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[Question] [ There are many different calendar systems on earth. Of course, since a fictional world very well may differ greatly from Earth, it makes sense for them to have their own calendar. What are various things that should be kept in mind or thought about when designing a calendar system for your world? [Answer] ### Cosmology and astronomy Calendars will have a strong dependence on the cosmological perspective of the people creating it and their astronomical capabilities, since celestial mechanics determine the day-night cycle, seasons and year length. Obviously they will *count* the seasons and days without having to look at the sky for a number, but most any culture will have rudimentary sky observation information, the least of which will be constellation movement tracking. While astronomy on one hand is obvious as a factor, I mention their cosmological perspective because it can strongly affect how they number things and how complicated and arbitrary their system is. Look at ancient Greek epicycles and Phlogiston for a couple of ideas of how reality gets messed up because you just *have* to have your planet in the middle of the universe and the universe perfect. If a culture has an idea of the world that, for example, disallows the year to be anything close to 400 days, even though the *actual* year is 423 days, they might come up with a year of 846 days and explain that "everything is paired" and "that's why we have 8 seasons and the mid-year festival". ### Mythology The effect of their cosmology is modified and further compounded by mythological beliefs - not only the naming but also the scales involved will be based on what their perspective of the universe is. A culture that believes they were created by deities a few millennia ago, will likely use that arbitrary point in time as the start of their calendar. If they have chosen an arbitrary date for the same event, they might choose to start the year from that date or place it in the middle of the year. These can be completely arbitrary. ### Mathematics and counting Their mathematical capabilities will also affect the form of the calendar. A culture more adept at geometry may prefer to create a calendar that allows geometric relationships when laid down, to determine the relationships of their astrological ideas and the seasons. A culture that has developed complex algebraic concepts might prefer a calendar will composite numerals that compress more information into the structure. Most any calendar will have a simple counterpart though, to make farming use easier. ### Examples Some examples of calendar variation are these: * In the [Gregorian calendar](http://en.wikipedia.org/wiki/Gregorian_calendar) year enumeration begins at the religion-based year that the Christian Messiah was born, yet it is used today by other cultures and people who don't share the religion itself. The [Hebrew calendar](http://en.wikipedia.org/wiki/Hebrew_calendar), despite strong cultural relationships with Christianity, beings its enumeration *much* earlier, on the order of millennia. The [Mayan calendar](http://en.wikipedia.org/wiki/Maya_calendar) uses a mythological starting point, much like the others, that is also millennia before the Gregorian year zero. * The Gregorian calendar still uses the Roman names for months, many of which are references to the Greek pantheon correlated to the planets and others being the names of Roman emperors (or coinciding with them). While this is a minor point, the naming can depend on a long history of cultural takeovers and shifts, as well as the degree of reverence that the people place of different parts of their world. The [Chinese](http://en.wikipedia.org/wiki/Chinese_calendar) use animals for the [12-year astrological cycle](http://en.wikipedia.org/wiki/Chinese_calendar#Cycle_of_years) for instance. * Some calendars have numerous epochs. The Gregorian calendar can be considered to have two: BC and AD, but the Hebrew calendar has multiple ones. The fictional calendar in the Elder Scrolls universe also had multiple epochs, that begin and end based on the predictions of the scrolls and historical events. This seems to be mythology dependent, much like determining a starting point. * The number system can differ - we use decimal, or base-10, but the Mayans used base-20. Among ancient cultures, there were many kinds of numeric bases for their counting and there was little consistency. The Sumerians used base-60 and I've read of base-12, base-24 and others being used, sometimes by the same cultures. A good example of mixing is the Imperial System for measurements: A foot is 12 inches, a yard is 3 feet, a mile is 1760 yards. While cultures using the system didn't mix bases, if there was a complex calendar system, it may well use different bases for different layers, to compress representations. ### Oddities Some peculiarities: * The Mayans had 2 kinds of years: lunar and solar years - the lunar year lasted 260 days while the solar roughly 365 days. These formed a cycle that completed every 