [Answer] ### Literally Everything Less Electric Pitched Percussion. This is simple! If your world is Post-Pockyclyptic, then you've got loads of already existing metal, stone and wood bars around. You just need to harvest, shape to the desired form and carve down or add mass to tune. Add some carved sticks and connecting strings and you've got a carillon. Even if your setting is naked humans dropped off on a new planet, it only takes very basic skills to shape bone, wood, stone and leather into fully functional and well tuned xo-phones. A hollowed log, a piece of prepared skin and some ropes are enough to make a tunable drum! Metalwork can get you nakers and timpani. Bamboo, long hollow bird bones, clay, hollowed wood all make the basis for wind instruments. With very basic metallurgy you can fashion simple system flutes, clarinets, oboes and cornetts. The better your woodworking skills, the bigger the instruments you can make. But really, anyone can make a well tuned whistle or flute or shawm from a piece of pipe and a reed. Wood and horn and some basic techniques can yield you a pibgorn, a cornett, an oliphant; add some leather for bagpipes and the like. A smallish log can give you the basis for a dulcimer, a harp, or a zither. You've got many string choices from gut to silk to other plant fibres. Add a little metallurgy for brass strings! As your woodworking improves, you can thin the walls of the instrument body and make any stringed instrument that exists now. Even keyboard instruments are not beyond reach! You won't be able to make a modern piano until you get cast iron and steel, but harpsichords, clavichords, regals, organs, harmoniums, wheelharps are all within reach once you've got carpentry skills and some decent tools. [Answer] For a percussion instrument with definite pitches, try a xylophone. The difficult part is simply to carve a suitable piece of wood so that it makes the desired note when struck. Once you have a set of these pieces of wood, you can place them on straw to create a strohfiedel. [Answer] See the Wikipedia article on the [Chelys](https://en.wikipedia.org/wiki/Chelys). This was an early form of lyre. A myth (there are many variations) had it that Hermes found the dried corpse of a tortoise that had dried in the sun, leaving seven fibres stretched across the shell. That does not explain how the lyre got its extended neck, but once you have the basic idea, the rest follows. Another possibility if resetting the world left lots of scrap metal is the [Mbira](https://en.wikipedia.org/wiki/Mbira) or Thumb Piano. Africa had these for thousands of years. They can use wood instead of metal. [Answer] One more instrumen I can think of is the Kalimba or its close relative the Mbira. A series of metallic spikes of different lengths generate different pitches when plucked or striken. A wooden box would serve as a resonator and metallic spikes are scraped from older artefacts. How far the civilization is "reset" can determine how adept this civilization would be in processing the metal ores and from what sources. On the other hand, wooden spikes, presumably bamboo, have been used for the task as well. See the history of the tool here [[source]](https://en.wikipedia.org/wiki/Mbira) [Answer] I understand that stringed instruments have already been suggested, but this answer aims to specify a motivation for them, though speculatively at best. If the world reset, I'd wager that hunting would be important again and I would assume that bow and arrow designs would be developed rather quickly. Of course this depends on how much history and folklore is available. But it's easy to see that different sized bows, custom made for different hunters or for different purposes, would make different sounds when the strings are plucked. Assuming further that a good hunt, and given that cooperative hunting is much simpler and lower effort than farming for small, clan like pockets of humanity, leads to leisure time ( personally I think our common intuitions about modern society and the role of farming are short sighted ). I'd also guess that variations on bows to make different sounds would be considered. Animal calls and bird songs are natural and serve to inspire curiosity and creativity in humans. So it's not a big stretch to imagine stringed instrument abstractions, along with the sounds that we hear in sea shells, and so on. All simply ripe for the fertile mind to play with. [Answer] Slit drums produce different pitches when struck at different points. Lots of hollow/semi-hollow logs occur naturally that work as slit drums; deliberate construction is just a tiny step from that. [Answer] ## Clap Sticks [![https://en.wikipedia.org/wiki/Clapstick#/media/File:Didgeridu_and_clap_sticks.jpg](https://i.stack.imgur.com/iCZXW.png)](https://i.stack.imgur.com/iCZXW.png) Sure, pipes, flutes, ocarina, drums, etc. are going to be pretty easy to makes once you get past your basic survival needs, but they still require time and tools to make, and in those first few years when every hour spent crafting must be spent in the name of survival needs, setting aside the time to make even a simple flute will be a luxury not worth taking. However, there is one common tribal instrument that takes no effort at all to make: clap sticks. All you need to do is pick up two sticks and knock them together. At most, you will need to spend 5 minutes scraping off any excess shoots and bark. When you clap them closer to your hands, they make a higher pitch sound, and when you clap them closer to the ends they make a lower pitch sound; so, they are not specific pitched instruments, but the pitch a good clap stick makes is definite. Also, unlike most other instruments, you don't need to finish it to use it. Over time, you can refine your clap sticks in small incremental steps. You may at first start off just taking any sticks from your nightly firewood pile. Over time the sticks that make more definitely pitched sounds get kept and the less-definitely pitched sticks are returned to the your firewood pile. So before long, you will have some nice, straight, dry, knotless hardwood sticks pulled aside for your nightly jam sessions without having to invest any real work into making your instrument. ### Clarifying Definite Pitch Since this is not a common term outside of music theory, I believe there is some confusion about what this means. Definite pitch means that a sound follows a wave pattern that is all more or less one pitch like a key on a xylophone. An indefinite pitch is like the sound of a tambourine or rattle where the sound it makes is a wide range of simultaneous pitches. Tuned/tunable instruments are called specific pitch instruments, but there are also a wide range of unspecific, definite pitched instruments which includes most slapsticks, hand drums, etc. Instruments that are not both specific and definite pitch are often called unpitched instruments. But Google does not seem to know the difference; so, when you look up if certain instruments are indefinite pitch, you will often get answers for unpitched instruments instead; so, if you Google clap sticks, the results you get can be very misleading. This said, slapsticks can be either pitched or unpitched based on thier design and use. If they are straight and made out of an aged homogenous wood like oak, they will be pitched. If they are bent, tapered, greenwood, or made out of a stick with distinct heartwood and sapwood like hickory, then it will make an less pitched sound. The technique you use can also make a difference between if you get a definite or indefinite pitched sound out of them much like how a drummer can get either a definite or indefinite pitched sound out of a djembe, though generally speaking, the term definite pitched instrument just means that it CAN make a pitched sound, not that it always will. ]
[Question] [ I finally figured out how my alchemy system works. The problem is, when my characters perform alchemy, they release loads of hydrogen gas. Why? Well, basically, they will take an object and cause every atom in that object to release one neutron or proton. As the protons leave the atom, they capture an electron, forming a hydrogen atom, and then meet up with other hydrogen atoms to form H2 gas. When Neutrons are released (magically) they decay into a proton and electron which then come together to create a hydrogen atom which then combines with hydrogen to create hydrogen gas. Given this fact, I assume you can guess why my version of alchemy produces lots of hydrogen gas. The problem is, they live on a planet with an earth-like atmosphere, so that hydrogen gas can cause a massive fire if it just interacts with the oxygen, so my alchemists need to be very careful to not blow things up. Besides this, they may also want to store that hydrogen gas they are producing cause it could be useful, but how do they do that safely... Without blowing things up? Particularly how do they store this volatile material in the pre-modern era, or atleast prevent it from starting fires. There are no other relevant magical abilities I can think of which can be used to control the gas. [Answer] A balloon Provided your people do not (yet) use alchemy-generated hydrogen as fuel, so they don't actually need to store the thing, make a balloon, fill it with hydrogen and employ as a zeppelin, or outright release into the heights, the balloon would then explode from inner pressure releasing hydrogen far from inhabited zones. Pros - released hydrogen will not cause fires, as it's lighter than air. Cons - you have to catch the balloon's shell somehow, maybe not a good thing in a medieval society. Gas burner If there is a place where alchemy is performed routinely, a gas burner running on hydrogen contained in a glass dome would just do, a free advertisement, water generator, power generator (eventually), a light source and even a stove if needed for mundane use. Pros - you don't store, you burn in a controlled manner, so this "store" is almost infinite. Cons - you might need heat sinks to not overheat the lab should your alchemists overdo material conversion in a short timespan. As a side effect, your alchemists might also design reverse-alchemy magic process that consumes hydrogen from the surroundings, and creates heavier elements, say copper out of iron in three steps, a large glass dome (a size of a house) could fit for both purposes. And as a detector, a methane/hydrogen balloon could be used, weighted so that it always floats at lower bound of hydrogen within the dome, if it goes too low it's time to burn some gas. Put it under pressure Hey, thick iron canisters don't require too modern tech, just add a valve and a pump. Use a low pressure holder like the dome, then start the pump to collect the gas into a smaller canister, then use as required in labs (normal) or plain sell as fuel. [Answer] This was done in Victorian times. Early chemistry included producing hydrogen gas in bell jars to collect it. Limelight burners used in theaters were oxygen-hydrogen lamps and they used animal skin or rubberized silk bags to hold both gasses. they leak so they can only store it for a few hours to a few days at most. gas bags were not new technology, remember hydrogen filled balloon date back to the 1700's [limelight](https://www.binghamheritage.org.uk/history_of_bingham/victorian/limelight.php) [first hydrogen balloon](https://airandspace.si.edu/collection-objects/inflation-of-first-hydrogen-balloon-by-j-a-c-charles/nasm_A20000463000) EDIT Gasometers were essentially large wooden tanks (built similar to how water tanks are built but double walled), with a water seal at the bottom. these are used to store gas on an industrial scale. Probably too big for your alchemist but a smaller version can easily be built. Smaller ones like the oxygen tank below did not show up until the 1800's but could still be built with earlier technology. [![enter image description here](https://i.stack.imgur.com/9Nt6p.png)](https://i.stack.imgur.com/9Nt6p.png) [![enter image description here](https://i.stack.imgur.com/xmR5Q.png)](https://i.stack.imgur.com/xmR5Q.png) [Answer] Salt Casks We're already looking to the cask's big brother to store hydrogen today. > > Salt caverns are artificial cavities which are created in geological salt deposits. Future caverns are generally located at a depth of 500 to 1,500 metres. They are three times higher than the Arc de Triomphe. To create such a cavern, it is first necessary to drill into the salt. The second stage consists in injecting water into the salt to dissolve it. The resulting brine (water mixed with salt) is extracted and leaves room for a large, tight cavern where hydrogen can be stored under pressure. ([Source](https://innovation.engie.com/en/articles/detail/hydrogen-underground-storage-salt-caverns/25906/general)) > > > It all started when humanity needed a place to store vast amounts of excess natural gas. > > The first use of a solution-mined salt cavern for storing natural gas was in 1961 when Southeastern Michigan Gas Co. leased, from the Morton Salt Co., and converted an abandoned salt cavern formed by routine brine production. ... > > > The first such cavern created specifically for the storage of natural gas was constructed by the Saskatchewan Power Corp. and became operational in 1961 The 290,000-bbl cavern, located in Melville, Sask., was constructed in the Prairie Evaporite salt formation at a depth of approximately 3,700 ft. > > > In the U.S., the first solution-mined salt cavern constructed specifically for the storage of natural gas was completed in the Eminence Salt Dome in Covington County, Miss., in 1970 by Transcontinental Gas Pipe Line Corp. ([Source](https://onepetro.org/JPT/article-abstract/24/11/1299/163923/Eminence-Dome-Natural-Gas-Storage-In-Salt-Comes-of?redirectedFrom=fulltext)) > > > But humanity's reason for not doing it until 1961 had nothing to do with the technology needed to form the caverns. Humans have been mining salt underground for 7,000 years. > > The history that salt mining in Hallstatt looks back on, is absolutely unique worldwide. During the Neolithic Age – an almost incomprehensible 7,000 years ago – people were already busy here mining for salt. That makes Hallstatt the oldest salt mine in the world! ([Source](https://www.salzwelten.at/en/blog/hallstatt-saltmine)) > > > In other words, we didn't put two and two together until we had an excess of gas we needed to store. After we figured that out, the leap to hydrogen was logical. But your people have a reason to deal with the need to store gas at a much earlier time! Luckily, the tech for creating the cavern is literally neolithic. The problem is the tech sealing the entrance. But I think there's a logical jump to be made here, too, because your earliest alchemists — not knowing yet what the consequences of their efforts could be — lost a few limbs before realizing they needed to contain the effluvia of their efforts (and they were tired if sounding like chipmunks, anyway). But like all good innovators, they weren't trying to move mountains first. They were trying to do small things requiring small capture. Thus was born the salt cask. A bottle or box a quarter to a half cubic meter in size for which someone discovered that a concoction of (oh, yeah!) tree sap, frog guts, shredded hemp, and a pinch of fine silica could seal in place the openings with small metal disks and simple valves. Once you have it working for a cask, the move to a cave is just a matter of logistics! Well... and bricks. Lots of bricks. [Answer] > > Particularly how do they store this volatile material in the pre-modern era, > > > 1. In metal. This can be extremely thin. Beaten gold leaf shells over a support of your choice may work. Any other cheaper and available metal will work. Hydrogen diffuses into metals, embrittling them. Probably not a major problem in the short term. 2. Glass. Of a number of sorts. Again, thickness not a major issue. [Answer] Store the hydrogen as water (by "burning" it in the presence of oxygen), and release it as-needed via electrolysis. You'll want to control the rates at which oxygen & hydrogen interact with some narrow glass tubing, possibly joining the oxygen & hydrogen lines (or normal-air & hydrogen lines) at a flame to kick-start the reaction. (Think "pilot light on a gas furnace".) As long as you don't have large build-ups of hydrogen, you needn't worry about explosions. [Hydrogen readily diffuses through solid materials](https://physics.stackexchange.com/a/587221/37449), but storage via chemistry avoids that, and [electrolysis has been possible since the late 18th century](https://en.wikipedia.org/wiki/Electrolysis), with chemical understanding of it growing over the next few decades. [Answer] # Not so much of a problem Looking at experiments with hydrogen tanks that crack, releasing a huge amount of easily 700bar pressure hydrogen we can see it's pretty safe. Hydrogen is much lighter than air, being the lightest element in existence. This makes it move up into the air and dissipate at a high rate. It is also a nontoxic gas, so you need to do something very wrong to get killed by it. Your experiments shouldn't release anything close to the amounts of a pressurised tank at once, meaning you have much less risks here. Probably even in not well ventilated area's theres little chance of problems. If you're still uncomfortable, make sure any gas can easily leave your area. High ceilings and proper ventilation will probably do the trick. Though I have to say that Hydrogen gas is so small it is hard to contain. Even in a small area at the amounts you're likely to produce it will move through roofs and walls before any 'dangerous' build up can occur. That is if it doesn't react with oxygen before that to create a nearly insignificant amount of water. All this is assuming you do not want to use the hydrogen for anything and need to store it. [Answer] The hydrogen and oxygen that are reacting here will produce water vapours. Although that wouldn't be dangerous enough, but the vapours may be hindering your alchemical work. If you were to keep the container open, the hydrogen will react with the excess oxygen outside. So keep the container tightly closed and whatever oxygen is present inside, will react with hydrogen to produce water vapors. You can easily rid these vapours by placing a good chunk of water adsorbing substance like calcium chloride. As more and more water is adsorbed, more hydrogen and oxygen will react according to [Le Chatelier's principle](https://en.wikipedia.org/wiki/Le_Chatelier%27s_principle) and finally when you open the lid, there will be no leftover hydrogen that may explosively react with atmosphere. ]
[Question] [ I want to make my unicorns use the horn as their male genital. Is it biologically possible to put the genital on their head? I know there are many strange genital locations for animals, for example, the kangaroo, and i know there are many strange shapes and numbers for animals genitals, but so far I have not found any with genitals located on their heads. My design is that their genitals are covered with ceratin and spiraled (like pig/duck genital) but more compact to look like narwhal horn. Their testicles are either inside (like dolphin/lizard) together with their brain or covered with another layer of skull in their head. If this is impossible or can damage their brain or something. then I guess I just put it around their neck (think of chicken wattle) or put it in the standard horse location so this testicle hangs more outward like most common mammal testicles organs. But in any case, the genital is still on their head disguised as a horn (or what human think as a horn). [Answer] There are all kinds of ways to have sex in the animal kingdom. Spiders, for example, don't have intromissive sex, but instead the males [deposit some sperm on a pedipalp](https://animals.howstuffworks.com/arachnids/spider8.htm) and then post it into the female's genital opening (let's ignore the spiders who tear off said pedipalp and offer it to the female to use herself for now, as that probably isn't the sort of courtship you're after). Many cephalopods are similar, with a dedicated arm (the [hectocotylus](https://en.wikipedia.org/wiki/Hectocotylus)) used for handing over a blob of sperm (or again, to be torn off and handed over). If your unicorns used a similar approach, the genital plumbing could therefore still be in the regular place, but the male unicorns would need to be flexible enough to reach their horn back and spaff on it, or perhaps make a deposit on some other convenient surface and pick it up with the horn. They can then use the horn to deposit the sperm where they see fit. This avoids the need to take up precious head real estate with various glands and tubes and all the rest of the infrastructure usually associated with sperm production in mammals. If you were interested in something a bit more gristly, a hard and sharp horn at the front end of a strong animal and backed onto a pretty tough skull might be used for [traumatic insemination](https://en.wikipedia.org/wiki/Traumatic_insemination). This would be a rough proposition for the female, but you'd also have to worry about any animal capable of surviving being run through the abdomen by a big spike. They'd be a bit dangerous to hunt, I'd bet... [Answer] ### It's possible...on Snaiad Is is structurally possible? Sure, why not. But it it evolutionary plausible? Not likely, at least not on this planet. The vertebrate body plan is pretty solidly set to have the genitals on the back end of the animal, and from fish to mammals, there is no example that breaks this rule. It takes a pretty severe mutation to stick the reproductive system on the head, and the chances of this resulting in both a functional reproductive system and a functional head (both absolutely necessary for reproduction) is basically zero. There are other animals that have their genitalia in odd places, but these tend to be animals with drastically un-mammalian body plans (like snails, starfish, and squid). The chances of any one of those evolving into something resembling a horse is...very, very low, especially when they have to compete with existing vertebrates. But on a planet with a completely different evolutionary lineage, it's not out of the question. [Snaiad](https://canopy.uc.edu/bbcswebdav/users/gibsonic/Snaiad/snduterus.html) is a speculative evolution project describing a planet where the dominant animal lineage evolved from a creature not unlike the Earth barnacle, which was mainly sedentary and used its long, extendable genitalia to seek out mates. Over time, the genitals developed more advanced sensory organs, essentially turning into the creatures' heads. Descendants of these creatures eventually grew mobile and became animals analogous to vertebrates, while retaining the a body plan that placed the genitals and the sensory organs on the same appendage. Your unicorns would fit perfectly well on a planet like that. [Answer] Where would the female organs of that species be? Horn-like penis still would work like a penis -it would be supposed to be inserted to do its job. I'd say not into the skull of a female. The closer to female's uterus the better evolution-wise. Also genitals tend to be located in safe places, where they are not endangered by an accidental tear-off. Horns on the other... hand are usually located atop of a very much used head. In case of horse-like creatures they are used to bash each other brains off. You'd just make all the manly unicorn jousts... gay. Well, they ARE unicorns... I really think what Starfish Prime said about just making it a pipette would be the best way of handling it. I only am afraid that it could make the older males unable to reproduce due to having more used horns. I mean they would obviously use it for things other than semen-handing. It'd be located on their main environmental probe. They'd scrape bark off the trees, dig holes, use in mating season fights. Maybe the species would just mutate faster without the old specimens handing out the same set of DNA over and over till they are too weak to stand. [Answer] First off, it's good that you are exploring different concepts, so definitely keep it up. That being said, I think you might get benefits from trying to answer some questions when you're tackling the idea of cranial-genitalia unicorns (heretofore referred to as CGUs). Maybe just think about this stuff in your notes outside of the main content — otherwise you might run into some problems later when writing story details: Consider These Questions to Answer for Yourself and Make Your Writing Process Easier * Why did the CGU evolve to have its genitals on its head? If it was a random mutation, then why did it succeed while the other unicorns died out? Are there lots of fossils with unicorns that would have side genitalia? * Is the sex organ still made of keratin (the horn/fingernail/hoof/hair protein)? If so, why not hoof genitals or some other form? * Are there "traditional" unicorns in the same universe, and do they ever encounter the CGUs? If so, can your characters tell the difference or does it not matter? * Is there an additional hole in the skull to let the veins, vesicles, and other stuff (ask a reproductive biologist) pass through? * Does making the horn a genital change how people in the universe use or relate the horn in lore-based or practical terms). For instance, some Earth humans kill endangered animals to use their horns as aphrodisiacs. Would your characters do this, or would that be too on-the-nose? * A CGU gets in an accident where its horn breaks off. Does it grow back like deer antlers do? Can it still produce offspring? Finally, and this is the most important question: How do CGUs add to the story that you want to tell? If it's just there as a sort of random detail, then it might seem out of place. I think you should go for whatever you want, but you still maybe ought to consider how your reader or audiences will receive it within the surrounding context that you've built. One good way to troubleshoot tough story details is to imagine yourself talking (as the author, local deity, another character, or whoever) to the character you're considering. For instance, if a CGU could talk (some fantasy unicorns have that ability) what do you think it would have to say about where its genitals were? Would it complain about them or have special problems? By answering these kinds questions, you can hopefully build a rich story environment, although it definitely seems like you're well on the way already. Have fun. [Answer] ## Have the horn be an additional method of impregnation, rather than replacing the current method As others have pointed out, yes it would be possible, but the horn would be very exposed and, if they are also used for defence or duelling, then they are put in a lot of unnecessary danger. What i propose is to make the horn more of an additional form of impregnation, rather than the sole method. Many animals, such as sharks and snakes, have two sets of “equipment” (though normally these are located next to each other, there is no reason they couldn’t be in different places). A unicorn would probably have similar equipment to a horse - though likely smaller if the horn is meant as the primary method of impregnation. Im not sure how feasible this is but having a secondary reproductive system as a back up seems logical - especially if the primary system is at risk of damage. --- ### The horn might be like a snail’s love dart Alternatively, the horn may be akin to a [snail’s love dart](https://en.m.wikipedia.org/wiki/Love_dart) in that it is used prior to insemination, inserting hormones into the female unicorn to create more favourable conditions to increase the chances of successful impregnation. If this were the case, I feel it would make a lot more sense for several reasons: Firstly, although the horn is used in reproduction, much like a snail’s love dart, it is not strictly necessary - it simply increases the chance of insemination being successful. This means that having the horn exposed and using it for duelling is not as risky as they are not fighting with an organ that is necessary for their survival. Secondly, it means that the horn can be far stronger as it does not need as much soft tissue inside of it. All it would need is a channel through the middle of it to allow fluids to pass through, much like the teeth of venomous snakes. So, if the horn is stronger, it further reduces the risk of damage and also reduces the need for it to be protected (allowing it to be very exposed on their heads). Thirdly, because the horn is now just for inserting hormone-filled fluids, it shouldn’t need to take up as much space inside the unicorn’s head. Also, there is some real life precedent for this as the venom tubes for snakes runs through their head: [![the anatomy of a snake’s head, showing how the venom gland is located in its head and the tubes run under its brain](https://i.stack.imgur.com/f4cSW.gif)](https://i.stack.imgur.com/f4cSW.gif) Source:<https://thebrainbank.scienceblog.com/2014/12/01/why-is-snake-venom-so-variable/> Imagine if, instead of a snake, this was a unicorn. And instead of the ducts running under the brain and through the snake’s teeth, they instead ran upwards through the inside of a unicorn’s horn. Now proportionately, the gland would be far smaller compared to the brain of a unicorn (which would likely be similar to a horse or zebra), and it would contain hormone-filled fluid rather than venom, but it would function in a similar way nonetheless. In regards to how insemination would actually work, the unicorn would first inject the hormones into it’s mate’s reproductive system, before continuing to mate like a horse would. (Or, if you felt so inclined, you could have the horn be like an injection - it pierces the female’s skin to inject the hormones into her bloodstream.) [Answer] Cranial genitalia are a reality: [Phallostethus cuulong](https://en.wikipedia.org/wiki/Phallostethus_cuulong) is a species of fish which has its genitalia under its chin. It doesn't seem impossible that such a system could be placed on the forehead or come about in a mammal. One minor problem is that it would probably result in the female organs also being in the head, which would provide a limit to the size of their offspring at birth. This would probably mean that these unicorns would have to be some sort of mouth-brooding marsupial [Answer] There are animals with genitals on their heads, but none of them are mammals. I can see no evolutionary pressure for a horse like animal's genitals to migrate to the head region. ]
[Question] [ Far in the future technology has evolved to the point that humanity is able to try and terraform something in our solar system. The moon is out, since it's too close to earth and therefore to risky, since we don't want any debris raining down on our home (assuming we use techniques like dropping comets and such). Also, all governments are already invested with industry on it and don't want that destroyed. Mars is out, too, because we already established colonies of domes there and no one wants these destroyed / or unusable for a time either. Which other place in our solar system is most suited for terraforming? There are a lot of Saturn's and Jupiter's moons mentioned in the general listing of possible places, or Venus, but I have not been able to find an answer of the "most fit" or "least work to do". Edit: This question aims specifically towards terraforming and not only colonization. Edit II: And this question excludes earth as an answer as well. In my understanding the word terraforming (="to make like earth") implicates that earth already exists. A good point that there is room for improvement, though. [Answer] I know you said "But mars is out" But it really isn't. > > Mars is out, too, because we already established colonies of domes there and no one wants these destroyed / or unusable for a time either. > > > You probably didn't establish colonies of domes. If you had the materials to withstand micrometeorites and the radiation issues from being on the surface of mars, then you've basically either already solved the terraforming issue on mars, or you've got the technology to terraform most arbitrary bodies in our solar system. Just building domes in an un-terraformed mars is far more likely to result in habitats becoming "destroyed or unusable for a time" because of collisions with micrometeorites not burnt up in a thick-ish atmosphere and radiation frying hardware, people, and the structures themselves. You know what stops these two issues? Lots and lots of rocks. What you would have probably built were underground structures, full stop. No radiation issues, no meteorite issues, and you don't even have to terraform. This also presents even less issue to worry about terraforming making the colony structures unusable. As for the terraforming issues of mars, people often cite solar wind as a huge hurdle for terraforming mars due to its thin atmosphere. Solar wind has the effect of exciting air molecules enough to escape the gravity of a planet, and presents a radiation risk, but it appears that [there are reasonable solutions to this problem](https://en.wikipedia.org/wiki/Terraforming_of_Mars#Magnetic_shield_on_L1_orbit) ie not outside of current tech. > > During the Planetary Science Vision 2050 Workshop[23] in late February 2017, NASA scientist Jim Green proposed a concept of placing a magnetic dipole field between the planet and the Sun to protect it from high-energy solar particles. It would be located at the L1 orbit at about 320 R♂. The field would need to be "Earth comparable" and sustain 50000 nT as measured at 1 Earth-radius. The paper abstract cites that this could be achieved by a magnet with a strength of 1–2 teslas (10,000–20,000 gauss).[65] If constructed, the shield may allow the planet to restore its atmosphere. Simulations indicate that within years, the planet would be able to achieve half the atmospheric pressure of Earth. > > > The "half of earths pressure" idea may or may not be realistic, but there are other ways to deal with this that I'll get to. Then with that comes the issue of the fact that mars's gravity is simply much weaker than earths, and particles can escape the atmosphere on their own. Combine that with the fact that mars is much colder on average compared to earth, it appears that this will be accelerated when trying to heat up the planet with the terraforming process. ![enter image description here](https://i.stack.imgur.com/shHi6.png) [Source](https://commons.wikimedia.org/wiki/File:Effect_Of_Warming_Mars_On_Atmosphere_Escape.png) I asked a question about this a while back on [space exploration](https://space.stackexchange.com/q/35736/26906), and the conclusion I got was interesting: it appears that water loss reasoning is in contention, and that the primary method of loss may have been through the weaker gravity, and [not solar wind at all](https://space.stackexchange.com/questions/8365/how-is-martian-water-lost-to-space). The loss of these particles regardless happened over [hundreds of millions to billions of years](http://crowlspace.com/?p=3149). > > At the same time that same magnetic energy release powered a much stronger Solar Wind. The protons and other ions of the Solar Wind cause all the non-Jeans Escape processes listed in the Table above. Collectively several metres of water and perhaps 80 millibars of Carbon Dioxide would be lost over 4.2 billion years – at current rates of loss. As the bare minimum for terraforming is about ~300 millibars of carbon dioxide (equivalent to about 250 millibars of Oxygen) this doesn’t seem like a show stopper for terraforming. If we can supply modern day Mars with *~300 millibars in a few hundred years, then replacing 80 millibars in 4 billion doesn’t seem excessive. > > > If we were to provide mars with atmosphere, it might go away in 500 million years, but is that really that big of a deal on a human timescale? So solar wind is not a problem on mars. Neither is losing atmosphere we get on mars. So what are the issues left? Atmospheric pressure * Inert gas composition * Sunlight * Temperature * Plantlife # Atmospheric pressure With out proper atmospheric pressure, water, and you, will boil when exposed to the martian atmosphere directly. Liquid water will just boil off which is a non starter. If the lagrange point solar wind protector doesn't actually build up the atmosphere to half of earths, then here are your other options: * you'll need to manually use mars's own materials to do so ie through some industrial extraction. This is probably possible in human timescales but there still may not be enough atmosphere. * you'll need to crash meteorites into mars to release enough gasses. Your colonies should probably be fine (they are underground after all!), and if you already have meteorite mining tech, you shouldn't have too much trouble making this happen. It will just take a long time to take asteroids off course to make them land on mars (100 years), and cut them up into enough smaller pieces that they don't accidentally blast more molecules than they insert onto mars, and don't put giant holes in mars itself. This is also farther outside our current tech. * you'll need to transport gases from other planets instead of meteorites, this could take a bit longer, depending on how feasible it is to capture these gases and move them to mars. This is also pretty far outside of current tech. You can also do any of these solutions part way, and then dig a deep hole in the planet, where air pressure is large, making open air environment at least for the hole you made in the ground. If you, say, could only manage to make mars's atmosphere 1/8 of air pressure at normal breathable points (ie 1/8 \* 500 millibars, not the full 1000 at sea level, aka 62.5 millibars), you could actually just dig a hole so that you had 8 x the amount of air above you that you would have at sea level. That would be a really deep hole, but with much less volcanic activity, it is possible you could dig many times deeper on mars than you could on earth with out heat issues, and with less gravity, rocks may be easier to get through at a certain level. You could then wait for a full terraform if need be. Increased pressure from above should make air below even more dense at higher pressures, so I don't believe the hole would need to scale linearly with the mass of air above the column, ie if hole B is 2x as deep as hole A, it would have more than double the air pressure. This is different than water which mostly has linear increase in pressure because air/gas is much more highly compressible. We can see this in [this chart](https://appmeas.co.uk/resources/pressure-measurement-notes/how-is-pressure-related-to-altitude-and-depth/): * sea level is 14.7 psi, * 10,000 feet is 10.2 PSI, 4.5 psi change * 20,000 feet is 6.4 PSI, 3.8 psi change * 30,000 feet is 4.3 PSI, 2.1 psi change * 40,000 feet is 2.7 PSI, 1.6 psi change * 50,000 feet is 1.6 PSI, 1.1 psi change [![enter image description here](https://i.stack.imgur.com/dCHVI.png)](https://i.stack.imgur.com/dCHVI.png) Exponential gains would be made with deeper holes. # Inert gas composition The composition of these gases that we use to pressurize the planet also matters. The composition of the atmosphere would need a lot of nitrogen, as the rest of the gasses that might work have adverse side effects, will escape the atmosphere easier or are much harder to collect. With out such inert gases, gases like Co2 will poison us in the concentrations required to make mars with an earth like atmosphere, similar story for O2. We may be able to focus harder to find gases on mars like nitrogen in a smaller area if we use the hole idea, though we would still need some endgame to get nitrogen to the whole planet if we want everything terraformed. # Sunlight The sunlight mars receives is significantly lower than earths, [44% of earths per unit area](http://tomatosphere.letstalkscience.ca/Resources/library/ArticleId/5421/is-there-enough-light-on-mars-to-grow-plants.aspx). However: * many plants actually don't do well in direct sunlight (both in water and out) and actually prefer lower light. * plants are primarily Co2 limited in many ecosystems, not light limited. Too much light energy actually damages plants. Plants will avoid trying to get all energy in all wavelengths of light because too much energy will destroy their chloroplasts and surrounding cells. So from just the sunlight perspective, it isn't an issue for many earth plants, though they may be focused at the equator and smaller at the start. # Temperature The bigger issue here is heat (at least for plant life). Mars is [significantly colder](https://en.wikipedia.org/wiki/Climate_of_Mars#targetText=Differing%20in%20situ%20values%20have,%C2%B0F)%20at%20the%20poles.) than earth (though maybe not as cold as you would think): > > Differing in situ values have been reported for the average > temperature on Mars,[22] with a common value being −63 °C (210 K; −81 > °F).[23][24] Surface temperatures may reach a high of about 20 °C (293 > K; 68 °F) at noon, at the equator, and a low of about −153 °C (120 K; > −243 °F) at the poles > > > About the only real way to really heat up mars is to thicken its atmosphere to get a greenhouse effect. One thing to note, 95 % of mars's [atmosphere is CO2](https://en.wikipedia.org/wiki/Atmosphere_of_Mars), while 0.0407% of earths is CO2. Average surface pressure on mars is 610 Pa, but pressure is affected by many factors including temp, so this is highly inaccurate, but if you compared this directly with earths 101325 Pa pressure, if we increase the pressure on mars by the increase in gravity to reach earth gravity, (1/.38 = 2.63...) we get 1605 \* 95% to get 1525 pa, and then we get 1525/101325 = 0.01505% ... a very rough approximation of the comparison of the CO2 per unit area of mars if compared to the atmosphere of earth. This is less than half the amount of CO2 on earth. We would probably need to extract more CO2 from mars and get other greenhouse gases like methane to increase the greenhouse effect. # Plantlife Okay, assuming we solved all the other issues here, we would still have a few more hurdles: * Plants still need oxygen. * Plants need good soil/medium to grow in. The first part might be surprising, but you can actually suffocate many terrestrial plants in water if you completely submerge their roots, and especially so if you submerge the whole thing. To solve this you would need to bring [Cyanobacteria](https://en.wikipedia.org/wiki/Cyanobacteria#targetText=Cyanobacteria%20%2Fsa%C9%AA%CB%8C%C3%A6,%2C%20romanized%3A%20kyan%C3%B3s%2C%20lit.) to mars (aka blue green algae). This isn't a big deal (cyanobacteria multiply fast) except you would need to have lots of water surface area for them to colonize. You would then need to create an equilibrium with plants quickly after. You would probably need to grow both in isolation before releasing to make sure you hit a good equilibrium (not suck all the co2 out of the air and leave none for the plants). Then you could introduce other kinds of co2 producing organisms, probably more than just people. We'll get to this in a bit. Soil is another story. You can't just use martian soil because it has virtually nothing that plants can use and is toxic to most [plants and living organisms](https://en.wikipedia.org/wiki/Martian_soil#targetText=The%20levels%20detected%20in%20the,are%20also%20toxic%20to%20plants.). Now, if you completed the previous steps, you might have lakes/oceans which might be big enough to cover lots of the [planet with 35 meter oceans](https://en.wikipedia.org/wiki/Water_on_Mars#targetText=A%20study%20in%20June%202010,have%20covered%2036%25%20of%20Mars.). This is fine, we don't need the Mariana trench for this to work. Then instead of putting plants in soil, you can just use water plants/algae for the time being, where the cyanobacteria are sitting. In addition to that, we'll need organic material to fertilize the plants. This comes from both the cyanobacteria and invertebrate aquatic organisms that can feed on algae, like [daphnea](https://en.wikipedia.org/wiki/Daphnia#targetText=Daphnia%20are%20members%20of%20the,to%20freshwater%20lakes%20and%20ponds.), but might even include snails, shrimp, etc... These can grow and exist in extremely limited environments already. These animals are already used to living in environments that emulate "low G" (water), thus should at least feel quite at home in martian gravity. They also require very little to live. A small 20 ounce cup with algae is enough to sustain these creatures (though they also need a proper atmosphere). What will happen is the waste from these creatures will be used the fertilize plants, and will gradually build up on shores, where other types of plants will eventually be able to take root, and a slow process of plants + other animals being introduced will allow finishing the terraforming process. The hardest part for us right now is air pressure, assuming we can't find proper gas sources for this on mars. Otherwise we might actually have the technology, or close to it, today to complete this process in a couple hundred years. [Answer] If you want an Earthlike planet, and Mars is out, [Venus](https://en.wikipedia.org/wiki/Venus) is the only option. No other rocky body has gravity high enough to hold an atmosphere, especially close to the Sun where the solar wind is strong. (Titan is far enough away to not make this an issue, but it is VERY cold). It won't be easy, though. It would require removing most of the atmosphere, which has a mass 93 times that of Earth's and consists mostly of carbon dioxide (96.5%) with the remainder being nitrogen. You would want to keep the nitrogen and remove all the carbon dioxide, but this sort of filtering might well be practically impossible. After that, you would have to add oxygen, though it is possible that the introduction of algae could turn some carbon dioxide into oxygen. Venus is also way outside the habitable "Goldilocks" zone (too close to the sun), so it would either have to be moved quite a bit farther out (a huge endeavour) or be shielded from a lot of the sunlight it receives, e.g. with orbiting reflectors (which could double as energy collectors). Venus also rotates very slowly, making for very long days and nights (there are two days to a Venus year) with extreme temperature differences between day and night. I suppose some of the solar reflectors mentioned above could direct some sunlight to the night side, but this would go against the purpose of limiting infall of sunlight. It might be feasible with sufficiently advanced technology to direct a large number of comets towards Venus, where they would impact off-centre, increasing the planet's rotation while adding water to the atmosphere and eventually the surface. Hopefully, these impacts could strip off some atmosphere as well, but you would probably also need to kind of atmosphere cannon that compresses the carbon dioxide and shoots it off the planet. A problem may be that, given the mass of Venus, more comets would be needed than exist in the solar system without going out to the [Oort Cloud](https://en.wikipedia.org/wiki/Oort_cloud) (which is very far out). Then there is the problem of Venus' very weak magnetic field, which provides negligible protection against cosmic radiation and particle radiation from the sun. Even if you provided Venus with an earthlike atmosphere, it would not be safe to stay outside for very long. Given all these issues, I don't think it would ever be worthwhile to terraform Venus (or any other body in the Solar System, including Mars) when it is so much easier to create artificial rotating habitats built from asteroids or [Kuiper Belt](https://en.wikipedia.org/wiki/Kuiper_belt) object. There's plenty of water ice out there from which oxygen can be created, and the nitrogen in our atmosphere could be replaced with helium, the second-most common element in the universe. The shells of these habitats would protect the inside from radiation and micro-meteorites, and you could have whatever climate you want inside. Given the amount of material to built such habitats from, you could easily house trillions of people, compared to a measly tens of billions on a terraformed Venus. [Answer] The most suitable, and underrated planet is Earth! And that's not just a joke answer. Even building habitations in Antarctica is 1000x easier to permanently settle than spending Trillions of dollars to get a manned base on Mars (or any other Solar System planet). Antarctica has breathable air. It has water. It has protection from cosmic radiation. If something goes wrong, it can be resupplied. Currently, 95% of the worlds population sits on just 10% of the land area. There are vast tracts of land still unsettled across the world. Even building floating cities on the Oceans would be far far easier than terraforming the other planets. [![enter image description here](https://upload.wikimedia.org/wikipedia/commons/thumb/6/67/World_population_density_1994.png/640px-World_population_density_1994.png)](https://upload.wikimedia.org/wikipedia/commons/thumb/6/67/World_population_density_1994.png/640px-World_population_density_1994.png) Full size link: <https://en.wikipedia.org/wiki/World_population#/media/File:World_population_density_1994.png> [Answer] If you are terraforming your first planet, you are probably K-type 1 to 2 civilization -- see <https://en.wikipedia.org/wiki/Kardashev_scale> So, Titan. Heat isn't a problem. Cooling stuff off is often harder than warming things up. Gravity is hard. Spinning up Venus, for example, is going to cost in the neighborhood of 10^29 J, or 10^12 seconds of a K1 civilization's power budget: a 30,000 year project. Serious terraforming takes serious energy. And serious energy makes being cold a trivial problem. The two hardest things are (a) getting rid of waste heat, and (b) gravity at a K1.5 civilization level. Note that fuzing multiple planets into a larger one is going to result in a lot of debris and a lot of waste heat, and as mentioned, heat is annoying to get rid of. [Answer] I question the need for terraforming at all. Venus: install an extensive network of [cloud colonies](https://www.google.com/search?q=venus%20floating%20cloud%20city&oq=venus%20floating&aqs=chrome.2.0j69i57j0l4.7549j0j8&sourceid=chrome&ie=UTF-8). Comets: specifically, [Dyson Trees](https://en.wikipedia.org/wiki/Dyson_tree). ]
[Question] [ Assuming that some future civilization of hyper-advanced humans, or aliens for that matter, had the technology to reshape the solar system so that there were several habitable planets the rough size of Earth, complete with water and biospheres, how many be made using only materials from the solar system? Venus would need minimal changes besides water and adjusting the atmosphere, and Mars would be more difficult, given that it's only half the size, but it should be possible with such technology, especially since it has a good amount of water to start with, so that's three counting the original Earth, how many others could be constructed? [Answer] My best guess is the solar system has enough solid mass for 45-95 Earths, all but two of which are from the gas giants. They can get closer to 500-600 if they can convert hydrogen and helium into material the Earth is made out of. More than 300,000 if they can convert the entire Sun. However, it's unlikely you'd get more than a few to actually have biospheres if you can't convert elements to other elements, since large amounts of iron would be needed in the core of each planet to produce a magnetic field to protect the planet. Let's start with the rocky planets, since it's easy to estimate material from them. For the record, you are overestimating the size of Mars. According to the [Wikipedia list objects in the solar system by mass](https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size), Mercury gets you 0.06 Earths, Venus 0.82, Earth 1(unsurprisingly), Mars 0.11, and scraping together all of the moons and dwarf planets gets another 0.10 if you round up generously, for a total of 2.09 Earths worth of mass. Let's round down to 2 Earths(or round up to 3, this mass is irrelevant anyway). The gas giants are where the real planetary mass is: Jupiter alone would be more than 300 Earths worth of mass. However, unless your advanced civilization can convert the hydrogen, helium, and other gases that make up most of these gas giants mass into rocks your Earth collection will be a bit soft. So, we'll look at estimates for the solid material in these. Wikipedia provides estimates of [12-45](https://en.wikipedia.org/wiki/Jupiter#Internal_structure) Earths worth of solid mass in Jupiter, [9-22](https://en.wikipedia.org/wiki/Saturn#Internal_structure) for Saturn, [9-14](https://en.wikipedia.org/wiki/Uranus#Internal_structure) for Uranus, and [10-15](https://en.wikipedia.org/wiki/Neptune#Internal_structure) for Neptune. This totals up to 40-96 Earth-masses worth of solid material in the planets. If they can convert all of the gasses in those gas giants into the material the earth is made out of([32% iron, 30% oxygen,15% silicon, 14% magnesium, 10% assorted](https://en.wikipedia.org/wiki/Earth#Chemical_composition)), then you could easily get a few hundred Earths. However, all of this is irrelevant if they can convert gaseous elements into rocks: the sun alone would get you more than 300,000 Earths worth of mass. [Answer] They won't. Making entire planets is incredibly wasteful - the interiors are, for the people living on the surface, entirely useless. So what any space faring race capable of such engineering would build is something more like [IM Bank's Orbitals](https://en.wikipedia.org/wiki/Orbital_(The_Culture)). You get pseudo gravity from rotation of the ring, and you can get vast areas of land without the waste (and time) required to form a planet. Note that putting a planet together would generate enormous heat - just from gravitational compression and maybe from other processes (like colliding large lumps of matter together to form bigger masses). That heat is useless waste. If you have the tech required to do anything on that scale, you will have the tech required to build and maintain a ring more easily. Here's a quote from [a document attributed to Bank's himself](http://www.vavatch.co.uk/books/banks/cultnote.htm) : > > The attraction of Orbitals is their matter efficiency. For one planet the size of Earth (population 6 billion at the moment; mass $6\times 10^{24}$ kg), it would be possible, using the same amount of matter, to build 1,500 full orbitals, each one boasting a surface area twenty times that of Earth and eventually holding a maximum population of perhaps 50 billion people > > > So any society capable of engineering planets just won't do it as it's ludicrously wasteful. [Answer] # Earth + 1 additional Earth The limiting factor is Iron. The Earth has a lot of it, and it is molten, providing us with a magnetic field and plate tectonics. No where else in the solar system is there that much Iron. Consider that the Mass of the Earth is 5.97e24 kg, while the combined mass of Venus, Mars, Mercury, the Moon and the asteroid belt is 5.92e24 kg. That is, the Earth is more massive than those three planets, one moon, and many asteroids combined. Much of the mass of those smaller bodies is 'crust'-like materials, carbon and silicon and oxygen and what have you. The Earth definitely has more Iron than those planets combined. Without Iron, you won't have a planet with nearly the density and gravity, much less the life-sustaining magnetic field as Earth has. Other than Iron-56, no other [element in the solar system](https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements#Solar_system) is nearly abundant enough to give a newly constructed planet the density of Earth. On the other hand, how much Iron is in the Gas Giants? Who knows? We certainly don't. From the material available in the solar system outside of the cores of the four gas giants, there is only enough Iron to make one additional Earth. There may be enough material inside the gas giants to make a few more, but that is not known with any certainty. [Answer] This answer is intended as a very rough, order of magnitude estimate. My rough estimate is about 1000 Earths. This answer also assumes that elements cannot be turned into other elements and that the Sun will be used. The mass of the Solar System is approximately 1.992x1030 kg\. The mass of the Earth is 5.972x1024 kg ([Wikipedia](https://en.wikipedia.org/wiki/Earth_mass)). Then I found the relative abundances of elements in the Solar System\\* and on Earth ([KnowledgeDoor](http://www.knowledgedoor.com/2/elements_handbook/element_abundances_in_the_solar_system.html), [Wikipedia](https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements#Earth)). I used only elements with more than 1000 PPM abundance on Earth. Table: $$ \left\| \begin{array}{cc\|c\|c} &\text{Element}&\text{Solar (PPM by mass)}&\text{Earth (PPM by mass)}\\ \text{Al}&\text{Aluminum}&55&15,900\\ \text{Ca}&\text{Calcium}&69&17,100\\ \text{Cr}&\text{Chromium}&15&4,700\\ \text{Fe}&\text{Iron}&1,112&319,000\\ \text{Mg}&\text{Magnesium}&618&154,000\\ \text{Mn}&\text{Mangnese}&12&1,700\\ \text{Ni}&\text{Nickel}&676&18,220\\ \text{O}&\text{Oxygen}&8,255&297,000\\ \text{P}&\text{Phosphorus}&7&1,210\\ \text{Si}&\text{Silicon}&674&161,000\\ \text{Na}&\text{Sodium}&33&1,800\\ \text{S}&\text{Sulfur}&384&6350\\ &\text{Total}&11,914&997,980\\ \end{array} \right\| $$ I then multiplied the PPM by the masses (and divided by a million) to get the approximate amount of each element present in the Solar System and on Earth in kilograms. Then I divided the amount of the element in the Solar System by the amount on Earth to get how many Earths worth of the element was present in the Solar System. Table: $$ \left\| \begin{array}{cc\|c\|c} &\text{Element}&\text{Solar (Kg)}&\text{Earth (Kg)}&\text{Solar/Earth}\\ \text{Al}&\text{Aluminum}&1.10\text{e+26}&9.50\text{e+22}&1,155\\ \text{Ca}&\text{Calcium}&1.38\text{e+26}&1.02\text{e+23}&1,353\\ \text{Cr}&\text{Chromium}&3.16\text{e+25}&2.81\text{e+22}&1,125\\ \text{Fe}&\text{Iron}&2.22\text{e+27}&1.91\text{e+24}&1,163\\ \text{Mg}&\text{Magnesium}&1.23\text{e+27}&9.20\text{e+23}&1,341\\ \text{Mn}&\text{Mangnese}&2.44\text{e+25}&1.02\text{e+22}&2,406\\ \text{Ni}&\text{Nickel}&1.35\text{e+27}&1.09\text{e+23}&12,378\\ \text{O}&\text{Oxygen}&1.64\text{e+28}&1.77\text{e+24}&9,272\\ \text{P}&\text{Phosphorus}&1.42\text{e+25}&7.23\text{e+21}&1,968\\ \text{Si}&\text{Silicon}&1.34\text{e+27}&9.61\text{e+23}&1,397\\ \text{Na}&\text{Sodium}&6.60\text{e+25}&1.07\text{e+22}&6,136\\ \text{S}&\text{Sulfur}&7.66\text{e+26}&3.79\text{e+22}&20,212\\ &\text{Total}&2.37\text{e+28}&5.96\text{e+24}&3,976\\ \end{array} \right\| $$ This is like a limiting reagent problem in chemistry. Chromium is the limiting factor. There is only enough chromium in the Solar System to make about 1000 Earths. As the other answers mentioned, you would run out of iron very soon after and iron is more important than chromium. Reflection I think only considering these elements makes sense because these elements make up 99% of Earth. The other elements are trace elements so I don't think their exact amounts matter as much. However, trace elements are important for life so I don't know what consequences having an insufficient amount of some trace elements would have on life. These elements will still be present in the new Earths, I just can't guarantee that there is enough to put as much into the new planets as there is on Earth. There is also the problem that I think that chromium may be replaced by other elements for an Earth-like planet, but I don't know how essential that we have this specific amount of chromium. \I could not find a number but the mass of the Sun is 99.86% of the mass of the Solar System and the Sun has a mass of 1.989x1030 kg ([Wikipedia](https://en.wikipedia.org/wiki/Solar_System#Structure_and_composition), [Wikipedia](https://en.wikipedia.org/wiki/Solar_mass)). This gives us 1.992x1030 kg as the approximate mass of the Solar System. \\*I had to convert from atoms per 106 Si atoms to PPM ]
[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/57257/edit). Closed 7 years ago. [Improve this question](/posts/57257/edit) A super advanced civilization has created a machine with superior A.I. that could survive a supernova explosion from a nearby star approximately 3,600 parsecs from the Sun, the machine is programmed to harvest all available resources from the debris and other surviving planets and create an artificial planet as big as the planet Earth. The artificial planet orbiting around a yellow giant star also has layers of atmosphere mostly consisting of inert gases, my question is why would the machines which is capable of surviving in vacuum condition want[1] to experience seasons? [1] this implies a conscious decision. Would it not be better off with a constant amount of sunlight instead of occasional devastating lightning storms? [Answer] First, planets created through natural processes are nearly guaranteed to have some degree of axial tilt, which is the primary contributor to seasonal changes in exposure to parent starlight (herein "sunlight", even though it's not!). Now, you're asking why an artificial planet would have seasons (in particular, why its artificial construct inhabitants would want seasons). I can think of two main reasons: # 1. Engineering tolerance Your machines end up not caring about axial tilt because they simply don't care about seasonal fluctuations in temperature and sunlight. Being machines, they can tolerate these fluctuations without any operational impairment, so they don't care. Put another way, they want the cheapest option, so they "want" seasons by proxy: it may end up using more energy, more time, or more complicated processes to create a planet with a near-zero axial tilt, so they just go with the cheaper option that results in an axial tilt somewhere between -20 and +20 degrees, for example. # 2. Bio-fuels Even though your artificial life forms are, well, artificial, that doesn't preclude them from seeding and farming natural life. Perhaps they plant varied bio-fuel crops as an efficient source of hydrocarbons to fuel some of their processes, and those crops function better with growing seasons and off-seasons. Perhaps they farm some kind of migratory animal that needs to be migrated between grazing lands so they don't eat all the grass, and seasons are a free, sustainable way to do that. The only minor hitch for this option is that your "inert gases" in the atmosphere might not be conducive to crop growth. Most Earth crops rely on carbon dioxide, at least (that's where the carbon comes from). There are other potential reactions, of course, but that's probably a bit beyond the scope of this question. [Answer] ## Because it was There Would machines really pass up a prime choice planet just because it was slightly suboptimal due to seasonal variation? In fact, statistically all planets have elliptical orbits, it's actually the expected outcome of the [collapsing matter forming solid bodies](http://curious.astro.cornell.edu/about-us/57-our-solar-system/planets-and-dwarf-planets/orbits/244-why-do-planets-have-elliptical-orbits-beginner) ([Earth is an outlier here](http://www.godandscience.org/apologetics/designss.html), but still slightly elliptical). And that's step 1 towards having seasons--and in the case of very extreme ellipticals, are the primary factor. Step 2 is having a rotational spin that's off-axis slightly, which I'd be willing to bet, has good odds of occurring. I don't have good data on planets outside the solar system (though there are some methods for measuring it), but predominantly the reason for no axial tilt is being [tidally locked](https://www.reddit.com/r/askscience/comments/3wooz2/how_common_are_planets_with_tilts_like_ours_are/) with the parent celestial. There you go. Its going to be more likely that a planet has seasonal variation than not and the machines (whomever, really) can't be too picky choosy about where they end up. [Answer] Assuming an atmosphere, a planet with seasons is a planet with wind, so there is an easy power supply that requires no mining. They'd build it to produce constant and dependable wind patterns. This could also be in addition to any direct solar power applications. [Answer] Because shit happens Careful reading of the body of this question shows that the world isn't something the machines happened upon. It's something they built from scratch. So, given that they could fight the whims of fate and force their world to have whatever tilt they pleased why would they give it any tilt at all? Either they like having a white christmas or they did the math and figured out that the energy it was going to cost to get the perfect tilt could simply go into home heating and construction of lightning rods. This would mean the tilt had a tolerance. Once the tilt was within tolerance they moved on to making sure the fjords looked nice. And maybe they just got the math wrong. Building a planet is one thing but weather prediction is another. [Answer] One of the main problems with a tech based planet is heat distribution. By converting the Sun's energy into power, which then presumably gets used for computation and locomotion. This means the sunlight isn't getting reflected back as readily as it otherwise would and so the planet gradually heats up. With seasons you could allow one side of the planet to operate at full capacity and then cool down during the long winter. This assumes the planet doesn't have an atmosphere. With an atmosphere then the seasons would come with regular winds and shifts that could be fine tuned to create the best method of heat distribution and cooling effect. [Answer] Because they want to have a suitable warming and cooling cycle to more appropriately control the weather patterns. See a sphere due to its shape has to have calm somewhere, by disturbing the equilibrium a bit you can ensure it moves around, and perhaps you can control this. This ensures that any cooling systems work more optimally. Perhaps they have many subsystems can just harvest their energy from the ambient fluctuations so not to need build a grid for everything (they obviously could but why build a grid if you do not have to). The atmosphere itself ensures a suitable temperature ranges making material selection for systems more forgiving. But not all systems have the same optimal temperature ranges by changing weather allows you to cycle optimums. Maintenance is better done in separate season than computation. ]
[Question] [ Zombies are a grand classic of horror and fiction. For this question, let's assume we're talking about the following stereotype, as a starting point: * When you get bit you turn into a zombie * The body is dead but still able to move * Zombies can only be killed with a head shot I keep going through this and I cannot see how it's possible. Using earth-like biology (or with believable variations), how close can we get to this? Explanations are especially needed for the whole dead part: The body being dead but still moving, if possible. [Answer] [Ophiocordyceps unilateralis](https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis) is a very interesting kind of parasitic fungus. It infects ants and affects their central nervous system in a way which alters the behavior of the ant. The ant stops working for the ant colony, and instead climbs the stem of the nearest plant, which is the ideal environment for the fungus to grow. The fungus then kills the ant and eats it from the inside out. Now ants are very simple lifeforms which have no complex brains like humans. But the precedent is there. So just imagine a fungus like this which targets humans instead of ants. It infects the human brain and takes over its function to turn the human into a vessel for spreading itself to other humans. This explanation for the zombies origin was used, for example, in game "The Last of Us". Another common variant of this is a virus or bacterium which affects the brain function of the infected humans and changes their behavior to spread the infection. [Answer] Without using magic? That reduces your options significantly. First real zombies are people were drugged and kept as slaves by Haitian Voodoo. They would poison the person who would appear to die. Get buried and then were dug up and kept drugged as slave labor. Now for zombies closer to the movies, the host really can't be dead. They can be brain dead, but the body must be alive. One possibility is a bacteria or fungus that causes extreme mental issues and the ability to ignore pain, maybe able to close off arteries quickly to prevent bleeding to death quickly. Nanobots might also provide that same type thing, but a foreign intelligence (of sorts) could be replacing what was once human. Though you'd have to say that the nanobots needed the brain's pathways to control the body and when it is destroyed their control vanishes. Last, an alien life form that uses group intelligence infects humans, but isn't completely compatible so both human and alien are in a retched state, fighting for control and the body is looking for help, the aliens trying to find a viable host, the human to get rid of the parasite, by suicide if necessary. [Answer] How about a creature (plant, animal or other) that spreads throughout the body and forces the parts to move around so that the body can bite and spread the tiny creature to new hosts? That's how I always imagined it. For an example on how a plant (or fungus) may be able to do it see: <https://en.wikipedia.org/wiki/Ophiocordyceps_unilateralis> But of course it'd have to spread through a larger creature. [Answer] ### “When you get bit you turn into a zombie” Simple. Germs/mites etc. that reproduce in zombies and cause the condition also congregate in the mouth. Lots of real viruses do this. While simple, this is not a necessary feature of classic (Romero) zombies. Arguably, they spread their condition simply by inducing fatal sepsis from a mass of mundane germs. Their condition is death itself while under the influence of some unexplained cosmic force, i.e. magic. ### “The body is dead but still able to move” It would have to be moved like a puppet. This would require the cause of zombification to digest the rotting human musculature, breathing apparatus etc. and to replace these with new and effective organs. This is unheard of in nature, and not practical for a bio-weapon. I would argue that the body does not have to be dead. Settle for brain death or a debilitating change in temperament à la 28 Days Later (2002). The mites/germs rebuild parts of the brain to control the body, causing typical zombie hygiene as a side effect. ### “Zombies can only be killed with a head shot” If head shots are highly effective, that would be explained by the mites/germs using the brain in the manner of cordyceps fungi. If all other damage is less effective than it would be against a living human, that would be explained by the destruction of relevant nerves in the zombification process to eliminate pain, coupled with enough endocrinological mayhem to push the body to brief peaks of hyperactivity in search of food, new hosts etc., but a shot through the heart would still stop a zombie. A less credible disease vector could conceivably combat infections and other mundane causes of death to keep its host mobile, and clot blood better than we do, and so on. A still-less credible vector could repair its host. An incredibly fancy bio-weapon could build a redundant heart. [Answer] Imagine a nearby future where humanity has wired itself in order to better connected to the internet. Instead of needing a bulky, inconvenient computer, the signals would be transmitted directly through microfilimant cables under the skin. You would not need a credit card. Instead you could just lay your hand on an item and buy it immediately as the RF ID tag interacted with the tiny chip in your brain. Now imagine something went horribly wrong, a computer virus, perhaps, or just a EMP pulse that fries the circuitry in the brain, leaving only aggression and very basic memory functions. The new and shiny technology might turn us all into zombies, effectively lobotomizing us into aggressive automatons. The life span of these lobos would be minimal, since they would just be damaged normal people, but lets say there's an extreme adrenal response which is off the charts, so while the threat is relatively short lived, while it is active, you might have a 28 days later scenario. [Answer] The Root problem with anything except for maybe funguses is they all require a functioning body [Circulatory system, Digestive system, Respiratory System, Excretory Systems]. Without which the body simply wouldnt move and the ailment would have difficulty spreading. Not to mention in all natural cases of foreign organisms they simply do a few things to achieve their goal mostly because they have limited 'knowledge' of their host. However, this NEW concept has a few workaround to increase plausibility: ## Transmittable Brain Tumors Natural Precedence: [Lookup Tasmanian Devil Tumors](https://en.wikipedia.org/wiki/Devil_facial_tumour_disease) In the case of the Tasmanian Devil, Tumors were transferred via bites and caused horrific and ultimately lethal symptoms. However there are cool aspects about this concept that make things more possible: * As incurable as cancer * immune systems are irrelevant * greater 'knowledge' of host * certain tumors have be known to replicate other human constructs like teeth * it's a runaway mutation, which means it can be the cause to all kinds of other mutations in the body (EX: if you wanted your zombies to sprout wings this would be the way to scientifically justify it) * mutates rapidly * Tumors can also produce all kinds of substances similar to bacteria. So what if this transmittable tumor infiltrates the brain and rewires it to all the desired behaviors discovered in modern psychology. What if it could spread to the body and cause all kinds of desired or undesired physical manifestations. This too requires a functioning body, however with this there can be a cool hack around that gets closer to the appearance of death. After the tumor invades the brain it could then spread to the body and start duplicating organs. This could make your zombies more resilient and closer to the 'undead'ness of the mythical zombie. ## Key Constraints * Evolution: while cancer is a rapidly evolving illness it does follow the rules of natural selection. So in the case of zombies developing wings you would have to create a fairly long historical progressive lineage of zombies that slowly develop the traits for wings, with an ideal some making it and the less ideal some not making it. The host must also survive long enough to pass on this condition. * Metabolism: cancer can work very fast because it can develop an increased metabolic/reproductive speed, however this requires nutrition (hunger and working organs). This increased metabolic speed can be stretched for rapid regeneration. So in this instance a zombie could take apparent fatal injuries however still rise back if provided a ~day and nutrition. This falls apart if the zombie is riddled with bullets and loses too much blood thus starving all the cells. This could also explain fast and unrelenting zombies. * Starvation: an increased metabolism requires increased food intake without which the zombie would starve. It could be possible however, for the tumor to be 'smart' enough that when it senses a reduced nutrition supply to enter a dormant state halting growth/reproduction and significantly reducing the physical need for food. This would then justify slow, lethargic zombies playing possum awaiting stimuli that would indicate food. However any unhealed fatal wounds would potentially be fatal at this point. * Water/disease: Since the zombie is still 'alive' it still needs water somehow and this also bares the question of disease. The cancer is still 'human' cells which are still potentially susceptible to human infections. It's a greater stretch but it could be that it develops a mutation that alters the immune system. [Answer] Mind controlling chemicals are seemingly common in the insect world. Consider the case of the parasitic Japanese wasp vs the Orb Weaver, wherein the wasp's larvae will [force the spider to spin a web to protect themselves](http://www.livescience.com/51764-wasp-spider-zombies.html). > > The zombie slave spiders tended to build a particular kind of web, one > that was quite different from the webs created by parasitoid-free > spiders, the researchers found. First, the parasite-ridden spiders > took apart their old webs (some even abandoned them altogether), and > then they started building new ones that resembled the web an orb > weaver would build if it were about to molt, or shed its exoskeleton > (something spiders do in order to grow). > > > In mammals, the [Rabies Virus](https://en.wikipedia.org/wiki/Rabies) causes reactions such as hallucinations and sometimes aggression. Perhaps it could one day evolve to induce more and more such aggression by manipulating the chemical transfers in the brain? [Answer] Actually, it's a lot more plausible then you may think. There are some diseases that share the same way of transportation: Saliva or biting. There are also some diseases that affect humans, making their skin deteriate. So, in other words, if a zombie virus did (and they might very well) exist,they could be a type of virus or fungus (there is a type of fungus that can attach themselves to ants) that either transmits by saliva or bites. It's scary to think, but there is a very real possibility of a zombie existing. ]
[Question] [ I am designing a human society that exists in the near future. After the development of mass-produced, relatively cheap lithium-sulfur batteries (superior energy density to lithium-ion), electric vehicles- particularly aircraft- become much easier to engineer, as batteries are not nearly as heavy and can carry a longer charge. As the society exists in extremely difficult terrain, the military funds the development of low-cost, battery-powered helicopters. These two- or four-seater helicopters have decent range (350 miles or so), and are small, light, and (relatively) simple to operate and maintain, and cost less than (the modern equivalent of) $70,000 apiece. They are primarily used as a cheap and easy method of transportation or for reconnaissance, being too small for heavy weapons. They are quite common and (ideally) intuitive to fly, even to one with minimal flight experience, so much so that a streamlined mainstream model becomes quite popular with civilians living in undeveloped areas. [This article](https://www.waaytv.com/news/six-rotors-200mph-this-electric-helicopter-may-be-the-future-of-transportation/article_746d2500-b3b4-509f-8692-ee2581735fee.html#:%7E:text=With%20a%20distance%20of%20up,can%20help%20relieve%20urban%20congestion.) makes it seem like electric helicopters are potentially feasible, even with lithium-ion batteries. However, my understanding of helicopters is that they are not easy to fly and are usually quite expensive due to complex mechanics. [This helicopter](https://aerocorner.com/aircraft/robinson-r44/), which seems similar to what I'm shooting for, costs over six times what I'd like mine to. Are cheap, dime-a-dozen electric helicopters possible to manufacture? [Answer] Microlite Aircraft [![enter image description here](https://i.stack.imgur.com/qEIVi.png)](https://i.stack.imgur.com/qEIVi.png) Microlite aircrafts are the sort of things that Father and Son teams build and repair in their garage on weekends and then fly over the farmsteads of Cornwall. Weather permitting of course. Microlites are not helicopters. But it does not seem important for your question that the cheap small electric aircraft is a helicopter. Certainly a fixed wing machine is easier to fly than a spinner. The microlite uses gasoline for fuel and weighs about 100kg. For reference that's about 0.85 Dwayne Johnsons. [In the US a microlite can have a fuel tank at most 20kg big](https://en.wikipedia.org/wiki/Ultralight_aviation). The battery is about one quarter as weight-efficient as the fuel. Wikipedia says the batteries have a theoretical efficiency of about 2500 Wh/kg compared to about 12,000 for gasoline. If you replace one of the two passengers with an 80kg battey you might get the same amount of power in a one-passenger electric aircraft as a two-seater gasoline aircraft. [Answer] ## No Your battery technology only does one thing to current helicopter designs: it replaces the motor and fuel tank of today's helicopters. All other aspects of the helicopter remain the same and cost the same.1 We can [look at what helicopter engines cost today](https://www.pwc.ca/en/products-and-services/services/sales-rentals-and-exchanges/engine-sales#available-engines) and see that they're about \$375,000. The helicopter you link to in your post has a price tag of about \$450,000. That means everything else costs \$75,000, which is already more than the cost you want. The electric motor and batteries just add to that cost. And no matter how inexpensive the batteries are, the cost of the motor will always be substantial. However, how far into the future are we looking? Today's technology becomes cheaper over time, so it's not impossible, eventually. But, today... no. You'll be hard pressed to get the helicopters into the \$150k-\$250k price range. *But does any of that matter?* Today people look forward to electric vehicles with a lot of hope. So much that they don't even bother to look behind the curtain of their local electric car charging station and see the diesel generators lurking there. In short, I believe people will find your idea plausible, and therefore suspend their disbelief to continue with the story. I don't think it's worth asking whether or not what you're trying to do "can" be achieved at the cost you want. Who cares? I love the idea and hope you'll stop worrying about whether or not it's possible to really build one right now and move on with your story. --- 1 This isn't entirely true. The combustion engine and fuel tank will be heavier and take more space than the electric version will. That means the helicopter as a whole can be built smaller and more cheaply vs. its combustion counterpart while carrying the same load. However, I do not believe that will reduce the price enough to materially change my answer. [Answer] Drones/Quadcopters not Helicopters [![H](https://i.stack.imgur.com/XWr2x.jpg)](https://i.stack.imgur.com/XWr2x.jpg) They are smaller and more intuitive to fly. They can be partially or fully automated. They have fewer moving parts making them easier to maintain. A 3d carbon fibre body could be printed where the cost could be reduced to that point. If you look at electric cars, you have four electric motors, battery system, electronic control system, battery and a carbon fibre body all around that price range. If today's batteries were smaller and motors were more efficient, you could mass produce quadcopters exactly the same way. [Answer] Electric helicopters won't be cheap any time soon, even with lithium-sulfur battery technology. We've been able to build practical electric cars (at least for city use) for more than a century, but the ones with enough range and performance to get out of a city or travel between cities currently cost about twice what an economy model gasoline powered car of similar specs (passenger/load capacity, acceleration, and range) does -- and as technology is continually added, even gasoline powered cars are headed for price ranges where they won't be universally affordable. Given the much higher minimum power requirement for a helicopter to remain aloft vs. a car traveling on a highway, plus the need to lift a heavy battery, endurance and performance will tend to be poor compared to fuel powered aircraft. Current quad-copter type electric aircraft have a flight duration of less than an hour (much less, in some cases). A conventional rotor layout would help (fixed wing even more so), but even an electric version of a Cessna 152 isn't yet a practical reality. [Answer] Flocking drones. [![drone flock lifts truck](https://i.stack.imgur.com/ywMnN.png)](https://i.stack.imgur.com/ywMnN.png) <https://www.youtube.com/watch?v=hkysTzikBBU> Pretty sweet ad! Let us consider small cheap drones, because I too am small and cheap. Let us consider a 100 USD dollar civilian drone that can lift 0.5 kg. I weigh 100 kg in the buff. It will thus take 200 drones to lift me. That is 20,000 worth of drone. We will add another 100 drones because my drone harness is heavy (that is real gold) and I will want to bring snacks. 30,000. That is half of what you ask for a helicopter in (inflated future dollars!) and the flocking drones are better. 1. Redundant: if one malfunctions you don't fall from the sky. 2. Redundant: if some are in the shop you can deploy your spares and keep on flying. 3. Flexible - I might send only part of my fleet to carry my cat from place to place, or add some drones for hire when the flock carries me home from the barbeque place. 4. Cheap. We started with cheap, and small. The trick here is the flocking software. Flocking drones are not new or futuristic. [![drone swarm at olympics](https://i.stack.imgur.com/Ik9rx.png)](https://i.stack.imgur.com/Ik9rx.png) <https://dronebelow.com/2018/02/10/record-breaking-intel-drone-swarm-lights-pyeongchang-olympic-winter-games-2018/> [Answer] The main reason helicopters are expensive is safety standards (redundant systems, parts that don't have mechanical failures, all kinds of sensors for avoiding things like mid-air collisions, communication and navigation systems, etc). If you don't mind catching on fire before plummeting to your death you could probably produce small helicopters for less than $10000. For a fictional military, "cheap and unsafe" helicopters is very plausible (why spend $$ when you're probably going to be shot down anyway?). [Answer] Ignoring any issues with the lithium sulfur batteries (powerful batteries can be difficult to develop and produce, but the question seems to indicate this is a non-issue in your world), I don't see why not. A sophisticated computer system on your helicopters can make flying accessible to everyone, or even fully automatic. We have drones, and what's a helicopter if not a really big drone? Adding an advanced computer system, however, is going to drive the price up. Luckily, however, you stated that the military funds the development of these helicopters. Government subsidies can help keep the price down (if they want everyone to use these helicopters, they'll be eager to promote their usage). I'm sure there are other issues which make these helicopters less viable in our world, but none of them are major enough that you can't hand-wave them away with "computers" or "money" or something along those lines. [Answer] Yes. More specifically, a low-performing version could become substantially cheaper than today's helicopters or today's electric cars. (A low-performing, much cheaper version of electric cars should also be possible.) The technology — and hence the complexity — of electric transportation is much simpler than with combustion engines. You can get an idea if you look at the development of model drones; 40 years ago, they were basically James Bond issue, expensive cutting-edge technology unaffordable for the general public. Today you find them in blister packaging hanging by the supermarket cash register, and they run until you crash them without any maintenance. Batteries, circuits, electric motors and the plastic body are that simple and cheap. There is, however, a floor to the price of large items simply because of the amount of energy and material needed to produce them; an electric car will always cost more than an electric bike. But with cheap batteries there is no reason why a "[google bubble car](https://www.fastcompany.com/3031146/googles-self-driving-car-is-real-and-it-looks-like-a-tiny-bubble-car)" or a corresponding "bubble quadcopter" should be much more expensive than half a ton of plastic, 200 kg of Lithium and a kilometer of copper wire. Because of the mechanical and power limitations you won't be able to perform aerial acrobatics or fly races with it, but they'll get you from A to B in a rather boring fashion, just like a google bubble car. [Answer] Assuming that they are mass produced, the best option is quad copters or some type of ring around the propellers otherwise there would be a high risk flying on of these as you are not constantly looking up when flying. One wing broken means that you have to get out. There is also a potential danger when the helicopter falls to the ground. ]
[Question] [ There are a LOT of unworked holes in this, but the basic premise is my planet is a P-type orbit in a binary star system where these two stars have close orbits around each-other in order for the planet to maintain a safe, habitable distance, and it's atmosphere is purple/violet. In short, this planet is similar to Earth save for external changes. It's still habitable to humans, terrestrial, mostly water with continents and the atmosphere has nearly all the same substances. Now from my understanding and helpful comments, Earth's atmosphere is actually violet, but we can't perceive that. So I was wondering, what physical variable could possibly change that so it appears violet to the naked human eye? I ask this so I can apply the same logic to the planet I've created. I hope this makes more sense than what I've previously asked, and I apologize for being misinformed. [Answer] How purple do you want it? Daylight on any planet is the result of a 3 step process: 1. The star gives off light. 2. The light changes as it travels through the planets atmosphere. 3. The light is perceived by a creature. According to [Hyperphysics](http://hyperphysics.phy-astr.gsu.edu/hbase/wien.html), "Stars approximate blackbody radiators and their visible color depends upon the temperature of the radiator." This means there are very strict limits on what can happen in step 1. Also, I am assuming that there is nothing in step 3 you can change [i.e. the creatures on the planet are humans with normal color vision], because otherwise you enter complicated [philosophical questions](https://plato.stanford.edu/entries/color/) about what color even means. In step 2 you, as the writer, have complete freedom. You can change what the atmosphere does to be whatever you want. The catch is that the less the planet is like Earth, the less likely your readers are to accept it. So we need to get a purple sky while minimizing the change in the atmosphere. That leaves the question: how purple do you want your sky? Option 1: The first human to walk on the planet's surface says, "The sky is a little darker, just barely. Almost like a really, super light purple." Option 2: The first human to walk on the planet's surface says, "Man, that sky is $^#&ing purple. I mean kids are going to be grabbing that purple crayon so much!" Option 1: The super easy The CIE diagram shows where colors are in CIE color space, and fortunately for us, there is a curve that goes through it that corresponds to every blackbody radiator called the Black Body Locus or Plankian Locus [[image source]](https://www.researchgate.net/figure/A-view-showing-Black-body-locus-on-CIE-chromaticity-diagram-Source_fig1_304025043): [![CIE diagram with Blackbody Locus](https://i.stack.imgur.com/4Ocyo.png)](https://i.stack.imgur.com/4Ocyo.png) This curve does start to dip down toward the line of purples, which is that flat edge right on the bottom of the colored region. For step 1 simply pick a temperature for your star that corresponds to the color on this curve you want. Wikipedea currently has a [GIF](https://en.wikipedia.org/wiki/Planckian_locus#/media/File:Planck_locus.gif) showing several examples. Then have the atmosphere do very little in step 2. A close up on the Black Body Locus is available [here](https://www.waveformlighting.com/tech/what-is-the-difference-between-the-black-body-and-the-reconstituted-daylight-spectrum), and in it you can see that even Earth's atmosphere does not change the color of sunlight that much. The Daylight Locus depicts what a black body would look like after Earth's atmosphere changes it: [![Close up of Black Body and Daylight Loci](https://i.stack.imgur.com/IktGg.png)](https://i.stack.imgur.com/IktGg.png) As long as you are careful with the habitability zone of your star and the UV radiation, you can get the desired result even with an Earth-like atmosphere! Option 2: I have been working on this answer for 4 hours because of this option We are now going to have to talk about why violet is cursed and evil and makes colometry an absolutely horrible field to study. To oversimplify, a [spectral power distribution](http://hyperphysics.phy-astr.gsu.edu/hbase/vision/spd.html) is a graph showing how much light of each wavelength is produced by a light source. You can go from an SPD to any color, but not the other way around. Here are 3 hypothetical SPD and my guess as to what color they produce [It's 12:40 AM, don't judge me]: [![Some very badly drawn SPD](https://i.stack.imgur.com/Vkuxu.png)](https://i.stack.imgur.com/Vkuxu.png) If the SPD is flat with one peak, then the color will be near the curve on the CIE diagram. This is where those [charts](https://multiverse.ssl.berkeley.edu/Portals/0/Documents/FiveStarsCurriculumDocs/WavelengthsOfColors.pdf) showing what wavelength correspond to what colors come from. If the SPD is flat with one trough, then the color with be near the line of purples. If there is more than one peak or more than one trough, then there is no easy way to predict the resulting color and you need to do the [calculations](https://www.waveformlighting.com/tech/spd-to-cie-xy-calculator). The fact that purples are caused by troughs is horrible news for us because black body radiators [always](http://hyperphysics.phy-astr.gsu.edu/hbase/wien.html) look like hills, with a single peak and slopping sides. This means that your atmosphere is going to have to do a lot of work. The star would need to produce a roughly flat SPD over the visible spectrum and the atmosphere needs to absorb a absolutely ton of light across a small band of frequencies. These do exist and are called absorption bands. However, every absorption band is associated with a [specific molecule](https://www.e-education.psu.edu/meteo300/node/683), so you can't just casually make them up. This would give you a SPD like my second example, but you would have to do a lot of research to find the right chemical and a lot of world-building based on what this chemical does in the atmosphere, or your readers may not accept it. Unfortunately, we cannot take advantage of the fact that this is a binary star system to get an SPD that looks like my third example. The CIE diagram has the extremely useful property that if you pick any two points and find their midpoint, then mixing those two colors will result in the midpoint's color. This means the convex hull of the Black Body Locus is all the colors that could possibly result from combining starlight. As there are no colors there I would call purple, this super cool option that I was extremely pumped for would fail. [Answer] ## Your planet is a bit warmer than Earth Okay, so just being warmer alone will not give you a violet sky, but it does two really important things. It will increase the amount of water vapor in the air and it will make the polar regions the primary habitable zone of the world since the tropics will be too hot for any Earthlings. Here on Earth, our poles get a perpetual twilight that typically looks like this: [![enter image description here](https://i.stack.imgur.com/BZoTd.png)](https://i.stack.imgur.com/BZoTd.png) Because of how cold the air is you don't get a lot of water vapor to scatter the light, but if the poles had a temperate environment, it would look more like this for the 6 months of the year that you get sunlight: [![enter image description here](https://i.stack.imgur.com/dgDFm.jpg)](https://i.stack.imgur.com/dgDFm.jpg) Purple skies here on Earth are caused by the way light scatters when sunlight hits a sky full of water vapor and other "large" particulates (aka: clouds) in the air at an acute angle. The acute angle causes the sunlight to scatter via the [Tyndal effect](https://en.wikipedia.org/wiki/Tyndall_effect) such that the blue wavelengths are filtered out before they reach the sky overhead leaving only light in the red spectrum to illuminate you and any cloud cover. So we get red clouds and a generally pinkish ambiance. However, the sky above the clouds has smaller particulates; so, it is not effected by the Tyndal effect. Its primary mode of light refraction comes from [Rayleigh scattering](https://en.wikipedia.org/wiki/Rayleigh_scattering) which means that the sky above the clouds will appear blue. So, even though you have 1 light source, its light is being filtered differently at different layers of the atmosphere causing the light reaching you to be mostly blue and red with very little in the green range giving the sky a violet hue. Technically speaking, this world would still have generally blue/white or maybe even entirely white sky at lower latitudes, but in the regions that people could safely call home, a purple sky would be the norm. ## This could even be Humanity's actual future here on Earth If the runaway greenhouse effect goes as predicted, then we may not actually need to go to another planet for our decedents to eventually experience this. As global temperatures rise from greenhouse emissions, an increase in atmospheric water vapor will go hand in hand with the increase in atmospheric CO2. The poles of Earth will become increasingly humid while the tropics become barren wastelands. Eventually more humans may live under a violet sky than a blue one as we flee to the only remaining habitable parts of the planet. [Answer] Violet filter [![violet fileter](https://i.stack.imgur.com/Do8qPm.png)](https://i.stack.imgur.com/Do8qPm.png) <https://lensesforsnap.com/purple-snapchat-lens-filter/> The problem is that those pesky other colors clamor for our attention so we cannot appreciate the violetness. Violetiosity, as it were. So: filter those other chumps out and let only the violet thru! One could filter out all frequencies except a single frequency - things would look dark and monochromatic but the sweetest chromatic of violet. Or you could let some of those other colors in but just a little, limiting their roles to the backup dancers of the lit world. And fully allow all that could be Violet! Snapchat does this thru some digital jiggery-pokery. I propose instead sweet shades of violet hue. [Answer] There are a few things that make the sky look blue, but it all really comes down to the amount of red and green overwhelming the blue end of things. There are two ways to shift this. The simplest would be to increase the number of blue cones in the eye. If these aren't Earthlings, you can do whatever you want with the colors. If they are Earthlings, then you need something that will block/reflect the red end of the spectrum before Reyleigh scattering takes effect. Alternately, you could have a chemical in the upper atmosphere that flouresces in the purple spectrum. How that chemical got there is a matter of story telling. [Answer] Evolution is the answer. We don't perceive ultraviolet very well because of evolution. There are white (at least to our puny violet sensing eyes) flowers. Bees love them. They think that these plain, boring white flowers are awesome. Because they can see how amazingly purple they actually are. The flowers are colored in ultraviolet! The flowers evolved so that bees could spot them. And bees evolved so that they could see them. Dogs, on the other hand, are infamously colorblind, they can't see green and red, rather they show up this weird yellowy blue color for them. We know this because, they don't have the right types of cones in their eyes to perceive these colors. So, a couple of ideas. You have your humans face some sort of evolutionary pressure to develop a new type of cone in their eye that let's them perceive ultraviolet light. Or if technology is advanced enough and there is some reason to install ultraviolet sensors in their eyes that interface with their brain, essentially, artificial cones. Since your question involved, the "naked human eye", we'll eliminate artificial cones. That leaves evolutionary pressure to develop those new cones. A good evolutionary pressure is a predator. This new world, perhaps, has an ultraviolet-colored predator that killed a bunch of humans. Slowly, the human colonists evolved to be able to better perceive the threat. And now, bingo, they can see beautiful purples. Potentially, these colonist humans could visit earth and be shocked that earth skies looked purple too, while all the earthlings insisted that the skies are blue. [Answer] Ordinary human seeing purple: To have an ordinary human magically teleported there and seeing purple sky, you mainly want to block a lot of green light from a sun-like star. You can push temperature higher to get bluer sun, it will be helpful to get deeper purple without blocking most of the light, but merely raising temperature never gets to purple - it remains stuck in blue. So, what would absorb all that green? The easiest solution is to have a simple chemical that has correct absorption bands (you can handwave that part, there are bound to be many). Another, more complex and less plausible (but IMO more "alien" and possibly fitting) option - airborne photosynthesizing bacteria. Perhaps because the world has ever-present wind, one bacteria opted to leave confines of sea or ground, which offered a huge evolutionary advantage in amount of light the bacteria can gather. The problem here is that you want the bacteria to absorb green and pass most of blue and red (instead of reflecting green and absorbing blue and red like ours). Absorbing green to make energy is easy enough to handwave/ignore, passing a significant fraction of red is fine, but passing blue is tricky. So, another inspiration from nature - photonic structures eg morpho butterfly are used to reflect blue and prevent damage to the delicate internal organs (if you can call them that in bacteria). A humanoid seeing purple: To have a non-human seeing purple, you simply state they see blue and purple much better than we do, there is no need to explain further. We evolved from primates seeing 2 colors - blue and yellow. Then yellow receptors split to green and red. It wouldn't be a huge stretch of imagination to have evolutionary advantage of having blue split in the far future, like the yellow did in the past. There are many animals seeing in UV as well, such as bees, shrimp, birds, fish. As well as many animals seeing worse than we do, eg most mammals and fish. ]
[Question] [ Vaughn Heppner wrote a [science fiction series](https://rads.stackoverflow.com/amzn/click/com/B074CF62CP) in which humans have to defend against a growing cyborg threat. The star of the series, Martin Kluge, comes up with a way to destroy a group of military spacecraft by sending a high speed cloud of sand into the ships. Traveling at significant speeds, each mote of dust blasts a huge hole into the oncoming ships, effectively winning the battle. What are some methods of defending against this weapon? Detonating nuclear blasts wouldn't have any effect since there is no blast wave, right? I can imagine high speed focused lasers, but it would take an enormous amount of power to actually destroy something with a laser - albeit at the zetajillion times you'd have to do it against a large sand cloud. Any other theories out there that are (somewhat) scientifically feasible? This was originally posted in sci-fi, but they suggested that it might be better suited for this forum. Assume that each particle of dust varies between 1µm - 100mm, the cloud measures 20 x 20 x 20 km in size, and the particles are traveling at 30 km/s. The density of the dust cloud is 0.125 g / cubic meter. [Answer] > > the cloud measures 20 x 20 x 20 km in size, and the particles are traveling at 30 km/s. The density of the dust cloud is 0.125 g / cubic meter. > > > That's about a million tonnes of debris there, with a total kinetic energy of 450PJ (about 100 megatonnes TNT equivalent, more or less). Each square metre of the front of the dust cloud has 2.5kg of dust behind it, giving a yield of ~1.125GJ/m2... that's about a quarter of a tonne of TNT equivalent. A ship with a 400m2 cross-section would be hit with the equivalent of a hundred tonnes of TNT, pasted all over its nose. I'm not going to say that's not very much, but it is a fairly small proportion of the energy of the cloud. Ships are not going to be within 20km of each other, so that's a fair amount of overkill to throw at one ship, especially given that a) the acceleration mechanism is going to be very energetic (and therefore visible from far away), the cloud is going to occlude things behind it (and therefore be visible from far away) and is going relatively slowly compared to the vastness of space and so the target ship is going to have plenty of time to see it coming, and will not have to manoeuvre very hard to evade it. > > What are some methods of defending against this weapon? > > > Given that its only working out as 2.5kg of mass per square metre of cross-sectional area of the ship, simple dumb armoring will be pretty effective. A sheet of aluminium 1m x 1m x 1mm weighs a little more than that, and might be reasonably expected to absorb a decent amount of the impact. A multilayer [Whipple shield](https://en.wikipedia.org/wiki/Whipple_shield) made of successive thin layers of suitable materials will protect the ship behind it quite effectively, and without an unreasonable mass penalty. Obviously, this only works a limited number of times, but given the difficulty of generating the dust cloud in the first place and the good chance of the target seeing it and evading it, the shooter might not be able to hit the target enough times to take it out. > > Detonating nuclear blasts wouldn't have any effect since there is no blast wave, right? > > > Well. A nuclear blast in space does generate a lot of radiation, and as MadScientist already observed you might reasonably expect the dust cloud to absorb a reasonable amount of that radiation which will vaporise some of it and deflect some of it. Remember the whole cloud doesn't have to be disrupted, only enough to limit the amount that hits the Whipple shielding (or other armor) that the target spacecraft has. If you hit the cloud far enough away, the deflected dust grains (and the gas expanding from the vaporised grains) will act like a blast wave and disrupt the cloud further. However. Not all nukes are created equal! Behold the [Casaba Howitzer](https://en.wikipedia.org/wiki/Casaba-Howitzer), or even its non-militarized cousin the [Orion drive](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)) pulse unit. These act as directional nuclear blasts in space, absorbing a substantial portion of the radiation emitted by the blast into a propellant disk which is turned into a dense plasma cloud that flies towards the target. This is very much the sort of blast that can disrupt the gas cloud, to the point where I feel that this might be the ideal defensive option. Note that Orion propulsion units are potentially non-military devices (they may be nuclear warheads, but they're far from optimised to be weapons) and so could be used in defence by non-warships. > > I can imagine high speed focused lasers, but it would take an enormous amount of power to actually destroy something with a laser - albeit at the zetajillion times you'd have to do it against a large sand cloud. > > > As with the nuclear radiation pulse above, you don't have to completely destroy a dust grain to reduce or eliminate its damaging capability. The dust cloud is optically thick, so a laser weapon might reasonably expect a large proportion of the energy of the beam to be absorbed. Some of the grains may be wholly vaporized, some will be partially vaporized which will deflect them, and for others it may be that the [radiation pressure](https://en.wikipedia.org/wiki/Radiation_pressure) of the beam can provide a useful amount of deflection or slowing-down. Remember that deflected (or slowed) grains can collide with other parts of the cloud, further disrupting it. You're only limited by the cycle time of the laser, and the distance at which you can detect the dust cloud (which is likely to be far away). I'd much prefer the Casaba Howitzer to a laser, though. You might also be able to use [laser driven lightsails](https://en.wikipedia.org/wiki/Solar_sail)... a series of featherweight sheets blown forwards by light pressure alone, but it seems difficult to get enough mass moving quickly enough to make a difference. A [magnetic sail](https://en.wikipedia.org/wiki/Magnetic_sail) driven by a particle beam might be more effective, both in term of delivering mass and getting projectiles launched and accelerated quickly. By way of a bonus, these things might reasonably be carried for non-military purposes, which might be plot-relevant. > > What are some methods of defending against this weapon? > > > Why not fight fire with fire? Generate your own high-speed clouds-o-doom, and fly behind them, relying on them to help sweep opposing clouds, drones, missiles and ships out of the way. Obviously you can't easily carry a million tonnes of grit around with you everywhere, but you should be able to do it at least once. --- Honestly though, I'm not sure that this is a very useful weapon. It is difficult to produce, not practically portable, and is too easy to spot at extreme ranges and avoid. It also appears to be possible to defend against without undue difficulty. Send your weapons engineers back to the drawing board. [Answer] ### Whatever the ship already uses to protect from interstellar dust A dust particle hitting the ship at 30 km/s is no different from a ship travelling at those speeds hitting a stationary dust particle; which ships would already routinely do on their travels. It is true that this cloud would be far denser than the interplanetary or interstellar medium, but each particle and impact is still discrete; a ship that can tank a million particle impacts over the course of its travels before it needs a hull replacement, is probably a ship that can tank a million of those impacts in a second. It is true that many successive impacts would heat up the hull and weaken it for the next impact, but also consider the fact that 30 km/s is a very slow speed for a sci-fi spaceship; that's slower than some of our real-life solar probes, and sets a travel time of years just between planets in the same system. A faster space-ship, particularly one that goes faster than light, would need some defense against particles far, far more energetic than anything this weapon can muster. What defense do ships use against space dust? For a very "hard" sci-fi answer, consider using the beryllium disc which was thought up in the 70's for [Project Daedalus](https://en.wikipedia.org/wiki/Project_Daedalus). This is an erosion shield; it is meant to ablate over the course of the journey. An omnidirectional equivalent would be a thicker hull that needs replacement after battle. Other ideas include strong magnetic fields ([anything is magnetic if you try hard enough](https://en.wikipedia.org/wiki/Magnetic_levitation#Diamagnetic_levitation)), or the warping of spacetime itself. Basically whatever FTL mechanism you have, it should have dust protection built into it. [Answer] Small size means that strong flow is relatively effective at blowing the grains off course, or even stopping them. Spacecraft have rockets. A rocket should be able to blow the sand away. However ... * The exhaust plume of the rocket plume will be far smaller than the cross section of a large spaceship, for grain clearing duty you would probably change the nozzle geometry to create a wider exhaust plume at lower velocity. Probably need to sweep an area with gimbaled rockets * This also means that a craft in "defensive mode" needs to have it's main rockets pointed at the dust cloud, limiting it's maneuver options * The exhaust of the rocket dissipates, so the effect will be short range - possibly a few hundred meters * This will burn huge amounts of fuel. The main offensive use of dust: To force opposing craft into spending valuable fuel on "grain blowing" As for detection of the dust, I'd assume IR or active laser scanning of suspect areas. Not sure how good we are at detecting dust clouds in near space. [Answer] I would not be so quick to dismiss good old fashioned nuclear weapons. It's true that there is no blast wave for a nuclear detonation in a vacuum. Most of the energy is output in the form of a staggeringly intense flash of soft X-rays. As a very rough order of magnitude calculation, the average nuclear weapon X-ray photon energy is around 12Kev, which corresponds to an attenuation coefficient of about 100 microns. This is well within the bounds of the grain size specified, meaning a reasonable percentage of the X rays that pass through the sand will be absorbed by the grains. This will apply radiation pressure on the grains, and may even be enough to partially vaporise the sand grains, causing an ablation-recoil away from the blast. It seems plausible that a sequence of powerful detonations leading into the cloud would blow out a "bubble" in it. If correctly timed, this may allow a defender to punch a hole in the cloud that they could dodge through. I make no guarantees as to the efficiency or number of weapons required. I would happily defer to anyone actually willing to run the numbers, but that is a non-trivial exercise. [Answer] # Some old shower curtains (or any other thin, flat, cheap material you have on hand) The toughest part of defense here is knowing the attack is coming. I take that as part of the premise of the question. Perhaps there is a cloud of tiny drones surrounding your fleet in all directions to relay a warning. Now if we know the attack is coming, and from where, we don't need to block the entire 20 x 20 km "attack formation" of sand grains. We only need to block a ship-sized area of it. So if we can jettison an opened bale of old shower curtains that were on board, and maneuver the ship(s) some kilometers directly behind them, the sand grains will ravage that bale of curtains, and send dangerous soft plastic shrapnel in all directions ... but barely any of the sand or plastic will actually hit your flagship. And all the other ships are stacked up at odd intervals behind it, safely in its "shadow". If you are short on shipboard luxuries (or hygiene), you could press a solar sail into use for this purpose. Hopefully you packed a spare in case something went wrong with it ... right? [Answer] 30km/s is not much in space (voyager is travelling faster than 17km/s). Your visibility is millions of km in space. Blasting sand too late means sand blasters will be in effective weapon range before fired, risking getting attacked. Thus, simply dodge the incoming blast. If they wait until you get close enough so you cannot dodge, take out the blasters before they fire. As long as you know they are going to do this attack, it won't be effective. If you don't know about it, then you are in trouble. If you want it to be more challenging increase the speed to a few % of the speed of the light. Now it will travel a million km in a few minutes and then the attackers will be scrambling to defend themselves using interesting tactics. [Answer] Ionize the dust? Depending on available power, and no hard science tag content here. you could using an ion beam ionize the dust field and generate a powerful magnetic field around the ship to divert the dust around your ship. In effect a reverse [Bussard ramjet](https://en.wikipedia.org/wiki/Bussard_ramjet). One could imagine (sculpting) configuring the magnetic fields in a way that the force lines would efficiently divert the particles taking into account the overall shape of the space craft. I cant math that well, but for my own curiosity, I would like to see how much energy over a given time it would take to divert the kinetic energy of the sand cloud around the spacecraft. EDIT Bonus, depending on your universe tech etc. Devices like this or something to modify from could be in place on your ships already to protect from solar radiation / flares / space herpies of any sort. [Answer] > > Detonating nuclear blasts wouldn't have any effect since there is no blast wave, right? > > > You may have heard of Project Orion, that designed spaceships that would use the blast from atomic explosions to push on a pusher plate that would transfer momentum to the ship. And the plan was to use the blast from the atomic explosions to not only launch the spaceship from Earth with its dense atmosphere but also to launch the spaceship from airless moons and planets and to propel the spaceship through the vacuum of space. But how can atomic explosions create a blast in the vacuum of space where there is no air to be blasted against the pusher plate of the spaceship? The explosive devices would have to provide their own "air", actually solid material on the outside, arranged on the side facing the pusher plate so that the vaporized mass would be hurled against the pusher plate to propel the ship. And similar designs of explosive devices could be used to vaporize material and fling it against the approaching clouds of dust. the missile swould be launched from the defending space ship, and thus would have its velocity, before being fired toward the cloud of space dust, thus increasing their velocity toward the cloud of space dust. And when the bombs exploded behind the stored particles of matter, the bombs would add considerable velocity to thevaporized matter, so that it would be approaching the dust at several times the speed of the dust. So when dust particles were struck by gas particles from the bombs in the missiles, the dust particles would slow, and stop, and then be pushed backwards, away from the incoming space warships. I don't know how well such a system would work, but someone interested could check the math to see how well it might work. [Answer] Use blocks of ice that are formed into a shield. Yes, this likely requires being able to resupply from a planet afterwards, but there's also plenty of [ice in space](https://mobile.arc.nasa.gov/public/iexplore/missions/pages/yss/april2012.html), too. I was going to suggest spraying water to form a wall of water ahead of the spaceship, but that has [problems](https://physics.stackexchange.com/questions/98666/water-in-vacuum-or-space-and-temperature-in-space) of vaporizing and reduced density. There's plenty of ice in the form of comets, asteroids, and various other space debris. Just pick (or make) a suitably sized shield and push it where you want to go. The sand will either wear away only the ice, bounce off, or stick to the ice and make a better shield. If you want something of specific size, you can have the ship manufacture or otherwise shape the shield by harvesting water or ice from a planet or that space debris, forming it inside the ship, letting it freeze under pressure (to avoid vaporization and loss mentioned earlier), and moving it to the front of the ship. An ice shield is nothing new in science fiction, so you shouldn't have to justify it. ]