52 solar years. So, perhaps by their perspective, there were long and short years. They also used a different count for long periods of time and short periods of time. Many cultures have so called "lunisolar" years. * Many calendars, such as the Chinese and the Gregorian, have fudge factors to make sure alignment is maintained over inaccuracies that collect over long periods of time. For us it's February 29 (nearly) every 4 years, for the Chinese it was a month or two added every now and then. --- Summarizing, the information you should know before making a calendar is: * Actual astrophysical orbit, including other planets and the moon(s), if any exist * Creation and cosmological mythology of the culture * Their mathematical system and capabilities * Their cultural activities that use the calendar * Their history, which will determine calendar characteristics that stay stable over time because, once established, they have no reason to change (such as year zero) Wikipedia has a lot of information on the aforementioned calendars and is a good place to start for more. [Answer] My system for generating a calendar is fairly simple: 1. When does it start? 2. What are you counting? Let's start with the first one, when your calendar starts is often defined by your civilisation's history. It may be the foundation of the nation, the date that the aliens were defeated, the date the god(dess) created the world. This will be very specific to your world. Second, what are you counting? The traditional is a year, one rotation of the world around the sun but there's no reason you can't count seasons, days or any other unit. The unit selected should reflect the society using it, an ancient civilisation are unlikely to use precisely measured atomic periods, they're more likely to use natural and observable times such as a year. Equally a multi-planet empire is unlikely to use the orbit of one of it's planets as a measure... what about the others!? As for more granular measuring days is a very obvious one (sunrise/sunset is very hard to ignore regardless of your technological level) but why not count hours since sunrise? * The number of shortest days since the last great volcano eruption * The number of seasons since the foundation of the nation * The number of winters since the "beginning of the world" Finally note that a lot of calendars have some kind of scaling letters. AD/BC, The 1st, 2nd, 3rd or 4th ages. To a little bit of spice why not add in some letters to your date? 142nd day of 194 DL (Dawn of Light or some equally vague/poetic units). [Answer] The main reason to have a calendar is to predict important points in time (when to sow, for example). Those points are often tied to the year. Identifying points in the year is most reliably done with astronomical markers (for example, IIRC the Egyptians used the appearance of Sirius above the horizon as sign to start sowing). Also very obvious observable periodic changes (the moon phases!) will likely enter into the calendar (if living on the sea, the moon phases will also intimately be linked to the tides; note however that adoption of lunar cycles may also have been driven by the fact that the female fertility cycle is very close to it). The base unit of a calendar normally is the day (when there is no night-day cycle, I can imagine another base unit being used). Anything below that base unit is time keeping, and not related to the calendar (except for the defintion when a day begins; the usual calendar uses midnight — the middle between sunset and sunrise — while the Jewish calendar uses the sunset as start of the day. After the base units are set, numeric properties play an important role. For example, the moon cycle is between 28 and 29 days. 28 = 4\*7, while 29 is prime. Usually divisible units are preferred; the 7-day week most probably is related to the 28-day moon cycle. On the other hand, there are about 13 28-day months in the year, which again is a prime; however, make it 12 months of 30 days, and you have two quite divisible numbers; and even better, both are obtained by dividing the same number, 60, by a small number (2 or 5). Of course, that way you inevitably get a mismatch of your cycles (for example, a year is between 365 and 366 days long, with 13 28-day months you get 1 to 2 days too little, with 12 30-day months, you even get 5 to 6 days too little. That can be solved by having a few "special days" to fill up the year (if the priests set the number of special days according to astronomical observations, this also saves you the trouble to make complicated rules like leap years), or it can be solved by making some sub-units a bit longer or shorter (like our calendar, where we have some months with 30 and some with 31 days, with a mostly regular pattern — the irregularities (and the much shorter February) are due to later modifications of the calendar by Roman emperors (for example the emperor Augustus — after renaming the month Sextilis to August — wanted to have his month (which up to then had 30 days) to also have 31 days, so he gave it another day, exchanged the month lengths of the following months (maybe because otherwise there had been three 31-day months in a row), and took the extra day away from the February (which already had a differing length anyway). The latter also shows a third influence on the calendar: Messing with the calendar for various reasons, from actual time-keeping reasons (adapting the leap year rule to better fit the astronomical year, after the difference becomes problematic, as done with the Gregorian calendar) over cultural/religious reasons (resetting the date number from Roman to Christian calendar, based on the claimed birthday of Christ — the fact that Christian year numbers are divisible by four exactly if Roman year numbers are, which allows for the same leap year rule to result in the same leap years, makes me suspect that the birthday of Christ wasn't the *only* consideration when fixing the starting point) up to just self-esteem of emperors (the Augustus example above). So in short, the following things affect the calendar: * The cycles important to daily life, as well as easily observable cycles in nature (especially astronomical ones). * Numeric properties, especially divisibility (but also the religious or superstitious significance of numbers may enter here; OTOH that often is also derived from the divisibility). * Intentional changes to an existing calendar, often with a goal not directly related to timekeeping considerations. [Answer] Let's start with the most popular calendar in the English speaking world, which has 12 months broken into days; the number of which range from 28 through 31. Those days are then organized into periods of 7 day weeks. One would conclude that by dividing seven into the largest number of days in a month one would determine that the maximum number of horizontal lines of weeks would be four and a bit, or five weeks (rounding up). 31 / 7 = 4.43, rounded up to 5 The truth is that since the calendar makeup is comprised of some prime numbers, the months will often start on different days of the weeks and end on them on different days of the week most often too. Therefore, six lines of dates are needed to lay out a month without resorting to squishing more then one day in a single square. Now, we live in a simple solar system and have a single moon revolving around a single planet with a single star at the center. Imagine how different a calendar might be if it took in the influence of a double moon (such as Mars has). Or if our Earth and some other planet revolved around each other on our annual orbit... or if we had a binary star at the center of our solar system. One other thing that may affect a calendar's layout would be if our planet revolved around the sun with its axis at 90° to the its travel direction around the sun. Our calendar is affected by our culture as well and needs to address the strict observance of religious holy days, and political observances. It's interesting to notice that in spite of the majority of this planet is covered in water, it is left to imposing a tide chart onto the calendar rather then allowing the time chart to drive the organization of the calendar. Additionally, any agricultural influence is made to superimpose itself on top of the religious/politico calendar too. Many of Earth's cultures did fine and existed for centuries without a calendar at all; the American Indians for example. It bears reminding ourselves that some cultures in South America exist today with only a very vague sense of time and no counting system beyond the numbers two or three. So if I said to you, "I will be gone a long time." It is up to you to decide when the "long time" has passed; be it days, weeks of days, or even months or years. A very tricky thing when one barely imagine past tomorrow or the next day at best. [Answer] In general calendars are shaped by events that can be seen or observed and for the most part these are astronomical events. In the tropics a year has little meaning but in temperate and polar regions it is a really big deal, so it can be expected that that will take an important role. Days are the other obvious division - light and dark marking periods of activity. Between the year and the day though there is a huge range of time, so it makes sense to split that up. Obvious approaches are seasons, or if you have a moon then phases of the moon and tide again is very visible and dramatic and obvious. A planet with multiple moons or multiple suns would be much more complex but really all you need to do is stop and look at your planet and its environment. What regular events would its inhabitants see and how would they use those events to measure the passage of time. [Answer] One important things wasn't mentioned: the calendar can be heavily influenced by politics too. Each "era" starts with the year new sovereign or dynasty started their rule. Ancient Egypt, or even Old Testament Izrael used this system. A randomly picked Old Testament example: "In the eighteenth year of the reign of Jeroboam son of Nebat, Abijah became king of Judah..." (1Kings 15:1) This system has obvious