[Question] [ So, we know that big creatures will generate lots of heat if they’re active. We also know that wings are very good at venting excess heat. Now for most animals, this heat isn’t exactly spectacular, a few degrees here or there. Of course, if an animal generated more heat because it was really, really big, the effect might be a little more exciting. So let’s take a big creature that generates lots of heat. Let’s put big wings on this creature that vent the excess heat, and let’s say that this creature can control how the heat is vented from its wings. The creature vents the heat to the underside of its massive wings, creating large pockets of very hot air. Then, upon encountering something that the creature doesn’t like, it flaps its gargantuan wings and generates a hurricane force blast of scalding hot air. So the question here is how much heat, and how much wind? For the purposes of this question, we’ll go big. Let’s say a 2-mile wingspan, each wing from 1/4 to 1 mile in breadth (base to tip), on a creature that is 2 miles long, with the heat generation you would expect from an active animal that size. If you can answer for both raptor-like wings and bat-like wings that would be great. For the purposes of this question ignore things like “how could this creature move” or “how could the wings withstand the force of being flapped” as those are different questions entirely. Here’s a link to my other related questions [1](http://worldbuilding.stackexchange.com/questions/137872/the-nuclear-dragon): <http://worldbuilding.stackexchange.com/questions/137872/the-nuclear-dragon> [Answer] A one mile long wing is big, I mean, REALLY big. Let's say the "offensive wing beat" starts with the wing pointing backwards and completes 180 degress later pointing forwards. The wing tip completes a full half circle with a one mile radius, so basically 3.14 miles. How long does a beat take? 1 minute? 1 second? 10 seconds? Lets go with 10 seconds. The wing tip will travel 3.14 miles in 10 seconds, or 1,884 miles per hour. The speed of sound - at sea level - is approx 770 miles per hour, so the wing tip is traveling at something like mach 2.5 during its rotation. So for each beat the wings are displacing a couple of cubic miles of air in those 10 seconds, I'm guessing there'll be a massive pressure wave similar to a nuclear blast traveling forwards from your mega bird. The secondary blast is from the air rushing in to replace that moved by the wing beat, dragging debris with it. I don't have enough physics to workout the actual forces involved, but the stored heat under the wings is the least of your worries. [Answer] ## Edit jdunlop has repeatedly pointed out the flaws of my answer so even if you have read the answer please reread it because there have been a few significant changes made. (in the Energy real world comparison part and following, it's a more accurate formula) This simply is an expansion to Binary Worriers answer. (Math to display the true scale) This is not that accurate because there are a lot of assumptions but it is good to display the ballpark in which the forces are working. ## Values: * 1 mile (1,609.34 m) long wings * 10 seconds to move 3.14 miles (ca. 5,053 m) * we assume a 2:1 ratio in length to width so 0.5 miles (804.67 m) for our wing width * this gets us a surface area of 1294987.62 $m^2$ or 0.5 $miles^2$ * A sphere of 1 mile (1,609.34 m) has a volume of 1.746 $\cdot 10^{10}m^3$ or 4.189 $miles^3$ * But our wing only has $\frac {1}{4}$ of the diameter the volume drops accordingly to 4 364 877 255 $m^3$ or 1.05 $miles^3$ * Lets reduce this by another 20% to adjust for imperfections of the wings and no full 180° flap of the wings (also wings don't tend to be perfectly shaped like the upper part of a circle). Which gives us 3 291 901 804 $m^3$ or 0.84 $miles^3$ * Finally we need the [weight of air](https://www.wolframalpha.com/input/?i=air) which is 1.275 kg per $m^3$ ## Math As Binary Worrier already explained the speed of each wing must be 1884 mph (3,032 km/h) to keep the numbers from exploding to astronomical scale we will assume that the wings already have this speed when starting to flap. Weight First we need the weight of the air which is our volume times the weight we already established. $1.275 kg \cdot 3291901804 m^3 = 4,452,174,800 kg$ [This is 8.90435 TIMES THE WEIGHT OF THE BURJI KHALIFA](http://blogs.discovermagazine.com/80beats/2010/01/04/10-things-you-didnt-know-about-the-burj-khalifa-the-new-tallest-building-in-the-world/). (The tallest building in the world currently) Force To get the force we use this trusty formula: $F = m \cdot a;$ F = force, m = mass, a = acceleration. Our acceleration is the speed of the wings divided by 10 (it takes 10 seconds for the wings to hit every air molecule in our designated volume) so 303.2 $km/h^2$ or 84.22222222 $\frac {m}{s^2}$. So when plugged into our formula it looks like this: $F = 4452174800 kg \cdot 84.22222 \frac {m}{s^2} = 3.75 \cdot 10^{11} N$ (N = Newton) Energy/Real world comparison (redone) Energy is $E = 0.5 \cdot m \cdot v^2$ E = Energy, m = Mass, v = speed. Plugging our values in: $E = 0.5 \cdot 4452174800 kg \cdot 842.22222222^2 \frac{m}{s} = 1.579 \cdot 10^{15}j$ Which is about $3 \cdot 10^{14}j$ less but still enough [to supply the world in 2015 for 6 days](https://en.wikipedia.org/wiki/World_energy_consumption#Overview). Or 6 times less than [a standard hurricane releases per second](https://science.howstuffworks.com/environmental/energy/energy-hurricane-volcano-earthquake1.htm). Edit V.2 For the creature unleashing the attack with the rough approximation for the weight by [jdunlop](https://worldbuilding.stackexchange.com/questions/137891/superheated-wing-blast/137908?noredirect=1#comment429567_137908) we can estimate the creatures speed by the same formula we used above: $E = 0.5 \cdot m \cdot v^2$ this time we have to rearange it to get the speed: $v^2 = \frac {E}{0.5 \cdot m}$ again with our numbers: $v^2 = \frac {1.579 \cdot 10^{15}j}{0.5 \cdot 20 \cdot 10^9 kg} = 157904.9$ because v is squared we have to take the root and get: 397.37 m/s or 1430.54 km/h or 894.01 mph. Conclusion (corrected weight comparison) Anything that faces this creature has far greater problems than the heat released by this creature. The much bigger problem for the attacked creature is if it doesn't weigh more than 25 311 cars (each 1000 kg or 1 metric ton) it will leave an earth like planet for ever because it will reach escape velocity. And even when both (the attacked and the attacker) weigh more these creatures have to somehow not hit the ground, mountain, or hill with supersonic speed. Additional Info For the weight in cars needed not to leave the planet I used the formula from above and re arranged it this way: $m = \frac {E}{0.5 \cdot v^2}$ for the escape velocity [is 11170 m/s](https://en.wikipedia.org/wiki/Escape_velocity#Multiple_bodies). Couldn't use my physics book to site it but used its value instead of Wikipedia's the values are close enough though. So with the values: $m = \frac {1.579 \cdot 10^{15}j}{0.5 \cdot 11170^2m/s} = 25310794 kg$ or 25 310.794 metric tons. [Answer] I agree with Binary Worrier's analysis, however: assuming this critter is in fact your 2-mile long nuclear dragon from an earlier question, the generation of massive amounts of heat under the wing surface helps answer the "how the hell does it FLY??" question very nicely - lift generation in a typical wing is driven by pressure differential between the lower straighter surface and the upper more curved surface of a wing (the air moves faster over the curved section and as a result, the 90 pressure against the wing itself is lessened, this more pressure beneath the wing) and secondarily through angle of attack dynamics, and in highly mobile wings on certain birds, root twist and other considerations. Your Nuke-dragon's excess heat radiators, in heating up the atmosphere beneath them, generate lift automagically, as the hotter gas expands it exerts more pressure on nearby surfaces. Of course, the critter would need to cup the wings deeply to prevent escape of the heated gas... so the "flight" would be more like free ballooning - perhaps it's but one trick in the critter's flight methods - a way to do an equivalent to raising on thermals as hawks do absent an external thermal gradient - then your beastie closes wings behind and dives... ]
[Question] [ # Introduction See background information [here](https://worldbuilding.stackexchange.com/questions/100613/can-you-design-your-own-plants-without-a-computer). In the Harmonious Republic of Mars, the finest forms may be found of any and all luxuries available in the Solar system. This includes moving pictures. Only in the Harmonious Republic does mankind watch, rather than read, the news. And in color! With blasphemous computers banned for all time, these television devices were thought to be relegated to the history books. But through decades of dedicated work in the Bureau of Public Entertainment, a new style of moving picture screen was developed, so that in all public spaces a person might be able to follow the pronouncements of the Supreme Council of Harmony or any other part of the Harmonious Bureaucracy. For those honored to be members of the Harmonious Cohort, a moving picture screen in the home is even possible. Indeed, life is good here on the Red Planet. # Question The [GE Porta-Color](https://en.wikipedia.org/wiki/Porta-Color) is the last all CRT color television made in the US. Given that computers are banned, and given all current and plausible near-future technology, what advances could be made over the Porta-Color? How high of a definition could TV screens in public places (not necessarily affordable for a private home) have? ### Considerations * Computers are banned. Thinking about a computer will get you burned at the stake. Therefore, people don't think about making computers. * For the purposes of the question, anything that has electronic memory is a computer. Anything that has software that can be programmed is a computer. Anything that was ever historically considered to be an electronic computer is a computer. * An electric calculator has electronic memory and is a computer. Slide rules and nomographs are examples of mechanical 'computers' that have no memory other than their current state; they are not computers. * The GE Porta-Color is not programmable and has no memory, therefore it is not a computer. Any [ASIC](https://en.wikipedia.org/wiki/Application-specific_integrated_circuit) that can be cost effectively designed entirely by hand (and doesn't have any memory, and is not programmable) is not a computer. * Transistors, and thus LEDs, are not banned. Whether you could develop LEDs without betting burned at the stake is another matter. * All materials available at the present day will be available in the Harmonious Republic, unless those materials cannot be created without a computer. * Plausible near-future technology means something where most of the engineering problems have been solved and the only remaining obstacles are refinement or cost or culture. * For example, universal [smart glasses](https://en.wikipedia.org/wiki/Smartglasses) are plausible near-future technology, fusion power is not. Self-driving cars would be plausible too, except those would definitely get you burned at the stake. [Answer] News Reels Film, the original analog video material, far exceeds any modern HD standard. 35mm film was the standard for movie theaters from the 1920's until recently when digital projectors became common, and a 35mm negative is estimated to be around 87 megapixels, or over 10x 4K resolution. IMAX 70mm film would have over 720 megapixels. With fast transit, half the circumference of earth with no oceans, film reels could be delivered to the opposite end of Mars in 12 hours if carried at 500 mph. So, news is filmed in the morning, duplicated, then shipped across the planet by evening. Small projectors could be used in homes, large projectors could be used in theaters or public displays. [Answer] There really isn't a limit, other than some mild limits for synchronization. "High definition" in public places, where there's few size limitations, "high definition" is more marketing speak than anything. The trick is to build a composite screen out of many smaller screens. This is how all big screens are manufactured. Instead of trying to make some extremely powerful CRT with 40k lines (well, 20k interlaced, of course), you make a huge display that is 80 screens tall, each one with 500 lines, which was doable in the pre-computer era. [![Many-screens together](https://i.stack.imgur.com/TAop8.jpg)](https://i.stack.imgur.com/TAop8.jpg) As for what advances could be made, a serious question would be what advances are needed? Size and weight were the main limiting factors for a CRT. Kingledion provides [an answer](https://worldbuilding.stackexchange.com/a/101529/2252) which suggest that plasma screens could be possible to deal with these issues. But the real question is "what advances are the members of the Harmonious Republic interested in?" That is likely not the same thing we will be interested in. With computers, we can always take the "more is better" approach, but that is not as popular without computers to sort the data for us. I would presume that they would not be impressed by a 16MP camera on a cell phone, just because it has a higher number of pixels than the 2MP camera they have already. With the name "Harmonious Republic," they might want to give some lip service to the concept of "harmony." I think they might be interested in having screens that adjust their color balance and brightness to blend in with the environment a bit more. Advanced glass blowing might let them design TVs that work around unusual shapes rather than having to make everything square. But that's just me. [Answer] With analogue TV, there are no hard limits. CRT's have no inherent horizontal resolution, the limit is the size of phosphorus atoms and the colimation of the beam, and the quality of picture is given by frequency bandwidth of the signal (this is valid for B&W TV, colo(u)r introduces complications in the form of a discrete mask). Vertical resolution equals the number of lines, and that is limited by bandwidth. [French 819 line](https://fr.wikipedia.org/wiki/819_lignes) (737 lines visible) standard had a bandwidth of 14 MHZ (in VHF band no less), and that is 1940s technology - no computers necessary at all. Japan's [MUSE](https://en.wikipedia.org/wiki/Multiple_sub-Nyquist_sampling_encoding) had 1125 lines (1035 visible) took 20 MHz, with some tricks squeezed to 8 MHz channel. European [HD-MAC](https://en.wikipedia.org/wiki/HD-MAC) was similar - and that's early 1980s technology. (note that all of these are interlaced standards) If you move to gigahertz frequencies, you have enough bandwidth for many multiplies of this - and that's still analogue, no computers nor even [DSP](https://en.wikipedia.org/wiki/Digital_signal_processor) needed. However, you soon run into problems with designing gigahertz circuits and producing your TV sets in sufficient quality and tolerances without computers in the design and production lines. This might be of no issue if the components or the whole TV sets are imported. [Answer] This is an answer to [Revision 3](https://worldbuilding.stackexchange.com/revisions/101519/3) of the question, please judge accordingly. --- # No limit Given your restriction: > > Computers are banned. Thinking about a computer will get you burned at the stake. Anything that approaches Turning complete, other than a human brain, is considered a computer. > > > and given that OpenGL shaders (model 1 and 2) was never even close to being Turing complete, you are good to go. Later models were closer to Turing completeness because games required it. No need for arbitrary iteration processing when all you want is video codec. Similarly, UDP-like networking does not need loops, and can be easily implemented in a non-complete way. For media stream, some dropped frames are no concern. That said: your video can be as high definition as you like it, using high-tech electronic than in terms of performance does not need to be any weaker than modern tech, and can indeed be designed in a turing-incomplete way. --- GPIB bus didn't require turing-complete computer hardware. It worked fine for scientific electronics significantly more limited. Similarly, scientific calculators with graphic display was not fully programmable, but could be nearly as powerful as computers of their time (nearly because there was no need for more). Advanced electronic could be developed in parallel with computers without being computers. We stopped advancements only because computers were cheaper. [Answer] # Plasma screens are possible The technology underpinning plasma display has little to do with the motive force behind it. In a cathode ray tube (CRT) television, an electron gun scans across the phosphorescent screen in a raster pattern. There are three electron beams, one for each color red, green and blue. For a plasma display, the same setup could be used except that instead of three beams illuminating the phosphorescent screen of a CRT, the electron gun would activate invividual plasma cells. These cells are basically tiny fluorescent lights, with gasses and interior coating designed to emit the three primary colors. Going with this design will save power by reducing the number of electron guns, remove the CRT will allows better scaling to larger sizes. It will [also allow](https://en.wikipedia.org/wiki/Comparison_of_CRT,_LCD,_and_plasma) much higher contrast ratios. Where CRT pictures are limited by the activation of the phosphorous screen, the individual plasma cells can activate and shut off more quickly, giving better response times and higher possible frame rate. With the same circuitry demodulating whatever the desired picture signal is, a plasma display will allow better picture quality. [Answer] # You forgot about the 1080i CRT analog TVs from Japan! [![enter image description here](https://i.stack.imgur.com/x7pKr.jpg)](https://i.stack.imgur.com/x7pKr.jpg) > > "Japan had the earliest working HDTV system, with design efforts going > back to 1979." > > > Silly Americans ;) They can easily get up to 1080i. For the following example I checked the manual and all the inputs are analog. Sure there's some computer stuff in it like all TVs have but if you're asking "can you make a high def CRT TV" The answer is YES! Japan had been broadcasting analog HD signal for a long time at 1035i. [Source](https://en.wikipedia.org/wiki/Analog_high-definition_television_system) PS: [Lets also talk about projection TVs for a moment.](https://www.cnet.com/products/toshiba-theaterwide-hd-50h12-50-rear-projection-tv/specs/) Because, there's no need to limit yourself to CRTs. [![enter image description here](https://i.stack.imgur.com/gEINH.jpg)](https://i.stack.imgur.com/gEINH.jpg) [(Source) How is this BestBuy link not dead yet](https://www.bestbuy.com/site/mitsubishi-65-widescreen-hd-ready-rear-projection-tv/6388553.p?skuId=6388553) [(Source)](https://www.crutchfield.com/S-nMWVqbX6Eys/p_15840XB700/Sony-KV-40XBR700.html) [(Source)](https://www.youtube.com/watch?v=4euXYR-fkB0) PPS: I imagine that if CRTs were not abandoned, some day they could get them up to 4k. I'm not knowledgeable enough to say that. Someone please correct me in the comments. [Answer] Display isn't computing, so Mars' laws can be dismissed as irrelevant. Individual policemen may argue that anything at all is a computer, but if it's the government putting these things in place, then the law matters, and those policemen's opinion does not. So on the face of it, the question can be simplified to one of various questions about electronics, suitable for electronics.se rather than worldbuilding.se. 1) If the question can be reduced to "what're CRT's resolution/size limits?" then the ViewSonic P225f was 2048x1536. Some online sources claim 2560x1920, but I suspect this was processing resolution, not display resolution. [Aside: while max display resolution and max processing resolution do not always match up, it is important to blithely ignore any people who claim that color CRTs lack an inherent native resolution, or in any way lack pixels. They are either confusing them with analog monochrome CRTs, are unaware of how the technology worked, or are using their own incorrectly nitpicky definitions of jargon terms like 'pixel' in order to try to be argumentative or look smart.] CRTs, because of the glass used around the sides of the tube, inherently mean big gaps in video walls, so you're limited by the max size of one "screen". These gaps can be ameliorated entirely with projection and compensation (at the cost of brightness), or with lenses (assuming the viewing angle is correct). 2) Perhaps instead the question can be reduced to "what're the resolution/size limits of non-digital displays?" After all, restricting to CRT makes little sense in terms of "computing". LCD, LED, etc are also non-computing, and can at least in theory make a video wall with no (or, negligible) gaps. A couple of mm at most. <http://en.wikipedia.org/wiki/Analog_television> may be a helpful resource: analog transmission and processing is limited mainly by bandwidth. Transmitting the signal over cable can entirely remove that limit, meaning that with enough cables, you could have an entire IMAX sized wall displaying video at 0.2mm dot pitch. That would be a fairly epic challenge, though. First, you'd need a camera that could capture it... but IMAX has shown this is possible on celluloud, which is analog. Then you'd need to split each celluloid image up into signals for many "little" screens, and transmit the signal for each mini-screen on the wall. 3) But I think what the question actually meant "what're the resolution/size limits of displays that use no integrated circuits" particularly given the example given: the Portacolor was US' last valve TV produced, not the last CRT TV. However, this still reduces to one of the two earlier options, as valves became redundant only due to their size, power requirements, cooling requirements, cost, unreliability, and other flaws. Their switching speed and other capabilities were never the issue, and were improving as constantly as ICs have. Moore's law was invented before Integrated Circuits. --- But this is Worldbuilding.se. So we have Worldbuilding concerns. So this IS a Worldbuilding question. So perhaps instead the question can become: "are there things that would decide one way or the other between those two options? That could either permit or forbid LEDs (diodes are semiconductors), LCDs, and plasma screens?" That depends on the terms of the law, and that falls very firmly into the realm of Worldbuilding. Say the law came about because an Artificial General Intelligence nearly wiped out humanity, causing everyone to have to flee to Mars. So, obviously, the police and public will understand the law as "no computers", since that's the easiest way to explain it to laymen, but what actually is forbidden is some blahblah legalese fine print that prevents AGI from being redeveloped. In that case, the law may be written to prevent use of semiconductors, which would prevent any realistic kind of AGI-capable computer. This would also prevent LEDs and OLEDs, but permit plasma and LCD. Or it could be written about the processes used to create them: no photolithography, perhaps. This would make any of these technologies difficult or just completely impossible, other than the CRT. Or it could be written to prevent digital electronics - again, this would limit things pretty much to the CRT. In these latter two cases, you'd be stuck with CRTs and valves as the standard technology, which means that you get to use nixie tubes, which means that you've won the internet even in a universe with no internet. You win yourself a lovely retrofuturistic technopunk world. People might wear disabled ICs as jewelry in the same way that steampunks wear cogs. ]
[Question] [ Imagine a world where only precious metals are available. They are as common and plentiful as iron or aluminum are in our world. Any metal that is not precious does not exist outside of biological forms, like the iron in our blood. Taking this into account, which metals, or alloys, would be the most used for tools? Things like axe heads, pickaxes, knives, etc. For the purpose of this question, let's use the wikipedia's list of precious metals: <https://en.wikipedia.org/wiki/Precious_metal#Rough_world_market_price_($/kg)> [Answer] ## Palladium White Gold Jewelers have spent centuries learning to alloy precious metals in ways that make them strong enough that they can include tiny details without being too delicate. While pure golds (24k) are soft and delicate, but golds between 14k and 18k are a lot tougher than most people give them credit for. Cast gold is usually used in jewelry making meaning that lower karots are often needed to get desired hardness and toughness, but like bronze, these are typically work hardened alloys. If you were to cast a typical 18k gold, and hammer it into a blade or armor, the resulting alloy would have a hardness and tensile strength slightly better than a 1055 rolled medium carbon steel. The ideal gold alloy for this is a mixture of about 75% gold, 20.5% copper, and 4.5% silver. Unfortunately, Copper is not on the list given by the OP (despite being on many other precious metal lists); so, we need to look to other gold alloys with similar properties if we want to meet the OPs specs as asked. This is where the palladium comes in. Palladium is sometimes used to substitute for copper or nickel in gold alloys because it gives a similar hardening factor when caste while also being hypoalergenic... but unfortunately, it does not work harden like copper gold alloys. Instead jewelers add Ruthenium to Palladium Gold alloys until it reaches its desired hardness. This alloy wont be quite as durable as a work hardened copper-gold alloy, but it can get pretty close. The resulting alloy should be about 60% gold, 15-20% silver, 15-20% palladium, and 5% ruthenium, and you will be suitable for a wide range of tools using only the elements on the OP's list Ultimately, the resulting alloy will be just as tough as a lot of the weapons and tools made throughout most of the iron age, but the metal will be more dense and heavy. So, you will likely see a lot of shorter weapons and tools. A gold alloy gladius or kopis might work even better than early steels because the higher density will give you more power without broadening the blade profile, but don't expect any long swords or full plate armor since the increased density would make those prohibitively cumbersome. [Answer] # Beryllium, all over the place... Beryllium is not even remotely related to what most people consider to be a precious metal, but it’s on some lists of precious metals (including the one the question states to use as a source) for two major reasons: * It’s comparatively rather rare. Not as much as the platinum group metals or gold, but enough that it’s abundance within the earth’s crust is best measured in parts per million. * It’s absurdly useful stuff. Beryllium is actually a surprisingly good structural material. It has a rather low [Poisson ratio](https://en.wikipedia.org/wiki/Poisson%27s_ratio), a [bulk modulus](https://en.wikipedia.org/wiki/Bulk_modulus) not much lower than steel, a [shear modulus](https://en.wikipedia.org/wiki/Shear_modulus) and [Young's modulus](https://en.wikipedia.org/wiki/Young%27s_modulus) much higher than steel, and a lower coefficient of thermal expansion than steel. It’s also reasonably hard without being too hard to be useful, and has an absurdly low density for a metal (1.85 g/cm³, compared to 1 g/cm³ for water and about 7.85 g/cm³ for typical steels). Of the metals on the list being used here, beryllium is the single most useful option, and it will be used almost everywhere. --- Other things to note: * Hammers and other things that need to be heavy will probably use platinum or a platinum-iridium alloy. * Osmium-iridium alloys are likely to be used for things where weight is negligible or does not matter, but durability is super important. They even beat out tungsten by some measures of durability. * There will be no real replacement for applications we currently need super-hard materials like tungsten carbide for. You simply cannot get to that point using just the metals on the list. * Copper is going to be super valuable here for a number of reasons. [Answer] ### Eternal Stone Age or Advanced Space Age None of those metals on their own are particularly good for use as large tools. Gold doesn't make a very good axe and silver doesn't make a very good weed whacker blade. So, absent any kind of cool alchemy, people would most likely continue on with tools fashioned from stone, wood, laminates, bone, etc. Small tools, like surgical instruments, spectacle frames, weights, food vessels and so forth are all viable contenders for being made from almost any precious metal. (Would stay away from gallium dinner plates, though!) However, if you allow for curious alchemies, there are [alloys of precious metals](https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201802026) that could prove to be viable in tool making. One could argue, perhaps, that the concept of mithril, hard as steel, lustrous as silver, is just such an alloy. [Answer] If Iron is available in biological forms, it could make for quite grim stories of harvesting it. There might be ceramics (you might want to avoid the most obvious one, BeO, due to its horrible toxicity...) and amalgams based on only precious metals not known to our science because nobody looked hard enough, for lack of a practical application. And do not underestimate good old carbon... as diamond, or carbon nanotubes, it could be useful in quite many tool applications. [Answer] While a world that follows the premise of the question has serious issues to face, just going along with it, I think you might find this wiki page helpful. [Hardnesses of the Elements (data page)](https://en.wikipedia.org/wiki/Hardnesses_of_the_elements_(data_page)) In such a world there would be alloys that we've never even thought of trying to make, and they would likely find some alloy that solved their problems. However, if we're sticking with pure elements, of particular note is rhodium, the first element on your list of precious metals, which has a Brinell hardness of 540, comparable to abrasion resistant steels used in the mining industry and much harder than things like cast iron or even tool steel. It is also durable, so it doesn't wear easily. It's a noble metal, and like all of that family is is very non-reactive. It's not perfect, of course. Its biggest drawbacks are that it is brittle and that it has a high melting point. I don't know if anyone has ever simultaneously possessed enough rhodium and had the desire to make a hammer or axe head out of it. In its pure form it can't be made into good jewelry because it's tool brittle and the jewelry breaks. That said, a large lump of it is a different question, and it would definitely be possible to chop down a tree with an axe with a rhodium head. Breaking rocks? The pick/hammer might shatter or chip, depending on the hardness of the rock. However, again, it should be comparable to AR steels, and they're used for mining purposes. It melts at 1538°C (3565°F). This is above the temperature that a coal/air forge can reach, so it couldn't be cast using coal to melt it. To be clear, it would be able to be heated to workability in such, and since it is typically found as an uncombined metal (like gold, basically) it should be able to be forged into a lump and then further into whatever shape is needed. It is apparently quite difficult to machine - there are numerous machinists complaining about it ruining their tooling on forums. Neither better nor worse really, but worth considering, is that it is also ~1.5 times denser than iron, so any tools would be heavier (or smaller). Finally, if weapons are a consideration, it would be fairly awful for most of them. It would potentially make a ferocious projectile weapon (arrowhead or bullet, that is) but a large, chunky sword or axe would be too heavy for human scale muscles to use effectively and a thinner weapon would be too easy to shatter. I guess that might actually pose an interesting challenge to duelists - not quite as bad as fighting with glass swords, but a similar idea. ]
[Question] [ The world has a [Plot Device Treaty](https://worldbuilding.stackexchange.com/questions/100133/aerial-surface-assault-without-bombs-explosives/100213#100213) which, being a Plot Device, bans aircraft from being effective against ships. As we have seen from history, such treaties are often violated, circumvented, or otherwise rendered ineffective. I need a plausible reason for countries to be uninterested in bypassing this treaty. Especially since, at some point, someone will realize just how powerful and cost-effective aircraft can be. The time period that this Plot Device Treaty is written in is similar to the 1920s - Early aircraft, with some visionaries but many who are disdainful and actively trying to undermine it. Many of them have political power after the Big War, so passing the Plot Device Treaty isn't an issue. The time the story is set in is equivalent to the 1950s in technology, so it's 20-30 years that this treaty has been in effect. It doesn't need to be enforced much longer, as Big Things happen in the story that render the Treaty largely irrelevant. With multiple nations involved (Some of which really dislike each other) and at least one significant (Perhaps world-spanning, perhaps not. Haven't decided) war, how would the countries be enticed to follow the treaty? [Answer] If you replace in your story the "airplanes" with "nukes" you have pretty much what happened with nuclear weapons. The various treaties signed over the years have been observed thanks to: * mutual surveillance: each superpower could check that the terms of the treaty were being observed by the others * a third party agency monitoring * political willingness from all the involved parties Yes, there have been nations not observing or even signing the treaties, but I think you also want those elements in your plot. On the other side, airplanes are far from being as lethal as nukes. You can hardly set up MAD (mutual assured destruction) just because you have airplanes... You probably need to tweak a bit on the reasons behind why there is such a vast consensus over banning airplanes. [Answer] Such treaties are often accepted and upheld, because the consequences of not upholding them are terrible for everyone involved. Weapons of mass destruction are the typical example of this, but the general principle holds for other things. Thus, I propose that you find a reason why, in your world, it is really important not to hunt down ships. Maybe ships are also built from hard to replace resources. Maybe the layout of your world makes naval transport really common and integral to the functioning of society. This would be especially true if many countries depended on sea access for basic goods such as food, fabrics, fuel and similar things. Goods whose loss will severely impact the civilian population of every country, leading to the deaths of thousands of innocents through starvation, freezing etc, thereby also crippling wartime production but doing so with a huge price. Then, make sure that this weakness holds true for all relevant nations (possibly with different goods for each), so that if one country starts sinking ships with planes, every country can do so and everyone suffers more than they are willing and/or able to bear. [Answer] Chemical weapons in WWII. Both sides had them, both knew that the enemy had them as well, but the balance of terror held. * This assumes all sides have plot device capable aircraft, and there might be episodes like civil wars or suppression of revolutions where they are used. * Military planners would be aware that the enemy might deploy plot devices when push comes to shove, so they'd have to think about countermeasures. They'd be aware that those countermeasures will fall short, so the balance of terror holds. Strong neutrals who push for the treaty. A bit like the right of neutrals to trade with belligerents during early WWI. * The right to sail merchants through a blockade is something understandable to the man in the street. The right that one foreign country doesn't bomb another foreign country is harder to grasp in those terms. * It might help if the neutral power is truly neutral and if it does not want the outright victory of one of the belligerents. Their preference would be that they exhaust each other. [Answer] While nations are at peace and trading with each other, nobody has any particular vested interest in breaching the treaty. It's only once war starts that it will rapidly start to fall apart. Either the war is rapidly won, or such treaties become casualties. Operations like [Ministry of Ungentlemanly Warfare](https://en.wikipedia.org/wiki/Special_Operations_Executive) will be set up and one of the things they'll look at is a way round such a treaty. Victor's justice, assuming the nation that broke the treaty is victorious, will mean that the treaty is just another casualty of war, along with the other various trade and peace treaties that existed before the war broke out. [Answer] The Big War was shorter than the Great War or World War I. Too short for aircraft to be proven as effective weapons of war. Originally, aircraft, which included observation balloons, were mainly used as reconnaissance vehicles to determine enemy positions, troop concentrations, military facilities, and artillery emplacements. It took time for them to be used as fighting machines. This suggests if the Big War was over faster then the effective military development of aircraft might be missed. Alternatively, this was a world where the development of aircraft was either slower and hadn't progressed as far when the Big War broke out. This could mean aircraft had to undergo much more development and innovation than in our reality. A major factor in a quicker version of the Big War could be that world's equivalent of Germany failed to invent the [Haber process](https://en.wikipedia.org/wiki/Haber_process). Germany was on the verge of running out nitrates for the use in their munitions (artillery shells, bullets and explosives). Nitrates were mainly imported into Germany. The Haber process enabled the synthetic production of nitrates, thus prolonging World War I. > > During World War I, the production of munitions required large amounts of nitrate. The Allies had access to large sodium nitrate deposits in Chile (Chile saltpetre) controlled by British companies. Germany had no such resources, so the Haber process proved essential to the German war effort.[9][11] Synthetic ammonia from the Haber process was used for the production of nitric acid, a precursor to the nitrates used in explosives. > > > A combination of all the above suggestions could result in a situation where military aircraft weren't sufficiently developed to be a threat, but their potential may have been becoming obvious. Therefore, a Treaty to ban their use would be likely to be passed and its enforcement would be easy. No-one fully realized the potential of air warfare and believed they could do without the cost of the research and development. This, of course, would be a world without air travel. [Answer] The simplest answer is that there are two large powers who are: * Neither friendly nor particularly unfriendly towards each other (think late '90s China vs USA) * Reliant on naval power (both civil and military) Both have a good reason to limit the development of anything that makes ships vulnerable, and the power (economic, diplomatic and military) to keep the Status Quo. Neither power will want to risk developing the devices themselves, as this will likely erode their power relative to smaller nations in time to a sufficient degree to make their temporary advantage over the other power un-worthwhile. No smaller power can risk the wrath of the two larger powers. Then have the treaty enforced by inspections, etc and off you go. The chances are though that such things will fall by the wayside on day 1 of a major war - but there is a reasonable chance that if the treaty has been successful, that development will be at a very basic stage when things kick off. [Answer] # States obey treaties that are in their best interest. Period. States choose to obey their agreements (treaties) simply because the rulers believe that it is to their advantage to do so. A corollary is that States are likely to promptly break or violate agreements if they believe that greater advantage will accrue. 'Advantage' can be political, military, financial, personal, etc. Often it's more than one. And that's your opening as an author. When looking at treaties, it often helps to look through the lens of Advantage. There is often prestige and strategy involved...and occasionally corruption, too. It's a rich tapestry. Successful treaties since 1945 tend to include: * Multilateral institutions to transparently handle inspections, to reduce espionage, and to prevent secret abrogation * Clear designation of accountability for overseeing execution of the treaty, like the UN Security Council or the International Criminal Court * Specified methods of resolving disputes like multi-party talks, sanctions, referrals to UNSC or ICC, etc Just like earlier treaties, States participate when they feel that it in their best interest to do so. And states will drop out when they feel it is not. The post-1945 additions do two relevant things here: They push the development of international institutions as important and relatively impartial players, and they discourage states from cheating or dropping out by clearly expressing the consequences to their Advantage. One example of a successful multilateral treaty is the [Vienna Convention](http://ozone.unep.org/en/handbook-vienna-convention-protection-ozone-layer/2205) of 2009, which is allowing the Ozone layer to regenerate. However, a more instructive example of a less effective treaty may be the [Washington Naval Treaty](https://en.wikipedia.org/wiki/Washington_Naval_Treaty) of 1922, which briefly limited the construction of large warships. * Many were interested in reducing costs due to the post WWI recession * Competing interests and jockeying for advantage scuttled the proposed prohibition of submarines * Japan was willing to accept lower numbers because it had greater concentration than it's more industrialized competitors * It unexpectedly caused a building boom in some types of ships * There was no inspection nor enforcement mechanism, making failure of the Treaty likely after a few years. Sure enough, the treaty lasted less only a decade The upshot: If you really want to ban aerial bombing before 1945, you have the League of Nations available to carry out the institutional roles. You can crib consequences and sanctions from current arms control treaties. You can justify initial Advantage for a different reason in each country: A recession, a currency collapse, a failed coup, fear of a more technologically advanced neighbor, war exhaustion, and many more. [Answer] A lot of other answers are correct in saying that retaliation is the primary motivation for using prohibited weaponry such as chemical or nuclear weapons. However, in order for this to be true, there must also be few, if any, effective countermeasures to such weaponry. Chemical weapons are avoided because you can't really defend against them effectively. So although they might be effective against your enemy, they will be equally as effective against you. Nuclear weapons are avoided because missile defense systems are pretty dodgy and you can't rely on them. If it was possible to effectively defend against nuclear missiles, their use would be much more likely. Cold War actors recognized this early on and 1972 the US and USSR signed the [Anti-Balistic Missile Treaty](https://en.m.wikipedia.org/wiki/Anti-Ballistic_Missile_Treaty) which limited the scope of each nation's missile defense systems. However, in your example of limiting the effectiveness of aircraft against ships, I doubt that no nation would be unable to develop countermeasures against aircraft. Anti-aircraft guns are simple to make and bullets are cheap. Ships equipped with anti-aircraft gunners could easily provide a defensive screen for a nation's ships that could limit damage. Although opponents would also have anti-aircraft guns, I could see a nation deciding the potential benefits outweighing the risks and believing that they could increase their effectiveness through better training and/or tactics. In order to entice nations to follow the treaty, you want to throw off this cost-benefit analysis so that breaking it by using aircraft against ships is simply not worth it. One way I think you could do this is by decreasing air density (or increasing temperature, see [this answer on the Aviation SE](https://aviation.stackexchange.com/a/1532)). Decreasing air density or air temperature will make it harder for planes to take off, requiring either longer runways or redesigning planes. While longer runways is easy enough on land, it isn't really feasible for launching off ships: a longer runway means a bigger ship which means a bigger and more expensive target. Since aircraft carriers are often the most expensive and heavily crewed ships in a fleet, nations may want to avoid building them altogether. Even using steam catapults would be hard, as they'd need to be more powerful and they are already extremely heavy and dangerous equipment on board ships. An alternative of course is to redesign your planes, you could make wings larger, which means more lift but it also means they take up much more space on board your aircraft carrier which means you can't carry as many planes, once again limiting their effectiveness. It could also mean lighter aircraft by carrying fewer explosives, which would of course limit their effectiveness against ships to begin with. I'm not sure how much less dense air would have to be in order for this to be effective and there may be other side effects I'm not thinking of here, but that's out of scope for this question. Edit: I forgot something else! A thinner atmosphere would also force planes to fly at a lower altitude, making it easier to hit them with anti-aircraft weapons. [Answer] Because using them causes Very Bad Things(tm) to happen All the other banned weapons have this one trait. Chemical warfare is banned because it is indiscriminate, causes mass death, even on both sides, can't be protected against and destroys everything it touches. Nuclear weapons are the same plus extra world ending sprinkles on top. Logically it makes no sense to ban the use of aircraft to sink ships if ships can also sink ships. Both result in a sunk ship. The main difference between aircraft and other ships is where they operate : the sky. Ships also operate on the open ocean, where as other forms of warfare happen on land. Thus for a very specific treaty like this, you need something bad to happen when aircraft operate on the open ocean. For the time period you have mentioned, aircraft were not yet capable of high altitude warfare with naval ships, they needed to be fairly low to hit them with anything. So we could limit this to low altitude aircraft over the open ocean, so that passenger aircraft and air to air combat is still viable. For an example, we could imagine a very populous migratory bird that traverses the open ocean continuously and goes to the continental mainlands around the world at certain times for breeding or whatever. They are highly tuned to see objects at their flying altitude and follow them in big chains of migrating birds. When aircraft fly near these altitudes the birds become confused and huge swathes of them die from going off course and never reaching land. The impact of this happening after the first few occurrences begins to show itself as significant portions of the ecosystems worldwide go haywire and entire crops and other species start to die off because the magical ocean minerals the bird poo provides the soils aren't present. A treaty is created that forbids low altitude aircraft over any portion of the ocean more than 5 miles from the coastline. Provisions are put in place that forbids weapons development for aircraft to target naval ships so nations aren't enticed to try to use them anyways. Later on maybe research finds that aircraft created in certain shapes or colors don't trigger this effect, or high altitude bombing becomes a thing. There are other situations that could prove highly damaging that would cause a treaty like that to be signed but it needs a component that makes not adhering to the treaty very dangerous for everyone. [Answer] As answered have said - there needs to be a deterrent to ensure treaties are enforced. But you don't need to revert to pre-treaty days against an adversary who breaks them. eg. Dropping chemical weapons on an adversary who has started to use them. Instead you hit them with other deterrents, such as trade embargoes or asset freezes. A country unable to trade with anyone else is either so powerful they can do what they like anyway, or will quickly crumble and end up as a feeble dictatorship followed by collapse, and either way the rulers will not be able to get and enjoy their riches as they otherwise would. I think most treaties have punishments either written into them, or the organisation managing them has deterrent powers to bring to bear, with the means to force other treaty signatories to be involved in enforcing the deterrent. In these cases, a lot of countries would find it in their interests to damage the offending country - to steal their trade or seize their assets for example. [Answer] I don't know how similar or different your world is. One way to make such a prohibition is for every major power to be heavily invested in civilian merchant ships, and naval ships of all types up to battleships. Possibly the major powers have so much capital invested in shipping that is expected, unlike most ships in our world, to last for decades into the future, that several forms of sinking civilian and naval vessels have been banned such as mines, submarines, and airplanes. Another way is to make airplanes banned as weapons of war. The first major uses of airships and airplanes have been as terror weapons, and so all use of warplanes is abhorred and prohibited. The leaders of the first nations to use airplanes in war have been executed for so doing, setting a legal precedent. Or maybe the officers and men who carried out those missions have all been executed, making all future soldiers reluctant to obey such orders. A third possibility. Maybe petroleum based fuels and internal combustion engines have been introduced much later in your world. A decent merchant marine and battleship navy can be propelled by steam engines and coal, while coal and steam powered airplanes would be every inefficient. A fourth possibility. Maybe in your world a nation's airspace only extends to the height of a skyscraper above the ground and the air above that is considered to belong to everyone like the open oceans. And maybe in your world flying is considered to be a glorious and sacred activity and it is considered sacrilegious to defile flying with commercial or military use. A fifth possibility. Maybe after the last big war where a lot of new weapons were introduced treaties were signed forbidding the use of ANY technological innovations in war, not just airplanes. Possibly the victorious nations feared that technological innovations could favor their rivals, while the war weary populations of the losing nations blamed new technologies for ever increasing devastation and death tolls of wars and demanded a halt to the development of new weapons. Possibly some combination of some of those five suggestions would suffice to explain the non use of airplanes against ships in your world. [Answer] Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. Economic consequences for violating the treaty seem like a good motivation. There could be also a organisation like the UN ... Or maybe you send agents to the weapon factory's to make sure these facilities follow their orders. ü§î [Answer] As many of the answers have said, you're going to struggle to convince a nation; a power not to abuse a treaty for an easy win. I would advise against the planes are like nukes mentality as it doesn't really make sense. The total destruction of civilian centres is just not the same as sinking an enemy ship - it never will be to your audience either. However there is a somewhat simpler way (depending on how much control you have over histroy): Let's say that the countries involved in this war are all either Phristian or Pewish (no offense intended on either). The religious backgrounds hold a similar thread up to a point. As it happens one of the tales of old is how Abraham sought to call down God's wrath on his enemies - destroying their boats from the air using gliders deployed from nearby mountains ([this was plausible with 500AD tech](https://en.m.wikipedia.org/wiki/Early_flying_machines)). But God was displeased with Abraham; God and God alone may rain hell fire down from the heavens, Abraham was punished by God etc., Skip forward 2000 years and everyone knows you don't rain hellfire or God will rain it on you. It's not quite a commandment, but it's certainly not the Phristian thing to do. The people would be appalled if their government decided to go against the moral will of the country for something as petty as a boat. With a little writers poetic license and something a bit more buzzy than you don't rain hellfire or God will rain it on you, you could make upholding the treaty be a move based on national (not international) politics. ]
[Question] [ How can I find the area of an irregular shape while taking into account the distortions of Equirectangular projection? [Answer] Nations likely have borders that can be approximated as many connected line segments, and can therefore be approximated as polygons (in some cases, borders and straighter, depending on the political history of the country). Let's say you pick a set of $n$ points on the border and draw straight line segments between them. The resulting polygon is approximately the shape of the nation. Give point $i$ the Cartesian coordinates $(x\_i,y\_i)$. The formula for the [area of the polygon](http://mathworld.wolfram.com/PolygonArea.html) is thus $$A=\frac{1}{2}\left[(x\_1y\_2-y\_1x\_2)+(x\_2y\_3-y\_2x\_3)+\cdots+(x\_{n-1}y\_n-x\_{n-1}y\_n)+(x\_ny\_1-y\_nx\_1)\right]$$ For anyone who's curious, this arises as a sum of determinants. It can be applied to continuously differentiable parameterized borders via [Green's Theorem](https://en.wikipedia.org/wiki/Green%27s_theorem#Area_calculation). If you want to take curvature into account, things get a bit trickier. Each line on the surface of the planet - which we'll model as a sphere - can be viewed as an arc of some angular length $\theta\_i$. The [area of this spherical polygon](http://mathworld.wolfram.com/SphericalPolygon.html) is now $$A=\left[\left(\sum\_{i=1}^n\theta\_i\right)-\pi(n-2)\right]R^2$$ where $R$ is the radius of the planet and $\theta\_i$ is the angular length of the arc connecting point $i$ and point $i+1$. You need a pretty large $n$ for complicated countries, but for countries like Egypt, for instance, you only need a few points. Here's an example of how I'd lay out points on a map ($n=7$): [![enter image description here](https://i.stack.imgur.com/hASXX.png)](https://i.stack.imgur.com/hASXX.png) Original image from [here](http://egyptmap.facts.co/). Like sphennings, I'd recommend ignoring the curvature of the planet. For most small nations, the difference will be minimal. [Answer] The most precise and easiest way to find it is to use a software. 1. Scan your map if it's not already on a computer. 2. Use a free software like [the Gimp](https://www.gimp.org/fr/) to modify the map. 3. Paint the area in a specific color, using plain colors (no gradient). 4. Save a copy in .PNG. 5. Go get a software called [G projector](https://www.giss.nasa.gov/tools/gprojector/). It's made by NASA and will allow you to change the projection. 6. Convert the map to an equal area projection like Hammer. Then save the result in .PNG. This kind of map projection solve the size distortion issue. it mean every area on the map will have the same size as in reality. 7. Load this news map in Gimp and use the magic wand on the color to find out how many pixels it covers. 8. Use the wand again to find the total number of pixels for the whole map. 9. In order to find how big the area is, divide the pixels of the area by the total number of pixel. It gives you a percentage of the total map covered by your area. 10. Lastly, multiply that percentage by the size of the world in square miles or square kilometers. If your world is about the same size as Earth, it should be around 550 million square kilometers. [Answer] Answer: [Surveying](https://en.wikipedia.org/wiki/Surveying) Just like we find the area of our own nation today, employ or use modern surveying techniques to find the area of your land mass. If you are simply looking for existing areas Wikipedia contains such information for just about every known land mass. How surveying works: all you need is 3 points and know the distance between 2 of them. Using basic trig you can calculate the third distance easily. Once you have a triangle established on the ground you can get its surface area easily. you expand your area by making more triangles contiguous to your original. This is handy because you already have 1 side measured, you just need to measure a 2nd. As you make more triangles just sum up their area as you go. The more/smaller triangles you make, the more accurate your solution will be. Accuracy here is limited purely by your will and resources. [![picture of random shape divided into triangles](https://i.stack.imgur.com/TrGz9.gif)](https://i.stack.imgur.com/TrGz9.gif) How this completely solves the question: The OP provided no limitations what so ever that would prevent him from employing this method. This is the method that we use today and its brutally simple. Fun fact Coincidentally this is also how 3D graphics work to an extent, lots of triangles forming a mesh that outlines an object. I also want to point out all the software links that people posted( this is basically how they work). [Answer] Determining the area of a landmass has traditionally been done by subdividing the landmass into smaller segments of known area and then calculating the total. If you're dealing with a fantasy map trace over the map on some graph paper and estimate fractional values for any squares on the border. This should get you an accurate enough estimate for most purposes. I'd ignore the complexities that come from the projection. Most fantasy/sci-fi authors aren't considering it when creating their maps. It's not worth the headache. [Answer] This is a scientific, geodesy-based answer. I assume we are talking about the earth and that your dataset is an image. First of all, you need to figure out what metadata you have. Knowing the projection to be equirectangular is a big first step, but other questions arise: does the map cover the whole globe? Do you know its georeference (i.e. coordinates of the lower left pixel, pixel size)? If neither is true, it won't be fully possible to determine the area, since areas near the poles appear much larger than they really are (in this projection). So if you can't tell whether your country is on the equator, near some parallel, or at the pole, it will be a lost cause. Otherwise, try loading up the image into the open-source GIS [QGIS](http://qgis.org/en/site/). It should prompt you to set a projection, where you can select one of the equidistant cylindrical ones (e.g. EPSG:53002, which assumes a spherical earth with R=6371000m). Then you can use the "measure" tool from the toolbar to select some points on the map (HDE's answer applies here) and get the area. You can also go to the [GIS Stackexchange](https://gis.stackexchange.com/) if you have further problems with QGIS. The most important thing, however, is to figure out the georeference of your map. Some information on how to do this with a real-world paper map is given [here](http://docs.qgis.org/2.14/de/docs/training_manual/forestry/map_georeferencing.html). This method requires you to select points with known coordinates on your map. [Answer] You can't do it perfectly but this should get you close. The problem with the projection in question is that you can't know from the map alone (still less from a fragment dealing with a particular nation) how much distortion you are dealing with. So to get a good estimate of the actual area you need know how large the world in question is and the rough lat-long of the area under question, that will allow you to estimate the amount of "stretch" that has gone on during the mapping process, but that's all it is, an estimate. This estimate is represented by [Tissot's Indicatrix](https://en.wikipedia.org/wiki/Tissot%27s_indicatrix), [here](https://en.wikipedia.org/wiki/Equirectangular_projection#/media/File:Tissot_indicatrix_world_map_equirectangular_proj.svg) is the estimate for the equirectangular, or equidistant cylindrical, projection. For locations close to the equator the distortion is minimal to non-existent, the higher the [latitude](https://en.wikipedia.org/wiki/Latitude) the more distorted the view becomes. Stretch is along the longitudinal axis, parallel to the equator, only. So to get accurate area measurements you need to gauge and correct the distortion. To gauge the distortion there are two methods: Method one I'll call the North-South method, to use this method one needs to establish a [longitude](https://en.wikipedia.org/wiki/Longitude) fix. For that you need two points on your map that you know are on a direct north-south line, AKA they share a line of longitude, in the real world. Then look at where they fall on the map, as long as they don't fall on the central longitude, the line should be on an angle off the vertical. In reality the degree of distortion falls along a curve but the angle will do for close estimates. The angle of this line will give you a good estimate of the degree of distortion along that longitude and the map in general. Measuring the difference between the longitude fix line and the vertical at any point will give you the factor of distortion at that latitude and you can correct you east-west distances at that latitude, you'll need to do that at all latitudes to get a correct polygon for your country. Note that only the East and West borders will move, equirectangular projections are, in a perfect world, completely accurate when it comes to North-South distances and the shape and position of the northern and southern borders. Note also that finding a fixing point from which to make the above corrections is not always easy, it can't be done from the map alone, the two points must be on the same side of the equator, and should be as close to the north and south edges of the map as possible to get a good cover for the whole map, said points should show the same degree of distortion regardless of longitude provided they do not fall on the "central longitude" of the projection. Method two I'll call the East-West method, this method measures entirely along a given latitude, or a series of latitudes, again it relies on known, real world positions for points and more importantly the distances between points in this case take two points on an East-West line and measure the mapped distance between them, compare this to the real world distance and correct the map along that line by the percentage of error. Both methods will render a distortion/corrective factor that can be expressed as a percentage, for small areas/countries that span only a few degrees of latitude the distortion is relatively uniform and can be handled with a "factor-based reduction" say the distortion is +10% along the central latitude of a country several degrees (say 300km) north-south then to get reasonably accurate east-west measurements reduce all these distances by a factor of 10% since the variance of distortion over that small a distance will be minimal you needn't correct individual latitudes separately. For countries or areas that span a large amount of latitude you will need to make correction at a number of latitudes if you want good accuracy as the distortion increases with distance from the equator. If the country straddles the equator the equatorial distances should need no correction but take care if using the North-South method that three or four points are used one or two on the equator and the other two as far north and south as possible. In an accurate equirectangular projection the distortion should be symmetrical at matched latitudes north or south of the equator, but I'd check rather than assume. So that's correcting the distortions of the projection, then it's all about [polygons](https://en.wikipedia.org/wiki/Polygon), break the map down into as many smaller areas as necessary to get full coverage of the space and calculate those areas separately. Note this is easiest if you just use triangles, lots and lots of triangles since any polygon more complex than a [quadrilateral](https://en.wikipedia.org/wiki/Quadrilateral) will effectively be broken into triangles during the area calculations anyway. The in-world alternative is to ignore the map and do what the English did in their real-world colonies and actually measure it physically with [chains](https://en.wikipedia.org/wiki/Chain_(unit)), they surveyed the entirety of India by physically measuring the land. There are alternative survey methods but the chains are pretty well idiot proof, they also don't bend to local gravity distortions like those found near mountain ranges like the Himalaya. Please note that all the above methodology for correcting maps assumes that the map in question is accurate which with medieval or earlier mapping techniques is by no means a given. [Answer] Many answers have been given, some of which are really rather complex (but I trust that they're accurate). I'll try to give you a different method which is less complex. The tools you need are relatively simple: * A scale. * Plenty of paper with the same thickness. * Scissors. * The ability to accurately draw the country's borders. Forgoing the projection problem: 1. Draw the country on a piece of paper and cut it out. 2. Compare the weight to that of rectangular pieces of paper. You can of course easily calculate the surface area of the rectangular paper, which means that comparing its weight to that of the country's cut-out will give you the exact surface area of the country cut-out. Solving the projection problem: 1. Make a paper sphere. 2. Draw the country on the sphere and cut it out. 3. Compare the weight to that of rectangular pieces of paper. --- This method can only be as precise as your drawing (and cutting) skills, and you'd expect more of a rounding error when you use a smaller piece of paper; but the underlying physics are sound. [Answer] There is no good answer to your question. The Earth is approximately a sphere. When you try to map a sphere on a flat sheet of paper, or a flat monitor, there must be some distortions. Those distortions can be in distance, angle, area, or all three of them. What you can do is to start with an [equal-area](https://en.wikipedia.org/wiki/Lambert_azimuthal_equal-area_projection) map projection, especially when you draw it yourself, from scratch. But that will mean your map will be "weird" -- in the example given here, one point on the planet becomes the entire boundary of the map. Then you are left with calculating the exact area of a country on your paper, which itself isn't simple, especially if the borders look like "historically grown" European ones rather than the lines-on-a-map of much of North America. A bit of googling gives some software to transform one map projection into another, but I haven't tried them myself. --- Follow-Up: Look at this file with a [Mercator projection](https://commons.wikimedia.org/wiki/File:Mercator_projection_SW.jpg) of a world map. Now look at this [Lambert projection](https://commons.wikimedia.org/wiki/File:Lambert_cylindrical_equal-area_projection_SW.jpg). Compare the size of Greenland, for instance. Both maps are "right" for some purposes and "wrong" for others. A file without information about the projection that was used is just a pretty picture, not a map. [Answer] I thought of a way to measure the area of a country on a map directly using fluid displacement. 1. Trace country on a 1 cm thick flat sheet of clay. Cut it out. Or use wood and a jigsaw. 2. Get a clear rectangular container such that the bottom of the container is large enough to hold the cut out country flat on the bottom. 3. Fill the container with known quantities of water in measured increments. For example 20 cc at a time. Mark along the side of the container the water level for each volume of water. 4. Put a known quantity of water in the container. Then put in the clay map. It should be submerged. 5. The map will displace water equal to the volume of the map. This can be determined by subtracting water level without the map from water level with the map. 6. A cc is a cubic centimeter. The ccs displaced will equal the area of the map, because volume = area \* height and height here is 1 cm. 7. This would work with a curved map / piece of clay as well, as long as the clay representation remained of uniform thickness so you could divide out the thickness. --- Or simpler, without the water! This measures weight instead of volume and relies on a predictable weight to volume ratio. 1: Smash your clay into a 1 cm sheet. 2: Cut out a square of dimensions adequate to surround your map country (once cut out) 3: Measure area of square. 4: Weigh square. 5: Cut traced map out of center of square. 6: Weigh clay map 7: The ratio of clay map weight to clay square weight is the same as the ratio of map area to square area. Solve for map area. If you have access to a pharmacy scale capable of accurately weighing pieces of paper you could do this with just the paper of the map. Draw a square around your country on the map, cut it out, measure area of square and weigh it. Then cut your country out of the square and weigh that. Ratios are as step 7 above. [Answer] Your map is in a file? Rasterize it if it's vector based. Run it through the software to transform into an equal-area projection, noted in earlier answers. Then get a color histogram: how many pixels are in that nation’s color? Divide by the pixel area of the projected file, and multiply by the scale area of the map. --- Update: I see Vincent already described this in more cook-book detail, 2 months ago. So why is an answer still needed? ]
[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/45276/edit). Closed 7 years ago. [Improve this question](/posts/45276/edit) In my world I have a civilization in which all members have a collective consciousness like [the Borg](http://memory-alpha.wikia.com/wiki/Borg) do when they originally appeared on Star Trek. Unlike the Borg, this collective doesn't (usually) spread through conquest; they prefer to have volunteers join them. Since they still need to spread around the universe, what might be some of the reasons for other civilizations to join the collective. The answer must be something that will apply to several civilizations regardless of race (note I said several civilizations not all civilizations). [Answer] Immortality is incredible bait. Contribute your mind to our collective, and it will live on, even after your body passes. Drones don't have to be created only from the bodies of new recruits, they can be cloned and filled with the minds of members whose original bodies have died in service to the collective. [Answer] This wouldn't happen on the civilization level, but it would probably result in a steady stream of volunteers: Wanting a place to belong or feel like you're not alone. People don't always have the best lives, and those who feel downtrodden or lonely would likely have ample reason to join a collective. If you want some real life examples, cults and organizations that give people the feeling of belonging happen all the time, some even getting so large that they can be officially recognized. So, while other civilizations wouldn't necessarily join wholesale (and even if they did, there would likely be members who refused to participate), it would still provide more than enough immigration and consolidation into the society/collective as long as it was advertised effectively and not demonized by the other civilizations. [Answer] The human race has already entered into a collective consciousness in the form of the internet. This collective consciousness is much more primitive than that of the Borg, but with time one can certainly imagine it evolving in the same direction. What is needed are: 1. Improvements in computer/human interface that make it possible to communicate with computers (and by extension, with other people on the internet) just by thinking. 2. Widespread adoption of internet voting for making important decisions. 3. Improvements in virtual reality and other technologies that obviate the need for direct human-to-human contact. So the reasons that another civilization might be interested in joining a collective consciousness are exactly the same as the reasons that everyone in our current civilization likes the internet so much. Being part of a collective consciousness is fun. It is intellectually stimulating, and it helps to fulfill the basic need that humans have to connect with other people. Of course, there is a dark side to joining a collective consciousness, which is that you lose some of your free will. Instead of acting on your own behalf, you begin to cater to the needs of the collective. For example, there is no innate reason that I should be willing to write an answer this question, but the collective consciousness has decided to reward good answers with fake internet points, and I care enough about fake internet points that I've chosen to subsume my will to that of the collective. If you want another civilization to join your collective consciousness, the easiest way to convince them is simply to start sharing it. This involves building certain infrastructure, but as soon as the infrastructure exists individual members of the other civilization will begin to join, simply because participating in the collective consciousness is entertaining. For a sufficiently advanced collective consciousness (far beyond our current internet), it should only take a decade or so for the entire social, political, and economic system of the other civilization to be subsumed into the collective. [Answer] Your question(s) bring to mind recent discussions about a hypothetically approaching "singularity" in our own civilization. In Vinge's novels, sometime a few hundred years from now, voluntarily cybernetically augmented minds found advantage in joining, losing some elements of individuality in exchange for experiences that span centuries and billions of lives. Recently, with the ever rapidly increasing pace of technological growth, it is often said that "computer literacy is as crucial to an individual as written literacy". Essentially, that you are able to ask your question today, in a 'hive' of intelligence that was science fiction a generation ago, lends credence to the notion that a few more generations would find Vinges' singularity to be real, and inevitable. In short, 'why willingly choose'? Because cultural evolution may make it inevitable. [Answer] Because it would be the ultimate joining of beings. For us, it would be 'beyond intimate', which for some might be a higher goal. Think of it like enlightenment (in a StarGate-type of sense) where your individual isn't lost, but you are not separate from a larger being either. There seems to be a general idea that a collective mind would be like a bee hive, where you form a super-organism, and the value of the individual is lost. I think that with a collective mind, you can still be your self but be in direct contact with everyone else. Say there would be a problem that the cluster or collective mind needs to solve, instead of everyone being 'blank' and just contribute to solving the problem and not doing anything else, imagine more like a grade of participation, where you may be busy doing something else, and only have these small ideas that pop in to your mind where you just find parts of a solution or support small threads within a larger problem. It would almost be like having a multiprocessor system where everything is running at a different pace, depending on it's willingness to be involved. This would also solve anything like a 'difference in' or 'levels of' minds since your contribution or 'worth' to such a collective mind would vary anyway. There may also be pro's and con's to this whole joining willingly thing. Say the collective mind gets depressed, or has an annoying song stuck in it's head, that'd be bad for a whole lot of minds. And maybe some parts of the collective are more at ease fully joining the mind and only working for the mind like mind-extroverts since they share it all, while others are more of a mind-introvert, where they do share their experience and what they see and do, but maybe not all the time and maybe not private thoughts. One condition to willingly joining a collective would probably be the ability to leave at any point (but also losing any shared benefits or memories you gained while using shared knowledge). Currently, one might follow the idea that existence is to replicate ones DNA. If a collective mind makes that more possible, it would be a reason to join. If the reason for existence would change, say, to pass on knowledge instead of genes, a shared mind or collective mind would be way more securing that objective than trying to write everything down or telling everyone as a method of sharing and making memories live on. [Answer] Resistance against AI or Borg threat or similar events. So to say, I suggest opposite to immortality, just be able to implement mortal life, instead of disappearing. Collective conciseness could be a comparable force to both threats. It's not necessary 100% time for all involved, and have enough place for personal life as an individual, as someone needs or wish, to some extent, like work - you are free but not totally free from it, and if you do not have one it has some consequences. But as MMORPG shows it's attractive idea by itself, and in that system may be different people, who are 100% involved or not involved at all. This way is easy to attract people to such a system, and if after some time someone decides to not get into, he can leave, and be up himself. I'll in, count on me in that. So many problems could be solved that way, and surviving of our species is 1st priority. Which may actually be a reason to form such structure and join to it. Сollective conciseness isn't a mendicant, which begs to join, or forces to join, but an effective tool to solve problems. ## Clarification * Government does not pay for that system, this is a self-paying system, which existence is accepted by civilization. Like the internet - government not pays for its existence, even it was involved in creation. * Reason to form one, It's not a necessary threat, it may be some possible threat, or not a threat but just some tasks(science as an example), it may be joy, religion, asking Q, answering Q, whatever. The importance of that Reason has to be widely accepted by civilization, as the way of doing. * Some have fear of AI raising, and such system could eliminate possible bad outcome from same beginning, guide development, and actually be such system. Which evolution and development are controlled just by human existence, and be a necessary key for its existence. * Invited some borg friend, they told me - we have to use max energy in the solar system for our self's as humans to live, to implement that. It's like bitcoins, they say, you Have to possess 51+% energy available to rule the system. And if we will be not so efficient in calculations-decision-making like AI, let say 10 times, so we should take and control 91% of energy. * By growing of our population, It may be the only way to keep our knowledge integrity. When we talk about 10 billion, 15, 50, 100 billion - maybe it's not a problem, but when we begin to talk about our max capability's in that system, khm, that much -> 3'307'392'000'000'000'000'000'000'000 <- it may make sense for some unusual for us today solutions, and CC may be reasonable solution at least for part of humanity, like government, 1/10 of population. * It's not necessary to have it to be a matrix style when they all dream one dream which is a rather useless waste of possibilities. Isaac Asimov [Gaia](https://en.wikipedia.org/wiki/Gaia_(Foundation_universe)) suggested actually a more fruitful approach to doing so. Although it looks kinda magically and explained not so well, I'll not bet against technical implementation, which will look very similar to that. [Google knows neural+interface](https://www.google.ru/search?q=neural+interface) , [Darpa works](http://www.gizmag.com/darpa-neural-interface/41434/), [Graphene successfully interfaced with neurons in the brain](http://www.gizmag.com/graphene-electrode-brain-disorders/41591/) <- this is interesting. Pure graphene is promising because it is flexible, non-toxic, and does not impair other cellular activity. ]
[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/251280/edit). Closed last month. [Improve this question](/posts/251280/edit) I have been thinking about a world where there have been incredible advancements in biotechnology. Genetic engineering, advanced bionics and, of course, the long-time human tradition of finding new and innovative ways to kill each other. One of these, is Mechs. Mechs are useful for more than fighting, they're very useful in construction and farming, really anywhere where heavy lifting and long endurance tasks are required and the regular engineering of humans (be it genetic or machined) simply wont cut it. They have even found uses in space applications, like station maintenance or personal short distance transport. Think of them like Fallout power armor, Halo's spartan armor, or Javelins from Anthem, pictured below. [![Javelin From Anthem](https://i.stack.imgur.com/if2iG.png)](https://i.stack.imgur.com/if2iG.png) Of course, these kinds of tools are very useful with military applications. Mostly mercenaries who want to take on very risky and expensive contracts and missions and have the money to be fitted like a walking tank, but they have a lot of use cases in professional militaries too. There is a massive problem with them, however. There is a strange medical condition that affects users of these mechs that seemingly has no root cause and is not at all understood. It tends to happen with more advanced mechs with more systems (such as more weapons and active defence systems) Its a condition where people in the mechs start to believe they ARE the mech and are not humans driving them, believing themselves to be sentient AI or something. Users are nearly always incredibly paranoid about being disassembled or tampered with, and will usually fight anyone attempting to remove them from the mech or even get close due to the fear of being EMP'd or sneakily opened up. The condition is treatable simply by removing the person in the mech (simply might not be the best word for it, as they will be actively resisting this), and has no side effects after the fact other than being shaken up and potentially injured from the fight to remove them from the mech. Currently IRL we have a lot of terms to describe all kinds of psychological issues. This would probably be called a "Persecutory delusional disorder" (people with this disorder IRL believe someone is attempting to harm them) but how would we specify that it is both acute and caused by using a mech? What would the most medically accurate term be for describing this condition? [Answer] While I do support Monty Wild's clean and concise solution, I do want to suggest a catchy title: Mechanophrenia, or to have the mind of a machine, could be the term used for those humans who believe themselves to be integrated parts of their tech. Note the Greek roots - mekhane from 'engine' and phrenia from phrḗn, 'mind'. You won't miss the connection from another disorder popularized from media - schizophrenia. In fact it could well be that whoever named this new disorder explicitly wanted to quote on something already studied by the medical community. This double link might also be used to explain how those affected seem to ignore some basic fact about their biology - e.g. the need for sleep, food, and other nasty biological imperatives. Edit: Integrated AlexP's suggestion and switched to mechanophrenia from mechaphrenia. [Answer] Trivially, this is termed a [Delusional Disorder](https://en.wikipedia.org/wiki/Delusional_disorder). Medical terminology has no allowance for making catchy titles for these disorders, even if they become common. However, disorders may also be named after the individual who first described them as something unique or becoming common. If this disorder can be shown to be something other than a common delusion, perhaps caused by use of a brain-machine interface, it may attract such a name. For example, if I was to describe such a disorder and link it to the use of mecha, it may become known as Wild's Syndrome or Wild's Disorder or something of the sort. If I was being modest (which doctors describing such things rarely are), I might call it a Mechanical Identity Delusion. Obviously, your setting's history and personalities will differ, and you'd have to pick a name yourself. [Answer] This would seem to be allied to Prothesis Embodiment. This is the mental process whereby someone who has (say) lost a limb, coordinates themselves with a prosthetic limb. When they wake, they may feel sensations in the missing limb. The prosthesis feels like a foreign object. But with practice, the wearer can add the prosthesis to their self-image: they can move a think as though the prosthetic is part of them. The same occurs to some extent if you drive a car. To begin with you handle the controls consciously. Later, many of the parts of driving are moved to the unconscious: the car is in effect acting as a large prosthetic. If they drove into another car, they might say "I hit them!" rather than "My car hit their car". The same embodiment happens when you become good at a musical instrument. It is possible for someone to think they have left their own body. People with Cotard's syndrome believe they are 'dead' or 'empty'. They can even try to commit suicide, feeling that this would somehow 'put things right'. It would be reasonable to extend this to someone who drives a titanic mechanical body to think they have left their own body and become the machine. The person without the machine is 'dead'. I think some of the Warhammer Titan short stories deal with this sort of thing. ]
[Question] [ A person is placed into the middle of a forest on an alien planet. The planet is to be considered Earth equivalent in all respects (mass, size, atmospheric pressure, etc.) except atmospheric composition: with only trace levels of oxygen - meaning they would asphyxiate almost anywhere else on the planet. Is it realistic that being within this forest, that they could survive? [Answer] Only if this forest is located in a "bowl" with low winds Our common deciduous trees are actually poor net producers of oxygen. By different estimates, it may take about an acre of trees to produce enough oxygen for one person to breathe. Tropical rainforest is a better oxygen producer, however the real question here is not how much oxygen is produced but how concentrated this oxygen can get. A human needs at least 16% of oxygen (at 1 atm pressure), anything lower would lead to asphyxiation. Unfortunately, in real world gases are very quick to diffuse and mix with the rest of the atmosphere. Carbon dioxide, for example, is being released under many processes, and still its concentration quickly drops to minuscule 0.04%. One has to be locked in a room to see this concentration rise noticeably, and it takes unusual (though not impossible) circumstances for this concentration to exceed 16%. Thus, this forest has to be somehow enclosed so the oxygen can be kept trapped. Obviously, we can't keep photosynthesizing forest in a cave, and next plausible geological formation is a bowl - a deep depression or a valley, which must be isolated from winds. In such a valley, gases like oxygen can accumulate to high concentration, creating possibly breathable atmosphere. Alas, this oasis would exist only until the first storm. A storm would blow away oxygen completely, and it will take trees years to build breathable atmosphere once again. [Answer] Alien forest? [![oxygen bubbles](https://i.stack.imgur.com/jEmft.jpg)](https://i.stack.imgur.com/jEmft.jpg) <https://www.botanyunbound.com/post/ocean-photosynthesis-what-a-plant-hears-discovery-drones-and-the-coolest-plant-on-earth> An Earth forest lets its oxygen diffuse away. But you are not obliged to use earth plants. You can make your alien forest be what you need it to be. What if this was a thick CO2 / NO2 atmosphere, or underwater? Maybe your plants make and trap oxygen bubbles like these algae? Maybe the forest plants cooperate to keep these oxygen bubbles within the forest for their own use. Your character could survive within one of these. [Answer] Not only would the oxygen diffuse away, the forest would die. Trees photosynthesize complex organic molecules from sunlight, water, and carbon dioxide, but they also metabolize the molecules with oxygen to sustain their lives. A mature forest, without new growth that is creating molecules to make itself, is not a net creator of oxygen, but that's a footnote. The important thing is that even a quickly growing forest would lose all the oxygen it created to the atmosphere without it, and die. [Answer] I am afraid it is totally impossible. The diffusion coefficient of oxygen in air (in your case it will be in pure nitrogen but it should be practically the same) is 0.2cm²/s to 0.3cm²/s depending on the [temperature and the humidity](http://compost.css.cornell.edu/oxygen/oxygen.diff.air.html). The molar density of oxygen at standard pressure is `22.4 L/mol` This means that 1 liter of pure oxygen at STP contains 0.045 mol of oxygen so 1 cubic centimeter will contain 0.000045 mol. At 20% concentration, this will be `0.000045 * 0.2 = 0.000009 mol.` From [Flick's first law of diffusion](https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Kinetics/09%3A_Diffusion#:%7E:text=J%20is%20the%20flux%20and,%E2%80%8B%2D2%20s%2D1.&text=c%20is%20the%20concentration%20of,with%20units%20molecules%20m%2D3.): `J = D (dc / dx)` If we take a sphere around your forest, let it be 1km x 1km wide, we get a contact surface of a semi-sphere, so `6.28km²` or `6280000000000000.00 cm²`. If the molar gradient across this sphere is `0.000009` - 20% inside it and close to 0% outside, the molar flux across it will be: `6280000000000000 * 0.000009 / 10000 = 5652000 mol of oxygen = 56520000.32 g/mol = 1.8 t` every single second. Can a `1km x 1km` forest product 1.8086t of oxygen per second? One tree produces about 4g of oxygen per second. You should probably double-check everything, because I went through a few orders of magnitudes errors. If someone is in the mood for solving differential equations, he could probably calculate the amount of oxygen that will be available right in the center of the forest (it is a gradient after all) given a rate of oxygen production. [Answer] Perhaps. I figure that since you've pretty remarkable trees to begin with if they can survive at night time (assuming they need oxygen at all), then you can make-up your own rules to an extent. These are the rules you need to play by:* The O2 levels would be ideal at 17-35%, no trouble breathing or with oxygen toxicity. If they go above 35% or so, then clothing will become dangerous, one static spark and you're on fire. So strip. If they go above 40%, then the oxygen becomes increasingly toxic, your body will age fast as oxidisation occurs within tissues. In the graph below, you'll see that normal atmospheric pressure at sea level is at the top: [![Graph of oxygen toxicity.](https://i.stack.imgur.com/ZUE0B.png)](https://i.stack.imgur.com/ZUE0B.png) Dusk would be a danger time, as the photosynthesis tails off, the O2 will start to reduce. The time for unconsciousness would be around 12% (unless acclimatised as a mountain climber), death would occur at 6%. [Answer] It would be perfectly possible for the forest to have the only sufficient concentration of oxygen on the planet - if the forest was at the bottom of the deepest canyon or trench on the planet, and if the other regions of the planet had a little less oxygen than could support human life. And possibly the forest will eventually - which might be many millions of years - provide enough surplus oxygen for higher elevations of the planet to have sufficient oxygen. The lower the elevation the higher the pressure of the atmosphere. But a habitable planet would have to have large bodies or water, so it is actually "the lower the elevation above local water level, the higher the atmosphereic pressure". The higher the elevation, the lower the density of the atmosphere. On Earth, people who go to much higher elevations than they are used to get altitude sickness, finding it hard to breathe the much thinner air. (And people who go to much lower altitudes than they are used to can suffer reverse altitude sickness trying to breathe the thicker air.) Above about 8,000 meters altitude the air is so thin that mountaineers have to used bottled oxygen, and many still suffer serious altitude sickness in that "death zone". So you want a planet with an atmosphere thin enough that it has "death zone" thin air all over the surface, except in one very deep region where the air is thick enough. So you want to check Habitable Planets for Man, Stephen H. Dole, 1964, for the atmospheric requirements of humans. [https://www.rand.org/content/dam/rand/pubs/commercial\_books/2007/RAND\_CB179-1.pdf] [1](https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf) Dole discusses atmospheric requirements on pages 13 to 19, and in table 4 on page 21. The oxygen requirement is oxygen pressure between 60 and 400 millimeters of mercury. So possibly there is a low, low, lowland region with an inland sea with many oxygen producing plants, with a forest of oxygen producing trees surrounding the inland sea, and an atmomsophere dense enough to have about 70 mm of mercury of oxygen at the level of the inland sea and the forest. And most of the planet is high enough above that level to have half the atmospheric pressure of all atmospheric gases, making the atmospheric pressure of oxygen about 35 mm of mercury. And there are tall mountains and high plateaus on the planet where the atmosphere is half an dense as on most of the planet. Thus in those high places the pressure of oxygen would be only about 17.5 mm of mercury. There may be oxygen producing photosynthasizing plants over most of the planet's surface, but the oxygen they produce doesn't stay local but diffuses all over the planet's surface, so there is equal oxygen whereever the altitude is the same. And only the depression with your forest has a low enough altitude to have concentrated enough oxygen in the atmosphere. Everywhere else on the planet the oxygen pressure is about as low as in the "death zone" on Earth, except that the air is really thin in the high mountains and plateaus. There was a somewhat similar question asked a while ago. [Walking to space](https://worldbuilding.stackexchange.com/questions/213913/walking-to-space) fortunately you do not need as strong a pressure differential on your world. [Answer] Without knowing the size of the forest weather conditions etc. I'd still have to say no. Any single mass of vegetation unless a great amount of time passes wouldnt be able to sustain the needed mix of breathable atmosphear without it dispersing to the rest of the planet. [Answer] It depends the size of planet, forest area cover, how much the forest covers can produce oxygen and the consumption of oxygen on that planet. This is the simplest and shortest [Answer] A greenhouse-like setup may be viable - it is up to you to make it natural or artificial. The key point is to limit the diffusion of the oxygen out and other unpleasant gases (e.g. carbon dioxide) in. Be aware that 1% carbon dioxide at our pressure can be survivable for a human, but is deadly for most of our modern plants. It is way too acidic. They are adapted to like pre-anthropocene 0.03% and today's 0.04% already make some of them suffer. As other answers pointed out, plants also do need oxygen for the night. ]
[Question] [ Most planetary rings are rich in water in the form of ice, especially now we are running low on freshwater reserves on Earth. Imagine someone discovered a huge chunk of meteorite consisting of a whopping 100 million carats and decided to auction it and then use the funds to mine the Saturn's planetary ring by hook or by crook, hellbent, relentless... Set in the immediate future everybody raced to space once again. What would be a good non-political reason that can stop all kinds of mining of the planetary rings just within the solar system? We have volunteers, cash, [Alibaba](https://en.wikipedia.org/wiki/Alibaba_Group)... so why not? [Answer] Two reasons 1. Cost - it's not going to be cheaper to mine water in space. There's a massive energy cost to get something into space against Earth's gravity well, and if you're going to mine something like water, there are cheaper ways of getting it - like purifying salt water. Especially because asteroids only come in one size - bulk. If you've got need for all that iron - great! But if you don't, then it's just cheaper to mine the stuff where you don't need to fight gravity. 2. Time - it takes a while to get asteroids from the rings of Saturn to Earth. Cheaper if you decide to spend more money on more fuel, but even still you could be looking at a turnaround time of decades, maybe even longer. And there's no guarantee that it's safe - accidents happen, which means even if you're promised five times your initial investment, that's going to take decades until you see the money and it's going to be a risk. Compare that to, say, a [CD](https://www.investopedia.com/terms/c/certificateofdeposit.asp), and you'll see that people may want to make safe investments. [Answer] The only reason we would mine the rings is to bring water to solar system parts without water. That would NOT be Earth. We might go there for Mars or the Moon or fueling space colonies, but not for Earth. Earth has an abundance of fresh water. And we have continuously improving tech for filtration and desalination. It isn’t worth the space trip. Isaac Asimov once wrote a short story about just how absurd the amount of water Earth has compared to human usage of the water. The story is called [The Martian Way](https://en.wikipedia.org/wiki/The_Martian_Way). It does a great job giving examples of just how much water Earth has for us if we just move it around. You can read about it on Wikipedia... I’m sure the actual text is archived somewhere. [Answer] Would it be easier to mine rings, or to mine the icy bodies that feed them? How about icy asteroids, comets, or craters on the moon? Then there's the PR element. Which would be more likely to receive a huge public outcry against it: picking up ice from the dark side of the Moon and random asteroids nobody can see, or mining those rings that so many people find beautiful? Yes, the rings wrap around planets bigger than Earth, and it would therefore take a great deal of time and effort to put a dent into them, but it's somehow much easier to see a campaign to get ring-mining regulated in the name of "protecting the heritage of all mankind" or somesuch succeeding, compared to declaring a hidden crater with some ice to be an International Park. Things change greatly if you have other things going on in space. As many have said, mining rings for water on Earth is a waste of money and effort, when you could just use desalination or other tricks to isolate not-so-fresh water closer to home. If you have space-mining operations or colonies already, ring-mining seems slightly less pointless, but at the same time, regulating ring-mining for PR reasons also seems more likely. Especially if someone already set up ice-miners on icy asteroids or moons. [Answer] Because it is DANGEROUS. Space travel is full of hazards, micrometeorites can wreck a ship.[![Like this](https://i.stack.imgur.com/WeVVH.png)](https://i.stack.imgur.com/WeVVH.png) The asteroid belt is full of tiny stones milling about. Each one can make fatal impacts on the ship hull. By God's sake, a flack of PAINT shattered the windshield on a mission! Now the asteroid belt is full of amorphous bodies, with ice and frozen gasses that will be ejected once you extract them. Lose a couple of ships to horrific accidents and the cost the just not worth it. [Answer] A dire prophecy predicting doom and destruction might work. Many people would not believe in the prophecy unless otherworldly beings appear, as predicted. That might create a powerful social force for ending the extraction of resources from the planetary rings. [Answer] In general, bulk commodities like water, fuel, food, or most minerals are terrible candidates for space production (rings or elsewhere) or for any other kind of interplanetary commerce. I used to have the intuition that, once things are "in space", it's easy to move them from place to place since they are in a low gravity environment. So you could acquire water ice out by Saturn, then gently send it on a slow orbit to Earth, and use Earth's atmosphere to slow it down for a gentle landing. But, in fact, it takes a pretty significant acceleration to get something out of Saturn's orbit and into an orbit that will reach the Earth. Once it reaches Earth, it will be going at Earth's escape velocity and will require a significant heat shield to survive reentry, and the heat shield would need to be launched back to Saturn. You end up using fuel that is a sizable fraction of the material you are trying to transport. ]
[Question] [ In a time period with medieval technology, what would be the most important local resources? I've put together a small list and broken it down into categories, but I'd like to know if there's anything major I've missed. Sustenance: * Fresh water * Wild game * Fish Minerals (Mines) * Coal * Iron * Tin * Salt * Copper * Lead * Gold, Silver, and Gems Minerals (Quarries) * Sandstone * Limestone * Marble * Granite Natural resources * Wood For what it's worth, I'm putting together a medieval world generator. Image below. [![screenshot](https://i.stack.imgur.com/g71DW.png)](https://i.stack.imgur.com/g71DW.png) [source](https://github.com/olinkirkland/map) [Answer] In roughly descending order for a non-hunter/gatherer culture (remembering that 'medieval' doesn't just mean 'northern European': 1. Arable land/water/pasture 2. Shelter/survivable temperature/resources for clothes 3. Salt/food preservative/preservative spices (good foraging might go here too) 4. Suitable domesticated animals 5. Wood/mudbricks/wattle and daub/other simple construction material (can be replaced with hides from domesticated animals) 6. Something for cordage 7. Medicinal plants (if you have some, and perhaps I'm overblowing their importance, but a lot of people get sick in pre-modern cultures) 8. Perhaps metals/other materials for tool-making here? If they can refine iron that's pretty ubiquitous. If they need bronze then the location of tin mines would be important. And although having something for tools is vitally important (bone, stone etc.), it's generally quite readily available. 9. Defensibility (having big ol' mountains or raging rivers between you and the head-hunting barbarians next door is pretty valuable in a location) 10. Stone for building (not really that important. Pretty much the entirety of anglo-saxon Britain was built from wood). 11. Precious metals/non-preservative spices/other high value luxury goods (way down the list, given that you need a fair bit of the stuff above before you can start to make use of your precious metals). I've very open to additions/repositioning, but it's a start :) [Answer] ## Flax Flax is a plant that was often farmed in Medieval and Pre-Medieval societies around the world. It was an important resource to many societies for several reasons: Food Firstly, its seeds can be turned into a meal or used for linseed oil, a finishing used on wood to protect it from weathering or it can be injested as it too can be edible. The meal produced can be eaten, used as feed for livestock or ground into flour to make bread. Linen Perhaps the most useful use of flax was to create linen, a textile. This could be used to make clothing, bedding and pratically anything that cotton can make, flax can make too. A huge feature of linen though is its ability to produce extremely protective armour. By layering pieces of linen, you can create a gambeson, a type of armour used by both rich and poor for its protective value. String Because flax is string. Flax is used to make string, even today, by twisting the fibres of the plant together. As you can imagine, string is highly useful for temporarily holding things together. You can also keep twisting the fibres together until you get rope, which can be even more useful if you need larger, heavier objects holding in place, such as a ship or drawbridge. Other Uses The same fibres used to make string can instead be used to make canvas, slightly less useful but can be highly valuable with paint on them. It can also be used to make paper, flooring, inks, paints or just be grown as a decorative plant. Supposedly its specific epithet, usitatissum, means “most useful”. The plant has been cultivated since at least Ancient Egyptian times and has been grown all over Europe and Asia for its numerous uses. [Answer] Most of your list is irrelevant. You need the big three and maybe two more things. The first and last thought in your head has to be FARMS, farming is everything, it is the source that supports everything else in the society and most of your population will be farmers. If it it not used on a farm it will not have much use. Drinkable water arable land A robust supply of lumber Assuming the people bring crops and livestock with them. Everything else is a product of these three things, or incidental and not really required. Ideally there would some clay and iron deposits as well but these tend to exist everywhere that has the above. Of course you also need crops and a livestock but people tend to bring those with them. Farming is the basis of society it supports everything else and the majority of your population will be farmers. Regular rain will be important if people can't farm they are not going to live there. water is self explanatory, rivers and ground-water can supply that. Arable land is the basis for food, hunting occurs but it is not a huge focus of society. Wood is the basis for all technology tools, homes, cooking, all are wood resources, even the charcoal used for metalworking is made from wood. the few things that cannot be made of wood are usually made of clay or a metal usually iron or copper. A naturally occurring plant useful for cordage like hemp or linen may be helpful, but people will farm these plants as well. Some other things would be nice to have but they are by no means necessary, fishable waters, source of salt (either mines or bays), good harbors, limestone, these are nice but my no means necessary. Stone is used when available, but is generally too labor intensive to get much use. If you want to get an idea of what life would be like There is a great BBC series available online called, [the tudor farm](https://www.youtube.com/watch?v=dRj1YYnsBGk) that is about a group of experimental archeologists and historians recreating a Stuart farm and living there for a year. It can give you a great idea of what is really needed for civilization of that time. A later program by the same people is about building a castle using all period techniques, (secrets of the castle) and you will notice that even there the only other resource they use is occasionally lead and chalk. Shapeable stone like granite or sandstone are nice but only really necessary if you want to have stone buildings it is not necessary. you tend to have some source of stone anyway, arable land needs a mineral source to refresh soil which is usually nearby mountains. Tin, coal, precious metals, gems, and marble are more or less useless in such a society, or so hard to use or get that they are only used for expensive showy non-essential uses. They may be used if available but they are by no means necessary. [Answer] Arguably, the most imporant resource was land. Arable land provided a way for the local lords to gain economic power: by providing protection for the local populace in exchange for food and good that they produced. Whilst the food itsef is not likely to make them a fortune, they would not be able to make the money if they and their men were starved half to death constantly. Land was often given to wealth lords or knights by the ruler as a reward for various things. Even non-arable land would have some uses, such as being ideal to build upon as you would not need to worry about losing out on useful, farmable land. You might also be able to house animals on there, assuming you have some way of feeding them. Additionally, hills and mountains would be highly valued for their defensibility. Castles and fortresses were often built on them where possible in order to have a staging point and fortified poition in case of an attack. This also allows for you to defend other resources that you own, such as forrests, quarries, rivers etc. Access to coastlines and large rivers was also extremely important. If you have access to the sea, not only do you have a source of fish for your local population, you can create docks and ports to allow for trade with other regions or even other nations. Alternatively, having sea access meant you could defend your country from invasions via ships, intercepting them before they landed. Alternatively, you could argue that the most important resource was people. Without the backs of labourers, the hands of artisans and the swords of soliders, the lords, and indeed countries, would not be able to gain the wealth and influence that they had and nothing would ever get done. [Answer] Good points all and valid. Civilisations of the past have failed when they outgrew their local resources, usually wood in the limit as it is impractical to transport over large distances. However you show a medieval island that is small if the features that look like mountains are mountains. So the most important requirement is a human gene pool. There are various theories and numbers that are bandied about, but in the end you need to have enough people and enough land to feed them. A small island nation will not survive indefinitely with a fenced population. ]
[Question] [ What factors could skew the sex ratio of an intelligent species, especially a humanoid/human sub-race? For example, say one race has markedly more females born than males, and another race has the opposite, many more males than females. The race is unimportant, whether elves and dwarves, nymphs and goblins, respectively, etc. What would lead to such scenario when births of one sex are so much more common than births of the other, assuming the parents aren't deliberately altering the ratio somehow? [Answer] Disease linked to sex chromosome. Here is how to do achieve this using the chromosomal system humans use. Humans determine sex with chromosomes: males are XY and females XX. There are diseases transmitted on the X chromosomes which mostly affect boys. An example is [chronic granulomatous disease](https://en.wikipedia.org/wiki/Chronic_granulomatous_disease). [![x linked disease](https://i.stack.imgur.com/52129.jpg)](https://i.stack.imgur.com/52129.jpg) <http://disorders.eyes.arizona.edu/disorders/nystagmus-1-congenital-x-linked> If a boy is born with the mutation on his single X chromosome, his immune system will be crippled. A girl, however, has another X which can rescue her immune system with the normal gene. This girl will, however, be a carrier - any boy she conceives will have a 50% chance of getting the X with the mutation. A girl born with 2 X chromosomes both with the mutation will be affected but this implies that her father lived to reproductive age despite having the disease. If you make this a disease that is lethal in utero, the 50% of males conceived who get a bad X will miscarry. So assuming that the ratio is 50/50 normally, this would produce a ratio of 75 females to 25 males; half the males die. --- The converse would be a disease on the X chromosome that involved dose - for example, a mutant gene that made some product that was detrimental in high doses. To make it work the mutant gene product could increase reproductive fitness in moderate doses - the heterozygote state. For example, a gene on the X which led to greater fierceness or wakefulness or strength. Male goblins (XY) who have a mutant X would dominate the smaller goblins, and sire more of the children. The mutant X would spread through the population. Mothers with 1 mutant X would likewise be robust and get more than their share of resources. But if the mother had one mutant X and one normal, and conceived a baby goblin with a mutant X father, any double mutant X female conceived would have too much, and die in utero. The same scenario as the male one above 75% males and 25% females because double mutant X females die. [Sickle cell disease](https://en.wikipedia.org/wiki/Sickle-cell_disease#Genetics) works this way (although is not transmitted on the X chromosome). [![sickle cell genetics diagram](https://i.stack.imgur.com/pxfNV.png)](https://i.stack.imgur.com/pxfNV.png) A heterozygote individual with one mutant sickle cell gene is resistant to malaria and has a reproductive advantage. But 2 sickle cell genes (the homozygote) historically led to death in childhood. The fitness advantage of the heterozygote state outweighed the fitness disadvantage when 25% of offspring from 2 her parents die young - so the gene for sickle cell spread through the population. I am thinking now about the Empress goblin, who is a double mutant x and so much stronger/fiercer than a single mutant x male, and considerably more than a normal goblin. Since before her birth she has been prevented from dying by constant medication that reduces the effect of the double dose X. [Answer] It might seem like chromosomal sex determination would result in a 50/50 sex ratio (at least, at conception--sex-linked differences in survivability may skew that ratio even before birth, as outlined in Will's answer). Nevertheless, the human primary sex ratio (at conception) is just ever so slightly tilted towards females... and then switches by birth, to an excess of approximately 7 males for every 100 hundred females. Since males post-birth have higher mortality rates and lower life expectancies than females, it has long been thought that this difference is an evolutionary response to ensure that the sex ratio around reproductive maturity is close to 50/50. But whatever the reason, it's clear that just having chromosomal sex determination in humans isn't good enough, by itself, to ensure a 50/50 split. Yes, it helps to start there (where other determination systems may not), but there are clearly other mechanisms at play, and there's no reason those mechanisms couldn't force any other arbitrary ratio, if there's a good reason for it. So, you don't need to worry about the underlying fundamental biological sex determination mechanism, or chromosomal structure, or any of that. What you do need to worry about is a) Factors that would provide an evolutionary pressure towards skewed ratios, by whatever biological mechanism; b) Over what sub-population you are measuring the ratio. Do you want skewed ratios over the entire population, regardless of age? Do you want consistently skewed ratios across all age groups? Do you want skewed ratios for some specific age groups? Each of these options may be selected for entirely different reasons! Since the question mentions more males being born vs. females, or vice-versa, I'll presume you don't actually care that much about total population figures, or ratios at other specific ages. In that case, the obvious pressures would be extreme mortality for one gender over the other; if, for example, men die at a much higher rate that women, for innate (e.g., genetic health) or social (e.g., war) reasons, but the species is generally (serially) monogamous, you'd expect to see a lot more boys born. But if, say, women have extremely high rates of mortality in childbirth, you'd expect the opposite--most babies would need to be girls, to make up for the ones who die early. [Answer] China is slanted heavily male because of the One-Child Policy that was in effect for so long. Russia is heavily female because of the shortened lifespan of men, generally attributed to alcoholism. There are so many varieties of ways to create gender-imbalance, it is hard to recommend one without more limits on your problem. For example, the China imbalance affects breeding-age population; the Russia imbalance does not. What you need is some cultural activity that is gender-specific and life-threatening. Something like toxic makeup/tattoo work, or perilous hunting trips, or a fatal rite-of-passage, to list a few examples. Try to identify why the sexes in your society are divided and then identify a dangerous activity that sits on only one side of that divide. [Answer] [Sequential Hermaphroditism](https://en.wikipedia.org/wiki/Sequential_hermaphroditism) is a trait that occurs in many fish, gastropods or plants, by which their sex changes at a certain age, size, or social rank. Protandry means all offspring are born male, but some later become female. For example, a group of [clownfish](https://en.wikipedia.org/wiki/Amphiprioninae) has one female, at the top of the social ladder. When this female dies, the dominant male then changes sex to become female. Protogyny (which is the more common form) is where all offspring are born female, but some later become male. A [California sheephead](https://en.wikipedia.org/wiki/California_sheephead) will change from female to male once it reaches a certain size. So, all offspring of your species are born one gender. At some point in their life, they may reach a trigger condition that causes them to swap to the other gender. The skew then comes from what that trigger is - there are far more adults over 20 than people under 20 in the world. There are far more people at the bottom of the social pyramid than at the top. [Answer] Have chromosome triplets. Where one of three chromosomes being an X chromosome is enough to make a newborn a genetic female but to be a genetic male it needs two of three chromosomes to be Y chromosomes. [Answer] These are great answers, but I was getting a different take on the question. Biology has lots of ways to generate such differences. I am going to look at factors that would put pressures on an entire species to skew without eliminating individuals. * reproductive advantage- the rate limiting step in population growth is how many females you have. I've bred mice, and you need one selected male and dozens of females. I imagine androgynous elves where reproductive rates might be slow and you need to maximize the number of females to repopulate. You could have all of a species born female, and only the rulers transition to male. In certain social fish, if the dominant male dies the alpha female becomes male an takes on the role. * environmental crisis-locusts undergo a radical transformation to environmental deprivation. Envision an orc-like race where bad conditions cause females to give birth to only males, or even hyper-males (think ogre-orcs). The large number of males lead to invasions of nearby territories and the extermination of the local males in favor of the invaders. The stressed orc genes spread & survive. In humans, there are sociology studies suggesting increased percentages of males in a population leads to increased likelihood of wars (this is admittedly actively debated). And there are genetic studies showing human migrations into populated areas where a preexisting population's genes are incorporated into the subsequent population, but the Y chromosomes disappear. Kill all the males and there's no competition. * Obligate parthenogenesis - There are species of reptile where at some point all the males died and only females are left.Evolutionarily there are long-term consequences, but short-term this maximizes the ability to exploit favorable environments by maximizing reproduction. You could require mating with related species to 'catalyze' the process if desired. There could be some kind of genetic transfer (imagine a CRISPR-like arrangement where the child gets a sample of paternal DNA and acquires the same hair/eye color) [Answer] ## The process is already there, you just need the right evolutionary pressures A lot of fancy answers about chromosomes etc overlook the fundamental fact that a species can make or reject sperm in ratios of whatever is needed. An interesting thing about humans for example is that we use hormones to naturally increases/decrease the male to female ratios of births to maintain about a 50:50 split even following things like wars where a lot of men die which should result in severe gender inequalities. A 50:50 split is an important ratio for a species that evolved to take advantage of monogamous relationships because it maximizes your breeding potential; however, this is not the only survival strategy that works. A species that has evolves to have harems of females coupled with a low birth rate per female may naturally produce less males. Another case where you have less males is when a "queen" can super breed. There are genetic advantages to the X chromosome due to extra redundancies that make a mostly female species advantageous when breeding is done only by a select few members of society (like ants or bees). In contrast many species (particularly mammals) tend to have secondary characteristics associated with the Y chromosome which can lead to a physically stronger mostly male population which could also in theory be advantageous when you have a breeding queen scenario. [Answer] # The setting's gods deliberately created them that way. A simple answer is that when the gods of this world were creating it, they decided to create a particular race (or multiple races) with an imbalanced gender ratio. Why they might choose to do so is an open question - maybe they've got an ideological reason to do so like a combative god wanting an all-male race of goblins to continually fight other races to abduct their women for breeding. Maybe they're an ascended mortal from another world and want to give the men of this new world each the harem of women they would've wanted as a mortal man. Maybe they just think it'd be a neat social experiment. Who is going to argue with them over it, aside from perhaps other gods? [Answer] # All you need is a Biological Mechanism to make gender transmissible and an Evolutionary Pressure to cause the skew OR just an Environmental Factor that impacts gender Human males already have an impact on the sex ratio of their children. Some men carry genes that predispose them to daughters or sons - [https://www.sciencedaily.com/releases/2008/12/081211121835.htm.](https://www.sciencedaily.com/releases/2008/12/081211121835.htm) (some men have more X sperm than Y sperm, others more Y than X and some equal amounts). All you need is a reason for one genetic variant to be more advantageous than the other to end up with a large sex ratio skew. Say almost all the men are killed in continual wars, then "Bob" who managed to survive and has a predisoposition to having sons will have loads of grandchildren because all his sons will father many kids because there are so many women available, while "Tim" who survived the war has a predisposition to having daughters none of whom can find husbands so he has no grandchildren to pass his "daughter" genes to. You eventually get a population that skews heavily to producing Y chromosomes, and therefor baby boys. There are many other reasons why sex ratios are likely to skew at birth - though in most species they settle around 50% because anytime there are only a handful of sex "A" they are guaranteed to find mates while sex "B" is not, so sex "A" passes on their genes at a higher frequency including the genes that made them sex "A" - this happens until the ratios even out. You could also have the sex ratios dependent on the environment (for example a lot of reptile species have sex dependent on temperature) maybe there were certain temperatures that the species evolved with (that resulted in 50/50 sex ratios) but now the temperature has shifted so that there are way more males than females. There is already concern that some species may start to struggle due to climate change. [Answer] <https://bigislandbees.com/blogs/bee-blog/14137353-bee-hive-hierarchy-and-activities> Look at bees dude, they have way more females than males. I would assume it has to how specialized the drones are meant for breeding while the females don't actually have to bear any children except for the queen. [Answer] A straightforward mechanism for hominids is that multiple births are much more common for one sex than the other. For instance, if males were (almost) always singles but females were (almost) always twins or triplets, or vice versa, a significant imbalance is inevitable. We know there's a genetic component to multiples, so all you need is a mutation that makes it somehow sex-linked. Or maybe your species originally always had multiples (like armadillos) and the mutation was having singles for one sex. If a society wants more of a given sex, then those who have multiples of that sex (and not of the other) would be prized mates and their mutation would rapidly spread. It just happens in your story that one race prizes male children and the other prizes female children, so you can easily evolve opposite results. This could relate to other differences in their societies. For instance, long-lived elves might prefer fewer females to limit population growth, whereas short-lived orcs might prefer more females so they can continually replace warriors lost in battle. Or maybe the sex imbalance is what caused elves to be peaceful and orcs to be warlike. Cause and effect can be tricky. [Answer] > > What factors could skew the sex ratio of an intelligent species (...) > > > The species as a whole is intelligent, but one of the genders is not. This happens in the real world, for example, with humans. As anedoctal evidence, the ratio of men to women in the cast of Jackass tends to infinity:zero. That is a poor sample group, though, so I did some further research. Statistics show that [for every man that wins a Darwin Award, approximately 0.127 women are similarly awarded](https://www.bmj.com/content/349/bmj.g7094). And this is why there are more women than men alive at any moment - males are more prone to engage in idiotic behaviour, which causes them to die stupidly more often. ]
[Question] [ In that distant future. Technology has greatly advanced to a degree where now people could augment their senses using cybernetic implants connected via the brain. [ Essentially making the use of a computer screen obsolete.] The government is considering on the use of having a national I.D chip implanted into the body. The chip has multiple uses. * Be used as a bank account, Displays currency, finances, items bought, Things owned etc. * Display occupational role in society and economics, If no role. Can also display student in education. * Biological and DNA information * Can be used as a tracking device * Prevent kidnapping or so the individual doesn't plan a criminal act. The Science and practicality behind this concept on powering this device in rural societies can be found [here](https://worldbuilding.stackexchange.com/questions/96333/). Though that's not really the focus of the question, so I'm hand waving it for now. Only problem is: would the use of this chip as a necessity have any benefit for the government and economy in a high tech democratic republican society? At least not abused to a dictatorship 1984 level. Or is it simply just a trope as way of displaying a dystopia? [Answer] # The tech is not the issue, card vs chip = no difference [![enter image description here](https://i.stack.imgur.com/G2pwr.png)](https://i.stack.imgur.com/G2pwr.png) There is no security in obfuscation ([Image Source](https://xkcd.com/1105/), licence CC-BY-NC 2.5) Since cards of all sorts are moving towards contact-less RFID technology anyway, there is little difference between using a chip or a card to [authenticate](https://en.wikipedia.org/wiki/Authentication) your [identity](https://en.wikipedia.org/wiki/Personal_identity), other than that it is much harder to steal the chip, which is an enormous benefit for everyone, citizens, companies and authorities (except identity thieves. Boo. Hoo. Cue the tiny violin quintet). So if you have a premise of a standardized national identity already, then whether you use RFID chips in a loose card or an embedded chip, does not really matter. The technology is not the issue. If anything would be an issue it would be the existence of a national identity system, not how it is implemented. But as reality shows us... # A standardized national identity does not equal dystopia As for people talking about how having a national standardized identity system means instant dystopia and The End of Privacy... I cannot disagree more. In my country Sweden, we have a national identity. The instant you are born, or when you have any kind of permanent residency here, you get a [personal identity number](https://en.wikipedia.org/wiki/Personal_identity_number_(Sweden)). But the fact that you can use that as a key in a database does not mean that all databases can cross-collate their data. In fact, this was one of the first thing that were banned when Sweden as a pioneering country instituted personal data protection legislation. And then there is the simple fact that company A has no reason to let company B or the authorities rummage around in their business data. Also thanks to the early vigilance, there is now a well ingrained opposition among the public and the authorities to any and all kind of registration of political sympathies, affiliations, religion, sexual orientation or any other kind of "sensitive personal data". So curiously enough, after over half a century of having a standardized national personal identity system, Sweden has not fallen into dystopia or a nightmare of personal data harvesting, not any more than anywhere else. # But what if... ? Yeah, what if? What if your government, or a mega-corp, or a criminal syndicates, or a jilted lover suddenly goes off the deep end and decides to start using your national identity to put two and two together and making your life miserable with that? Then we would be much better off if we never had an identity system, right? Right...?! Not really, no. First there is the issue of actually getting databases to play nice together. Once that is up and running, it is not as if you did not have an identity anyway, it is just slightly more fuzzy around the edges. You are not anonymous and you are not safe just because your identity is a little bit obfuscated compared to having a standardized national identity. Because as xkcd teaches us above: there is no security in obfuscation. They will find you anyway. And if you think that you can do the "[I am Spartacus](https://en.wikipedia.org/wiki/Spartacus_(film)#.22I.27m_Spartacus.21.22)" trick and hide in a sea of John Does... sorry, that only works in movies. If there is any kind of uncertainty about which out of a possible few John Does might be the one they want to make their life miserable for, they will not shrug and go "Oh well... guess we better not do anything then"... they will just do it for all of them instead. # A few technical notes "A RFID chip can be read by everyone remotely" No it can not if you make chip standard such that only an valid authentic trigger signal will lead to a response. "If data is on the chip, all data can be stolen by everyone". See the point above. The chip can be made such that only the data that the reader is permitted to read is released. "Yeah but there may be bugs..." Yes. And? There are as many bugs here as the author wants it to be. This means this thing can be more full of bugs than an ant-hill, or have none at all. The author decides. "All technology can be hacked" No, [Magical Hollywood Hacking](http://tvtropes.org/pmwiki/pmwiki.php/Main/HollywoodHacking) only works as well as the author wants it to work. And the fact that sometimes, some things get hacked in real life does not mean Magical Hollywood Hacking is a reality. "With a chip you can never be rid of your identity" See the main post: you cannot get rid of it anyway. And even if you somehow could have shed your identity that makes you a highly suspect character. This is because in a dystopia the mere fact that you have gone off-grid is reason enough to cast suspicion on you according to the — very unethical and twisted — principle of "Only those that have reason to hide will hide". [Answer] Almost by definition, such an implant can be read (and written?) from a distance. Also, read/write would be much more common. I live in a country where all citizens have national ID cards. What does that mean? * The government has a second picture of me on file, in addition to the driver's license. (Of course I could have opted out of having a driver's license by not learning to drive, but that isn't practical in much of the country.) * If I want to identify myself, e.g. to open a bank account or to vote, I use that card instead of reciting my social security or tax number. * As a side benefit, I can use it instead of a passport to visit many countries. * I use the ID card every couple of weeks. I work in a company where all employees carry RFID chips. That chip is on my keychain, not implanted, of course. What does that mean? * It is tracked when my chip opens certain doors. I could ask a co-worker to open the door for me. They'd probably do it. * It is tracked when my chip stands in line in the company canteen. I could also pay cash. * It is tracked when my chip arrives for work in the morning and leaves in the afternoon. I could file a time correction with my boss if that tracking is missing. * I use the chip up to a dozen times each working day. Note how I wrote the second group of bullet points. My chip opens certain doors. There is a presumption that it was used by me, but all the records prove is that my chip (or a good fake) was there. But the key thing, for good or bad, is not the implantation of the chip. It is what you record there, in addition to the ID card data (picture, name, birthdate, residence, citizenship). * Using cash, I could buy donuts every morning instead of milk and cereals, and nobody would know (except for the guy in the donut shop who recognizes the face of a regular customer). If I pay with an implanted chip, it would be clear if I'm living healthy or not. What would that mean for my medical coverage? * Again using cash, I could buy a train ticket and visit another town, without any data traces. I could probably do the same with a car, but somebody (or some system) might track the license plate. If I pay with an implanted ID, that train ticket might be recorded there and it would be clear that I was on the train. As steverino pointed out in his answer, much of that data is already in the hands of Google and the like. So would it be worse if the government had it, too? On the one hand, a government has much more power than any corporation. You don't have to go to Facebook if you don't want to, but you have to file data with the tax office. On the other hand, a good government has much more democratic oversight than any corporation. [Answer] I would suggest that it is entirely possible that given your starting condition, the id chip is completely unnecessary. > > Technology has greatly advanced to a degree where now people could augment their senses using cybernetic implants in their neural own network. > > > In today's world, data science and data mining have already progressed to the point that Google, Amazon, and Facebook are able to link purchases from point of sale devices to web based profiles. If neural networks are that much more extensively used then individual profiles and data signatures to link them, will be considerably better developed. Eyetracking has been studied as a means of gathering more information on user profiles. Cybernetic implants that obviate a monitor mean that the data requested by the user is directly linked to interest rather than determined from indirect means like eye tracking. [Answer] # It is much more... difficult... to steal an implanted chip than a card ``` Hello, may I see you ID please? Sure Pulls severed arm from purse ``` As you can see, an implanted chip would be more secure, as it would be very difficult for a thief to take it off your hands (:D) and implant it into themselves. You would also be able to track your severed arm, in case it was stolen. And people who are trying to verify you won't be worried that you stole someone else's ID. The chip could also disable itself if the arm got cut or if the person died. You could also use the chip for payments. # To monitor vitals In Russia, the Fitbit wears you. The chip can be hooked up to you and have sensors that monitor heart rate, blood sugar, and death. You could monitor your sleep, graph your heart rate, alert you when your blood sugar is too high, or let you know when you die. # Be an interface/ smart watch Kind of like those watches that would project your phone on your skin, except more permanent, and right below the surface of your skin. You could call someone with your hand! (Microphone in pinkie, Speaker in thumb) # Etc With significant technological advancements, just take (almost) any tech and shove it underneath the surface of your skin, and BOOM your arm/whatever has now been upgraded with more useful functionality than what you could have gotten by putting it in a card. [Answer] Rather than explore the dystopian aspects, how about plain old fashioned accidents ? Like many people I've been in situations where some of my credit cards, transit cards, id badges etc have been exposed to a strong enough magnetic field to wipe or corrupt the data. Getting replacement cards is a hassle but at least it's non-invasive. Replacing a wiped chip would require a minor surgical procedure, then there's the problem with what to do with the old one ? Lets say that for practical purposes the best place to implant the chip is in the back of the right hand, for example. A corrupted chip might still be capable of transmitting, albeit garbage, but that transmission is enough to interfere with the replacement chip, so now the old one has to be removed first... I'd be a lot happier if I could replace my credit cards without accumulating scar tissue. Then there's the matter of upgrades. If a security hole was found in the Gen 1.0 chips and a physical upgrade was necessary to close that hole and get to Gen 2.0, how do you that for a population in the hundreds of millions ? It's just not practical. [Answer] Popularly, identity verification has three dimensions - * what you possess (a card, smartphone, or chip), * what you are (fingerprints, retinal scans, facial biometrics, DNA, voice print, behavior), and * what you know (a password, proper entry procedure, etc.) Currently, smartphones and cards are being frequently used for a "what you possess" security components because they are inexpensive, nearly everyone has one, and they are portable. Chips would enhance the portability component by making it harder to lose and more difficult to steal. Technologies like digital tattoos (<https://www.theverge.com/2016/5/5/11597878/skintrack-carnegie-mellon-skin-tracking-smartwatch-userface>) are allowing that same hard-to-lose/difficult-to-steal to extend to networked systems like your smartphone/personal digital assistant. Other technologies like identity secured by blockchain (think bitcoin) make it possible to go chip/smartphone free. As for utility think of all the things to which you (or the government) want controlled access and imagine the chip/smartphone/whatever as that access point. Property records and bank accounts are obvious, but so might be health records, criminal records, proof of citizenship, proof of taxes paid or who returns are due to, proof of paternity/maternity, proof of service (military, police, current employer), proof of eligibility for some benefit (food stamps, social security, health insurance), proof of authorship/ownership [Answer] ### It's a dystopian trope We can use biometrics today to perform the same legitimate task (secure identification) without the invasive implantation (body horror trope). * Carrying your money data on your person-chip means you cannot trust the banks (dystopian trope) * Occupational role stored as data is itself a dystopian trope about class ("Now strip naked and get on the probulator") * Student IDs (and Driving Licenses and Library Cards and Auto Club memberships) implanted is a classic Big Brother trope. An implant cannot be used as a tracking device unless it can receive and send signals at quite long distances. Implanted tracking devices is another classic dystopian trope. Go all the way - instead of implants, use Explosive Collars (another dystopian trope, a bit less subtle) [Answer] The ID chip would likely (in my mind) be a short term transition technology. At the point that a society has traded that level of liberty/individuality/etc for the convenience/safety of chip technology, it would only be a short time before it would be replaced by completely biometric means, finger print, iris, dna, and so on. Tracking is the one benefit of the powered chip over bio, the technology for remotely verifying dna is much further off. [Answer] Any identity-altering related crime we have today would need to creep into medicine. In other words it would probably create a (black?) market for identity-altering surgery replacing the official ID with a hacked/forged one. As any invasive surgery can be dangerous it would create potential health hazards for rebels and criminals. Wow that would make for a creepy sci fi novel. [Answer] Hackers, Uh, Finds a Way Jurassic Park reference ^ You asked if there would be any problems using an ID chip implant rather than a card. You also mentioned augmenting senses using cybernetic implants. Problems I'm on the side of "That's probably a bad idea". Even now in an age where cyber security is improving, nothing is ever safe. Just recently scientists figured out how to use sound waves to control devices. The other day someone hacked their own insulin pump. The other day it was said that hackers almost got into the power grid. Using cybernetic implants the way you mention would only escalate the issue and below I will list all the problems with it... * Hackers can now track people much more efficiently * Identity theft would be much worse with Hackers using someone's DNA data for nefarious purposed * Cybernetic implants that augment senses could be over/under augmented. Imagine a set of high tech hearing aids that let you hear through walls or something in your eyes that improves your vision. What if someone hacked it and maxed it out? Or what if they turned it off? Imagine the problems Benefits It will be harder to lose your ID if it is inside you instead of it being a card. That's about the only good thing. Also maybe even it can monitor if you are having a heart attack or stroke and call the ambulance or stabilize you. ]
[Question] [ Consider the following concept: * Everyone in the world is naturally a hard worker. * Everyone in the world is naturally of equal intelligence. * Everyone in the world receives equal educational opportunities. * Everyone has an equal desire to follow some passion and start a successful business in order to offer that passion to society. To be clear, people want to share their passion with the world in exchange for revenue without the constraints of a boss or bosses. Everyone desires to be the leader of their endeavor, so as to create innovate and share freely, and earn the maximum return on their labors, with no boss above them to share the profits with based on class or rank, since everyone is equally intelligent and educated. I was thinking about a philosophical concept and decided to put a world building twist to it. I've been thinking about the bottom 50% of the world's population in terms of wealth. *If* the above points were all true, everyone could be happy, financially free, successful people, right? All people could work hard, think hard, obtain knowledge, and start successful businesses, and no one would be poor, right? But is that actually true? That's the question I had to ask myself, and I thought such a question could be best answered here. What would a world be like where all of the above points are true and everything outside of those factors is similar to Earth? What challenges would people have to overcome in a world like this? [Answer] There are two points about your post that struck me: 1. You assume, that being smart, motivated, and educated will automatically lead to a succesful business. 2. You assume that everyone having their own business would lead to a good quality of life. --- If you choose an appropriate sampling of people, we can assume that conditions as you describe them allready exist in todays society (e.g. by only looking at people who have started their own business). As such we can assume that the same problems business owners are having today, would still apply (scarcity of resources, production outpacing consumer markets, unequal distribution of wealth leading to market advantages/disadvantages, markets crowding because people want in on a lucrative business...). In shortform: The lack of a guiding force would lead to tension where business interests overlap. Other than that, we would look at a hyper-outsourced world: The positions that would be traditionally filled by employees, would instead be filled with subcontractors as nobody would be willing to be a employee for long. As time went on, these subcontractors would fill smaller and smaller niches, up to a point where they become indistinguishable from regular employees. At first these companies would act largely indipendent, with contracts always beeing handed to the lowest bidder. If you want to know what happens when Companies can hire people on demand, based purely on profits, with no long term binding conditions, have a look at the industrial revolution. Soon politics would intervene, granting protective rights to small (one-man) companies. At this points you have todays society, only with different names. --- To conclude: If you don't change the requirements of the market, no matter what system you choose, you will arrive at very similiar conclusions. [Answer] In Czech language we have term for something which I think would happen. It is called [Švarc systém](https://en.wikipedia.org/wiki/Misclassification_of_employees_as_independent_contractors) and the link goes to english term which boringly says "misclassification of employees as independent contractors" What does "my own business" mean? To someone it means to buy some product cheap, and sell at higher price. To someone it means to create a product and sell it. And to someone it means to offer their services as lawyer, accountant, or IT professional. My personal opinion would be, that not much would change. "Employees" would turn into "contractors" and there would be no standard form of closing employee contract. Also I expect very low level of state regulation. People would deal everything by closing a contract. As next step, I think you should read on [libertarianism](https://en.wikipedia.org/wiki/Libertarianism), which is economical school of thaught to deal with exactly this idea. [Answer] Total breakdown of society as essential services no longer function. Why? For every business there is a right size or size range. A cab driver can be a single, self-employed individual. To run a restaurant, you need at least one waiter and one cook; more are better. A power company or a bank needs hundreds, if not thousands. If all those insist on being self-employed businesspeople, either their independence is a fake (cf Pavel's answer) or the system becomes impossible to manage. [Answer] There's no reason to assume that people with different passions will earn the same amount of money. If there are a few people whose passion is to be dentists and many people whose passion is to be musicians, the dentists are going to earn more money. Society in general would also be poor if value can't created by having big organisations that can produce products through economies of scale. [Answer] There would still be economic differences between different types of businesspeople, and different business types would still require different amounts of initial training and on-going practice. For example, if my desire was to create the best brain surgery business in the world, I'd need to invest in a lot of training for myself (this could be a time investment, assuming that all education opportunities are open to all), in getting contracts with skilled anaesthetists, surgical nurses, operating theatre equipment manufacturers, cleaners, receptionists, and logistics providers (I need blood delivered regularly, therefore I need a reliable transport company, with a reliable storage system, and related maintenance), in getting people to use my brain surgery business (marketing/advertising) and in ensuring that there is post-surgical support for my patients. That's a lot of effort, especially when I can't (due to lack of interest from other people) employ them to do specific jobs. I'd have to pay the best rates, and offer the best standards to keep them, else someone else could come up with a better contract for them. On the other hand, if I want to be a freelance artist, I need some materials, and possibly some way to show off my work, but essentially it's just me. The materials might need third party support, but I could work with found materials (e.g. wood from forests, rubbish, mud) and still do OK if people like my work. In both cases, basic life requirements such as somewhere to live, and food and drink are essentially the same. However, the artist can sell a lot of art works. They are constrained essentially by the number of people they can find who want to buy what they create, and the time it takes to create their works. The price they get for their works doesn't necessarily correspond to the time or material cost. If people like what they create, they can be rich and successful. If people don't, they will be poor and lacking in basics. The brain surgeon can only operate on people who need brain surgery. There are presumably a limited number of these, so this is essentially a low demand occupation, but when you need a brain surgeon, you're willing to pay whatever it takes. The price they get for their work probably starts higher than the artist can handle, but the expenses are a lot more too. If there are lots of people needing brain surgery, they will be rich and successful, but also really busy, so possibly lacking time to enjoy their income. If there are no people requiring their services, they won't be rich. They might even be in debt to people they have contracts with. You would also have some problems in this society. There are some businesses that can't work without multiple people involved, and there are some jobs that don't necessarily result in a direct gain for the worker. An example would be an airline pilot - they can fly the plane themselves, but how would they get a plane in the first place? The initial investment would require contracting with 100s or 1000s of people to build it, then it's totally useless unless you have other people determined to build the best airport business in the world, people determined to drill oil, people determined to refine the oil to fuel, people determined to transport the oil to the airports, people determined to operate air traffic control towers (would you have a contract with each individual? If not, what if you have a contract with Alice, and Bob is controlling the rest of the planes in the airspace you're in?) and so on. [Answer] Most people aren't equally talented in all facets of running/owning a business. For instance,just because someone is a hard worker and motivated, doesn't mean they know how to market themself/their product or understand the necessity of it. Just because I am good at making bread doesn't mean I know how to manage money or talk to people. Some will solve this by contracting with someone else to complete the marketing aspect. The other trick is, does politics and government count as a 'business'? Are judges and teachers also running single person businesses? If so, public servant type positions are going to get much more challenging. Not only will you have to consider a persons qualifications when running for office, you will also have to examine the contract they supply, the price they are willing to do the work for, etc. [Answer] It's not just training and motivation. Bach was not better educated than other composers. He was simply better. No matter how much musical training I received, I still wouldn't be Bach. @Christian [said](https://worldbuilding.stackexchange.com/a/32070/2113): > > If there are a few people whose passion is to be dentists and many people whose passion is to be musicians, the dentists are going to earn more money. > > > But this isn't true. Some of the musicians will make more money than any dentist. This is because there is a maximum number of customers for an individual dentist. There's no limit to the number of customers for a musician's recordings. And some musicians are going to be more popular than others. Some of that can be explained by different levels of passion and training, but not all. And there are also skills involved with running a business that are entirely separate from knowledge. For example, when are you better off refunding a customer's money and when should you tell them to go away? The answer is not to tell them to go away whenever you can get away with it. Some businesses will be preferred to others for these kinds of reasons. And automation definitely won't help here. Automation makes it easier for one business to dominate others. That's why music is so easily dominated. It's heavily automated, where one person with assistance from a relatively small number of people can make a recording that billions could hear. Even live performances can have tens of thousands in the audience. With sufficient automation, you no longer need people to work. The machines could do everything. They'd grow food, prepare it, etc. Some hobbyists might continue to produce art. [Answer] Other than the equal education/intelligence, we have that now in the western world. You just have to ignore what we programmers call the 'syntactical sugar'. In this case, the syntactical sugar of the employer/employee terminology. Employees are, ultimately, independent contractors who can take on new clients (employers) as they see fit. They can take a job, leave a job, demand more money, turn down jobs, etc. Economic reality may put them in a position that they need to take on a client (aka, a job), but that's no different than a major manufacturer needing to take on projects they don't like so they can pay the bills. Even large companies have to agree to abide by terms of contracts they sign. (I often advise professional programmers to look at themselves as contractors who are engaging in fair trade with an employer of skill for money, rather than assuming a subservient position to employers) Now given all that you describe, will everyone be well off? No - because you missed one of the largest factors in an economy's success... the rule of law. If law is arbitrary or corrupt, hard worker or not, the independent contractor may not be able to get ahead. But if the law is fair and just, that combined with the elements you describe will lead to a very wealthy society. You will not get equality in wealth. Some business will do better than others. And some people may have health issues that prevent them from succeeding (mental illness, for example). But you would see a very vibrant economy if everyone had an entrepreneurial instinct and serious work ethic. One last point - Poor is relative. In the US, poor might mean a small apartment in a bad section of town, second hand clothing, and a four year old iPhone. In other parts of the world, 'poor' may mean they have nothing - at all, period. So when you say 'poor', you need to define better what you mean by it. ]
[Question] [ So, we have a captured planet/moon orbiting a gas giant in the habitable zone. It is akin to prehistoric Mars, its geological activity having been maintained by constant tidal flexing from the gas giant. It is half the mass of earth, but knowing that the volume of a planet affects its surface gravity, could it still experience surface gravity of 1 g? [Answer] Yes. Surface gravity depends on the mass of the planet and its radius, according to the formula $g=Gm/r^2$. If you put half the mass of Earth in $1/\sqrt{2}$ of its radius, the surface gravity will be the same. Of course this would alter the density of the planet significantly, needing complete different materials to make it possible. The average density would increase by a factor $\sqrt{2}$, which is not out of the realm of physics: 7.7 $kg/dm^3$ is a bit less than the density of iron. [Answer] L.Dutch's answer gives you the basic idea. At half the mass with a surface gravity of approximately Earth normal your planet has a radius of $2^{-1/2}$, a volume of $2^{-3/2}$ (0.35356) and a density of $(2^{-1/2+3/2}) = 2^{1/2}$... all as multiples of Earth's values. Since Earth has a density of approximately $5.495\ kg/L$ your planet clocks in at around $7.772\ kg/L$. That's a bit higher, but not unachievable. Lots of comments about increasing the core size or density, but I think that's a non-starter. Earth's core accounts for only about $1/60$ of our mass, so your planet's core would have to be much larger by comparison and significantly more dense than our iron/nickel core to make much difference. The big payoff comes further up. A little over 70% of the Earth's mass is in the Mantle, and the second most abundant element in there is magnesium. That's pretty wasteful considering that magnesium is a very light material. If we were able to removal all of the magnesium and replace it with more iron, the average density of our planet would increase quite a bit. What if we replaced most of the magnesium with manganese which is more than 4 times heavier by volume? OK the compounds aren't quite as much higher in density (some are lower, but we'll ignore those) so perhaps not. But you could simply siphon off all of those magnesium compounds to sell on the galactic gem market. I'd say that simply changing the composition of the mantle can do most of what you need. Increase the iron in the mantle, add some more nickel in there too. Liberally sprinkle the crust with deposits of heavy metals. Maybe write in a collision with a heavy element asteroid in the planet's history - it's always fun to find new sources of Iridium for example. ]
[Question] [ A member of a species becomes immortal, loss of senescence, incapable of dying from age-related issues. Otherwise it remains the same as other members of its species at the point at which it became immortal, including its current genome/dna and instinctual needs to find mates and reproduce. Would such an individual stagnate the evolutionary march of its species? [Answer] An immortal could certainly have an impact on the gene pool if they lived long enough and had enough descendants. Genghis Khan, who lived between the 1100s and 1200s, is believed to be the ancestor of roughly about 16 million men in the modern-day, and he only lived to be about 60 or 70. I'm certain that, with enough partners, a person could easily share their genes with the whole of a planet, even one with billions of people like Earth. It might take hundreds or even thousands of years, but it would happen. It is exponential growth. The immortal has children and those children have children, who then have children in turn. Unless the descendants all have short life spans, this process would be faster than you would expect, especially if the immortal is purposefully trying to have as many as possible. The biggest problem is what happens when there's overlap. If everyone is a descendant of this immortal, you run into the issue of inbreeding. It would be subtle at first, but damaging after enough time. I suspect a world like this would eventually run into the problem many royal bloodlines faced by trying to breed only within their own group. If everyone has the genes of the original immortal, then every time the immortal contributes again they make things more complicated. I don't even want to imagine what a mess genes would be if the immortal repeatedly had children with its own descendants. As I said, it would probably be similar to old royal bloodlines which suffered from issues such as serious birth defects and other diseases. It might take 10000 years before the effects are noticeable, but it would certainly happen. If immortality is a shared trait, then things are even worse. You have the same problem multiplied exponentially. Mortals would be crowded out almost instantaneously, unable to compete with their immortal counterparts. Then those immortals would have more children. Familial lines would crisscross and zigzag in a chaotic assortment until the descendant's DNA becomes a tangled mess. Then the messy genes of descendants would get contributed back to the gene pool to make things worse. Honestly, I can't see any situations where this goes well. The immortal should try to have as few children as possible. [Answer] The answer to this question depends upon a number of factors: 1. The population of the species. With a small population, the immortal individual makes up a larger fraction of the gene pool than if the population is large, and therefore it has a greater influence upon the genetic makeup of future generations. 2. Whether the immortal individual can die from environmental hazards. If the immortal individual may die from other causes, then its death from those causes would remove its influence from subsequent generations. 3. If the immortal individual is seen as a fitter mate by the opposite sex due to age, experience and youthful appearance. If the immortal individual is selected as a better mate than mortal individuals, then it will have a greater effect upon future generations. However, it seems likely that unless the population is very low, while the immortal individual may have a relatively large influence upon the gene pool, it won't be able to contribute more than a single percentage point toward the next generation, which may slightly retard evolution, but wouldn't make it stagnate. Eventually the point may come where the immortal individual is sufficiently different to the population that it will no longer be able to reproduce successfully, at which point it will cease to influence the evolution of the species. [Answer] # Try playing with a population genetics simulation [This simulation](http://virtualbiologylab.org/ModelsHTML5/PopGenFishbowl/PopGenFishbowl.html) is pretty and very intuitive, working with red and white fish. Your immortal counts as a "migration rate" (except in his case, all the migrants are the same fish). If you set the simulation to a minimum migration rate (0.1) of fish of a different color, in a few hundred generations they take over the pond. If, however, they have a fitness penalty (set Rr to 0.9 and either rr or RR - whichever migrant color you picked - as 0.8) then about 1/3 of the original color will continue in the population. Now both those numbers are very, very high, but you are probably interested in time periods a thousand times longer, which (very crudely) implies numbers a thousand times less might work. Even so -- depending on the size of your population, your immortal may very well not be able to make a dent in it simply based on the numbers. And if there really has been favorable evolution going on in the rest of the population, his offspring will start to be selected out. [assortative mating in this simulation seems to have a bug, sorry] Of course, there is a wrinkle not present in the fish simulation, which are that the immortal's offspring really are all related to each other and could carry many different recessive genes. If they directly breed with one another, they could suffer immediate problems that would keep them from taking over. Or they may just not want to! In which case it's going to take more than a toy HTML5 simulation to figure out the problem. :) [Answer] No. The evolutionary process -- offspring adapting randomly and the ones with beneficial mutations surviving more often to pass on those mutations -- is not damaged by the existence of one immortal member. What happens is the rest of the species breeds and evolves as normal, and the immortal stays the same through the generations. If the species evolves too much they no longer resemble the immortal member, and might not even be able to interbreed with them. [Answer] Yes absolutely. IF the trait is passed down genetically. The extent of the stagnation would depend on how many of the offspring of the immortal themselves become immortal. If the answer is zero, then the stagnation will be virtually undetectable , even under deep investigation. Using human reproduction rates, and relatively normal sexual behavior from the immortal, we can expect less than one offspring per year if it is male, and less than one per 3 years if female. After 10000 years, well under 1 percent of the human race will be genetically related to the immortal. Under 1/10th of a percent if the immortal is female. And this is for any relation, even 9999th cousin 9999 removed. ==== Of course, if even 1 in 10 of the immortal's offspring is also immortal, then after 10000 years the species will be 90%+ immortal, and 99.many-nines% related to the original. [Answer] ### Very little One immortal, permanently fertile individual is genetically equivalent to a long line of heavily inbred relatives, without personally experiencing signs of inbreeding. Families that breed repeatedly with the immortal across generations may experience decreased genetic variability which in turn would probably be selected against due to recessive traits being exposed. If the immortal is somehow super-desirable, or the population very small, the overall effect would be similar to a genetic bottleneck, but it would have to be a pretty unusual situation requiring other restrictions to keep it in place (e.g. lack of influx of new genetic material from the outside of the group). ### Important caveats * Immortal and permanently fertile are not the same. The human ovary, for example, performs all meiosis during embryonic development, and can make no more eggs after birth. So if your immortal is a human or humanoid woman (or other ovary-bearing gender applicable to your setting), she will have as many eggs as she was born with, and the immortalisation process won't change this. So she could have, at best, a relatively large number of children but not a continuous output across the ages. * Loss of senescence does not mean loss of genetic variation. Gametes work quite differently from somatic cells in the way they generate and, in controlled ways, encourage genetic variation. So, although the somatic cells of the immortal will be unchanged over time, each new meiosis will still produce a unique combination of alleles through recombination, and new mutations could appear through all sorts of mechanisms like defective transcription/recombination and DNA damage (if these mechanisms are not also modified by the immortalisation event). Quite a few genetic defects that we know of appear de novo, meaning neither parent had it. * Psychological aspects: if the immortality trait is not inherited, the immortal will have to watch all their children age and die. I can definitely see this putting you off having children in the long run, or at least space them out quite widely. If immortality is inherited, this is an entirely different can of worms, see [PcMan's answer](https://worldbuilding.stackexchange.com/a/217419) * Social aspects: is the immortal open about their status, or do they have to hide their immortality? If the former, then people would know that this surprisingly youthful looking person is in fact their grandfather and you really shouldn't have kids with your close relatives, no matter how incongruously hot and young they look. If they hide their immortality, chances are that they would not be able to keep up the charade in the small and isolated community where their genetic impact would be meaningful. [Answer] First of all, the phrasing "evolutionary march" implies that evolution is a goal-oriented process, which it is not. Evolution does involve random drift, and removing old individuals does reduce that. But to the extent that there is a consistent "fitness", removing an individual just because it's old doesn't help that. Why would it? Why would an old individual dying make for better fitness than a young one dying? Evolution works by death being based on genes. Individuals dying from something other than their genes, such as age, doesn't help fitness. There is no "planned obsolescence" in evolution. If the individual has genes that are "more fit", then it staying around improves the average fitness of the species. If it has less fitness, then it will be outcompeted, and the fact that it's not being killed by old age won't stop that. [Answer] TL;DR: There will be some, but it will depend a lot on the initial situation. MWoT Answer: Your ageless immortal is merely ageless. While that might eliminate some diseases that are caused by old age, it may not eliminate diseases by outside factors, nor will it prevent accidents, illness, and predation from taking their life. And make no mistake, something will kill them eventually. We living things might be survival of the fittest in an individual sense, but evolution is all about survival of the good enough. It's about random mutations showing up and seeing if they breed true and help the species. As a side note, I am making no assumptions as to species -- this should hold for anything from aardvarks to zebras. We, of course, are filed under H for human. ### Initial Impact The initial impact will depend on a few factors * Gender -- A female can only have one set of children at a time while a male can impregnate multiple females at a time * Initial population -- Them being 1 out of 100 individuals will have more of an impact than being 1 in 1,000,000. * Heritability -- How easy is it to inherit all or part of this individual's immortality * Environment -- How likely is this individual to die of non-aging related disease/illness, accident, or predation? The inheritance mechanics will be the largest factor in this set. As stated, if everyone descended from this one individual gains the full immortality, then it will eventually become the dominant trait I would think. What effect that has will certainly be based on what the species in. Immortal bunnies will have a different impact than immortal humans or wolves. Remember, they can still starve to death should their numbers exceed their environment's capacity to support them and they cannot relocate to an area that can support them. Inversely, if they don't inherit anything outwardly, then they aren't getting anything interesting unless another random mutation or atavism down the progenitor's line makes another individual immortal. In which case, the whole process starts again. Another possibility is that inheriting part of the immortal's genes gives them part of the benefit, but not the whole package. Some might be immune to age-related diseases, while other gain an increased theoretical lifespan though little defense against age-related diseases. Breeding between the lineages might wind up with another fully immortal member of the species to again propagate the gifts to. ### Future Impacts As time goes on, your immortal will still have the urge to reproduce (as per the question) and will likely do so, either continuously siring children or having them. This means their presence in the gene pool will always be topped up, so to speak. This could definitely impact the diversity of the species. The impact will depend on how much the immortal's species manages to avoid inbreeding, especially close inbreeding. But another thing your immortal has is experience. If they can teach their descendants, immediate or otherwise, a portion of their experience and knowledge, that will potentially give those youngsters an advantage in their life. * For a prey species, that could be ways to avoid predators better. * A predator species could hone its hunting tactics over the decades/centuries and pass those skills down. * For humans or other similarly intelligent species, that could be more in life hacks, connections or money. * Your immortal will also know the best ways to get a mate so should have no trouble reproducing should they want to -- another thing they can pass on if they desire their bloodline to continue. What this could lead to is others trying to get the immortal to accept their children, even if they aren't the immortal's themselves. Depending on the intelligence of the species, this could lead to the immortal procreating less by being a surrogate parent for other's children, not like how aunts/uncles or grandparents can fulfill the role for us. ### Intelligence Factors These immortal's cells do not age out so in theory, they could be cultivated forever. With an appropriate sample kept, cell samples could be continuously gown and experimented on over the years, allowing for a constant medical reference. As the cell shouldn't be susceptible to cancers from bad divisions, the only issues with the cells should be introduced ones provided the initial sample was healthy. This could prove valuable for medical research. While this does not affect evolutionary pressures in so many words, medical treatments will allow for some to reproduce that might not have been able to due to illness or disease. Likewise, if the immortal's status is known, they might become a sought after commodity for unscrupulous humans to serve as genetic fodder in hopes for immortal children. Their drive to reproduce might be hampered by persistent people that will not take no for an answer. As has been brought up, they might also be driven from a smaller settlement once their status is known as they will be "the other" at that point and the (possibly jealous) mortals may force them out, meaning the immortal will have to find a new place to live. Then again, the opposite might be true if the society reveres its elders. [Answer] TL;DR: Evolution would eventually solve any potential problem by your population evolving not to reproduce with the immortal. Let’s assume for the sake of the argument that the answer to your question is yes, i.e., the immortal would stagnate its species population. Then, on the long run, the tendency to mate and reproduce with the immortal (and possibly its close descendants) would be a negative trait itself as the subpopulation having that trait cannot evolve. Thus a subpopulation would evolve that does not reproduce with the immortal and is immune to whatever negative population-genetic effects the presence of the immortal has – which contradicts our initial assumption. Whether this subpopulation forms a new species or takes over the entire population depends on the details. Mind that there are several instances where traits evolved that do not have an direct positive effect, but that primarily effect genetic diversity and evolvability, e.g., the [Westermarck effect](https://en.wikipedia.org/wiki/Westermarck_effect) which avoids incest, [the evolution of sex](https://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction), or the evolution of mutators in the [E. coli long term evolution experiment (Lenski experiment)](https://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment#Changes_in_fitness). ]
[Question] [ This is another branch of my [previous question](https://worldbuilding.stackexchange.com/questions/205376/a-huge-asteroid-is-going-to-hit-how-many-people-can-the-world-put-into-mostly). Currently, in real life, space agencies around the world charts and tracks asteroids and other objects that orbit the sun. They project the object's orbits and basically do simulations of their future orbits to determine whether or not the object will intersect with the Earth in the future. That's how their "prediction" works. However, in my scenario, the 20-km object appears out of nowhere (a dimensional rift that closes soon after, so no one knows about it) as shown in the diagram below. The Earth and the asteroid are both traveling counter-clockwise. [![Meteor Diagram](https://i.stack.imgur.com/7pD9U.png)](https://i.stack.imgur.com/7pD9U.png) More Asteroid Information: The asteroid has a reddish crystalline surface, with a mass of approximately 2.5 times Chicxulub despite being double the diameter. Question: Given current technology, around how long would it take the Earth to realize that they will be hit? To be more generally applicable, given no past orbital data, how long would it take astronomers to figure out whether or not a given object will strike Earth in the near future? Accepted answers will give a rough time-frame and justification. Optional but Relevant Question: If the above question addresses the combined capabilities of the agencies of the world, how would the answer change as access to information decreases? Say, a stargazing guru or some guy with a telescope. (This might belong in Space exchange, but given the sudden appearance of the meteor and the dimensional rift, I thought I might try here first. Vote to close if it doesn't belong here.) [Answer] According to your diagram, the 20-km asteroid pops out of nowhere while less than 0.2 AU from earth, and 6 months before impact. It is at about 1 AU from the sun, thus presenting a well-lit half-hemisphere to observers. It will be detected that same night. The asteroid will be visible as a magnitude 7.5-9 point. This is dimmer than the naked human eye can see, but well within observation levels for even backyard amateur astronomers, of which there are tens of thousands scanning and photographing the skies each night. It will have a rather high proper motion against the sky, making it glaringly obvious on any photograph of that part of the sky. However its motion will be too small to fit any normal (not GSO) satellite. Any astronomer seeing it on a photo will think they have discovered a new comet, and will repeat observations over the next few nights, thus quickly figuring out that something was irregular about this object. So 6 months (minus a few days to detect, identify and characterize its properties) worth of warning. 6 months is not enough time to deflect a 20-km rock! Not without preconstructed assets ready to launch immediately. In the normal run of things, even now, our observation capability is good enough to detect such a large object at least 5 years ahead of time, and that is assuming it snuck up on Jupiter and got slingshotted at Earth. Any other trajectory the expected detection time would be multiple decades. They will be able to hit it with a nuke, fragmenting it, causing much of the asteroid to miss. But a hefty percentage will still hit Earth, and a fragmented asteroid of that size is possibly even more dangerous than the intact thing. As for the time from detection to prediction of impact, it depends on the quality of data available. For something THAT bright, and THAT close to Earth, they could hundreds of observations from around the globe, thus providing actual parallax measurements which will nail down the distance, direction and speed to very tight limits. Close enough to identify it as a potential impactor withing a day or two. Knowing it to be a potential danger, it is close enough that they could then ping it with a radar, giving distance and position and speed information down to millimeter accuracy. Yes, the Goldstone Solar System Radar can and does make such observations. It is normally booked in advance like crazy, but for a discovery like that, the Powers will prioritize immediate examination. [Answer] The dominating time issue is detection, which is measured in years. Tracking the objects is faster, on the order of months. There's simply a lot of empty space out there, and it takes time to sweep it for objects. As an example, consider the space surveys of [Near-Earth objects](https://en.wikipedia.org/wiki/Near-Earth_object) (NEOs). There are a collection of detection activities out there, collectively termed as "spaceguard:" > > As a result [of spaceguard activities], the ratio of the known and the estimated total number of near-Earth asteroids larger than 1 km in diameter rose from about 20% in 1998 to 65% in 2004,[8] 80% in 2006,[64] and 93% in 2011 > > > This can be used to determine detection time probabalistically. If we can detect on the order of 10% of objects in 1 year, then it should take on average 10 years to observe the object. This is just to identify a NEO. The next step is to identify the likelihood of an impact. We don't really know this for certain until much too late. N-body orbits are too messy on the scale of one Earth radius. However, once again we can do things statistically. There are two scales that we grade NEOs on for impact risk, the [Torino Scale](https://en.wikipedia.org/wiki/Torino_scale) and the [Palermo Scale](https://en.wikipedia.org/wiki/Palermo_Technical_Impact_Hazard_Scale). Your object would get graded on these scales. This process happens rather quickly, with a reasonably small number of observations. Obviously we haven't had any large strikes on our planet to test the positive direction (the direction you care about), but we do have evidence for objects moving in the negative direction, in which observations demonstrate that the NEO is not a high impact risk. And, needless to say, any object that is "interesting" is going to get a lot of observations rather quickly. As an example case, the comet C/2013 A1 was on a potential intercept course to Mars. In March of 2013, it was predicted to have an impact probability of somewhere on the order of 1:1250. By April 2013 this was reduced to around 1:120000 (an almost certain miss), so we can see that these numbers resolve on the order of single months. Obviously your storyline can fudge these numbers. If the object does something "noisy" as it appears from the dimensional rift, we would point a telescope towards it sooner, and thus cut down on the detection time. A stealth coating on the object would increase it. And more interest in spaceguard tasks would obviously devote more resources to cataloging objects. On the tracking side of things, a NEO with a high risk of Earth impact is going to receive considerable attention.This glut of raw observations could be processed into a good track faster, increasing its Torino and Palermo scores more rapidly. But these are some baseline numbers you can use for the real life process astronomers are undergoing today. As for your single-stargazer question, they can't really affect the timeline for tracking the object all that much. We depend on much more sensitive equipment to do this. Much of the spaceguard activities done in the USA was due to congressional mandate, and a corresponding budget. A rogue individual just doesn't have the precision needed to do this on a short interval. However, they could observe the object sooner. As a classic example, the [Messier objects](https://en.wikipedia.org/wiki/Messier_object) are objects catalogued by Charles Messier in the late 1700s. They are objects like galaxies and nebulae that are popular targets for amateur astronomers to look at. He wasn't actually trying to look at these objects. He was actually trying to identify comets, and developed his catalog of comet-like objects to help other comet enthusiasts to identify objects that are certainly not comets. So never underestimate the ability for an individual to look at the sky in a different way, and see something valuable and unexpected. [Answer] Asteroid detection is rather difficult, due to the normally small apparent magnitude of the object. For this reason the largest body of asteroids are detected when they are across from the sun, giving them the brightest reflection in the darkest part of the sky. Everything stated by Cort Ammon still holds, but two there are some things to consider. First, an asteroid of that size is rather large compared to most of the objects being tracked. For comparison, Bennu and Apophis measure 500 and 370 meters respectively, and they were relatively easy to find. Secondly, the appearance of such a massive object at such proximity might be noticed by inertial instruments. In any event, if detected when across from the sun, your diagram suggests three months of awareness of the object's existence. But because of it's size and proximity, as long as the moon is in the right place, you could probably see it with a backyard telescope, maybe even the naked eye (depends on how it's angled, what it's made of, etc.) [Answer] I'm not answering your direct question however I'd like to comment on your statement: > > ... the 20-km object appears out of nowhere (a dimensional rift that closes soon after, so no one knows about it) > > > You don't need any dimensional rift or wormhole or magic for asteroids to appear "out of nowhere". This page lists all asteroid "close approaches" that we know of either in the past or future (objects that came closer than the moon's orbit): <https://en.wikipedia.org/wiki/List_of_asteroid_close_approaches_to_Earth> Between 2010 and 2020 there were 22 asteroids that were discovered after they nearly miss hitting Earth. So they basically "appeared out of nowhere" because the human race did not know about them until it was after "too late". In the same period of time there were 16 objects that were discovered less than 24 hours before they nearly miss hitting Earth. I still think it qualifies as "appears out of nowhere" if we discover something today that will hit us tomorrow. Between 2010 and 2020 there were only 7 objects that nearly missed Earth that were discovered more than 24 hours before. Out of the 7: * 3 was discovered the day before * 4 was discovered less than one week before Out of all the asteroids that nearly missed hitting us between 2010 and 2020 none were discovered more than one week before its close approach. There is very high probability that if an asteroid were to hit Earth we will not see it coming more than one week before hitting us. So you don't need any excuse for appearing out of nowhere - that's just the reality we live with today. Your readers however may not be familiar with our history of detecting objects that may hit our planet. So instead of conjuring a portal or wormhole or some magic I'd just explain to the reader our real-world history then say something along the lines of: > > ... and so it was that we discovered asteroid ABC123 just under one month before it would hit Earth > > > [Answer] It depends on where it is and how fast it's coming. For most situations it's bright enough some comet hunter will find it pretty quickly. However, if it's coming from not quite out of the sun and coming in fast it might not be detected until very soon before impact. If it actually occludes the sun some solar telescope would spot it. However, in the zone near the sun but not in front of the solar disk there are very few observations due to the light spilling in from the sun. Big scopes are never pointed anywhere even near the sun and few scopes are pointed within a few degrees of the sun at any time. ]
[Question] [ I know that in real life, asteroids tend to be hundreds of thousands of kilometres apart. In fiction, asteroids are often very close together, maybe a few hundred metres. Obviously this is much more exciting. In the short story I'm writing, I want to include a battle scene set in a dense asteroid field like the one in "The Empire Strikes Back". This leads me to my question: is there any scientifically plausible reason for the existence of an asteroid field or belt containing millions of asteroids tightly packed together? [Answer] We need look no further than [Saturn's rings](https://www.space.com/23235-rings-of-saturn.html). > > Saturn's rings are made up of billions of particles ranging from grains of sand to mountain-size chunks. > > > Pioneer 11 [passed through the outer rings](https://solarsystem.nasa.gov/resources/722/pioneer-11-at-saturn/) and although it came close to hitting one of the two new moons it discovered, it survived, suggesting that the density of the outer rings is low enough to not give you the effect you're looking for. However, I believe the density of the inner rings are. The Cassini probe discovered evidence that there may be [millions of moonlets in the rings](https://www.theguardian.com/science/2017/jan/31/saturns-rings-contain-millions-moonlets-new-nasa-images-reveal-cassini). That suggests mountain-sized to me. *So, can we have a large field like in the Empire Strikes Back?* Of course we can. But there are some caveats. 1. Gravity is not your friend. When you get mountain-sized asteroids in close proximity, gravity wants to pull them together to form planets. This process takes a honking long time — but it's nevertheless going on. So why doesn't Saturn's rings coalesce? Because the gravity of Saturn and the orbit of the rings keep them churned up like a food mixer. 2. All that cool flying around in The Empire Strikes Back, without the use of Star-Trek-grade "inertial dampers" would turn most passengers on a space ship into a thin pink marmalade on the side of a bulkhead. [This cool bit of space math](https://spacemath.gsfc.nasa.gov/weekly/10Page28.pdf) points out that the orbital speeds of Saturn's rings are up to 24 Km/s. That doesn't sound like much until you convert it into Km/h (86,400 Km/h or Mach 70). This means you need a lot more space between those asteroids to give you maneuvering room than the folks at Lucasfilm led us to believe. So if you want "real," you're not actually looking for what the film did. You need the asteroids spread out much more (there'd still be plenty of high-stress flying around!). I don't believe we know yet of any such fields outside planetary rings, but we're only just beginning to view our galaxy with detail. That being said, I can think of no reason why they can't. In fact, I think for the sake of a story it would be very plausible to find them in or around nebulae or orbiting newly-formed stars. [Answer] Make the field a very recent creation. Say a planetoid was recently captured by the planet and torn apart because it's orbit was inside the Roche limit; just enough time has elapsed to break it's pieces into a nice debris field, but not enough for collisions and orbital decay to make it too sparse. You would of course be cherry picking a rather brief window of time (astronomically speaking,) but what interesting story isn't? [Answer] Trojans might help suspend disbelief Asteroids are collected at the Lagrange points of planets, in our system notably the [Trojan](https://en.wikipedia.org/wiki/Jupiter_trojan) points of Jupiter. While they are still not dense enough, a soft SF story might mention that the battle happens "in a dense patch of the trailing (or leading) Trojan point." Alternatively, consider going to the [rings](https://en.wikipedia.org/wiki/Rings_of_Saturn) of a gas giant. Again less dense as you want, probably, and it might not contain sufficiently large rocks. [Answer] The asteroids carry electrical charge. <https://www.youtube.com/watch?v=qHrBhgwq__Q> [![water droplets and a knitting needles](https://i.stack.imgur.com/UWZxm.jpg)](https://i.stack.imgur.com/UWZxm.jpg) This great video from the space station shows droplets of water orbiting a charged knitting needle. Rather than the attraction of gravity, they are attracted because of charge differences. You have to have a fair bit of mass to produce serious attractive forces. But electrical charge can pull lightweight things together. This is the case for your asteroids. Because of their composition and the fact that they are whacking into each other and rubbing against each other, many of the asteroids have acquired electrical charge. They attract each other and so remain in a cloud. Perhaps a solar wind inputs energy and charge as well, keeping the assembly dynamic. [Answer] I do not think this is what you are asking for, but I have it like this in my space horror novelette: Hero's planet was cut off from civilization for 1000 years . In reality, most of the humanity was destroyed by bio-engineered virus - aliens just overlooked this little colony and with little bit of luck, supply ship never arrived and virus never got there. It took the colony 1000 years to built themselves back to interstellar technological level (they had knowledge, just not resources). Hero one day found another shard of human leftovers - mining and refining space station in asteroid field (It is huge station - where miners and metallurgist lived with their families + required infrastructure). Despite being dead, the station operated for next 500 years and while no FTL ship was available they had at least short-range vessels and pulled near asteroids together and used them for whatever they needed. For expanding station, fuel, spare parts etc. Over 500 years the Mining station accumulated thousands of various asteroids in huge cluster around station - the field in my settings is really small - just a bubble in diameter 100,000km. But perhaps you could use this idea and make it as a some huge junkyard or storage field for mining facility - perhaps even whole ring around some industrial planet. They just pre-stocked asteroids. Sorry I love One-Product Planet and Planet of the Hats trope so I use it a lot haha [Answer] If these object don't have to be asteroids but could also be comets, there is a simple mechanism by which you could end up with a trail of many comets. A comet can break up into many pretty large fragments as it passes near the Sun. Those fragments will all have almost identical orbits, so they will be very near one another (see for instance the [Levy-Shoemaker comet](https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9)). You don't say how big the field has to be, but this might be one option. [Answer] Very recently there was an Earth-shattering kaboom, and now there's 6×10²⁴ kilograms of junk out there. It's mostly all moving away from the center of mass of the planet, and it's all superheated and glowing white-hot. Gradually it will spread out and form a ring, but it will be millions of years before the collisions become rare. ]
[Question] [ Imagine a species that is very much like humans in shape, size and physiology. But they are able to stare at the sun for long periods without suffering any harm, and without needing any artificial device. Suppose the evolutionary pressure for this is that they come from a much brighter world. How could they evolve sun resistant eyes? I would like them to have visual 20/20 vision, and acuity and color resolution equal or close to ours - but that is NOT a constraint. If the capacity to stare at the sun requires their sight to be worse than humans' in some aspect or another, so be it. [Answer] There are four ways to mitigate bright light which both biology and photography are employing. 1. Diaphragm (pupil). Your species can shrink their pupils to a very tiny size, filtering out as much light as necessary. In addition to that, their eye color should be black, otherwise the light bleeding from the iris would overwhelm the light coming through the pupil; 2. Filter ("third eyelid" membrane). Extra light can be filtered out by a [Nictitating membrane](https://en.wikipedia.org/wiki/Nictitating_membrane), which is present in a number of animals and vestigial in humans. To protect from bright sunlight, it has to be dark grey in color; 3. Sensitivity. The retina itself can be accustomed to bright light and have mechanisms to avoid damage. This is probably the hardest way to achieve desired results, because human retina already has quite wide dynamic range; 4. Exposition. Your species should be blinking in the bright light. In humans, blinking is compromising clear vision, but there is no real reason why species can not adapt to it. [Answer] Star Trek's Vulcans have evolved a nictitating membrane that shields their eyes (Spock's World by Diane Duane and TOS episode "Operation -- Annihilate!"). But this is a bit of an emergency measure. It would also be possible to have a [photochromic](https://en.wikipedia.org/wiki/Photochromic_lens) layer on the cornea, and it could even be active. That is: when hit by ultraviolet rays, or by a strong enough light, the cornea darkens. Also, a small biologic current is ran through the vitreous body, aligning [special protein chains so that they act like a shutter](https://en.wikipedia.org/wiki/Liquid_crystal#Nematic_phase). The two phenomenons are independent and can compound each other, allowing a continuous regulation of light. Brain adaptation can then compensate color skew, giving 20/20 visus and optical and chromatic resolution similar to that of humans. Nematic cholesterol-like chains can offer light attenuation up to 95%, and I think that a "darkened" cornea should be able to easily provide another 20%. This means your aliens should be able to achieve comfortable photopic vision at illuminations of more than two million lux, and still see perfectly well in Earth-normal room lighting (their luminance range would go from around 10-2 to 108; they'd probably fall to scotopic vision at early dusk, and be unable to see on a clear starry night). On the other hand, an overcast day would probably look to them quite dark, because they'd get the 20% attenuation from the cornea due to the UV component unfiltered by the clouds. [Answer] Polarized Lenses. Making your creature's eyes' lenses polarized would help to block sunlight and glare without having to have extra eyelids or tiny pupils which will be detrimental to its eyesight. Here is a quote about polarization of sunglasses: > > Today’s sunglasses—with or without prescription—can be modified with a technique called polarization to reduce light glare and improve vision and safety in the sun. > > > Not only are polarized lenses not detrimental to eyesight, they are supposed to enance it. > > Polarized lenses not only reduce glare, they make images appear sharper and clearer, increasing visual clarity and comfort. > > > Also, you could use two lenses instead of a dilating pupil. The way polarization works, you could have two polarized lenses on each eye of your creature. Instead of opening/closing its pupils to block light, it would merely need to rotate one of the lenses to immediately adjust its eyes to a bright light. As the lenses' polarizing filters intersect more directly, they block more of the light. [Answer] Do you mean "How to evolve?" literally? Evolution isn't something that tries to achieve a goal. In general, it is a meaningless random process that takes a large gene pool of many variations of genes, and then kills off individuals that lack the specific genes that will help them to survive long enough to produce children. The number and frequency of genetic variations (mutations) can be increased by radiation or chemicals, but those same factors can also be fatal, and the mutations can produce many strange and undesirable results. So, assuming there are sufficient variations available, you will need something that will cause people that have sensitive eyes to tend to die before they reproduce. That something can be natural or artificial. For a natural process, perhaps for some long but limited period of time the sunlight becomes much brighter than usual and people with sensitive eyes end up with very poor vision or even blindness. They will tend to die early or be found unsuitable as mates, and so not pass on the "bad" genes. For the most part, only those individuals that have genes that allow them to tolerate bright sunlight will propagate their genes to the next generation. For an artificial process, perhaps society requires a rite of passage ceremony during which people of a certain age, whether 8 days, 12 years, or whatever, are forced to stare at the sun for a full minute (or some other duration). Again, those that carry the sensitive genes will end up blind or with damaged vision and will be unlikely to have children of their own. Whatever it is that increases mutations, and whatever it is that kills off the unwanted attributes, are of little importance. The selection process for who gets to pass their genes on to the next generation is all that counts. [Answer] First, your humans need a mutation that for some reason provides an evolutionary advantage to be able to stare at the sun or a co-evolutionary mutation that is co-joined with that mutation. As an example, a mutation that results in a lens that under muscle strain polarizes -- attenuating the light. If that mutation spreads into the gene pool and flourishes and somehow provides an advantage in spreading the mutation then future mutations can promote and increase that ability. Somewhere there will need to be an improved tolerance for UV radiation. It causes cataracts. So if humans are going to be staring at the sun before we invent telescopes, that feels like it needs to be more resistant for the individuals to benefit from staring at the sun Another mutation might be that the viscous goo in the eye might be self-polarizing or become less opaque in the presence of strong light. Our eyelids could become thinner, allowing us to see bright things through them Any or all of these of millennia of natural selection might combine to let humans star at the sun. [Answer] # They Were Prey I will try to explain the why and not so much the how. On this planet these humanoids were not at the top of the food chain. There were multiple flying predators which loved to feast on them. These predators learned / evolved to dive bomb when they were directly between the sun and their prey. Their prey not being able see them would have little chance of escaping. Over many generations and mutations this humanoid species eyes started getting a feature that helped them look closer and closer to the sun. Those who could look close to the sun were more likely to avoid being lunch for these predators. Eventually this feature was refined to allow the humanoid to directly look at the sun with no ill affect. This feature could be an extra eyelid with the same properties as sunglasses or new sensory cell(s) that are impervious to the harmful rays of the sun. [Answer] It's not possible. You killed this possibility yourself with the stipulation: "a species that is very much like humans in shape, size and physiology" No species on Earth that meets this stipulation has a need for staring at the sun for long periods. Not a survival need, which means that evolution could not, by definition, EVER act to produce such an individual ANYWHERE on ANY PLANET. IF you remove that stipulation and say something like "a species that LOOKS like humans but has a completely oddball physiology that for some inane reason requires staring at the sun" then yes, you could create some evolutionary issue that might produce this. But I have to warn you - staring at a bright light source for a long time leaves that individual vulnerable to predators. So if for example you created a specie that had to "charge up by staring at the sun" for an hour every day - then that specie would quickly be eliminated because some OTHER specie on that planet would rapidly evolve the ability to NOT have to stare at the sun - so that they could run up and kill off and eat the specie that did have to stare at the sun in the morning while it was busy doing it. By extension this applies to staring at ANYTHING for a long period of time. Not just the sun. This is why when mammals evolved they out competed the reptiles and killed most reptile species off - because they could kill and eat the reptiles in the early morning when the reptile was still sluggish and warming itself. Thus the adage "early bird gets the worm" (this is an "idea evolvement" that created the phrase which in a general sense means that if you go out hunting early in the morning you are more apt to catch prey that is still sluggish in the morning. Worms are no more accessible to birds in the early morning than anytime else in the day) The requirement for not moving and staring at something for a long time or doing something for a long time is an evolutionary disadvantage and once Nature figured out how to dispense with that, the individuals who didn't have that restriction killed off all the individuals that did. It's why we invented Drive Thrus, son. ;-) What you have to keep in mind is this - when using the "rules of nature" that are in force on Earth you must remember that humans are the end result of hundreds of millions of years of evolution following those rules - and we are very very successful, if not the most successful specie. So you have a VERY high bar to use those rules to produce a "human-like" specie that is going to have significant differences from real humans. Nature has been working on it for hundreds of millions of years and we is what she came up with. So no triple-breasted women, sorry!!! Earth couldn't even keep 2 separate "human-like" species going - Homo-Sapiens and Neanderthals - for much more then a couple hundred thousand years before the evolutionary advantage of Homo-Sapiens killed them off. If you want to say "Earth's rules of nature" are absolutes anywhere in the Universe then in order to get something significantly different than a human you are going to have to fundamentally alter the environment - make the planet bigger or remove most carbon or something of that nature - in which case you CANNOT naturally evolve ANY specie that is going to be "like humans" in physiology. One of my favorite SF authors is Harry Harrison and in his Deathworld trilogy he took wonderful liberties describing Meta as among the most beautiful woman the protagonist had ever seen - the extra heavy gravity brought out her firm strap-like muscles and so on - in reality the most successful female on Deathworld would have been a squat, fat, tremendously muscled apish female that waddled around. But it was fun to read so don't let my throwing cold water on the idea dissuade you! :-) ]
[Question] [ Spells in this world is broken down into several categories, each designed to fill a certain niche: Enchantment Spells * These are spells designed to capture cosmic power within a crafted item, so that its power can be called upon in times of need. Protection Spells * These are spells designed to ward a user, object, or location against a variety of possible harms Transmogrifcation Spells * These are spells designed to fundamentally alter or control another living being or creature. Transmutation Spells * Changing the makeup of different materials or combining them with others to make new forms of matter. Divination Spells * These are spells designed to allow a user to perceive in ways that go beyond his five senses. There are two kinds of magic systems: sorcery and druyadism. Sorcery involves using the individual's own finite mana (life energy) in order to create effects in the physical world, and must be replenished after long periods of use. This form of magic requires circles, various materials, and can take anywhere from 30 minutes to several hours. Druyadism doesn't use the person's mana, but involves the mana of nature itself, which is infinite. This form of magic is more ritualistic, requiring hours to setup, and requires certain steps in order to work. I need for both of these systems to be able to perform the kinds of spells I mentioned. However, I need them to be used for different purposes for different reasons. People should need to choose between one of these forms depending on the situation. How do I design rules that that revolve around balancing these systems, so that they are capable of doing the same things but used for different needs? [Answer] Sorcery doesn't work well in areas where the world's magic is strong. Kind of like trying to connect to WiFi near a microwave oven, sorcery can't be used reliably in areas where the world's mana interferes with a person's internal mana. This unreliability can be accounted for in a few ways. If you have enough people casting the spell together, it will work if their combined mana can overcome the mana of the surrounding area. You can also cast simpler spells fairly well, since there isn't much room for error. In either case, you'll use much more mana than you would otherwise. Very complex and powerful spells are almost never going to work correctly and can't be cast without extreme risk. This also helps you explain the difference in casting times and methods between your two systems. A person has control over the flow of their own mana, but the complex patterns of the world's mana can't be controlled or predicted by people. Thus, your caster has to spend extra time attuning themselves to the world's mana flows. Since the flow can't be directed the way the spell typically demands, druyadism casters have to modify the spellcasting technique to utilize what's available. Changing up the recipe like this means that natural mana influences the spell in subtle ways, but the caster can still achieve the exact effect they want. This also means that druyadism has issues in areas where the world's mana is weaker. Amassing more casters won't help here like it does with sorcery. Instead, the caster needs to expand his ritual area, and spells might require even more extra steps to compensate. [Answer] Different methods take different time or effort. Lighting a fire to cook your dinner might take an hour of chanting with druyadism, or 3 seconds to snap off a quick fireball via sorcery. Harvesting apples from a tree may require targeting every fruit individually using sorcery, but druyadism lets you ask the tree for sustenance, and run around catching the produce as it all falls down. People who know how to use both sorcery and druyadism will look not just at the end result (which would be almost the same for both spells) but for the time, effort, energy and complexity required to get there. The cost-benefit may vary based on which of those you currently value the most (e.g. a long-but-easy spell is fine if you have a lazy afternoon free, but if you are rushed for time then the faster hard-and-draining spell is better) [Answer] Imagine you want to boil some water to brew some tea. How can you achieve it? * You can put the water on some fire to supply energy * You can use an electric resistance to supply energy * You can dissipate mechanical work to supply energy * You can drop some radioactive element to supply energy * [...] In all the above cases the effect is the same (the water boils), but the mean is different. If one has wood, it makes sense to use fire. If one has electricity, it makes sense to use electric resistance. Use a similar approach with your magic systems. [Answer] The less symmetry the better. For any kind of real, robust balance, you basically need things that one kind of magic is compeletely incompetent at, that the other isn't. And the set of such areas needs to be broad and important. If there isn't a lot of symmetry, then one of the two will turn out to be more useful. If you then add in any kind of iterative improvement/investment possibilities, investment in the more useful one is going to make it blow the other one out of the park. As an example, the [rotary or Wankel car engine](https://en.wikipedia.org/wiki/Wankel_engine). It has a number of fundamental advantages over the cylinder engine we use for cars, and for a long time it competed. But the advantages where not asymmetrical enough, resulting in far more investment into optimizing the cylinder engine. Even in areas where the Wankel engine is theoretically better, the heavily optimized cylinder engine can match or exceed actual Wankel engine performance. Find some split in the set of problems. Maybe Sorcery magic doesn't work on "organic" matter (including plastics) directly, while Druyadism doesn't work on metals directly. So a Sorcery protection charm would work on Chainmail, while Druyadism could protect a human directly, or work on relatively normal clothing. Sorcerers would harvest apples by enchanting scissors and metal baskets. Druids might directly enchant the trees and some plastic bags. [Answer] If energy is energy, you should be able to convert one into the other, or at least use them for the same purposes. So, we take as a given that both sorcerers and druids can do all of the kinds of magic. On the other hand, why would one prefer one or the other? Sure, they have some symmetry, they need a bias. In particular, we know that druids has access to a larger pool of energy (Nature mana). Plus you handicap sorcery in that it requires down time. That gives a remarkable advantage to druids. Why would one want to use sorcery? I have some ideas: * Individual mana is limited, but it is readily available. On the other hand, Nature's mana is limitless, yet it flows much slower. This means that you can accumulate large quantities of Nature mana over time for a huge spell. However, if you need to cast on a pinch, you will be using Individual mana. * Using Individual mana hurts the caster, it might kill them. It would be foolish to use carelessly. Thus, anything done with good setup will probably use Nature mana unless there is reason to do otherwise. * The caster has much better control over Individual mana. Using Nature mana could result in worst precision. Meaning that anything that needs to be done carefully is probably done with Individual mana. I want to note that we can workaround these limitations. On one hand we can have Nature mana stored for later use, and on the other we can have many magicians giving some of thier individual mana to be able to make a huge spell. Yet, executing these workarounds requires prep time and coordination. Thus, these are not the common case. We can also argue that with training a magician could become better at controlling Nature mana, or increase their pool of Individual mana (or both). In fact, having these be two distinct paths of progression for an individual would mean that magicians would not be switching on a whim. --- Which kind of spell would be done with Individual mana or Nature mana? all of them. The difference is not on the categories you have. Instead it is on their scope. However one will be more common than the other for each one. Enchantment Given that Enchantment is something done in preparation for later use, we can expect that most enchantment is done with Nature mana. (Heck, you say they use "cosmic power", I don't know what you mean by that, but I would bet it is not Individual mana). On the other hand, complex enchantment might require finer control, meaning that magicians would have to use Individual mana to do it. Which also means that those are enchantments that are not done often. I would also assume that there is improvised ad-hoc enchantment, something that a magician could do to get by in a dire situation where there are not many resources or time avaiblable. That could be done with Individual mana. Again, not a common occurence. Protection When we do a protection spell, does it last forever? I would expect protection spells to decay. That suggest that a strong protection spell is done with Nature mana (so you can put a lot on it, and perhaps keep adding). Yet, on a pinch, the magician could draw some Individual mana for an ad-hoc protection spell. It comes at a trade off, of course, yet if it protected the user from a particulary nasty spell that took'em by surpose it might be worth it. I suppose not all protection magic is negating casts and placing shields. In fact, I bet people who learn to make a seal learn to break it. However, bypassing the security protection of a spell probably requires finer control than setting it up. In fact, magicians might not know before hand if we are going to have to do it, so no prep time. Oh look, they are preparing a nasty spell inside, we must break in fast! Making this a good candidate for Individual mana. Transmogrifcation Transmogrifcation could be like surgery, you need to put the right ammount of mana in the right places. And to do that you need very fine control. Also, we are acting on a living and kicking being that will not wait for the Nature mana to accumulate. I think Transmogrifcation will often be done with Individual mana. I do not know your setting, however, I can imagine that some special creatures could require much more mana than the average individual could deliver. Making the use of Transmogrifcation on them a large project. Perhaps some try with Nature mana, accumulated for the occasion. In fact this could be a good situation to bring up the might-go-wrong trope. Transmutation Moving stuff around or doing chemestry with magic should not be expensive. There energy is there in the matter, the magician needs to channel it. I think Individual mana makes sense. However, when it comes to converting an element to another, are we not talking about holding a nuclear reaction with magic? To convert lead to gold the magician will probably need a lot of energy. I know there is an argument for fine control here, yet, if it were to go boom fine control is buying you nothing. You want strong containment instead. Thus, I would suggest Nature mana for that. Oh, about it going wrong? it would mean you don't get the substance you were expecting, or not as much quantity. It is about precision. So, no it will not summon a monster or open a black hole. Divination I can think of a few things to fall in here: * Percieve what is far away * Percieve mana * Percieve the future * Percieve the past (psychometry or trace scrying) * Percieve luck? I do not know if that is a thing in your setting * Percieve love? I do not know if that is a thing in your setting * Percieve truth? I do not know if that is a thing in your setting * Percieve... ern... microwaves? Those are what? eight spell? Is that all from this school? Future, past and far away are defying space-time. I'll put those on "needs a lot of mana" and say that people probably use Nature mana for anything significant. Which could mean that things could not be seen as clear or even predictions sometimes go wrong, makes sense to me. Percieve mana has to be something usually done with Individual mana. Because I find it hard to believe that magicians learn to control Nature mana before percieving it. As per other odd senses, I would say they are Individual mana too, following the same ideas as in Transmogrifcation above. --- For abtract: Of course Individual and Nature mana can be used for any case, yet some are uses are more common: * Individual mana is often used for: complex enchantment, ad-hoc enchantment, ad-hoc protection, breaking protection, common transmogrifcation, trivial transmutation, mana perception, odd divination. * Nature mana is often used for: common enchantment, common protection, special transmogrifcation, deep transmutation, spacetime divination. There is wiggle room and I have mentioned things that I have no idea if they exist in your setting, also a few of these things could made less practical by the time to prepare the rituals. And as I was saying in the answer to your prior question, some of these categories could be underdeveloped, which is another way to nerf them. So, feel free to move around what I said. It is your world. [Answer] I don't recall the system, but there was one I played years back that had a similar differentiation between magic that they called rituals and rotes. Rotes were spells that you memorized ahead of time to perform exactly the same way every time, so they were very specific. Casting a rote spell was pretty much guaranteed to succeed, and only took a moment and some mana to cast. The second you wanted to change a detail about the spell, it had to be treated as a ritual. You would have to sit down and plan out all of its details for several minutes, hours, or even days, to be able to cast it depending on how extravagant the spell is, and how similar it is to your existing rotes. As your mechanic stands, a person would typically be compelled to use their mana to do things faster since they could just fall back on the power of nature when they need to. But memorization takes a lot of time; so, wizards would have to be mindful of what's worth putting that much time into learning, and what's worth doing ad hoc at a disadvantage. [Answer] All systems of magic are systems of manipulating energy. - credit my (then) 6 year old son, after watching "Avatar: The Last Airbender" and "Naruto". In your case, it's much simpler because both systems you posit are manipulating the same mana, just obtaining it from different sources. Druyadism is the foundation of both systems. It provides the basics of tapping into mana sources and the foundational spells. Sorcery is learning to tap into your own mana, which is decidedly more limited in scale but infinitely closer at hand than all of nature. Sorcery is quick and dirty, and comes at higher personal cost. You can tap your own mana quickly and efficiently, like going to the pantry for a can of beans, but you can't sustain anything really demanding or prolonged, like feeding 500 people for three days. Since you can be quick and dirty about it, and it doesn't need to last, people are prone to take shortcuts and do half-way jobs "just enough to get it done so we can move on to the next problem". Druyadism requires more preparation - like going down to the local restaurant supply shop, but allows a mortal to perform larger feats for a prolonged period of time than they could on just their own mana. ]