drawbacks. It requires maintaining long lists of kings and lengths of their reign to make counting years over a long span possible. This is not exact, especially if some rulers are "politically incorrect" enough to be erased from history (Achnaton and the following two pharaohs make a good example). And this requires the culture to be dominated by one or at most two (Izrael + Judah) sovereign lineages, otherwise it is a mess even for contemporaries. On the other hand, with low literacy level where only priests and kings' scribes need to count years exactly, this system was quite practical for the administrative (bureacrats knew who were the last few kings and how long did they reign), and it pleased the kings, in some cultures seen as human gods. The priest may or may not have an alternative calendar better suited for long-range year counting. ]

[Question] [ I am attempting to create fictional, stable P-Type binary system, featuring a gas giant in a stable orbit, with a habitable Earth-like moon. “[Is a Jupiter-sized planet plausible in a habitable zone?](https://worldbuilding.stackexchange.com/questions/4729/is-a-jupiter-sized-planet-plausible-in-a-habitable-zone?lq=1)” has some interesting and useful information about gas giants in the circumstellar habitable zone of a system, and “[Can a gas giant have its own habitable zone?](https://worldbuilding.stackexchange.com/questions/6909/can-a-gas-giant-have-its-own-habitable-zone)” has some good information about the potential of a gas giant having its own habitable zone, separate from the circumstellar habitable zone. Within the constraints of this fictional system, I have a habitable zone spanning between 1.976 AU and 2.808 AU, and the following considerations. * Gas giant would need a stable magnetosphere. Jupiter and Saturn may be useful examples. * The moon's mass must be great enough to sustain an atmosphere. In this instance, a nitrogen/oxygen atmosphere. It is estimated that a moon with a Mars-like density, would need at least 7% of Earth's mass in order to support such an atmosphere for several billion years. * Both gas giant and the habitable moon must maintain a stable orbit. Simulations would suggest that to maintain a stable orbit to a gas giant, or a brown dwarf that orbits 1 AU from a sun-like star, would require a moon orbital period of less than 45–60 days. * The moon itself must be capable of generating its own magnetosphere in order to deflect stellar wind and the gas giants' naturally generated radiation belts. * There is a high likelihood that the moon would be tidally locked with its parent world. Monoj Joshi, Robert Haberle, and their colleagues suggest that the effect of tidal heating could support conditions amenable to habitability. Additionally, tidal effects may allow for plate tectonics, causing volcanic activity and a regulation of the moon's surface temperature. The potential, resulting geodynamo effect would allow for a strong magnetic field. * Balance: The moon should be large enough to support tectonic activity, dense enough to support a strong protective magnetosphere, close enough to the gas giant to maintain a stable orbit, and be far enough away that its own magnetosphere may better protect from sputtering caused by its parent worlds' radiation belts. * It is suggested that the larger and denser a terrestrial, water-rich world, the further out its habitable zone extends. * The moon does not necessarily need to be an earth analog, and may simply be demonstrated as habitable to human life. * The gas giant does not necessarily need to be within the habitable zone and may cradle the outer limits of the circumstellar habitable zone, or be further out provided it can be demonstrated that the orbiting moon could feasibly support human life unassisted by technology. i.e. Robin Crusoe could become stranded on the moon, and survive. Ready for the fun part? If the terrestrial moon must be of a certain size to display tectonic activity throughout its life, as demonstrated in the difference between Earth and Venus (Venus being about 85% the size of Earth), then an Earth-sized moon (or larger) would be preferable. To the best of my understanding [this paper](http://arxiv.org/pdf/1410.5802v1.pdf) suggests that a world of this size, wouldn't be formed in the accretion disk of a gas giant (but I may have misunderstood), however, after the migration of a gas giant, the mixing to inner system and outer system debris has shown in simulations, to allow for the formation of water-rich terrestrial worlds. The paper does at least suggest that larger bodies may be captured, and pulled into orbit by a gas giant. So, let's say our gas giant migrated from the frostline of the system, to somewhere near the circumstellar habitable zone, and afterword, as the orbit began to stabilize, a new terrestrial world began to take shape. Its orbit took it near enough to the gas giant to be pulled into orbit of the planet, and over time, their mutual orbits stabilized. * How can I figure out how large the gas giant must be in order to capture this moon, and establish a