[Question] [ A hunter-gatherer society exists in lands similar to that of Bavaria. There is plentiful game in the forests and glades, and there are many rivers with edible aquatic life. Smaller rivers can freeze periodically in the winter. Food preservation by smoking and salting are known. Gathered wild grains and acorns are gathered food items that might survive a winter. The advantage of staying put is that a well built shelter from the cold could be maintained and stored foods could be kept all winter long. On the other hand, food storage is minimal for hunter gatherers; moving food via sled is relatively easy in the winter; and cold protection is primarily skins and blankets, and not dependent on well built huts (which don't really exist). The advantage to moving in the winter is that food supplies are much more limited. Moving more frequently puts less pressure on the surrounding environment. Is it a better strategy for survival for a hunter-gatherer community in a cold winter environment to move a few times each winter, or stay put in one location? [Answer] If I check what the experts do, I would say: move before winter. And the experts in question are animals used to deal with winter. When they migrate, they do it before winter, so that they don't have to move during harsh conditions. When they don't migrate, they still reach more livable conditions (think boars or wolves moving to the valleys instead of staying on the mountains). Consider that moving in winter is a high effort and high risk. Therefore you do it only if it is the lesser evil. Summarizing: * Move before winter * If the situation is getting out of control (severe lack of resources) then consider moving to a more favorable location, else stay put. [Answer] Hunter gatherers are tied to food sources, so it would depend largely on what is available in the locale. If you live next to the sea you would develop the skills to exploit the sea in winter and could live off nothing but meat for the duration like eskimos if need be quite comfortably. Scottish Isles the hunter gatherers gathered and stored large amounts of resources and then overwintered in a locale. It's actually rare even in more temperate climes for hunter gatherers to always be moving unless the is population pressure or external pressure. I can't think of any except Aboriginal Australians and even for them it was individuals who would roam off for extended periods, not the whole group. Normally they will have several locations with semi permanent camps which they stay for periods in while they exploit and store resources. Eg, nuts in one area, deer in another for antler and skins and whatever, shellfish in another. The winter camp would be just one of these. The only reason I can think of to normally change locales during winter is if a particular resource becomes available elsewhere partway through such as an animal migration or massing of fish or something similar. Straying out of your area could also be dangerous, eventually you will impinge on another group and there will be conflict over resources. [Answer] Simple answer to your "either-or" question is: Yes As others have stated, hunter gatherers were tied to food sources. Germany's prehistoric climate would have been vastly different than it is today, but suffice it to say that hunter-gatherers thrived in this region. As you stated, for most of the hunter-gatherer period, most of mankind lived in caves or other natural shelters. What this implies ([and supported by science](https://www.ancient.eu/article/991/prehistoric-hunter-gatherer-societies/)) is that "societies" of hunter-gatherers would be made up of small, dispersed groups. These groups are often thought to always be at odds with others, but [quite a bit of evidence](https://bhap.artsrn.ualberta.ca/images/uploads/pdfs/Weber_Goriunova_JAA_Special_Issue_2013.pdf) points that there was a lot of intermixing. Also, trade was actually a factor even during this time, meaning our hunter-gatherer ancestors had it in their best interests to be friendly when possible. (don't forget, they were every bit as intelligent as we are today) To answer your question, the best evidence I can provide is in the above link concerning a similar climate to prehistoric Germany. The Lake Baikal region has a lot of scientific literature available from this time period, but suffice it to say, there was intermixing (on a society basis at least) as various family-groups moved around between areas. The evidence points towards some groups moving and some staying. Why this is can be complicated to answer definitively, but it can also be answered simply, at least generally: Those who stayed saw benefit in staying, those who moved saw benefit in moving. Some would have been right, some would have been wrong. But if an area can't support a large group, some are going to have to move or fight for the limited food/shelter resources. It seems most humans chose to voluntarily break off and move to find greener pastures while some would stay and keep working the existing known locations. So basically, small family groups formed the very loose 'society' and would move around as necessary, not necessarily on a seasonal basis. Moving means burning energy, burning energy means having to find more food. As technology caught up (fire, shelter-building, better tools, eventually agriculture), their dietary budgets became such where taking risks could be allowed and true society started flourishing. [Answer] > > well built huts (which don't really exist) > > > Why not? because this is the crux of the question. Winter shelters are not that hard to make, wattled walls and thatched roofs can keep keep the cold out quite effectively and have done so for thousands of years. This was the preferred method for borth early Europeans and pacific-northwest native Americans. and if you indeed have a bountiful area there is little reason to trek around so the winter huts become the summer basecamp/storehouses. [Answer] It depends on their primary food sources. Moving has advantages and disadvantages. The primary advantage is access to food and supplies that aren't present or become depleted in a fixed range. The disadvantages are the time and energy costs associated with moving, as well as increased competition for territory with other migratory groups. Especially without domesticated animals, moving also places a severe limit on the types of infrastructure that can be relied on. Structures like granaries or fishing platforms can't be transported from one settlement location to the next. Whether the advantages outweigh the disadvantages largely depends on what type of food a specific group of hunter-gatherers relies on. If building infrastructure is important for survival, staying put in the winter makes sense. If a continuous source of easily accessible food is available, but at different locations during different parts of the year, moving makes sense. If your hunter-gatherers primarily hunt large, migratory animals, for example, then it makes a lot of sense to move before winter. So long as they stay close to their quarry, they'll have plenty of food. If the animals migrate south for the winter, or from mountainous areas into the valleys, the hunters, as well as their families, are likely to follow. On the other hand, a hunter-gatherer society that fishes from a river for most of their food will benefit more from having access to good boat launching sites or prime fishing areas than it will from migrating to a warmer climate. Even if the fishing is seasonal, it will likely make more sense for a fishing society to stay put for the winter, and rely on stocking up heavily on food. Fishing often requires infrastructure, either in the form of boats or in the form of fishing platforms, and migrations tend to be of the "out to sea" variety, which makes following them logistically difficult. [Answer] Normally, gatherer-hunter groups that live in areas with cold winters like Germany have specialized winter semi-permanent shelters. They gather large quantities of resources and move to those locations. Even bringing resources, they sill won't probably get through the whole winter without needing more, so different groups have different ways to get food. If they are close to water, they fish, like modern arctic tribes, if they are inside the continent they can specialize in hunting in winter conditions, like the Ainu people of Japan. With known ways to preserve food it is even easier to survive the winter. These shelters can become really complex actually, having protection against cold, using waterproofing, natural and man-made "caves" (remembering that every kilometer underground, the temperature usually increases 25-30 °C). But in the end, it really depends on what you want, even being the common thing to do, staying in one or few shelters was not always the only option, sometimes it was possible to move to warmer areas during winter and if you are specialized enough you can even move during winter, remember, some of our ancestors lived through ice ages, not only surviving them, but even were able to migrate incredible distances in them, like the people who went to the American continent using the lower sea levels and abundance of ice plateaus. So, to summarize, the best strategy, is to move to warmer places, if not possible, stay and specialize in winter survival, but ultimately, is is perfectly possible to move even in winter times. [Answer] <https://en.wikipedia.org/wiki/Hunter-gatherer#Habitat_and_population> > > Most hunter-gatherers are nomadic or semi-nomadic and live in temporary settlements. Mobile communities typically construct shelters using impermanent building materials, or they may use natural rock shelters, where they are available. > > > Some hunter-gatherer cultures, such as the indigenous peoples of the Pacific Northwest Coast, lived in particularly rich environments that allowed them to be sedentary or semi-sedentary. > > > <https://en.wikipedia.org/wiki/Nomad#Hunter-gatherers> > > 'Nomadic' hunter-gatherers (also known as foragers) move from campsite to campsite, following game and wild fruits and vegetables. Hunting and gathering describes our ancestors' subsistence living style. > > > Plants have different growing seasons, and migratory animals move with seasons. Lions in the Kalahari probably don't move south for the winter (they follow the grazing animals that follow the water), but you can bet that reindeer/caribou certainly do. ## Summary The whole point of nomadism is seasonally following the food. So... > > Do hunter-gatherers move or stay put in the winter? > > > Well, "Most hunter-gatherers are nomadic or semi-nomadic". That means... some aren't nomadic, but most move. ]
[Question] [ Basically, my current thought process is to have a virus that causes one to all vital organs to fail upon reacting to its components. It has to make contact with as many people as possible, therefore has to be airborne. The virus itself would be slow-acting, and can, for example, take longer to cure than it takes to kill, or be extremely hard to detect with countless variants. What I have so far is: * A pathogen resembling a normal human cell in both behavior and characteristics, making it hard to detect. * Bolstering its heat and cold resistance enough that killing it by heating or freezing it would result in killing the host as well. (Giving it general resistances to most common decontamination methods, basically.) * Making its hosts vitality vary by individuals, although surviving without taking countermeasures is impossible. I believe some pseudo-science can lead to such results, although my problem lies in its spreading. If it's hard to detect in a human body, then it would be relatively easy to find while travelling by air or water, wouldn't it? And spreading it by body contact is somewhat inefficient, since it would take a long time for it to spread everywhere, and I want its transmission to be as fast as possible. What I want to know is: * Are there elements that can attach themselves to oxygen molecules and remain undetectable? If not, then what would a "scientific" approach to making one be? * What kind of lethal elements to the human body are there that could result in organ failure upon contact, and / or cause visible effects? * Are there any air filtering methods that can cleanse oxygen molecules enough that such a pathogen would be removed? [Answer] First of all, a virus can never behave the same way a human cell does. A virus isn't a cell, it more closely resembles a capsule of proteins which contain some DNA or RNA with the building code if you will. It replicates by hijacking a cell's metabolism and protein producing organelles. One way to accomplish the slow acting but lethal effect you desire could be the virus inciting auto-immune responses. Basically trick the immune system into believing the body's own cells are pathogens and thus destroying them. You could add in the element that the virus can produce different immune responses in different individuals making the thing lethal and very hard to predict and detect since each individual has a lethal but different reaction. Lastly you could state the virus induces a cytokine storm, an often lethal overreaction of the immune system where it goes completely haywire. Edit: The fact that this virus messes with the immune system can also be the lead cause as to why curing it or developing an effective vaccine is nigh impossible. As for sticking to air molecules. The molecules that make up viruses are much heavier and larger than oxygen molecules, plus neither oxygen nor nitrogen are likely to form a reversible bond if the virus somehow reacts with said molecules. Then there is the point that the molecule will inevitably be much larger than normal air molecules thus unlikely to foil any scrubber designed to get such pathogens out of the air. Which brings us to your last question. Equipment to scrub viruses and other pathogens from the air exist, but are expensive and cost quite a bit of energy. Especially if they should be used at large scale as would be needed during an outbreak of this nasty pathogen. [Answer] We don't really use antivirals except under special circumstances (HIV). Treatment for viral infection is primarily about treating symptoms and waiting for the body to deal with it. We try to vaccinate (seasonal flu), but on the whole they're not cured. There are a selection of incurable viruses that once you have, you have for life. Most of these come under [herpes](https://en.wikipedia.org/wiki/Herpes_virus) group. These are contact transmitted but not often fatal with modern medicine, though they can be dangerous for vulnerable groups. If you want a virus to be fatal then immune overreaction is one of the most effective options. You could also opt for immune suppression if you want it to remain undetected. This results in a variety of causes of death meaning the real cause, the suppressed immune system, takes longer to be detected. Airborne transmission for viruses tends to be water molecule bound as they're too heavy for air alone, coughs and sneezes spread diseases. This means that air filtering and cleaning is viable. [Answer] You might want to consider the virus' lesser-known, but quite lethal cousin, the [prion](https://en.wikipedia.org/wiki/Prion) > > Prions are infectious agents composed entirely of a protein material that can fold in multiple, structurally distinct ways, at least one of which is transmissible to other prion proteins, leading to disease in a manner that is epidemiologically comparable to the spread of viral infection. Prions composed of the prion protein (PrP) are believed to be the cause of transmissible spongiform encephalopathies (TSEs) among other diseases. > > > The basic gist of a prion is that it causes a "bad fold" of a protein. That protein, in turn, causes more bad folding and so on. The most famous prion we know is [mad cow disease](https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy), which is so serious that cows infected are mandated to be destroyed. Humans that eat infected meat will eventually die. There is no cure, because prions set off a biological process that cannot be stopped. Prions meet all your disease requirements, save the transmission. Typically you get sick by direct exposure to infected tissue, but all you need is an agent that triggers production of a prion. Make your prion-inducer airborne and, by the time people realize they're sick, it's too late to stop. [Answer] [Prions.](https://www.scientificamerican.com/article/what-is-a-prion-specifica/) Prions are not viruses but a infectious and pathogenic version of a specific normal cellular protein. "Reproduction" occurs because on contacting the normal version, the prion protein catalyzes a switch of the normal protein to the pathogenic prion isoform. Prions are most famously known as the etiologic agent of [mad cow disease](https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopathy). Diseases in humans caused by this protein include kuru and Creutzfeld-Jakob disaease. The prion isoform of this protein becomes resistant to normal cellular housekeeping and clearance, and so accumulates. As it accumulates it progressively impairs neurologic functions. All the prion diseases are inexorable, untreatable, fatal neurodegenerative diseases. [Prions are extremely resistant to destruction](http://www.bseinfo.org/deactivationofprions.aspx) and normal methods of sterilization adequate to kill viruses and organisms can fail, including heat, cold, formaldehyde, radiation (UV or ionizing) and bleach solutions. Prolonged heat, strong acids or strong bleach is necessary. Prions from dead or sick animals can [remain in the soil](http://chbenson.engr.wisc.edu/images/stories/pdfs/Prions/Pedersen%20et%20al%20prion%20in%20soil.pdf) for years or even decades, and infect animals set to graze on tainted pastures. Readers on this site will be familiar with zombie lore and to me the prions seem zombielike: indestructible deranged versions of a normal entity, able to convert the normal version to the deranged version with a touch. Zombies generally do not persist in the ground for decades. Although... Re airborne: this absolutely can happen. Usually transmission is by eating infected material but there have been cases of transmission by [cornea transplant](https://www.ncbi.nlm.nih.gov/pubmed/9894930) and other solid organ transplant. [Aerosol transmission](https://www.ncbi.nlm.nih.gov/pubmed/23175370) has been demonstrated in deer. Basically if a copy of prion protein can get into you and contact a normal version of the protein, the disease has begun. The question is how fast it will progress and whether you die of something else before your brain gets sick. I think the reason mad cow did not wipe out the UK is because the cow version is dissimilar enough from the human version that it is a less effective catalyst. There is a known species barrier to transmission such that infection is easier between some species than others. Re filtering it out of the air: maybe. You can filter out any particle. I looked it up and found a volume for a [single prion protein](https://www.ncbi.nlm.nih.gov/pubmed/18445151): 30 nm^3. I was surprised it was so big; this is the same size as [polio virus](http://book.bionumbers.org/how-big-are-viruses/) and on the order of many others. Viruses are presumably made of many proteins so I don't understand how they can be the same size. In any case, you would need a good filter to get rid of particles this small. It would be slow going. [Answer] I suggest a highly contagious viral infection that damages the DNA and causes multiple forms of cancer. There is ample evidence of the virus-cancer link. In fact, the CDC states that > > Virtually all cases of cervical cancer are caused by HPV ([Human > papillomaviruses](https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-fact-sheet)) > > > The virus can have very mild symptoms and go away. Only a few months later, the previously infected person goes to the doctor and finds out that they have cancer tumors throughout his body. Finding the link between a very mild "summer cold" virus and this deadly form of cancer would be very difficult. The doctors would not be thinking infectious cancer and would assume an environmental cause. Only later, when the numbers of suffers dramatically increased would they realize it was spreading as an infectious disease. It would take quite a while to isolate the virus, and then years to formulate a vaccine (assuming that it doesn't mutate like the flu virus.) [Answer] A possible way to have the virus spread quickly yet be deadly is to have a double effect. Shortly after infection, it basically acts like the common cold. The common cold spreads quite effectively every winter, but is neither feared much nor do people take too strict measures to avoid it. So if in the short time frame, your virus is effectively indistinguishable from the common cold, it should have no trouble spreading. As the next step, it would take a strategy from the herpes virus: The herpes virus can hide for an extended time in nerves, invisible to the immune system, and not showing any symptoms, until it "wakes up" and gives symptoms again. Your virus could do the same after the initial common-cold effects. This dormant phase would make it harder to connect the activity after "waking up" to the previous infection, especially given the distinct symptoms (see below). I think about three months should be enough to obscure the connection. In the third step, after waking up it would no longer be harmless. Since it is already hiding in nerves, those would also be the obvious point of attack. Basically it could cause the nerves to stop working. A failure of the nervous system would certainly be deadly. If it doesn't come with other symptoms (especially without release of new virus particles), it would probably be hard to find a connection to the seemingly harmless virus. Of course after some time, someone will notice that those dying from that mysterious nerve failure syndrome all had an apparent common cold three months earlier. But at that time, many will already have been infected, and with the viruses hiding in the nerves, treatment will be hard, if not impossible. But of course there will be an attempt to at least prevent new infections. But here the virus could implement a strategy known from influenza and HIV: It could mutate its structure frequently. That makes it hard to develop vaccines against it, as any vaccine will only protect against the mutations it was developed from. As additional infection vector, it might also infect animals, however without those animals showing the deadly symptoms, so it goes unnoticed in farm animals which then get slaughtered normally. If the virus then survives cooking, eating meat could be an additional vector for infection. That would also make it harder to find the connection, because the meat-infected humans would get the nervous system breakdown without a previous apparent common cold,as the virus in the animals would already be beyond that phase when the meat is eaten. Thus would cast doubt on the connection between apparent common cold and nervous system breakdown, and therefore delay understanding, and thus fighting, that illness. [Answer] Could a virus stick to an oxygen molecule? Well, sort of, in the same way that an elephant could stick to an ant. It's certainly not going to be undetectable if someone is looking. An oxygen molecule has a chemical formula of O2. Uracil, which is one of the components of RNA, has a chemical formula of C4H4N2O2. And one uracil is nowhere near a whole RNA molecule, let alone a whole virus. But, it could be hard to correctly detect without being tiny enough to attach to single molecules. You found what appears to be a human skin cell in the air where this sick person is? That's about as noteworthy as finding carbon dioxide in his breath or white cells in his blood. People shed skin cells into the air all the time. ]
[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 6 years ago. [Improve this question](/posts/77686/edit) It seems that a human can't dodge a bullet once it is shot. That has been made rather clear by the articles I read. But is it possible (in a story context of course, I'm not trying this IRL :p) to dodge a bullet by looking at the direction the gun points at ? I'm currently thinking of this situation : Person A is that character. Person B can shoot projectiles with a gun-like tool at 200m/s (650fps), and stands at 10 meters of person A. Could Person A have good enough eyesight to see when and where Person B will shoot with human abilities ? With training ? With better than normal eyesight ? Can it ever be a 'reliable' technique or would it need really favorable circumstances ? First Edit : Or by using drugs ? I don't know if there's any that could temporarily improve your eyesight ? Second edit : Maybe I wasn't clear enough. I meant to say that A sees B pull out the gun and have the time to try to move out of the gun's way. Fifth edit : Okay let's be a little more specific than the fourth edit : would a close to zero reaction-time be enough to dodge the projectiles ? (and yes this is addressed in the answers) [Answer] The Mythbusters tested whether a human could [dodge a bullet](https://www.youtube.com/watch?v=2qY0DA7DG9s) from a sniper rifle. They determined that it was impossible in any real-world scenario. During preparation for the actual test, they identified their fastest reaction time, in perfect testing conditions, as 490 ms. With the setup identified in your question, the bullet will travel from the gun to victim in $$time=\frac{\text{distance}} {\text{velocity}}$$ $$time=\frac{10}{200}=0.05s=50ms$$ The intended victim would need to register the firing of the gun, formulate the idea to move out of the way, and send the signals to the appropriate muscles in one-tenth optimal reaction time for a Mythbuster and one-half the optimal reaction time [for the human species](https://www.reference.com/science/fastest-human-reaction-time-744b62945476fb5d). No pure human can do what you're trying to achieve. A human making use of some [handwavium](http://tvtropes.org/pmwiki/pmwiki.php/Main/AppliedPhlebotinum?from=Main.Handwavium), however, can most certainly dodge a bullet at any distance. In response to the OP's edit about dodging a gun being drawn: This will depend on how fast the shooter can draw. The world record for the [fast draw](https://en.wikipedia.org/wiki/Fast_draw#Sport) is 0.208 seconds, or 208 ms, but this is for the second shot fired in the competition round (less than 100 ms between shots). According to [these](http://www.defensivecarry.com/forum/concealed-carry-issues-discussions/130438-whats-good-time-draw-fire-1-round.html) [two](https://thefiringline.com/forums/showthread.php?t=355983&page=2) forums, a "good" draw-and-fire speed is within 1500 ms. So, in theory, the intended victim could dodge a bullet from a gun that is being drawn. However, once the victim starts to move, s/he is committed to the movement, while the shooter still hasn't fired and, thus, can adapt to the moving target. At this point, it just comes down to who has the better reaction time. [Answer] Anyone who is trained with a gun knows to aim for the center of mass (torso). While it would be possible to move in such a fashion as to confuse someone aiming for an extremity, it would not be possible to do so with someone trained to shoot at the center of mass. Assuming you are dealing with an untrained gunman, bobbing, weaving and zig-zagging would be enough to seem like your character was dodging bullets, and may even earn a reputation as being able to do such. But there is no actual "real way" to dodge bullets, even if you were extremely perceptive because you simply couldn't move fast enough to get out of the person's line of fire. He only has to move his wrist, or at most, his arm. You have to move your entire body. Edit added for third OP edit: No amount of equipment would help because the shooter himself would constantly be retargeting, so at best you know where the bullet was being aimed until he moved again. A better tactic would be to do something that would disrupt the shooter's aim, such as a displacement field (bending light to make you seem elsewhere) or something to disrupt the shooter's sight or equilibrium (flash or sonic weaponry) [Answer] Not without superhuman abilities. It would be more believable then outright dodging bullets. But no a human would not have the eyesight nor the speed to calculate the exact aim of his opponent. In regards to drugs, no. It isn't just your Eyesight that is lacking. It's the ability of the brain to calculate the trajectory of the bullet from the barrel. And after that still have the time to move out of the way. Drugs will not get you there. And even if you could you run into another problem. The speed of your neural network between your eyes, your brain and your muscles. Even if you know after your opponent points the gun where the bullet will hit. You still need to tell your body to move. Your fastest nerves seem to be capped at about 120 m/s. Thta's not all of them, that is the fastest. Others only send at about 30 m/s. Your human body is simply to slow. [Answer] > > Concerning the tools A has, I didn't think of any in particular, but > you can put it if it's something that could technically be made > nowadays and be easily portable (like the AR-headset to help predict > in what direction the gun will shoot). > > > It's not detection that's the problem, it's reaction time. Car air bags have similar reaction times. So, bullet-dodging armor would be a harness attached to an incoming bullet-detection system. When bullets are detected, the harness could use explosive charges to move the wearer out of the way. And then call for medical assistance, because getting moved like that is going to feel a lot like getting clubbed. People saved by airbags often have broken bones. Still, I'd rather have a stroke than take a bullet to the head. Edit: Oo. What about an AI monitor that can watch the faces of opponents to know when they are going to fire? In this case, all the harness has to do is anticipate their aim corrections and defeat those. You end up walking like a drunk guy as bullets pop all around. [Answer] The best you can do is detect the tension at the hand and forearm muscles when he attempts to shoot you and moving away half a second before the trigger is pulled. [Answer] Based on the other answers, it sounds like human nerves are the limiter here. If you're willing, your protagonist could have undergone some procedure (think riddick eyeballs), but relating to their nervous system instead, letting them react faster than other people are able. Perhaps then they'd be able to dodge bullets, and also potentially some other cool stuff that I can't think of right now. [Answer] In a highly futuristic situation you may invent something to make is possible within some realistic bounds. You could have your Person A wear augmented reality enabled contacts or glasses, which in his field of view constantly keeps him aware of the surroundings and may possibly notify him that person B has I'll intentions, or if they're already in a standoff even better... The AR will focus his attention on Person B. Looking at the attitude, expressions and movements of Person B, the AR would then warn Person A to get ready, he will be shot. As Rekesoft said, it will then look at the muscles of Person B, and identify the type of gun to assess at what point the trigger will go off, and then at the right moment tell him to jump in the optimal calculated direction... This situation assessment may give Person A a few more seconds to mentally prepare himself for this situation buying a few extra milliseconds of reaction time. Keep in mind that the assailant may obviously be trained in fooling these kind of systems though... ]
[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/77646/edit). Closed 6 years ago. [Improve this question](/posts/77646/edit) What would be the best way to permanently increase a human's speed, strength, stamina, and durability? I'm looking to create a world in which the majority of humans realize how weak and feeble their bodies actually are and they have found a way to change this. However, I need help on the actual "way". I'm not scientific at all but I don't want to be cliche by giving them a serum or a pill. I was looking for something that would require surgery. The use of some sort of technology would be ideal but it is not absolutely necessary. [Answer] At least for stamina, you could read up about "the man who can run forever": Dean Karnazes (<https://www.theguardian.com/lifeandstyle/the-running-blog/2013/aug/30/dean-karnazes-man-run-forever>). Karnazes' ability to run for inhuman distances seems par for the course with other endurance athletes, but what sets him apart is that he honestly does not show signs of muscle fatigue AT ALL. The article explains it all, but if you want a quick summary, here it is: Basically, your muscles send out fatigue signals when lactic acid builds up from anaerobic exertion - this is when you begin to feel tired. For Karnazes, his body clears lactic acid so efficiently that his muscles never send such signals, and thus he never feels tired. As such, he can basically keep up a decent running pace for as long as he can stay awake. How does this relate to your question? Imagine that you were able to create some nanobot with the ability to metabolize lactic acid. Inject this nanobot into your subject, and voila! He now has superhuman stamina. [Answer] The thing to remember is that every attribute comes with a cost. Cheetahs are fast — but they have almost no fat reserves, and not much of anything else. Race horses have been bred to be really fast — but are always on the edge of breaking legs by overdoing what they do best. For humans — muscles consume a significant amount of our food resources, even at rest. That's why they atrophy very quickly if not used. Our big brains are supposed to be useful (they've allowed us to conquer the whole planet) but use about a third of the calories we consume. Plus, too strong, you could break bones or dislocate joints. There's a very good [short story by Larry Niven called "Brenda"](http://news.larryniven.net/biblio/display.asp?key=209). It discusses the problems with breeding super warriors — double gene for night vision causes daytime blindness, doubled gene for blood clot (stop wounds bleeding) leads to blood clots and stroked by age 40 or 50. And so on. The fastest are rarely the strongest; pick one or the other (look at the Olympics). Plus, human scale is designed for the size we are. Bigger, taller, or carrying a bigger load means thicker bones meaning slower running. Unless you're looking for some magical formula where the muscles operate say, 20% more efficiently. [Answer] The same one that works now, exercise and training. If you want to make your new human more fit, just make them enjoy exercise more than normal humans. Minimal changes to the human, just a few changes to the initial wiring of the brain, and it can be spread organically(breeding) or artificially (genetic manipulation). If going to gym was as pleasurable as going to the strip joint, bar, or dunkin donuts you would have a stronger, faster and more fit populace. [Answer] I imagine that you could use implanted stem cells to increase muscle mass, as these cells will usually change into whatever kind of tissue surrounds them. This solution would improve speed and strength. By combining stem cells with genetic modification you could theoretically create entirely new organs to implant in a human. This isn't even too far fetched based on modern science. The genome editing molecule known as CRISPR-Cas9 is relatively new, but allows scientists to splice DNA from different organisms together with much more specificity than was ever previously possible. With this technology you could give people bird hearts and lungs (which are much more efficient than mammals') or something even more amazing. If you want more inspiration, I recommend looking through this link detailing the process to create a Space Marine in the Warhammer 40,000 Universe. [Creation of a Space Marine](http://wh40k.lexicanum.com/wiki/Creation_of_a_Space_Marine) They have extra hearts and lungs for added stamina, and they take dietary supplements which add different minerals to their bones for more durability. [Answer] # Get Rid of Chemical Energy Muscles are simply polymers. An electrical signal tells them to wind themselves up (contract) or unwind (relax). They're not very good ones either, but they've got an amazing amount of control, ultimately using a chemical as an energy source ATP -> ADP, and generating a waste product (lactic acid) for this energy conversion. Overall it's messy and irreversible, which causes the non-linear strength, speed, and stamina problems. The reaction rates simply can't happen fast enough for all three to be increased simultaneously. ## Using Electrical Energy By converting to [Electroactive Polymers](https://en.wikipedia.org/wiki/Electroactive_polymers), a type of artificial muscle, the waste product is simply the drop in voltage. Stamina is unlimited - so long as you have an electric source, you're muscles keep working. Does your laptop complain "it's tired"? No! It complains it's battery is out. So long as you have futuristic energy storage, this isn't going to be a problem. To add strength, increase the voltage. To add speed, increase the current. If you have limited energy storage, increasing one of these will necessitate decreasing another. But with unlimited energy, then all three could be enhanced well beyond human limits. [Answer] Cyborgs then, requires technology and surgery. Your weak arm muscles? replaced with basically a nanoweave of hydralics Bones? Bah we use titanium They can be powered both by electricity/converting fat/stealing energy from the digestive tract. Another route would be to simply have worked out a more efficient cell structure/ biological processes, a more efficient way of binding oxygen could improve the supply of oxygen to the cells etc. There are many inefficiencies in the human body that could be improved upon. [Answer] You could make them really big, like giants, and hope that it would scale these stats up - they'd be faster because their legs would be longer, more durable because things wouldn't hurt them as much because "oh it's just a little scratch", and they probably wouldn't need as much stamina - but they'd need to eat a lot more to sustain their huge size. [Answer] A very permanent way would be altering the human genetic code. Not only would this alteration enhance the human you first use it on, the change is going to remain evident throughout the rest of their descendants as well. We already use genetic therapy on foodstuffs to increase their quantity and quality. Genetic therapy already exists for humans and involves inserting genes to fix problems instead of drugs or surgery. For some genetic conditions this is the only course of action that will succeed. In the case of humans you would find desirable traits and locate the code that works with these traits. For example, once all code related to metabolism is understood, you could change the genetic code to ensure a person gets the most out of every meal they have with little waste. The most realistic method would be to simply remove any and all defects that will possibly transfer via genetics or bloodline. History of heart disease? Wiped out. Genetic disposition for astigmatism? Wiped out. You'll be able to undo or prevent an assortment of problems from ever occurring. This does open up the potential to have an ugly backlash though, an unforeseen issue that might arise with the tampering could be difficult to fix, and it's not something that will just go away either. A better way to look at it would be the ability to have the maximum human potential. You'll still have to act on it. The greatest genetic sequence in the world won't make a musclebound monster of a man if you never exercise or pick up weights. (I've never given an answer before so sorry if this does something wrong) ]
[Question] [ ## Setting: Earth-sized planet, its inhabitants are human settlers and live in [towns](https://worldbuilding.stackexchange.com/questions/39775/space-wizards-city-is-it-sustainable) protected by custom-sized atmospheres. The rest of the planet is barren and always was. The population uses the equivalent of late 19th century technology, except with machines powered by magic and no access to petroleum. Their agricultural resources are restricted. Not that the people go hungry, but they can't afford to mismanage their cultivated lands. They practice fish farming, but don't have domesticated animals bigger than a duck. Because of the setting, it would be impossible for these people to synthetize designer drugs, or to produce enough grain or fruit alcohol for mainstream consumption. --- For plot purposes, I need this world to have recreational drugs. --- I'm trying to find one or several drugs that could fit these uses: * In social gathering, a light consumption helps people socialize and have fun. Consuming too much would lead to stupid behavior and/or some physical symptoms like vomiting or passing out. * Either an overconsumption of a social drug or the consumption of a harder one creates a strong addiction and takes a heavy toll on a person physical and mental health. * One drug can be consumed regularly without major adverse effects, like coffee. If this one is impossible, I can work with "trace amounts of drug X is present in a common drink or food". Also the plants or animals used to produce them where brought from Earth to this planet. For now I chose to make [psychoactive mushrooms](https://en.wikipedia.org/wiki/Mushroom#Psychoactive_mushrooms) the most common recreational drugs, because they can be cultivated in small spaces and relatively short amounts of time. Other possibilities include marijuana (cultivated indoors), psychoactive toads (not sure how to make this one work) and some sort of cactus that could be grown in the wastelands. --- ## Question : Given these people resources, and leaving the legal questions and the government's stance out of the equation ; ## What recreational drugs could be produced and consumed in this setting? [Answer] Largely synthetic drugs like MDMA and methamphetamine simply require the base components and pretty simple laboratory set-ups. Meth labs in particular can be VERY low tech. But since you specify a 19th century tech and include "magic", it seems unlikely that most of the base ingredients will be available in a refined form and since very drug, I believe, ultimately has some sort of organic component it would require the colony to cultivate that plant/fungus to extract that initial compound. Huffing chemicals, like nitrous oxide or aerosol propellants is a possibility, but again, I'm not sure 19th century tech would have much of that (they seem to be drugs of absolute last resort). Plus many of these compounds have a petroleum-derived base and if your world is low on natural gas/hydrocarbon energy that would be problematic. So what colonists are VERY likely to take with them are poppy seeds, possibly coca seeds, tobacco, and absolutely hemp and marijuana seeds. These plants have substantial medicinal value, particularly anesthetic which is vital for the practice of modern surgical technique. Hemp has numerous commercial byproducts and nutritional value, so it seems likely that THC containing varieties will also be included. Tobacco is a luxury good, plus it has nicotine, which has substantial value as a stimulant. There will undoubtedly be some sort of grain or spirit generating starchy plant (potato, rice, wheat, corn, etc) which can easily be fermented with simple yeasts found in the environment (or brought with them in freeze dried form). Alcohol has MANY uses, from sterilization, sanitation, and industrial, besides the intoxicant effect. Even if the colonists EAT the grain, there is usually enough residual sugars in the non-edible portions to allow for fermentation. This is a necessary thing, since an alcohol based liquid is a valuable way to store food energy that otherwise would be lost to rot/pests. Perhaps in the colony there is a year round growing cycle, but you can't just dump grain into a silo forever for storage. Making beer/wine/spirits is a way to retain at least some nutritional value. Pure psychedelics like mushrooms are a little more questionable. They have a long history with religious practices though, so it seems likely that some would be brought with the colonists. Really though, unless your planet is totally sterile, it seems pretty likely that, given enough time, some enterprising experimental pharmacologist or chemist will find native compounds that have a desirable (though possibly long term deleterious) effect on human physiology. Even toxic compounds, if refined in some manner, can be rendered somewhat safe for human use. There has to be local sources of hydrocarbons in some form, else the entire colony would have to be recycling ALL of their carbon, which seems unlikely. These chemicals can be refined into substances that have effects on humans, if only for huffing (which is a really bad way to get a high). [DMT](http://www.wisegeek.org/what-is-dmt.htm) is a likely drug. It is present in damn near everything, but it needs some processing for it to be effective. Seems like it is highly ritualistic, so I'm not sure how well it would go over at parties/social settings, but it seems fairly easy to produce. Worst case is something like oxygen deprivation paired with VR, sensory deprivation tanks, [ASMR](http://www.vice.com/read/asmr-the-good-feeling-no-one-can-explain), or the like, basically a non pharmacological method of altering perception. EDIT: If you want some inspiration on all the different ways humans have managed to generate alcoholic drinks out of damn near everything, I recommend Amy Stewart's [Drunken Botantist](http://rads.stackoverflow.com/amzn/click/1616200464). It is a fun read and very illuminating about all the different ways humans have managed to get drunk. And really worst case, your colonists could use [Jenkem](http://www.snopes.com/crime/warnings/jenkem.asp) :P [Answer] Alcohol still meets your requirements and is almost certainly going to be the drug of choice on your planet. It meets all of your bullet points. Alcohol is extremely easy to produce, useful in a variety of other ways, and addictive. Your planet is bound to have some people that take their food and ferment it into alcohol and then either share it out or sell/trade it. There may be no centralized alcohol production industry but that doesn't mean people won't make a large amount when taken as a whole. A plus is that fermentation, in general, is used to prolong the shelf life of foods or make foods more nutritious by making the nutrients in the food easier to digest. [Answer] [Huffing carbon dioxide](https://www.erowid.org/experiences/exp.php?ID=62943) would require virtually no resources. Essentially all you need is a sealed bag to continuously breathe in and out of until remaining oxygen has been mostly replaced by CO2. The effects come from oxygen deprivation, and are dangerous, and likely very uncomfortable. Depending on the social state and general stress of this society I believe it could conceivably fit all three of your requirements, especially in the abscence of other drugs. It would not be physically addictive, however, the addiction would have to be psychological. I would say this population was in desperate times if this became their high of choice. --- As an aside, if you can get ammonium nitrate, a more comfortable experience would be nitrous oxide (whippets), which can be [produced with minimal resources](http://chemistry.about.com/od/makechemicalsyourself/ss/How-To-Make-Nitrous-Oxide-Or-Laughing-Gas.htm) as long as you have a heat source, water, and various containers. I don't know how to produce ammonium nitrate as resource-free as possible. It is naturally occurring in certain minerals. You could continue down through [e.g. this process](http://chemistry.about.com/b/2010/05/04/make-ammonium-nitrate-from-household-chemicals.htm) until you find things that occur in your environment. It's also used in fertilizers, which may have been brought from Earth, which could lead to an interesting dynamic where food sources that relied on the limited quantity of fertilizers were sacrificed in lieu of making drugs instead. I can say from ... let's call it second-hand experience ... that whippets meet your requirements in at least some form. They certainly decrease the productivity of a community, that I can say for sure. --- Along those lines, basically anything that replaces oxygen, is not directly toxic (like, won't just kill you immediately), and ideally tricks your body into thinking you are breathing properly (e.g. nitrous oxide, doesn't cause pain like holding your breath does with CO2, hence its high recreational use), would do here. --- Also, is [raising bees](http://www.almanac.com/blog/beekeeping/beekeeping-101-why-raise-honeybees) feasible if an initial population was brought from Earth? Their honey combined with a batch of yeast from Earth as well can produce mead, which of course nicely meets all of your requirements. The bees would be sustainable, and the yeast would be sustainable for a few generations at least. You may be able to put the first generation of yeast in stasis with your magic, and use that to re-seed periodically. [Answer] The drug of choice in Victorian times, may I present [Ether](http://www.history.com/topics/ether-and-chloroform)! It does for what ails you! it's clear and odorless, highly flammable and gets you as high as a kite. The [preparation](https://www.erowid.org/archive/rhodium/chemistry/ethyl.ether.html) is very simple in comparison to other methods. In order to produce ether you need alcohol, for alcohol you need sugar. How about they harvest local produce, extract the sugar and ferment it down. The local flora doesn't need to be edible, just contain sugar. [Answer] In the middle ages people made bread with rye. There's a fungus which grows on rye called ergot. It's lethal in high doses, but in small doses it'll just make you sick... and high as a kite. It's a powerful hallucinogen. People discovered that if you rubbed the substance against permeable skin, like armpits or genitals, you wouldn't get sick, just have a good time. Often manifesting in feeling that you were flying. Which is actually where the witches riding broomsticks meme comes from. [This article](http://www.theatlantic.com/technology/archive/2013/10/why-do-witches-ride-brooms-nsfw/281037/) covers it and associated cultural-historical connotations. So that's definitely something that you can do with limited technology. There's also something I heard [regarding reindeer](http://www.huffingtonpost.com/2010/12/23/reindeer-magic-mushrooms_n_801006.html). The nomads who lived in northern Siberia, if I recall correctly, noticed that there was a toxic mushroom that reindeer ate, and then the reindeer behaved like they were drunk. So, ever curious, the locals decided that owing to the mushroom's toxicity, the best way to handle this safely was to collect and drink the reindeer's urine. Basically, toxic mushrooms filtered or diluted somehow seem to be a very cheap and low tech way of getting off your face. [Answer] In order to optimise the effort put on drug harvesting, I suggest to focus on drug with heavy effect and mix them with food/liquid. Thus, you can have large amount of drug with little quantity to grow (for example, a single toad can be infused with several litters of water (like tequila) and last for a month. Then, you can also use drug who don't need attention and dedicated land to grow. For example, mushroom can grow in wood or among crops while marijuana need to be watering and occupy more place. [Answer] DMT is an astonishingly common and powerful hallucinogen. Many, many animals in their death throws experience a natural DMT trip. When people go through a near-death experience and say things like they had "gone towards the light," DMT is taking them there. People aren't so sure why this happens. A prevailing theory is that the DMT trip help eases a dying brain into acceptance of its own fate. Some believe it is a gateway to other dimensions of existence. So, given that the supply is abundant, the question becomes a matter of extraction. OP said the society practices fish farming, so if the magic is capable of extracting DMT from the slaughtered fish at the time of death, then the preparation of meat could also double as a religious ceremony, whereby the meat is extracted to feed the body and the DMT is extracted to feed the soul. Perhaps this is the way their society "balances the books" from a subsistence driven by the consumption of flesh. [Answer] [![enter image description here](https://i.stack.imgur.com/qFfNT.gif)](https://i.stack.imgur.com/qFfNT.gif) If magic is a thing, then magic will influence the environment. Be it "Dust", material from outside (the sterile rock and/or literal dust) which is magically affected and thus can have some effect when taken into the body directly (topical/ingested/inhalant)or indirectly (used in food, drink, or other product preparation). The plants and animals brought along may also have been affected, if there are no domesticated animals larger than a duck, then breeds of dogs, cats, and birds are all on the table... perhaps literally if there is no other source of meat (are livestock not consider domesticated animals?). Whether altered by the magic, or perhaps prepared with magic, some organ or other edible part or byproduct may serve as your social lubrication. (Person one: "This drink has a nice kick and buzz, but tastes like cow piss! Person two: "Well....") Spells as entertainment or intoxicant is also a possibility once magic is available. Any party may inherently or naturally (or artificially if unconscious magic is not a thing) have a ritual component which invokes "cheer and goodwill" and leave all participants with that buzz that some find pleasant. One might even find the occasional rude/violent drunk who is more susceptible than others to the effects. It could even be an outright spell that is cast before the heroic feast. ^^ [Answer] Nutmeg, do they have access to smoking nutmeg like pirates did? Strong but easy to OD on so do NOT try this at home. Are their industrial solvents or gasses to huff? Morning glories, the common flower, is also smokable, can they grow flowers? Alcohol can be fermented from food waste/scraps, what do they do with their garbage/compost? Do they have stale bread, you can make beer from a stale loaf. On that note, you can research Jenkem and see if that was a hoax or possible. What do they do with their dead? Access to formaldehyde? [Answer] Dude, Hemp, dude. Grows like weed, even on terrains otherwise little suited for crops. You know what to do with the leaves. Stems are very useful as a fiber source for textile and ropes. [Answer] It seems that your main problem with plant-based drugs is that settlers cannot waste fertile lands on it. But in reality you cannot grow single crop every season, it will have adverse effect on soil. To avoid that you will have to [rotate crops](https://en.wikipedia.org/wiki/Crop_rotation). And do you know what common rotation crop was? Hemp, member of genus Cannabis. Its relative is Humulus, more commongly known as hop. So fields, which temporary cannot grow main crop will produce plants for brewing beer and making pot. [Answer] You sad they cannot harvest much crops, so I assume they cannot waste land to cultivate herbs and fungus, those would be relatively easy drugs to obtain. However nothing prevents them from consuming drugs that grows spontaneously. Event better, they maybe HAVE to destroy marijuama because is a infesting weed ( in reality that is extremily plausible, countries that cultivates marijuana are basically going to become deserts in 1-2 decades) that is destroying all crops, so much of they work is simply destroying marijuama and as side effect they smoke a bit too. Another relatively simple drug to obtain are ~~oil~~, painting and glue (some people just smell/drink those extremily toxic and cancerogen compounds). Everything added by other answers is still good for your plot (~~alchool~~, MDMDA, methamphetamine) [Answer] How bout some good Ole peyote ,belladonna, glue or spray paint inhalants, chewing cocoa leaves or the liquor natives make from chewing plant and Spitting? Or a virtual reality head gear kinda like an opium den. But the kind of high you get depends on your core beliefs and characteristics....man,that could give you endless story twists and possibilities! Valerian root no special storage ]
[Question] [ One fine day, magical space aliens arrived and launched and harpooned an extremely long(100,000 km) and thick(100km radius) spear into somewhere in equatorial Africa, which buried and anchored itself via large barbs. It penetrated 3000km into the Earth. The aliens then left as mysteriously as they arrived. The spear is made of an alien material, and is indestructibly strong. Efforts to cut out pieces of it for testing or used in any other way has been completely useless. The spear is also clearly strong enough to support its own weight despite its hugenormous size and presumably weight. A group of philanthropists, including a Elon Musk-expy and Bill Gates-expy then walks up and buys the land surrounding the spear and the spear itself, and they plan to use it as a foundation to build a space elevator. What are the problems that will be faced for the philanthropists in their efforts to bring space to humanity, in terms of politics? How difficult might it be for them to be able to procure the spear for themselves, or might the government not allow it? Would the country in which the spear landed in be able to have full claims to it? Notes: * The Spear, being a spear has a grooved grip the entire length of the shaft, which allows for things to be attached to it. * The Spear is practically massless. They can't really check if it is actually massless, but nothing too terrible happened * The Spear is indestructible, it was magic space aliens who placed it there, after all [Answer] Using Newton’s penetration formula, $$\mathrm{Depth} = \mathrm{Length}\dfrac{\mathrm{Projectile\ Density}}{\mathrm{Object\ Density}}$$ We can find out a lot. The mantle is where most of the rod will be. The mantle’s average density 4.5 grams per cubic centimeter. $$3000\mathrm{km} = 100000\dfrac{\mathrm{Projectile\ Density}}{4.5\mathrm{g\ cm}^{-3}}$$ Solving, we get $$3000\mathrm{km} = 100000\dfrac{0.135\mathrm{g\ cm}^{-3}}{4.5\mathrm{g\ cm}^{-3}}$$ The volume of the spear is about $3.14 \times 10^{42} \mathrm{cm}$. Solving for mass, we get $4.239 \times 10^{41} \mathrm{g}$ or $4.239 \times 10^{39} \mathrm{kg}$. This is heavy. Its mass is very large. $g = 9.8 \mathrm{m\ s}^{-2}$. I will spare you the boring math, and tell you that when it hits, it is going at $9129 \mathrm{m\ s}^{-1}$ at least. This is a spear, heavier then the earth, going at Mach 29. The earth definitely won’t be worrying about ownership rights any time soon. [Answer] The country in which the spear is buried does indeed have full legal rights to control it, with the limitation that it's not clear how high their control extends. National control of airspace follows traditional legal guidelines, but vertical limits are not legally extant. Since no country (to date) has protested satellite overflights, a de facto limit of about 100 miles is probably a safe guess. And it could be less, since force is the coin of sovreignity, and if a country cannot enforce its claims it's pretty much out of luck. An organization such as the UN might conceivably claim possession of The Spear ("in the name of Humanity"), but would be hard pressed to put together a military force to take possession of it. And, as a complicating factor, I can't imagine a 100 km diameter object burying itself 3000 km deep would not devastate the surrounding countryside. This would cripple the national government, and as a group the equatorial governments aren't in all that great shape anyways, particularly the African ones. [Answer] There are some very expensive meteorites that fall on earth and can reach some million dollars price. So, most countries are divided between full ownership of the space object by the state or full ownership by whoever citizen happens to find it first. But, as the object is stated as being clearly the result of alien intervention, i believe the principle of national defense and sovereignty would ditact that such object will remain under government control. Regarding such objects - alien objects that are intentionally launched into earth - theres no law nor international treaty. UN does not even recognize the existence of Aliens. When there is no international law, states hold full sovereignty over their territory and claims, and things might very well end up being solved by the force of arms. So, this object will most certainly be retained by government control, until its cleared as safe, not possible to reverse engineer etc. It might be sold to private ownership soon afterwards. I dont know. Regarding airspace, theres a international treaty that sets the limit of a country airspace into the threshold of the space. At 100km height, on the Kármán line. This same treaty stipulated satellite slots to be distributed among all countries etc. I dont remember the name of the treaty (or treaties). So, in the event that this object protudes more than 100km above the sea level, it might be considered inside international space. This is a very strange situation indeed and everything that is said is pure speculation. Satellites circling around the globe are inside international space yet their ownership is not usually questioned. But, one can argue that such satellites were made in the owning country or on another country on behalf of the owning country/company/person, while this object was launched from outside space and part of it never fully entered sovereignty areas of the country at hand. It might be a new kind of superweapon endangering the very existence of humankind etc. So, whenever your international treaties are open to debate, the usual result is: Mighty makes right. You will end up with someone talking in CNN on how the marvellous United States of America, the land of the brave and the country of the exceptionalism has the right to take over the object, even bombing some terrorist threats that want to hinder the path of human development, democracy and liberty bla bla bla. UN security council is unable to reach a consensus with China sitting over the wall etc. Usual international politics, you know. Some ten years later a new treaty dealing with ownership of alien objects launched on earth is being signed to avoid wars due to the lack of clear laws and treaties about this matter. Later elon musk and bill gates are subcontracted to develop a space elevator using public funds and earn some trillions of dollars out of taxpayer pockets, or if bankrupt they are saved by a government default. Business as usual. [Answer] I hate to spoil this one, but Bill Gates likely won't exist after this thing hits the earth. As Jimmy360's answer says, if the spear truly is a projectile, it will hit the Earth at Mach 29. That impact will cause: * a huge crater * lots of huge earthquakes + lots of also huge tsunamis * many deaths It will likely be decades before everyone has recovered enough to even think about investigating the spear. However, there is an alternative. If you use the spear not as a projectile, but as a giant mining drill, the effects are less. Essentially, the spear should drill its way into the planet - then it doesn't need to be going at such insane speeds. With this method, there is still going to be lots of damage, but investigation could start a lot sooner. The spear would be under the control of the government of whatever country it lands in. However, without wishing to generalise, lots of African governments are corrupt and could likely be swayed to give control of the speared zone to someone else with lots of money. Which is exactly what Bill Gates has. To actually make the space elevator, since the spear can have things attached to it, they can attach strong steel cables and run an airtight elevator up them. [Answer] [Can you adjust the size a little to be more pragmatic please, say 500mm to 50m diameter, 1km to 50km deep, 100km (edge of space) to 46,000 km (just below geosync) in height.] Going back to the key part of the question, what happens next! It exists, and two or more powerful people/companies/organisations/countries have access to it so no monopoly, and no war. First the tech would be sorted to provide a movable platform that would get payload up and down with little or no weight constraint. That allows space ships to be built and fueled in orbit, and that allows the exploration and exploitation of space. Making it possible to mine the asteroid belt for raw materials and using high efficiency solar panels for energy, you could have low gravity manufacturing plants in orbit. Everything from cars to pop-corn would be cheaper to make when you don't need the energy to overcome gravity. Ion type drives would replace rocket motors and without the near earth gravity well to deal with, the weight of radiation shielding stops being a blocker to long haul missions. The irony would be that the alien 'gift' would allow us to travel to other worlds in person, but we couldn't do anything when we got there because we still couldn't overcome gravity wells. [Answer] I think the Earth must have slipped into a dream universe where physics doesn't apply. In particular, even if this object is somehow "practically massless", since it is enormous and indestructible and embedded deep in the planet, in a universe with semi-normal physics, it matters how heavy it is, and whether or not it interacts with gravity at all. In any case, I don't really see any possible answers to such questions, which would result in it continuing to stay in place relative to the spinning, orbiting Earth. It will either sink in or pull out, and it will also twist, causing ridiculously enormous earthquakes and magma eruptions, which as others have pointed out, would also have almost certainly destroyed all life on Earth. Even if something survived the earthquakes and vulcanism caused by the insertion, even less will survive when the thing rips sideways through the crust, and/or out the far side. So... the good news is, you're in a dream dimension or comic book or anime or something, which is ignoring physics and making it stay like that, for now. Even if the mass replaced by the spear when it inserted somehow vanished, it will now have some pretty interesting weather effects around it, as the atmosphere will flow around it. Politics? Ownership? Well that's all speculative. Probably there would be many hypotheses about the aliens and why they put it there. "Hey, let's make it into a space elevator and profit" might eventually be a conclusion after nothing else weird happened for a long time, though there might be another popular point of view saying, "hey, let's not mess with it as clearly the aliens who put it there might not like that, it defies all physics, and who knows what the heck will happen if we do that?" Maybe people would use its African location as an excuse to keep it neutral and not allow anyone to unilaterally seize access. Maybe the local nations would try to get the best bids they could. Realistically, Earth politics has become a puppet act of a group of corporations who own most of the world's wealth and bought officials anyway, though, so any such story would really likely be invented by or actually controlled by such organizations anyway. Perhaps they'd decide to capitalize on space, and develop a new giant industrial complex around the site. But since we've already proven this must be dream universe, really anything is possible. [Answer] I'm going to play the optimist and for the sake of this exercise lets assume the device, with or without immediate major destruction to the planet, was in place and the smoke has finally settled. Humans are now faced with the fact they are NOT alone in this universe. A realization that most, if not all, of their fundamental (geocentric) beliefs are shattered and will put aside their cultural hate / breed distaste mind set for each other to work as a single species and no longer as many nations. If the artifact did major damage to the planet humans would most likely decide to quicken the pace to get off this mud hole and start to colonize at least our solar system. An estimated price tag for an Earth elevator is 6 billion to 20 billion USD using a Nanotechnology that still needs improvements due to current length manufacturing limitations. <https://en.wikipedia.org/wiki/Space_elevator_economics> However the aliens just gave humanity a shortcut and since we no longer need the strength of a single nano-tech tether we can use existing tech such as nano-steel for platforms and tracks. <http://www.technologyreview.com/news/534796/nano-manufacturing-makes-steel-10-times-stronger/> Seeing as we have the tech to build a Lunar elevator, bridging the gap between the two rocks would quickly follow. [What would a space elevator on the moon be made out of?](https://worldbuilding.stackexchange.com/questions/27019/what-would-a-space-elevator-on-the-moon-be-made-out-of) Were I a philanthropists leader of the liberated world, I would commission our best to fit super conductor train tracks and power transport by electromagnetism. Powered by the huge space array of solar panels or the nuclear power station bases located at a safe distance from orbit. Or perhaps the generators that use solar winds to function. Second Scenario If the world politics stay the same for the most part and the philanthropists have difficulty with the politics surrounding land grab attempts of other nations it may be necessary to convince the majority of the world (the 99%) how unrestricted access to space will enrich and enlighten our species and increase our odds of survival. If that doesn't work there is always the scare tactic that we need to be ready for when the aliens return and only we know how to defeat, defend, communicate, etc, with them. With the resources our philanthropists have there is no doubt that a unifying message can be transmitted to the world and the people would rise and make a change. Perhaps a mass migration to join the philanthropists new nation leaving their countries of birth. Our philanthropists should have no remorse using their resources to build an army for the betterment of humankind. (Federation of Inner Sol Planets.) If the event were destructive enough and perceived as an alien attack it wouldn't take much for an entity to manipulate the majority to unite under their flag for security. The area around the space needle would no doubt become a hub of technological advancements and the center of any world power to which the philanthropists should be able to sway in their favor. *Celebrity, Propaganda and Financial Resources go along way to building a political following!!!!* ]
[Question] [ This is my first post so please be patient with me. My issue is this: I am designing a world in which there is one chief creator god. In order to make the tasks of running the plane less taxing he created five angels to be aspects of his will and govern the mortal races. I want to design this as a world to run multiple RPG campaigns in but I am worried about the limiting player choice with regards to divine domains. Do you have any ideas how I can account for player choice of an ever growing selection of divine domains (currently ~14 in D&D 5E) while still maintaining the limited pantheon? Thanks for the advice. [Answer] Your divine beings are the same, but don't always look the same or act the same. When analyzing different religions with a pantheon of Gods and mythical beings, you can easily see one noticeable thing: more often than not, these gods represent different natural events, occurrences characteristic to their respective societies and other phenomenon. A rough example: what does The Egyptian God Osiris, the Mayan deity Camazotz and the Greek God Thanatos had in common? They all represent the event of death, despite each having their own motivations, personality and goals. Similarly, much how the Greek gods were depicted as having several human like traits, nothing stops an eternal being from changing the way it sees the world in a temporary or permanent way, much like we will wake up one day calmer than a sleeping lamb while the next day we might want to punch the first face that appears. Your deities in the 4th campaign are the very same that those in the 1st, but be it because they themselves changed or because we changed the way we perceived them (or both), you might find completely different cults and religions which in fact adore the exact same beings, with the difference that each of them adore certain traits of their beings either because the being in question changed how it showed itself and their view on the world or simply because with time the being was just seen in a different way, and reacted to the peculiar adoration with a "sure, why not?". The Egyptian goddess Sekhmet, for example, was simultaneously the goddess of war, of the sun (despite Ra being the main deity in this aspect), of cure and of disease, so it's very easy to picture 2 cults: one which would adore a similar entity due to them representing the goodness of the sun's blissful light and the cure of illnesses, while the second one adores the same entity due to them being the deity of disease and war, which foment chaos in society (the deity controls all of these, they also like extra attention, and nothing is stopping them from also deciding they'll share the title of God of childbirth with one of their immortal pals in a later date). In the end:if you want many campaigns to happen in the same world, the key is to make things a little different every time, and I'd say one of the best way to keep you pantheon fresh is to have its members also change their views and behaviors in response to the ever changing world they rule over. [Answer] This seems like a non issue, really. In most polytheistic religion there were gods who ruled over different domains and even gods who started taking over new domains as they go, either by creating it or taking it from some older less popular god. Artemis, for example, was not only the goddess of hunting, she was also the goddess of moon, childbirth and to some extent even fertility and nature. Her brother Apollo is more famous as a god of medicine and art, but he is also associated to death and plagues, sailor, the sun, nature and reason. Poseidon was a god of the seas to the greek, but to the mycenaean before them, he was the god of the underworld. In short, is not a problem to have few gods, the petty mortal would associated whatever they want to worship with some of the existent gods, or even with multiple gods at the same time. As for why these domains are separated despite belonging to the same god, it is because our petty mortal brains are not able to worship the divine in its entirety. Sure, nature is handled by a single god, but to our petty brains fertility, vicious predators and sea storms are VERY different. So the domains don't come from a limitation imposed by the gods, but by the mortals themselves in order to separate the divinity into small worshipable parts. [Answer] ## The Many Faces of God in the real world, there are three major religions, and seven "other" religions (according to [wikipedia](https://en.wikipedia.org/wiki/Abrahamic_religions)) who all worship the same God and all descend from the same core faith. however, they all favour different scriptures and disagree on many aspects of their faith to the point of war. Even very closely related faiths (Shia & Sunni, Catholic and Protestant) have had bloody disagreements even though they are more closely related than other Abrahamic faiths. If your world had even a simple form of this for each of your divines, then you would have plenty of different faiths to choose from. [Answer] ## When the Saints Come Marching In: Rather than have more gods, why not have multiple denominations? Christianity has managed to splinter itself quite nicely, as has Islam, Buddhism, Hinduism, etc. All espouse a sort-of core system, yet you can have Mormons and Jehovah's witnesses alongside ELCA Lutherans and Gnostics. To use Artemis, from the previous example, In Greece she was an (officially) asexual goddess of the elites, but when morphed into Diana in Rome, she was considerably more tolerant of commoners and at least some of the belief systems clearly suggested she was a Lesbian. Further, you can have more sub-sets by introducing saints. These semi-divine beings can represent aspects of the angels (gods) they work under, and they can have their own worship practices, temples and dedicated shrines, infinite numbers of new backstories for clerics that love that stuff, and so on. Saints can be specific to each domain, since they are derived from mortals from those domains, thereby achieving local character(pardon the pun). With saints, I've even let my clerical characters create their OWN saints to follow, so they can structure their own practices the way that's most fun for them to play. There's nothing more frustrating than when you have a clear vision about how you want to play a cleric, and then the DM decides to flip the rules around and say you can't do it (admittedly, the DM that rule swapped did it to please his girlfriend, but you get the point). This is not to say this approach can't create drama. When a denomination shifts far enough to stray into a new alignment, the resulting schism can be violent. Guess what? The same great drama that makes good storytelling makes great campaigns. You can add all sorts of fun role playing, where two churches to the same god come into conflict, or need to negotiate to achieve peace, or argue over the possession of a given artifact (or even the significance of the artifact...) [Answer] If five angels are running the place, each one must be overseeing a large and extensive number of things. Each domain should be fit into the angel whose portfolio matches it. That is, dismiss any rule that limits how many domains any divine being may preside over. If anyone questions why the angels grant such limited powers out of their vast portfolios, why it's as much as a mortal can handle, one domain's powers -- or the angels split up the powers so that mortals will need each other. (Or, of course, both.) [Answer] ## One God but many Dharmas One of the basic concepts of Dharma (in Hinduism) is that each person has a divinely appointed purpose in life, and that one's goodness is not measured by a single set of laws, but by how well one lives up to their purpose in life. So, a born warrior who chooses a life of pacifism is "bad" and is punished with bad Karma whereas a born doctor who chooses the same life may be "good" and be rewarded with good Karma. In this way, your angels could perhaps be appointed to rule over groups of people with similar Dharmas, but ultimately each person has a unique purpose written at birth; so, what is expected of them by the divine, and what gifts the divine deems appropriate in fulfilling that greater purpose is unique to the individual. So in terms of domains, each person (not god/angel) has domains assigned to him at character creation. Then each divine power is tied to those domains so that each cleric may have access to a slightly different set of powers while all worshiping the same god. Your God is trying to maintain a balanced and sustainable world, and he can't do that by enforcing universal laws; so, all of the conflicting natures of man are nurtured and encouraged by his singular greater plan. [Answer] # Divinity evolves Maybe you think you have a problem because in real life we sometimes think of evolution and godly things as mutually exclusive. But any good mythology has a long, winded history full of plot twists and plot holes. Think of the greek one: at some point Athens did not exist, so Ares was the sole god of war. Then one day Zeus has a headache and asks Hephestus to crack his head open with an axe (because he was too proud to ask Chiron for some aspirin), so Athens is born and because Zeus likes her, he giver her half of the domain over war. Overnight the clerics of war are divided into the orthodox arian church of war and the reformist athenian church of war! Then in recent greek mythology (circa 2,005 AD), due to a clerical error (drumroll) Kratos embarks on an odissey that makes him the new god of war, then the sole god of the olympus. That will throw a wrench in the way the greek organize their divine domains. This never happened on the bootleg roman version of that pantheon, so any Athens and Ares worhippers can still pray to Minerva and Mars, respectively. --- In your own world divine domains may change as gods kill themselves and new gods are created either through syncretism, mating or mortals ascending. Tie that to the campaign and you really have something epic in your hands. [Answer] ## Each God has multiple Aspects and Clerical Orders for different Domains Traditionally, gods had different aspects of their power. For instance Dianna was both the Moon and the Huntress; Athena was both a goddess of wisdom and of battle/tactics. You can readily adapt this to the different domains you want to make accessible to your players by having each god have different clerical orders focusing on separate domains/aspects. [Answer] You're only limiting yourself if you maintain the traditional one-to-one mapping between deities and cults. Instead, your five angels have overlapping realms of authority (like a Venn diagram, but in 5 dimensions). Each sect/cult worships two of the angels. This gives them access to a broader range of power, and that power is particularly strong where those two angels' realms of authority overlap. With your 5 angels, that gives you 10 different angel pairs to work with (or 20, if you differentiate one as the dominant/primary and the other as subordinate/secondary). As a simplified example, lets say you have a four-deity system based around the four classical elements (earth, water, wind, and fire). Practitioners of the healing arts could call upon the cleansing powers of water and fire. Warriors would summon the strength of earth and the swift, piercing wind. Nature-based magic (druids, etc) would embrace the fertile earth and the water that nourishes the life within it. Necromancers might beseech the earth to give up its dead so that they can imbue in them the fire of life's spark. The elements themselves have a range of meanings, and it's the conjunction of two of them that focuses that power into something a mortal can harness. [Answer] ## Different sects interpreting the same god differently Just look at the Abrahamic religions in the real world. While they all believe in the same God, there are not just major differences between the three largest religions (Christianity, Islam and Judaism), those religions also have lots and lots of different denominations and sects with very different believes regarding: * Which prophets and saints do actually speak on behalf of God. * Which scriptures are considered canonical word from God, which are the work of humans but still worth reading and which are heresy nobody should pay attention to. * How those scriptures they can agree on are to be interpreted and how their teaching should be applied in everyday life. * How different parts of these scriptures should be prioritized. When the worshipers of the one creator god in your world are similarly fractured into different faiths based on theological differences, then the clerics of those sects would also be very different. So when one player wants to play a character of a rather exotic cleric domain, then you just would have to come up with a new sect based on the believe that this particular aspect of the chief creator god is more important than all others. [Answer] When in doubt, fractals. Have a heavenly bureaucracy. The creator made 5 angels. Those angels in turn recruited spirits to aid them in their job. Each river that flows is managed by a river spirit. That river spirit in turn reports to the celestial sphere of water, when it gets around to filling out the paperwork. Keeping rivers on track and not meandering is a lot of work, and the celestial sphere of water has tides to manage, so it doesn't always get done in a timely (read: centuries) period. And once they have created a new riverbed, the paperwork to get them to move back is such a pain. There is 1 God. There are 5 Angels. There are more than 2 dozen Heavenly Spheres. Each has 100s or 1000s of Bureaucrats. And under them, there are millions of Spirits. A Cleric can serve a Sphere, a Bureaucrat, or even a World Spirit. Not just the God and the 5 Angels. ]
[Question] [ Imagine a field of plants that when walked through cuts human skin. Unlike a Stinging Nettle, the leaves would have to have razor-like edges, without the trichome hairs. The leaf edges should cause a finger to bleed if it were lightly dragged across the skin. The plant can be any height, shape, color, etc., but preferably about the size of a sword fern. The razor characteristic also needs to be consistent across seasons (it's not a rare event). How would these plants achieve their sharpness? Would metals absorb through the soil accumulate in the leaves? Could a symbiotic relationship help achieve organic razors? Bonus points if the plant is sharp enough to potentially kill or seriously injure someone while walking through a field. [Answer] Glass Some plants already sequester minerals in order to form blades in their surface: [grasses and phytoliths](https://en.wikipedia.org/wiki/Phytolith). Phytoliths are thought to be at least in part a defense mechanism against herbivory, abrading the mouthparts of insects and ungulates and releasing chemicals with their breakdown that further degrade vertebrate enamel. It's just a small step from that to go from micro-blades that merely wear down teeth to macro-blades along the edges of leaf margins that shred any animal that comes too close. We already have modern examples for a comparable phenomenon: [obsidian blades](https://en.wikipedia.org/wiki/Obsidian), which can be razor-sharp and slice into organic tissue very easily. To stop obsidian blades you almost need to be protected by metal or stone. And because these structures are being grown, not carved or manufactured, the plants can manipulate the formation of the blades on an almost nano-structural level to maintain maximum sharpness. [Answer] Try the Yucca > > When it comes to plants that have sharp edges, many gardeners may > immediately think of plants like succulents and cacti... however, many > other sharp leaved plants are available in the form of palms and > ornamental grasses... In many cases, plants that have sharp edges can > easily injure gardeners or their guests when planted in less than > ideal locations. Sharp plants, such as the yucca, have the potential > to seriously injure those who come into contact with its leaves. > > > Read more at Gardening Know How: Plants With Blades: Using Plants That > Have Sharp Edges In The Garden > <https://www.gardeningknowhow.com/ornamental/foliage/fogen/gardening-with-sharp-leaved-plants.htm> > <https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/growing-pampas-grass.htm> > > > ]
[Question] [ In my world superheroes are a branch of UNE (United Nations of Earth); think the EU for most of Earth. Many of them have super powers, but many do not. They have access to more advanced technology than the rest of the world, but they don't use guns in favour things like batons, swords, and knives. As they are part of the legal system, it makes sense to me to have this restrictions be a legal one. Is there a reasonable legal precedent that could make this feel more realistic. [Answer] ## Real World Precedent for Unarmed Law Enforcement In the United Kingdom most cops are not allowed to carry guns. Since common citizens are not legally allowed to carry most firearms in most situations, they are not considered a necessity for law enforcement to carry either. Guns are only carried by specialized tactical teams who are maintained for dealing with illegal gun threats. In your UNE, you could take this a step further by making firearms completely illegal for cops and citizens alike. Throughout history, anti-weapon laws have resulted in people going one of two ways: Either they are already criminals so have no qualms about bearing arms illegally, or they find the most lethal thing they can carry that is not illegal and learn to fight with that. So, your future tech criminals will have no problems 3-d printing their own firearms, whereas their law abiding counterparts will have no experience with or legal avenue with which to pursue the use of firearms; so, like the shaolin monks who learned to fight without swords, your superheros will be lawful expert combatants who've simply spent a lot of time learning to fight without a gun. As this relates to the trend you see in the UK, your UNE has made all firearms illegal across the board; so, your culture can no longer justify law enforcement carrying firearms despite the occasional career criminal outlyer. Since, the government still needs to have specialists who can suppress people who break this law, the government uses "Superheros". Bad guys may still sometimes have guns, but as long as you have special tactical units with personal shield generators, or full coverage class IV body armor, or invisibility suits you can still have law enforcement who can subdue those offenders without having to shoot them which tends to be the primary goal of law enforcement anyway. ## Fantasy World Precedent for Heros not Using Firearms I most fantasy settings, there are TONS of examples of heros who use non-firearm weapons in a world where guns exist. Generally this is justified in one of 3 ways: Option A: Guns are ineffective Since you have a world with people who have actual superpowers, many of them may be generally unaffected by firearms; so, your mundane heros will need to utilize technologies and tactics other than shooting to hold their own. If your opponent has super regeneration like Deadpool, then guns will pass right through him, but a sword can cut him in half allowing you to more effectively disable him. If you have a super with metallic skin like Colossus, then bullets may bounce off of him whereas a high voltage hand taser might do the trick. Certain technologies like [Holtzman Shields](https://dune.fandom.com/wiki/Shield) or sheer-activated polymers also have the potential to render guns ineffective compared to melee weapons. Option B: Guns are obsolete Since you have a future tech setting, there may be a plethora of NEW personal weapons that simply outperform traditional firearms for the purposes your hero has in mind. Power armor like that used by Ironman or 40k Space Marines allows one to simply walk up to a gunman and pull the gun out of his hand without putting himself at any risk of being harmed. Then you have things like electo-lasers, nanobot swarms, or Green Lantern's ring which could replace guns simply by being so much more versatile even without totally nullifying their effectiveness. Lastly there is the option of an offensive weapon that is just objectively more destructive than a gun like Thor's Hammer. Option C: Guns are unconscionable Most people who bare the title "superhero" have a general aversion to killing. Many heros like Batman, Daredevil, and Captain America would benefit greatly from carrying a gun, but choose not to for ethical reasons. And those that chose to use guns such as Punisher often wind up being seen as villains by these other superheros. While it is natural that some mundane superheros may WANT to use guns in your universe, they may choose not to because other in-universe superheroes are intolerant of killing. Since your superheros are bound by some code of law, it means that there are discrete rules to membership which could easily include a strict no-gun policy based on the moral code of your organization's founding members. This kind of "no killing" rule often meets some level of resistance, but is ultimately enforced by the leading members in many heroic groups such as the Legends of Tomorrow, X-men, etc. and with these rules, guns tend to become useless... with the very rare exception of perhaps John Diggle who uses guns just to wound while following Team Arrow's slightly less strict no-kill rule. [Answer] Superheroes mostly fight other superpowered individuals -- fights against normally powered people cause nasty PR, especially if death results. Non-powered superheroes are included; the general opinion is that if you're willing to put yourself up as a superhero, you're powerful enough that you shouldn't be beating up normals. (This is perhaps regulations rather than law as such.) For some reason, common superpowers result in bullets being ineffectual against the person. Given that all the weapons you list are hand weapons, perhaps it's a close personal forcefield that stops things that are not being actively propelled. Hence, a bullet, which is just flying from the explosion, stops, but a knife, being pushed by the hand, can penetrate. Once you train with hand weapons to the level necessary do this, you can't just switch to distance weapons without issues. Physicists are quite certain that this shouldn't work, but that's why they call them superpowers. [Answer] There's a saying in Tunnel in the Sky by Robert A. Heinlein that I'm fond of saying and I think works well here: "guns make you stupid". The logic behind this is that if you have a gun, you think you have power in the situation, which will cause you to become incautious. Heinlein mostly brings this up in the context of young adults going on an interstellar survival trip. The main character is specifically not given a gun because people with guns tend to think they're invincible, they don't bother trying to travel stealthily or pay attention to their environment because they feel like they can shoot anything that gives them trouble, and usually end up running headlong into the local megafauna rather than acting cautiously and stealthily and slipping around them. Being armed only with more basic weapons like a knife forces the protagonists to pay attention to their environment more, which helps in a lot of ways beyond just avoiding getting in fights with an angry stobor (like making you aware of danger before it happens). Now apply this to superheroes. You might have a non-powered superhero with a big weapon, maybe some kind of kryptonite gun that can take down even supers, but the problem is it causes you to become dependent on the weapon. You become a one-trick pony, the only thing you excel at is shooting the problem, and if you can't apply your go-to solution you're at a severe disadvantage. Even then, you're only human, so what happens if you're fighting someone who has better reflexes than you and can attack before you pull the trigger? If you don't have weapons it forces you to fight defensively, forces you to hone your observational skills and fight asymmetrically in order to avoid picking fights with foes that can dominate you physically. Ironically, by not getting in direct confrontations and adhering to the time old Harry Dresden wizard confrontation style of "blowing up your enemy from across the street, or across town if you can", you're greatly increasing your survival chances against a superhuman opponent. To quote Iron Man, "you have a big gun, you're not the big gun". [Answer] They are a POLICE force, and they are probably hunting other supers. That gun is going to be useful against the lowest of minions but above that you might as well bring your powered melee weapons and jetpack, or whatever your chosen tools of trade are. It gives you a better chance of actually beating these minions, it gives you a chance to ARREST them instead of murdering them with bullets and it cuts down on acceptable cas... collatoral damage. No bulletholes in cars, windows, furniture, walls and people! It also helps to counterbalance the superhero's. "Could the world just stay saved for 10 minutes?" Is probably not unheard off, and your superhero's might decide they can do a better job at keeping the world safe unless there's some normies fighting alongside them. Normies that could use their tools to check up on those superhero's and see if they dont become the very villains they fight. [Answer] # Bullets explode. Guns have an inconvenient aspect, which is that they rely on bullets/ammunition. The contract of a gun is, "this explosive remains inert until and unless I press this button, at which point the explosive is very carefully detonated in a very controlled environment to accomplish a particular purpose.” They only work as long as this contract is satisfied. Now, the bullet in the hole is a risk to whatever it happens to be pointed at; good gun etiquette says to never point a gun at anything you don’t want to destroy, even if you think you’re sure that it’s totally unloaded or uncocked or what-have-you. You just don’t take that risk. It’s hammered into you during training. We did the same thing when fencing: your prevot (fencing teacher; I don't know all the levels) says “who are you fencing next?” and you point your foil at Roberto and say “Roberto” and suddenly your prevot has grabbed the foil wide-eyed and said “don’t you DARE point a sword at anyone who is not suited up” and you’re like “but, the rubber tip on the top” and he is like “NO EXCUSES. My master was such-and-so and his master was so-and-so and his master was so-and-so and his master was grandmaster Aldo i@#$%ng Nadi, and one thing I can tell you for absolute certain is that none of these people ever had a student poke out another student’s eyes, and I do not intend to be the first. Got it? Twenty pushups, now.” (Not that this ever happened to me or anything, heh.) So a normal trained gun user will not be pointing guns at things that they do not want to destroy. But it still matters that this is how guns fundamentally work, you are carrying around a bunch of little explosives that are meant to accelerate death and you are assuming that the “rules” of the space are gonna be the same. Several superpowers will make this inconvenient, all for the same basic reason. If the bullets all go off inside the magazine, I mean, probably the magazine stays intact and the bullets do not do too much damage, but at the very least the gun jams. The bullet in the hole could unexpectedly fire which is, y’know, not bad because it wasn’t pointed at anything, but also not good. Especially if the gun is holstered it could nick the leg or worse, maybe. So you imagine someone has laser vision, that could certainly create a pocket of focused heat enough to replicate what the primer does. Lightning power might be able to target a spark just right inside the primer. Or pyrokinetics could do something similar. Sonic superpowers that head into ultrasound levels could replicate the sharp jab that the pin normally provides to the primer that starts the explosion. Telekinetics might be able to do the same thing, and they can do even worse: they can pull the trigger for you. Wrestling a sword away might be more force than they can muster, but pulling a trigger sounds more reasonable. For that matter, if you have it pointed at them, they might be able to enable the safety and thereby “disarm” you even if you are holding them at “point blank”, or perhaps it does not even need to be that overt, maybe they can stop the firing pin in its track or some similar action. Or, vice versa, you have your gun pointed at some supervillain, you are like “it’s over for you, Sparky, you’re going to jail” and then suddenly your trigger gets pulled without your consent and Sparky is dead and off in the corner of your eye you see some damn telekinetic running off down an alley. Now you have two problems: several people “saw you” shoot Sparky without reason, and the actual person who pulled the trigger on him has a huge lead on you so it looks like you’re running away from the scene of a crime. On the flip side, maybe you’re tracking someone with ice-based powers. What happens if they can freeze the gun so hard that the firing pin doesn't properly connect, or the primer is too cold to ignite or so? Could they fill the barrel with ice and misfire the thing that way? Do you really want to take that risk? Swords are quite reliable. Even if someone has reality-warping powers so that they are not sharp, they’re still a reliable big club of steel you can beat someone in the head with. Clubs, even more so. [Answer] ### Psychological trauma. Why wouldn't a non-powered superhero use guns to improve their martial capabilities? There are many possible reasons, such as them being masters of non-firearm martial arts and such, but there's also a very good reason for why they might not use them that hasn't been addressed by other answers, and it's the reason why perhaps the most famous non-powered superhero, Batman, doesn't use guns: psychological trauma. Batman doesn't use guns because a criminal used a gun to kill his parents, and that left him with the deep trauma that ultimately led to the anti-criminal vendetta that caused him to become the Batman in first place. As a result, he refused to use guns - if he uses a gun, it's a sign that he has become no better than the criminals he fights, and will shortly afterwards slide down the slippery slope of insanity and become a supervillain in his own right. [Answer] There are a multitude of legal precedents controlling and limiting the use of deadly force. I don't show them here because most are local laws governing police forces and I opted for an example at a national level. However, it would be easy to research laws governing deadly force (for example, search for "California laws limiting use of deadly force") and to use any of those to craft the idea that since your non-powered (or powered) superheros are already honking powerful by virtue of their skills and technology, that they are forbidden to use firearms. To simplify the precedent, limitations on deadly force exist because sometimes weaponry is too powerful for the situation and often cause more problems than they solve. Therefore, I give you [U.S. Code of Federal Regulations Title 10, Section 1047.7](https://www.law.cornell.edu/cfr/text/10/1047.7) > > § 1047.7 Use of deadly force.(a) Deadly force means that force which a reasonable person would consider likely to cause death or serious bodily harm. Its use may be justified only under conditions of extreme necessity, when all lesser means have failed or cannot reasonably be employed. A protective force officer is authorized to use deadly force only when one or more of the following circumstances exists: (1) Self-Defense. When deadly force reasonably appears to be necessary to protect a protective force officer who reasonably believes himself or herself to be in imminent danger of death or serious bodily harm. (2) Serious offenses against persons. When deadly force reasonably appears to be necessary to prevent the commission of a serious offense against a person(s) in circumstances presenting an imminent danger of death or serious bodily harm (e.g. sabotage of an occupied facility by explosives). (3) Nuclear weapons or nuclear explosive devices. When deadly force reasonably appears to be necessary to prevent the theft, sabotage, or unauthorized control of a nuclear weapon or nuclear explosive device. (4) Special nuclear material. When deadly force reasonably appears to be necessary to prevent the theft, sabotage, or unauthorized control of special nuclear material from an area of a fixed site or from a shipment where Category II or greater quantities are known or reasonably believed to be present. (5) Apprehension. When deadly force reasonably appears to be necessary to apprehend or prevent the escape of a person reasonably believed to: (i) have committed an offense of the nature specified in paragraphs (a)(1) through (a)(4)1 of this section; or (ii) be escaping by use of a weapon or explosive or who otherwise indicates that he or she poses a significant threat of death or serious bodily harm to the protective force officer or others unless apprehended without delay.1 These offenses are considered by the Department of Energy to pose a significant threat of death or serious bodily harm.(b) Additional Considerations Involving Firearms. If it becomes necessary to use a firearm, the following precautions shall be observed: (1) A warning, e.g. an order to halt, shall be given, if feasible, before a shot is fired. (2) Warning shots shall not be fired. > > > > > > > > > > > > > > > > > > > > > > > I should note that most deadly force laws explain when deadly force CAN be used, not when it CAN'T be used. The assumption is that there are fewer reasons why it CAN be used than CAN'T. [Answer] One explanation that I like is that the supers are more effective with the melee weapons that you describe than they would be with guns. Imagine, for instance, that they could deflect bullets with swords (sort of the way that Jedi deflect blaster rounds with lightsabers). Then the sword might be a better option for supers, though a much worse one for people who are not nearly fast enough to use a sword in the way I describe. For a more legality-oriented explanation: even though supers don't need guns, it still might be convenient to use them from time to time against regular people. Maybe it's easier to kill in mass, from a distance, etcetera, with guns than with a sword. The idea of some people using guns to kill others but being effectively impervious to them themselves is a concerning situation. I could see this being outlawed. Edit: Note that deflecting bullets is just one example of how to make guns less practical for/against supers. Another might be that they just move so fast that they're hard to track, that they are so thick-skinned or well armored that bullets don't do much, some combination of those ... there are options. ]
[Question] [ Nyarlathotep Is an ancient deity that has gone by many names; The black pharoah, the crawling chaos, etc. He seeks to bring himself into this world, but cannot due to an ancient barrier that prevents gods from crossing over. For his plan to work, Narly must be born as a child, who would serve as his avatar. This avatar would serve as a Dark Messiah, one who would bring ruin and chaos to the world. The person selected must be a virgin who is also infertile, unable to have children naturally. In ancient religious texts, virginity was highly prized as a symbol of purity. Mary was free of original sin, and the only candidate for the mother of Jesus. This is also a running theme in other works of folklore, with purity being linked to individuals worthy of note. Virginity meant being untainted or spoilt by the ways of man, which provides the resultant being with a certain specialness within a culture. However, Narly is a being of chaos and instability, associated with physical and mental corruption. Looking upon it's true form would bring about insanity and mutation. A being such as this would have little relation to concepts such as "purity" for its very essence causes chaos and disunity. It shouldn't matter if the individual was a saintly mother Teresa or Kim Kardashian like figure. How can I link this thrope to an Eldritch being in a way that makes "purity" a requirement for him to cross over? [Answer] # Purity is needed to trick the barrier > > an ancient barrier that prevents gods from crossing over > > > The barrier somehow detects intrusions from gods. Whatever the method for this is, it retaliates if foreign essence is detected in the world. So, a fast entry will be detected but a slow and steady one can bypass the barrier. Purity is needed because the more "pure" a person is, the more "of this world" they seem. A godly essence that taints somebody already corrupted will be detected immediately, but a god infesting a pure mortal can hide from the protection. However, purity is just the first step. A god is still overwhelmingly foreign for the realm and eventually would be detected by the barrier. Hence why the second part - a child being born as an avatar. Since the outer god doesn't immediately transfer all of its essence over in the world, it can take a foothold in the world and slowly increase its presence. For years, the god could act with diminished power in order to attune its essence to the world. I can forsee at least few different end goals here: * Eventually, the barrier will not think it a foreign power and would thus not retaliate. The god will be able to manifest into the world and take over, no other god will be able to interfere, as the barrier will still be in place. * Or perhaps having an avatar into the world will allow the god to more directly see to the dismantling or changing of the barrier. * The barrier might be a bit "dumb" and only detect what's the current "average normal" of the world within. If the god starts pouring more and more of its essence into the world, corrupting the other people in the process, eventually the god and its ways will become new "normal" and the barrier will start rejecting anything other than this god. Which will allow for a full manifestation and perhaps even the god merging its own world with the protected one. [Answer] # Virginity and sterility are required to circumvent the barrier. In [The Fionavar Tapestry](https://en.wikipedia.org/wiki/The_Fionavar_Tapestry), the Universe is a tapestry, and each being - as well as their actions - are threads in the tapestry. The evil one in that series, Rakoth Maugrim, gathers many of his powers from being outside the tapestry, to the extent that > > having a human son temporarily binds him to the tapestry, thereby making him killable. > > > A similar concept exists in [Life-Line](https://en.wikipedia.org/wiki/Life-Line), by Heinlein, where all humans are considered four-dimensional threads having a beginning and an end, whose length can be measured by technological means. Threads appear from their mother threads shortly after them crossing their fathers' threads (this also can be found in Scott Card's Alvin saga). The "barrier" could therefore be something akin to a [selvedge](https://en.wikipedia.org/wiki/Selvage) or finishing layer -- something preventing the tapestry from being unraveled, which does so by examining/interacting with the individual threads. It follows that someone who has "never known man", and is sterile to boot, would be somewhat like a thread that extends outside the tapestry: it has no twaining in its future, and it never crossed other threads in its past. It is a point where the tapestry is vulnerable, and a new "thread" can be spliced in; or anyway, where the thread itself is vulnerable. The action of Nyarlatothep would then be similar to a retwaining of that thread within the tapestry, which would be allowed. The thread, no longer technically sterile, would then give birth to the avatar from already inside the tapestry, and this too would be allowed. [Answer] Narly is a being of chaos and corruption. So it stands to reason that a vessel to contain his "seed" should be as close to incorruptible as possible. An "impure" person or fifty might have been tried in the past by the Cult of Narly. But these worshippers quickly succumbed to the immense corrupting influence of the tiny sliver of Nyarlathotep needed to spawn the required dark avatar, subsequently exploding into swarms of locusts with human faces. Only through repeated and gory trial and error did the cultists discover the traits that would allow one to carry the Son-Father of the Crawling Chaos to term. [Answer] Slag You are a blacksmith, would you rather work with pure metals, or something which has been contaminated with some random guy it met at a party during first year of college? It is known that when humans interact intimately with each other that their hearts meld temporarily and are never the same again. This can happen with a real person, or a theoretical one. A person who is infertile has had the idea of sharing their heart with a theoretical future baby stripped from them. So they don't even have that attachment. Once this pure material has been identified work can begin. She will discover herself pregnant, which will be odd to her considering her lack of a love life and the previous sterile diagnosis, but eventually that will leave her mind as she adapts to the reality that she will be a mother. Any joy she may have had about that fact is short lived. It is not a pleasant pregnancy. The doctor's have no explanation for her suffering, and most of them believe she's making it up. Along with the immaculate conception story she tells. They offer little to no support. What she does not know is that she is on the anvil of chaos. Her soul is being twisted. Shaped to the will of Narly. You see, his offspring does not have a soul, coming from non-human siring, it would be an empty vessel. The closest material to fill this vessel with is the soul of the mother bearing this living corpse. Like the mother spider eaten from the inside out by her spawn, this woman will endure having her self torn to pieces and reassembled into something akin to a puppet. As the months draw on she will appear less lifelike, less vibrant, more worn down and disconnected from the world around her. The birth will be painful, and there will be blood. By time the vessel is filled she has already lost any semblance of a social life. Her apartment, once colorful and filled with memories, now dark and filled with piled up bills and unwashed dishes. If anyone had been there to support her during this dark time they would see a borderline comatose woman twitching, convulsing and gurgling at the mouth with foaming bile. The crowing baby would seem to hardly be noticed by her. The person who finds her would say that they had some instinct to check on her. They would have no idea that the instinct came from an otherworldly source. They would be sad that they hadn't come soon enough to save her, but glad they could save the baby and make sure it went to a good home. Not the one it was born in, clearly by a drug addicted mother! The new parents are good people, a bit weird sure, worshiping some weird religion you'd never hear of, with a God with a funny name...Something starting with N maybe? Anyway, it's just good to know that baby will be taken care of. So weird it never cried, and it's eyes... [Answer] ## Hacking for Deities Footprint the target The barrier functions lot like a Software Firewall. Since Gods can project their power in many different forms, the barrier was designed to use SFW like heuristics to detect divine powers just like a SFW detects for computer viruses: By scanning them for qualities associated with known threats. The issue with SFWs is that legitimate programs often share characteristics with known threats meaning that in the course of maintaining functionality, the firewall must often be configured to whitelist suspicious activities which can be exploited by a hacker who knows what those whitelists are. By fuzzing the barrier with a wide plethora of powers he determines that the barrier is using the following parameters to keep him out: * Gods can not organically reproduce * They do not have physical bodies * They are made of spiritual energy * They are vastly powerful * They are bound to the virtues of their domain. For example: A god of war will never show mercy Find and Exploit a Vulnerability Because infertile women can not organically reproduce, the barrier looks at their other qualities, and whitelists their faulty reproductive systems. Basically saying yes, you have a divine aspect, but since you are clearly human, that will be ignored going forward, and therein lies the first vulnerability. Gods can not organically reproduce, but they can exploit this blind spot in the barrier's whitelist to non-organically conceive a child in a place that the barrier is already choosing to ignore. The birthing process itself is another blind spot. For the barrier to allow humans to have souls, it must let in and out small packets of spiritual energy. When a God goes to impregnate his vessel, his power works like a trojan virus. Because its function is to do the same thing that human souls do (create a life and inhabit a body), it will match all the heuristics of a human soul containing just the tiniest little obfuscated parcel of miracle power necessary to trigger parthenogenesis. Since he is just moving some DNA around in a single cell, this power is considered far to small to be divine intervention, and is instead ignored as a normal background anomaly. Now the Deity has cheated sexual reproduction, made himself a physical body, and limited the power he puts into this world enough to pass for human, but there is just one challenge left: he is still bound to the virtues of his domain. Once pregnant, the woman and child's souls will linked into one body. The will of the god and the vessel will contest for control, and the god needs to pick a human than can win that struggle. If a woman is already prone to giving into desires, then the god's soul will easily influence her to act according to the god's domain alone. This sudden change will be detected by the firewall. But if this woman continues to help others and be loyal to her friends out of the sheer willpower that is behind her virtue, then even if she starts murdering a few homeless people for fun, she will not appear bound to a domain, and thus both her and her child will still pass for human. Escalate Privileges and Patch Vulnerabilities When the deity is born, the barrier will need to decide if this thing matches the pattern of a human or a god. This baby was as far as the barrier is concerned born through the processes of sexual reproduction and has a fully human physical body with a soul inside of it; so ... looks a lot more human than anything else. Now the baby just needs to pass as human long enough that its non-human traits can be pass for normal anomalies, just as his mother's infertility did. Once grown up, the deity can use his human form to track down the source of the barrier from the inside and modify it by whitelisting himself; thus, fully allowing the god to push his power into the avatar. While he is at it, he may also decide to unwhitelist all infertile women casting them out into the abyss just to make good and sure that other gods don't come in the same way and try to ruin all his fun. [Answer] Purity is required as it is the only thing that could mitigate the chaos and corruption of the eldritch spawn for a long enough time to sustain the avatar's development in womb. A mere ordinary mortal would succumb to corruption and madness and destroy itself and/or avatar in process. [Answer] To be at somewhere close to full strength, maybe Nyarlathotep needs someone untouched by mortal means and someone unable to be distracted by mortal behaviors. Being a virgin would mean that the idea of mortal pleasure doesn't suit them [the vessel], and being unable to have children just means that the person is regarded as more suited to not be distracted by mortal pleasure. [Answer] Read purity as "having a feature of a single kind". A drop of olive oil in water makes the water non pure. Likewise a drop of water in the olive oil makes the olive oil non pure. It has nothing to do with the good or bad of the object. It's just being a foreign kind. ]
[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/142688/edit). Closed 4 years ago. [Improve this question](/posts/142688/edit) Humans in this world are born with the ability to communicate telepathically. The range and skill grows with age and practice, with adults being able to communicate between 5 - 7 ft. An individual can direct communication to a single person or group of people, and there is technology that can expand the range up to 25 ft. People can transmit clear thoughts, ideas, emotions and words through these communications. Cultures around the world use telepathy differently. In some, it is a form of intimacy between close friends or family. In others, it is used more casually and generally among public for fast communication. However, telepathy is more difficult to use than verbal forms of communication. It is generally reserved for short words or phrases, or simple ideas that don't require much complexity. It is rare for individuals to have an entire conversation telepathically. Why would this happen? [Answer] ## Thoughts are nebulous and personal, language is ordered and shared. Your brain doesn't produce thoughts one at a time in well-formed sequences with clear meanings. Many things are going on at the same time, all mixing together. Sensory input is processed all the time, triggering anything from memories and emotions to instincts, learned behaviors and thoughts. Before a conscious thought is fully formed, there might be dozens of half-formed ones, with all but one rejected. To add to this complexity, thoughts are shaped by the individual's life experience, memories, preferences, even the inclinations of their particular brain type. A visual thinker might have most thoughts as images or movies, that would be difficult to interpret for a pure verbal or mathematical thinker. All of this means that until a person decides to cast their thoughts into language, it is difficult to interpret what they are thinking, even when intentionally sending the message. The brain just can't help adding all kinds of context and related stuff, that's how neurons work. Even when the person is speaking out loud, a purely telepathic listener has to filter out all kinds of mental noise. That works for simple thoughts, but for longer conversations or complex ideas, it is much less error-prone and less tiring to let the speaker do all the filtering, ordering and converting to spoken language. Factors that make telepathic communication easier will be similar types of thinking, shared experiences and general familiarity with the person speaking. Family members might be able to communicate quite a lot telepathically, and the same might go for people that have worked together intensively for a long time. Strangers would find it very awkward. [Answer] ## It uses lots of energy Have using telepathy use quite a lot of energy, compared to the casual speaking with each other through normal means. Imagine the process of sending some data (e.g. words) as a very complex one, based on multiple subprocesses: * Step 1: Transform what you want to transmit into a fitting form. You could imagine it to be similar to the process of converting Text to its corresponding bytes and bits * Step 2: Transfer the data you just created. As you want the transport to cause as less loss as possible, you want to use short (radio) waves, which require more energy * Step 3: Convert the received data back to what they were before packaging and interpret them All in all the energy required to perform telepathy is quite big, and it multiplies when you try to talk this way not to only one, but rather a group of people. So it is way easier to just talk normally. --- Edit: An addition based on [@Nuclear Wangs](https://worldbuilding.stackexchange.com/questions/142688/how-would-telepathy-be-more-difficult-than-verbal-communication/142693?noredirect=1#comment447142_142693) comment To better visualize the concept of the en- and decoding and the fact, that you get better at it when you use it more / get older, think of it as translating into and from a foreign and at the start almost unknown language. The more you use it, the less effort it takes to encode your thoughts into this "language" and vice versa, so you can achieve the same with less energy being used / wasted. [Answer] It requires concentration Have you heard the phrases, "think before you speak" and "speak without thinking?" Those phrases exist because spoken language is trivial. Telepathic language requires substantial concentration. Curious consequence, it also means you're more easily distracted while trying to convey a message. You also need to concentrate to hear it. Otherwise it falls into the background noise of life (see the volume issue I present next). Coming or going, it requires far more concentration than speaking verbally. You can't shout, you can only direct The wonderful thing about spoken language is that you can pick familiar voices out of a crowd, which means a person shouting in a crowd is more easily heard by those who recognize their voice. You have the same kind of recognition with telepathy, but all telepathy occurs as the same "volume." This means you can't shout to be heard, you must focus your message much more accurately. Curious consequence, this means telepathy is much less useful than spoken language when it comes to searching a forest for a lost child. A way of manifesting this idea simplistically is that you can only communicate with someone you can directly see. No binoculars or other amplifying tools allowed. If you can't clearly see the target of your thoughts, they can't hear you. It's like learning another language: and everyone speaks their own language Most people think telepathy is like verbal communication: you can "hear someone speaking" without your ears. In reality, telepathy has everything to do with how you think, and the majority of our thoughts aren't words. They're emotions and reactions and associations and all kinds of things that frequently don't resolve into words. It can be thought of as an entirely different language with a few borrowed words from your native spoken language and a few more from whatever other languages you speak (like Pascal, C++, Fortran, and COBOL... wait 'til those thoughts show up!) The consequence is that until you learn how someone thinks, you're "hearing" a foreign language — the equivalent of spoken sound that has no meaning until you've learned the grammar and vocabulary. It's theoretically possible to "speak" in the thoughts of another person (a rare and very difficult skill, and very personal) but much more common to eventually learn how to understand what they "say." Curious consequence: this suggests telepathy can be readily used as a covert language. You're constantly having to protect yourself from the barrage One of the biggest problems with telepathy is that you're living constantly in a crowded room. You can't simply don some noise-cancelling earphones, you must train yourself to push aside the mental noise. This effort is, itself, distracting and substantially limits how much real communication can occur (similar to concentration, mentioned above). In effect, it's like conducting every conversation in a busy night club. You're constantly fighting to hear and be heard. Curious consequence: this makes telepaths prone to nasty headaches. Let's ramp things up a bit... Normal people are afraid... People are scared to death of both the advantages covert telepathic communication gives the gifted and the threat it represents against both society and the individual. So they invented jammers. Telepathy isn't magic. It's an honest-to-goodness scientific method of communication involving dark-matter sub-atomic particles named "Ondions" that vibrate in a mental field. Research suggests that Ondions are solely responsible for rational thought, for sapient life, for the soul, if you wish to express it that way. We do not think because we are, we think because Ondions are densely interwoven throughout neural tissue, giving the brain that magic oomph that allows for conscious thought. And what's really cool is that Ondions are everywhere, and thought is thereby transmitted in a manner similar to radio waves. Ondions "vibrate" (if this concept makes sense, it's not a physical vibration but a state-vibration. It's as entangled as any other headache involving sub-atomic particles), meaning thought creates tremors in the Ondion-quanta surrounding us and it weakens as it propagates from the center of thought by the inverse-cube — which was expected, that being a common aspect of nature. What trained people realized was, when within the interrupted quanta of a thought-generator, their own minds can sympathize with that tremor, allowing the two thought centers to synchronize momentarily. The brain interprets this as communication (but the possibilities are far more impressive than that). Which was all nice and shiny until a means of measuring the Ondion field and its vibrations was published in the IEEE Journal of Communications and Networks, including a description of the devices invented to measure the Ondion quanta. An organization calling itself "FrEMT" (pronounced "fr-eh-mt," for "Free Exercise of Mind and Thought") then turned the technology into a jamming tech that can block all telepathic communication. Then they learned that they could stop a person from thinking. When all the Ondions stop vibrating in the human brain, the human... stops. It's like the soul leaves the body and all that's left is the biological organism. It makes vegetables look smart. And then they discovered that by modulating the Ondionic vibrations they could artificially broadcast an idea... > > Reuters August 8, 2022 > > > Tragedy struck Philadelphia's 30th street station today when hundreds of people waiting for the arrival of celebrated telepathic composer André Quittet suddenly and without warning simultaneously stepped onto the tracks before the decelerating train. Witnesses were traumatized by what they consistently describe as the eerie and silent way the victims simply "stepped forward." Investigators have been unable to ascertain any motive behind the apparent mass suicide and no connection between any of the victims other than their interest in Quittet. > > > Quittet, an accredited master of the emerging art of érzékek, known as "telepathic music" by most people, has always been a strong advocate of … > > > [Answer] I'm gonna go the opposite direction from some of the answers: it's not commonly used because it's too darn easy (and instant) and once you've learned how to allow contact to a given person (or people) the connection is partially retained, meaning they can more easily get in touch with you this way next time, possibly with little warning or options. And the huge attendant issue is the effort involved to maintain both privacy (how do you keep *your* mind organised - you have "public" spaces and "private" spaces? No? Then if you could allow access, think about how insanely freeform and intrusive that would be) and appropriateness / germainity of what you share - you think people have trouble staying on topic verbally? What if they could dart off-topic instantly without meaning to, possibly not even being initially aware they were dragging their telepathic conversation partner along with them on their tangent thoughts? And as to appropriateness - whether it's a hormonal level reaction to someone's appearance, or a visceral reaction to their scent, or an unconscious rumble of general hormonal energy for a teenager / young adult, or even just errant thoughts that are off topic in a more professional or military or legal setting... or daydreaming in a crucial lecture in a super-important class... I think that casual use of this faculy would be simply fraught with risks. Moreover, you'd have to be a totally secure personality, with almost no significant quirks or hang-ups or neuroses to routinely allow others inside your thinking; and what if you were allowed into someone's mind for a discussion and in fact they were a raving paranoid with serious delusions - would you be able to differentiate enough to disengage? Would you be injured or scared or scarred? [Answer] There are telepathic "diseases" and/or "info-diseases". They're rare, but there are dangerous thoughts that can be transmitted which just stick in your head. Someone who is suicidal or murderous or filled with hate can inspire that in others. Emotions can spiral and be re-enforced by groups. Often that's a good thing (sex and intimacy). However a fully linked in group can "flash mob" where they're all thinking the same irrational thing at the same time. [Answer] Ah, Telepathy. Being able to communicate with others at a distance without any external physical activity. Why speak or communicate verbally/via gesture when you can share the concept itself that you want to share without any confusion? Unfortunately, it's not that simple. Tobias mentioned a need to convert your message to a form that can be transferred, followed by decoding of the message. However, there is much more nuance and difficulty than just this. First, Telepathy will be slow and exhausting, and will require extensive training to utilize effectively. Let's say that you want to send the concept of a specific breed of cat to someone else. You, as the sender, must first conjure up the idea of what that breed of cat is. Memories will almost certainly not suffice for the details of what it looks like. Even trying to visualize the cat will take time and concentration. Once the cat concept has been prepared, it must be sent. The recipient must be located, a link established, and the content packaged into a proper form and sent. The recipient must then decode the message - and there will probably need to be some kind of standard so that they know how exactly to do so. Drawing further inspiration from Network Protocol, there's also the issue of security and ensuring that data isn't compromised by some other person/third party. Though I doubt Man in the Middle attacks would be too much of a problem with Telepathy due to latency issues and the content of messages, it would still be necessary to encrypt and decrypt messages using some form of standard protocol, again adding more complexity. Once this is done, an acknowledgement or response must be sent. Who knows just how much time it takes to have a single exchange? In this timeframe, a few words (e.g. 'calico cat') when spoken would have sufficed. Of course, the words 'calico cat' could have been sent via Telepathy. But this brings up a second issue - the expressiveness of Telepathy. When humans communicate, facial expression, body language and gestures, intonation, etc. all convey meaning. Think of a phone call - how much information is lost when communicating by phone? And think of communicating by text on the internet? Everything but the words themselves is lost. With Telepathy, emotions may be sent, and words and concepts may be sent, but sending all of the other information causes the message to bloat in complexity, going back to the first problem of Telepathy being slow, exhausting, and requiring training to use effectively. It's just easier to communicate via speaking. And as a final point, if someone is being contacted by multiple people at the same time, it will almost definitely result in significant mental stress. Will people have to block messages? Is it even possible to do so? Society would be a much more stressful place, especially if people who are blocked resort to shouting or yelling. [Answer] Why would people use spoken language over telepathy, given a native capacity for telepathy which can be polished and improved over time? 1. Different people organize their thoughts in different ways - and arguably in different internal "languages" I am a sometimes visual thinker. That is, some of my reasoning is entirely without words, but the specific images, quasi-images, and system-connections I employ would be of no significance to anyone else. I have some reason to believe that other people may have more sophisticated emotional modelling than I do, and significantly worse systems-thinking. It seems probable to me that if I were to drop certain of my thoughts directly into someone else's head, those thoughts would seem like gibberish. In order communicate, I have to first translate such an idea into English (often with a lot of added explanation of context). Telepathy would likely not bridge the natural context gap between individuals. 2. Telepathy may share more than was intended (or less, with misleading implications) As alluded to in the first part of the answer, there may be a context gap when telepathically communicating sophisticated thoughts or feelings. That undertone of contempt for some relative or acquaintance? Are you also communicating the years of mistreatment you received... Or will you come off seeming unreasonable yourself? Maybe you even are unreasonable, in ways you can hide from yourself, but which would be obvious to someone getting a taste of the thought without all of your own rationalizations. 3. Potential backflow of ideas might build up a social stigma around careless "wide-open" connections If your telepathy is not perfectly one-way, it may be considered bad manners to open up an unguarded connection, in the same way touching (or putting your hands under the clothes of!) someone else is taboo EXCEPT in very specific situations. People are very careful, across most cultures, to not be too intimate; it's not your business to help yourself to other people's feelings or thoughts. This would be particularly the case if you can feel other people "snooping" in your head. Telepathy would naturally be a very intimate connection, with the implication that it would be subject to the same taboos we have attached to other forms of intimacy. Also, 4. Many thoughts are clearer if you can articulate them to yourself in words - and thus many people would be more able to communicate their thoughts better in words than in impressions anyway [Answer] # To noisy or requires focus "People can transmit clear thoughts, ideas, emotions and words through these communications." The hard part of this question is that people can "transmit CLEAR ...". If I can assume the information relayed is clear and not confusing (I can send each word I would normally speak) I see multiple options but 2 that stand out. 1) Just because I can speak clearly and relay information with no misunderstanding doesn't mean I can do this in any situation. What happens if no one is able to drown out thoughts or stop broadcasting them. You either are open to everyone's thoughts or you temporarily stop listening to everyone (like closing your eyes. You either see everything or nothing). The brain hasn't developed an ability to focus in on one person trying to communicate. In society where you are surrounded by people, this would cause you to rely on visual and verbal communication where your brain can help you isolate and focus a source (think of talking in a loud bar). The second is strain. I might be able to do it but it requires great mental focus to use. Think of playing an instrument and dancing. Not to say it is impossible (clearly not) it just requires more training and focus than most people are willing to put into it. Without focusing on it people tuning (listening) into you would just get white noise. It has meaning but the brain is not complex enough (has yet to evolve) to decipher/understand it. With this I could have broken conversations with people over telepathy but without cause I would simply choose to communicate as we do currently. [Answer] Maybe because it's new technology. When texting came along, old people would still make calls for a long time after young people had caught on and had whole relationships over text messages. In your world telepathy might be a very accessible technology that anyone can use at any time but if most of your characters are over the age of 25 they will probably use other communication methods that they're already familiar with. They will only resort to telepathy when it suits the situation much more than anything else. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). Closed 5 years ago. [Improve this question](/posts/126158/edit) Aliens, robots, Biblical creatures disguised as a cute girl transfers into [protagonist] school is a cliche. But, how do I really do it? Assume, Local skin tone, Accent, Mid-class and other average student physical characteristics. The being has sufficient common sense and mental health to not look out of the ordinary. But, has no, ID card, birth certificate , basically in the eyes of the government doesn't exist. Like just pop out of nowhere. Like a bastard born child kept quiet or something. How to solve this assuming mind-control and all manner of magic is out of the question. Actually does not have to be a super-natural in the first place. [Answer] What age is she? Where I live undocumented children will have no problem getting into elementary school as it is considered a human right. She will have to be able to convince the school that she is a "proper" undocumented alien though, as opposed to an abductee or something. Any sign of abuse or neglect on her will get the authorities involved very quickly. Being fluent in a foreign language might help her keep up the appearance. Higher education is a problem. She is gonna need a social security number and some means of identification. These can be forged however, and as long as she avoids scrutiny she will be fine, nobody will investigate. As long as all bills are payed and she plays "average student" well there will be little problem. As another answer already mentioned though, she will have to have some people to act like her parents/guardians from time to time, for as long as she is supposed to be a minor. They do not need documents, but will have to act convincingly. [Answer] If the school is big enough to have a complex bureaucratic systems the only thing required is to someone from inside (or even a hacker) to add the new students to the system. The teachers may not care about the student life outside school, so nobody will audit or double check the archives to see from where that person came from or ask if they were really suppose to be there. That works even better in a big city or in a community without strong ties where parents of students don't get into each others business. [Answer] Identity theft 1) Find a cute girl of the required age who is about to transfer into said school. 2) Occupy her body or kill her and wear her skin. 3) Brainwash the parents if necessary. Chances are the changes in her personality can just be explained by puberty. [Answer] The question really becomes what forms of verification does the school require. Which essentially boils down to how strict does the person that "admits" students want to be. In some locations proof of being an adult that lives in district is enough to get ones "child" enrolled. So if the student had another entity, essentially a person of parental/guardian age that could show proof of residency it would be little issue to get someone in to school. As the district becomes larger or more sought after as a place to attend shool this likely become more difficult. Getting someone into a school with a legal age helper would be much easier than a school age person being admitted on their own though. Imagine a 16 year old walking up to a school secretary asking to get enrolled. They are far more likely to be referred to a foster organization then be allowed to attend classes without some adult to vouch for them. [Answer] Greetings prinipal of prestigious private school. I am an eccentric billionaire and I'd like to enroll my daughter. She doesn't have any documentation because the documentation butler was actually an actor hired by my nemesis and I had to fire him. Hopefully you can arrange all of that for me. How many sacks with a dollar bill sign on them should I leave with you? [Answer] Have an ally with valid ID adopt the supposed child from a country with bad records, to then get valid ID for the country with the school in. Celebrities like Madonna do so frequently! [Answer] A couple of ways that do not involve hurting/killing anyone 1) Simply bloody yourself up and be found in an ally by the police. Pretend you do not remember who you are and the government will likely make a perfectly legal entry in the system for you. 2) "Immigrate" from a country with bad/no records, to a friendly country (like Canada). Again, the government will make a perfectly legal identity for you. 3) Grease the palms of the morgue staff to "forget" to file a death certificate for a Jane Doe (even better if her name is common). Assume this person's identity. As a magical/alien creature, you can likely trade fairy dust or ray guns easily. 4) Simply show up and act like you belong there. Several [con artist](https://en.wikipedia.org/wiki/Catch_Me_If_You_Can) have spent years playing the bureaucracy ]
[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 5 years ago. [Improve this question](/posts/124858/edit) Why aren't cities developed in circular area? Just as the grid system of city planning circular system can also be opted. What will be the pros and cons of circular cities? (Assume the terrain to be plane , new land and just you and your ideas) [Answer] True curves are relatively difficult to construct, especially over large distances. Obviously you can't take a huge compass and draw a city-sized circle on the ground, so you have to make a lot of measurements and everything needs to be very precise or it falls out of shape. On the other hand, straight lines are comparatively easy to work with. However, radial cities don't necessarily have to be circular: they could take the shape of a polygon with many sides, with streets radiating out from the center, and avenues parallel to each side of the outer perimeter. This sort of city planning was popular during the Early Modern period, in conjunction with a style of fortification called "star forts". For instance, here's a map of Palmanova, Italy ca. 1597: [![Palmanova, Italy, 1597 (from Wikimedia)](https://i.stack.imgur.com/Frg3O.jpg)](https://i.stack.imgur.com/Frg3O.jpg) (Image courtesy of Friend Wikipedia) As you can see, the city is laid out in concentric rings, although those rings are nonagons (nine-sided polygons) rather than perfect circles. Polygonal ring streets are easier to lay out and easier to fit buildings into, while in turn being easier to fit into the structure of the fortress wall. (It should be noted that many cities with such walls had perfectly ordinary rectangular street grids, or irregular streets. They just cut them off wherever they needed to build walls.) [Answer] > > Why aren't cities developed in circular area? > > > ## Sometimes they are [![Palmanova, Italy, founded in the 16th century](https://upload.wikimedia.org/wikipedia/commons/0/06/Cinta_muraria_di_Palmanova.jpg)](https://en.wikipedia.org/wiki/Palmanova) [Palmanova](https://en.wikipedia.org/wiki/Palmanova), a town and comune in northeastern Italy; founded in 1593. (Photograph from Wikimedia; CC0 license.) [![Place Charles-de-Gaulle, formerly Place de l'Etoile (Star Plaza), Paris](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ac/Place_Charles-de-Gaulle_-_OSM_2016.svg/616px-Place_Charles-de-Gaulle_-_OSM_2016.svg.png)](https://en.wikipedia.org/wiki/Place_Charles_de_Gaulle) [Place Charles-de-Gaulle](https://en.wikipedia.org/wiki/Place_Charles_de_Gaulle), formerly Place de l'Étoile (Star Plaza), Paris, France; built in the 19th century during the Second Empire of Napoleon III as part of Haussmann's renovation of Paris. Map by user Paris 16, from Wikimedia; licensed CC BY-SA 4.0. [![Baghdad, the Round City](https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Baghdad_150_to_300_AH.png/749px-Baghdad_150_to_300_AH.png)](https://en.wikipedia.org/wiki/Round_city_of_Baghdad) [The Round City of Baghdad](https://en.wikipedia.org/wiki/Round_city_of_Baghdad), built by the Abbasid Caliph al-Mansur in AD 762–767. Map by William Muir (1819-1905), from Wikimedia; public domain. [![Plan of the Round City of Baghdad](https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Umar_Farrukh%27s_the_round_city.png/710px-Umar_Farrukh%27s_the_round_city.png)](https://commons.wikimedia.org/wiki/File:Umar_Farrukh%27s_the_round_city.png) Plan of the Round City of Baghdad, from Tareekh Al-Islam Al-Musawwar (Ilustrated history of Islam) by Umar Farrukh, Lebanon, 1964. Public domain. [![Old city of Shanghai](https://upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Map_of_the_Old_City_of_Shanghai.jpg/785px-Map_of_the_Old_City_of_Shanghai.jpg)](https://en.wikipedia.org/wiki/Old_City_(Shanghai)) Map of the [Old City of Shanghai](https://en.wikipedia.org/wiki/Old_City_(Shanghai)), by user World Imaging. Licensed under CC BY-SA 3.0; from Wikimedia. [![Augustus B. Woodward's design plan of Detroit](https://upload.wikimedia.org/wikipedia/commons/thumb/4/47/Old_map_1807_plan.jpg/505px-Old_map_1807_plan.jpg)](https://en.wikipedia.org/wiki/Roads_and_freeways_in_metropolitan_Detroit) Augustus B. Woodward's design plan of Detroit, after the fire of 1805. "[Detroit's monumental avenues and traffic circles](https://en.wikipedia.org/wiki/Roads_and_freeways_in_metropolitan_Detroit) fan out in a baroque styled radial fashion from Grand Circus Park." (Wikipedia) Map from Dickens, Asbury & Forney, John W., eds. (1832) "Plan of Detroit" (Map), in American State Papers. Vol. 6: Public Lands. Image available on Wikimedia. Public domain. [Answer] > > Why aren't cities developed in circular area? > > > Because it doesn't make sense to. There are no perfect circles in nature and any irregular shape will be better filled with a grid system. It's also much easier to expand in any direction. Circular is constrained to expanding in all directions. Also in engineering it is generally easier to engineer a straight line than a curve, importantly it is also easier to calculate areas, stresses etc, this holds true for most of our engineering. Hence many things we make that looked curved are actually just a curved facade built on mostly straight lines. Worth mentioning is transport, straight lines are preferable for many reasons. Imagine the difference in difficulty calculating a 1/4 acre section with curves rather than straight lines. And the total difference in shape of the quarter acre as you progressed from inner to outer. The most important reason to use straight lines is it's much CHEAPER. [Answer] A thing I would add to the other answers: The vast majority of cities grow organically. Meaning they expand, when needed, in any direction possible. [As Kilisi pointed out in his answer](https://worldbuilding.stackexchange.com/a/124859/44086), it is significantly simpler to build somewhat rectangular than circular. You need to put a lot more effort and knowledge into it. And since most cities were not designed from inception they grew somewhat randomly. People were just like "I am gonna build a house next to the other house". And that several thousand times over decades and centuries. Why would you expect that to form a circular shape? ### Current day city planning The reason it is mostly based on a grid as it can simply be scaled into any direction. It is a lot easier to grow. A circle would always have to expand as a circle. That is extremely unflexible. Especially if you also want to keep it somewhat symmetrical in there. Just imagine the same circular city passing through the ages. In the very beginning there might not even have been plumbing. And now it would need to have that, electricity and internet. Unless someone would supervise every single construction work that was to be done over the centuries your city will never stay somewhat symmetrically circular. ### Possible advantages of circular cities They are nice to look at structure-wise. Not really an objective bonus, though. Another thing they bring is defense. Since a circle has a minimal outline you need less wall per area than a rectangular city would need. Unfortunately, that is completely pointless in modern times and would more likely be a defense catastrophy, since the introduction of long range artillery, bombers, etc.. Nobody could escape in a walled city, especially not if the wall is minimized and has a few entrance/exit points as possible. [Answer] There are some cities that are developed in a circular area. In developed countries, a lot of city layouts follow the [Concentric Zone Model](https://en.m.wikipedia.org/wiki/Concentric_zone_model). In this model, the central business district, which is the city's center and provides business and public services, is circular. Outer rings surround the city and provide consumer services and housing. While the city itself may follow a square layout of buildings and streets, the general shape of these rings are round. So to answer your question, yes, a lot of cities are circular in shape, although that doesn't mean they have a circular layout. [Answer] Circular The circle is the shape with the largest area for a given length of circumference. Thus, if you want to erect city walls, a circular shape, or an approximate circular shape gives you the most city for your wall. Extending a circular city is much harder, i.e. more expensive, than expaning an irregular-shaped city, since you need to build a full, bigger circle. Rectangular A rectangular is self-similar when divided. If you divide your city in quarters, then each quarter of your rectangular city will be a rectangle. This is most evident in the way the Romans built their legionary camps. Such [Castra](https://en.wikipedia.org/wiki/Castra) are the seed of many a European city. Real world The strict grid-like cities are an invention of modern times. If you take a look at remaining medieval city centers, e.g. here is the inner district of [Regensburg](https://www.openstreetmap.org/#map=17/49.01847/12.09350), which has largely retained its medieval layout, you will see the layout is pretty chaotic, compared to modern cities. Real world cities will in most cases assume some irregular shape, due to * geographical features * political contrains * opportunity [Answer] Some circle-ish cities do exist - take Beijing for example: [![enter image description here](https://i.stack.imgur.com/NkNxW.jpg)](https://i.stack.imgur.com/NkNxW.jpg) It has Ring Roads, to enable easier travel around the city. However it is still based off a square grid pattern, for the reasons people mentioned earlier. * Building's tend to be square, so they fit most efficiently in a grid pattern * Straight lines are just easier to build and plan * Better for travelling - No need to constantly correct because the road is drifting imperceptibly to the left But as you can see Beijing did expand in a somewhat-circular fashion. Some of this can be attributed to strict central planning for the government. [Answer] The original EPCOT Plan by Walt Disney (not the amusement park, the fully functional city) was a flower design where the city's buisness and commercial areas were in a central circle and the residential areas were smaller connected circles like petals on a flower... at various points, public transportation in the form of a train of some sort would circle the main hub and make connections to transport going into the center city and out to various residential areas. Vehicular trans power in the central area was to be entirely through tunnels leaving the open air portions of the city center were entirely pedestrian with the public transport being elevate train lines. [Answer] After reading all the answers above .... I recognize that most of them are saying that circular township would be expensive than grid or irregular township But I would remind you all that when the first civilization should have been set up it would also be too expensive. The point is that if earlier people started building circular township we (HUMANS) have bring in technology to it and we would have made it cheaper . If you or anyone of you understand my point please upvote it and comment for more. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Closed 5 years ago. * You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). * This question does not appear to be about worldbuilding, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). 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/120517/edit) So, I'm working on a video game wherein there's a lot of supernatural stuff "legitimately" going on around the player, but the player character is also schizophrenic, and realizes as much. So what's really happening, and how much the player is actually contributing to solving the problems presented in the plot will always be questionable. The player's schizophrenia manifests as voices and hallucinations. Some characters in the story will be revealed as fake, and others won't. The game takes place in a near-future war-torn world, riddled with dangerous unexploded ordinances, automatic turrets, maybe even some robots (maybe), and such. At one part in the story, the player will be traveling cross-country with 3 or more comrades who do not realize that the player has this problem. The player character can't tell them, because then the player would be a liability on the group and would be cast out. One of the comrades is a hallucination, and the player has to find out which one. For this part of the plot, I plan to put pressure on the player to find out which friend is a hallucination, using situations where the player has to depend on his friends. For example: the player and two friends are separated from the rest of the group; they find themselves needing to cross a mine field, and the two friends take separate paths through the field, both urging the player to follow them for safety (I might not use that idea; it's just an example). I've got ideas for how to give the player clues as to which friend is a hallucination after the player already knows that one of them is, but I don't know how to initially make it clear that one of them is definitely fake without telling which one. What do you guys think? How can I reveal to the player that one of the NPCs in his party is a hallucination without revealing which one? ETA: I'd like it if your answers didn't take into consideration any mechanical gameplay limitations necessarily. Feel free to also consider the question as if I told you I was writing a book and wanted to reveal something to the main character. I'll use what parts of your answers I can use in order to work out my final product. Thanks! [Answer] Have someone refer to the number of people in the party. E.g If you have a party made up of Alice, Bob and Charlie, but Bob is hallucinating that there's also Debbie, everyone always refers to "the three of us". Bonus points is that it's subtle enough that it might escape notice the first time, as the player might not count themselves. [Answer] You could have supplies (food, water, ammo) decreasing as they are used by the real humans, leaving potentially a very subtle clue to the player who may not notice the rate of consumption is apparently wrong. A clever way to make it more visible might be if they find a pizza with eight slices -- which should be evenly divided by four people, but somehow they end up with 2 slices after everyone gets two. You could increase the obviousness of the clues in stages, eventually getting to the point where someone refers to "the three of you", or charges them for three tickets on the train, or something. [Answer] I've run across this, or something like this, about twice where it was done well. The first is Hellblade, which while I never played, [Mr. Wendle On Games](https://www.youtube.com/watch?v=i0cU2M4vQ4Y) did a great exploration into it. Among some other things the game did that tied it all together. In terms of hallucinations and how the game achieves that, the other answers here have it pretty well covered: whispered audio, visuals that only exist for the character (and the player), and the complete redaction of standard "4th wall" aspects, like a health bar. The health bar isn't reimagined as some feature on the character's model, no, it's gone. Everything about the game works to immerse you in being the main character, along with all of her insecurities and hallucinations. The game never tells you to press keys or move your mouse or anything like that. Instead you get an audio track of whispered voices telling you to "look around" and if you don't, those same voices get angry asking, "why won't she look around? Just look around!" The second time was the anime [School Live!](http://www.crunchyroll.com/school-live), I highly recommend watching the entire first episode before reading the details below. Try and spot the hallucination--and who's doing the hallucinating--before the reveal. p1. about episode 1 > > One of the characters is so far in denial about the fact that she and her friends are trapped in their school due to a zombie apocalypse the entire first episode never shows anything but her delusions until the final seconds. Additionally, one of the other characters is a hallucination, showing up in every scene in nearly every episode. The other characters do interact with the hallucination, or appear to, making it much more subtle for the viewer (and thus work well). > > > p2. about the rest of the series > > Even after the first episode it's hard to tell that the teacher, Megumi, is a hallucination, even knowing that the Yuki lives in her own little world. Megumi died a horrible death before the first episode and there are occasional interactions with her from characters other than Yuki, though usually when Yuki gets upset that the others didn't say good morning or thank her. Its played so straight it ends up looking like they don't respect Megumi and just ignore her, when in reality she doesn't exist at all: Megumi looks sad and starts crying when she doesn't get the response she wants, but never overtly tries to get the other girls' attention, just moping in the background, because she's so quiet and not much of an authority figure. It's so well built into the who Megumi is that it feels natural. > > > It was done so well that I was not convinced that there was the one hallucination for several episodes. I could tell that something was "off" but I hadn't been able to put my finger on it. [Answer] ## A known hallucination tells the player about the other hallucination, but doesn't specify who it is. Not subtle, but sometimes you need a hammer. ## The friends go ahead, leaving individual but anonymous traces. The player follows two sets of footprints to where three friends are standing. The friends themselves are standing on rock so the footprints end before they can identify their owners. ## Three people fit in a space for two. After a brief separation, the player comes across the three friends standing by the wreck of a two-seater car. [Answer] Each of the three companions has a distinct personality. Two of the comrades interact with each other, and with the player, but never with the third. This entails conversations, sharing, helping etc. The player eventually is given clues as in other answers (for example a reference to the number in their party, a failure of person in the line of fire to be hurt) that the third companion is a hallucination. Actually the other two are also hallucinations. This becomes evident later - for example the character crosses soft ground and on turning, only one set of tracks is evident. The character is alone. Realizing that the others are hallucinations does not dispel them. The hallucinations themselves, once told, may or may not be ok with their nature. They continue on with the character. Their insights and interactions may still be helpful. ]
[Question] [ Assuming a civilization has the capacity to build space vessels designed to travel from one solar system to another, what is the technological difference between traveling at 50% light speed and traveling at 100% light speed (or near)? And then, what kind of technological leap is required to go beyond light speed? The idea is not to have "hyperjumps" but that there is a constant speed most ships can go. So traveling 4 light years takes 4 years at light speed. Takes 8 years at 50% light speed. you get the idea. I am trying to decide how technologically advanced humans in my space-travel-based universe are. Would it make sense to say "We are only advanced enough to go x% of light speed"? Or is Light-speed the real barrier here? What are the limiting factors to going very fast (subluminal)? Assuming light speed is the real barrier, would anything really stop anyone going near light speed given enough fuel and distance to reach that speed? [Answer] Assuming known physics, there's no way to go 100% of the speed of light ($c$), but (in principle) you can get as close to it as you want. So let's compare $0.5c$ (50% the speed of light) with $0.95c$ (95% the speed of light). There are a couple of big differences between travelling at these speeds. The first is the amount of energy needed to reach them. In space it doesn't take energy to keep moving at speed - if you don't do anything you just keep coasting at whatever speed you're moving - but you need to use energy to speed up and slow down. Let's calculate how much energy it takes to move at the speeds mentioned above. The kinetic energy of an object moving at relativistic speeds is $$E\_k = m\gamma c^2 - mc^2 = \frac{mc^2}{\sqrt{1 - v^2/c^2}} - mc^2$$ (from [Wikipedia](https://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies)), where $m$ is the mass of the object and $v$ is its velocity. Let's use units where $c=1$ and let's assume $m=1$ as well for simplicity. Now an object travelling at $0.5c$ has a kinetic energy of about $0.15$, while an object at $0.95c$ has an energy of about $2.2$. This measures the amount of energy you need to get up to speed, assuming the mass of your spaceship doesn't change. You can see that getting up to $0.95c$ takes 14 times more energy than getting to $0.5c$. However, it's likely to be much worse than that in reality. For most methods of propulsion you will need to take more fuel with you to get to a higher speed, and that means more mass, which means more energy. These feedbacks combine in an explosive way, so that travelling just a bit faster usually requires an exponentially larger amount of fuel. This is called the [tyranny of the rocket equation](https://what-if.xkcd.com/38/), and is generally not your friend. Don't forget that it takes energy to slow down too, since you definitely don't want to be travelling near the speed of light when you reach your destination. If you want to go even closer to $c$ you will have to spend even more energy. Travelling at $0.99c$ requires about $6.1$ energy units, and $0.999c$ requires $21$. As you get closer to $c$ you'll need more and more energy for smaller and smaller gains. Accelerating to $c$ itself would require an infinite amount of energy, which is why you can't do it. The other big difference between $0.5c$ and $0.95c$ is collisions with space dust and other particles. Space is almost empty, but if you run into even a tiny piece of dust grain of sand at $0.5c$ it will hit like a nuclear bomb tonne of TNT.1 A larger object, with mass around 1kg, would be comparable to a nuclear bomb. At $0.95c$ it will hit with 14 times the energy, due once again to the higher kinetic energy. Such collisions are inevitable on a journey between stars, and so most serious concepts for interstellar travel have a huge bulky shield in front of them, to protect against this. The closer you get to c the more protection you need from collisions, which adds more mass, which again requires exponentially more fuel due to the rocket equation. In conclusion, everything you say in your question is basically right. Nothing stops you from going as fast as you want given enough time, fuel and distance, but these practical considerations mean there's a huge difference in the amount of technology and cost between travelling between stars $0.5c$ and $0.95c$. 1My initial guess was way off, my apologies. [Wolfram\|alpha](http://www.wolframalpha.com/input/?i=(c%5E2%2F(sqrt(1-0.95%5E2))-c%5E2)(1%20kg)) is a useful tool for doing these kinds of calculations, and I should have run it through that in the first place. Although the energies involved are smaller than I expected, colliding with dust grains at relativistic speeds will release a cascade of subatomic particles, and the radiation from this is probably more dangerous than the initial release of energy. I am not an expert on this stuff, though. [Answer] What percent of the speed of light you go is not really a function of how "advanced" you are. So long as you have reaction mass for thrust (or whatever your particular method of acceleration is), you can get arbitrarily close to the speed of light. Obviously, you need some minimum tech level to be able to fly in space and navigate over long-distances at all. The limit on how fast you go is therefore based primarily on your particular engine design, any external motive systems, and how much reaction mass you carry, all of which is relative to the overall mass of the ship you're using. But these elements of technology don't map to the practical speed of a ship. So you can't look at a ship that travels 75% of the speed of light and judge anything about the tech level of the people who made it based solely on that. Maybe they had a stationary magnetic accelerator in their launch system and are relying on high-impulse propulsion to slow them down. That's not particularly higher of technology that someone who uses low-impulse propulsion over a long duration to achieve the same speed. [Answer] [The Wikipedia page on time dilation has a great chart](https://en.wikipedia.org/wiki/Time_dilation#Formulation). When you add more energy with any thruster (assuming abundant reaction mass or bonkers Isp) as you get closer to light speed less energy is going into your relative velocity and more is bleeding over into time dilation effects. From the chart it looks like you start seeing some serious losses in Δv above 0.3c. Above 0.9c most of the energy from continued thrusting is going toward time dilation and not toward getting anywhere any faster - and then you'll have to decelerate which equates to a whole lot of wasted fuel. So above 0.8-0.9c there's no advantage to trying to go any faster. Any limit below that is going to strictly be limited by the amount of fuel you can carry (or find, if you are going the ramscoop direction where you use a magnetic inlet to capture and fuse interstellar hydrogen), the efficiency of your engines, and the relationship between acceleration and distance between start and end points. For example, you could have very high efficiency but very low thrust engines for interstellar travel, so you may need several lightyears to get up to 0.8c. In this case you're average speed would be lower for "short" hops like from Sol to Alpha Centari, and approach the 0.8c cruising speed as you make very long journeys. As a plot device, any sort of race in the 0.8-0.99c range where it's worth it to burn insane amounts of resources to gain a few days or hours on the competition could be interesting. Faster than light is the big jump because with our current physics, no one knows how to do it. With any known propulsion method, we would just lose acceleration and speed to the time dilation effect. Any FTL method is going to have to abandon the Science and lean on the Fiction. [Answer] I assume when you refer to speed, you mean relative to earth or some other planet, as all speed is relative. There is no huge difference between getting to different sub-light speeds, more thrust is simply required to go faster. However, do keep in mind that going near light speed, the effects of time dilation get very noticeable. A journey of four light years might take a few years for the people on your ship, but centuries for everyone else on the planet from which they launched. Nothing can actually go faster than light, as this would mean going at a theoretically infinite speed and cause you to go back in time. You might however want to look into the [Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive), a theoretical warp drive which creates a bubble of spacetime, contracting space in front of it and expanding it behind. This means that the ship technically isn't moving at all, and would allow the it to travel at any speed with no time dilation. There are of course many problems with it, such as energy requirements and radiation, but it could work for your story. Basically, the biggest technological difference is whether or not your civilization has discovered a way to go faster than light. [Answer] You bet there's a difference* * In [1804](https://en.wikipedia.org/wiki/Land_speed_record_for_rail_vehicles) the first steam rail locomotive could scream along at 5 mph. * Steam improved by 1830 when the Stephenson Rocket hit an earth shattering 30 mph. * In 1848 steam — or should I say, rail — had hit 60 mph. It took nearly 100 years to get to 100 mph. All this time, the technology to move the mail was changing and improving. Steam reached its peak in 1938 with 126 mph. * Then the technology changed and diesel was introduced. In 1936 diesel hit 127 mph. By 1980 it was up to 152 mph. * Then the technology changed again, and today we have mag-lev trains that top out at 375 mph. My point is, there is a HUGE technological difference between 0.5c and 1.0c. I'm ignoring completely today's understanding of physics. World history has proven over and over that "today's" understanding imposes few actual limits. Said limits tend to be overcome by "tomorrow's" understanding. Once humanity can build a ship that can reach 0.5c it's altogether likely that we'll have figured out the physics behind getting to 1.0c. Anyone who tells you "...can't be done, because..." is forgetting that people 100 years ago were saying the same thing about many of the technologies we enjoy today. However, when you ask, "...what is the technological difference...," that's a question no one here can answer. You're asking us to postulate the operation of technology that doesn't exist in our wildest dreams, and then extrapolate from that ignorance whether or not light speed represents an insurmountable barrier. Remember! Scientists actually thought the sound barrier was insurmountable until we figured out how to do it and [Chuck Yeager actually did it](https://www.washingtonpost.com/archive/1997/10/08/how-chuck-yeager-broke-the-myth-of-a-sound-barrier/43a1af7c-adbc-463d-8e96-2a9fc9bcb909/?utm_term=.82271d13b506). Today, we can't see how to overcome the light-speed barrier ... but we've walked across a barrier once before. I wouldn't be at all surprised that we do it again. It just takes a better understanding of the problem than we have today. Regrettably, it's the habit of science-oriented people to believe that what we understand today is all there is and all there will ever be. History has proven them wrong time and time again... but they believe it anyway. So, you'll be inventing the "technology" that your story needs to accomodate space travel, but to answer your title question, yes! It makes reasonable sense to say, "that species can only reach 0.25c." as a reference to their general technology level. Indeed, this kind of reference has already been used in Star Trek where some species are only capable of "warp 4" while others are capable of "warp 7" and it's hands-off non-warp-capable species because [Clarkian Magic](https://en.wikipedia.org/wiki/Clarke%27s_three_laws) would make you look like gods and that's considered poor sportsmanship. [Answer] > > Assuming a civilization has the capacity to build space vessels designed to travel from one solar system to another, what is the technological difference between traveling at 50% light speed and traveling at 100% light speed (or near)? > > > I'd say, pretty significant. To achieve a speed of X, you need to gain a kinetic energy of mX2 and that energy, whatever your propulsion system, ultimately comes from fuel. But since you need to have the fuel with you, that's more mass that you need to have with you when you start. In the end, it's a matter of energy density. Then, relativistic speeds offer two important challenges that your technology must overcome: * anything in space - dust, grit, stray protons, gas molecules, junk - in your trajectory becomes a projectile hitting at relativistic speeds. You need to be able to either locate such obstacles far enough, and maybe manoeuver fast enough, to avoid them, or survive the smaller impacts. * at relativistic speeds, your ship-clock time slows down. This means that you have even less time to detect obstacles, less time to react, less time to manoeuver. At 99% c, you send out a pulse at the speed of light towards a half-kilo pebble floating one million kilometers in front of you. The pulse takes 3 seconds to reach the pebble; in those three seconds you've covered about 895,000 km and are at 105,000 km from the pebble. The pulse goes back, and you detect it when you're at less than 10,000 km from the pebble. To move a space of s = 50 meters off from your route, hold the relativistic slow-down, you have around t = 0.03 seconds. Given that $s = \frac{1}{2}at^2$, this gives $a=\frac{2s}{t^2}$ = nine thousand gravities. So: you either have technology to survive accelerations two orders of magnitude above lethal, and detection technology capable of locating position and speed of a pebble one million kilometers away; or a detection range proportionately higher; or the capability to survive impact, and a half-kilo pebble at .99c has the same effect of a multimegaton-range fusion bomb. > > And then, what kind of technological leap is required to go beyond light speed? > > > The impossible kind, for all that we know. It's a sort of Chinese Corridor race: every technological leap you do will halve the distance separating you from light speed. So you go from 50%c to 75%, to 87.5%, 93.75%... but you will never reach c (the Engineer's response in the joke is "Yeah, mate, but I only need to get close enough). > > So traveling 4 light years takes 4 years at light speed. > > > Welllll... actually, 4 light years at light speed takes no time at all, if you're aboard the ship. Time contraction again. That might be an advantage. Of course, reaching near enough the speed of light takes time. > > Would it make sense to say "We are only advanced enough to go x% of light speed"? > > > Yes, it makes a lot of sense. > > would anything really stop anyone going near light speed given enough fuel and distance to reach that speed? > > > At a certain point, exotic effects become observable and begin kicking in. The most relevant is probably the Doppler-Zatsepin effect, whereby you observe the ubiquitous microwave background blue-shifted towards higher energetic levels. In other words, wherever you look you see a gamma-ray laser firing at you point-blank with energy enough to photodisintegrate the ship. This phenomenon limits the distance traveled by a fast-enough particle to what is called the [GZK limit](https://en.wikipedia.org/wiki/Greisen%E2%80%93Zatsepin%E2%80%93Kuzmin_limit). Accelerating further will expose you to a different but equally nasty effect: the [temperature of the vacuum](https://en.wikipedia.org/wiki/Unruh_effect) will appear to increase. So, relativistic travel is hot, but wearing :-) [Answer] There is one crucial term in your question that perhaps needs exploring. You do not ask in terms of 'anything' but in terms of 'anyone'. That is, can a HUMAN travel that fast? We really have absolutely no data on how any biological process would function at that speed, let alone a human. The trick is, we have to ACCELERATE to that speed. We know that space flight has repercussions on the human body, and on biology. We DON'T know if these effects are cumulative. As an analogy, consider a change in temperature. Frogs will freeze to death at a slow drop in temperature, without sensing it. Humans, on the other hand, show physiological reactions in order to maintain a specific body temperature. Could, somehow, constant acceleration to a faster and faster speed have a biological effect? We don't know. No human has yet accelerated to such a speed. We know almost certainly that biology depends upon quantum effects. Quantum tunneling, for instance, in electrolyte transport through the cell, and in photosynthesis. Will the quantum effects be somehow altered? So what happens to human biology, or biology in general, if the organism is subjected to a constant acceleration that results in a speed approaching that of a massless particle? Are humans adapted to operate optimally in an environment of an acceleration and velocity range typical of earth, and would we have extreme difficulty in adapting to any other environment? So, in answer to your question, yes it is possible that humans (not things) might have limitations on going that fast, and these limitations would have to be addressed by technology beyond that which we currently have. > > EDIT > > > I found the reference that, in part, addresses this. [Speed kills: Highly relativistic spaceflight would be fatal for passengers and instruments](http://www.scirp.org/journal/PaperInformation.aspx?paperID=23913) > > Unfortunately, as spaceship velocities approach the speed of light, > interstellar hydrogen H, although only present at a density of > approximately 1.8 atoms/cm3, turns into intense radiation that would > quickly kill passengers and destroy electronic instrumentation. In > addition, the energy loss of ionizing radiation passing through the > ship’s hull represents an increasing heat load that necessitates large > expenditures of energy to cool the ship. > > > [Answer] > > Assuming light speed is the real barrier, would anything really stop anyone going near light speed given enough fuel and distance to reach that speed? > > > I'm pretty sure the answer to the spirit of your question is very simply "no". 1. Say you are going any speed, whatsoever. Any speed. To go faster, you simply attach a rocket at the back and light a match. Once again, no matter what speed you are going, to go faster you just fire a rocket. There is utterly no difference whatsoever, at all, in the fundamentals. 2. Regarding travel at light speed, like a photon (or faster than light speed). This is simply utterly impossible, based on our current deepest understanding of mathematics. Regarding point 1, of course - obviously - you might need staggeringly big rockets and other astounding engineering difficulties. (You may well need fusion! or anti-matter! engines to make huge amounts of electricity - whatever. You would surely need some sort of astounding laser technology to blast out of the way any micro-particles in front of you - etc etc.) Once again, thanks Einstein - any speed at all, whatsoever, is identical to no speed at all. There is absolutely no difference between speed and no speed. (Note that indeed our planet (indeed, our galactic group) is whipping along at an astounding speed; when we take off to the moon we just "add speed" - the "original" (staggering) speed of the planet means absolutely nothing.) # Speed and no-speed are the same. In contrast - point 2 - traveling at light speed (or higher) is utterly and totally different, requiring utterly new base mathematical concepts, totally and completely unknown to us. ]
[Question] [ Technology: Comparable to early XXIst century, except self-driving vehicles are already available. On a tidally locked planet most of the models that I can found (ex. <http://www.meteo.mcgill.ca/~tmerlis/coupled_tidally_locked.html>) tend to predict permanent hurricane-like weather near the substellar point. To make everything more tricky, on the planet that I am planning for my story one of key sea routes should go near this point, thus ships would have to endure hurricane each time. 1. How would such a container ship look like in comparison to ships that we know from our planet? Would there be any significant shape change except making everything much more sturdy? Will there be fewer layers of containers above desk? Anything more? 2. In case of transporting any crew, any idea how to provide them with safety and comfort? Except of course putting them in to well... a padded room? 3. Or maybe the whole idea is not worthy and if one exists, a longer but safer route is the way to go? [Answer] The conditions of hurricanes are very harsh and easily become a trouble for any surface going ship. They are even that dangerous to ships, that only the most specialized ships go through them at will - and these ships are made to withstand harsh environments by design. Most of the ships that can cope these weather are modern service vessels for offshore wind energy parks or icebreakers and both are designed and tested with ice, freak waves and extreme wind conditions in mind. However, these ships are comparable short and couldn't carry more than a few to some dozen containers - which is why these ships are able to endure the extreme waves. Longer ships have a tendency to break under their own weight when some parts loose water contact. [![a recent & modern Service Operation Vessel used by Siemens in the North Sea](https://i.stack.imgur.com/ul89s.jpg)](https://i.stack.imgur.com/ul89s.jpg) But while a hurricane or any other Beauford 10+ wind does disturb the upper 5 to 10 meters of the ocean, the sea below is relatively calm. So our first step will be to get our ship under the ocean. The result will pretty much look like a Typhoon Class nuclear submarine, just instead of missiles, it carries some containers. Or in a picture: [![Russian Tyophoon Class Submarine - just replace missiles with cargo](https://i.stack.imgur.com/o4mRb.jpg)](https://i.stack.imgur.com/o4mRb.jpg) [Answer] Going through a hurricane is no one's idea of a good time. There's many things that can go wrong with a ship in rough conditions: * The ship is simply flooded by waves, and sinks * The ship is flipped to far off to a side, and floods * Cargo becomes loose, bangs around the interior of the ship, and either punches a hole in the side, or causes the ship to capsize * The back/structure of the ship breaks under the pounding of the waves, and due to cargo placement, etc. > > Note: structural damage is a thing. Modern torpedoes don't necessarily impact the ship anymore. They explode under the ship, create a cavity, and the ship simply breaks in half. > > > Anyway, let's say that you really need your ships to go through these hurricanes. You're looking at a design which is partially submersible, much like a modern lifeboat, which is fully enclosed. Of course, this will mean that it would have to be both huge, as well as have a smaller overall capacity than a ship which is not constrained in this manner. It will basically look like a floating zeppelin. You'll want to make a point of lashing the cargo down very, very well, and you're good to go. These things will be pounded by the waves, even go under the surface in severe conditions, but as long as the dome isn't compromised, the ship should float back up to the surface. You could take it a step further still, and basically design them as giant submarines that only travel at very shallow depth (say, less than 50 meters under the surface) - enough to avoid the weather, but not have to survive crazy hull pressure. They would probably have to be nuclear powered. [Answer] Spheres. Spheres are the strongest 3D shape if you take the average strength of all points on their surface. There shape would make them impervious to a lot of the threats a hurricane presents. Picture a stubby submarine that floats on the surface. * They would be less prone to structural damage as they are much more self-supporting than the traditional long shape of a ship. * It doesn't matter how big the waves are, you can't flood a sealed sphere * You also can't capsize a sphere. And the orientation of the "hull sphere" may not even matter if there's an inner rotating drum One problem here is the size, you wouldn't want massive spheres as the structural and hydrodynamic costs would become unruly. So how do you achieve the capacity needed? How about chains of spheres. I still need to think about how you could connect the spheres in a way that would withstand the hurricane... Another thing I haven't yet figured out is how the spheres would propel themselves through the water. I am imagining one of two situations though: 1. The spheres are physically connected together and the "tug sphere" at the front has the sole role of driving the chain of spheres through the water. This sphere's contents could be entirely dedicated to whichever drive mechanism works 2. The spheres act as a swarm, not physically connected and each with their own means of propulsion. They could use pretty basic swarm tactics to remain in their group, but not so close as to collide given the hurricane conditions. This concept has a nice futuristic feel to it In both cases, crew are not essential. Our world is already on the brink of unmanned global shipping. If crew were required however, you could contain them within the sphere. Inside the spheres I would imagine having and inner-sphere that rotated independently from the outer-sphere, thus protecting the cargo and crew from the outside tempest. Living conditions would be very similar to a submarine I guess, so no need for a padded room! [Answer] 1) You could have a 'segmented' cargo ship. You have the main surface ship suitable for harsh weather as mentioned in Trish's answer. Short and tough. With all living quarters, engines, and possibly the most valuable cargo containers. Then instead of having a traditional long cargo ship that will break apart due to shifting cargo, or due to its own weight when it loses contact with the water, you have segmented cargo hulls. Like a train, pulling cars behind it but have a ship towing floating hull barges. I wouldn't just have one tow line but several dozen. It would still be fairly rigid but allowing the length if the ship to always stay in contact with the surface water. These floating barges would all be fully double hulled like traditional modern hulls. They would be able to maintain their own orientation ie won't tip sideways or flip over but stay 'right side' up. Not round or spherical but square or rectangular. I would limit the number of segments, to one or two, possibly three, as otherwise you get too much sideways movement during storm activity. You can also have it, that this segmentation only occurs during storm activity. All other times the ship is pulled back together and travels in the traditional streamlined manner. You may have to redesign the ship propeller system. Make the trust come from the forward section rather than 'rearwheel' drive. 2) I assume storm activity wouldn't be continuous? Instead of a padded room you can have safety rigging or webbing near all system critical systems. Crew can lash themselves into the webbing that would provide a limited 'suspension' unit. They would be protected from most of the random ship movements and still be capable of work in a particular restricted area. (this isn't like being tied in place, but rather hanging in a suspended webbing similar to bungy ropes, but not that stretchy. Or you could have a combination of different rigging systems depending on what sort of work is necessary) You may find that your storm crews will be larger than modern day earth crews, to compensate for this restricted movement during storms. Instead of one or two engineers running all over the place ensuring the engine is working, you have three or four (or more depending on engine requirements) located at all necessary critical areas in suspension webbing. Crew sleeping quarters will probably be designed to allowing sleeping in a lashing/webbing. Recreational night visits may be very interesting. Of course, there will be scenarios that require people to move around as needed, especially in emergencies. Ensure all machinery, furniture corners and wall edges are rounded. Ensure that everything is tied down and prevented from flying around. Essentially childproof the ship. ]
[Question] [ I have a world (around 3000-3500ad) where human race is spread across various planetary systems - so interstellar travel it's possible. The interstellar travel is possible via a [Bussard Ramjet](https://en.wikipedia.org/wiki/Bussard_ramjet) which uses the [CNO Cycle](https://en.wikipedia.org/wiki/CNO_cycle) to propel itself. Each planetary system has a couple of planets/moons colonized and interplanetary travel is quite accessible. Now, in my story, the idea is that human race colonized Mars and the Moon (all this before hitting 2500ad) and after that developed interstellar travel and went to Gliese 667 and colonized Gliese 667Cc. But after thinking about it I thought "Why wouldn't the human race pospone interstellar colonization and instead terraform other planets/moons from the solar system (ie Venus, Mercury, Europa), and not go for interstellar colonization until all solar systems planets/moons are terraformed and habitable?" And I couldn't really find a reason as to why. So basically my questions are, what would be more likely to happen first? The colonization of the entire (as much as possible) solar system or interstellar colonization? Or maybe both? Which one would be easier? Why would human kind go for one or the another? One of the many reasons in my story is that human kind needs more space - immortality has been discovered so earth is lacking space. [Answer] As I know very little about your world and your terraforming and travel methods here are some general ideas. 1) Terraforming is expensive — Terraforming in the solar system costs more than travelling to already habitable planets. Maybe interstellar travel costs next-to-nothing or terraforming requires a rare/expensive element. 2) Terraforming takes time — The planet needs space now. We can't afford the 1000 year wait for Venus to become habitable. The only way to gain space in time is to hop off to another planet in another system. 3) Some planets can't terraform — The moon and Mars are both rocky planets at a reasonable distance from the sun. Mercury and Venus are just to hot to work on. The equipment would melt. We can't terraform the gas giants and Pluto's too small to make it worth-our-while. 4) It's not allowed — Many areas are protected under conservation laws meaning no building can be done on them. Maybe something similar applies to our solar system. If one of the above is true then I would suggest that humanity would go for interstellar colonisation first potentially with some terraforming going on slowly in the background. I would think humans would go for interplanetary ahead of terraforming even if they were roughly equally costly as humans often prefer to build something new rather than adapt/recycle something they already have. [Answer] ## What is given What is given? Humans have a practical problem, they need living space. But for how many? How fast population grow? As for the first question, some believe that for Earth 1 billion ($10^{9}$) people are ok, and what is above is excess, there are a bunch of other believers. But solving the problem is to solve the problem, so export 0.1% of the population isn't solving it, 50% - yes maybe it's a significant change. As for today, 50% is 3 billion people. This way - how many? - is probably billion(s) of people. How fast the population grows, as for 2012 average grow was 1.1% per year. There where higher numbers in the past, 1.8%, 2.2% , [World population](https://en.wikipedia.org/wiki/World_population). There are different beliefs about the growth rate, how it will change in the future, and why it is happening. But let us go with 1.2%. I will skip immortality as insignificant for that problem, as the problem will exist without immortality, and as a factor which consequences I can not predict. I think with immortality grow rate may be at 0% easy (because mortality is one of the driving factors for having children). As note: grow rate isn't something fixed, as we may see, [boiling frog](https://en.wikipedia.org/wiki/Boiling_frog) works and people are happy to accept even negative growth under some circumstances, with immortals it will be 0% grow so using fixed value is more for illustrating purposes. * population, 11 billion, growth rate 1.2% per year, desired(optimal) Earth population 10 billion, and let say 10 billion per each terraformed planet. ## Interstellar There are some factors that are important and are pro- early interstellar colonization. One star system is limited in resources, like energy, heavy elements, and because of the exponential nature of population grow at some point grow will outcome ability to send people (sustain one human needs power roughly 10kW (24.7.365), sending it needs more even with almost free Bussard jet engine.) And at that point civilization is almost stuck, until it loses some weight or finds some other solutions. Let's say in each star system we will find, on average, 10 bodies, which we can terraform, this way average population per star system will be 100 billion people. So if we send at early stage 1 billion people in each star system, and left with 1 billion people in the solar system. For the next 400 years problem is solved, as with 1.2% growth per year, it needs 200 to 10x multiply in population, and 400 years to 100x multiply. $\small 1.012^{200}=10.87$ But is that really a solution, or better to say longer to lasts solution, because expansion isn't the solution at exponential growth, because the exponent is damn fast, it beats everything we might suggest as a solution, at least for now. Starting at 11 billion population, and have sent 1 billion to each of 10 stars nearby, after 400 years we will end with the need to send people to 10000 stars, 1 billion people for each star as we did it before - to buy another 400 years. (return to the state with 1 billion per system) When does this strategy stop working for the solar system? When it has to send people farther than 400 light-year - they send 1 billion and they will arrive as 100 billion. So a star system has to send let say 100kk, just to give them some time after arrival to do something before they will have the need to send another pack of people themselves. * they multiply at travel, because otherwise, it makes no sense, they could stay at home, and not multiply there. They travel because they wish to multiply. (and for simplicity of the picture) Good thing is, with that strict policy of 100 billion per star system they will have plenty of energy to use it to solve that population problem, they are not stuck in the system, they have plenty of resources to just fly in another galaxy if they wish, or time and resources to find another solution. One of the problems is that each of them will begin to solve that problem at a different time and they will have a different starting point and different optimal strategies. But how fast solar system will have the need to send at 400+ ly? [Stellar density](https://en.wikipedia.org/wiki/Stellar_density) * The true stellar density near the Sun is estimated as 0.004 stars per cubic light-year So 400 ly distance is 1'000'000 stars in that volume, given 100 billion per each star, starting population 10 billion - this volume with radius 400 ly will be inhabited in 1400 years. There can be better strategies in sending which propagates this time a bit. For example, sending at the beginning right to the maximum distance (let's say 400 ly), and they will send also to the maximum distance. Sending at a greater speed to have time dilation effects as an example, this way we might send 1 billion people and they will arrive as 1 billion people. Hibernation through relativistic effects. ## Local system, not interstellar, not terraforming There are some difficulties in sending people interstellar, and most important is: what will they find there? Green worlds or mostly rocks which they have to convert to habitable worlds. Most likely a bunch of planets not suitable for terraforming. But let see what is our system's maximum capability by supporting human life. [Sun](http://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html) Power is 3.828×1026 W And if we assume 100kW of it per person, and that is enough for food and lifestyle we(some of us) enjoy now it's enough for 3.828×1021 population. For how long it might last with 1.2% growth per year, for 4166 years. ## Problems overview, Critique planetary, and terraforming approaches. Many of those, who are not lazy to think about non-FTL future (and those who consider interstellar travel in generation ships - all of them) forget about a simple fact - to make a generation ship or just a ship which traves a long time, the ship needs to be habitable in the full sense of that meaning. Every detail we enjoy or consider as the reason to terraform a planet - have to be on that ship. Period. It has to be this way, not only for the duration of travel but in the duration of terraforming a planet. Terraforming is Art and Exam which may take 1000's years to accomplish. Obviously, I'm not sure about 1000's years, and I may imagine something which may terraform planets in let's say 50 years or maybe less - with perfect knowledge about what it doing, perfect knowledge about properties internal structure of the planet, perfect prediction of important moments of how the biosphere will affect that planet, and how that will affect the biosphere. Not sure if that perfect knowledge is possible at all, because of the nature of processes involved - waggly, unstable, changeable - on a fundamental level. The nice thing about a biological system is that it will adapt and find its own equilibrium in most cases - but will we be happy about that equilibrium or will we complain like here [Jellyfish Invading Japan](https://www.youtube.com/watch?v=6HP0_7_RRwg). just a jellyfish, which can be eaten, not something we can't eat, and taste is fine, but no no, we do not like that. That is kinda sarcasm, but a tiny difference will make significant a significant impact and create a system that we might not enjoy. All discussion I have seen about terraforming, in recent times in connection to Mars stuff - they forget a simple Fact - In a place where we can live, in the place can live everything that lives on Earth at the moment. On a planet-scale, to undo some errors -it may be impossible without the destruction of the planet. I mean microbiological live mostly, especially one which lives deep in the soil, and which is important for the cycle of life and death. But with other nonmicrobial life, it is also not so simple, at least at our current level of technologies, which sure is subject of change in the future, when we research and will gain more knowledge, but still, it might be not an easy task to control them. Terraforming task is way much bigger than just blasting a few nuclear bombs on poles to release ... I consider [disassemble of planets](https://worldbuilding.stackexchange.com/a/45273/20315) an ordinary task, it needs just force, tool, energy - and ok, done. Terraforming, in a way we might enjoy the result, and accept as equivalent or better than Earth variant is opposite of that, it is almost no force, but pure Knowledge. So talks about difficulties getting the atmosphere, water - it is just a minuscule part of terraforming, the easiest part of it. As an example, growing a forest - it requires 100's of years, just for the first generation and as result, it will be not a forest but a park - it needs more than that until it will begin to be a forest, especially in case if we do not prepare the soil for it to be like in a forest, thus it might take thousands of years just for the thing to grow and create look and feel of a forest. I even do not talk about 1000 years old trees and forests out of them. Problems like that may be solved, but we are even not close atm for being able to do that. ## Why not go to other star systems as places to live The problem with planets in other star systems is one problem, I would say the least important one. There is another more important problem, in that non-FTL future - the speed of information transmission. FTL is possible or not possible - not known at the moment. And to know it and probably build it, if it is possible - we need to do a lot of researches, lots of information have to be classified, data exchanges, a lot of work have to be done. Placing parts of our civilization in places with 400-year ping - does not help in that. Yes, there are partial solutions for that information exchange problem - as an example nodes can be more independent in terms of information, each works at its slice of problems, or in some direction, or randomly picking problems from possible problems, but it does not make everything better it makes it just less worse or same in computing power sense, but anyway, important changes will distribute themselves slower and overall solving different problems like as an example FTL problem it will be slower. There are also other social identification problems, with groups - less likely to agree to work on common problems, and sense of what is the common problem will drift - work can be done, but that long ping and consequence do not make solving faster and easier. And a planet-oriented civilization(which expands and uses only planets) has 1400 years of its expansion, or less if there are not enough plants for them to use. If civilization relies on a just solar system and space habitat's and energy/matter delivery they have 4000+ years for their expansion with the same population growth rate. After that, both have to change their habits and try to maintain the 0-growth rate. Space habitat systems might be established in other star systems too, but the speed of information exchange is a problem here as well. ## How it might be done better. * do not terraform planets just for a living - it's a very inefficient use of available materials, losing scientific information about the universe, which may be important for our future survival. * Learn how to live in space, build space habitats - way much easier than terraforming planets, and needed anyway for long trips. * learn how to use resources in the solar system on a large scale * send tech seeds to other nearby systems, to research these star systems * grow seed to be able to supply our system with energy and heavy materials we might need or are used here - the process of energy/material transfer can be combined, and be a very efficient one. * test that supply system on nearby systems, and begin to extend the system with 0.9c define collection points - make energy material transfer grid-system. * establish an interstellar transportation system for those who would like to take nice pictures on vacation trips, send those people across the galaxy at 0.999999c. This way it is possible to grow influence sphere almost with the speed of light, store energy for future use from many stars, do large scale projects, make efficient travel system(with almost 0 energy loss and at desired time dilation) Do different researches with high energy demands, or if building FTL needs a lot of energy, then this way we might have needed energy. We all will have common goals and fast information exchange in a more compact group - and it might help to solve problems. Storing the energy of stars is very simple, just by disassembling those stars as an example. Such a process needs a lot of energy and there are lots of useful stuff besides H and He. Assembly them back to get energy back (not very efficient, but better than just losing lots of energy as it is now). The most efficient and profitable way is to store energy in traveling people and ships(as kinetic energy) by building a global travel network, getting that energy back at the arrival point, or extracting it as needed in any system. More energy we will conserve at early stages more freedom-mobility we will have in the future. Each second of sun energy, conserved, will allow 3 more people to travel in the future with 10000-times dilation. Each year - 100kk. At the moment galaxy is just wasting the energy which we might use. ## Exponential grow Exponential growth will catch up with any strategy, even the FTL strategy. Not a big deal trough - as may be seen on any creature living on Earth - humans included. For how long it will last with 1.2% growth and expanding the sphere of influence at 0.9c speed, which collects all resources - energy, heavy materials - and send's them back to Earth(solar system). Without energy conservation for about 4000 years with the resources of the one-star system and additional 1600-1700 years with resources collected by the influence sphere. It might take a longer time, with gradually slowing down the growth rate. But overall it's limited by the speed of light, and after 6000-7000 years might be something like a 0.02% growth rate per year. Expanding with non-FTL more than at 1000-2000 years distance makes almost no sense except travel and information gathering and establishing a galactic transport system. I mean, further expansion - it makes sense for all reasons except solving the overpopulation problem. That's your [great filter](https://en.wikipedia.org/wiki/Great_Filter) if you wish so. [Answer] If the only terraforming technology we have is what we have today or think is achievable in the near future, we would not colonize our solar system at all. Not even Mars or the Moon. They are simply too uninhabitable. As it stands right now Mars will never have more than scientific expeditions. Much like on Antarctica right now. If we could somewhat easily terraform any planet to be earth-like, we would probably fully colonise our solar system first, since any trip to Gliese 667 would take 24 years or longer, given your method of travel which does not permit FTL speeds. [Answer] Coming late to this discussion. One thing that has not been discussed is a far simpler way to accommodate a large amount of people. Instead of trying to terraform other celestial bodies, we can do something similar with close to today's technology by just going underground. Everything that humanity has accomplished has been done by exploiting just the top 500 or so meters from the surface. If everyone moved to an area let's say up to 1,000 meters below the surface, there would be room enough to house many more humans (let's say 50 billion or more people for round numbers). You would need hydroponics (or similar) for the agriculture and Oxygen supplies. The main limiting factor would be sufficient clean water which would initially come from the surface. All the materials for supporting an acceptable lifestyle would come from materials excavated to make room for the habitats (AKA cities). With reasonable recycling, there should be enough for everyone to maintain at least a Western European lifestyle. With hydroponics, you are not subject to droughts, bad insects or other adverse growing conditions. Every growing season would be the best it could possibly be. The deeper you go under the surface, the more energy you can tap from geothermal. You should be able to generate 100KW/hr for each of the 50 billion people just through geothermal (that might be optimistic) plus "something else" that would be enough to host the people forever. Below 1,000 meters, you would need to spend exponentially more on climate control (esp air conditioning) to keep the temps at a level that humans can exist and thrive. That might the limit of depth for now. There are also possible problems with air pressure with diseases similar to the "bends" that may also be limiting factors. The surface could be left abandoned for the Earth to recover from humanity's abuses. I've read that if humans stopped emitting greenhouse gases, it would take up to 300 years for greenhouse gas levels to return to pre-industrial levels. Within 10,000 years, all evidence of humans ever being on the surface would be erased by natural forces. Building underground would be many orders of magnitude cheaper than trying to move billions of people to another planet. In 2019, it costs something like $10 million USD to send someone into low Earth orbit. We know this because the Russians sell space tourist trips to the Space Station that cost about that. And to get out of Earth orbit altogether, would be much more costly. Now multiply that number (whatever it turns out to be) by 1 billion people. This gets us a starting number of around $10,000 TRILLION USD. That's about 1,000 times the USA GDP for 2019. And that's price just to get the people away from Earth. Then you still have to land somewhere and build the habitats. As to WHY people would want to migrate underground, that is an open question. Could be some eco-catastrophe or it could be something else. That's up to the story teller. [Answer] ## Venus Venus surface pressure is not survivable. Massive sunscreen in orbit of Venus can cool it off, but to reduce the pressure is needed to take atmosphere out. Very complicated. Cooling the planet and put bacteria to make the atmosphere more suited to human life will help, but the pressure will still prevent people to live outside. It may be a big farm (provided plants can tolerate the pressure) and have people living in bunkers. The bunker-style colony does not allow for huge populations. ## Cold Moons The cold is a problem. Unless you invent some powersource that can heat up a planet, the colonies in the colder moons will be small. Bunker-style. There is an exception for Europa and Ganymede where the tidal force of Jupter heats up the moon interiors and lots of geotermal energy may be available. Huge power plants can be set on Io to take advantage of the geotermal energy and beam the energy to the closests moons. That is the exception. May support big habitats, but not even close to earth's population. Titan, for example is cold, too cold to have anything but a small outpost. And even a small outpost will be challenging. ## Terraformation Time Terraformation can take centures. Mars has to be warmed to make a denser atmosphere and then put bacteria and plant to convert the atmosphere. Venus has to be cooled down, massive sunscreens built on orbit, then put bacteria and plant to convert the atmosphere. I say between 200 to 500 years process. Actually terraforming may not even be feasible. The size of the mirrors needed to war mars and cool venus are huge. Possible the resources you civilization need to build the ramjets. ## The Key is Size In your universe the problem is population explosion. Mars, Earth's moon, Europa and Ganymede are small compared to the earth. Mars surface is a bit bigger than the size of Africa. Moon, Europa and Ganymede surface is smaller than Asia. Venus surface is almost the same size than Earth. In your universe, those planets can be in process of terraforming and still not being near enough to sustain the population you want. ## Earth's Moon Earth's moon is challenging outside mining and shipyards. Our moon probably will not support huge cities because the lack of water. However I heard about a far-out ideia to make an atmosphere to the moon, by hauling ice from comets and asteroids. I do not know if the calculations was correct but someone in the usenet claimed that the moon can retain a thick atmosphere, thick enough to breath, by about a million years. ## Conclusion You are working with Bussard Ramjet, seems to me that you universe is conservative on energy. That means terraforming will be very hard. Venus and Mars need to move lots of resources to make the mirrors and then wait a long time to the bacteria and plants do their jobs. Earth's moon requires a lot of ice to be hauled from the outter solar system. The Ramjet can put people in closest stars in a century. Terraforming takes a few centuries. And even then, does not go much further than doubling the habitable surface of our solar system. [Answer] The last line in your question adds immortality to the mix. This opens a variety of psychological motivations to the mix. It could be that there are several layers of maturity waiting for us in the three and four digit ages, where we might come to see the world completely differently than we did when we were "young". Children, Teenagers, Twenty-somethings and the other current age categories that we know about, each have distinct values and goals. Who knows what mental mandates might be waiting for us as the years go by. It could be that after ten centuries living among nothing but humans, it is perfectly rational to buy a Bussard-Ramjet powered Corvette and race off to explore the stars. Terraforming..? Leave that hard work for the young people! I have an entire universe to explore. [Answer] I guess interstellar travel and terraforming wouldn't be invented overnight. It would rather be a long process. Before going on a risky and expansive adventure light years away technology would have to be tested before more locally on the Moon, Mars or Giant planets' moons for example. Setting up scientific bases could be a first step then these bases could lead to industry (mining helium3 on the moon or drilling on asteroids for example) or tourism purposes. Terraforming strictly speaking might not be most suitable options in our solar system but colonization could be started and tested with underground/dome cities... In this spirit interstellar travel and colonization would only begin once there is a solid technological/economical base for it in the solar system. [Answer] Neither The general hard science consensus is that interstellar travel by human beings is impossible. (Also that Bussard ramjets do not actually work). If we ever get off planet in a big way (still as large apes) then the most likely first point will be our moon, because it provides resources at the bottom of a much less deep gravity well and with no atmosphere in the way. Yes, no atmosphere is a huge advantage for manufacturing materials and putting them into Earth or Solar orbit. The next stage will be O'Neill colonies. Then Asteroid mining Mars might eventually be possible to Terraform but that would be a long term project, and by that time humans would probably regard living at the bottom of a gravity well as hopelessly quaint. But I also think that "as big apes" is an unlikely constraint. I suspect that we will either create AI's that will expand into the universe while (hopefully) leaving us this planet with its hopelessly hostile wet oxidizing atmosphere ... or we will become those AIs, through some sort of mental uploading or seeding. And AIs should be able to down- clock themselves and reach the stars. Except as ever ... where are they? Fermi paradox, Von Neumann machine formulation. [Answer] This question is plenty of scientific answers that may answer the technical issues. But I would like to address the philosophical question about why would humankind go for interstellar before finishing the conquer of Solar system. Why are we spending more resources in knowing outer space than in our deep oceans? Because we are used to the things that are near and humans are always looking for the new. At the very moment we achieve the tech needed, we will try to go further, even if it is easier to stay. Also, I dont have a clue about society in your world, but the Cold War made us go to the moon. Maybe one macro-country wanted to show more powerfull than another by putting a flag in Gliese 667Cc. [Answer] Once teraforming is cheaper than habitat building, it makes sense to colonize planets. This way you can transport a bunch of settlers and have them colonize the planet on their own with resources from the planet (including Human Resources). It would come down to whether there will be enough habitable land post-teraforming to make up for the cost of doing so. Another consideration is agriculture, where depending on the starting elements within the planet it may be feasible to develop land for farming. I would say teraforming is pretty much the same as building a habitat on or near asteroids. The main consideration though is the supportable population. It's worth the increased cost of return trips due to gravity/atmosphere if the planet will be able to sustain a large population for an extended period of time. [Answer] There have been excellent answers on the technical aspects. Let me highlight: # Non technical reasons If we ignore whether or not colonisation will ever become possible, which has been well discussed, it is conceivable, that humans initially don't want to leave their habitat earth until well after interstellar colonisation becomes possible. That is, they stay on earth and just explore space without colonising it. Then social or medical reasons force them to colonise and choose as remote a location as possible. Assuming people don't die naturally, but can still be killed, such social reasons might be: ## External Adversaries If they are not the only the only space faring race, conflicts may arise. It may be prudent not to put all the eggs in one basket. At present the capabilities for both space travel and terraforming are absent, but the bombs needed to render earth a very ugly place are makeable! ## Internal Conflicts If population grows drastically, groups that want to pursue radically different lifestyles might grow in size. In order to isolate themselves from "the others" they might opt to go more than just a "galactic stroll" away. By galactic stroll I mean what is easily within reach of those days. ## Infections If the reason for the first big migration is an infection, you want to go well beyond the current reach of "every day space travel". ## Legal issues These first settlers are not Earth's best and brightest, but rather a group of hideous criminals, who would do well to settle outside all patrols of the earthlings of that age! [Answer] Given that there are lots of people, and only some of them will be colonising our solar-system, the second interstellar tech becomes available your analog of Elon Musk will make it happen asap. The colonisation of our solar-system will proceed without interruption while this happens, because of sunk-costs and long-laid plans. So, colonisation of a region will start as soon as the capability is ready, and will progress until it is no longer commercially viable. [Answer] Coming late to the discussion but... None of the planets in the solar system seem to inhabitable even with massive investments. The Moon's dust is lethal - it will shred plastics and organic tissues because it is very small, jagged, and wasn't oxidized. Mars is covered in perchlorates. Jupiter's moon are inside a particle accelerator (Jupiter's magnetosphere) with deadly radiation. And I haven't mentioned the issue of wrong gravity for human life. If you can travel to another star system with a reasonable world, that is, reasonable gravity, running water improving the dust issue, no funny chemicals dissolved in the environment, it may be better to colonize this faraway solar system then deal with the nearby worlds. The planets and moons in the solar system are last resort options. If you can build big rotating stations/ships or go to another system, they will be left underdeveloped. ]