stable orbit? * Tidal locking of the moon may be an issue, but also may be compensated by its orbit around the gas giant. How can I determine how far the moon would need to orbit the gas giant, to not be tidally locked? [This topic](http://cosmoquest.org/forum/showthread.php?106773-NOT-tidally-locked-moons) has some interesting points. Here is my hypothetical. The gas giant cradles the outer limits of the circumstellar habitable zone in such a way that the captured moon passes through the circumstellar habitable zone during each rotation. The size of the moon is large enough for tectonic activity, which may in turn, be aided by gravitational forces from its primary. The moon is also dense enough, with an iron/nickel core, to produce a strong magnetosphere, which if further aided by tectonic activity. Tidal forces are affected by the gravitational pull of the primary, throughout the moons orbit. Keeping the world warm enough to sustain liquid water, I don't think will be an issue, and would instead be a matter of striking a balance between orbital distance between the primary and the system's stars. I feel like I am missing a few things. What are your thoughts on how I can work out a viable, habitable moon in this scenario? Originally I asked this [on Astronomy](https://astronomy.stackexchange.com/questions/8458/questions-about-a-fictional-binary-system-and-habitability?noredirect=1#comment10108_8458), and it was suggested that I ask here in Worldbuilding instead. [Answer] Let's work out some factors. * **Luminosity** You gave the radius of the inner edge of the habitable zone as 1.976 AU and the outer edge as 2.808 AU. From this, we can calculate the luminosity of the star. There's an explanation of how to do this on [Planetary Biology](http://www.planetarybiology.com/calculating_habitable_zone.html). The formulae are $$r\_i=\sqrt{\frac{L\_{\text{star}}}{1.1}}$$ $$r\_o=\sqrt{\frac{L\_{\text{star}}}{0.53}}$$ Plugging in your numbers, I get a luminosity of $$4.295 L\_{\odot}\text{ (inner radius)}$$ $$4.179 L\_{\odot}\text{ (outer radius)}$$ I'll average those, giving us a luminosity of $4.237$ times the luminosity of the Sun. But a [P-type orbit](http://en.wikipedia.org/wiki/Circumbinary_planet) is around two stars, as you said, so we divide by two to get an average luminosity of $2.112$ solar luminosities. We can assume that the two stars are similar because they most likely formed together, and have similar properties. * **Mass** The [mass-luminosity relation](http://en.wikipedia.org/wiki/Mass%E2%80%93luminosity_relation) can tell us the masses of the stars. It is $$\left(\frac{L}{L\_{\odot}} \right)=\left(\frac{M}{M\_{\odot}} \right)^a$$ The stars likely have masses similar to the Sun, so we can assume $a \approx 4$. The left side is $4.179$. We write $$4.179^{\frac{1}{4}} \times M\_{\odot}=M\approx 1.430M\_{\odot}$$ So each star is about $1.430$ solar masses, leaving a combined mass of $2.860$ solar masses. * **Orbital period of the gas giant** [Kepler's Third Law](http://en.wikipedia.org/wiki/Kepler's_laws_of_planetary_motion#Third_law) tells us that $$T=\sqrt{\frac{4 \pi ^2}{GM\_{\text{star}}}r^3}$$ Here, $M\_{\text{Star}}$ is actually the mass of both the stars. If the radius is in the middle of the zone (at about $r=2.392$ AU) $$T=\sqrt{\frac{4 \pi}{6.673 \times 10^{-11} \times 5.689 \times 10^{30}}(3.578 \times 10^{11})^3}=6.902 \times 10^7 \text{ seconds}= 800 \text{ days}$$ * **Orbital radius of the moon** Here we just go in reverse. We do need the mass of the gas giant, though - so going from the graph on [TimB's answer here](https://worldbuilding.stackexchange.com/questions/4729/is-jupiter-sized-planet-plausible-in-habitable-zone/4733#4733), I'll pick about 5 Jupiter masses, or $9.49 \times 10^{27}$ kilograms. The period will be in between the values you said, so about 52.5 days, which is $4.536 \times 10^6$ seconds. We put this all in and get $$r=\left( \frac{6.673 \times 10^{-11} \times 9.49 \times 10^{27}}{4 \pi ^2}(4.536 \times 10^6)^2 \right)^{\frac{1}{3}}=6.911 \times 10^{6} \text{ kilometers}$$ Obviously, it's still in the habitable zone. But it's *far* away - although that's because the gas giant is so massive. You may want to opt for a shorter period. This system setup appears to be viable if you move the moon closer to the gas giant, giving it a smaller orbital period. * **Tidal Locking** The formula for [the time it takes for a satellite to be tidally locked](http://en.wikipedia.org/wiki/Tidal_locking#Timescale) is $$t \approx \frac{wa^5IQ}{3Gm\_{\text{planet}}^2k\_2R^5}$$ The factors are described on the Wikipedia page. Here, we can say that $I \approx 0.4m\_sR^2$, so $$t \approx \frac{0.4 wQR^2a^6}{3Gm\_{\text{planet}}^2k\_2r^5}$$ Since $$k\_2 \approx \frac{1.5}{1+\frac{19 \mu}{2 \rho gR}}$$ and $g \approx \frac{Gm\_s}{R^2}$, $$k\_2 \approx \frac{1.5}{1+\frac{19 \mu R}{2 \rho Gm\_s}}$$ $$k\_2 \approx \frac{3 \rho Gm\_s}{2 \rho GM\_s+19 \mu R}$$ $$t \approx \frac{0.4 wQR^2a^6(2 \rho GM\_s+19 \mu R)}{9G^2m\_{\text{planet}}^2 \rho R^5}$$ With $Q \approx 100$, $\mu = 3 \times 10^{10}$, $R \approx