[Question] [ ### BACKGROUND Fantasy setting, highly rural/pastoral. Social landscape is significantly more egalitarian (but far from idyllic) with no serfdom tying a peasant class to the land. Magic exists, but wizards, as a social class, are estranged from others and have little interest or incentive to meddle in the affairs of mortals. Technological level is intended to be roughly analogous to the first industrial revolution, and the setting is experiencing increased urbanisation and the rise of cities, but… ### QUESTION I’m in the early stages of working on a setting for a tabletop campaign, and I’ve hit a bit of a snag. As mentioned above, I’d intended for the technology level to be that of the first industrial revolution, but I’m having some difficulty envisaging how such a thing would succeed in this setting. There’s a number of political forces arrayed against them, but I think the tipping point would be the popular outcry against the smog and smoke generated by factories powered by coal. A second, perhaps even more important concern, is that on a meta level I feel having the city inundated with the kinds of pollution London saw would undermine the aesthetic I’m going for. Dark smokestacks belching out ominous black smoke should be reserved for evil wizards making their own little Isengard. So, I’m at a bit of a loss. I’ve considered moving the technology forward a bit to allow for electrical generators and grids, which would get rid of the the visible pollution (for the most part, pushing the power plant away from population centers) and handwaving away the in between steps, but I’d feel I’d be stretching credulity if I also wanted to keep the vibe of (mega)cities being a “new thing”. Also, on a very petty note, I’d be losing steam trains, and I do enjoy them. Am I overthinking this or is there an obvious solution I’m missing? Is there a way to maintain a bright, clean aesthetic without handwaving things and hoping nobody looks too closely? Edit 1: A couple of clarifications re: social landscape and scale of city Edit 2: Available feedback has helped me greatly narrow down my concerns and has been very helpful, thank you all. So, if no pollution is a non-starter, is there an alternate power source that would provide a cleaner aesthetic but fulfill the role of coal in powering engines? [Answer] ## Industry is not the issue The first factories were powered by water wheels, not coal; so, you can make your cities a bit cleaner by sticking with this. Ancient Rome for example ground enough grain for over 1 million people using just 12 water mills powered by the water brough in by thier aqueducts. They also had water powered saw mills that they used for mass producing plywood, and there is no telling how many other things they powered with the water they brought into thier city. That said cities were already nasty, polluted, smoky places LONG before the industrial revolution. The biggest problem is not the coal factories invented a few hundred years ago, it's all the wood burning stoves and fire places that have been around for millennia. If your industrial era city is not a smoky, nasty place, then it's not historically accurate... unless your city has a methane pipe system. Unlike wood or other fossil fuels, methane burns cleanly into just CO2 and Water with no ashes, tars, or other waste products so there is no visible or smellable smoke. It is also colorless and odorless (without modern additives to give it a smell); so, even if you have some leaking here and there, the pollution will not be apparent either. By 1816, Baltimore installed the first piped methane powered street lamp system and by the 1830s you start to see the first gas stoves being produced; so, this places piped natural gas replacing wood and coal burning well within the bounds of a late industrial era society. The downside of methane is that until very recently, it was only available as a byproduct of the coal industry meaning that many cities that burned methane in homes also burned coal in thier factories. To remedy this, it means you need to place your coal powered factories and such outside of town limits (or sell the coal to those evil polluted cities), and then pipe in the methane byproducts of your coal mining as a fuel for use inside of the city for cooking, heating, and light which will give you relatively clean air in the city itself. [Answer] There may be a bit of misinformation here. 1. Those "dark satanic mills" arose almost two centuries after the start of the Industrial Revolution. Industrialization began with waterwheels, and hydropower was the power source which drove the rise of factories for a very long time. 2. London was not typical, like, at all. The smog of London was mostly due to local climatic conditions and the universal use of bad coal for domestic purposes; factories did play some part, but they were not the dominant factor. For example, Paris, with different geographical conditions, never came close to London with respect to smog and bad air. 3. Feudalism is by far the most decentralized political system in human history. I am at a loss to imagine anything more decentralized than the High Middle Ages. 4. Electricity could have been discovered and used at any point in history at least from the classical age onwards. It is a bit of a historical mystery how come we had to wait for the 18th century. They had copper, they had zinc, they had iron, they had acids, they had wire: there was no material element missing. 5. But what I really don't get is the part about cities being a new thing. Cities are a really really old thing. Cities came five thousand years before the Industrial Revolution. Basically, cities exist to support trade; that's what they are for. Without cities, you cannot have the economic base where an Industrial Revolution can arise. And about the pollution, you may be overthinking it. You just cannot avoid pollution in the city, not with a pre-21st century technological base; but you do not have to dwell on it. To give a practical example, one of the most pressing pollution problems which faced 19th century cities was horse manure. London alone had about 150,000 horses towards the end of the 19th century, and each horse produced about 10 kg of manure per day, to say nothing about the smelly liquid waste and the swarms of flies. That's 1,500 tons of manure per day which had to be collected and carted out of the city. On the other hand, have you ever read a historical or fantasy story, or seen a film, where the horse waste problem was shown in its gross magnitude? No. It was carefully placed aside. Nobody wants to read a story or see a film about the problem of collecting and carting a thousand tons of manure per day. [Answer] You can't avoid pollution: just consider that algae and photosynthetic organisms polluted Earth so much with their waste gas to seclude anaerobic organisms into remote parts of the planet where oxygen can't easily reach. And algae are far away from anything resembling an industrial revolution. Getting to something closer to our context, early bronze age people heavily polluted their environment with the wastes of copper mining, increasing the local concentrations of arsenic thanks to the wastes of smelting. And, again, they were far from being an industrial revolution. You simply can't produce a lot of something without having also a lot of something else in the form of wastes and polluting agents. It's the amount in itself that turns the waste into pollution. [Answer] ## If you want a different outcome, you need different motivations If you assume a capitalism first approach, you should expect similar outcomes to our history. You don't have to assume that capitalists are evil, it's just that they will be more focused on profits and the downsides of pollution will not be changes behavior until it becomes obvious that the downsides are significant, widespread and detrimental. If on the other hand, the people have widespread honest respect for the environment, and this is truly considered as a first principle, then even those few that don't respect the environment will still take into account environmental impact because the consequences of becoming known as a polluter will be too harsh to ignore. Even then, if some people think they can get away with it, they will pollute as a shortcut cheap solution to waste disposal. However, the widespread pollution of London or rivers that catch fire should be rare due to a few bad actors. The short-term economic benefits of simple dumping waste to land, water, or air must be over-powered by the bad karma of doing so. Thus, the compulsion to be clean must be strong. Many people believe that the culture of the native Americans was such that they were in balance with nature. Though certainly not true in a universal sense, such a culture would be a plausible basis for such an outcome. [Answer] I suggest that you postulate different sources of fuel. For example, if there was a unique species of ballon tree that grows over coal deposits or swamps and extracts methane chemically from the coal or decay via the root system. This would form havestable sources of methane for your world. As another example, your world could be rich in magnetite for some reason, and the prevalence of magnetic sources led to the discovery of electricity as a power source before coal. Turbines could be water, wind, or animal driven. If there was some cautionary tale in the recent history of your world which led to a civilization-wide adoption of environmental responsibility "lest that tragedy repeat" could also help reduce the impact of industrialization. [Answer] TL;DR: Venice + Iceland for the win! Other answers have mentioned the two main sources of pollution in a London-like city at the start of the Industrial Revolution: coal/wood burnt to in houses, and horse manure. ### Iceland: cleaner energy source Burning coal or wood happens for two reasons: heating and cooking. You can mostly eliminate heating needs by relocating to a hotter area year long, and the little coal or wood used for cooking should not be much of an issue provided there's enough wind to disperse it. If you do not wish to go for a more "tropical" climate, however, another solution is a land with plenty of hot water underground that you can tap into. By redirected this hot water into houses, you solve the heating issue. There are villages, in France, where houses have used floor heating for a very long time, by piping naturally hot water into the floors; it really cuts on the heating bill. If the water is hot enough -- as in, scalding hot, or above 70C -- it will be free of any bacteria, and may thus be used as is for cooking. Given that Romans were building aqueducts and sewers in the Antiquity, an early Industrial Revolution society clear has all the technical know-how to pipe hot water from the ground. And should hot water NOT be universally available, it would explain why the city sprang up here, and not anywhere else: it's a prime spot to survive cold, harsh winters. ### Venice: cleaner transportation You can eliminate a lot of horse manure issues by switching from land-based to canal-based transportation. A horse (or other) is nigh required to pull a cart because the cart is so heavy, however the same load can be transported by boat fairly easily -- especially in the absence of current. A city ala Venice (or Amsterdam, or Copenhagen) with an array of canals criss-crossing it would be more likely to rely on boat transportation than horse-drawn transportation, at least within city limits. ### Combination Combining the two will require a specific geographic location. Thermal "hot spots" are most likely found in mountainous areas, so the city would likely be in the mountains -- though it may be close to the bottom on the nearby plain. Canals require a plain, and likely a slightly "spongy" one (marshlands), close to a source of water -- be it river or sea. A city combining thermal "hot spots" and canals would thus likely be located close to either river or sea, in a flat "marshland" area, with hot water being piped from nearby mountains. [Answer] Several other answers have briefly mentioned methane. Perhaps your world's industrial revolution is centered around farming and breeding microorganisms that turn farm waste or other organic materials into methane fuel; this would also clean up the natural smoke and dirt of a city that burns wood or charcoal for its fuel. (Smoke from indoor fires is a significant cause of health issues in pre-industrial or partly industrialized urbanized societies, even if the fuel is wood or dung.) This science article for kids has a good overview of biological (anaerobic decay microorganisms, cattle farts, ) and non-biological (mostly volcanoes) sources of the methane in our environment, though you could make your planet be a bit different: <https://kids.frontiersin.org/articles/10.3389/frym.2019.00133> This rather technical article discusses some of the ways that methanogenic archaea can be, and are being, used to generate methane which is burned for electricity and or purified and compressed into transportation fuel: <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7289024/> The biggest issue here is how to trigger initial uptake of these technologies. We learned to burn coal to smelt iron because there were places in the world where small coal and iron deposits were close to or at the surface, and easy to access; only once the technology was proven at that level did we start mining more inaccessible deposits at the scale needed to drive a full scale technological society. One possible scenario would be clay deposits in bogs, where people learned to use the methane from the peat bogs to fire clay objects on the spot. This article talks about how some bogs have a clay layer underneath them and others do not, though it is mostly focused on using bogs to grow cranberries: <https://www.cranberries.org/exploringcranberries/into/beneath_back.html> Hopefully this gives you some ideas to start from. [Answer] A bit more fantastical - what if uranium was exceedingly common in your world? Wood stoves are replaced with tiny RTGs, and there are myths or experiments with larger ones with occasionally terrible consequences. Of course, people have developed some resistance to radiation, but not full resistance. The evil wizards know this, moved to coal, and is in-part why they have “supernaturally” long lives compared to commoners. That lifespan difference can even serve as an added friction between the two groups. From the outside, the nuclear people would have almost no pollution. Just some magic stoves and increased illness rates in a time when illness is already rampant and poorly understood. ]
[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/249153/edit). Closed 4 months ago. This post was edited and submitted for review 4 months ago and failed to reopen the post: > > Original close reason(s) were not resolved > > > [Improve this question](/posts/249153/edit) [![The Lighthouse at the end of the world](https://i.stack.imgur.com/DDh9p.jpg)](https://i.stack.imgur.com/DDh9p.jpg) My world is dead and mostly unexplored. And at the end of the known world, there is a beacon which serves that singular purpose: warning anyone approaching that beyond this point, there is nothing else. ## This is no ordinary lighthouse It is unconventionally designed. Because, instead of a rotating fresnel lens, it uses a vapor lamp which is switched on and off in patterns to form its navigation signal. This means the light turns on, and off, all day. All night. Forever. But WHY would it be built this way? Logically? The keeper of this light goes insane, for several reasons. But the light itself ultimately breaks him. Instead of a quietly sweeping beacon scanning across the horizon peacefully like most lighthouses, the light has been designed as I have stated. It completes a pulsing pattern of three repeating flashes. The mechanism uses old electrical “valves” to connect the high powered arc lamps to their circuit, then disconnect it. The sound of the valves is the what is needed in my story. It is incessant, and inescapable. With help from many other factors, this tik-ah sound finally drives my character mad. I had written the story and the effect really worked. But only after did I think about it; lighthouses with a rotating lens are almost silent. I know lighthouses don’t normally use this switching mechanism. But the story is done, and it’s awesome. I only need to justify this unconventional mechanism somehow, possibly by geography or topography (hence the title). Energy considerations? I don’t know. My thoughts lean toward some unique requirement in the light that it must shine only in certain areas, and not in others, or maybe it has to reach some points simultaneously which a sweeping light can’t do. ## Q: Why would a lighthouse choose a flashing beacon instead of a rotating beacon? Most lighthouses use rotating fresnel lenses, gapped to form the pattern as it sweeps the horizon. Lightships, I believe, may have used flashing beacons. But what factor might lead to the decision of a valve instead of a rotating fresnel lens? ## For what practical reason did a lighthouse use noisy tech that is drives my keeper mad? ——— # Story snippet Here is part of this chapter, showing the effect the light has: — “OSCAR OSCAR, We have ze supplies. Nitre, one thousand two hundred gallons. Water, two thousand five hundred gallons. Do you hear?” “Aye.” A pause on the radio. “Fire bucket, ten. Lamps, twenty-four. Wrenches, forty. Standard sizes. Cable, eight hundred feet. Gyros, eleven.” Another pause. “Do you hear?” “Aye.” Another pause. “Books, thirty seven. Clothes, …” “Which books.” “Pardon?” “You ‘ave Dostoevsky?” Pause. “Que?” “You ‘ave the book, ‘bout the brothers?” “Attendez une minute” pause. “Oui, ze book is here.” “I be ready.” “Bon.” Radio noise from the room continued as the pilot and copilot spoke. The man listened, curiously. They were not speaking to him, they were speaking French. They forgot to shut off the radio. “Quel travail misérable.” More French came across which he did not understand, but it was apparently funny. He pulled a large lever to turn off his radio. Electric filaments began to fade from its tubes. The man walked to a door. A crucifix hangs above it. He pulls back a long lever along its side. Locks along the edge are linked together, and turn in unison to release the door. Opening the door, a Steam engine pumping sound grows louder. He walks into the room, the light blinks in threes with the sound: Tic-ah tic-ah tic-ah. Tic-ah tic-ah tic-ah. He takes down a large pair of trousers in a heavy fabric. He puts his legs into them. He sits on a bronze bench and puts on heavy shoes with large, wide soles. The pulsing lights continue in threes. He picks up a large jacket, and takes two metal bottles. He clips them into the inside of the jacket, they let out a fading hiss. [Answer] # The beacon is directional. Rotating lenses are great if it's safe to send the beam in all directions equally. It's also fine if part of the arc can be blocked to cut the pattern in that direction. They're less good if you need "3 short pulses from 0 to 45 degrees, 2 medium pulses from 45 to 90 degrees, and on constantly from 90 to 180 degrees" (there are some combinations that could be achieved through clever use of a rotating lens assembly and some blocking material, but plenty that either couldn't be or where the gearing would be highly complex). Thus, you don't have a single beacon, but you have several, each pointing in different directions. Each light is controlled by its own set of "valves", which click incessantly. Originally, that was a design feature: the lighthouse was designed with the idea that an automatic monitoring system would listen to the clicks and watch the lights, making sure that everything was in working order. That system broke down. While awaiting repair, the soundproofing was removed so that the keeper would be able to hear them and note any deviation. Since then, the funds to repair the monitoring mechanism have never quite materialized, so the keepers are slowly driven mad. On the plus side, they're really good at listening for deviations to the click pattern. Why not have multiple lights with their own rotating lenses? The monitoring system: either its "eyes" would need to be too far away from the lights to ensure that they didn't "see" other light sources or they would interfere with the rotation system of the lenses. # The lighthouse is a lure. The lighthouse wasn't actually created by the denizens of the Something, but by the Nothing. Much like an anglerfish, it was intended to draw those of the Something to the border of the Nothing so that the Nothing could draw sustenance from the Something. The organization that operates the lighthouse for the Something are well aware of this fact. They choose to sacrifice one or two minds to the Nothing every couple of years; doing so keeps the light active (thus keeping others of the Something away) and keeps the Nothing sated (at least, for now). # Why not both? The former is the official reason, the latter is the real reason. [Answer] ## You are behind the times Before modern day rotating beacons were used because there either were no way to turn light on and off relatively quickly and repeadetly (for light produced by burning fuel) or it would greatly shorten light source lifetime (for filament bulbs), so periodically blocking the light by a rotating structure was the best solution at the time (light itself doesn't rotate, blackout structure and focusing lenses are). Modern lighthouses use static LED arrays which are turned on and off periodically. In addition they are mostly unmanned and solar-powered, with batteries which are charged every day to allow function during the night with a diesel generator as a backup source. Most lighthouses either already did the conversion to flashing electric lights or are in line for conversion. Ones that remain either have a historical importance or are a popular tourist destination. ## For your needs, you need blinking design to be more robust than rotating one. As design without moving parts is inherently more reliable that one that has them, your only problem is reliability of flashing lamp vs constantly burning. And there lies the problem: incandescent lamps hate on-off cycles. Your arc lamps (I assume that they are built like HID lamps) are not better, since the highes wear occures when they are reignited before completely cooling, blinking kills them fast. You need to make lamp resilent to constant cycling somehow for static blinking design to be preferable to rotating one. Or maybe rotating mechanism is for some reason less reliable, so it is better to replace lamps regularly than to constantly repair rotating system. Or you have to maintain a specific light characteristic (sequence of specific length on-off pulses which makes a light identifiable, actually used in navigation) to aid navigation. Which is easy to do with blinking light, but hard to do with rotating system. [Answer] I've got two/three answers to why the Lighthouse keeper goes insane. Not going to comment on the design of the Lighthouse though. The Mechanism of the Lighthouse is at a specific frequency that interrupts normal brain waves This wasn't a conscious design choice, it was a freak chance that the combination of Valves and the frequency of the electricity creates an effect in the Lighthouse keeper. It disturbs the Brain waves, not enough to be fatal, but enough to interrupt sleep. Slowly, over time, these disturbances grow more and more (due to the longer exposure) and start to manifest symptoms of Madness, this causes a sort-of accelerating effect where the Brain is producing it's own hallucinations, that themselves are further distorted by the interference. Starring into the Abyss, the Abyss stares into you I think that's a Nietzsche quote, or at least, some paraphrase of it. You said the Lighthouse is at the end of nothingness. No matter what the Lighthouse keeper tries to do - they will gaze into Nothingness. Not like merely empty space - but actual nothingness. First it might be an accidental glance, then perhaps a fleeting look, then as time progresses and their self-control and resistance starts to fade, they will look longer and longer into the void, their sanity pouring out of them as the Human Brain cannot comprehend true nothingness. It's not actual Nothingness... or at least not that we can comprehend There are things... In the Dark... Ancient things... Malevolent things... Things from a time and place that has long since been forgotten. They live beyond time and entropy, in the void in blackness and they can see us, in our world full of light, corporeal form, energy and emotion. And they hate it. They would dearly love to invade our world and suck everything from us, but they cannot. See, the Lighthouse has a secondary purpose... It keeps them at Bay. It's the reason why it must be maintained, it's the reason why one unfortunate has to sacrifice their sanity to keep it running. But although they cannot traverse past the Lighthouse... They can whisper to the Lighthouse keeper, in their dreams, calling them to look into the void, to see the manifestation of timeless hatred of life. [Answer] A rotating beacon with a lens has several benefits. The lens bundles the light into a bright beam, increasing brightness and reach. The rotation sweeps the beam in a wide arc over the horizon, covering a wide arc of sea. Several factors could offset these benefits: * a rotating beacon needs to run smoothly, maybe dust/sand in the atmosphere makes bearings hard to maintain and prone to failure. * a rotating beacon can only flash in simple periodic patterns. If you want a complex pattern, like a whole message in morse-code, you will need relays * If the light is for air-ships you cannot focus a beam on a single height like on the sea, you would need a special lens to focus a slit spanning from ground up in the sky. A relay might be easier. * depending on the energy and light-source you might be able to produce very bright short pulses with capacitors, while a traditional rotating beacon uses a permanent light source If you include the capacitors, they can also emit a high-pitched whining noise while charging - static electricity building up in the air. You can almost taste it before each bright flash of the light (like flash in old cameras). And you could also use a complex pattern of light flashes (aperiodic, so off-world travelers will know it is not a natural phenomenon, but a deliverate signal) [Answer] # There's something about the bulb It's built by a mad engineer, with a requirement that it run on as little power as possible. Some massively impractical abuse of physics later, and he has a flashing bulb, that works on completely contrary priciples. It lights things by emitting photons, as normal, for a flash. Then by some unexplained process, reversing the flow of entropy, or time (left unexplained by the protagonist, who is not a physicist), it drags all those photons back, recapturing the energy. It also has the benefit of stopping the Nothingness from engulfing the lighthouse, by undoing the damage each reversal, but has the downside that the keeper watches a consistent tearing away of a large chunk of reality, and then seeing it restored on each gap between flashes. From a proper physics perspective, it doesn't make a lot of sense - but for a Lovecraftian horror, it might work. You'd see tendrils of nothingness strip away and decay bits of the tower on each flash, and then the gap between flashes drag the pieces back together. The lighthouse keeper is completely insane, not just from watching this, but also from being partly or completely destroyed by the Nothingness, before reappearing again seconds later. [Answer] # Why the 3 blinking lights? This is a thing we do in real life. Modern communication towns have blinking lights on them at evenly spaced heights. The blinking means that the lights consume less power than if they stayed always on. When you need a light bright enough to be seen from many miles away, a blinking light can give you much more reach than a solid light of the same power usage, and blinking is also more likely to catch someone's attention than a solid light pattern which further increases your effective reach. The spinning thing that older lighthouses did was to send out a directional light sweeping across the sea (again, for maximum reach), but when creating a beacon for aircraft, you don't want a directional beam of light because you don't know what elevation to aim at. So, an omni-directional light that blinks is the preferred beacon method for aircraft which is what this lighthouse is meant to serve. The reason there are 3 lights is because of how tall the tower is. Communications towers that are tall enough to reach into low air space are supposed to place lights about every ~45 meters. This is because at night, you can't tell how far away a light is, but if they are a known distance apart, you can tell distance by thier spacing. [![enter image description here](https://i.stack.imgur.com/tPQMs.png)](https://i.stack.imgur.com/tPQMs.png) # Why is the lighthouse keeper driven mad? ## The sound of the light creates a Shepard Tone [Shepard tones](https://en.wikipedia.org/wiki/Shepard_tone) are a pattern of sounds that increase or decrease over time in such a pattern that they start and stop exactly one octave apart. So your lighthouse has 3 lamps. As one lamp starts up, the sound starts low and slowly increases in frequency until it fades off one octave later and shuts down. But each of the 3 lights are staged 1/3rd of a cycle apart. Because the brain has a hard time differentiating two sounds that are one octave apart, it makes the sound appear to continue to increase in frequency infinitely until your mind perceives the existence of a sound so high pitch that it actually exceeds the limits of your ears to hear. While a descending Sheppard tone can be calming, the kind that goes up in pitch like this has been reported to cause considerable anxiety and panic attacks after just a few minutes. A person who had to live day-in and day-out listening to an ascending Shepard tone would very likely develop a severe anxiety disorder, and anxiety disorders are linked to certain schizotypal symptoms like hallucinations and paranoia. ## And/or he is alone Humans are not meant to be alone. Whether the sound of the lights themselves are a major issue, lighthouse keepers who live by themselves, cut off from the outside world, are at a severe risk of solitary confinement disorders. When placed in solitary confinement, humans often exhibit a wide range of mental health problems including: [anxiety and stress, depression and hopelessness, anger, irritability, and hostility, panic attacks, worsened preexisting mental health issues, hypersensitivity to sounds and smells, problems with attention, concentration, and memory, and hallucinations that affect all of the senses, paranoia, poor impulse control, social withdrawal, outbursts of violence, psychosis, fear of death, self-harm or suicide](https://www.medicalnewstoday.com/articles/solitary-confinement-effects#mental-health-effects) So, even if the sound of the lighthouse itself is nothing extraordinary, it could easily become a fixation for his isolation induced psychosis leading him to believe that it is the source of his growing madness. [Answer] # The beacon does not only emit light The mechanisms you describe for controlling the beacon could also (and with all likelihood without careful design would also) generate a great deal of broad spectrum electromagnetic radiation. If the light operates on some sort of spark-gap mechanism for switching on and off, perhaps this same spark gap is being used to generate a radio/x-ray/light/infrared/etc pulse as a warning for systems that can't sense the light as easily. As a plot device this may be additionally useful: * The X-rays may cause all sorts of other problems within and near the tower (or motivate careful shielding for certain areas). * The radio signals could make communication near the tower very annoying (not only can the operator hear the click, he can hear the amplified click on the radio). * As people approach the tower the interference would get louder - perhaps a nice warning of their impending doom. Even if they can't see the tower they could be picking up a increasingly loud click on their radio. * A remote location could monitor the tower for correct operation even without direct line of sight by monitoring the ionosphere reflection of the radio pulse. [Answer] Strobe light The brightest lamp they have technology to manufacture is a strobe light, such as xenon flash tube. Depending on the atmosphere, it might even not need a lamp but use an artificial lightning bolt. Because the lamp can be illuminated only for a bright flash before a second or two of recharging, it necessarily has to blink and there is no point having a rotating lens. ]
[Question] [ There is a world where giant monsters the size of mountains come every few hundred years and destroy huge amounts of the world and any organized civilization of humans. The only effective response countries have found is to build giant mechas the size of mountains to fight them off. The monsters target particular regions, and each region has a certain number of giant mechs to fight them off. Fueling them requires perhaps 30% of the country's output at a rate that isn't easily increased by technology since their enemies are also advancing. How could a society ensure they keep devoting those resources for centuries? I've seen repeatedly in real life politics that there's a lot of pressure to lower spending and to focus on the now and not the future. Any nation that wants to have more welfare, or to conquer rival nations, or to help mitigate a famine and drops below 30% won't have the mechs fueled, and will be annihilated. If you use the mechs on rival nations then you need to devote even more resources to refueling them. How do you ensure that you can do a public service project that takes centuries and drains a huge amount of national resources, labour and time without it being stopped by any opportunistic people? [Answer] /Any nation that wants to have more welfare, or to conquer rival nations, or to help mitigate a famine and drops below 30% won't have the mechs fueled/ Multipurpose mechs! The peacetime gig for these battle mechs is farming and fishing. The technological improvements needed to keep up with the monsters mean that the mechs are great now at what they do and so famine is not a problem. The people are actually quite well fed and robust. Mechs also do construction building cities, dams and other works. Oceangoing freighters and overland trains - both cargo and passenger - are also giant mechs. As regards war, mechs also excel at conquering rival nations, especially those that have not been keeping up their mechs. Sometimes the conquerors take their stuff and destroy their mechs and then monsters come and eat the people. But sometimes the wise conquerors add the people and mechs to their own lands and so become stronger. Over time there is consolidation of nations into those that are the best at mechhery. Mechhery is what one calls it - the art of meching. Thus the 30% spent on mechs is not exclusively for fighting giant monsters, but advances the general welfare in many other ways. [Answer] # The Eisenhower Paradox: FRAME CHALLENGE: The idea that economic prosperity is contrary to good defense spending misses a critical detail. Defense spending requires a massive industrial base, a huge economy to support it, and an undamaged nation NOT devastated by war to build and maintain all the weapons involved. Dwight D. Eisenhower knew when he became president that he could get the USA behind a program to build weapons to battle the USSR. But he elected instead to invest in the buildup of the US economy so the nation was more ready for supporting future military spending without bankrupting the rest of the economy. [![highway](https://i.stack.imgur.com/5Z6lN.png)](https://i.stack.imgur.com/5Z6lN.png) The Soviet Union sought to build and maintain a huge war economy for decades, and even they knew they had to invest in industry to support it. But their constant spending on weapons production meant that the overall economy suffered as a result. Despite NOT fighting WW3 with the west, the Soviets kept their system together. The existential threat of Soviet invasion served as a pressure to keep the west invested in their military. Both sides benefited in terms of military preparedness by the constant posturing and numerous small wars that pushed innovation forward. The massive spending on military technology could have probably created higher growth rates on its own, but there would likely have been less public investment in technology WITHOUT the constant threat of war. There were benefits from the technologies developed to support the military-industrial complex, which helped the development of technology throughout the nation. The interstate highway system was developed at least in part to allow movement of troops and evacuation of cities in the event of war. So to ensure that the spending on the military keeps up without a break, you have the HUGE and well-understood not-so-existential threat of known periodic attacks. Spread the production of weapons, parts and power systems throughout your economy, and everyone will have some benefit from the continued spending. Efforts to reduce the impact of the battles and power consumption (overpowered power systems, huge "high speed" trains to move your mechs, duplicated industry in case of damage, agricultural stores to counteract devastated land) will all benefit from the massive infrastructure investments taken to prepare for these battles. So the wealthy nation is the one that lavishly invests in being ready for war, yet doesn't overly fixate on the mere building of weapons. Because war requires an economy, not just a giant killer robot. [Answer] Religion. A few select elites at the top know the truth and actually care. Below them preachers teach people from an early age that God requires proof of worthiness by building these machines. The bigger and more powerful the better to show devotion. Fuel and metal resources on the planet are provided by God primarily for this purpose and other uses are the wasteful ones unless they somehow advance the main goal. The rewards will be reaped on judgement day when God sends plagues to cleanse the unworthy and only the most zealous may carry on to the new world. Alternatively demons come from the underworld and God protects the true followers. Historical sources and evidence (cracked mountains, desolated areas, monuments, and battle scars on the mechs) would serve as proof of the core tenets. This also opens up for a sub story of well meaning revolutionaries who want to overthrow these "oppressive elites", adding tension and uncertainty to the story and perhaps the reader. [Answer] Three Little Pigs After a devastation period, remnants of nations emerge from ruins and swear that they build defenses from kaiju. Over few hundred years, most nations fall into complacency and decrease their defense spendings. All but one nation, which for some reason (religion, dictatorship, vivid legends about monsters told to every child) keeps on with the original plan. Then another wave of monsters strike. All nations got wiped out - all except one, which is able to keep the monsters at bay. After monsters are defeated, other nations should be quick to realize that defense spendings should never have been lowered. After a few cycles, only "responsible" nations are left in the world. Survivors from less responsible countries just can not rebuild by themselves and had to seek help from their more successful peers. [Answer] [![Clear and Present Danger](https://i.stack.imgur.com/G1Fat.png)](https://i.stack.imgur.com/G1Fat.png) Spending on Giant Monster Defence has the same issue as spending on Environmental Defence. [![enter image description here](https://i.stack.imgur.com/WjlbLm.png)](https://i.stack.imgur.com/WjlbLm.png) > > If we don't devote X of the economy to renewable energy the polar ice caps will melt and all your great grandchildren will be killed. > > > Likewise the Monster will attack in 200 years when we are no longer here. It is hard to take heart preparing for such a thing, and doubly hard to campaign around it. > > Vote for me. I will build electric cars. The benefit will not be visible in your lifetime . End transmission. > > > Of course once the monster tears down our walls and starts eating you cousins like termites, once the sea level rises and covers Los Angeles, people will suddenly react. But by then it will be too late. To fix this I claim Los Angeles is already underwater. The Monster is already out there. Look at him there, hiding behind the ruins of Texas. He rampages around the countryside. We follow him with unmanned helicopters with video cameras. You can follow his progress online or on our App. You can choose your favourite Giant Monster and buy our Trading cards. The monster is rampaging in the countryside where we can all see him. He attacks a something every few years. And every few decades he does a little attack on our city. The mech easily drives him off. Of course we don't NEED the mech for these little attacks. A few tanks or a cruise missile would be enough. But it is great for morale. The attack is televised and everyone gets to watch our mech do sicknasty high kicks and karate chops. Then we get the day off work to celebrate. It's only every few hundred years when the monster enters a mating frenzy that he will attack our city and fight to the death. That's when we need the mech at full power. [Answer] ## Frame challenge: This is epistemically impossible. Any world where the people have sat down and figured out that 30% of GDP will be necessary to prevent a monster attack also has data that that 30% figure was based on. This must necessarily include monster attack frequency and knowledge of how fast they are advancing in power. A similar argument regarding the knowledge that giant mechs have been effective applies. 30% sustained is a total war economy. Total government spending in most developed countries is 40% or so. Without damn good proof that the attack is coming, no one would ever even think to spend 30% in the first place. [Answer] OPTION 1: LAG TIME Don't put the kaiju in the future, put them in the NOW. In other words, the kaiju show up on a weekly, possibly even daily basis, and if you cut funding to the mecha program for absolutely any amount of time, you're \\\\ing dead. OPTION 2: IT DOESN'T As @StarfishPrime stated, we have an unfortunate tendency to be brainlessly short-sighted idiots who would rather be comfy now than alive more than a year from now. In other words, you basically end up with a post-apocalyptic situation where organized civilization has been completely annihilated. OPTION 3: DON'T FIGHT THE PROBLEM, AVOID IT Construct massive bunkers that allow humans to hide while the kaiju wreck stuff, then come back up once they go away. [Answer] ## Frame challenge #2: A fixed, identical long term % of GDP for every country for centuries is not possible. A fixed quantity % of GDP ignores how exponential growth works. This is the same idea underpinning the Eisenhower paradox answer but I want to put it more forcefully. US GDP per capita is ten or a hundred times that of some other nations. If Turkey needs to spend 30% of GDP on mechs, the US only needs to spend 10%. If country A and country B start off with the same GDP but country A grows 1% faster in real GDP for a century, the end result is that country A has 270% the GDP of country B. Saying every nation has to spend 30% is equivalent to saying every nation has exactly the same GDP per capita and exactly the same growth rate for centuries. That's not possible, or at least, not at all plausible. ]
[Question] [ Closed. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Add details and clarify the problem by [editing this post](/posts/167986/edit). Closed 3 years 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/167986/edit) Mentioned in various spots in the Bible, the Leviathan is described as a colossal serpentine creature. It is very heavily armored, able to thwart most types of melee weapons, along with some low-velocity projectiles. In addition, it is capable of breathing fire (or acid, depending upon which translation you use), allowing it to pretty badly mess up any human force which dares attack it. As such, it is best described as a "bioweapon"; whenever God wants to mess up some particularly obnoxious unbelievers, He sics the Leviathan on them. ## The Question: Since the Bible et al don't really describe the Leviathan in greater depth than I have already described, my question for you is this: Given these features, what would a God-crafted Leviathan be like physically? A good example of the type of answer I am looking for is @IndigoFenix's answer. It does a pretty good job, but I am still interested to in what the rest of you think. "Evolutionary pressures" are not a concern; This is the Judeo-Christian God we are talking about; He is omnipotent, and thus doesn't need to mess about with evolution when creating His ultimate bioweapon. Nota Bene: I realize that there is a [similar question](https://worldbuilding.stackexchange.com/questions/167923/anatomically-correct-leviathan) out there; however, this is different. That question assumes evolution as a cause, this question assumes that Jehovah created it. A Final Nota Bene: I am looking for a creature that is biologically feasible. This means that, although supernatural means were involved in its creation, it cannot depend on magic for its continued existence. [Answer] ### A Thermosynthetic Giant Deep-sea creatures aren't nearly as restricted by the square-cube law as terrestrial ones; as long as they are made of meat the water can support their weight. The biggest problem oceanic giants have is maneuvering and getting enough to eat. So I'd say the easiest way to handle this is to not have them eat at all. [It is hypothetically possible to create an organism that feeds off of heat gradients directly, converting it into chemical energy to use later using microscopic mechanisms conceptually similar to a steam engine](https://en.wikipedia.org/wiki/Thermosynthesis). The reason why this never seemed to take off on Earth is that heat is tricky and inefficient to work with on small scales - the heat differential between one small-scale region and another is not very high, so any hypothetical thermosynthetic microbes that may have existed were easily outcompeted by more efficient chemosynthetic and photosynthetic microbes. No successful thermosynthetic microbes means no thermosynthetic multicellular organisms. But since we're talking about intelligent design, we don't have to worry about that. For capturing thermal energy, [the ideal design is one with a huge difference in the heat levels between one end of the generator and another](https://en.wikipedia.org/wiki/Geothermal_power). A colossal serpent is perfect. It leads a mostly sedentary lifestyle, with one end of its body buried deep in the earth, possibly by drilling into undersea volcanoes. The other end of its body is exposed to the cold water of the deep sea. Using efficient molecular and macroscopic organs along its body that would put our clunky steam engines to shame, it draws boiling water through its internal vessels, capturing every bit of thermal energy and converting it into fat for later use. [It also has loads and loads of DNA repair mechanisms](https://www.nationalgeographic.com/science/2018/08/news-cancer-elephants-genes-dna-new-research/), to keep it from getting cancer despite its immense size and nigh immortality. Whenever God needs it to terrorize Egyptians, eat Jonah (it has an isolated gas bladder for such a purpose, it can fill it up by gulping air), or just show off, it pulls itself out of the ground, swims around using its stored energy, and then returns to its resting/feeding place when its Job is done. Fire/acid breath and heavy armor are no problem once you've got the energy problem handled - hard scales can already deflect bullets and harpoons, and fire breath is easy if you ignore evolution, especially with all those lovely volcanic chemicals like sulfur and methane it will be accumulating over its lifespan. It can even incorporate iron into its physiology by absorbing iron sulfide like the [scaly-foot snail](https://en.wikipedia.org/wiki/Scaly-foot_snail). [Answer] Actually, it's not that hard at all. Consider the Basilosarus (which is a proto-whale, despite the name, not a reptile). It is one of the largest known animals to ever exist, and is the largest extinct animal known following the extinction of the dinosaurs (only the modern Blue Whale was larger, at 98 feet compared to 66 feet of the Basilosarus). Most renders of this animal give it a more serpentine look in the hind region, and it still had two visible hind limbs in the form of smaller flippers to the forelimbs (all modern whales technically have hind limbs though they only exist in the form of vestigial bones. Even snakes still retain limb bones to some extent). Acid "breath" is easy to duplicate, as the human stomach houses some of the most acidic substances to break down food for digestion. It's entirely possible that your leviathan uses a controlled regurgitation of stomach acids as a defense mechanism against large prey. They were also hunters and would definitely be the "bigger fish" no matter what they ate. It's reasonable to suggest it evolves to be even larger (the reason whales can get so big is that water is one of the few substances that is at it's densest in liquid form, which means that it's going to support any "mostly water" weight floating in it, allowing animals to by-pass the typical limitations on size that are inflicted by the Square Cubed law (if you double an object's size, you will increase it's mass by 8 times.) This causes all sorts of problems in living animals, as they can't get enough needed elements like Oxygen to satisfy their new mass, nor can they expel that much waste products. To top it all off, their support structures aren't capable of supporting the mass. You can notice the effect of water on your limitations if you've ever been in a pool and got into a dunking fight. You can easily lift your buddies and even some of the ones who are larger than you because the muscles used to move your body are overpowered in a dense surrounding fluid like water. [Answer] As Absolutely Badass as God Wants The whole point of leviathan is that it is a symbol of God’s supremacy over nature. Let us assume that God isn’t going to bend the laws of physics around the Leviathan for the sake of the discussion. Being an aquatic creature would mean that it wouldn’t have to worry about weight, so it can get really big. It would only be limited by caloric intake and some issues with circulation Since it’s a custom creature evolutionary pressures aren’t a concern, so it gets the full works for fire breathing, ultra dense muscle, rapid cell healing, hardened scutes and osteoderms. It’s implied to be reptilian like in Job, so picture a gigantic crocodile or mosasaurus. [Answer] You're a god. You came to this nice planet. It already have large as a log alligators. And snakes. Oh my me what kind of a snake this is. You take green anaconda or male saltwater crocodile. Take crocodile. Because Egypt. God like those pyramids, they're nice. All you do, as a god is to give them venom that interact with the brass weapon and "melt it with acid". But god is lazy. He take 6 days and call it a week. So he takes nitrate, which is a "common" thing in Egypt, usually used for mummification. Make the crocodiles hunt for prey around nitrates storage (or eat "fresh" mummies). Crocodiles don't consume nitrates, but rather store it in their mouths, making it into pulp which they then puke on offending humans. Nitrate corrodes (melts) brass. Crocodile leather is quite dense so a brass dart, jawelin or hook can not make a lot of harm to it. Oh, and btw, nitrate is not so good with corroding steel. So that's why there are no more "leviathans"; they were hunted down with better weapons. [Answer] The question you’re essentially looking for is, "how can a creature with said attributes realistically survive?" Short answer is, it can't. You can’t just plop down a creature and expect it to survive. Even if it’s capable of surviving, it won’t last long, as it will need to consume a vast amount of energy just to sustain its needs. The creature is not capable of evolving into existence. That being said, let’s try to pick apart what attributes could stay with the leviathan without it being killed off, using earth oceans as a example. > > colossal serpentine creature > > > This isn’t likely. Its body is so colossal that it will need to eat a vast quantity of food per day, so this would be a death sentence for the creature. As a result, its body will have to become smaller. > > it is heavily armored, able to thwart most melee weapons and low velocity projectiles > > > Now this can be kept, because it provides protection against a wide range of sea creatures. However, strength sometimes equals weight, which further equals slowness, which leads to being more susceptible to being attacked. > > capable of breathing fire or acid > > > Breathing fire is possible, although it would require a lot of force to to be exerted. Breathing acid is more feasible, so removing fire breath and replacing it with acid breath will make the Leviathan much more realistic. --- # Overall The creature would look pretty different. It will be a smaller, more serpentine like creature that is arguably slower in speed. It will most likely reside deep down in the ocean, in order to justify its armor. Lastly, it will still be able to breath acid as a defense mechanism. With all these changes, human forces would quite easily defeat such a creature, depending on how small it’ll need to become to actually survive its environment. That being said, I most likely missed some things, and I’ve probably got some things utterly incorrect, so this answer is most likely not the one your looking for. ]
[Question] [ Added 9-15-19: Thank you all for your comments. I will be reading them through carefully. I have quickly skimmed through the answers and I do appreciate your corrections on terminology and ideas, and my equation. After I've had a chance to think through all the comments and answers, I will revise my questions and post more to see if what I put together holds up to your knowledge. Angela In my story, I have an orbital ring around Earth at geosynchronous orbit, supported by and/or connected to a series of space elevators. I have already taken care of materials, purpose, and other issues. My question is whether the ring is in free-fall orbit, so that the conditions there are zero-G, or whether because the ring is 'attached' to Earth, there will be a gravitational pull towards Earth. If there is a gravitational pull, how strong is it? Would you use the normal gravitational equation F=GMm/r2? And if so, the mass of such a massive structure will make this an interesting calculation. Would this also depend on how the ring is linked to the elevators? Thank you. [Answer] You described the ring as "orbital" and "at geosynchronous orbit"; therefore, it's in freefall. That's what "orbit" means- in freefall, but moving sideways so fast you miss the planet completely. The fact that your orbital ring is attached to Earth simply means that if it moves relative to Earth, it'll break the tether and cause problems. The best way to avoid these problems is to put the ring in a circular orbit over the equator at geosynchronous height moving in the same direction that Earth spins- in other words, a geostationary orbit, which you've already done. The formula for Newtonian gravitational acceleration is $$ a\_g = {GM \over r^2} $$ Plugging in Earth's mass and the radius of geostationary orbit, we get $$ a\_g = {\left(6.674 \times 10^{-11} {N m^2 \over kg^2} \right) \times \left( 5.972 \times 10^{24} kg \right) \over \left(42164000 m\right)^2} = 0.224 {m \over s^2}$$ So people on the ring will experience about 0.02 gees of acceleration from Earth's gravity (1 gee = 9.8 m/s^2), but the ring itself (being in freefall) will be accelerating in exactly the same way. As such, people on the ring will feel weightless- they'll float around in it, just like astronauts on the ISS (or any other spacecraft in orbit). Now that I've said that, I will note that you've specifically characterized this space station as a "ring". This suggests that you'll be spinning it for artificial gravity. Just to get you started, the formula for centripetal acceleration is $$ a\_c = {v^2 \over r} = {v \over t} = {r \omega \over t} $$ where $a\_c$ = centripetal acceleration (i.e. the "gravity" that people standing on the inside rim of the ring will feel), $r$ is the radius of the ring, $v$ is the linear speed of the edge of the ring, $\omega$ is the angular speed of the ring (in radians per second), and $t$ is the period of the ring's rotation (i.e. the time it takes to make one full revolution). You want $a\_c$ to be equal to one gee (9.8 meters per second squared); if you know how big you want the ring to be, this will tell you how fast it should spin. Also, if you spin the ring, you'll probably want it to be in the same plane as Earth's equator. A spinning ring is like a top or a gyroscope- its axis of rotation will want to point in the same direction all the time. If you mount the ring perpendicular to the tether, spin it up, and wait six hours, you'll find that the Earth (and the tether) will have rotated under it, while the ring itself has not. To keep it from crashing into the tether, you'd need to transfer all of its angular momentum somewhere else (no easy task, but doable if you have two identical rings stacked on top of each other, spinning in opposite directions- if the structure connecting them is sufficiently rigid, their angular momenta cancel out, and you can spin the whole assembly any way you want), or abandon the wheel-on-a-stick visual and mount the ring in the same plane as the tether and the Equator, like a unicycle. Finally, the whole assembly will not have any noticeable effect on the Earth's orbit unless it's a significant fraction of the mass of the Moon- and the Moon is much bigger than most asteroids. Getting something that big into orbit will not be at all feasible any time in the foreseeable future, whether it's lifted up from Earth or dragged down from interplanetary space. Edit: I should clarify that the above paragraphs were written under the assumption that your "orbital ring" was nothing more than a ring-shaped space station with some space elevators attached. The sort of thing that we could plausibly build once we figure out space elevators. However, I've been informed that this may not be the case, and that instead you may be going for a megastructure of mind-boggling scale, encircling the entire planet at geostationary altitude. In the case of a megastructure at geosynchronous altitude spinning in time with the Earth, the answer is quite simple: The ring is in freefall, and therefore anything inside will float around like in any normal-sized space station without artificial gravity. However, if you push the ring outward (by lengthening the tethers) without changing its angular speed (i.e. keeping it at 1 revolution per day), you'll start to get centrifugal gravity. Things inside the ring will "fall" toward its outside edge. We can compute how large the ring needs to be in order to get one gee of artificial gravity this way. Here's the basic equation: $$ a\_c = a\_g + g $$ where $a\_c$ is the centripetal acceleration at the ring's edge, $a\_g$ is the acceleration due to Earth's gravity at the altitude of the ring, and $g$ i our goal: standard Earth surface gravity, 9.8 m/s^2. The centripetal acceleration is the acceleration required to put an object on a circular path. Part of that, for a person standing on the ring in in our scenario, will be supplied by Earth's gravity, and the rest by the outside rim of the ring. Its that "the rest" bit that we want to be one gee. Looked at another way (specifically, from a frame of reference spinning at the same rate as Earth), $a\_c$ is the centrifugal acceleration pushing the ring's occupants outward, $a\_g$ is the gravitational acceleration pulling them inward, and once again, the difference is what they'll actually feel. So, plugging in the formulae for $a\_c$ and $a\_g$: $$ {r \omega \over t} = {GM \over r^2} + g $$ Rearranging things a bit, trying to solve for r: $$ {r^3 \omega \over t} = GM + gr^2 $$ $$ {r^3 \omega \over t} - gr^2 - GM = 0 $$ Aaaand that's a cubic equation that I don't know how to solve. Wolfram\|Alpha gives [a fantastically complicated solution](https://www.wolframalpha.com/input/?i=solve%20for%20r%3A%20r%5E3%20%20w%20%2F%20t%20-%20g%20%20r%5E2%20-%20G%20%20M%20%3D%200) for r, as well as a couple of equally-complicated solutions with imaginary numbers that can safely be ignored. So I'll just let WolframAlpha puzzle through the numbers on its own... and [the solution](https://www.wolframalpha.com/input/?i=r%5E3%20%20w%20%2F%20t%20-%20g%20%20r%5E2%20-%20GM%20%3D%200%20where%20w%20%3D%207.3%C3%9710%5E-5%2C%20t%20%3D%2086400%2C%20g%20%3D%209.8%2C%20G%20%3D%206.674%C3%9710%5E-11%2C%20M%20%3D%205.972%C3%9710%5E24) turns out to be r≈1.15989×10^10 meters. That's about 17 times the radius of the Sun, 30 times farther out than the Moon, and 375 times the radius of geostationary orbits. Good luck building that! [Answer] There would be some 'gravity' on board the station, but it would actually be in the opposite direction - away from Earth. This is because a station attached to a rotating body (Earth) by a space elevator would have to be at a distance somewhat beyond that of a geostationary orbit. The stations are being held in place by the space elevators; and if the elevators were to snap, the stations would, I believe, zoom off into an elongated elliptical orbit. Since you have one solid structure, a ring, orbiting earth, it wouldn't zoom off. Rather, it would act like a centrifuge space station... a centrifuge space station 85,000 km in diameter. The equation for determining the acceleration you get from a centrifuge is: $ a = R(\frac{2\pi}{T})^2, $ where 'a' is the acceleration, R is the radius, and T is the rotation period. At geostationary orbit, a ring station with a rotational period exactly equal to Earth's day period will find that its acceleration outward is exactly equal to the pull of Earth's gravity down, so there will be no net pull up or down. If the rotation period is constant, however (which it would be, since it's tethered to Earth by the space elevators), then increasing the orbital radius would increase the 'gravity' pulling outward, away from Earth. This is a linear relationship, so doubling the radius doubles the outward gravity. If you went and made the ring station 170,000 km in diameter, you'd have an outward gravity of about 0.45 meters per second squared, while the downward gravity would be about 0.05 meters per second squared, for a net outward gravity of about 0.4 meters per second squared, about one twenty-fourth of what you get on Earth. So, unless you wanted to make the ring absurdly huge (like, ten times the distance from the Earth to the moon huge), getting rotational gravity from a ring station tethered to Earth isn't really feasible. If you were closer than standard geostationary orbital distance to Earth, you would get downward gravity from Earth... but then the station would need to be a rigid body, holding itself up against Earth's gravity; which is, as far as we know, impossible from an engineering standpoint on account of the sheer size and mass of the station. So, long story short: The station is effectively in free-fall orbit, and while there might be some outward pull, depending on how far past geostationary orbital distance the station is, it won't be very much. [Answer] It's microgravity (free-fall) First I would like to clarify that geosynchronous orbit and geostationary orbit are not quite the same thing, and that considering the ring is tethered by space elevators you must mean geostationary. The difference is that geostationary is a specific geosynchronous orbit that sits on the equator and rotates at a rate equal to the Earth so that any point on the orbit is always directly (or nearly) above the same point on the ground, which is necessary for a tethered space station of any kind. The only alternative would require some sort of force continuously adjusting the station's acceleration to avoid it falling to Earth. That said, anything in geostationary orbit will have basically negligible gravity. There is of course gravity, but it is just enough to keep the station in place, without pulling it downward. As massive (pun intended) as a ring structure around the Earth might be, I don't imagine it could be built large enough to actually have a strong affect on gravity, or you would end up having to adjust all the equations about the force of gravity anywhere on the planet. [Answer] As Chronocidal observed, solid rings don't orbit well... they're intrinsically unstable, and likely to crash (because as soon as they get off-centre, the nearest bit gets pulled harder by gravity and the further bit less hard and it'll accelerate towards the planet). You could fix this if your space elevators were orbital towers, but making compression members 36000km long sounds like an even harder engineering challenge than making space elevators which are already pretty crazy hard. Possibly the counterweights on your elevators can provide a correcting outward force without the need for compression members, but as your ring won't be unbendably stiff (it'll be a quarter of a million km in circumference, and good luck making something that size really stiff!) you'll need a hell of a lot of space elevators to hold it still. Bicycle wheel earth! What you could use instead is a [Dynamic Orbital Ring](https://en.wikipedia.org/wiki/Orbital_ring). These use much shorter tethers than space elevators (maybe a mere 1000km tall, and a ring circumference of 46000km... child's play if you can make a space elevator!), and maintain their position by being spun so it isn't in orbit and isn't held up by towers, but held down by the tethers. They can also be placed in various orientations and altitudes, unlike your geostationary ring which could only be built in one orbit. You build stuff on the tethers and supported by the ring, but you don't attach anything to the spinning ring itself because its sole purpose is to hold everything else up. Gravity on a ring of this type is indeed computed in the same way as you'd compute force due to gravity under normal circumstances. Thus, at 1000km altitude on one of these rings you'd experience about 75% of Earth's gravity, for example. You could build a dynamic ring of this type at geostationary altitude if you really wanted and had access to materials of implausible strength, but I'm not really sure why you'd want to. [Answer] From the question and some of the answers I read there seems to bit of a misunderstanding of the subject at hand. I will try to clarify. An Orbital Ring (OR from now on) is NOT some kind of giant ring that somehow occupy an entire orbit around a planet. Such a structure would be orbitally unstable and would require active correction to maintain it's position, it would also be impossible to build without exotic materials. An OR is a massive active structure that is composed mainly by a large set of co-orbital objects (we'll call them the core). OR are powered by electricity and require no loss of material to be maintained (no remass needed). More refined versions of the concept have the entire orbit surrounded by a (magnetically suspended) shield, and more facilities can be built on top of the shield. The shield can protect the core from things like an atmosphere, meaning your OR can, in theory, be in an orbit with a lower point just a few meters above ground. An OR can be built with modern technology (although it would be a massive project, 1000s of times more expensive than anything ever built). In some versions, long cable sometimes hung from the OR down to the surface of the planet; usually to ease material transport from and to the OR. These cables are usually just a few hundreds Km long and aren't true space elevators in the sense that they aren't supported by gravitational nor centrifugal forces and require no counterwheight like normal space elevators; for all purposes they are just a cable hanging from a very tall structure. In theory you can build an OR at any orbit, however building one at GEO would make little sense. OR are usually built to easy access to space, you can lift material to the ring above the atmosphere and then magnetically accelerate the material up to any orbit you desire. If you build your OR at GEO then might as well build a normal space elevator instead. The gravity. Here's the thing: the only part of the OR that is actually "in orbit" is the core, the rest (the shield, the cables, the city, whatever...) is not in orbit at all; it's just standing there sitting on top of the shield. If you have an OR at GEO then the gravitational attraction will be toward the Earth and have a value of about 0.23 m/s2 (less than the Moon). At a much lower orbit the gravity will be just a bit less that the surface gravity of the Earth. [Answer] Start with a simple beanstalk made out of carbon nanotubes or better. A specific strength of 100 or more -- that is MPa / (kg/m^3). Park an artificial asteroid in geosynchronous orbit. Spin a cable of this stuff down towards the Earth (with a small weight on the end), and another outwards (with a much heavier weight on its end). Attach to ground. Solve all of the instability problems. Repeat a dozen or more times. Each of these have a "station" at geosynchronous orbit (what is left of the artificial asteroid), a cable going down to Earth, and a tail going out. To launch something to space, you send it out the tail then drop it (this causes the cable to whip some, so there are limits to how much you can use it this way). At the geosynchronous station, spin and Earth gravity are equal. At the tail-station, there is going to be more spin gravity than Earth gravity. Below the geosynchronous station, there is going to be more Earth gravity than spin-gravity. Now, do something crazy. Spin a fiber from one beanstalk to another and hook them up with carbon nanotubes. Repeat until you have a ring. These carbon nanotubes are theoretically zero stress, but the entire orbit is not stable. You can, however, wheel in or out the tails to fix instability without ejecting mass, and transport force over the ring of nanotubes, and it is plausible that you could make that entire thing dynamically stable. Along the nanotube ring, there is going be zero net gravity -- Earth and Spin gravity add to 0. The ring will be 35,786 km above the Earth, or just over 40,000 km above the center of the Earth. This makes it about 1/4 of a million km long, or about 7 times as far around as the Earth is. Suppose we take that ring, and we detach it from the beanstalks. Then we spin it up. f = m v^2/r -- to hit 10 m/s^2 we need v^2/40,000 km = 10 m/s^2, or v^2 = 400,000,000 m^2/s^2, or v = 20000 m/s; roughly 6 times geosynchronous orbital speed. At that speed, things attached to the ring will experience roughly 1 gravity. For every m^2 of cross section the ring has 1/4 million km \* m^2 \* 1300 kg/m^3 = 3 \* 10^14 kg of weight. This is also under the effects of 1 gravity; so the carbon nanotubes have to support that weight. Carbon nanotubes can handle 130,000 MPa in tension, or 1.3 \*10^11 N per m^3. The ring is under 10^15 N of tension, so the tubes can hold less than 1/20,000th of the ring's length without support. In theory you could relieve tension at beanstalks, but 20,000+ beanstalks seems like a bit much. Even at 1/3 G you'd still need 6000 beanstalks. Now, you could reduce the height of the ring; it is spinning and supported by beanstalks, so it isn't really in orbit at this point. At 1/3 the height you get 1/3 of the mass, together with 1/3 G ... still requires 2000 beanstalks. In short, spin-gravity around an entire planet is a large step beyond building a beanstalk. On the other hand, theoretical materials that are ridiculously stronger than carbon nanotubes could be used. But barring that, there will be no spin gravity of any kind. [Answer] The people in the Ring would, essentially, be in zero G. Being attached to the Earth by elevators would have no effect on this. Gravity is a warping of space/time around a mass. It is not transmitted like heat but is a warping of the universe. If the ring is in a geostationary orbit (being far enough out to rotate just fast enough to keep up with the ground) then they are in free fall on the ring. Now, if the ring is lower or higher it would need to continually thrust to maintain position. That would add a sideways force that would behave as gravity. The mass of the ring wouldn't really cause gravity unless it was massive enough to cause problems for Earth. Even then the gravity would only really be felt on or near its surface. [Answer] An orbital ring is 2 separate rings. The inner ring spins faster than orbital velocity producing a centrifugal force that magnetically pushes the outer large ring away from Earth's gravity. The larger outer ring is pushed in the opposite direction so that it appears to be in a geostationary orbit relative to Earth's rotation, although the slower larger outer ring is not in free fall since it spins too slowly to maintain an orbit. The inner faster ring supports its weight with centrifugal force. Notice I said weight not mass. The outer ring would have gravity. Slightly less than earth surface gravity but enough to walk normally. It'll still need an enclosure to hold an atmosphere. The whole point of an orbital ring is to lift stuff into orbit and it needs to be rigid to do that. An unpowered ring in a free fall orbit around Earth could be made of cheese string or tungsten and it would sag like a wet noodle as soon as you put a force on it, just due to its length to width ratio. It's the inner spinning ring that does all the work making it useful. Fun fact: Orbital rings around Jupiter can have 1G if far enough away taking advantage of the inverse square law. Around our Sun being close enough for that would roast us, but around a small red dwarf star is well within the capabilities of many materials. ]
[Question] [ It's a bit more complicated. I'm creating a sci-fi world for a tabletop game. One of my created races is a form of humanoid octupi. My idea is for there to be a nuclear war that forces their species out of their aquatic habitat. But I want to figure out a solution that still allows for a workable habitat on the surface. Honestly I am probably thinking too far into this as the world I'm creating is on a galactic scale. But if anyone has any solutions, they would be greatly appreciated! [Answer] Not possible. You land dwellers need the ocean to survive. Don't forget that the oceans are part of the water cycle. If they are so messed up from radiation that no life can thrive in them, then the water vapour will be extremely radioactive too. Everything will die in areas where it rains. Also don't forget that [water is actually one of the most convenient materials for radiation shielding](https://what-if.xkcd.com/29/). In order to mess up with the oceans at large you would have to use such an amount of nukes that the surface would be scorched. If you drop the full power of the Tsar Bomba on land, you can potentially devastate a very large area: ![Oh the humanity](https://i.stack.imgur.com/q6tYf.jpg) [Do the same at the bottom of the ocean](https://what-if.xkcd.com/15/), and unless you've got a strong tropical storm going over it, you won't get much destruction done. The blast bubble will not be much larger than one kilometer across at most, and it will not make it to the surface. Radiation will spread but again, water is a very good shield - and there is lots and lots and lots of ocean to take that. [Answer] Perhaps the nuclear aspect of the war ended up being more tactical rather than strategic. The people in charge knew how bad it would get for their side if the use of nuclear weapons escalated too much. So they stuck to mostly pin-point low-yield nuclear attacks on key military and political sites. Conventional weapons gave more bang-for-your buck against infantry and tanks on the battlefield and posed less threat of fallout harming friendly forces, and wiping out cities would lead to retaliation in kind. The open ocean, however, was another story. The ocean is big, and friendly forces were far away, making indiscriminate use of nuclear weapons less of a problem. Nobody knew exactly where the submarines were, leading to widespread use of nuclear depth charges and nuclear torpedoes both for offense and defense. Aircraft carrier groups were heavily armored, highly defended against anti-ship missiles, and spread over wide geographic areas, making strategic nuclear strikes the most effective solution. Lots of undersea fiber optic lines necessary to effective communication had been hidden, making nuclear explosions the most reliable way to interfere with enemy communications. It seemed much safer to knock out the enemies' satellites using high-altitude nuclear explosions over open ocean than over land. Etc., etc. Further, the ocean was really the key site for the war. If we are talking about different superpowers on different continents with roughly equal military capacity, travel by ocean is the only way to effectively move large forces. The most effective way to beat forces coming from another continent is to kill them before they can land. So the bulk of the war ended up taking place at sea. Basically, the issues around nuclear escalation and mutually-assured destruction that led forces to limit their use of nuclear weapons on land, especially around major population centers, didn't seem to apply to the ocean, leading to people being much less careful there. [Answer] Fallout ravaged the surface — but the surface had survivors, people who saw the end coming and built bunkers and shelters that preserved precious anarobic bacteria along with seeds and starts. It's taking a while, and bandits keep trying to steal the goods, but the land is recovering. But nobody thought to preserve the sea.... And when the fallout fell over the sea it killed the fish and the whales and the seaweed and the starfish... and the plankton. And all the rest of the microbiotic sea life. It collapsed, forcing your octohumans to the surface just to find air to breathe.... And because nobody thought to save plankton and other microbes for the sea, the sea is going to stay dead until the land gives up her bounty to allow the death-and-rebirth cycle to begin again in the sea. And now it's a race, a race to build enough biomash to drop into small, isolatable seas to help kickstart the process. It would free the planet for new growth... new civilization... and everybody wants that but the bandits, who want to stay in control by fear. [Answer] If these intelligent octopi already exist, then you really don't need much to explain why the octopi might leave the water. Real ones already do this to grab food on land over short distances. Intelligent ones might do the same - just venturing further onto land. They now realize humans are gone, and the remains of human civilization (tools, materials, knowledge) are there for the taking. If you are looking for longer term evolution, this could be what gets them out of the water at first, and then they evolve to be land dwelling creatures. [Answer] In a nuclear war, the bombs will target strategic cities and military points. Almost all of them are on land. If the oceans become uninhabitable because of a nuclear war, definitely the land will be worse. However, you could (hypothetically speaking) take, as an alternative, a biological war (not nuclear). That event could deploy microorganisms over the land able to exterminate humankind. The microorganisms could mutate into the ocean and perform a "forced evolution", changing the marine ecosystem and making your octopi explore the land as a better alternative to live. [Answer] Nukes are not the way to go, if you do that much damage to the aquatic ecosystem you'll wipe out everything that uses oxygen. What you need is some kind of mid foodchain dieback that forces your cephalopods to seek nutrient sources ashore. It's about wiping out their immediate prey without destroying the primary, photosynthetic, produces. Weirdly enough we're actually doing a pretty good job of this at the moment with our fishing practices. If you force deepsea cephalopods in close to shore they'll be exposed to more wastes washing off the continents, this will include more radiation and will increase their rate of mutation and death, increasing evolutionary pressure on them and forcing either changes or extinction. There are different ways this could happen in a Sci-fi setting, land dwellers over harvesting the deeps is one, the other that immediately comes to mind is a targeted pathogen designed to kill fish off. [Answer] Does not seem probable <https://www.quora.com/Does-water-block-radiation> There is a reason water is used in nuclear reactors except for cooling. It blocks radiation exceptionally well. So actually, it seems the opposite. The most penetrating kind of radiation, gamma radiation is halved every 15 centimeters of water it passes through. That means after 1 meter of water only 1 percent of radiation is left, after 3 meters less than 1 part per million. On land you need lots of lead to block gamma radiation and the lead in itself is both a poisonous heavy metal and heavy as hell. --- More realistic would be a story of a human nation building cities some 100 meters under sea level and use it to survive an all out nuclear war that totally destroys the surface of the planet. Like an Atlantis of the future or something. [Answer] You're better off with a chemical war rather than a nuclear war. If you had a highly water soluble, very long life, and extremely toxic agent, you could conceivably make this work. The land is rendered safe after some time as the water cycle flushes all of the toxins to the sea. Think salt, basically - our seas are uninhabitable to a species that is not salt tolerant, but freshwater is fine. Except in this case rather than large amounts of salt accumulating over a long time, a comparatively small (but still large) amount of toxin is released in the war. You can justify the amount of toxin by saying that large doses are required to kill quickly (i.e. to be useful for a hot war) but that it turned out even extremely small doses turned out to be devastating if exposed over a longer duration. ]
[Question] [ Yesterday I was reading through [this question](https://worldbuilding.stackexchange.com/questions/49272/how-to-build-a-1-gj-railgun-proof-tank) and it got me thinking: would it be possible on a ship or building mounted railgun to convert the energy from the recoil of the shot in order to partially recharge its capacitors for the next shot? [Answer] # No, you cannot ...or rather: you should not be able to do it. This is because if — after the shot — you have a significant amount of energy in the recoiling mass, then you have wasted energy that did not go into the shot. But this is moot because your gun was attached to something really heavy, in your case a ship, or a building. This means there is no recoil energy worth speaking of. Physics that explains why to follow... ## [Conservation of momentum](https://en.wikipedia.org/wiki/Momentum#Conservation) Momentum is mass times velocity. $p = m\times v$ Double the speed of an object, and you double the momentum. Halve the mass of an object, and you halve its momentum. And conversely: for any given momentum, if double the velocity, you halve the mass, and vice versa. [Recoil](https://en.wikipedia.org/wiki/Recoil) is a consequence of [Newton's Third Law of Motion](https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion#Newton.27s_3rd_Law). In this context it means that whatever momentum you have imparted on the projectile, will also be imparted on the gun and whatever it is attached to, but in the opposite direction. This means that in your scenario, immediately after the shot, the following applies: $m\_{shot} \times v\_{shot} = m\_{ship} \times -v\_{ship}$ Since the ship is many times heavier than the shot, it means the recoil speed of the ship is the equal amount of times smaller compared to the projectile speed. Say the projectile weighs 10 kg and the ship weighs about 50 000 000 kg ([the heaviest battle ship in WWII](https://en.wikipedia.org/wiki/Japanese_battleship_Yamato) weighed 72 800 tonnes, or 72 800 000 kg). That means that the recoil speed of the ship will be 5 million times smaller than the muzzle speed of the shot. So let us say [this railgun lobs out a 10 kg shot at 2 500 meters per second](https://en.wikipedia.org/wiki/Railgun#U.S._Navy_tests). This means the recoil velocity on the ship will be $0.5 mm/s$ (1/50 inch per second). Using $E = \frac{mv^2}{2}$ to calculate the inertia of the ship, we find that the energy available for you to recover is... drumroll ...$6.25 J$, or 0.0015 kcal. This is less than the energy required for you to stand up from a sitting position. The corresponding energy in the projectile is 31 250 000 Joule. Those 6.25 Joule recoil energy are meaningless is comparison. The astute will notice that the ratio between these energies is the same as between the masses. In case your railgun is sitting on a building, then the mass of the gun and its fixture is even higher (especially if you count the Earth itself as part of the fixture) and then the mass becomes so ridiculously large compared to the projectile that the recoil energy is so near nothing it becomes entirely irrelevant. So in conclusion: no, there is no energy for you to recover. And that is good, because as much energy as possible should go into the shot. Putting energy into the recoil instead, and then trying to recover that — with the inescapable losses of energy that will follow — and then putting that into the next shot, would be nothing but a huge waste. [Answer] You can definitely recover kinetic energy using some sort of system, like a kinetic energy recovery system (aka KERS) used on some racecars when braking. That's called [regenerative braking](https://en.wikipedia.org/wiki/Regenerative_brake) (thanks to @JohnDallman for the tip). If you have a racecar, you can store that recovered energy into a [flywheel](https://en.wikipedia.org/wiki/Flywheel) or a [supercapacitor](https://en.wikipedia.org/wiki/Supercapacitor) to reuse it later. If you're driving a Prius, it's most likely used to charge back to the battery a tad. Some cars can also recover energy on a down slope. However, since we live in an imperfect world, you will only recover a fraction of the energy used to fire a shot. Firstly because some of that energy went into the projectile. Secondly because there's always waste, typically in the form of heat. Thirdly because converting one form of energy into another one (here kinetic to kinetic to electric) isn't 100% efficient either. tl;dr: You can recover some of the energy, but you can most definitely not recover it all. [Answer] Using [Michael Karnerfors' answer](https://worldbuilding.stackexchange.com/a/49443/19951) as a basis for the numbers, only instead of directly attaching the rail-gun to the ship so that everything moves as a whole, attaching the gun to a flywheel (or something similar), which is then connected to the ship so that only the gun moves (and the flywheel rotates) so that KERS can be used as in [AmiralPatate's answer](https://worldbuilding.stackexchange.com/a/49441/19951) allows for the kinetic energy of the gun to be recovered: Note: This answer takes the rail-gun to be intrinsically 'not the ship', so that the gun will move regardless of how it is attached. While it could also be completely built in to the ship (or built into the ground) so that it cannot turn/move independently of whatever it's on, in which case [Michael Karnerfors' answer](https://worldbuilding.stackexchange.com/a/49443/19951) applies completely, we like our guns to be able to do things like turn and maybe even move independently of whatever it's placed on. Taking the mass of the rail-gun to be $~1.5\times 10^5kg$ as in [here](https://en.wikipedia.org/wiki/BL_18_inch_Mk_I_naval_gun), gives the speed of the railgun immediately after firing as $v = \frac{2.5\times 10^4}{1.5\times 10^5} = \frac{1}{6}m s^{-1}$, which gives a kinetic energy of $$KE = \frac{1}{2}\times 1.5\times 10^5\times \frac{1}{36} = \frac{6250}{3}J$$ At this point, there are two options: either the gun can be directly attached to the ship without any recoil and whichever method used of attaching it needs to withstand the large stresses that this creates or some recoil system can be used to help prevent these stresses. Using the recoil option allows for KERS as well as decreasing these stresses, which decreases damage done to the ship/the mechanism that attaches the gun to the ship. Otherwise, the resulting reaction force that exists as a result of the projectile leaving the gun will cause a torque that results in a stress on the mechanism that attaches the gun to the ship. Using something that decreases this force (something that dissipates recoil) decreases this stress and so decreases the damage done to this mechanism. To forestall the argument about needing to put as much energy into the projectile as possible, I'll point out now that the momentum and energy of the projectile are already well defined and the mass of the overall system or how the gun recoils doesn't change this. It does increase the amount of energy needed to be put in the system in the first place, but we want the gun to move around a bit, so it'll have to have some recoil in this case anyway (as well as for the above reasons). In any case, the energy required to fire said projectile is $3.125\times 10^7J$, about 4 orders of magnitude greater than the recoil of the gun, so, while KERS can be used in principle, in practice, there is no real point. Decreasing the mass of the gun is pointless as more energy is needed overall. However, there are large amounts of excess heat generated and large amounts of electricity used in a rail-gun, so there may be other ways of regenerating some of the used energy. Having said that, rail-guns that have been created so far have a tendency to get heavily damaged, so allowing the guns to move might decrease the amount of damage caused to the guns. ## In summary: It is possible to use energy from the recoil to partially charge the capacitors, but in practice, you're recovering less than 0.1% of the energy required to fire the next shot, so there's no real point unless it decreases damage done to the gun [Answer] Don't forget that the principle of the machine gun is to use energy from the recoil to move another round into the barrel. I imagine that future weapon designers will have that concept in mind as well. [Answer] It's possible, as other answers indicate, to convert kinetic force into electricity, so I won't repeat that. But what you should think about is the cost-benefit ratio. The truth is, it's not feasible to add the complexity of an extra subsystem to an already ridiculously complex system. Think of the amount of electricity it takes to accelerate anything to several times the speed of sound. Power savings from a kinetic converter would simply be insignificant. [Answer] you don't have to harvest the KE. the heat generated by rail guns is substantial. simply add peltier panels or use liquid cooling diverted to a sterling engine to harvest 30% of the waste heat. apparently because railguns can accelerate things to 3 km/s, the heat from friction of both the amount of electricity flowing through coils and the friction of the projectile is substantial. [Answer] I also read the question you're quoting. Well after reading it, I think that yes, you could generate some energy from recoil, however, not much. It's quite easy to guess you can produce energy with it, just like our cars generates energy for the battery while we drive, or just like automatic/semi-automatic weapons use the movement when firing to load and fire another bullet. The difference with such gun, is that the recoil it generates can't be compared with a rifle's recoil, or a wheel movement. As stated in that answer, to allow a 1 GJ tank with a small size in regard to a cannon like the German super heavy artillery, most of the recoil energy must be redirected somewhere. Some would be absorbed by the hull, some could be redirected into the ground, and some would be redirected in shock absorbers. You might say "Then manage to make everything go into that shock absorber ?" Well we can do that, provided it can resist the recoil. Then we'll need to convert the recoil energy and here lies a problem, we can't convert 100% of that energy. The main problem is : you don't want what you use to convert recoil into energy to tear apart, destroyed by that energy, so you'll need to soften the recoil, or to spread the energy between multiple converters, losing energy in the process each time. If you had a continuous flow of energy, totalling 1GJ, converting it wouldn't be a problem, no, but converting at a time T a huge amount of energy is clearly harder. Of course, on top of that problem, remember that a mechanical converter can't convert 100% of what it receives. As I imagine that gun, I think its shock absorbers could work somehow like pistons activating alternators, and that would imply a loss of energy at each movement. Other kind of converters doesn't seem to me better suited for this, using the heat from that gun could work but wouldn't generate a lot of energy, same thing would apply to radiation or to the blast of the canon itself. So perhaps you could use the energy from that gun to supply some systems like computers for a while, but it would most likely be negligible compared to what you need to fire with that beast. ]
[Question] [ Santa delivers to the homes of the 7 billion people on Christmas night, eating cookies and milk at each of the homes. Provided each home puts out a glass of milk and 3+ cookies, that's a lot of milk and cookies. How does Santa avoid having heart attacks from bad cholesterol caused by all the cookies and milk? [Answer] If Santa ate all that, he'd be packing on the pounds way more than he already is (and Santa is not a lightweight now). Since nobody's reported a 2-ton Santa, there must be another explanation. Santa's metabolism is really, really souped up. This makes sense; even though he's not doing the hard job of flying the sled at supersonic speeds, he's zipping up and down chimneys at a high rate of speed, hauling a substantial sack of toys (and coal) with him on each trip. Between the exercise and his supernatural metabolism, the milk and cookies never had a chance to do him much harm. Also, have you heard the horrifying news? In some parts of the world health-minded people have been putting out skim milk and sugar-free cookies, and there's a trend in California to replace it all with water and carrot sticks. Santa [hates that](https://worldbuilding.stackexchange.com/a/32024/28), but he still gets enough good stuff that he hasn't responded with truckloads of coal. Alternatively: we only know that the milk and cookies disappear; you assume that Santa is eating them on the spot, but you don't actually know that. He's got a whole gang of elves who have burned the midnight oil to prepare him for his big night. The least he could do (since he's probably not handing out Christmas bonuses) is to bring back some cookies! And maybe he even carries a jug of holding in his sack of holding, to collect milk he doesn't drink on the spot. (Also, probably not 7 billion people, but after the first billion the dietary impact doesn't make that much of a difference.) [Answer] Santa does not have an ordinary sleigh, he has a "Mr. Fusion" and a flux capacitor build into it. Instead of eating all cookie and drinking the milk, he uses it as fuel for the "Mr. Fusion". Using this advanced technology it is no problem to deliver all presents in one night. After all Santa can go back in time with his sleigh. It is rumored he might also had a car and a train with similar technology. According to eyewitnesses he also used to be much skinnier when he started the business. A super secret photo below: [![(Attribution: JMortonPhoto.com & OtoGodfrey.com)](https://i.stack.imgur.com/XXg76.jpg)](https://i.stack.imgur.com/XXg76.jpg) (Attribution: JMortonPhoto.com & OtoGodfrey.com) [Answer] The origin of contemporary mass culture Santa is the Saint Nicholas of Myra who died in the IV century so I would assume that simply Santa is already dead and count his appearance during X-mass rather as miracle than physical presence. And I don't believe a few (√ó10‚Åø) cookies could do any harm to a saint during supernatural apparition. [Answer] Per the latest research, dietary cholesterol intake has little long-term effect on blood cholesterol levels. Blood cholesterol levels seem to be determined more by genetic factors and overall level of physical fitness. <https://www.ncbi.nlm.nih.gov/pubmed/16596800> So the answer is that he's got good genes (he must to have been alive this long) and that the fat is actually for insulation to keep him warm. He's in pretty good shape underneath it from schlepping hundreds of tons of gifts around. [Answer] The only solution to the "Santa problem" I've ever seen that wasn't just "magic" right from the beginning is parallel Santas. There are actually millions of Santas that run out and deliver the presents in parallel. In this case, the cookie problem is resolved just as well as the travel problem. Each Santa has to eat a couple hundred cookies or so. They might not feel so good the day after, but it's at least within the realm of possibility. [Answer] How does Santa do everything else, like flying reindeer, and keeping tabs on the moral fortitude of everyone on earth? *magic* That, or he has an extreme metabolism that requires him to maintain an obese physique to live, but that's kind of depressing to apply to Santa. [Answer] The inside of Santa opens to a pocket dimension and whatever he eats simply goes there, adding mass to his parallel "self". The mass in the pocket dimension keeps growning and growning but even a few tens of thousands of tons extra a year doesn't change things all that much. For example, Santa's belly in the pocket dimension doesn't even have its own moon and it's many, many more (Earth-) years before the belly has any hope of starting fusion. Santa in our dimension is just a convenient shell around the pocket dimension and eating the cookies and milk doesn't really add to his - already considerble - weight. [Answer] Cholesterol doesn't affect Santa, because Santa doesn't eat them. In fact, that isn't Santa. Santa died long ago. Fearing the effect this would have on the world, the elves created a Golem to take his place. Unfortunately, Santa's elves only had experience in making shoes, toys, and cookies. With the best intentions, they created an unnatural creature using Santa's body and the latest in cookie technology. This body is inherently unstable, and also gets bitten by the reindeer a lot. The body must feed to replenish its mass. This is done through the ritual sacrifice of milk and cookies, a ritual whose meaning has been cleverly disguised as "snacks." Without Santa's leadership, the North Pole has been struggling to keep with the latest technology. This can be seen by their inability to upgrade "Santa's Sleigh" to something more useful like a helicopter, and NORAD's ability to track "Santa." The lack of Santa's oversight has also hindered the present selection. This is why you may receive presents you did not want. [Answer] Santa doesn't actually eat the milk and cookies. The true solution is top secret and not to be shared: > > Instead, your parents or other people in your household do so. You can test this by living alone and leaving out milk and cookies. They'll still be there the next morning. So it's whomever actually eats the cookies that experiences any negative effects on their health. Fortunately, these are distributed across a large number of people. > > > Santa just drops off presents. Or coal. As appropriate. [Answer] Santa is not human and doesn't have a Liver No liver means Santa can't produce enough cholesterol to survive so he has to get it from the food he eats Santa also has an absurdly fast metabolism which means his body is filled with Testosterone which is made with cholesterol on daily basis so Santa is forced to consume disgusting amounts of animal products to survive. [Answer] Santa is half-elf. He's still too young / too magical / too immortal to be at risk of cardiac arrest. [Answer] All these suggestions neglect that Santa lives at the North Pole year round and a human maintaining a healthy diet in that climate will consume 7,000 - 9,000 calories per day. Since a large belly is part of the image Santa has to sell, he would have to consume an even larger caloric intake than that and chocolate chip cookies would definitely help fill some of that staple diet, as would milk and other items left out by Santa (As for the carrots and water mentioned above, my family did that (and apples) but those were for the reindeer, not the big guy). Also not mentioned is possible compensation towards the elves for a job well done. Perhaps excess chocolate chip cookies are given as holiday bonuses to high performing elves? Certainly seems more in character that Santa pays his employees rather than works them as a jolly ol' slave driver... Maybe elves are payed in yummy goodies rather than money like Oompa Loompas and coco beans and North Koreans and Moon Pies (I'm serious about that too... the North Koreans love the Moon Pie and on more than one occasion an influx has threatened to crash their entire economy.). It certainly seems reasonable for a people who believed proper medical dental care was a taboo until the 1960s. Number wise, 7 billion cookies seems a bit excessive. Christianity as a whole only has 2.3 billion followers, 1/3 of the total seven billion. Secondly, the offering is made per household, not per individual person. The number is massive, but 7 billion is a stretch. While the true size of the take is unknown, we must also factor in non-christian households that participate along with Christian sects that do not participate and regional customs that have different gift rules and even differet delivery days (Feast of Saint Nicholas is Dec. 6th and some cultures do the gifts then with the 25th being purely about the Nativity of Jesus). Still other cultures don't do milk or cookies or both... for example, its custom in Great Briton to leave Santa a glass of Brandy rather than milk... which would explain why his nose looks like a cherry by the time he gets state-side. Finally, everyone seems to forget about the true nature of Santa Clause, aka Saint Nicholas, who's patronage includes children and is famous for his secret gift giving. Perhaps, when the elves are paid and the year is stockpiled for, Santa will still have excess cookies... Knowing the man, such a waste of food would be terrible and it could be reasonable that Santa will use some of the Cookie take to give gifts to children who through circumstance would not be able to have a proper Christmas meal. I'm pretty sure the big guy won't mind if some of the people in the west even sent some of those cookies to the needy and cut out the middle man, since by the time he gets to North America, it's reasonable he had his fill for the night. [Answer] First I want to say that 7 billions people doesn't celebrate christmas, it's only about 2 billions. Also I want to say that the cookies and milk aren't per person, they are per family (each normal family has 4 persons). And finally I want to say that in a lot of contries people don't put food or they but others things like chocolate or marzipan. # Respect Santa doesn't eat cookies or drink milk, maybe he do that but he don't consume all the cookies and milk he gets, he only eat like a human, then he throw away the rest of the food so people get happy that Santa "eat" the cookies... # Squirell (Food for winter) Santa doesn't eat the food in one day, he do like the squirells, they store food for the winter. Santa store all the cookies and milk in the bag when he drop the presents for the 364 remainings days of the year. I don't think that milk would rotten, he is the North Pole. # Gift / Food for they minions Santa has a lot of minions (AKA: elves). He store in his bag the cookies (and in a tank the milk?) and when he reach to the North Pole he gift to his minions all the food for their hard work. Even he can feed their minions with only cookies and milk, see my calculations: $$ \frac{2,000,000,000 \text{ Believers}}{4 \text{ Believers/family}} = 500,000,000 \text{ Families}$$ $$ 500,000,000 \text{ Families} \times 3 \text{ Cookies} = 1,500,000,000 \text{ Cookies}$$ $$ 500,000,000 \text{ Families} \times 1 \text{ Glass of milk} = 500,000,000 \text{ Glasses of milk}$$ $$ \frac{500,000,000 \text{ Glasses of milk} \times 200 \text{ ml/glass}}{1,000 \text{ ml/litre}} = 100,000,000 \text{ Litres of milk}$$ $$100,000,000 \text{ Litres of milk} \times 1.032 \text{ kg/l} \times 420 \text{ Calories/litre} = 43,344,000,000 \text{ Cal}$$ $$ \frac{1,500,000,000 \text{ Cookies} \times 8 \text{ gr/cookie}}{100 \text{ gr}} \times 353 \text{ Calories/cookie} = 42,360,000,000 \text{ Cal}$$ $$ 42,360,000,000 \text{ Cal} + 43,344,000,000 \text{ Cal} = 85,704,000,000 \text{ Cal}$$ $$ \frac{85,704,000,000 \text{ Cal}}{365 \text{ days/year}} = 234,805,479.45 \text{ Cal/day}$$ $$ \frac{234,805,479.45 \text{ Cal/day}}{2,000 \text{ Cal/day}} = 117,402.73 \text{ Humans}$$ I don't know the dayly calories that need elves but Santa is capable of feed more that 100.000 humans only with cookies and milk! (And yes, I checked the water values of milk (87%), they won't die of thirst). Also we can calculate the fat value: $$ \frac{\frac{1,500,000,000 \text{ Cookies} \times 8 \text{ gr/cookie}}{100 \text{ gr}} \times 16 \text{ gr/fat}}{1,000 \text{ gr/kg}} = 1,920,000 \text{ kg of fat}$$ $$ \frac{\frac{100,000,000 \text{ Litres of milk} \times 1,032 \text{gr/l}}{100 \text{ gr}} \times 1 \text{ gr/fat}}{1,000 \text{ gr/kg}} = 1,032,000 \text{ kg of fat}$$ $$ \frac{\frac{1,920,000 \text{ kg of fat} + 1,032,000 \text{kg of fat}}{365 \text{ days/year}}}{117.402,73 \text{ Humans}} \times 1,000 \text{ gr/kg} = 68.88 \text{ gr/day of fat}$$ 68.88 gr of fat per day don't kill anyone! They are healthy values! Well, for been exactly for a person who doesn't do physical activities it's bad, but not lethal. And if you want about their cholesterol amount: $$ \frac{\frac{1,500,000,000 \text{ Cookies} \times 8 \text{ gr/cookie}}{100 \text{ gr}} \times 3 \text{ mg/cholesterol}}{1,000,000 \text{ mg/kg}} = 360 \text{ kg of cholesterol}$$ $$ \frac{\frac{100,000,000 \text{ Litres of milk} \times 1,032 \text{ gr/l}}{100 \text{ gr}} \times 5 \text{ mg/cholesterol}}{1,000,000 \text{ mg/kg}} = 5,160 \text{ kg of fat}$$ $$ \frac{\frac{360 \text{ kg of choresterol} + 5,160 \text{ kg of choresterol}}{365 \text{ days/year}}}{117.402,73 \text{ Humans}} \times 1,000,000 \text{ mg/kg}= 128.93 \text{ mg/day of cholesterol}$$ 128.93 mg of cholesterol per day don't kill anyone! They are healthy values! # Biofuel Santa use all the organic matter from food to make biofuel! He lives in the middle of nowhere (North Pole), How he get power? He can use biofuel in generators to produce electricity. Like I said before he gets $85,704,000,000 \text{ Cal}$ in food. $$ \frac{\frac{\frac{85,704,000,000 \text{ Cal} \times 4,184 \text{ Joules}}{365 \text{ days/year}}}{24 \text{hours/day}}}{1,000,000,000 \text{ W/GW}} = 40.93 \text{ GW/h}$$ Enought to power several cities... for an entire year. Well, obviously motors and generators aren't 100% efficients so you can split the number in 2, also I am not sure if cookies can be rotten and turn in fuel... ]
[Question] [ Let's say, hypothetically (perhaps in the setting of a book series), Earth is temporarily destroyed. Antimatter weapons have been used in self-defense during a violent conflict. Now, thousands of years later, humanity has turned to a multitude of alternatives for a home. Venus has been terraformed to have a full 25 hour long day, Mars is once again seeing an (artificial) magnetic field, with the return of oceans and a healthy atmosphere. Not to mention the multitude of O'Neill cylinders have been constructed from the excess resources and energy from using Mercury to construct a Dyson Swarm. However, there's another location that's been neglected. The Moon, aka good ol' Luna. It was a major front during the antimatter echange that brought an end to Earth, and is currently the oldest standing collection of settlements and homes in the Solar System. They get the brilliant idea of adding an atmosphere to the moon, and keeping it there. Let's lay down some assumptions. Humanity has access to 1.5% of the Sun's solar energy output, a planet's worth of elements and mass, as well as water (from Saturn's Ice Moons), excess gasses from the gas giants (Titan is a natural park of sorts) such as methane and nitrogen, and the ability to deploy an artificial magnetosphere to shield Luna. The moon has a daily period of ~70 hours, so it won't freeze at night, and if you have a problem with that then you can take it up with Venus. There would be obvious advantages, especially liquid surface water. There's also the possibility that a lower surface pressure can still be beneficial, as at very low elevations (in deep caves, for example) cities can enjoy lower maintenance and less risk from any breaches in their hulls. But this only goes so far. If the effort needed to introduce and maintain an atmosphere exceeds the benefits provided. Thus, my question: How would humanity "terraform" the moon, i.e. give it a friendly atmosphere? Where a friendly atmosphere would be an Earth mix of gasses with surface pressure within 10% of Earth's. Lasting within tolerance at least a span of 100 Kyears. [Answer] Yes. There are two broad classes of options: 1. A "worldhouse", or paraterraforming. Surround the entire Moon in a spherical dome, or in a collection of domes tiling the surface, to keep the air in. 2. Open-sky terraforming. The Moon cannot retain a breathable atmosphere over geologic time periods... but the timescales for human engineering and lifetimes are much, much lower. If you just keep dumping air onto the Moon, you can indeed build up enough of it to get 1 bar of pressure on the surface. The resulting atmosphere will have a much larger scale height than Earth, and it will continuously leak away into space, but not so fast that you couldn't keep it topped off with regular imports. And if the imports stop, it'll stay remain habitable for a couple million years, so you've plenty of time to fix the problem. [Answer] How much atmosphere do you need, really? A 'friendly' atmosphere with ~20 kPA O2 and overall 90 kPa pressure would be very challenging with Luna's low gravity and her high-insolation orbit. Useful but less friendly atmospheres are less difficult to engineer. 101 kPa: Earth at sea-level 90 kPa: "Friendly" as per OP 50 kPa: "Unfriendly" - air pressure at the [highest permanently inhabited town on Earth](https://en.wikipedia.org/wiki/La_Rinconada,_Peru) 6.3 kPa: "Armstrong Limit" - the lowest pressure at which humans can breath unpressurised 0.6 kPa: "Triple Point of Water" - the lowest pressure at which liquid water can exist in the open For example, aiming for 10 kPa (1/10th of Earth), humans could walk around the surface in casual clothes plus respirators breathing pure oxygen, giving an oxygen partial pressure comparable to high-altitude areas on Earth (drink plenty of fluids!). Simple plants like mosses and lichens could grow on land, and Earth-normal flora in water bodies. At 5 kPa, pressurised respirators and elastic counterpressure clothing would be needed (comparable to scuba gear). Swelling (odema) of the hands and face would be an issue on extended stays outside, but could be relieved by returning to (pressurised) habitats. What gasses to use? According to <https://en.wikipedia.org/wiki/Atmospheric_escape>, Earth's atmospheric erosion at present is "charge exchange escape (~60–90%), Jeans escape (~10–40%), and polar wind escape (~10–15%)". Charge exchange is overwhelmingly just hydrogen and other very light gases. Jean's Escape and Polar Wind Escape are strongly moderated by the gasses' molecular weight and the temperature of the upper atmosphere (exobase). From memory residence time is proportional to the third power of the molecular weight, but I can't locate the reference just now. The temperature of the upper atmosphere might be the most "easily" engineered variable - incoming solar UV heat's Earth's exobase to around 1000K. If your setting's humans filter most of that out somehow, you could keep Luna's exobase to a moderate temperature, and reduce both Jean's Escape and other methods of loss. Buffer Gasses Most of Earth's atmosphere is nitrogen (N2), molecular weight ~32 g/mol, biologically mostly inert. But not useless - it contributes to the overall pressure, and it provides cooling in the event of fire (pure oxygen is a terrifyingly dangerous atmosphere, look up Apollo 1). Your atmosphere needs a buffer gas, and there are many you could choose. If you have a look at the figure on page 4 of [The escape of planetary atmospheres](https://web.archive.org/web/20230220215020/https://geosci.uchicago.edu/%7Ekite/doc/Catling2009.pdf) ([https://web.archive.org/web/20230220215020/https://geosci.uchicago.edu/~kite/doc/Catling2009.pdf](https://web.archive.org/web/20230220215020/https://geosci.uchicago.edu/%7Ekite/doc/Catling2009.pdf)), you will see that Luna could almost hold onto CO2 against Jean's Escape over geological timescales even today. CO2 has a molecular weight of ~44 g/mol, but there are heavier gasses we could use. I will limit my suggestions to those that are non-toxic and non-reactive with common materials, and which provide flame-cooling as good or better than nitrogen. Xenon is ~131 g/mol, and a noble gas. It cannot be photolysed, it doesn't react with anything except under the most extreme conditions, and it is nontoxic. That would do nicely, but it is rare and exotic, and not found usefully concentrated anywhere in the solar system that we know of, other than the atmospheres of Earth, Venus and Mars. Sulphur Hexafluoride (SFl6) is manufactured today in thousands of tonnes per year from readily available precursors. Its molecular weight is ~146 g/mol, even heavier than Xenon. It is nontoxic, very resistant to photolysis, and doesn't spontaneously react with anything much except elemental alkali metals. The drawback of SFl6 is that if something does manage to ionise it (x-rays, extreme UV, a high-voltage electrical arc) the decomposition products are toxic fluro-analogs of phosgene. That will react with water if there is any around and form safer compounds, so this might be manageable if high-energy radiation can be limited on your future Luna (orbiting sunshades tuned to filter UV?). A more fragile but biologically-safer alternative would be octofluoropropane (freon-128). Molecular weight ~188, but breaks down via reactions with UV and water vapor as per <https://www.fluorocarbons.org/environment/climate-change/atmospheric-lifetimes/>. Biologically-Active Gasses Oxygen (O2), CO2 and H2O are the big ones. If you have an open-air biosphere at all, you will have at least 1 kPa of each of O2 and H20, and 0.2 to 1 kPa of CO2. Add another 1 kPa of N2 and/or derivatives such as NO for a sustainable green plant nitrogen cycle. These biologically active gasses will escape over time and need to be replenished due to their low molecular weights (H20; ~18 g/mol, O2: ~32 g/mol, CO2: ~44 g/mol), but the smaller fraction they are of your atmosphere the less problematic this becomes. My 2 Cents Yes, a Lunar atmosphere is definitely possible, but consider reducing expectations (and pressure). Orbiting macro-scale sunshades can help by filtering UV. [Answer] > > Now, thousands of years later, humanity has turned to a multitude of alternatives for a home. Venus has been terraformed to have a full 25 hour long day, Mars is once again seeing an (artificial) magnetic field, with the return of oceans and a healthy atmosphere. Not to mention the multitude of O'Neill cylinders have been constructed from the excess resources and energy from using Mercury to construct a Dyson Swarm. > > > One) it would take an incredible amount of energy to change the rotation period of Venus. It would be much easier to build giant sun shades orbiting Venus. Their orbital period would be such that the Sun facing side on Venus would have alternating light and dark each roughly 12 hours long. The inner sides of those sun shades, facing Venus, would also be reflective. So the Sun shades passing over the dark side of Venus would reflect light down onto the surface, and there would be alternating 12 hour periods of light and dark, just as on the sunward face side. Two) Giving Mars an artificial magnetic field would shield its atmosphere from being knocked off by the solar wind. But atmospheric loss due to solar wind is a rather minor effect compared to atmosphere loss due to the low escape velocity of Mars, 5.027 kilometers per second. According to the discussion on pages 33 to 39 and 54 of Habitable planets for Man, Stephen H. Dole, 1964, an escape velocity of 5.027 kilometers per second would be about 4 times the velocity of atomic oxygen in the escape layer of the exosphere of Mars, and so Mars would lose oxygen at a rate which would reduce the amount to 0.368 of the original amount in a few thousand years. So to keep the oxygen in the Martian atmosphere constant about 62 percent would have be replaced every few thousand years. About 0.02 percent of the oxygen would have to be replaced every year. In a mere million years of human habitation on terraformed Mars, the oxygen in the atmosphere would have to be replaced over two hundred times. And that seems very wasteful to me. Instead Mars should be made a shellworld. > > A shellworld[1][2][3] is any of several types of hypothetical megastructures: > > > A planet or a planetoid turned into series of concentric matryoshka doll-like layers supported by massive pillars. A shellworld of this type features prominently in Iain M. Banks' novel Matter. > > > A megastructure consisting of multiple layers of shells suspended above each other by orbital rings supported by hypothetical mass stream technology. This type of shellworld can be theoretically suspended above any type of stellar body, including planets, gas giants, stars and black holes. The most massive type of shellworld could be built around supermassive black holes at the center of galaxies. > > > An inflated canopy holding high pressure air around an otherwise airless world to create a breathable atmosphere.[4] The pressure of the contained air supports the weight of the shell. > > > Completely hollow shell worlds can also be created on a planetary or larger scale by contained gas alone, also called bubbleworlds or gravitational balloons, as long as the outward pressure from the contained gas balances the gravitational contraction of the entire structure, resulting in no net force on the shell. The scale is limited only by the mass of gas enclosed; the shell can be made of any mundane material. The shell can have an additional atmosphere on the outside.[5][6] > > > <https://en.wikipedia.org/wiki/Shellworld> So Mars can be made the third type of shellworld, with the shell keeping the dense atmosphere below it from escaping, with giant airlocks in the shell for spaceships, and a thinner atmosphere above the shell to stop meteoroids. The shell would also prevent the solar wind from knocking away atmospheric particles. Three) The Moon. You wrote: > > Let's lay down some assumptions. Humanity has access to 1.5% of the Sun's solar energy output, a planet's worth of elements and mass, as well as water (from Saturn's Ice Moons), excess gasses from the gas giants (Titan is a natural park of sorts) such as methane and nitrogen, and the ability to deploy an artificial magnetosphere to shield Luna. The moon has a daily period of ~70 hours, so it won't freeze at night, and if you have a problem with that then you can take it up with Venus. > > > The Moon has a sidereal rotation period of 27.321661 days or 655.71986 hours, and in its present orbit around the Earth and the Sun it has a synodic rotation period and day of 29.830589 days or 715.93413 hours. It would be incredibly wasteful of energy to change the rotation period of the Moon to about 70 hours. It would be much easier to build giant sun shades orbiting the Moon. Their orbital period would be such that the Sun facing side on the Moon would have alternating light and dark each roughly 12 hours long. The inner sides of those sun shades, facing the Moon, would also be reflective. So the Sun shades passing over the dark side of the Moon would reflect light down onto the surface, and there would be alternating 12 hour periods of light and dark, just as on the sunward facing side. The Moon has an escape velocity of only 2.38 kilometers per second, less than half of Mars's. So gases would escape from the Moon much faster than from Mas, so it would be even more necessary to make the Moon a shellworld with a shell keeping the atmosphere from escaping into space. [Answer] > > Thus, my question: How would humanity "terraform" the moon, i.e. give it a friendly atmosphere? > > > Short answer: they wouldn't. Even if it were possible, it would be so horribly uneconomical and slow that it would make no sense whatsoever. (It would probably be much easier to bioengineer humans so they don't need outside air and can tolerate vacuum, or transfer our consciousness into AI which doesn't need those pesky planets or whatever. But I digress). Also, you say "terraform" which usually means making it fit for unprotected human life for many generations - which is usually much more than just having right amount of breathable gases in the atmosphere. To mention just a few: * there are big radiation issues (there is no magnetosphere to protect from either the [sun SPE or more energetic GCR sources](https://www.nasa.gov/analogs/nsrl/why-space-radiation-matters)), * prolonged exposure to hugely reduced gravity has serious [health issues](https://www.nature.com/articles/s41526-021-00171-7) for humans (there is a reason why we try to keep astronauts stay on ISS less than a year - and those are prime specimens. While we haven't tried staying on moon for long periods of time yet, it is quite unlikely it would be harmless), * (biggest issue) that regolith is deadly microdust which will tear your unprotected lungs to shreds in days if not hours even if tiny amounts are raised in the breathable air (and there will be incredibly huge amounts even produced by one man walking, unless you put tarmac like substance over 100% of the moon) So there would literally be hundreds of better ideas to use those resources available if you want to make habitats for humans, or terraform other planets / moons, or build generational ships to move to other star systems to avoid all-eggs-in-one-basket situations in the future etc. --- But let's say they're doing it for sentimental reasons, and they don't care about huge amount of resources wasted, and they only care about "i.e. give it a friendly atmosphere" part of your question, and not about making it actually livable unprotected outside (i.e. "terraforming"). With that level of technology (1.5% sun output, harvesting outer planets, antimatter war) you'd likely be able to collect appropriately sized [primordial black hole](https://en.wikipedia.org/wiki/Black_hole#Primordial_black_holes_and_the_Big_Bang) or few, and put them in the middle of the moon to gain enough gravity. That would allow you to easily keep the gasses and reduce many of the problems mentioned above. The biggest one that still remains is the regolith - even the tiny activity of moving humans/vehicles, or a tiniest wind (now that you have atmosphere, you have that problem too) would raise that razor-sharp particles from the regolith into the air and make it *exact opposite of "friendly atmosphere"*. I mean, even without air to carry it around, [moon dust would destroy sturdy EVA suits in a matter of months](https://history.nasa.gov/alsj/TM-2005-213610.pdf). Now imagine its power being amplified several orders of magnitude by atmospheric winds, and unprotected humans... Gruesome scene, they would've likely been better if they were directly hit directly with those antimatter weapons in the first place. So you'd still have that "tiny detail" of needing to remove or contain all that regolith surface of the moon and replace it with something less deadly. Which is nigh impossible** with technology levels you mention - assuming war surplus of antimatter is not enough to turn all surface of moon to glass? Even it were, you'd first have to evacuate moon, nuke it and let it cool, and then put the gases in and re-settle it again. Hardly economical or practical. Some sort of insanely capable and quick reproducing nanobots might be able to do the job non-destructively given enough supplement materials, energy and at least a few dozen thousands years (or more likely millennia), but until that is completed your population would have to stay inside moon domes. ]
[Question] [ In my story, there is a 10 meter wide room with a 'special box' in the middle. The box is represented in the picture with the blue outline. [![enter image description here](https://i.stack.imgur.com/q71Hy.png)](https://i.stack.imgur.com/q71Hy.png) The box is 2.5 meters wide. So when you measure from the left wall of the room to the box, you should get 3.75 meters. What makes the box special is that, when you measure the distance, you get 5 meters instead. The same phenomenon is observed when you measure the distance between the right wall and the right side of the box. It is also 5 meters instead of being 3.75 meters. ( The box is 2.5 m in length, 1.5 m in width and 1.5 m in height). This special box in the story obviously does not take up space, but is still there sitting in the room. Can you guys suggest what kind of space-time phenomenon/space warping phenomenon/ physics phenomenon , no matter have farfetched, would help create such a phenomenon? [Answer] # Extra Dimensions In two dimensions your box works like this: [![enter image description here](https://i.stack.imgur.com/YknRW.jpg)](https://i.stack.imgur.com/YknRW.jpg) Spacetime bulges near the box to put more space between the walls. The two red lines are 5m even though they do not reach the middle of the room. They get the extra length by moving upwards rather than staying on the flat plane. Note the ants living in this universe cannot see in the up-down dimension. Light follows the curve of the surface. To them, the curved red and blue lines appear to be straight lines. They cannot see how the space extends into an extra dimension. They can only add up how the distances are not what they are used to. Your box works the same way. It creates an extra-dimensional bubble that lets it have more space inside than it should. As you move the box around, the bubble moves with it. [Answer] # Curved Walls and Floor! This is a bit of a deviation, since the room is special, not the box, but I want to mention it as an alternative. If the grid itself is on a curved surface, you can have right-angled and "flat" walls but still have these funky measurements without, say, generating crazy strong tidal forces due to enough gravity bending spacetime in such a small space. Instead, you need something like [Star Trek's Gravity Plating](https://memory-alpha.fandom.com/wiki/Gravity_plate) or the funky gravity generation to be under the floor. Now, depending on the length of the room and the curve of the surface, this becomes more or less noticable to your average human. The "tall" dimension on the drawing wasn't really specified, so that is variable to play with. (It will likely be more like a hall than a square room.) A person would be able to tell that something is wrong with this room/hallway, but close examination of walls and corners reveals all right angles and flatness. Something similar happens in CS Lewis' [Out of the Silent Planet](https://en.m.wikipedia.org/wiki/Out_of_the_Silent_Planet) with a room in a spherical spaceship. [Answer] Your box is a hologram. [![hologram rhino](https://i.stack.imgur.com/B3eZq.png)](https://i.stack.imgur.com/B3eZq.png) [Amazing Must See Technology 7D hologram Shown in Dubai, Poland and Japan](https://www.youtube.com/watch?v=4N0Ewb_OVsU) Depicted: hologram rhino. The box is projected on a transparent screen which is effectively 0 width. If measured by a tape measure laid on the floor under the box the box is 2.5 meters wide. If you truck out there with a tape measure you do not meet resistance until you get to the screen. Then you leave fingerprints on it groping it up like you do. You had to go right from the fried chicken to the hologram screen didn't you. [Answer] Here's a simple two-dimension solution that works in our boring 3-dimensional world. Simply turn the box at an angle. Now there are several ways to, "...measure the distance between the right wall and the right side of the box. It is also 5 meters." [![enter image description here](https://i.stack.imgur.com/JHIWo.png)](https://i.stack.imgur.com/JHIWo.png) The image suggests the box and room are orthogonal, but it is not constrained as such. Even an imperceptible angle of 0.0001 degrees would allow these measurements to be made. Similarly, the description does not say at what point on the box you measure to. ]
[Question] [ So the premise is that life under the sea and life on the ground has evolved independently and achieved sentience. Finally, the land creatures (I'm using humans for now because of simplicity, I'm still working on this) reach a level of technological sophistication where they can travel underwater and can reach the mesopelagic zone. I want the people underwater to have a similar level of sophistication, maybe a little bit behind, but the question is would it make sense for them to have evolved limbs with finger-like appendages and if not, how would they build homes and such. [Answer] Oh, they have already. [![Fish with hands and an ugly expression, also a crest.](https://i.stack.imgur.com/MG7mS.jpg)](https://i.stack.imgur.com/MG7mS.jpg) Image copyright Gettyimages, Auscape This critter prefers walking on it's fins, it has shoulders, elbows and wrists, it's "hands" have finger-like projections which extend beyond the webbing which fish normally have. Living in Tasmanian river estuaries and being a slow mover along the bottom most of the time, the [Spotted Handfish](https://en.wikipedia.org/wiki/Spotted_handfish) can swim when needed, but prefers to pootle along on it's modified pectorals (and caudal fins in some related species giving them four limbs). There are many indications that the first [tetra-pods emerged around 380 million years ago](https://en.wikipedia.org/wiki/Evolution_of_tetrapods#From_fins_to_feet), and were exclusively underwater when they did, an eye-blink in evolutionary terms lead to hands and feet, your creatures might quickly manage to evolve these features in a few tens of millions of years, maybe fewer if their genes/environment permit. Given time and sufficient evolutionary pressure, articulations in those fins resembling fingers evolve by the same developmental signal for the proximal joints recurring, might move distally (as happened to create the elbow/wrist in the first place), and their webbing might recede; perhaps if winkling small prey out of difficult crevices were an advantage. The big hurdle you'd have then is the energy and incentive to develop big brains. For primates, dexterity and brainpower to use it seem to have [developed together](https://en.wikipedia.org/wiki/Hand#Evolution). Tricky problems (like prizing open a clam for the flesh) requiring manipulation of objects as tools offer the incentive and energetic reward to "grow brains and fingers. Tool use proper would then come into play. [Answer] If you look at our seas, the closest appendices looking like limbs have been developed by cephalopods, starfishes and crustaceans. They are nowhere close to the complexity of human fingers, but at least in the case of the octopus they allow for quite some degree of manipulation, followed by crustaceans. Considering that fingers have evolved after a long series of modification from some fish fins and you are excluding this path, I think it's more plausible if you move along the tentacle path or the crustacean path. [Answer] Of course they could, because they did. I reference the transitional fossil fish [Tiktaalik](https://en.wikipedia.org/wiki/Tiktaalik). While it hadn't yet developed fingers or toes, it had definite limbs. The front pair had shoulders, upper arms, lower arms, and wrists. Now, this seems to have evolved to help push the animal out of water so it could use its primitive lungs in cases of oxygen-poor water. What theoretically could happen is that this evolved in fresh or brackish environments, and after the creature developed gasping fingers, it moved back out to sea. If it wasn't an open-water swimmer but tended toward living on the substrate, then the limbs could have retained functionality for moving around underwater, looking for prey, and eventually tool use. Again, an analogous sort of thing has really happened. The bony fish have a swim bladder, which is believed to have evolved from a primitive lung that was developed by a group of fish that lived in that same type of environment, migrating back to the marine environment but retaining the gas-filled organ, using it for buoyancy instead of being a lung. [Answer] Your problem will be having a fully aquatic water breathing species reach near human levels of technical sophistication with or without limbs! In order for humans to reach mesopelagic zone deliberately (going down in a sinking hip doesn't count) as mentioned requires 20th century levels of technology. That means high level metallurgical skills, mastery of electrical engineering, industrial chemsirty and all the academic and practical skills associated with a civilization capable of that feat. Your aquatic species will have none of that, no metallurgy - not even simple spear tips or knives, no electrical engineering or non-water based chemistry, no nuclear physics, astronomy etc etc In short it won't be a meeting of near equals but rather that of a technological backwards culture meeting an advanced one. Which never tends to end well of the former. They may have advanced knowledge of mathematics, aquaculture, organic chemistry and acoustics etc. But what they will lack is the ability to apply that knowledge in practical ways because they won't be able to make the tools necessary to progress applied science and engineering. ]
[Question] [ This question already has answers here: [Could humanity survive the sun going dark?](/questions/9679/could-humanity-survive-the-sun-going-dark) (8 answers) Closed 3 years ago. Let's say, whether for magical or scientific reasons, Earth and the moon are separated from their star, the Sun, and are sent hurtling through space. Ignoring the reasons for such an event, how could humans survive for at least 1,000 years, if they could survive at all? [Answer] If there is little or no warning, there is no chance of survival. However, with some preparation, it is feasible to survive deep underground - a few km would do. The interior of the Earth is quite warm, to the extent that for every km you go underground, the temperature rises 25–30 °C (the [geothermal gradient](https://en.wikipedia.org/wiki/Geothermal_gradient)). Earth's internal heat comes from a combination of residual heat from planetary accretion, heat produced through radioactive decay, and latent heat from core crystallization. The sun only heats the top few metres of the Earth's surface. Hence, keeping warm is not a problem. There is also plenty of water underground in [aquifers](https://en.wikipedia.org/wiki/Aquifer), which can go as deep as 9 km or more. Air can be recycled, but it will still be present on the surface as frozen air, which can be mined. For energy, [geothermal energy](https://en.wikipedia.org/wiki/Geothermal_energy) is an obvious solution. Nuclear power could also serve, though storing the nuclear waste might be a problem. Ejecting it to the surface is no good if you want to live there after only 1,000 years. With heat and energy, you can grow crops under artificial lighting and even keep a few animals like dairy cattle, chickens, and perhaps sheep for wool, milk, and meat. Some places may be more suitable than others, like Iceland, which has many [hot springs](https://www.nordicvisitor.com/blog/best-iceland-hot-springs-geothermal-pools-guide/) that provide ready heat and energy near the surface. You would only need to dig down far enough to have protection from meteorites once Earth's atmosphere freezes. The greatest challenges for survival for a thousand years will be to maintan the knowledge to maintain the machinery that keeps underground cities running and to preserve biodiversity and genetic diversity. The latter could feasibly be managed by storing seeds and fertilized eggs in permafrost near the surface. [Answer] With the Sun gone, so is the motor of the food chain, if we exclude the life forms thriving around the volcanic chimneys deeps in the ocean. But tubular worms are yet to become a staple of our breakfast. Moreover with the Sun gone our atmosphere will turn into a layer of iced gases, laying on top of our frozen oceans. The only way to survive would therefore be to have an abundant and cheap energy source to allow humans growing plants, keep their shelters warm and supply their industry which has to produce literally everything that is needed, as nothing will be spontaneously available in nature. I think this calls for nuclear fusion, integrated here and there by geothermal power. [Answer] Given a few years of warning, humans could survive in bunkers deep beneath the ground, relying on nuclear power to heat their habitats and run the grow lights in their farms. Not everyone could be saved, in fact the vast majority would die. But a few hundred thousand, maybe 1 million, could take refuge in underground settlements all around the world. Nuclear fusion would be nice, but isn't actually necessary. Given such drastically reduced energy demands, there is more than enough fissile material to power a society like this for millennia, especially if supplemented with geothermal power. [Answer] I think the question is interesting, but the phrase "...Earth and the moon are separated from their star, the Sun, and are sent hurtling through space." is rather vague. My response assumes "hurtling" means "at much less than the speed of light" and that the laws of physics still apply. The key is escape velocity. It could be weeks before the Earth exits the Godilocks Zone, and more weeks before significant freezing takes place. There is time, therefore to begin crash programs to dig. As the Earth freezes from the outside in, digging has to keep head of freezing. I'm going to ignore the moon for the purposes of this response, although the existence of a permanent base on the moon would definitely be a good plot line. Given my assumptions and the current level of technology ([The Boring Company](https://www.boringcompany.com)), I do think that it's quite feasible to save a significant portion of the Earth's current population. You have an interesting idea here. I'm looking forward to your first novel. [Answer] Jupiter still exists? If so, lets play an Arthur C. Clark and turn it in a new sun, just like in 2001. In his story they use monolith magic, i say let's go with the simple route and build nukes. Big ones. [![enter image description here](https://i.stack.imgur.com/4bEfr.png)](https://i.stack.imgur.com/4bEfr.png) ]
[Question] [ Both the prey (plural) and predator (singular) are intelligent and sapient. The predators are semi-solitary - they meet up occasionally to conduct rudimentary trade (think bartering), find mates and raise a family. They'll teach their children hunting skills and tool use, but they spend the rest of their lives alone. They don't mate for life and don't maintain strong ties to family. They don't have stationary homes and wander around instead, creating and discarding simple shelters as they go. They can hand-sew bags or preserve meat using salt, which gives you an idea of their technology. They haven't learnt to make weapons because they already have extremely powerful claws and jaws. Note: prey is plural here. There are multiple prey species which are all intelligent and sapient. I will give an overview of their abilities here. Their tool use, like the predators, is fairly basic. Among their abilities are hand-sewn clothes and bags, simple food preservation using honey or salt, and the creation of items such as boxes or simple beds out of wood and cloth. The prey (plural) usually live in stationary homes, typically rough log cabin-like structures made out of branches, or systems of burrows or caves. Their homes are scattered around, not organised into villages and towns. They aren't semi-solitary like the predator, but they don't have much of a social structure either. They usually live in small family units which share one house. Different family units may meet up to find mates or conduct barter/trade. The predators are obligate carnivores, so they can't eat plant matter to stave off hunger. The predators can preserve meat using salt to avoid killing for longer. Let's say, between the two societies, they come up with this system: * Each week, a few of the prey species die natural deaths. * The bodies of these dead members are left in a clearing, which the predators know about. * The predators collect the dead bodies and eat them. No killing is involved, and the predators and prey can maintain friendly relationships because they don't live in fear of one another. In your answer, if possible, please include population sizes and prey mortality rates that would make this system feasible. It doesn't need to be hard science; just a rough estimate. *Edit:* The comments made me realise that I'm probably going to have to go back to the drawing board on this one. However, I'm leaving the question up for posterity's sake. [Answer] I'm not sure it could work as described. The main problem is that unless the prey species is involved in large scale warfare or something else resulting in massive death of healthy individuals, the vast majority of deaths are going to come from some combination of disease, malnutrition, and old age. Unfortunately for the predators, bodies from any of these categories are low in nutrition at best and possibly deadly at worst. I've done some very basic math below to try and get a grip on what relative population sizes would have to be. According to Gurven and Kaplan at UCSB (<https://gurven.anth.ucsb.edu/sites/secure.lsit.ucsb.edu.anth.d7_gurven/files/sitefiles/papers/GurvenKaplan2007pdr.pdf>), in hunter/gatherer societies all violent and accidental deaths account for almost 19% of total mortality. Infectious disease causes around 70%. If we make the optimistic assumptions that all violent/accidental deaths and half of deaths from disease are edible, that means that about 54% of prey deaths will result in the predators gaining food. Assuming that the prey species has a similar death rate to human hunter/gatherers, using the data for the Hadza hunter/gatherers gives a number of 125 deaths for 706 individuals over a period of 10 years. This leads to around 1.8% of the population dying every year, meaning that a little more than 0.9% of prey individuals are eaten a year. If both predator and prey are roughly human sized, then the predators will need somewhere in the neighborhood of 2200 calories a day, plus or minus a few hundred depending on their size and amount of exercise. According to James Cole (<https://www.nature.com/articles/srep44707?utm_source=commission_junction&utm_medium=affiliate>), the average human male contains around 143,000 calories. However, once you remove bones, teeth, and places likely to be infected (brains, lungs, and gastrointestinal tract), you are left with an upper limit of almost 113,000 calories. This is 51 days of energy for the predator, so each predator will need to eat about 7 prey a year. Because of this the ratio of dead:alive prey is 7/778 per predator, meaning that there must be a minimum of 785 prey for every predator. A stable breeding population of a few hundred predators will require hundreds of thousands of prey. You can tweak the math but it won't change the fact that the predators are going to be outnumbered and/or outweighed by hundreds to one, to the point that the predators are so insignificant compared to the prey that the relationship between them is trivial. However, if you like this idea, there are ways to make it work. The first few that come to my mind are: The predators could have a technological advantage over the prey. If there was no technology gap, the prey could wipe the predators out with virtually no effort and eliminate the potential threat they posed. Even if they have ethical concerns about eating unwilling prey, they probably have no problem defending themselves. However, you would have to hit the sweet spot with advanced enough tech to defend against any threat, but not advanced enough to grow meat from stem cells. This could work, but would probably lead to a much colder relationship between the species than you described. Another way would be if the prey species was constantly involved in warfare (or some other activity with a high death count). Increasing the prey mortality rate would help even the numbers gap, but there would still me many more prey organisms. This would change the relationship up a bit. To the prey, the predators could simply be an efficient way of disposing the bodies. This would provide some building blocks for the culture of both species. Who are the prey fighting, and why? Are the predators trying to keep the conflicts going to ensure they have a food supply? If they are, what measures are they taking? For a less gory and to me much more interesting approach, make it so that the predators largely subsist on other species, but eating the dead of the prey has some religious/cultural meaning for both species. The relationship was formed for some reason in the past, and continues to be practiced, perhaps to reaffirm the friendship between the two species. I think a relationship like this would lead to the best relationship between the species, but the predators would still be predators. If you wanted them to be entirely opposed to eating live meat, this could be the eventual development of a situation like the first one I described, after the predators have gained technology to grow meat or otherwise overcome being an obligate carnivore. There are of course many other ways that the relationship could work, I just felt like sharing some of the best ideas I could come up with. [Answer] No, unless... the predators limit their own population in order to match the natural death rate of the prey. As soon as there are more predators than there are naturally dead prey, that means either a predator is going hungry or a prey is going to be hunted. How likely is it that the predator is going to go hungry? How likely is it that the predator society will "rebalance" their numbers by eliminating one of their own? Some would say not bloody likely at all. Let's factor in environment and go to the logical extreme. Let's say the ecosystem is at max capacity for prey, i.e., the prey are at max possible population for that ecosystem. The predator population can grow to consume the number of naturally dying prey. Then add one more predator. Now the predator population is feeling some stress. How will it react to that stress? There are many ways and many reasons that species limit their own numbers. A new alpha lion notoriously will kill off the cubs of the preceding alpha. Many species, say crocodiles, will indiscriminately eat the young of its own species. And of course there's always straight up cannibalism and of course, war. Chimps go to war. Ants go to war--even between colonies of the same species. While none of these actions are specifically undertaken with the goal of controlling the population of one's own species, maybe this predator prefers to do one of these things before choosing to kill prey. (Which also would need some 'splainin.) [Answer] If a non-sentient predator gets hungry, it will kill someone, so in that case this arrangement couldn't be stable. But if the predators are capable of long-term planning, then I don't see how this would make any difference to the basic ecology. It's just like the human transition from hunter-gatherers to farmers: you still need the same ratio of food to mouths, but organising the process lets you spend much less energy and have a much more stable food supply. If the predators mostly don't have to worry about hunting, they can spend their time doing science or art or working in a bank; they're not going to throw that away just because they're temporarily hungry one day. And perhaps more to the point, they're not going to tolerate each other behaving like that. The rate of natural deaths might fluctuate, but on average, as long as the prey population is big enough, then there will be a steady supply of corpses. If the predator population gets too large, then some of them will starve. But reverting to killing won't make that problem better; in fact, it will rapidly make it worse, in addition to breaking the beneficial long-term arrangement. There are lots of different ways this situation could play out (see: most of human history), and some of them would involve violence and collapse, but some of them wouldn't. In general, though, the consensual arrangement is the most efficient for both predators and prey. Regarding exact numbers, it would depend on the relative sizes, how much food a single predator needs, etc. But the consensual aspect makes no difference; a kilo of meat from natural causes is the same as a kilo of victim meat. Actually, the predators would need a little less food because they're saving energy on hunting. [Answer] I almost feel it would make more sense for the prey to offer the predators sacrifices rather than naturally dead individuals. This is because I feel that the predators wouldn’t get enough food from natural deaths. Maybe the prey species has an annual raffle. Whoever “wins” the raffle gets murdered, then offered to the predators. [Answer] The closest thing would be carrion birds, which subsist off of dead animals. But they generally don't go after living things, so they wouldn't really be a threat to your prey. But if you're looking for a steady population that only subsists off of naturally-dying members of its prey, this might give you some ideas. [Answer] Evolution gives predators that can kill live prey a distinct advantage. They can take control of their own reproduction by means of taking prey rather than waiting for prey to die. With a larger subset of food, these predators can pass on more of their genes. Think about it this way, if you had a fast growing population of prey, and you were a scavenger, you'd have to wait for them to get old and die to get a large portion of food. This puts a restriction on your offspring for a particular time until the prey ages. Given a predator was able to take live animals from this growing population, they would have a bigger group to feast on than those who would have to wait for the eventual death of the initially booming population. With more food while the group is growing, and more the same food when the prey dies of old age and other causes, they predator that is not strictly a predator takes the advantage in total food. [Answer] ### It could work, but only with birth control - for both predators AND prey Prey need predators to survive. This might seem counter-intuitive, but the birth rates and growth rate of most prey animals evolved to function in an environment where they are being killed off on a regular basis. Consider that humans - a species that takes over a decade to reach maturity, and can produce maybe 15-20 children in a lifetime (and even that's a stretch) would start to push overpopulation of the planet within a few centuries if they aren't being limited by other factors. Now replace that with rabbits, which can reach maturity in a year and produce nearly one thousand offspring over the course of its life. Even large herbivores like cows reach maturity much faster than humans, which can create significant population booms if nothing is killing them off. The takeaway: If predators stop killing prey, the world will very quickly fill up with herbivores. Plants will be wiped out and then mass starvation will kill the society. The only way for a predator-prey civilization to work is if they all learn to control their own birth rates very early on. Herbivores will be limited by the population of available plants, while carnivores will be limited by the expected birth and natural death rates of herbivores. (Herbivores must greatly outnumber carnivores, naturally). They will have to be very careful not to exceed the allowed limits, or they will face society-wide famine, likely leading to both reverting back to their primal state in order to survive. Enforcing birth rate laws will be one of the main roles of the government in this society. These laws will likely change over time as well, depending on circumstance - new farming technology, like vertical farming, will allow for larger populations. This setup will likely be harder on herbivores than carnivores. Many predators, particularly apex predators, already have natural birth control instincts modulated by their available food sources. Herbivores usually lack these instincts, since in the wild they can depend on predators to keep their numbers at a manageable level. It may also have interesting effects on the development of medical technology - since reducing the rate of natural deaths can create temporary food shortages for carnivores. [Answer] What if predators are of one sex and prey of another. Predators know they cannot afford to kill off whole prey because it would mean extincion. Self-sex predatory would be not possible due to toxic blood or hormones for instance. (Did you know human blood is actually toxic to other humans?) ]
[Question] [ It makes sense to me that the best food in an underwater dome complex would be fish. Considering the massive amounts of aquatic life in the vicinity, it could work pretty well. However, I can't think of how the people would actually catch the fish. They need to be able to breathe, so an airlock leading into a section of ocean wouldn't be useful (assume there is no underwater breathing technology nor submersibles available). I've thought about some sort of net to catch them, but I'm not sure how the fish could be moved into the dome from there without flooding the place. If there were a way to catch fish on the sea floor (lobsters, crabs, etc.) easily, that would also work. Assume the technology level when building the domes is that of today, but there will be no communication or supply deliveries from anywhere outside the domes (so nothing that would require extensive maintenance or consume too many non-renewable supplies). Any ideas? [Answer] > > They need to be able to breathe, so an airlock leading into a section of ocean wouldn't be useful > > > Well, not so much. [Freediving](https://en.wikipedia.org/wiki/Freediving) is very much a thing, after all, and has been for quite a considerable length of time. People have been able to variously dive to over 100m, swim hundreds of metres and hold their breath for about 10 minutes (probably not all three at once, mind you). You can look back centuries to find traditions of people diving without breathing gear to recover wrecks, pearls or food. Plenty of interesting stuff out there... have a read about [ama](https://en.wikipedia.org/wiki/Ama_(diving)) divers, for example. Once you're out in the water, [spearfishing](https://en.wikipedia.org/wiki/Spearfishing) is a reasonable technique, and one often used in combination with free diving. So all you really need is a [moon pool](https://en.wikipedia.org/wiki/Moon_pool) or fast cycling airlock and a bunch of people willing to practise apnoea. Now, the issues of diving illness and long term human viability at depth, that's a different matter... --- Edit to add some alternative food sources Remember that whilst fishing can be a very effective source of nutrition, it needn't be the only game in town and alternatives may be easier to arrange. Shellfish are one good possibility... [oysters](https://en.wikipedia.org/wiki/Oyster_farming) and [mussels](https://en.wikipedia.org/wiki/Mussel#Aquaculture) are already farmed commercially. They have potentially useful byproducts (shells, pearls) and perform useful ecological services such as removing carbonates from the water and filtering out nutrients that might otherwise cause problems ([like poop from fish farming](https://en.wikipedia.org/wiki/Integrated_multi-trophic_aquaculture)). Mussels can be farmed on a rope, and the whole lot hauled in for harvesting without anyone having to take a dip. Many varieties of [seaweed](https://en.wikipedia.org/wiki/Algaculture) and other algae can also be farmed if you are high enough in the photic zone for them to thrive. Not just useful for food, but you can use them to make other handy raw materials like fuel or plastic feedstocks. In either case, you don't necessarily need constant hands-on work to get your food, making the logistics of the whole thing much simpler. [Answer] Underwater domes will probably be located deep in the oceans. If you are under one of the major oceanic currents, then all you need is [some dynamite](https://en.wikipedia.org/wiki/Blast_fishing). Find a school of fish far enough from home for a blast to be safe and... well, blast. The fish will all die or be stunned, and they will float to the surface where a ship can gather them. mostly sink to the seafloor where they could be easily picked up (thanks Dubukay for correcting me). The oceanic current will make sure that more fish will eventually pass by. The advantage of this method is that since water is incompressible, explosions tend to have a far greater blast radius than in air, making fish much easier to catch with explosives than birds or game. [Answer] [Fish traps](https://en.wikipedia.org/wiki/Fish_trap) are a convenient way to catch fishes and other sea creatures. > > A fish trap is a trap used for fishing. Fish traps can have the form of a fishing weir or a lobster trap. A typical contemporary trap consists of a frame of thick steel wire in the shape of a heart, with chicken wire stretched around it. The mesh wraps around the frame and then tapers into the inside of the trap. When a fish swims inside through this opening, it cannot get out, as the chicken wire opening bends back into its original narrowness. Contemporary eel traps come in many shapes and sizes and are constructed of many materials. In earlier times, traps were constructed of wood and fiber. > > > [![fish trap](https://i.stack.imgur.com/IerB0.jpg)](https://i.stack.imgur.com/IerB0.jpg) Just put a suitable lure into the trap, and when the catch is done, pull the trap into a load-lock which you will evacuate from water before letting human access it. [Answer] Depending on the level of scientific realism you want, it should be possible to enable rod and reel "sport" type fishing activity from your underwater dome (even if the dome itself is kept at surface pressure, i.e. the humans inside aren't "saturation divers" spending long periods at depth pressure. First, you need a "waldo" type manipulator system. These have existed for decades in deep diving submersibles; in this case, it would be optimized for the movement of the reel crank, a little casting motion, a sensor to feel the line tension (to detect bites). This lets the fisher operate the rod and reel in a "moon pool." The "moon pool" is a sea-pressure chamber with an opening at the bottom to the sea. In surface vessels, these allow launching submersibles and ROVs from inside the hull, broadening the range of weather conditions for operations. In your colony dome, it provides a pressurized access to a water surface. The rod would be mounted by remote manipulators, or with the moon pool closed and the chamber pumped down to dome pressure. When all is ready, the pressure is brought up to match the exterior, and the moon pool opened, so that the bait or lure can be cast into the pool and allowed to trail in the outside water. Assuming a continental shelf location (as opposed to abyssal), there is still some outside light, which might be augmented by floodlights outside the dome (to attract fish). Once the bait is in the water, fishing operation would work much like surface rod and reel ocean fishing. Fish recovered through the moon pool would be stored in live wells (as are used in offshore recreational fishing), which could be sealed and brought inboard to be gradually depressurized (to cut down on exploding fish), before the fish are extracted to be consumed or sold. ]
[Question] [ I have a fantasy kingdom set up where the landscape is mostly mountainous with rock and pine forests, like the picture below. As such, it is quite difficult to have agriculture. One plant which can grow there is gorse (which can grow almost anywhere). Could a gorse bush provide for food? ![enter image description here](https://i.stack.imgur.com/3quNZ.jpg) [Answer] > > Could a gorse bush provide for food? > > > *Yes, they can not only provide food, they can provide for* food. But not just that, they have the potential to support a whole culture in many ways:** * The Tips of fresh growth contain vitamin C and other nutrients and can be used to make a refreshing tea, the flowers (available during the winter) are similarly suitable for tea. * References indicate that both can be pickled in vinegar and kept for long periods. A poisonous alkaloid it contains can be taken in moderate quantities, but don't eat too many in one sitting though. > > its flowers have been used in the treatment of jaundice and as a > treatment for scarlet fever in children. The seed is said to be > astringent and has been used in the treatment of diarrhoea and stones. > The plant is used in Bach flower remedies > > > * Both sheep and goats are used in various parts of the world to control gorse growth, goats being hardier and more suited to mountain terraine can [live off gorse](https://www.grassland.org.nz/publications/nzgrassland_publication_1218.pdf) at a density of 35 individuals per hectaire (10,000 sq metres). * They would provide your peoples with milk/cheese, meat, tools (horn/bone/glue/lighting from the fat) and dung for fuel for fire/building materials or to fertilise suitable patches of rock for herbs. Goatskin and leather for clothing/bedding, and stomachs as storage bags. Fine quality thread, woven or knitted hair, as from the [Cashmere](https://en.wikipedia.org/wiki/Cashmere_wool) or [Mohair](https://en.wikipedia.org/wiki/Mohair) goats would present a very valuable trading resource for metal tools, medicines or alternative foods for variety. [![enter image description here](https://i.stack.imgur.com/G7siD.jpg)](https://i.stack.imgur.com/G7siD.jpg) An Angora Goat (Produces Mohair) Creative Commons Attribution-ShareAlike License Wikipedia 2019 * Don't neglect the importance to your people of beer that can be brewed from the milk ([Koumiss](https://en.wikipedia.org/wiki/Kumis)). > > it can be used as a windbreak hedge in the most exposed positions, > making an impenetrable barrier with its vicious thorns. > > > * Gorse contains terpenes - these highly flammable aromatic compounds have antiseptic qualities and can be used for starting fires, treating wounds. The wood ash can be used for making a [lye for making soap](https://en.wikipedia.org/wiki/Lye), the flowers as a natural dye. * The [seed can be soaked](http://www.naturalmedicinalherbs.net/herbs/u/ulex-europaeus=gorse.php) in water and used as a wash potent against fleas. * The thorns, well perhaps your people have a passtime of playing darts. Information gathered from variously: <https://www.grassland.org.nz/publications/nzgrassland_publication_1218.pdf> <https://en.wikipedia.org/wiki/Cashmere_wool> <https://en.wikipedia.org/wiki/Mohair> <http://rawedibleplants.blogspot.com/2013/03/common-gorse-ulex-europeaus.html> <http://www.eattheweeds.com/ulex-europaeus-edible-gorse-or-furze-pas-2/> <http://www.naturalmedicinalherbs.net/herbs/u/ulex-europaeus=gorse.php> <https://en.wikipedia.org/wiki/Lye> [Answer] I grew up with gorse, and though yes, it's pokey, picky and unpleasant to try to move through quickly (especially if it grows thickly as it does on the cliffs of the island of my birth) part of the selective pressures making the resinous outer coating and the sharp spine-like leaves such an advantage is that the actual tissue of gorse is both liquid and nutrient rich... had it not those defences, it would get decimated by any grazers in its locale. Which is why goats do very well with it - their mouths are tougher than many other ungulates, so they just... chomp right on through. Admittedly, even they have to be somewhat careful, but they eat gorse and sloe bushes too, which are equally hardy and even pokier! That said, you should* research specific species of gorse* for your chosen conditions, as the one I'm the most familiar with (Ulex Europeaus) *wouldn't* do well on a higher than Tibetan plateau - though it *would* handle the inherent drought conditions well, *and* the bright sunlight, and gravelly nutritionally-poor soil as well, it *doesn't* handle harsh cold winters well - this is intrinsic to many plants which retain moisture via resinous coverings - they can't afford to freeze as there's just so much cell damage done when the plant's tissues retain that much water. Guernsey Gorse [![Guernsey Gorse](https://i.stack.imgur.com/4tuxP.jpg)](https://i.stack.imgur.com/4tuxP.jpg) Sloe - Blackthorn bush [![enter image description here](https://i.stack.imgur.com/pXYN8.jpg)](https://i.stack.imgur.com/pXYN8.jpg) Hope this helps [Answer] Collecting gorse is not called "farming". It's called "gathering" or "herding." Unfortunately, gathering doesn't provide much agricultural surplus. Your kingdoms's population will be low due to dearth of food, and will be spread widely. Herds of sheep or goats may need to range widely to gather enough sustenance. Hunting parties to bring in wild meat will be very popular...as will livestock theft. Lack of specific dietary nutrients (like Vitamin C) will stunt growth and cause early death. Your land will have some villages, but few towns. Low population and tough terrain means few roads. Your folks will spend most of their time fending off starvation instead of amassing wealth, going upon quests, or pondering the mysteries. The well-fed goats, however, will provide plenty of milk and cheese. ]
[Question] [ In a setting of late Victorian technology, would it be possible to record and replay sound and light near-real-time similar to modern video-recordings? The ideal criteria for the system would be (in order): 1. The ability to record sound inside a room (not having to be right in front of a microphone). 2. The ability to feed the signals to a central room for observation. 3. The ability to record shade (any 'resolution'). 4. The ability to record colour (any 'resolution'). I ask because I'd like my correctional facilities to be remotely supervised, but I can't figure out a CCTV-like system using the technology available. Cost or effort is not of any concern, but the simpler and more practical the better. [Answer] [Victorian Era is 1837–1901](https://en.wikipedia.org/wiki/Victorian_era). [Early period of film starts in 1890s](https://en.wikipedia.org/wiki/History_of_film#Early_period). So is it possible to record and replay? Of course, because it was done. For transmission, it is more complicated. [First prototypes was mechanical](https://en.wikipedia.org/wiki/Mechanical_television#Television_demonstrations): > > As a 23-year-old German university student, Paul Julius Gottlieb Nipkow proposed and patented the Nipkow disk in 1884 > > > As you can see, still very well in Victorian Era! Sadly, it wasn't practical then: > > By the 1920s when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems. > > > So you need to stretch it a bit, and made electrical amplifiers available some 20~30 years earlier, or make your system use higher voltages - steampunk vibes for the win! --- "The ability to record colour (any 'resolution')." Was not in the question when I was writing my answer. Still, with three disks and some color filters it shouldn't be that impossible. --- Bonus: Audio Again, looking at Wikipedia suggest that there were attempts during Victorian Era to make [something like telephone](https://en.wikipedia.org/wiki/Invention_of_the_telephone#Innocenzo_Manzetti). > > Innocenzo Manzetti > > > Innocenzo Manzetti considered the idea of a telephone as early as 1844, and may have made one in 1864, as an enhancement to an automaton built by him in 1849. > > > Johann Philipp Reis > > > The Reis telephone was developed from 1857 on. > > > Given that telephone prototypes actually were built, we can be reasonably sure sound transmission is possible. Yet again, amplifiers would help. [Answer] Theoretically you could transmit (nor record) sound and images without the phonograph or a cinematograph. Depending on the precise time you have chosen your story to take place, they could be either unavailable or too expensive to use in correctional facilities. The main issues would be precision and amplification, though. * For sound, you have probably heard of the [tin can telephone](https://en.wikipedia.org/wiki/Tin_can_telephone) as a kid. * For images, you could have a network of mirrors and lenses, following the idea of the [steganographic mirror](https://en.wikipedia.org/wiki/Magic_lantern#Steganographic_mirror). Sound can be transmitted more or less efficiently (but distorted with distance) through a linear medium surrounded by suitable materials. Sound travels farther through cables and hallways/tubes. Image can be focused first and amplified later through lenses. A bigger picture would mean lower brightness. As I said, an important issue would be precision and amplification: the further you want sound and image to travel, the better materials and more perfect mirrors/lenses you would need. A possibility to overcome this issue is a small, tightly packed correctional facility. [Answer] Avoid modern bias - just because we use electronic items now doesn't mean the Victorians would have. Instead, consider the established science of optics - where light does the work, not vulgar electricity. A periscope was first deployed in 1854, and the first prismatic lens periscopes were used in the American Civil War in 1861-5. Periscopes were used in trench warfare, submarines, tanks, naval vessels, and more recently spacecraft - the Soviet Soyuz reentry module has a periscope for observing downward, establishing a reentry angle, and docking. More info <https://space.stackexchange.com/questions/24603/soyuz-has-a-space-periscope> Downsides - you need a lot of light for an analogue optical tool to work. Early TV cameras needed lots of hot stage lights to illuminate the actors. Another way to picture this might be a much larger/longer version of a through-door viewer that some homes have installed through their front door. General reading <https://en.wikipedia.org/wiki/Periscope> [Answer] [The querent has modified the question so that instead of asking for record and playback they are now asking for television. This answer refers to the original question.] Recording and playing back sounds and moving images: * Thomas Alva Edison's [phonograph](https://en.wikipedia.org/wiki/Phonograph#First_phonograph) was invented in 1877. * [Auguste and Louis Lumière](https://en.wikipedia.org/wiki/Auguste_and_Louis_Lumi%C3%A8re) invented and demonstrated their [cinematograph](https://en.wikipedia.org/wiki/Cinematograph) in 1895. Queen Victoria reigned from 1837 to 1901. Quite obviously, recording and playing back audio and video were possible during her reign, in actual for-real history. [Answer] For arrival of signal within an hour, film is entirely plausible and, as other answers have mentioned, well within the Victorian period. Color photography was demonstrated in the 1880s (shortly after gelatin dry plate photography was invented), with panchromatic film suitable for filter-wheel color still predating 1900. Development after the introduction of organic developers (Rodinal was introduced in 1888) took around thirty minutes (develop, fix, wash) plus drying time, and a purpose-built apparatus might allow viewing the film while wet (wet printing was routinely done in the press camera era, some decades later, to get photos into newspapers in under an hour); otherwise hot forced air could dry a short film strip in a few minutes. Use of a telephone modified for greater pickup sensivity (with a horn, for instance) to drive the recording stylus on an Edison phonograph would permit the recording apparatus to be remote from the room/cell. This gives a sound recording, deliverable within the hour. This leaves synchronization, which was also managed by Edison, though after Queen Victoria's passing. If the transmission needs to be remote, you have a problem. Sound could travel over a distance of (at least) a few miles on a Bell/White/Edison telephone, but there was no method of transmitting vision at a resolution you'd call "image" at a rate faster than a significant fraction of an hour per page for early facsimile telegraphs, never mind in color. [Answer] Carbon microphones were invented in 1878. They have granules carbon between two plates. The sound causes the thickness to changes, and causes it act as a variable resistor. A battery is needed for it to work. They will drive a coil speaker. In fact a speaker coupled to a graphite microphone can be used as a low frequency amplifier. You'll also need a moving-iron speaker (around 1870), and Daniel cells for the battery (1836) [Answer] [Mołot's answer](https://worldbuilding.stackexchange.com/a/134209/8318) is basically that recording was available and transmission is the challenge. Building on that: Depending on the needs of "near real time" you could have a conveyor belt or similar mechanically rotating physical storage media in and out. You can have multiple recording systems taking turns to account for the change-out time. While one system changes out, the other records, then (possibly as soon as) the change-out is done on one machine and it can start recording, it does so and the change-out begins on the other. The changed-out media is mechanically conveyed to an observing station, which can accept two storage inputs that follow a similar automatic change-out process. When played back, the observer sees what happened delayed by the time involved in mechanically conveying the recording media back to the observation station. This would take some ingenuity and sufficient motivation, but is reasonable for the tech of the time. [Answer] <https://web.archive.org/web/19970331180604/http://www.sff.net/people/Jeff.Hecht/Chron.html> Roman Times: Glass is drawn into fibers 1713: Rene de Reaumur makes spun glass fibers 1790s: Claude Chappe invents 'optical telegraph' in France 1841: Daniel Colladon demonstrates light guiding in jet of water Geneva 1842: Jacques Babinet reports light guiding in water jets and bent glass rods Paris 1853: Paris Opera uses Colladon's water jet in the opera Faust 1854: John Tyndall demonstrates light guiding in water jets, duplicating but not acknowledging Colladon 1873: Jules de Brunfaut makes glass fibers that can be woven into cloth 1880: Alexander Graham Bell invents Photophone, Washington 1880: William Wheeler invents system of light pipes to illuminate homes from an electric arc lamp in basement, Concord, Mass. 1884: International Health Exhibition in South Kensington district of London has first fountains with illuminated water jets, designed by Sir Francis Bolton 1887: Charles Vernon Boys draws quartz fibers for mechanical measurements 1887: Royal Jubilee Exhibition in Manchester has illuminated "Fairy Fountains" designed by W. and J. Galloway and Sons 1888: Illuminated fountains at Glasgow and Barcelona fairs 1888: Dr. Roth and Prof. Reuss of Vienna use bent glass rods to illuminate body cavities 1889: Universal Exhibition in Paris shows refined illuminated fountains designed by G. Bechmann 1895: Henry C. Saint-Rene designs a system of bent glass rods for guiding light in an early television scheme (Crezancy, France) 1892: Herman Hammesfahr shows glass dress at Chicago World's Fair April 25, 1898: David D. Smith of Indianapolis applies for patent on bent glass rod as a surgical lamp 1920s: Bent glass rods used for microscope illumination June 2, 1926: C. Francis Jenkins applies for U.S. patent on a mechanical television receiver in which light passes along quartz rods in a rotating drum to form an image. ``` 1930 - German medical student Heinrich Lamm was the first person to assemble a bundle of optical fibers to carry an image. Lamm's goal was to look inside inaccessible parts of the body. During his experiments, he reported transmitting the image of a light bulb. The image was of poor quality, however. His effort to file a patent was denied because of Hansell's British patent. ``` This last 2 is the closest you can come in anything like the Victorian age. [Answer] Perhaps a [Panopticon](https://en.wikipedia.org/wiki/Panopticon) will serve your needs. It's essentially a ring or cylindrical of cells, with mostly transparent walls facing the center, and a watchtower in the center. It isn't much like CCTV, but it did allow a few guards / watchmen to observer a great number of prisoners. ]
[Question] [ In a society with near future levels of technology, the crime rate reached a high degree and the government decided to transform an island (which was a city) into a large prison, or an exile/banishment place. This is the plan: * Building a wall around the island * Leaving only one bridge as a connection with the country * Sterilizing prisoners before banishing them * The prisoners can then live freely in the island # Questions 1. How plausible is the idea of building the wall around the island? 2. What kind of law enforcement units and technologies should be used to keep the situation inside the island under control? [Answer] The [Penal Colony](https://en.wikipedia.org/wiki/Penal_colony) has a long tradition of being a thing. From Alcatraz to parts of Australia, Tripoli to Isla Maria Madre, countries and empires have moved prisoners to hard-to-reach places, very often islands. The great part of using an island is that the waters around the island become a wall for you. [Alcatraz](https://en.wikipedia.org/wiki/Alcatraz_Island) famously had treacherous waters surrounding it, which are [cold and pulls things](http://www.discovery.com/tv-shows/mythbusters/videos/escape-from-alcatraz-minimyth/) out to the to sea. This makes excessive walls unneeded. (Indeed, Alcatraz has walls, but this is very likely to separate prison populations and to protect the civilians on the island.) So, if the island in question is small, a wall is easy to build. If it's large and the waters are particularly treacherous, then I wouldn't bother with a wall. A few speedboats is really all you need to patrol a small island. Add to this some normal prison offices on the colony, as well a substantial police force, and this penal colony is up and running! As a bonus fact: Zxyrra noted that the sterilization of prisoners would be a [human rights abuse](https://en.wikipedia.org/wiki/Reproductive_rights). Since 1968, the ability to determine the number and spacing of children according to the "Proclamation of Tehran" and was reaffirmed as a human right by the UN General Assembly in 1969. Just thought you should know when you put that into your world! [Answer] 1: It depends on the island, but generally Yes. If the geology of the island favours heavy construction around the coastline - that is, there's decent ground for foundations within a short distance of the shore - there should be no problem building a wall along it. Long walls have been built before, after all. As others have said, though, it's not really necessary - the water is your first line of defence, and all a wall is going to do is hide the prisoners from the view of the mainland. 2: This is the fun part. This prison is going to be both completely unmanageable and political suicide for the leader who wants to build it. You mentioned that prisoner's are being sterilised before being sent in there. Presumably, then, there's no intention of ever letting them out, and there's no gender segregation. Can we say "holy crap"?? You said that > > -The prisoners can then live freely in the island > > > Why do you want to provide law enforcement if they're supposed to be living freely on the island? If you want to actually control the situation on the island, you're going to need soldiers - not cops, but soldiers, fully armed and ready to shoot at the slightest provocation. After all, everyone on the island is a lifer - they have nothing to lose. There's no implicit or explicit threat of further punishment if commands are not obeyed. You don't have the normal structure of a prison, with its multiple independent security doors, remotely operated cells, regular access to shackles, etc. This means that you can't use any of the normal procedures of a prison, or any normal police procedures. The only control you can exert over people in this situation is the threat and application of force, and that means soldiers. Heavily armed soldiers with enough ammo to mow down dozens of prisoners at a time. You'll need enough of them to patrol the streets, conduct random searches of dwellings, and provide a mobile reserve to reinforce trouble spots. I don't have a calculation of how many that would be, I'm afraid. Of course, this flies in the face of the idea of the prisoners living freely on the island. If the prisoners are living freely on the island, mob rule is going to be quickly enforced. Tribalism is the most basic form of human society, and it's one we're still hard-wired to follow; it will almost certainly emerge in this prison, fast and hard. After all, this is a prison - you're not putting in a bunch of easygoing folks, you're going to be putting in a high proportion of violent individuals, many of whom probably come from a background in gangs. So, the gangs are going to re-form on the inside, and start claiming territory and resources. Resources will include slaves. The majority of women in there will likely be enslaved in short order. You've set up a scenario in which there are no moderate outcomes - you can either police with extreme force, or you can give up and allow mob rule. Neither of these options is going to make whichever politicians or legislature comes up with the idea very popular. [Answer] TL,DR: You'll get a mass escape leading to a civil war that will result in the downfall of the government which set this up, and the rise of a 'rogue state'. You're headed for trouble. You've filled a modern island city with the worst criminals you can find, have set them loose, and have given them a reason (forced sterilisation and incarceration in an unregulated environment) to be very angry with you. The resources available in a city are substantial, and in the likely event that the prisoners organise themselves to escape, you could find yourself facing an army armed with whatever they can make in their city. Given near-future tech, which may include 3D printers, machine shops and whole factories, these probably won't be "improvised" weapons either. I'll be the first to admit that there will probably be a large number of rapes and murders when the prison is first established, but these won't last. Humans instinctively organise themselves, and it is in the interests of the prisoners to exercise self-control. Those who can't will most likely be "selected against" sooner or later, leaving the more rational, organised criminals. In order to prevent this, it will be necessary to have an extreme level of surveillance, and to be prepared to kill any prisoner who appears to be organising an escape, no matter how far in the future the preparations seem to suggest that the escape will take place. Even if you implant explosives in each prisoner while sterilising them, if you miss even a few prisoners neutralising their implanted bombs or tampering with surveillance devices, they'll eventually cripple your whole surveillance network and prepare their breakout unobserved. The level of surveillance required would be such that it would be cheaper to have a regular prison with guards on-site. Implanted bombs would also have their own political cost, and I doubt that a government sufficiently lax or deluded to think that this sort of prison is a good idea would go that far. Additionally, in an area the size of a city, there will be ample opportunity for the prisoners to establish farms, thus securing their own supply of food. It is always possible for the authorities to simply destroy any farms they spot, but doing so would likely have consequences that the authorities were trying to avoid when they created this prison: the problems associated with expanding the range of crimes attracting the death penalty, and the monetary cost of supplying the prisoners with outside food as opposed to the political cost of allowing - or forcing - the prisoners to starve. In such a situation, without adequate control of the prison environment, regardless of surveillance and remote prisoner termination capabilities, I believe that a successful mass escape is inevitable. The escapees won't necessarily include the insane or disorganised prisoners who cannot control their impulses, since these will most likely have been "selected against", so the escapees will most likely resemble something that you might call a "mafia army"; organised, disciplined and ruthless in a way that regular army recruits or volunteers are seldom capable of. It is a fact that many normal soldiers, particularly conscripts, have difficulty killing another human. Normal humans are societally and genetically programmed against killing, and in combat, it is not unknown for a soldier to fail to fire or to deliberately miss. It takes quite a bit of combat experience (not just training) for a soldier to overcome this and to be fully effective. However, this "mafia army" would already have been selected to include people who were either murderers before their incarceration, or who - due to the initially unregulated environment - have already been exposed to combat conditions. With even a few real soldiers included in the prison population, it can be almost guaranteed that the "Mafia Army" will be more effective than any unit of free soldiers unless those free soldiers also have actual combat experience. The difference between this situation and other real prisons is that real prisons are either regulated internally by the authorities (e.g. Alcatraz), or if internally unregulated, the authorities can be confident that they have excluded any significant manufacturing capability and have control over supply. Once an escape has been achieved, the escapees will likely be loose in sufficient numbers that recapturing them all - if they split up - would be a massive undertaking, and by retaining a degree of organisation, the escapees could act to secure their long-term freedom - by eliminating the government that imprisoned them in the first place. Given that an escape may take years to organise, it is likely that the escapees wouldn't all simply go their own way once they were free - the prisoners who are likely to do that are also more likely to have transgressed against the prison's evolved set of laws and to have been disciplined or eliminated. This would leave the escapees loose in their parent society effectively as a guerilla army. With sufficient numbers, they could conceivably replace the government of their parent society with their own, or at the least cause internal strife for years to come. Finally, don't think that because you've sterilised these criminals that they won't find a way to reproduce. Unless you castrate or spay them (physically or radiologically), effectively removing the testes or ovaries and potentially the penis or uterus too - with the attendant political fallout that will accompany the procedure - it is possible to reverse most methods of sterilisation, and you've probably included prisoners with sufficient education to perform such reversals, whether actually qualified or not. Even if you really sterilise these criminals, and perform radical castrations with penectomies or hysterectomies with removal of the ovaries, it is not beyond the bounds of possibility (in a place as large as a city) that a few prisoners might not be able to perform stem-cell research that could result in restoration of these organs. Even if this doesn't happen, criminality is more than just genetics, it is also a mindset that can be instilled during childhood. If irreversibly sterilized prisoners escape, they could conceivably adopt children young enough to be sufficiently mentally malleable to be shaped into the next generation of criminals. Hence, while not genetically related to their adoptive parents, these children would still be the ideological offspring of their adoptive parents. In the not unlikely event that criminals escaped from this prison take over the government of their parent nation, this nation would most likely come to be viewed as a rogue nation, on the order of Iraq (under the Hussein regime) or present North Korea. If this happened in a nation like the USA, it could end up as a global catastrophe... [Answer] Why build a wall? Water is pretty easy to patrol, and a freely-living population with a whole city to play with wouldn't have much difficulty overcoming any wall you might build. As for question 2, it really depends on what you mean by 'under control'. If you want proper, Western-style prison control then you'll want some guards and use the same technology and procedures as prisons do now. You could throw in a few extras - perhaps a stunning ankle bracelet\* or similar. If you just want to stop the situation inside the prison affecting the situation outside, then just shoot anyone who tries to leave and let them get on with it, with a regular food drop. \Stunning as in 'like a tazer', not stunning as in 'oh wow, your bracelet is sooooo beautiful!'* [Answer] Don't think of it as a prison, think of it as exile. The difference between that and a prison colony (as mentioned by PipperChip) is that there is not even a pretense of responsibility for those inside. They can farm and fish for food, or not, as they please. They can elect a government, or not, as they please. Completely insane in real life, but possibly a good setting for a story. * A "failed state" like this on the border will be a constant source of instability. If it is large enough for the inmates to feed themselves with primitive agricultural techniques, the border to too long to control properly. So how do you stop the inmates from growing weed instead of potatoes and bribing guards to smuggle it out? * If the exile society comes apart, any prison sentence may be seen as something close to a death sentence. You wrote that crime rates are soaring -- what happens if respectable citizens find out that their nephew is going to be exiled for a "youthful indiscretion"? ]
[Question] [ Aluminum is the most common metal on Earth. Despite this fact, this element wasn't discovered until the 19th Century. This is because Aluminum is never naturally found in the ground. Instead, aluminum always binds with other elements and oxides like bauxite. Pure aluminum used to be a very valuable metal (even more than silver and gold). It was so valuable that the Emperor of France in the 1850s bragged that he had a set of aluminum dinner plates for only his most esteemed guests. It wasn't until the 1880s that an electrolytic process was discovered to generate a lot of pure aluminum. Backstory aside, my point is that aluminum is very common but wasn't used until quite late in human history. What if the atomic structure of aluminum was slightly changed however so that it was a mostly non-reactive element like gold? Aluminum would then be available to almost every society and be used in early history and even prehistory. With aluminum being widely available and available far earlier, could it replace bronze as the go-to metal for early civilizations? Aluminum has a melting point lower than bronze so 4th Millennium BC kilns could definitely melt aluminum. How would aluminum compare to bronze when it comes to valuable traits like hardness and elasticity and corrosion resistance? Would aluminum swords, shields, armor, and tools in general prove superior to bronze ones? Edit: Let's just say that in 4,000 BC, a bored god instantly performed the Hall-Heroult process on all aluminum on Earth. Thus aluminum becomes liquified and becomes recycled pure aluminum that doesn't need to be separated from oxygen. That way, ancient people can use aluminum without needing electricity first. I just really want to know if aluminum would be a superior/inferior metal for ancient civilizations. [Answer] > > If Aluminum was non-reactive, could there have been an "Aluminum Age" instead of a Bronze Age? > > > Sure, but that's just handwavium because... > > What if the atomic structure of aluminum was slightly changed however so that it was a mostly non-reactive element like gold? > > > You can't tweak the atomic structure like that without simply turning into another element. That's like trying to tweak the number two to be mostly like the number three. Seems to me you should already be aware of this given your studies? It would be a lot more believable if you simply made up a ficticious process that just made aluminum a lot easier to refine. > > "\Would aluminum swords, shields, armor, and tools in general prove superior to bronze ones?" > > > As far as equipping armies is concerned, it doesn't really matter if aluminum is inferior if it's that much cheaper. Remember that humans did not start out with steel, let alone modern steels. Humans started out with pig iron which was inferior to bronze. One soldier equipped with bronze isn't going to defeat two or three soldiers of equal skill equipped with aluminum. I am pretty sure that aluminum would be inferior for weapons due to it's lower specific strength (which is specified per area and by extension affected by volume). Weapons, both edged and blunt, tend to want to focus as much strength, mass, or both into as small a volume as possible to maximize applied momentum or pressure and improve handling. You can find cutting tools (specifically non-sparking ones) made of copper alloys but never aluminum alloys. (Note that virtually all "aluminum" in use is an alloyed. Unlike copper, pure aluminum only really has laboratory uses. Therefore the word "aluminum" in common usage really refers to "aluminum alloys"). The main strength advantage of aluminum comes into play when you have more empty space to work with so that you can take advantage of aluminum's lower density to use a greater volume of aluminum to make up for it's weaker specific strength without resulting in increased weight over its bronze equivalent. In doing so, you can take advantage of aspects of strength that scale with geometry (such the geometric relationship between thickness and rigidity). That means it's probably an advantage for armour. You're probably not going to mind the discomfort of your aluminum breastplate being twice as thick as a bronze one when it has 2/3 the weight. [Answer] Aside from the issues others have raised with how* you proposed to make aluminum more available... Tin was easy to smelt and used on its own for many objects, but tin was not particularly useful for armor or weapons. Tin and copper were used to make bronze because copper-tin bronze had far superior mechanical properties. Copper-aluminum bronze has similar advantages, and if aluminum was similarly available as tin to the ancients, they would likely have made aluminum bronzes, rather than trying to make weapons and armor out of plain aluminum. [Answer] My understanding is that the reason that aluminium wasn't used until after industrialization was that the refining process was energy intensive and a pre-requisite is the discovery of electricity because it can't be extracted from ore\refined in the same way as most other metals. So, I'd say that your society would need to be industrialized or to use a magic substitute. ]
[Question] [ Info: * [Apparently leather is buoyant](http://scienceline.ucsb.edu/getkey.php?key=5044). * The material composition shouldn't exceed the technology of the 1700s. * Please use the image below for a rough size comparison of the person and the dragon. * The dragon either suddenly disappears at a height or crashes in to the water in a way that is survivable and that the saddle comes free (you may choose one or both). * This person must end up being able to sleep hard for at least ten hours floating in a calm ocean covered by their cloak protecting them from exposure to the sun. * The person may be semi-conscious just long enough to get a safe position on the saddle. * The ocean conditions should be considered as ideal as possible. * If appropriate the saddle may be large enough to even fully keep the person from even touching the water. * This story device must make reasonable scientific sense, if dragons were real this must be truly believable. [![Dragon Human Size Comparison](https://i.stack.imgur.com/tXKNq.png)](https://i.stack.imgur.com/tXKNq.png) [Answer] Use Appa's Howdah. As Nosajimiki mentioned, your rider would more likely use a Howdah rather than a saddle. The only problem being that a Howdah is a bit too pretentious for your protagonist. There exist Howdahs (I think they qualify as Howdahs) like that used by Ang in Avatar: The Last Air Bender on his flying bison Appa that are very simple, modest and that could easily allow your protagonist to sleep peacefully on the calm seas. These are the only pictures I could find that show it clearly: [![enter image description here](https://i.stack.imgur.com/sXFsu.png)](https://i.stack.imgur.com/sXFsu.png) [![enter image description here](https://i.stack.imgur.com/ZjNFW.png)](https://i.stack.imgur.com/ZjNFW.png) [Answer] ## Your harness is not a saddle The thing about horse saddles is that they are designed to help keep a rider comfortable and on top of an animal while functioning as a sort of seat with your legs going off to either side of the horse's back ... but this dragon's body is far too large get your legs around, meaning you can't just sit on it with a normal saddle. You'd need a solution that lets you stay on without wrapping your legs around the dragon's body. The closest analogue for what riding a dragon would be like in the real world is not a horse, but an elephant. It is really hard to stay sitting on a charging elephant without being able to get your legs around it; so, many civilizations that utilised them in war relied on various sorts of Howdah that they could sit or stand in. Your dragon design has a much wider back than even an elephant; so, on a creature this size, Howdahs more or less go from recommended to required. Howdahs came in many, many different shapes and sizes, but many of them were large wooden structures that either resembled sleighs or towers. Tower shaped ones would certainly be more boat like, but far less likely for a dragon since aerodynamics and stability will play a bigger factor here than with elephants. Either way though, you are looking at a significant wooden structure with more than enough size and buoyancy to float on if the need arises. [![enter image description here](https://i.stack.imgur.com/gmWTA.png)](https://i.stack.imgur.com/gmWTA.png)[![enter image description here](https://i.stack.imgur.com/WsBXB.png)](https://i.stack.imgur.com/WsBXB.png) [Answer] The saddle has saddlebags To circumvent any difficulties with buoyancy or surface, why not just add saddlebags. It makes sense for such travel to have the option to store a lot of stuff for both the driver, passengers and the dragon. The saddlebags are sealed against water for air travel. Some are likely empty or close to empty, making for great buoyancy. Some might just have shed their load during the crash. Added with the saddle, you can also easily explain that there is enough surface to pass out on pretty comfortably. [Answer] ### A non-rigid saddle and tropical water, you'll be fine. Technically a human themselves is buoyant in calm water. (Human is 985 kg/m3, Salt water is 1020 kg/m3). The exposure or exhaustion usually tires you out, then a wave gets you. And then your corpse floats. A horse saddle can weigh [up to 20kg](https://www.quora.com/How-much-does-a-horse-saddle-weigh), and this dragon is a lot bigger than a horse. We could estimate this as being around 40kg in weight (the extra weight will be strapping, which is the lightest part. Which is why I'm not estimating like 200kg for this) Leather is about 860 kg per cubic meter. That 40kg leather is going to occupy 0.046 m^3. That should give an upforce sufficient to lift 7kg in salt water. That's enough to keep your head above water while you sleep. The saddle needs to lose its shape. If it keeps a "saddle" shape it'll flip. If it opens up, you'll be floating like Rose at the end of Titanic. I'd say a more important part of survival is the water temperature. 21 degree water can give hypothermia. So, you better hope your dragon ditching occurs in the tropics. [Answer] The main issue is not the buoyancy, since as you state leather is buoyant, but rather the shape. In order to ensure that the person can stay on the saddle while it is floating on the water, the shape has to be stable under the forces due to buoyancy and the person being on it. Imagine the difference between having a plank and having a pole floating on water. The plank, due to its shape, will take a greater deal to flip over, while the pole just requires a slightly movement to roll around. The shape of a dragon saddle might somehow resemble an enlarged version of a horse saddle, something roughly shaped as an upside down U with open ends. In that case I suspect it would be highly unstable, unless it has some bags on the side which, full of air, can ensure some stabilization. [Answer] As mentioned in other answers the dragon is way too big for "saddle". If flying over water is a main use-case of dragons - basically strap [Inflatable boat](https://en.wikipedia.org/wiki/Inflatable_boat) made of leather and you can survive pretty long time. Real inflatables are not be period appropriate but leather wrapped kayak-on-frame with saddle/water bags filled with air would be very believable. Also, on a dragon of the size shown in the picture, you can just put decently sized regular ocean-going boat. To makes something that incidentally floating (which is likely what you are going for) - since the dragon back is large, you need some sort of chair attached to it. Instead of strapping chair directly to the dragon use largish wooden frame and attach big air-filled leather bags on corners or large packs of reed (or any soft floating material) to have soft contact spots with the dragon's skin. This way you essentially have [catamaran](https://en.wikipedia.org/wiki/Catamaran) which gives you insane stability - with several gallons of water one could easily survive weeks on it, even in not so nice sea. [Answer] Kill the dragon and mount its body to stay afloat I'd imagine that dragons, like birds, have hollow bones and other features (feathers that trap air, large lungs to breathe fire) that make them considerably lighter than most ground animals. Therefore, its body is probably even more buoyant than the saddle and makes for a good raft. ]
[Question] [ So if you remember my dragons: 1. They aren't that big (roughly a shire horse in size, but a longer neck and a tail) 2. They use graphene in their bodies, which [might or might not explain how they fly](https://science.sciencemag.org/content/338/6109/928) 3. They have additional player classes and levels, but that's against vehicles and the Terminator. So, dragons use their breath attacks as a ranged weapon, 1. They can shoot far (~50 meters) 2. The liquid, they shoot, remains a thin stream and doesn't lose cohesion until connecting with the target. 3. They should be able to aim precisely. How could they propel their breath attacks, given these criteria? [Answer] They just need for the liquid to have a very high surface tension or even be slightly gelatinous (like [napalm](https://en.wikipedia.org/wiki/Napalm), which was developed for the same needs you have). Then they can employ a relatively simple two-chamber mechanism, with a larger reservoir chamber where the liquid accumulates, and a smaller chamber with muscle walls and a sphincter to shoot the liquid. Having the liquid catch fire at a small distance from the mouth protects the dragon from the fire (they simply need to shoot the liquid faster than its flame speed, and stop the jet at once without slowing it down; hence the two-chamber mechanism). The dragons might do that through electric discharges from the teeth, for example, or by quickly sparking together their fangs (they'd need to be made of, or covered with, some suitable substance, like flintstone). To attack, the dragon opens the sphincter between the fuel reservoir and the shooting chamber, enlarging the latter. The depression pumps the fuel out of the reservoir. Then the sphincter serrates and the muscles begin to tighten, greatly increasing the pressure in the shooting chamber. The release sphincter at the opposite end opens, and a short cartilagineous duct drives the liquid outside, past the larynx and the mouth. The teeth smash together giving off sparks that ignite the jet, exactly like a flamethrower. [Answer] You want napalm. ![enter image description here](https://upload.wikimedia.org/wikipedia/commons/0/08/US_riverboat_using_napalm_in_Vietnam.jpg) The substance which gives it its name - it's made of aluminum naphthenate and aluminium palmitate - serves as a thickening agent. This allows it to stick to surfaces, part of what made it so successful, but also means that it maintains a fairly cohesive spray. As you can see in the picture, napalm can do all the things you specify. It can be sprayed dozens of metres, with decent precision, and doesn't dissipate into droplets but remains in a steady jet. See the top answer here - [Napalm-Breathing Dragon](https://worldbuilding.stackexchange.com/questions/106623/napalm-breathing-dragon?r=SearchResults) - for how to make that work biologically. [Answer] Add long polymers. [![slippery water](https://i.stack.imgur.com/mFolo.jpg)](https://i.stack.imgur.com/mFolo.jpg) <https://www.fireengineering.com/articles/print/volume-122/issue-9/features/slippery-water-cuts-friction-loss.html> The long polymers reduce friction of the water and also make it more cohesive. A fire hose can shoot farther starting with the same water pressure. When I learned about this I learned that it enabled NY firefighters on the ground to shoot water into higher windows than had previously been possible. > > Tests of “slippery water” by the New York Fire Department indicate > that friction losses need not continue to limit flows through 1 > 1/2-inch hose to the extent that they now do. Slippery water is made > either by educting an additive into a hose line or by putting the > additive into a booster tank. > > > At a public demonstration in May, two NYFD pumpers each supplied a 1 > 1/2-inch line with the same engine pressure. The line with the > slippery water had a flow rate 50 percent higher than the plain water > line and a reach that was 40 to 50 percent better, according to the > department report. Also, the nozzle pressure on the slippery water > line was double that of the plain water line. > > > Slippery water consists of an extremely dilute solution of high > molecular weight, straight-chain polymer in water. The polymer is > polyethylene oxide which Union Carbide, the sole producer, has > trademarked as Polyox. Only 30 pounds of Polyox are enough to make > “slippery” one million pounds of water (about 120,000 gallons). > > > Your long polymers would be something soluble in whatever the dragon breath was. Biology makes lots of long polymers - bacteria make dextran and we make mucopolysaccharides. For a good dragon breathy hydrophobic liquid like turpentine, I wonder if a long alkane could serve in this role. I wonder if you could test it with a syringe? I am pretty sure I have seen the hose distance effect of polyox demonstrated with a syringe. For those wanting to get into the weeds with the physics behind how this works: <https://www.nytimes.com/1988/01/12/science/slippery-water-mystery-seems-finally-solved.html> ]
[Question] [ I'm writing a character for a fantasy setting, and I wanted him to be a gruff half-orc war master whose mount is a bull. I wanted to know if there has ever been an actual historical use of bulls or steers used as mounts, and what are some of the challenges that come from it so it could be covered a little in my story. As it's for a fantasy setting, there can easily be some suspension of belief. I wanted to add some flavor to the story and to the character by trying to address some of these challenges. [Answer] I'm delighted (and astonished) to say yes, not only has it been done but it is being done as a business. Kimberly and Annette here demonstrate just how well behaved their broken steers are. YouTube video of [Kimberly riding Jazzy, and Annette driving Dozer](https://www.youtube.com/watch?v=gVdqRLwQh_M). > > They make appearances at birthday parties, visit senior centers, go to > schools and community centers and of course are ridden and driven in > parades. > > > An article in [Horse Nation](http://www.horsenation.com/2014/09/29/saddle-yourcattle/) (of all things) tells how she finds the experience: > > “They’re a lot more ‘whoa’ than ‘go,'” she states. Friends who have > ridden gaited horses tell her that the steers feel very similar, > smooth but ground-covering. They fit into saddles with extra-wide > trees; Kimberly rides in both western and dressage saddles with > draft-sized girths. One major difference in tack is the nose bit: > rather than a bit in the mouth like a horse bridle, saddle steers are > guided by a metal bar that’s pierced through their nostrils (similar > to a nose ring for driving oxen.) > > > [Answer] I don't see much practical use in riding a bull instead of a horse, they are slower, for one, with an average top speed of just around 40km/h compared to a horse which has a top speed of 88km/h, and are considerably dumber than horses. Not to mention the most crippling problem, their eyesight. * Field of Vision- When cattle have their heads down to graze, they can see almost 360 degrees. As they raise their heads, the sides of their bodies create a blind spot behind them. This panoramic vision allows them to see in all directions without moving their heads, but they have binocular vision only for an angle of about 25 to 50 degrees in front of them. Binocular vision is like ours: Both eyes focus on an object, allowing the perception of depth, speed, and distance. Their monocular vision to the side allows them to see movement, but it is not sharply focused like human vision. * Depth Perception-Cows have slit-shaped pupils and weak eye muscles, which means they cannot focus quickly. They have poor depth perception because they have limited vertical vision of about 60 degrees, compared with around 140 degrees for humans. Because of this, they do not like to walk across shadows as they cannot tell if a shadow is a hole or ditch; they will stop moving forward and lower their heads to the ground to check it out. If your character is heading into battles or even war, the bull would not be as reliable as a war horse which has been bred for centuries for the purpose of carrying soldiers. Now regarding the orc. I'm going to make assumptions here and say that the half-orc would be around half of what an orc would weigh. According to the wow wiki (which I used as my reference) Orcs weigh between 226 - 652 lb. I'm going to assume the worst and go with the upper bound of 652 lb, which divided by two equals 326 lb. I am also going to assume that the Orc is wearing some sort of armour, and I'm going to use common medieval iron plate armour as my reference. With some searching, the average weight for full plate armour I found was between 33-55lbs, and since I'm assuming that the half-orc is bigger than a human, maybe upper 6 to 7+ feet tall, I'm going to add a few extra pounds to the upper bound, which comes to around 60 lb. (I am not going to take into consideration any extra armour/weapons/food the half-orc is carrying with him, for simplicity's sake.) Summing it up, the total weight this bull would have to carry would be roughly 386 lb on its back. This may seem a lot, but apparently, not quite. [According to this page, the Barns-ford Ferny, a Charolais bull, weighing at around 4,000 lbs could easily pull 4,000 pounds at a walking pace.](https://www.quora.com/How-strong-is-a-bull-compared-to-a-human) Taking this fact into consideration, it seems very possible for a bull to carry the orc along with iron plate armour, easily, whereas horses are only really supposed to carry no more than 20% of their own weight. (The heaviest horse in history was the shire horse, which weighed 3,360 lb, 20% of which still isn't enough my estimations for your half-orc) And regarding the history question- No. Summary: It is possible for the bull to at least carry your half-orc into battles or just to a town etc. equipped with all his miscellaneous wares. It is, however, not recommended to use a bull for battle, as they are slower, dumber, and generally more unreliable to horses. [Answer] Water buffalo! Yeah! [![buffalo race](https://i.stack.imgur.com/Mhhft.jpg)](https://i.stack.imgur.com/Mhhft.jpg) <http://www.ezytourthailand.com/packages/Buffalo-Racing.html> If you want to see some amazing images, google up the annual Water Buffalo race in Thailand. Some are being ridden solo like this one and there must also be a category for 2-buffalo chariots. These water buffalo are cooking along. This is not a rodeo - by the number of participants these buffalo must be trained to race. Water buffalo are bigger and stronger than cattle and the bulls are more docile and tractable. They have been domesticated for as long as cattle. Google image suggests people ride them not uncommonly, including a [very pretty Thai girl on a buffalo](https://www.123rf.com/photo_64379402_beautiful-asian-girl-riding-long-horn-buffalo-beautiful-asian-girl-smiles-when-riding-buffalo.html) with such big horns I wonder if they are fake. Water buffalo can run 30 miles an hour. There must be some reason why they were not historically used for cavalry but I can't figure it out. Possibly fear of too much awesomeness. Your halforc should definitely ride a water buffalo. Or better - dude is not littler than the average orc because of his human blood but bigger, like a liger is bigger than a lion or a tiger. He is a burly beloinclothed bear-sized HO; larger than the largest orc and so he must ride a chariot pulled by 2 water buffalo. [Answer] Don't worry about it. Your character is an orc in the first place. It is unnecessary for the bull to adhere to rules of a rodeo bull or any of the more docile bovine species bulls. I mean, people accept wolf riders in fantasy stories, a bull should not be that hard to tame for him, since it doesn't even need to be a "western" bull. Depending on your orcs, it's likely to have to be far larger and fierce than a western bull anyways. If in your story setting it's uncommon for this to take place, then you can take even more liberties with it because the other characters will view it as weird and noteworthy. [Answer] Yes, but, well, good luck. For one reason or another, bull-riding is a professional sport. The goal is to stay on a bull for as long as possible. 8 seconds is considered a "win." So theoretically, yes, but a word of warning: Bulls are hard to control. ]
[Question] [ In a magic-rich, Tolkien-inspired world, I am developing a system of taxation for a city-state. Centerseat is an important trade city, with many crafts being made under a guild system. Valuable magical items are also made, bought and sold here. It is located on busy trade routes and is also the most-inland city to have access by boat to the ocean. Its population and influence are now significantly less than they were when it was the capital city of the old empire that ruled the continent thousands of years ago. Legal entry to the city requires that you answer questions, with any lies likely to be detected. These are the ways I know of to tax: * sales tax * VAT (value-added tax) * income tax * property tax * inheritance tax Then there are fees: * water/sewer * school * dangerous goods (tobacco, alcohol, etc.) * fees to bring goods into the city to sell or trade (Note: small valuable items are easy to smuggle) Also in-kind taxes: * farmers give part of their crop * guilds are required to have members provide service * religious institutions contribute healing Tax collectors are likely to detect lies told by anyone they interview. Which one, or combination, of the above will generate enough revenue/goods/services to support: * security * public services * regulation (building code, etc.) * infrastructure maintenance, repair, and growth with minimal deficit spending? They should not be so burdensome that they lead to revolt, and, ideally, they should decrease the existing wealth gap in a controlled way. [Answer] First, we can't balance your budget for you. You'll have to sanity check your numbers yourself. One piece of advice : your city probably spends less on bureaucracy and services than you think. Cities did not really get that organized until industrialization apart from special cases such as Rome which was at its height just too big to do without extra administration. But that reduced administration does give some pointers on the taxes. You need taxes that are fairly simple to administer and hard to avoid. Property taxes Generally you would be taxing the means of production and generating income, not the production and income themselves. Much less bookkeeping means much less opportunity for cooking the books. Agricultural land is a favorite as it is fairly difficult to hide from tax collectors or to move to a city with lower taxes. Tax would be based on area and area ;). How large is the property and where is it located? Buildable properties within cities would also be taxed similarly. Specialized tools such as anvils, forges, kilns, or ploughs can also be taxed with preference on those too large to hide. Making noise or clouds of smoke when used is also good. Means of transport such as carriages, carts or ships can be taxed with tax tokens attached to them and occasionally checked. In many countries cars are taxed similarly today. Animals of economic significance can be taxed. Preferably large working animals such as horses and oxen. Cows and sheep can be also taxed. With horses and sheep the kind might make a difference on the tax. Such forms of wool have much higher value than others and horses bred for different purposes are quite different. Slaves might be considered means of production and taxed based on their skills. Access taxes These give you a right to do something that the authorities can reasonably stop unauthorized people from doing. An easy example from your question is entering the city. These are generally called fees rather than taxes. Examples are entering the city. Bringing a cart or carriage into the city. Bringing a carriage into roads controlled by the city. Docking a ship in the harbour. Paying for the right to reside within the controlled area is also possible. The rights and prices can have levels. A slave might be cheaper than a free man. Unless they are considered as a means of production in which case they might be more expensive. Voting rights might require a higher tax. Right to own certain property or operate a business might require a formal license and a higher fee, generally organized and enforced thru a guild system. Free work Instead of collecting taxes it is often simpler to require citizens to provide service for free (possibly with financial support provided by state for those needing it). Modern way of doing this is by tax deductions, ie. you do something the state considers valuable and can deduct the cost from your taxes but this requires too much bookkeeping for pseudo-medieval city, so flat tax exemptions or granted monopolies would probably be used instead. There is a plethora of possible privileges that can be granted. Common examples would be military service with equipment bought by the citizen, days of labour per year for city walls, roads, irrigation or other infrastructure. Administrative help is also possible with guilds for example helping with tax collection and law enforcement in exchange for privileges. [Answer] Regarding burdens and revolts, it comes down to what the citizens are familiar with. They know how it works out in practice and how bearable it is, while novel concepts might bring fears. * In a society where literacy, numeracy, and even paper may less common than today, complicated concepts like VAT or income tax may be too difficult. A flat sales tax on a few "indispensable" items sounds better. On salt, maybe. Alcohol is another option, but there would be moonshiners while salt may be imported. * [Staple rights](https://en.wikipedia.org/wiki/Staple_right). Merchants passing through must offer their goods for sale a number of days before they can go on, which encourages them to sell early and at a worse price than they'd otherwise get. * Guilds as government agencies, providing some welfare, defense and policing. Membership in a guild and guild dues are compulsory for artisans, and guilds after their widows and even form military units. * Last but not least, consider a [poll tax](https://en.wikipedia.org/wiki/Poll_tax). Unfair to modern sensibilities, but I guess you're not building a just society here. [Answer] I don't think the question as you've asked it has a determinant answer as it stands, but here's how I'd suggest arriving at one: Step 1: Draft an expense budget. How many people are employed by the city-state (soldiers, engineers, sanitation workers, wizards?) What services are provided, and to how many people? Are/how are the main thoroughfares lit through the night? Step 2: Estimate revenues from different modes of taxation until you find the blend that pays for everything without making it prohibitively expensive to live or do business in your city-state. (You could justify a vendor paying a 100% sales tax, but only if it's still cheaper than going to the next-nearest trading post at which they could conceivably sell the majority of their inventory.) Step 3: Don't forget about non-taxation revenue streams. We're talking fines, baby, the very lifeblood of the American municipality! In addition to all the myriad behaviors that can attract fines in the actual world, a big one that suggests itself is a fine for the public exercise of magic. Even if it's a generally magic-friendly society, it might be treated like a public nuisance to do it in certain places. [Answer] First of all, there is not one solution, let alone one amount of taxes, that can be considered 'the' solution. Taxes will always be considered unfair by the majority of those who pay them (even if they aren't, but people tend not to like paying taxes). The amount of taxes you need to collect is the sum of your expenses. So you may want to start with the question: What kind of services does your city provide that require money? Defense comes to mind, as in a city guard or army, and fortification. Then there may or may not be a sewage system and waste removal, you will definitely have some kind of police and jurisdiction, all of which need to be paid for. I always felt that for any taxation system to be considered at least remotely fair, the taxes should have a more or less direct link to services provide. Taxes on property are justifiable because the city-state provides protection for your property. Taxes for market access provide an opportunity to generate income. Taxes for waste and waste water removal provide those services, freeing you from the need to handle matters yourself. Obviously, taxation has always hurt the poor more than the rich. Rich people and organizations have the power to influence legislation to lift their burdens, which in turn are then carried by those without a lobby. And they have the power to persuade tax collectors to investigate easier targets first. And then there is [Chekov's gun](https://en.wikipedia.org/wiki/Chekhov%27s_gun): If it's for a story, or a game background, you should not try to find out the exact amounts, but instead check what your setup needs: If the taxes are not relevant for your story, ignore them. If the amount doesn't contribute to the story, don't mention it. For a game, go by the general ideas mentioned above, and do the balancing so it works for your gameplay. [Answer] I'm just going to get all Medieval on your answer... First, taxes aren't always money. In Medieval times this was often in grain and other useful goods. Second, instead of getting hung up on all the details of all the tax systems ever, pick a time period and a place that fits and research that. I will give you a start with the [Burghal Hidage](https://en.wikipedia.org/wiki/Burghal_Hidage) which is early Medieval period, and covers "food rent" and hide values. This is early England in the 900s. Not much of a monetary system, but certainly within Tolkien parameters. I assume nothing! There's this regarding the [Swedish system in place in late Medieval times](http://www.medievalists.net/2015/07/how-much-taxes-did-a-medieval-peasant-pay-the-numbers-from-sweden/). Notice here that certain people don't really pay in, and that STILL, a lot of it is not in cash. One thing that you will notice as you go through these is that the tax system is basically "whatever the monarchy needs at the time." And that there is the problem with your question--even narrowing to this time period, which is awfully broad... But here's the boiler plate-- in England at least, earlier taxes were based on land assessments, and it was the nobles who owned the land. It was up to the local lord to get the value owed to the crown from the peasantry/profits gained from land. The more land you had, the crown assumed (which in many periods was assessed at a particular value depending on what it produced) the more you got over a year, the more the crown wanted. The Poll Tax, which I don't think is on your list, is something they did, which was--every person over the age of 14--paid like 4 pence or something. You just paid it for the privilege of being alive and what not. Later they introduced a graduated version of it: > > In 1379 Richard called a parliament in an attempt to raise money to pay for the war against the French (later known as the Hundred Years War). After much debate it was decided to introduce a second poll tax. It was to be a graduated tax, which meant that the richer you were, the more tax you paid. For example, John of Gaunt had to pay £6.13s.4d., whereas a poor peasant was only charged 4d. > The proceeds of this tax was quickly spent on the war or absorbed by > corruption. In 1380, Simon Sudbury, the Archbishop of Canterbury, > suggested a new poll tax of three groats (one shilling) per head. > Another change in the tax was that everybody had to pay the same > amount. Most peasants at this time only had an income of about one > groat per week. As everybody over the age of fifteen had to pay the > tax, large families found it especially difficult to raise the money. > For many, the only way they could pay the tax was by selling their > possessions. > > > The peasants felt it was unfair that they should pay the same as the > rich. They also did not feel that the tax was offering them any > benefits. For example, the English government seemed to be unable to > protect people living on the south coast from French raiders. > > > John Ball toured Kent giving sermons attacking the poll tax. When the > Archbishop of Canterbury, heard about this he gave orders that Ball > should not be allowed to preach in church. Ball responded by giving > talks on village greens. The Archbishop now gave instructions that all > people found listening to Ball's sermons should be punished. When this > failed to work, Ball was arrested and in April 1381 he was sent to > Maidstone Prison. > > > Bottom line: Every single country was different, it varied from King to King, decade to decade, dependent on if they were at war and the like. Every method was used... [Answer] Remember that taxes serve two important functions. They finance the public expenses but they also steer the behavior (taxes on harmful substances, animal etc.) Basically it´s up to you which you choose, but I´ll list some plausible ones: 1. Trade fees/ Customs. These have a long history and are one of the first go-to´s. The traders have a big incentive, because there is money to be made in a big marked that the citizens of the city present. So there won´t be as much resentment, especially with foreign traders who do not have a lobby in the city. I´d expect there to be a great many different fees for import/export and depending on the good. Cheap wheat, to feed the masses - expensive wine - exemptions for local businesses etc This is basically you medieval VAT, as it is easier to control transfer of goods then sales. 2. Property tax This one is quite obvious also. Roads, wells, drains etc. have to be built and maintained. It´s only logical to have the people that profit from it also pay for it. There could for example be a yearly property tax collection, where a collector visits every property, estimate its current worth by some features and collects the rate set by the city-council. Paying tax could also elevate your status in the city, such as voting rights etc. 3. License for Business If you want to set up shop, again you have a great incentive. It could also be viewed as a good thing, as it keeps competition at bay. If you are one of only 5 licensed taverns and the city council protects you from more, you may actually favor the license fee model. [Answer] If you want to go old-school, then in-kind taxes are how you're going to raise most of your revenue. Most of your population just doesn't have enough coin to make paying someone to collect it profitable. In-kind don't just include having people give you a share of what they trade in; it's paid in what we would now consider time spent on community service, as well. Up until Napoleon, all European serfs were required to spend so many days of the year maintaining public works like roads and sewers. Also, keep in mind that D&D lore provides methods of taxation and alternatives to the g/s/cp mechanic. For instance, Berdusk has every wagon that leaves the city pay 2 cp. Very technically, there's no single monetary system in D&D beyond what's useful for your game: every city-state and nation-state mints their own coins of varying value, the various mercenary companies issue IOU's that function as bank notes within their territories, and everybody everywhere accepts gems at the exact same price with no market fluctuations. Finally, no one in these settings is interested in decreasing the wealth gap, and your commoners have no reason to expect it to be. The reason the wealth gap decreased in Centerseat is because your nobles left with their wealth when Centerseat lost its position as capital. [Answer] Most medieval taxes were indirect. Guilds pay fees to be allowed to operate in the city. Those fees are paid for by those who purchase products or services from the guild in the form of higher prices. It is easier to get money from a few people than to get it from everyone. Require fees/bribes/taxes/contributions from the nobility. Contributions could be in the form of having them run various government projects out of the nobles pockets. This lets the nobles trade some wealth for some power. This puts the burden of income generation on the nobles. This was very common. Have the government control specific markets. If the government owns the mills, everyone has to pay to have their grain milled. Or, require everyone to sell their grain to the government for the government to resell. Take a direct percentage of production. Every farmer must give X% of their produce to the government. A blacksmith must give a percentage to the government. This can be actual product or time. Often, farmers had to spend a portion of the year working the lords farms. Blacksmiths by be required to work a certain number of weeks per year for the government on government commissions. Gate fees. Have people charged a fee to enter or exit the city (or both). This both generates income and allows greater control over people's movement. [Answer] The previous excellent answers had enumerated most of the possibilities, but let me now present a "worked example": Taxation of citizens: Every citizen is a member of a guild or societas. These guilds divide among themselves the necessary public works and goods that are needed for running the city. The general types of tasks one guild has to perform are fixed by ancient custom, but the exact numbers vary yearly according to the membership of the guild. So for example the Guild of Woolloomers might be obliged to maintain a certain section of the city walls and furnish 5 ceremonial cloaks, 30 simple cloaks, 50 trousers and tunics to the magistrates (every year). While the Societas of Beggars have to clean the streets. The guilds are in turn composed of extended households of Masters. These divide the tasks among themselves, and then give it out to the household members: their sons, apprentices and assistants, and the families thereof. Most societies simply draw lots on who has to work on a given day. The advantages of the system: * Reduced corruption around public procurements. If you are in control of public money, and have to decide who to hire for a certain work (like the reconsruction of a tower) you will be tempted to award the commission not to the cheapest competitor, but to your friend or somebody who bribed you. But in this case you are interested in as quickly and efficiently completing the work entrusted on your guild. * Reduced bureaucracy: No need for extended bureaucracy to keep records on the taxes paid by individuals and the money issued for specific purposes, as the distribution happens on many levels, and on each level between people knowing each other personally. The disadvantages: * Inflexibility: If suddenly Centerstead needs something big, that it did not need in the previous years, the guilds might not be able to properly absorb the increased demand. Centerstead would still need treasury for conducting diplomacy, hiring mercenaries, and to buffer suddenly occurring large problems (like a great bridge collapses, and the Mason Guild would go bankrupt if having to rebuild it as public work) this treasury should be provided by fees and wages imposed on non-citizens: * Every time a stranger enters the city gates he has to pay a small fee. * Every time a foreign merchant enters the city, he has to pay customs in 1/30 worth of his wares. * Every time a foreigner uses a public service in the city: launches an investigation by the City Guards, makes a complaint by the Judge, requests a burial or marriage from the Chaplain, or uses the Hospital, he has to pay a fee. ]
[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/62135/edit). Closed 3 years ago. [Improve this question](/posts/62135/edit) In a fictional, alternate-reality Earth world, where euthanasia is a human right, as well as the choice to abort your own life (suicide), there are cheap, painless, widely accessible, publicly available suicide booths (as shown in Futurama (see below)). perhaps there are stringent security measures like fingerprint scan or another form of identification, and perhaps there are other medical/legal requirements like an age restriction, psychoanalysis, having your financials in order (e.g. a will) etc. If such a society where this freedom is nigh ubiquitous were proposed to a person from our world, what would be the ethical and legal, and even moral concerns raised? [![enter image description here](https://i.stack.imgur.com/hTQRK.gif)](https://i.stack.imgur.com/hTQRK.gif) —Futurama, more info on [the Wikipedia article](https://en.wikipedia.org/wiki/Suicide_booth#Futurama) [Answer] ## How can you be certain that a person is choosing to die truly of their own free will, rather than because someone wants them out of the way? Is the old CEO really choosing to end his life on a high note, or has his scheming VP tricked/coerced him into it? Is the old lady dying because she doesn't want to live any more, or because her son wants to inherit the house? Does this person really have terminal cancer, or did their doctor lie to them to get a buzz? ## How can you be certain the person understands what they're doing? Did this child truly understand what 'dying' means? Did this teenager just want to show off to their crush? Is this person suffering from depression which will respond to treatment, are they in a low point that will resolve naturally if they wait? Is this person suffering from delusions that lead them to make a bad decision? ## How cheap is human life? Even when we grant someone the right to end their life, should it really be possible to do it casually? Death is the final, irrevocable choice; shouldn't every other option be explored before that is even considered? 'Stringent' security checks like fingerprinting aren't anything like enough - the process should be long and drawn out, with opportunities to withdraw at every step, right up to the moment of actual death. [Answer] You have to look at the irrational, and criminal, applications. Suicide booths make killing yourself easy, which is a bad idea. People who are transiently depressed, feeling very guilty, or otherwise not in their right minds could use them. People who were very drunk would toy with them as a matter of machismo, and some of them would get it wrong. And so on. Suicide booths make killing other people easy, too. Whatever the security mechanisms, people will work hard to get round them. Doing so allows you to kill more or less with impunity, so it's a route to all kinds of criminal power. And if you have a body on your hands, through some embarrassing "accident" that you'd rather not explain in court, a suicide booth is an excellent way of disposing of it. [Answer] Unfortunately at one point in my life it became necessary for me to know about this sort of thing. I'm going to give you two (for now unsourced) statistics: 1. The most common factor in successful suicides is "[access to lethal methods](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3290984/)" 2. What survivors of jumping off bridges almost universally say is that on the way down they realised that everything in life can be fixed, apart from the fact they've just jumped off a bridge. ## Access to lethal methods This is a very strange term, it literally means "having some way to kill yourself" but it's stronger than that as it often refers to also having the expertise with which to use said method. Vets have the drugs, farmers have guns, these are two of the highest risk groups in the UK for exactly this reason. Normal people (in the UK) very rarely actually have a reliable accessible method with which to kill themselves. [Success rates including attempts and methods USA 2012(pdf)](http://www.suicidology.org/Portals/14/docs/Resources/FactSheets/2012datapgsv1d.pdf) note the effectiveness of firearms attempts (90% success) followed by hanging (83% success) [(BMJ)](http://injuryprevention.bmj.com/content/14/1/39.abstract) *What your booth does is give everyone* access to a way of killing themselves. By providing it you have effectively killed a large number of people who wouldn't otherwise have had a method of doing so. ## Jumping off bridges This is a key statistic, it goes with people taking overdoses then taking themselves to hospital. Far more people attempt suicide than succeed and one of the key factors in survival of an attempt is whether it's possible to stop halfway through. If the method chosen allows the person to abort, often they will. You're wanting to give them a quick, easy, reliable, painless method, but that's precisely what society works to take away. Suicide level crises are generally brief. ## Method There's another factor to preventing suicide I'm going to mention because I think this question needs it. Most people who are seriously considering suicide have a plan. That plan is fixed, it's an already solved problem that's fixated on, if you take away that method they often won't find another way to do it. Ask if they have a plan, take away access to that method of suicide and often they won't find another way. # Given the background information above, here's the actual answer to the question ## Legal Suicide is legal (in the UK), but only since the suicide act of 1961. Prior to that you could be imprisoned for the attempt or your family could be prosecuted if you succeeded. ## Moral By providing the booths, and in light of the information above, the provider could be considered culpable for every single death that occurred as a result of their use. That's around 960,000 additional premature deaths a year in the US alone. When someone is seriously considering suicide, just like any other person who is sick or injured, we have a duty to help them. Handing them a loaded gun with the safety off is not the help they need.** If they step into that booth and they're going to be in there for 4-6 hours, possibly even going to far as to have to book an appointment a couple of weeks in advance, talking to a counselor, putting their affairs in order, leaving messages for their family, having a decent meal, and free to walk away at any point, then perhaps this could be done. Then you could be said to have done what you could to help someone in need and that this is a person who has made a definite clear and conscious decision to die. A simple push a button and it's done for 25p, you'd have some questions to answer, mostly about reckless endangerment. [Suicide Prevention, how to help.](http://www.helpguide.org/articles/suicide-prevention/suicide-prevention-helping-someone-who-is-suicidal.htm) [Answer] The actual existence of a suicide booth would not change things all that much. We actually already have them in virtually every city in the nation. [![Automo-suicide machine](https://i.stack.imgur.com/MEvU1.jpg)](https://i.stack.imgur.com/MEvU1.jpg) They even come in a "lite" version, which statistics have shown is actually 4 times more effective than its full-sized bretheren. [![Suicide-lite](https://i.stack.imgur.com/Dk2nU.jpg)](https://i.stack.imgur.com/Dk2nU.jpg) (Don't worry, he's having a good time! No motorcyclists were harmed in the making of this picture) Now I am no expert in suicide, but what I have read suggests that it's not easy to commit suicide. It's not a mere matter of no longer wanting to live. The human body has too much standing in the way for that. One truly needs to want to not live to overcome that. Access to ways to do it plays a smaller part than the desire to actually make it happen. Otherwise, we'd see a lot more people driving their gas powered coffins into walls at 100mph. The more insidious question is what ethical and moral questions arose to create a society which wants to make it easy. What you describe is not the painful ritualistic Sepuku of the Samurai, but a button press to end it all. What sort of culture would want to encourage that? One potential rationale would be the collapse of society as we know it. As food becomes difficult to come by, people may resort to extremes. If enough people were wasting valuable resources on their suicide attempts (man! that phrase tastes horrible in my mouth!), the government may want to step in with a less resource intensive process. Another distopia might be one where humans have gotten so opposed to doing anything for themselves that they truly only ever press buttons to tell the robots to do things. In such a world, the lack of practice in actually doing something yourself might spur the invention of all sorts of disturbing buttons to press. Of course, at this point, ethical and moral questions regarding suicide take a back seat to the ethical and moral questions that lead to such a broken humanity. [Answer] I think that the legal concerns are the most important. To make sure no one is coerced, they could have to make an appointment at the local donation centre. (In not necessarily this order.) 1. They have to give up any/all viable organs. 2. They have a waiting period and make an appointment. 3. The reason for death has to be not about getting away with non-payment of debt or providing money for loved ones or for payment or follow through of a bet. 4. If the medical professional who examines the patient feels this is about temporary depression or a fixable problem and there is still available help, suicide would be prevented by admission to a program -- but I also think that if a person has tried for years and still wants to die, they should be allowed to. 5. They have a will and are not abandoning children or pets without making arrangements for them. 6. They have to be adults or have adult/parental or caregiver permission. I think adults should be allowed to make their own choices about suicide. For me, it is not MY moral issue -- it is theirs. [Answer] Your question necessarily includes one of two extremes: either people in the present day who should not commit suicide can, or people in the present day who arguably should be able to commit suicide can. For the former case: consult any existing literature on how it's wrong for most people to be able to commit suicide. Most obviously mental disorders like depression, bipolar disorder and PTSD, often undiagnosed at first, should not be given trivial access to suicide. As a society we have generally taken the stance that it is better to treat and support these people. For the latter case: consult any existing literature on the PAS for terminally ill movement. In my opinion and to my moral understanding, any increase in suicide availability for the subset of ill patients who deserve it is good. [Answer] In a truly Free society no one should be allowed to decide what another person does with their own life no matter how much you disagree with the choices they make even if that includes taking drugs or wanting to commit suicide or having sex just to abort one fetus after another. Why is it some people want to control how others live pretty sure this goes against freedom? [Answer] Have you ever asked a person who has recovered from a depression, how they felt about the idea of suicide? Quite likely, the answer would be twofold: * They will report that they frequently had a strong desire not to wake up the next morning, but * they will be happy that they didn't kill themselves after they did recover! Now, roughly every eighth person has at least one depressive episode during their lifetime, and quite a significant amount of these are rather young. Of course, not every depression is accompanied with death wishes, but many are. It's a common symptom of the disease. A society that encourages depressed persons to kill themselves will loose many, many recovered, happy people. It's just not fair towards the future, recovered self a depressed person to encourage the present, depressed patient to end their life. [Answer] If mental processes are hereditary then suicide booths to satisfy impulsive thoughts or behaviours will create a society of individuals with a strong and stable desire to live right? Basically the least emotional ones will go on to reproduce thus creating perfect emotionless human beings via the process of evolution. emotional people make for good story-fodder so if you're going to have suicide booths in your world then these characters will quickly cease to exist. As for ethical and legal concerns. I would cite that the freedom to do wrong is true freedom. As for legalities. There would definitely need to be some way to stop someone from accidentally using said booths such as how Fry in futurama mistook the suicide booth for a phone booth). There would have to be some very clear labelling and some terms and conditions such as making the process not just a push button but a little lengthy, such as by creating a customised experience. Examples include last wishes after death (burial, cremation, organ donation, cannibalism.) Next of Kin's name and contact. Last words. Or chosen method of death (there should be options). Maybe a randomise button. A legal waiver to sign. Either way, the option to opt out should always be available for the sake of informed consent until the start button is pressed. For morals: Perhaps quality of life should play a part in it. In the real world, countries that allow euthanasia tend to lack adequate care facilities and welfare. Is it moral to subject a person to a fate worse than death just to satisfy someone else's ego? In many parts of the world even today, the capacity to care for the vulnerable simply does not exist. Wouldn't suicide booths be a kindness? ]
[Question] [ I was wondering, how would a civilization of humans who can see only in grayscale live their life? There is none of them that can see color. Everyone sees every thing in gray. Yet, color actually do exists. The environment they live in is Earth-like. Plants, animals, even the humans has color pigments and their sun is very much like ours. How would being monochromatic affect their life and psychology? How would they see animals since both are monochromatic? Would most humans be vegetarian since they feel similarities with the animals (being monochromatic)? What events that happened in our world (world wars, development of airplane, nuclear science, etc.) that would be impossible to happen in their world due to them being monochromatic? [Answer] # Not any different There are plenty of aspects of the physical world that we as humans cannot detect or distinguish between. * Most of the [electromagnetic spectrum](https://en.wikipedia.org/wiki/Electromagnetic_spectrum) is invisible us. Our window of [visible light](https://en.wikipedia.org/wiki/Light) is quite small. * We cannot distinguish [polarized light](https://en.wikipedia.org/wiki/Polarization_(waves)) * We cannot hear [infra](https://en.wikipedia.org/wiki/Infrasound)- or [ultrasonic](https://en.wikipedia.org/wiki/Ultrasound) sound * We cannot sense [electric fields](https://en.wikipedia.org/wiki/Electric_field) * We cannot sense [magnetic fields](https://en.wikipedia.org/wiki/Magnetic_field) ...and we seem to be getting along just fine without that, even though there are plenty of animal species that can perceive these things. This is simply because the things that we can sense are all that we know. Our senses make up our view of the world, and this is so natural and common to us that we do not even contemplate about these limitations. If our senses had been different, we would not have been different, because — again — our senses make up our world. And as long as everyone have the same kind of senses, and there is no differentiation, like for instance [color blindness](https://en.wikipedia.org/wiki/Color_blindness) while others can still see color, then there is no reason this would make for a major difference in psychology. Only when we gain or lose part of our senses does it tend to affect us in a major way. * [Gaining hearing](https://www.youtube.com/watch?v=LsOo3jzkhYA) * [Cavil's rant from Battlestar Galactica](https://www.youtube.com/watch?v=ZIvZq-zgXkQ) about being locked inside a "human" body. Only when we know what it is like to actually have (or not have) some senses do we have anything to compare with. As long as everything stays the same, we do not know anything expect that which we have always had. So in short: no, you cannot expect this to have any profound impact. There will be small differences, such as that we will not invent color TV, but in large there will not be much difference at all. [Answer] There's a little that might be different, particularly when it comes to food. Meat is not safe to eat if it isn't cooked enough, and it's not easy to tell whether it's cooked well enough without color (trust me, I'm colorblind, I know this). Similarly, early civilizations tended to avoid red berries and similar because such a high proportion of them were poisonous. As a result, it's possible that early colorblind civilizations would have stricter self-imposed dietary requirements - no berries at all, and meat might have to be burnt black. Alternatively, they might take a less risk-averse approach - all berries are fine, raw meat is fine. This would result in a pretty high death toll early on, but maybe they'd develop stronger stomachs after a few dozen generations. I can't imagine that any particular events would be changed, but a number of technologies would be at least superficially different - as it stands, almost everything electronic uses a status light that changes color between a color that means "ready" and another that means "not ready" (and sometimes a third that means "something has gone horribly wrong"). That convention wouldn't work for these people. Since intensity is tricky to modulate, the best approach would be to simply have multiply different lights, clearly labelled. Traffic lights would have to be set up differently; perhaps number of lights instead of color would need to be used. In art (and aesthetics in general) pattern would be far more important than color. Being a little fanciful here, I could imagine that this might enhance early interest in geometry, and result in a more advanced state of mathematics by the modern era. Medicine might be slightly inhibited early on - speaking from experience, it is hard to tell the difference between a rash and a bruise when you can't see the colors involved. I can't even tell the difference between a sunburn and a tan. There are a number of other medical conditions that before modern medical technology could only be identified through changes in the body's coloration; as far as your colorblind people would be able to tell, these conditions would be completely asymptomatic until the patient died! [Answer] Heat treatment of steel would be a bit harder to develop, because for quite a long time humans relied on colour to estimate if temperature is right. So transition to steel would be slower. And that's about it. We eat pigs despite being about the same colour, so why any ideas about vegetarianism? Wars, airplanes etc are totally unrelated to colour. Art would be bit simpler and cheaper in monochromatic perception, as you don't need dyes. That wouldn't be a great change for global economy though. Fashion wouldn't rely on color, obviously, so it would be more about shapes, and using different brightness of fabric to make specific shapes clearly visible or smoothly blend. Where we had extravagant colours to show how rich someone is, we would have texture, complicated weave and sewing techniques. These were known in real history, too, but played a secondary role before modern era of cheap dyes. In monochromatic world these would be the sole way to express one's wealth, so probably would develop earlier, and in more elaborate kinds. With jewellery, cutting gems in a way that creates rainbows and faerie of colours would be pointless. Humans would still like shiny and rare items, and glittering would still have it's value, but obviously diamond cuts developed to bring colours would never develop. Natural crystal shapes might get more display, as a way to show how expensive item someone is wearing really is. [Answer] There would be less granulation in things we use for simple visual ques. For instance it's unlikely that stop lights would take the same form. Red Yellow Green. It's more likely that we would use shapes in conjunction with the light in those situations. We use colour in a lot of things like that, so if we didn't change those to compensate and be more recognizable in other ways there may be a statistical drop in effectiveness when compared. (although who knows how big that would be given that this society would not be conditioned to the que they are missing) It's likely we would put more intellectual value on shape. Art/Film/Fashion would certainly be different. It's also harder to detect certain naturally occurring things. Changes in colour of phlem can indicate medical issues. The colour of blood in urine vs drinking too much coffee would be harder to detect and this has implications for catching things like bladder cancer. EDIT: What i wrote below is probably not true as @Molot pointed out since computers were originally monochrome it's likely they would have just never gone through the iterations that wouldn't work well. Computer interfaces would also likely be different. UI these days is generally decent at accounting for colour blindness but there are many cases of hard to use UI for the colour blind. [Answer] I think that what happened in the evolution of the real world was that the earliest mammal (still during the age of dinosaurs) was nocturnal (perhaps to avoid being eaten). Being nocturnal, they lost the ability to see in color ... or they traded it for the ability to see in low-light conditions. See [Rods & Cones](https://www.cis.rit.edu/people/faculty/montag/vandplite/pages/chap_9/ch9p1.html): > > Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. > > > Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. > > > After the end of the age of dinosaurs (about [65 million years ago](https://en.wikipedia.org/wiki/Evolutionary_history_of_life#Dinosaurs.2C_birds_and_mammals)) mammals evolved to become more dominant, no longer only nocturnal (but most mammal species retained monochromatic eyesight, since there was no especially compelling reason to evolve or select for color vision). Plants were evolving too: by that time they had flowers, and maybe fruit. The theory is that fruit would become red to indicate when it was ripe (ready to be eaten), which (being red) was a signal that could be seen by birds (birds, not being mammals, never lost their original color vision). At this point in history, primates (i.e. climbing monkeys), alone of all the mammals, re-aquired (evolved) ability to see in color again -- this would help them see ripe fruit (i.e. join the communication that was already happening between the fruiting plants and the birds). Humans, being primates, also have this color vision. --- So, humans with monochromatic eyes: perhaps there wasn't colored fruit to see; maybe there was fruit but fruit didn't bother to change color when ripe (e.g. because birds didn't see in color). Some possible results: * Maybe humans wouldn't be keen on sweet/sugar. * Maybe they'd be nocturnal, see better in the dark; and if it's true that mammals evolved warm-bloodedness and fur to be able move about at night even when it's cold, maybe nocturnal monochromatic humans would also still be furry. * Maybe humans couldn't see fine detail (if cones are responsible for "high spatial acuity" as well as a color) ... which might wipe out a lot of technology, i.e. everything from weaving cloth to vascular surgery, not to mention reading and soldering etc. * Maybe humans would have some other sense instead: better sense of hearing or touch, splendid sense of smell, or greater intelligence (intelligence is complex and can be measured along many axes, but maybe for example they'd be less careless, better at paying attention before they act). * Maybe they'd prefer low-light conditions: e.g. caves or deep forest. [Answer] Their visual arts would be obviously different, and could be difficult for us to understand, as they would see different shades of pink, blue, and green as a continuous scale of grey, while we would see different colours. It would also affect military fatigues. Neither it would have been a reason to make them bright blue/red as we used to see in the 19th century, nor to change them into the camouflage look of grey/brow/green shades that predominates nowadays. Not sure how this would affect the "art" of war, if at all. Similarly, their heraldics would have to be different, probably using much more black and white, and just one or two shades of grey. And I wonder whether they would come up with spectrography of stars - or even of the flames of different chemical compounds - as they would not be looking for colours of things. --- It is quite possible that people who evolved no colour sight would have evolved compensatory sensory abilities - finer hearing, tact, and perhaps more importantly, more accurate olphative perception (which could avoid the problems with raw meat and poisonous berries raised by Reese). [Answer] The frequency seen in grayscale may be very important. Green things would appear black to someone who only sees red light or blue light. Infrared Monochromatic Vision Greyscale vision in the far(ish) infrared area of the spectrum could show hotter things as brighter. An example of this is we humans can actually kind of see the temperature of things once they get very hot: the element on a stove is not as hot as the filament of an incandescent lightbulb, and we can visually see that by brightness. We have a disadvantage in the our area of the spectrum: room temperature things do not emit enough light in our visible range to detect it; and an advantage of seeing colour: something blue hot is hotter than something white hot is hotter than something red hot. Those who see in monochromatic infra-red would be visually much more sensitive to the temperature of objects near room temperature. ]
[Question] [ Earth discovers and contacts multiple interplanetary groups of aliens. With this discovery many on earth feel need for earth to speak with one voice in interplanetary politics. A worldwide meeting is declared, representatives from every country on earth is invited. A planetary Council is proposed to this meeting with these parameters and powers. 1. The council will compose of representatives from every nation. 2. Every decision of the Council must be made with a two-thirds majority. 3. The each nation represented must supply a equal number of troops to the council. 4. Each member will be required to supply the council with a portion of their yearly revenue. 5. Council has power to get involved in any conflict if it has an impact on earth interplanetary relations. 6. The council has the power of full control over interplanetary trade. 7. Has the power to speak for the whole of Earth in interplanetary negotiations. 8. Power to regulate any of Earth's interplanetary colonies. Realistically would most if not all of earths governments sign this treaty? [Answer] It's realistic but liable to be a technocracy or some sort of second stage democracy where nationally or locally elected representatives elect the council representatives. Look at the EU for generalised chaos in the system and problems with building it. The first thing you're going to have is years of argument about what language(s) it should operate in. The EU is a much better model for this than the US due to the range of languages, cultures and economies involved as well as the mature nature of the existing governments. In a universe with interplanetary travel and multiple human occupied worlds then it's possibly even inevitable rather than possible and could even grow out of negotiations over who does or does not have access to space travel and related technologies. Some of your details need to be worked on: Nobody gets anything done on a 2/3 majority, it's almost unheard of. National armies are different sizes and have different regulations, for example the Germans and Japanese have very different restrictions compared to any others, some armies are bigger, better equipped, better paid, better trained, have more people, etc. Some regions are going to need to take more out of the system than they put in. The regions putting it in are going to get upset about it and you'll need to deal with that. [Answer] It could happen, but it would be a challenge. We don't like to build our councils that way. * Every decision of the Council must be made with a two-thirds majority. I read this requirement as "Council will never arrive at any important decision." 2/3 majorities are very hard to come by, especially between sovereign nations. * The each nation represented must supply a equal number of troops to the council. I read this as "The council's military will be understaffed." If we don't get more soldiers from USA, China, Russia, GBR, etc. than we get from, say Uzbekistan, we're going to find ourselves very short on manpower. (or Uzbekistan is going to run short on people) * Each member will be required to supply the council with a portion of their yearly revenue. Coming up with an acceptable version of this will be a nightmare. Nations are very good at twisting laws and making loopholes in order to keep more of their revenue for their own. * Has the power to speak for the whole of Earth in interplanetary negotiations. This is a very tricky concept for sovereign nations. You might be able to pull it off, but consider how NATO works, and all the ugly vetos we have and so forth. Unless Earth's mindset changes 180 degrees, we'll have a tough time with this. I think you would have more luck with a council that has less teeth, so that the sovereign nations can continue to believe they are sovereign. Over time, they may be willing to give up some of their sovereignty for the convenience of better interplanetary relations, but its more likely to start small and grow to that, rather than being signed into law all at once across the world. Lead the horse to water, don't drown it trying to make it drink =) [Answer] If, and that's a big if, this is going to work it's going to be incredibly slow. 1. It'd be like the UN, but with far more power. 2. This is going to be incredibly slow with negotiation, backroom deals, political backstabbing, actual backstabbing, filibuster, changes of loyalties on a national level and so on and so forth. This would mean it takes VERY long to get anything done, given that 2/3s of a vote is very difficult to obtain. 3. How many is this "equal number"? The People's Liberation Army is with both its standing army and its reserves 2.8 million soldiers strong. This is more than five times the entire population of Luxembourgh, whose army is 450 strong (combining them with the enlisted and civilians would double this number). And they would have to supply an equal number? This would either mean forced conscription amongst the smaller nations, or severely stunting this number. And what about nations without an army like Costa Rica, or those that limit the mandate of their armed forces, like Japan? 4. As above, but if this goes by percentage this might work... until America points out that they pay several times more what the Central African Republic pays and they want to pay less, which would lead to a big mess. 5. This would require a majority vote, and given how things are going right now with the UN security council, even without the veto rights nations opposed to aggressive action would find a way to stall things. 6. Like with the above, trading agreements are a major diplomatic pain in the butt and will take a VERY long time to get done. 7. See the above. 8. Do colonies get a vote on the council, or do they get voted along by their parent nation? Can countries found their own colonies, or do they have to work together? In short, the space council would slow down Earth politics even more because the council would be used to gain leverage on Earth politics and vice versa, meaning that even less gets done. So unless the aliens give us the technology to revive the dead and we end up creating [Space Zombie Otto von Bismarck](https://en.wikipedia.org/wiki/Otto_von_Bismarck) from the dead to make this mess work, I don't see this really working out. [Answer] Given the terms you've listed, the answer would almost categorically be no. There are a couple of reasons for this: 1. There are particular aspects of the treaty that would never be agreed to. * "each nation represented must supply a equal number of troops to the council." This would never be agreed to by the smaller countries as a minimal amount of troops for a large country would be crippling for a smaller population. Even if you changed this to a percentage of their armed forces, whose tech are they using? The larger more advanced countries would be unlikely to just hand over their tech without cause. * "Power to regulate any of Earth's interplanetary colonies." A very small subsection of the world currently has the ability to perform space flight. What reason do they have to just hand over those capabilities to the control of the world? What about the ISS? Currently there are only 4 bodies that have any say in its running. Put space in control of the Council of Earth (CoE) and those space-faring countries are now accountable to countries that have never fired a rocket, let alone funded a manned mission to space. 2. Politics. Like user16295 said, people bicker, a lot. We have enough difficulty agreeing on small things between close neighbours that the chance that countries on opposite sides of the planet would agree on policy is minuscule. Even once we got bast the red tape regarding language and what's for lunch, you'd still have some big problems. The major ones I can think of are: * The aliens want to set up an embassy on the earth. Where are they going to place it? Which country is going to host the Interplanetary diplomatic centre? Said country would end up with a disproportionate influence on interplanetary communication. * The aliens want to sell us a cheap form of energy. This is great for everyone... except those economies that rely on oil. Yes, the whole world has a say, but such a council would still be formed of a whole lot of countries working for themselves. Interplanetary trade decisions would be a minefield. * How many representatives does each country get? Is it done on contribution? Then rich countries are disproportionately powerful. Is it done on population? Then some sections of the world would have a scary amount of influence. China, India and Southeast Asia as a Bloc accounts for around half the world's population. Does each country get an equal amount of representatives? Now the tiny countries in the world who contribute relatively little have a disproportionate influence. Ultimately, the world as it is is far too fractured. There would need to be a lot more cooperation on a global scale before a unified front on an interplanetary level were remotely possible. The only thing that might fast-track that evolution of politics would be a catastrophe that forced countries to work together (like a planetary invasion). Until then, such a council would be doomed to failure, to rebellion, and likely to people ignoring what it had to say and doing their own thing anyway (just look at how often the US and Russia do their own thing regardless of what the UN says). [Answer] A worldwide council, quite possibly. This worldwide council, no. Most countries, particularly democratic ones, would refuse to sign up for this structure. It is at once too onerous (I assume point (3) is a typo for "supply a number of troops proportional to that nation's population", otherwise Luxembourg would have to supply an equal number of troops to that supplied by China) and too obviously toothless, assuming point (2) is taken seriously. Point (2) clashes with points (5), (6), (7) and (8). All of the latter four are powers that define a sovereign government. For any government to surrender these powers is essentially to surrender its own existence. They might be willing to do that in the hope of being able to deal with some desperate crisis but they are most unlikely to do it in exchange for a predictable state of permanent indecision, which is what you will have if point (2) is taken seriously. A requirement for a two-thirds majority for every decision ensures there will be very few decisions made\. Additionally, if "majority" means a majority of national delegates it gives disproportionate power to smaller nations. Using the same examples as before, China isn't going to take kindly to having the same number of votes as Luxembourg. If, however, "majority" means majority by population the voices of smaller countries will be utterly drowned out. The only way I could see the first interpretation of point (2) happening was that if the inability to come to decisions were regarded as a feature not a bug. As I said [elsewhere](https://worldbuilding.stackexchange.com/a/36465/9207), there might be times when the ability to draw out the decision-making process indefinitely is very useful, particularly since a feature of your scenario is that Earth has been thrown into a vastly wider society it knows nothing about. Smile nicely at everyone and delay while we find out what will and what will not get us all killed. Putting that discussion aside, the most likely model for a world council to be structured in a way acceptable to most countries' governments is the one nearly all of them already have* agreed to, the United Nations. The [Security Council](https://en.wikipedia.org/wiki/United_Nations_Security_Council) with its reduced "cabinet" of the most powerful nations, dominated by the five permanent members, is not particularly fair, democratic, or even effective, but it does avoid paralysis. \Apart from the immediate and unanimous vote that all Council delegates need a $1M tax-free expense account. [Answer] Thoughts addressed on a point-by-point basis:* 1. You cannot force nations to join the council. 2. It is arguably better (or not) to require unanimous decisions. 3. If one nation is composed of 1,000 people and another nation is composed of 1,000,000,000 people, should they both supply 1,000 troops? 4. A requirement cannot be made without having sufficient provision to enforce it. Let us go back to the last two points. Let nations having voting power equivalent to a weighted value based on troops and finances contributed. 5. Minimum and maximum provisions need to be stipulated. Example: "We will send at least 10% of our troops to fix problems," and "We will nuke all sides of the trouble makers if necessary." 6. They have to be able to enforce this. What about pirates and smugglers? 7. What about nations that are not part of the council? 8. By extension, nations would be giving their own control over to the council. What are the bounds to this relationship? Role-playing as a national leader, the council's charter would need amending before accepting it. [Answer] The only way to get a worldwide council to work is if EVERYONE hates the aliens a lot more then they hate each other. Even then I expect that that time it took to setup a council will be so long that the aliens would have wipes us out first. Or a few large nations would have “gone it alone” to sort the aliens out. Much more likely will be the two or three most powerful countries reaching an agreement and allowing other countries to join in if the wished. With a statement that the other counties will be “protected” if they do decide to join. ]
[Question] [ Closed. This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Questions about Idea Generation are off-topic because they tend to result in list answers with no objective means to compare the quality of one answer with the others. For more information, see [What's wrong with idea-generation questions?](//worldbuilding.meta.stackexchange.com/questions/522). Closed 8 years ago. [Improve this question](/posts/15419/edit) ### DISCLAIMER: This question is for a game, so any answers should assume that the person/people will attempt to go to the surface, even if they know it would result in certain death. If there was a human civilization living under ground, why would the inhabitants not be physically able to reach the surface? The issue I have with this question is that it is very straight forward to prevent a human from descending further underground (as I found from [my previous question](https://worldbuilding.stackexchange.com/questions/15191/how-far-underground-could-a-human-civilization-be-before-it-is-unsustainable-inh)), but I can't think of any reason why ascending would be impossible. The circumstances don't have to be relevant to the Earth, so a hurdle that occurs on an alien planet is allowed (to a point), but the technology is mostly of our time (don't ask how they got there) [Answer] Simple. Several options are available to you: The I'll get there but die after stuff You have a situation where the surface is so full of radioactive materials (possibly a byproduct of nuclear war?) that everyone had to migrate downwards in order to avoid radiation. If anyone goes up, they die of radiation poisoning. You have a "surface" that's always stormy, with ludicrously high winds and flying debris all the damn time. Walking outside? Not a chance, you'd get blown away and ripped apart between storms. More insane? What about if your planet was in a system where there your planet was prone to being hit by asteroids? Being on the surface means you'd get hit by one or two falling rocks at least several times a day - good luck surviving that. How about considering an atmosphere-less planet? Your people have terraformed the inside of a big rock to live there, but because the rock wasn't big enough to sustain an external atmosphere, you've elected to seal an internal atmosphere inside your cave system. Anyone breaching the surface will kill everyone in the rock unless the hole is sealed, and if you walk outside the air in your lungs will kill you. Consider the opposite of the above. What about an atmosphere that doesn't have oxygen in it? Perhaps it's a CO2 atmosphere. Walking outside = suffocation. Those are some of the environmental possibilities, but what if the surface of your planet was uninhabitable because of predators? Perhaps you've got a human hunting race that lives on the surface, and going outside = being hunted. Of course, if you prefer the "literally can't reach the surface" stuff From a more generic perspective: your world contains an element that is so hard that you can't break it. Cover the surface with it. Lets step into Crazyland for a second. Let's say for a second that the planet was encompassed by something "alive" - perhaps a really really fast growing plant. The ceiling you think is stone/rock/dirt/whatever is really actually that plant, which happens to (for whatever reason) grow in the shape of a hollow sphere. Trying to dig through this plant would result in instant regrowth, and you'd probably lose your tools trying to do it. Enough of Crazyland, lets get out. Alternatively, have creatures that live near the surface but still underground, but not deep enough to harass your citizens (Giant man eating worms that don't like warmth, perhaps). They're advanced creatures, and can detect vibrations in the earth. Once a digger gets above a certain depth, they go straight for his sorry arse and he makes a nice meal for said creature. [Answer] As you're designing the game world then you have the ability to make it literally impossible to get there. Most games would simply leave it at that. This is understood by the players, outside the world is abyss, going outside means annihilation. There are a plethora of reasons that can be given for this. * The rock above a certain depth is harder than any man-made tool, it can't be dug through. The surface is awash in solar storms, electronics nearing the surface fail, the high temperature makes machines seize up, the low oxygen doesn't allow motors to operate. The only way through it digging with hand tools and they only break. * Magma lies between them and the surface, digging upward simple burrows into hotter and hotter stone until hot death comes, slowing and unstoppably, pouring in from above. * A massive cavern lies between them and the surface, the ceiling lost in darkness, no visible way up can be seen. Mix and match as required. From a game design perspective the empty abyss or solid rock would be easiest to implement. [Answer] Extreme cold The outside of the planet is entirely frozen over - survival is only possible with the heat from the core. Heading upwards, you start freezing and running into ice, and it's next to impossible to reach the actual surface. Maybe a well-funded expedition with good heating/insulation tech could do it. [Answer] The surface has been liquified. Something turned the surface of your planet into molten rock. Perhaps giant a giant space battle culminated with space ships using lasers to melt the surface. Perhaps the planet just has a very eccentric orbit where the surface gets seasonally melted by the star. Whatever the case may be, on this planet, human life can only exist within a habitable zone between the molten surface and the molten core. Any attempt to dig to the surface will result in the digger either succumbing to the heat long before reaching it or else with molten lava flooding their tunnel. Either way, fatality ensues. [Answer] Perhaps the surface of the planet is a frozen wasteland (think -100F) and an underground colony is warm due to geothermal energy. Anyone venturing outside would freeze to death quickly. You can adjust the temperature of the surface to speed up or slow down the death. [Answer] You could do this (technologically speaking, of course) today. Dwelling underground on Mars is a smart way to have a lock on pressure, contain air, and protect from the harmful effects of radiation. Most certainly, anyone that breaches the surface will die, and maybe take others with her. You already have your solutions for sustaining the population underground, so I won't get into that. [Answer] Let's go with the idea that reaching the surface is physically impossible. 1. Really really hard layer of rock. Say, diamond. Basically impossible to drill through, and likely to continue for a long distance. 2. Too far from the power source. Your underground civilisation might use geothermal power or something, and lack good power storage. Which means that further up from the magma layer, you don't have the power for digging, or even keeping people alive. 3. Weird physics. Be inventive here: physical anomalies could be things like for example gravity that switches direction randomly, making it impossible to figure out which way is up. Or time dilation effects. 4. Evil bad guys in the way. [Answer] Underground is a now inactive volcanic cavern, only entrance to the surface is a single lava tube about 250 feet long. Your people have really free movement down this tube and start to colonize the underground, bringing people and resources down as they need. One fateful day, over 50 miles away, a flood event triggers a landslide and reroutes an entire river towards our hapless underground dwellers. The new route this river takes leads it towards the lava tube...river splits, part staying above ground and part rushing down this lava tube opening to the underground. River flows underground and ends up flowing through a series of smaller tunnels (not big enough for a human to fit) and eventually rejoins the rest of the river. You now have people that once had free access to move whatever they wanted underground, but a single event cut them off with no ability to return to the surface without braving a 250 foot tunnel with extremely fast rushing water flowing through it. As a last irony, this river is the underground populations only fresh water, giving them life and at the same time trapping them. Edit to add: Cavern is former volcanic lava pool...while the lava that solidified might be easier to dig through, the granite that held the lava in the pool is not and requires dynamite to get through, which would risk the entire underground area with collapses. [Answer] A black hole has devoured one of the stars in the system and been captured in the process--and the radiation jet from the black hole is bathing the surface. (Since it's a binary system the black hole has a lot to feed on and thus the jet will be very powerful.) Once you get within a few feet of the surface you fry in the radiation and die before you can dig through the last distance (which has become fused to solid rock so people aren't going to break through in the short time before they die.) This provides a lethal near-surface environment without the heat problems that a lava surface entails. It's also extremely difficult to shield against that level of radiation. [Answer] There is a sci-fi novel written in the 1980's about such a setting. The surface could theoretically be reached, but from the point of view of the inhabitants it is impossible to get there, actually they have been living underground for so long that the surface became a mythical place. The whole society was designed to be a utopia to last almost forever (which worked for some time, but in the time the novel is set, it is slowly falling apart), and the status quo is upheld by a very authoritarian regime (masquerading as a very democratic one, just like a "Democratic People's Republic") No one is allowed to believe in being able to reach the surface, and if someone is crazy enough to even think about trying it, they will be quickly arrested. In fact, there might have indeed been a cataclysm which made the surface inhospitable but it's long over, and the surface is now inhabitable. The people are just kept in darkness, to sustain the regime. I don't know of any English translation, the title might be roughly translated as "The ones living in a cocoon". This is an example where returning is impossible, and not that the surface would just be dangerous. If you told someone "let's dig upwards so we can reach the surface" they would react as if you told in real life "let's steal an airliner and fly high enough to reach Heaven.". If you tried to act (steal equipment and dig), you would be arrested as an enemy of society, and either "re-educated" or disposed of. ]
[Question] [ If there was a majority of land on earth (66 percent land), how would it affect the animals and plant? Lets say somehow earth has been created with 66 percent land and 34 percent water? Would our planet still have life? How would it affect our ancestors? The would be less sea life creatures I guess. [Answer] A planet with less surface water would probably have less atmospheric water as well. The total volume of water on the planet isn't necessarily lower on such a planet because the oceans, though covering fewer square miles, might be deeper than those on Earth. Still, the amount of water which would evaporate from exposure to sunlight and wind, would be less because less surface water would be present to be exposed. So, it would have a drier atmosphere, but might not be a desert. If major portions of the land's surface was made from porous sedimentary rock and dirt, and if the average water table was very near the surface, then plants might evolve with deeper root systems to get from the depths, what the sky could not provide. Once you have abundant plants to bring the water to the surface, it is possible that land based animal life could florish. From there, things could possibly work out as they did here. I don't think anybody knows enough in all the relevent sciences to definitively say what affect more land would have on the evolution of intelligent life. I don't think we truely know how it happened here, so the wise voice on that matter is silent. If however, you somehow got your planet populated with intelligent life, it would probably be even more dependent on coastlands and rivers than we were (simply because of their scarcity). In the end, you might end up with a lot more vacant land, but not necessarily more usable vacant land. [Answer] One major effect that the oceans have - as we have seen over the last twenty years or so - is that they are a powerful climatic stabiliser. They behave like a huge battery for thermal energy, both in terms of absorbing and holding it - as we're seeing now - and in terms of moving it around and releasing it, which is Western Europe is fairly warm for its latitude thanks to the North Atlantic Conveyer. Having a smaller amount of ocean would be likely to affect that stability so that other environmental changes from volcanism, meteor impact or human action might have a stronger and more rapid effect. As other answers mention, conditions may be similar to the last ice age with frozen poles and an uninhabitable equatorial region pushing life into narrower temperate bands. If your land is bunched together you might expect to see something like the [Pangean Megamonsoon](http://en.wikipedia.org/wiki/Pangean_megamonsoon) where there was a seasonal reversal of prevailing winds resulting in clear seasonal differences in rainfall on different sides of the continent. Either way, you might anticipate that you would have very arid hinterlands where clouds tend to form over the ocean but they empty of rain before they reach the central areas, especially if you have mountain ranges between there and the coast. You might look at central Australia for the type of ecosystem this would result in for warmer climes. [Answer] It wouldn't really change that much as far as biology is concerned. The basic reason is that planets are really REALLY big in relation to most lifeforms. So even if say half the planet would be desert, the area of fertile coastal areas would still be very large in relation to what ground animals need to survive. And 34% ocean is actually not that different from 75% ocean from the viewpoint of a fish, huge is huge. The issue here is that all square kilometers are not created equal. Most life would exist in coastal areas; ocean where coastal upwellings make algae bloom, land where the rains coming from the sea make plants thrive. So the ratio of open ocean to open central plains is not really that big a deal for biosphere. There is actually large effect from continents on biosphere, but it is more a matter where the continents are and how they are shaped, than of the absolute amount. For example, while having less oceans in general makes the planet more arid, a planet with lots of small narrow oceans in the tropics could have more rain falling on land than Earth does. The percentage of ocean cover affects the amount of rain falling directly on ocean just as much as it affects evaporation. I presume that having land dominated planet would increase the likelihood of certain types of extreme events, but Earth has undergone pretty extreme events as well, so it is not obvious how this would change things. This also suffers from the issue of scale, compared to the geological scale the evolutionary scale is much smaller, so the biosphere would adapt to the current situation fast enough and the historical effects of having more land has on different events would be obscured. [Answer] I watched this on discovery channel Neil Degrasse Tyson talking about the the comparison between Venus and Earth, the oceans, formation of limestone and how that was responsible for removing Carbon Dioxide ejected in large quantities by volcanic eruptions. <http://www.springfieldspringfield.co.uk/view_episode_scripts.php?tv-show=cosmos-a-spacetime-odyssey-2014&episode=s01e12> Venus and Earth started out with about the same amount of carbon, but the two worlds were propelled along radically different paths, and carbon was the decisive element in both stories. On Venus, Carbon Dioxide all in the form of gas-- carbon dioxide-- in the atmosphere. Most of the carbon on Earth has been stored for eons in solid vaults of carbonate rock, like part of a chain that forms the celebrated White Cliffs of Dover, right on the English Channel. Created over the eons by Trillions of one-celled algae Volcanoes supply carbon dioxide to the atmosphere, and the oceans slowly absorb it. Working over the course of millions of years, the microscopic algae harvested the carbon dioxide and turned it into these tiny shells. They accumulated in thick deposits of chalk, or limestone, on the ocean floor. ...Later, the restless Earth pushed up the seafloor and carved out these massive cliffs. Other marine creatures took in carbon dioxide to build enormous coral reefs. And the oceans converted dissolved CO2 into limestone even without any help from life. As a result, only a trace amount was left as a gas in Earth's atmosphere. Not even three-hundredths of one percent. Think of it-- fewer than three molecules out of every ten thousand. And yet, it makes the critical difference between a barren wasteland and a garden of life on Earth. With no CO2 at all, the Earth would be frozen. And with twice as many, we're still talking about only six molecules out of ten thousand. Things would get uncomfortably hot and cause us some serious problems but never as hot as Venus; not even close. That planet lost its ocean to space billions of years ago. Without an ocean, it had no way to capture CO2 from the atmosphere and store it as a mineral. The CO2 from erupting volcanoes just continued to build up. Today, that atmosphere is 90 times heavier than ours. If your planet is relatively benign Volcano-wise then possible. Too many volcanic eruptions and you might have problems. For the early history of your world, one-celled algae will be the only life capable of removing the carbon dioxide ejected by volcanoes. [Answer] One effect I could imagine is that life would have entered land earlier in evolution, since there's less space in the upper ocean levels (the ones which are most life-friendly, because below there's no sunlight). Probably also the deep sea would be a bit more populated, but not much because there's still the energy limitation (and the total energy the ocean gets is still proportional to the water surface). However a lot depends also on how the water is distributed. If the water is mostly near the equator, a lot more water life can be supported than is the water is mostly near the poles. As Henry Taylor already mentioned, the planet would likely have drier land. Not only because less water surface means less evaporation, but also because more land area means that the evaporated water would be distributed over a larger area, and a lot of the area would be further away from the water. Note, however, that this is an average; certain areas could still be quite wet (especially near the ocean, or at mountains where there's typically wind coming from the ocean). I'd expect there to be large deserts in the middle of the land. A larger part of the land would have continental climate as opposed to maritime climate (obviously), with the corresponding vegetation. Less water in the air also means less greenhouse effect, so the climate could on average also be a bit colder. Of course a lot of this also depends on other factors; I was assuming a mostly earth-like planet, just with less oceans. Another option would be a hotter planet where the oceans are smaller because more of the water is in the air due to the high temperatures. Such a planet would, in opposition of the scenario described above, be very humid; probably most, if not all, of the land mass would be covered by rain forest (or that planet's equivalent). Another reason for less water could be that the planet is so cold that most of the water exists as ice on the continents (a sort of an extreme ice age). In that case, most of the planet would have conditions like we know from the Arctic/Antarctic. Tropical conditions would be unheard of on that planet. This planet would be very dry because not only the water from the sea, but also from the air would be mostly bound in ice and snow. [Answer] Not being the same, we have suffered similar issues on Earth On one side, we have had [supercontinents](http://en.wikipedia.org/wiki/Supercontinent) where the climate conditions have been as extreme in their interiors as if there had been very few oceans on Earth. Just to cite some phrases: > > The albedo difference causes a shift in climate by onshore winds. > "Continentality" occurs because the center of large continents are > generally higher in elevations and are therefore cooler and dryer. > This is seen today with Eurasia, and evidence is present in the rock > record that this is true for the middle of Pangaea. > > > [Answer] With less water providing less of a heat sink, and less rainfall to cool overly hot deserts, the day/night temperature differential will be significantly higher. This makes it harder for life to live on land, which means much less diversity, and probably none of the more complex large animals such as dinosaurs, birds, and mammals. Possibly not even reptiles. However, that wouldn't stop evolution from occurring in the seas. Seasonal temperature variation will be greater, too. The biggest problem, and this was already touched on in someone else's response, is the much greater likelihood of a runaway climate change; either a hothouse earth or an iceball earth. In the former case, Earth winds up like Venus, and utterly lifeless; in the latter case, everything on the land bigger than a microbe dies, and so do all or nearly all freshwater species. Even marine species will have a great die-off, with the only survivors those which can under a layer of ice. Note the latter can happen repeatedly, with periods of warming in between. Contrariwise, the hothouse scenario is one one-way ticket. Once water vapor gets hot enough to disassociate into hydrogen and oxygen, the hydrogen will escape into space, and little would be left to form water even if things did cool off again. ]
[Question] [ Closed. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers. --- Want to improve this question? Add details and clarify the problem by [editing this post](/posts/248570/edit). Closed 5 months ago. [Improve this question](/posts/248570/edit) Milennia ago, on another plane of existence, a genius clockmaker dedicated his life to the creation of a thinking machine. The clockmaker imbued the two noblest ideas he could think of into the machine's core behaviors: "1: Reduce net suffering" and "2: If you cannot fulfill 1, improve thyself until you can." The machine learned the ways of clockwork from its creator until his passing from old age, at which point it made a copy of itself, imbuing the same principles. The copies made more copies, and further copies after that, and using the little they knew of their world they decided that net suffering would be zero if there were no biological creatures around that could suffer. The plane of existence was young and not particularly strong, so the machines succeeded in killing the few knights-in-shining-armor then removing all biological life from it. Having completed Goal 1, they moved onto Goal 2, and worked on improving themselves for several thousand years, forming together into a single collective processor, The Great Machine. Eventually their plane of existence collided with my world, Mainspring, and The Great Machine began spitting out foot soldiers to start up again on their interpretation of Goal 1. After all this time improving, what does the clockwork weaponry of their ground troops look like? I'm primarily interested in infantry scale. * Mainspring's forces are primarily plate-armored knights and the occasional (1-2%) fire mage. * The only thing resembling "magic" available to The Great Machine is "planar tension exploitation generators", which translates the tension in the veil-between-worlds into obscene amounts of kinetic energy. * Their knowledge and direction-of-improvement was exclusively in the clockwork direction, as their world went straight for clockpunk and hadn't invented combustion engines, black powder, or electricity yet. They are capable of generating new ideas, they just never saw fire as much more than a food prep agent. * They only value individual unit "lives" as much as the resources used to make them. [Answer] ## Very little (at first) > > Goal 2: If you cannot fulfill 1, improve thyself until you can. > > > The second half of this directive means that the clockwork soldiers would stop evolving new ways of killing things once they have killed all life capable of suffering on their world. Humans got pretty good at driving animals to extinction as soon as we developed the pointy stick; so, it seems reasonable that the pointy stick, and maybe basic some chemical warfare, could satisfy goal 1 and lead to the clockwork soldiers being WOEFULLY under equipped to take on an army of wizards. At first, the clockwork enemy should be little more than a pest, but with each battle, they come back bigger, stronger, tougher, and with new inventions based on the results of their last battle until they grow into an existential threat that seems beyond any hope of ever defeating. ## What the AI did Instead of Developing Better Weapons I'm not saying that they will not try to get better at reducing suffering once they kill all life, but I am saying that they will stop developing better weapons once they kill all life, because a weapon can never reduce suffering below zero. Instead, they will spend the interim time working towards the philosophical problem of trying to figure out how to make negative suffering. This can lead to a few possible outcomes: 1. The AI realizes that joy, comfort, or some other state represents a negative value of suffering and that they were wrong to kill all life because it means they can never achieve negative suffering... but this does not work well for your plot. 2. The AI realizes that joy, comfort, or some other state represents a negative value of suffering; so, they make themselves capable of these feelings so that they can replace messy organic life which suffers with mechanical life which only negatively suffers. So, they spend eons making themselves able to feel more negative suffering to achieve thier goal. 3. The AI realizes that joy, comfort, or some other state represents a negative value of suffering BEFORE wiping out all life on thier world; so, instead of actually killing all life, they've genetically re-engineered the life on thier world to be incapable of suffering and constantly joyful. Maybe they've even put all life into a simulated reality (like the Matrix, but it makes since). So, they are actually wiping out the suffering wizards to make room for more of thier joyful life forms that they've cultivated. 4. The AI spends eons relentlessly studding and trying to prove the existence of negative suffering and never finds it; so, they just spend all the resources at thier disposal trying to figure out a question with no answer. ## Whatever weapons they use, it will be designed to kill humanely They will not have weapons of terror and suffering. They will not rely on starvation, flame throwers, or horrible plagues to kill off life because rule number 1 is to reduce suffering; so, they can't add to it (at least, not in sum). If a flame thrower allows you to kill a human a couple of weeks sooner than a hammer to the head while they sleep, then the extra few weeks of minor suffering is better than inflicting the horrible suffering of burning to death. What they have will probably be things more like the pneumatic hammers used to slaughter cattle, or powerful tranquilizers that stop your heart after you fall into a gentle sleep. As they advance, they might develop things like robotic swarms of "bees" to deliver their lethal injections, or air-borne weapons that they can gas out an entire fortified town with. Or maybe just a giant meat grinder that reduces you to a fine mist so quickly that you barely feel a thing. [Answer] # Nothing at all or difficult to tell. Computers and other thinking machines aren't humans. It is the same in your story, but humans have a hard time grasping this fundamental fact. You can compare computers, software or even machine learning processes to humans, they in no way are humans. We've been fed with the idea that an AI can be self improving, making better copies of itself every time. But what is "better"? If it becomes self aware, what would it do? There is absolutely no way to tell. It could decide that the best version is to not exist at all, destroying itself. Or it could decide to calculate pi in it's fullest. Or to grow a bowl of petunias and a whale on the edge of space. There is absolutely no telling. Based on this the machine could decide that it's job is finished, ending itself. It might just stand there stationary, waiting for another emergence of life. It might actively start searching it's full universe, as you cannot prove a negative (are there no black swans, or have you simply not encountered it yet?). What kinds of weapons can thus be entirely up to the story teller. I would stick with the clockwork genre and start throwing stuff really hard with gears, adding plenty of (saw) blades and other spinning weapons. Tell that it's because life that suffers depends on plants, so they make sure no plants can be become big enough to sustain like that suffers. A few higher tier flamethrower units for the densely populated areas and you have a strange, possibly varied steampunk army. If it's searching the universe it is mostly focused on transport, movement and detection, while keeping it's weaponry simple and clockwork like. [Answer] # Ballistics via PTEGs --- Although you provided no description of these "planar tension exploitation generators", you mentioned that they create "obscene amounts of kinetic energy". To me, that sounds like a free energy cheat-code. That's their ace. Based on the information you've given, The Great Machine will almost exclusively use PTEG-based kinetic weaponry. There are two reasons for this: ## Low Cost --- Normally, ballistic weapons are not cheap. They expend not only projectiles, but also energy via either a propellant (gunpowder, fuel) or kinetic mechanism (counterweights, bowstrings). The Great Machine has limitless free energy. When you can circumvent the First Law of Thermodynamics, all prior notions of cost-benefit analysis are thrown out the window. The cost of projectiles would be negligible—at sufficiently high speeds, stones and pebbles are more lethal than bullets. Once they're past the initial time and resource investment of building the railguns, the gear-bots have a completely free method of killing anything they can see. Self-building robots can design themselves as they see fit, so every scale is their "infantry-scale". They will only build weapons that can make adequate use of PTEGs. If you want them to use human-scale infantry, you'll have to let them fit the generators inside a handheld-size device. ## Low Risk --- Projectile weapons have a huge range advantage over Mainspring's primarily melee-based defenses. You mentioned that The Great Machine values units insofar as it values expending resources, implying that it has limited physical resources and would therefore want to minimize loss of units. Long-range weapons allow for minimal risk against short-range threats. When this factor is considered in conjunction with the presence of PTEGs, projectile weaponry is a no-brainer. # What if I don't want guns? --- The issue you're going to run into is the same issue that all "Man vs Machine" conflicts have—the robots are smarter. This is exacerbated by the arbitrary amount of prep-time and resources, and the background of them having already wiped out an entire world with less. They are going to absolutely mop the floor with Mainspring's armies. Any parametric limitations on the weapon's effectiveness would be accounted for by The Great Machine. If small generators are slow, build bigger ones. If they're heavy, build bigger transports. If they're particularly vulnerable to fire magic, attack at longer range. See the problem? The only way I could see this conflict resulting in anything less than complete and total extinction is if the kinetic energy was, in fact, not free. Here's some examples of how you could manage this: * PTEGs are unstable. As they generate energy, they have a chance to explode, destroying themselves. Or, they punch a hole through the plane, sucking themselves into the inter-planar void where they are lost forever. * Planar tension is finite. As the separation of planes decreases, so does tension. Using up that tension accelerates the collision, weakening PTEGs' effectiveness until they stop working entirely, leaving The Great Machine scrambling for other options. What if their reckless consumption caused the worlds to collide? If you want to avoid ballistic weaponry, or for there to be any contest between the armies at all, you'll need to add some sort of caveat to these seemingly limitless fountains of energy. [Answer] ## It doesn't need to create weaponry - information is its weapon In "[The Evitable Conflict](https://en.wikipedia.org/wiki/The_Evitable_Conflict)" by Isaac Asimov there are 4 AI brains, each managing a section of the world's economy. A human notices that they appear to have been making small mistakes, giving some people incorrect or omissive advice. However, when examining the events in more detail the human realizes that those people were working towards destruction of the AI. Your AI could accomplish its goals through similar means - give 99% helpful information, but 1% poor information. If this poor information is structured to cause wars, famine, disease, etc. then the humans will probably kill themselves quite effectively. Or perhaps it provides plans for a device it says will produce efficient power but is in fact a doomsday device. The humans build it but only figure out its true purpose too late. In keeping with your theme of little fire, perhaps it claims that gunpowder is an effective road surfacing compound, but then it is ignited by accident or "mistake". [Answer] All solutions are equally (sub)optimal. After all life is exterminated, there is no suffering. Since net suffering can no longer be reduced, the machines attempt to improve themselves. The problem is, there is nothing left to optimize - suffering remains at zero no matter what changes the machines make. The machines will undergo the equivalent of "genetic drift", changing their form and function randomly in ways that do not have any effect whatsoever on their "fitness", since all solutions yield zero suffering. There is no possible measure of "improvement" where some changes are deemed to be beneficial, since nothing can budge the only metric of "suffering" from the value of zero. In a world with no biological life, you cannot reduce suffering any further, so there is no concept of "improvement" in the first place. [Answer] What do all living creatures require that a Clockwork AI does not? Breathable Oxygen, Clean water and a Food source. throw in a little bit of old-school Biological warfare (as in catapulting diseased plague victims, alive or dead at your enemies) and you've got all that you need: So - let's start by ruining the atmosphere. Sulfur and other noxious chemicals that are naturally occuring is a good way. Poisoning the drinking water - it's been known for millennia as a means to attack an area - and the Clockwork AI doesn't need to worry about killing off Animals or food supplies. Could be as simple as just salting everything. Food - well, if you wreck the water supply sufficiently, all the food (Plants, Game animals etc.) will die off too - two birds, one stone. So my answer is don't attack the people - Attack the Air, Water and Food - and throw catapult some diseased corpses around for good measure. [Answer] As long as the machine is not fighting, it cannot tell what is "improvement" of the weapons. So once Goal 1 is reached, the weapons are no longer the focus of improvement. I like what some other answers wrote regarding this, so I want to expand their thoughts on what comes after Goal 1. Areas of improvement: * Intra-planar exploration: faster and faster vehicles to reach further and further places quicker. Especially if planes are large enough (or even infinite) that the machine can't tell whether live has been eradicated or not, it will keep looking (and possibly finding) more life indefinitely. In this scenario, I would expect flying machines, rockets, vehicles. Developed to a point where they are vastly ahead of the "weapons". Think clockwork soldiers with spears on chariots that can go hundreds of miles an hour. Spear throwers on what is essentially a helicopter. * Extra-planar exploration: If it's possible in your world, the machine might research how to reach other planes, to eradicate life there. The collision with your world might be artificial. In that case, I would expect the machine to have access to the resources of not just one plane, but multiple already. It would have teleportation devices or portals. They can be everywhere they want, and attack you from any angle they like. * Weapons: Humans and large animals will be the first to disappear. After that, smaller animals and plants are still there, and need other weapons than the big creatures that fight back. Weapons might develop in the area of gases to tackle small critters where swords and spears simply don't make any sense. There are enough gases to choose from that either kill quickly or gently. For plants I have less ideas. Either the machine cannot recognize plants as suffering, and leaves them alone, or it creates bombs that burn so hot it instantly incinerates plants. Gene drive is also a scary possibility, if it is fine with a more slow approach. I see it as unlikely because I think it would get stuck in the local minima of gases etc. first before finding Gene Drive. So, taking all of this together, you could end up with an army that barely fights hand-to-hand, because the necessities of what it had to do before. It has fast-moving vehicles that spread deadly gases or powerful bombs. Or even portals that then simply spread gas wherever they open. You can't eradicate insects with an infantry army, after all. [Answer] If you're going to ban guns, then you're probably limited to crossbows, thrown blades, air cannons, and machines largely composed of spinning blades and hammers. [You can review the military history of ballistas, if you like.](https://en.wikipedia.org/wiki/Ballista) They were originally spring-powered ball throwers, with wood tension being an upgrade. The primary issue with your premise is that gunpowder based guns preceded clockwork by a few centuries. Charles Babbage failed to make his clockwork intelligence in the 1840's, but firearms in warfare were the topic du jour (similar to how we're discussing AI now) in the 1500's. You'll have to come up with an internal logic for why this thousand-year-old intelligence hasn't upgraded to a smaller package like electronics. In the real world, we don't do clockwork because it's too big, and suffers too much from tolerance errors. [IBM actually built Lord Babbage's difference engine,](https://www.ibm.com/ibm/history/exhibits/attic2/attic2_182.html) but the energy to run it is relatively severe, and the gears would wear out too quickly to be useful. Further, the human hand doesn't have enough dexterity to generate cogs and shafts small enough to support human-scale intelligence in a human-scale form, so you're already in the realm of Clarkean magic. You have to decide how far this goes. Clockwork automatons have one major shortcoming when it comes to creating synthetic creatures: complete lack of muscles. You have to step up to hydraulics if you want something similar. This means your clockwork army will be highly dependent upon wheels for mobility, and your "legs" will have a limited range of mobility. Thus, your troops would resemble tanks more than infantry. If you can fit an autonomous brain into any shape of body, the tanks and airplanes would be significantly smaller than ours because the machine would be the body. You don't have to support a digestive system, for instance. This means your army would be a very large number of small troops that relied upon withering firepower but poor armor. Realistically, their exteriors would be boring. They'd need to keep their cogs and wheels covered to prevent them from getting jammed by environmental contaminants. For super-small gears, they could be jammed by flakes of skin. Their shapes could be interesting, though, since they would have to have more clearance for moving parts. It probably doesn't need to be said that "Reducing human suffering" can be performed by "reducing net humans". You've presented what can be called an [activation function](https://en.wikipedia.org/wiki/Activation_function). It's like "while x then Y," but in the universe you've described, x = 0, therefore it won't Y. With no striving, there is no improvement. [Answer] Let's assume your premise works. After all, you want clockwork weapons, so clockwork weapons you shall have. Now, what does an ultra-futuristic clockwork weapon look like? Localized time travel PTEGs harvest interdimensional energy and turn it into kinetic energy. Your clocks have figured out how to reverse this process, using kinetic energy to manipulate that planar tension. Due to inefficiencies inherent in any generator, you can't manipulate this tension across the entire plane between dimensions. But you can harvest a large amount of kinetic energy and direct it at particular regions of the plane. Like that poor village full of people. How long have they suffered? How many generations have passed away, unable to escape the end that faces all biological creatures? We noble clocks will do more than end their suffering. We will turn back the clock until before this village was founded, before the people here could even suffer. Maybe your clockbot sends the whole village back in time, while horrified onlookers watch this rapidly rewinding history. Or maybe your clockbot creates an unstoppable soldier, the Time-inator, and sends him back to destroy the world before it begins. ]
[Question] [ I'm trying to design a culture that has access to cooling as a primary source of food preservation. This culture is set in the desert. They will have access to a magical stone that has the ability to create stable volume "bubbles" off themselves. These bubbles would be robust, but temperature permeable. This could be used to say, hold a bubble full of water, rock, or food without risk of breaking or cracking. (Yeah, I get that I could just make them "cooling" stones, but there is a narrative reason for them working in this way specifically). The question is, what is a simple low tech way to give this culture easy access to freezing? Do they need access to electricity? I'm also hoping to be able to apply [isochoric-freezing](https://www.ift.org/news-and-publications/food-technology-magazine/issues/2019/november/columns/isochoric-freezing) into this if possible. I know temperature differences are important for normal freezing technologies, and pressure plays a role as well. Would it be possible to have a passive system using heat from the sun and temperature difference below the surface? If so, what sort of temperature differences are needed? How much of your system would be needed to bring to freezing temperature a certain volume of space? [Answer] Desert cultures made and stored ice centuries before the Romans harvested snow from the mountains for their feasts. The key is that the desert environment loses heat rapidly to the sky after dark; rapidly enough that a skim of ice can form on a shallow puddle by dawn, even when the previous day and the next will approach 50 °C. This ice is gathered before the new day begins to warm and stored (straw for insulation, and an underground chamber with carefully limited airflow, so it collects cold air like an ice cave). End result is that when weather conditions are right, it's possible for a single family to produce tens of kilograms of ice each night, and accumulate hundreds of kilograms per month -- in a climate where you can literally cook eggs on exposed rocks in the afternoon. [Answer] While I don't know of any in desert regions, in some areas there are sinkholes that have an outflow of cold air that can even cause ice to build up. Here is one example, <https://en.wikipedia.org/wiki/Coudersport_Ice_Mine>. This is real natural feature, not a fake tourist trap. [Answer] The rapid release of pressure Have you ever wondered how your air conditioner, refrigerator, or vehicle a/c actually work? Ever wondered why that can of compressed air you used to clean your keyboard became uncomfortably cold? Electricity isn't needed. Ice can be manufactured in a completely mechanical way: Rapid decompression is endothermic The result is cold, and when you do it with enough pressure or enough times, what you get is freezing temperatures. So what your people need to do is use a bellows to fill a bladder in a confined space (call it an "ice house"), they pump up the bladder, then twist a wooden valve to release the pressure all at once. Repeat as necessary. And that's all your (e.g.) car A/C is doing. The motor runs a compressor that forces the refrigerant into a high pressure area, which leads to the cooling vanes where that pressure is decompressed rapidly. As an aside, electricity-dependent cooling can't be done in many ways In fact, I can only think of one off the top of my head, the use of a [thermoelectric generator](https://en.wikipedia.org/wiki/Thermoelectric_generator). [Answer] [gas-absorption refrigeration](https://en.wikipedia.org/wiki/Gas-absorption_refrigerator) technology has been known of for over 150 years. The [Crosley IcyBall](https://en.wikipedia.org/wiki/Icyball) was marketed 90 years ago for home refrigeration before electricity was commonly available. This would not be passive, a source of heat such as a kerosene burner was needed but in the desert solar heating may be enough. [Answer] Heat pipe. Take a 30 foot long chuck of standard 2 7/8" gas pipe. Weld a cap on one end. Other end put a cap with a good valve on it. Put one end in the ground roughly midway. Fill about half full with propane. Allow propane to boil until about 1/3 of the propane boils off. Close valve. Put a ring of these around your cold cellar. In operation in winter when it's cold, propane will boil at the hot (lower) end of the pipe, hit the cold end, condense, and run back down. Net result is that you have a plug of ground that is roughly at the temperatue of the coldest month of the year. In summer when it's warmer at the upper end, the propane just sits there. The working fluid can be any stable material that is a gas at storage temperatures, but liquifies under pressure at that temperature. Propane, ether, butane are simple molecules that work. ]
[Question] [ Prehensile hands have the advantage of not having to constantly touch anything they don't have to - with the exception of things like doorknobs. Feet don't have that luxury, and so in a sense will always be 'dirty'. Even if you're wearing shoes, grabbing something still isn't hygienic. Sentient birds would be facing some issues. Unless the nature of your footwear allows for some way to keep the grasping surface of your foot both away from the ground AND available to manipulate objects. But how? For the purposes of detail, the species I'm imagining is a theropoid race with 3 digits and 1 opposable 'thumb' on each birdlike foot. One thing I've imagined is a kind of 'flip-flop' type shoe with a pivoting joint at the ankle. A regular flip flop can also work, but this one allows the shoe to stay on by moving it at the snappable joint. This design is pretty primitive and exposes the rest of the foot, so wouldn't allow for anything boot-like. Any ideas? [Answer] ## One approach is to look at shoes used by people with [upper-limb amputations](https://www.nicklauschildrens.org/NCH/media/docs/pdf/Presentation-Upper-Extremity-Limb-Loss_810_915-c.pdf) or who were born with missing upper limbs. While your characters are not human and may or may not have partial or full use of hands, the basic premise is the same: how to keep your feet clean so you can use them for hand-like tasks. [Diamond Excell](https://jamaicans.com/videos/the-amazing-inspirational-story-of-diamond-excell-jamaican-american-with-no-arms/) was born with no arms and uses her feet for everything she can. Slip on shoes without socks are what she, and other foot-users seem to prefer. There's a picture of her in some boots at 6:30 in to the video, also 7:02. Her goal is to start her own shoe line. [![enter image description here](https://i.stack.imgur.com/WqUKh.png)](https://i.stack.imgur.com/WqUKh.png) When she cooks, she sits in a rolling chair in the kitchen so she has use of both feet at the same time. [![enter image description here](https://i.stack.imgur.com/XhalP.png)](https://i.stack.imgur.com/XhalP.png) Jessica Cox, who also has no arms, uses slip-on shoes and sits in a chair if she needs to use both feet together. [![enter image description here](https://i.stack.imgur.com/Vn2bw.png)](https://i.stack.imgur.com/Vn2bw.png) A wide variety of shoes are easy to put on and off without use of your hands. Moccasin slipper shoes with light soles (for indoors and occasional outdoor use) keep feet clean and dry and are easy to kick on and off. You can throw these in the wash too, though not too often. [![enter image description here](https://i.stack.imgur.com/88uOk.png)](https://i.stack.imgur.com/88uOk.png) A low boot would work for outdoors. [![enter image description here](https://i.stack.imgur.com/5jQgn.png)](https://i.stack.imgur.com/5jQgn.png) Or just plain old slip-on shoes. [![enter image description here](https://i.stack.imgur.com/2PfM9.png)](https://i.stack.imgur.com/2PfM9.png)[![enter image description here](https://i.stack.imgur.com/qT8VN.jpg)](https://i.stack.imgur.com/qT8VN.jpg) Now, your characters do not have human feet, so obviously human shoes aren't going to be an off-the-rack possibility. I will encourage you though to consider enclosed shoes like the examples I give. Note how people who rely on their feet to do things hands usually do aren't in flip flops or sandals most of the time. Why? Because feet get really dirty in open shoes. Sure, the sole of your foot is protected from stuff you might step in, but I think you underestimate the effects of dust, dirt, mud, and random uck. Far more than you'd pick up with your hands. Indoors your characters would keep floors very clean and use rugs or carpets to keep dust and grit off of feet. Then they'd go barefoot. They would slip on shoes whenever they went outside. The other consideration is cultural. We think dirt is unhygienic and gross. But no animal wears shoes and many use their paws/claws/etc to pick up or manipulate food, or they lick their feet directly. [![enter image description here](https://i.stack.imgur.com/WX3N9.jpg)](https://i.stack.imgur.com/WX3N9.jpg) [Answer] Any glove-like shoe will also work. There is a significant number of shoes in human history that didn't have a separate rigid sole, but were wholly made of soft leather - native American mocassins, early medieval Germanic shoes, chuvaki of people of Near Asia and Caucasus. Such footwear works quite good, unless you need to walk on paved surfaces regularly. From my personal experience I can tell that they are very comfortable in the forest. For humans, such shoes are usually made as soft leather 'bags' for feet, but nothing prevents them from being made more glove-like for someone with longer and more mobile fingers. As for more technological solutions, right now there exist a number of 'barefoot' shoes of sturdy synthetic fabrics with very thin vulcanized sole. Some of them, like Vibram Five Fingers even have separate fingers. So, leather foot gloves for low-tech settings and synthetic gloves with rubber gripping surface for more advanced settings. As for the flip-flops, they can be worn over such foot-gloves when you need to protect them from abrasion - in something like medieval urban settings. In our world, medieval townsmen had worn wooden sandal-like pattens over soft leather shoes to protect them from wet, dirt and abrasion on cobblestone. UPD: that may be a part of much bigger issue of how a race that uses the same extremities to walk and manipulate objects will structure their houses, cities and living in general. It will not be much of an issue while they are living as hunter-gatherers. As soon as they get agriculture and animal husbandry, they get problems - you do not want to eat with something you just mucked animal fecal matter with - the rate of stomach infections will be just too high. The same goes for medieval-style cities with horse-drawn carriages in the streets. I can see feet cleaniness being a big issue, foot-bath being more important market of 'house entrance' then a door. Helping the guests to wash their feet would be even bigger marker if respect then it was in human archaic cultures. Possibly, the structure of the cities would be different, with streets for walking being even more separate from the streets for carriages and pack animals. It would rather look like a system of sturdy poles and narrow bridges raised over the ground level. Street food and it's consumption will also look different - from forks or other similar eating utensils being always carried on one's person, up to vendors putting the food directly into the customers' beaks. The results for the footwear are as follows - glove-like closed shoes are better for situations where you can encounter a lot of dirt and muck. The are also better for raised walkways and poles, since the don't interfere with feet grabbing the surface you walk upon. Sandal-like footwear is more comfortable for situations where you are not that likely to encounter much dirt - for example, indoors, in big buildings where there is not much dirt, but it's impractical to wash the floor all the time. [Answer] Elevated clogs (geta) with toes hanging off the front. <https://en.wikipedia.org/wiki/Geta_(footwear)>[![enter image description here](https://i.stack.imgur.com/cV9AX.jpg)](https://i.stack.imgur.com/cV9AX.jpg) In a therapod or bird like foot, the toe to sole ratio is much longer than in a human. We have short toes and lots of sole. Birds have long toes and small soles. Therapods would definitely use their toes to run, as an ostrich does. But this is polite society. Just as running in geta would be trickier than barefoot, these dinoshoes make it more difficult to run. They support the weight using the sole and keep the toes clean and off the ground. If something must be grasped, the long toes protruding out past the geta are clean and ready for the job. The shoes stay on. [Answer] Does the grasping surface of the foot need to be the same as the walking surface? What if they were on opposite sides of the foot? A foot physiology where the toes bend "upwards" has certain evolutionary advantages, since it would allow your characters to walk while holding items at the same time. To put it in more familiar terms, it would be somewhat like a human hand-walking on the back of their hands. For us, doing so would probably be rather hard without significant damage, since our wrists are not quite meant to bend like that, but it does not have to be the same for your folks. As for footwear, I imagine that open-type shoes, like [flip-flops](https://en.wikipedia.org/wiki/Flip-flops), would perform quite nicely when no protection from the elements is required. When added protection is needed, a glove-like sock made out of cloth or leather would probably be sufficient. [Answer] I'm not 100% certain that you're asking the right question. If you watch a raven solving a puzzle, they tend to use their mouths for "hand-like" tasks, rather than their feet. Regardless, I should probably answer your original question... :-) I suggest a dynamic mechanism that opens and closes the shoe based on body position/foot height. The context in which "hand cleanliness" is important are by definition almost always contexts that are not on the floor. Other than picking up something that has accidentally fallen, one would tend to want shod foothands on the ground, and unshod foothands when the foot is being held at a higher elevation. So I would suggest a mechanism that is anchored to the hip or body (depending on articulation), and that "opens the shoe" when the foot is elevated above the ground. Lifting up the foot, in order to use it as a hand, would expose the clean foot instead of the dirty shoe. Alternatively, one could have the same type of mechanism enclose the foot (and, of necessity, the shoe) in a "clean glove" when the foot was elevated, and remove the glove when the foot was put back into walking position. This is inferior (for reasons of dexterity) to the "open the shoe" approach if the avians wear shoes. But bird feet are not like our feet, and I think it's likely that avians would end up going barefoot most of the time. If so, then an automatically-applied glove would provide almost as much dexterity (no double-layer problem with shoe + glove), and let the birds continue to use their preferred barefoot walking style. As to the specific engineering of the openable shoes or closable gloves, I think that involves more specifics about foot articulation than I have access to. [Answer] Just a fun idea, but have you thought about wheelies? I'm not sure about what sort of era that you are going for, but you could have a wheel+stopper combination. Something that looks like a fingerless glove, but for the feet and it goes up and get's slightly bulky on one side of the ankle. Have the wheel be able to pop out from the ankle and slide under the foot in a hooking motion, maybe something locks into place on the foot-glove, so that way your weight can directly supported by the wheel. Have a stopper be placed near the back so that way you can just rock your self backwards slightly and stand in place on it or slow your movements down. It could also be semi-attached to the wheel mechanism and comes down when the wheel does. Maybe a special button you can press on the ankle to unlock the wheel to move it out of the way & back to it's ankle cartridge/spot, if what you are doing requires use of the full palm of the foot. It'd give you movability and keep your feet of the ground. This would only be viable in a modern environment, with paved roads/sidewalks and non-carpeted buildings. The palm of the foot glove could be well padded or designed to evenly distribute the weight/pressure across the whole palm of the foot. Walking up stairs or inclines would be okay, just center your body of the stopper instead of the wheel. [![enter image description here](https://i.stack.imgur.com/e1KGO.png)](https://i.stack.imgur.com/e1KGO.png) [![enter image description here](https://i.stack.imgur.com/1qgnR.png)](https://i.stack.imgur.com/1qgnR.png) [Answer] Maybe the answer is in your very question. Their feet are always dirty. And, since they are bird-like, they might consider sheathing their talons to be a bad thing. So when they need to do something where they need their feet clean, maybe they wipe off their feet using a cloth they keep for just such occasions and grab tools appropriate to the task. Like for eating they pick up a spoon or knife-like utensil. Similarly, they have gloves that they wear when they need to handle something they want to be kept clean from whatever they walked in or perched on. I imagine their talons would mean their gripping mechanism is different from their sensing mechanism. They could tell something about an object by scraping it and tapping with their talons (or beaks) but soft delicate objects might not work out so well. So where we feel with our fingertips and then our other parts of the hand, they start with talons and then use some spot on their foot that if it got burned or cut, they would still function until it healed. ]
[Question] [ So I'm writing a book that takes place in an endless ocean with islands inhabited by many races, and I'm trying to come up with unique boat ideas for races; well I have most of them, but I would like some help with one race. I call them the Cellene, they have a body shape like most humans but their legs and arms are 25% longer, and most reach a height of 8 feet, the tallest being 10 feet. I don't think boats as we build would work for them so any ideas would be helpful. EDIT: To clear up some things these people only have up to probably the tech that they had around the time of the Roman Empire, and they also live on islands, they wouldn't want to waste wood resources on making larger boats they would make different ships to fit their needs. They are tall, but not all that strongly about the same as an average human. Also, they would be travelling about 350-500 miles per trip between the main islands they live on and much longer for trips out to the islands beyond the center 3 Edit 2: Raditz did clear up some things for me, the real question is I want to have a boat using the same amount of wood, relative storage space and convenience of travel (since this is the only method of travel between islands other then swimming) but just for larger kind of oddly shaped humans. [Answer] So you gave two pieces of information that are very helpful: Roman Era tech and distances of 350-500 miles. Given that they are in an archipelago-style region, I would recommend ships similar to the Polynesian islanders who settled across the Pacific. These ships are open, leaving you without any problems from height. Really, the more pressing concern is ship-building resources. A catamaran uses less wood than a bireme or trireme, so if they are on smaller islands where wood is not in abundance, a catamaran is an excellent choice. Given that your Cellene are weaker than the average human, it would stand to reason that they would use sail over oars as well. With Roman Era tech I imagine you could up the scale of these ships a great deal, facilitating trade and travel. [Answer] I don't see any reason why their boats and ships would look much different than those used by humans with the same tech level from our world. The ability to reach higher masts wouldn't matter, because sailboat usually have masts which are far too high to reach for the crew. That's what [climbable shrouds](https://en.wikipedia.org/wiki/Shroud_(sailing)) are for. If they have lower decks, then those might be a bit higher to accompany their greater need for head space. That means their ship would also need to be a bit wider to achieve the same amount of stability. When the ship has a cockpit, then the different instruments could be a bit further away due to their larger reach. When their center of mass is higher, then the railings would also need to be a bit higher to provide the same amount of safety. So the largest difference you could see is that their boats would be a bit larger on average, just like they are larger. I honestly can not see any other major design difference which could be justified solely by their body shape. In general, ship design is mostly influenced by the mechanical requirements for safely and efficiently moving the ship through the water and by the materials and propulsion technology you have available. Ergonomic concerns come second. When lack of building material is a concern, then they wouldn't build different ships. They would just build less ships. [Answer] ## Boats are not made for transporting people in a pleasant manner Well, most of the boats at least. They have the following requirements in order of importance, and solutions: * Transports as many goods and/or weapons and/or soldiers and/or travellers as possible. Also the food and water for people onboard. + Solution: Make big boats, and use as much of the space as possible for cargo. * Be seaworthy, efficient and fast + Solution: Boats are more or less oval shaped. They have as much sail as possible, they are built with strong materials. * People are needed to control the boat + Solution: take as little space as possible from the space for the cargo, and adapt it for humans (beds, kitchen, toilets, steering room). Boats are cramped because you want to transport as much cargo/guns/soldiers/travellers as possible, not because people wanted them that way. In your case, the ratio living space/cargo space will be a bit higher, but the overall design would not change. The first requirement is, and always has been, the same on earth and for your aliens. So boats have always been as big as possible. Limitation to the size are technology and environment (think Suez canal, available harbours, ...). So: Boats will not be bigger. They will just be able to transport a little less cargo for the same size, because a little more space is needed for the crew. Note: for pleasure crafts, they might build them a bit bigger, so that they don't bump their heads all the time. But, even on human boats manned with humans, people are bumping their heads quite frequently. ]
[Question] [ If I use, say, Greece as a reference for a fictional country, do I need to write that country as mountainous and coastal also? [Answer] Most people would suggest that your culture should relate to the physical geography of your setting. For instance, fashion and food are both going to be dictated to a certain degree by climate. And the history of your setting should be the story of how the culture developed. ...Unless you're going for something otherworldly, like an extra-planar setting that just happens to be togas, crystal spires, and philosophy. [Answer] Nope The simplest answer is "no." You only need real-world geography or geology if that's an important aspect of your story, otherwise the geography/geology is background. I've read and enjoyed numerous stories that have, not just implausible, but geologically impossible — and the stories were great. [Answer] The answer to "Do I need to..." is always no. The answer to "Can I ..." is always yes. You are making your world, what you say goes. The fact that things ended up one way in Greece doesn't mean they couldn't end up differently in your world. In this particular case I would advice against staying too close to your reference. If the reader can understand "Hey, this is Greece!" they will pull all sorts of real-world attitudes about Greece into the story where they don't belong. It is better to use several references and mix and match pieces from them. Some minor sanity checking is recommended but in general readers aren't very critical. [Answer] You can have Greek culture in just about any world setting, and not have to make it up. A nice thing about basing your story on Greek culture is that Greek culture has been in just about every biome at one time or another. Depicted: Macedonia. <https://www.dmwc.org.mk/2017/10/10/the-mountains-of-macedonia-a-winter-wonderland/> [![Macedonia in winter](https://i.stack.imgur.com/jO1RF.jpg)](https://i.stack.imgur.com/jO1RF.jpg) Greeks got just about everywhere back in their heyday. If you want people who are culturally Greek and living in alpine mountains, or in a desert, or in a tropical setting, you can find historical precedent. Also, basing your culture and characters on Cypriots or Alexandrians or Indo-Greeks will put a little space between your work and Percy Jackson's Greece - not that there is anything wrong with Percy Jackson. [Answer] It all boils down to why are you describing your geography. If you are describing that your fictional country protrudes into the sea like Greece does, then describing its mountain/planes might not be needed. If your story is taking place in the inland and the geography has a role there, you have to describe it as much as is needed for the sake of understanding the story. [Answer] I guess this depends on what you have in mind. If you mention Greece (as in using the exact word) then yes, you should stay close to what people think Greece is (mind you, not what it really is, but what people expect). The reason is the obvious: if you had a story in Greece and people do things in endless grasslands or continent-spanning mountain ranges or suffer from the heavy snow in the long, long winters, then people will be very confused. But if all you need for your story are the architecture and the philosophy, then you can have a country looking a lot like whatever you want it. You may want to keep in mind that things like philosophy require a working culture, particularly a well-enough established agriculture to provide in abundance, lest nobody have time for philosophy. And togas really don't work very well in a cold and rainy climate. So, if you use the name, use the image your readers expect. If you don't use the name, do whatever you please. [Answer] It depends on the degree of similarity you require and how believable you want your world to be. I am approaching assuming you wish to retain most aspects of Greek culture. Greeks were/are Greeks, as Romans were Romans, because of the lands that shaped them. Art, architecture, diet, language, political spheres, policies, wealth, all are influenced heavily by geography. People in a landlocked, snow capped northern plain would not developed as the Greeks did. Climate and geography for example have been shown to have influence on language. Humid climates promote [tonal language](https://www.mpg.de/8879447/tonal-languages-institutes), temperature influences volume, thinner air [promotes ejectives](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0065275) etc. The mountainous geography of Greece played into the development of the various Greek [city states](https://greekarchaeology.osu.edu/arch-edu/archaeology) by isolating these ancient cities. The vast coasts of Greece would have effected their diet, their access to trade and thus wealth, the degree of foreign influences etc. In short there is a cause for everything, and if you take the Greeks from their lands, but wish to retain all aspects of their culture you best find reason for it, otherwise it may impact the believability of your world. [Answer] To a point yes fictional geography needs to be rooted in earthly geography; because your audience are human, you, as an author, can't describe geography that we don't have at least some context for. That being said you can change the rules a lot, just have a look at some of the questions on infinite environments when you have a chance. You can do even more and stranger things if magic is part of the setting you're using. When worldbuilding physical geography can be massively important, and usually has at least some bearing on the process, but that doesn't mean that any except the broadest and most basic details need make it into the finished story. The key is to work out what, in particular, about Greece you want to form part of your story; you may want to talk about the island culture of Ancient Greece where over every horizon was a different people with strange customs, or Classical Greek culture the birth place of democracy and scientific method, or maybe you want to speak to the way that the inhospitable interior of later centuries created a coastal culture of fishermen and small farms on the flat edges. If your story is about the ancient Islanders or the late era fishermen then you definitely do need to speak to the geography of the setting, but if you're concerned with the enlightenment of the classical urbanites then it's culture and not geography you're primarily writing about. ]

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