R\_{\text{Earth}}$ and $\rho = \rho\_{\text{Mars}}$, you can figure out the tidal locking time. I'm in a rush, so I don't have time to do the calculation, but I may include it later. > > How can I determine how far the moon would need to orbit the gas giant, to not be tidally locked? > > > Tidal locking will occur at some point in time. You can't get around it. Tidal forces will also be problematic because moons orbiting gas giants will likely experience tidal forces so strong that tidal heating can render the moon uninhabitable (see [Heller & Barnes (2013)](https://arxiv.org/abs/1301.0235)). --- **Capture - Corrections** In my original post, I naively said that there are a bunch of scenarios where capture would be possible. This, as HopDavid pointed out, is blatantly false, because the planet would be traveling in a hyperbolic orbit relative to the gas giant, and so would escape its pull rather easily. So it has to have its orbit modified somehow. My suggestion would be an interaction with another body, preferably another gas giant. This could change its orbit such that gravitational capture by the original gas giant is possible. Without this sort of interaction, the planet will just scoot away. --- **Section on the moon's properties** This may be list-like, but it's the best I can do. * **Mass:** You required an atmosphere and a magnetosphere. Both of those require a planet with the right mass and size, as well as composition (which I'll get to). Not many moons have atmospheres complex enough and dense enough to support life. In fact, [Mercury](https://en.wikipedia.org/wiki/Mercury_(planet)) can't support an atmosphere. But mass isn't the only thing that plays into this. [Titan](https://en.wikipedia.org/wiki/Titan_(moon)), one of Saturn's moons, has a mass less than twice that of Mercury, yet it has [a rich atmosphere](https://en.wikipedia.org/wiki/Atmosphere_of_Titan). As [Jim2B pointed out](https://worldbuilding.stackexchange.com/questions/7270/habitable-moon-of-a-gas-giant-working-out-the-sizes-and-distances/7277?noredirect=1#comment115675_7277), though, such a planet wouldn't be able to hold onto water vapor, as this chart shows, because its escape velocity would be too low: [](https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Solar_system_escape_velocity_vs_surface_temperature.svg/819px-Solar_system_escape_velocity_vs_surface_temperature.svg.png) Image courtesy of Wikipedia user Cmglee under [the Creative Commons Attribution-Share Alike 3.0 Unported license](https://creativecommons.org/licenses/by-sa/3.0/deed.en). Also, the maximum mass of the moon is related to the mass of the parent planet, meaning that for a more massive moon, you'll need a much more massive gas giant for it to orbit. You can attribute this to a few factors: * The presence of Saturn's magnetosphere * Low temperatures * A weak solar wind at that distance from the Sun. You've got the distance, the weak stellar wind, and the presence of a gas giant and its magnetosphere. So you really want to aim for a mass similar to that of Titan, at $1.3452 \times 10^{23}$ kilograms. + **Size:** You don't want anything too tiny, because the density of such a body is far greater than expected. Conversely, you don't want anything too big, because the surface gravity would be weaker than you'd like. So go for a surface acceleration of perhaps $0.5g$ - half that of Earth. You can figure out your average radius using $$g=\frac{MG}{r}$$ So you can see why we needed the mass. + **Composition:** You don't want an environment that's hostile to life, so perhaps it would be best to mimic Earth as much as possible. Choose silicate materials for the outer layers, but remember to have nickel and iron for the core. These can help produce that moon's magnetosphere - a crucial component to retaining an atmosphere. Mars' lack of a magnetosphere has contributed to it slowly losing its atmosphere. [Answer] An object's speed about a star is given by the [Vis Viva equation](http://en.wikipedia.org/wiki/Vis-viva_equation): $V=\sqrt{GM(2/r - 1/a)}$ Where a = semi major axis of ellipse GM = Gravitational constant times mass of star r = distance from star's center. Presumably a earth sized body and a gas giant in their own star centered orbits would have different values for a, semi-major axis. When they cross orbits they'd both be the same distance from the star so we could use the same value of r for both moon and gas giant when they cross orbits. So they would have different speeds with regard to the central star. Their orbits would also likely intersect at an angle. Here is a pic:  The velocity difference in their star centered orbits is shown in red. I will call the velocity indicated in red $V\_{infinity}$. [Here](http://hopsblog-hop.blogspot.com/2013/03/what-heck-is-vinf.htm) is an explanation of Vinf When the incoming body enters the gas giant's sphere of influence, the big planet's gravity is the dominant influence so it no longer makes sense to model the path as an ellipse about the star. Now the moon's path is better modeled as a hyperbola about the gas giant. [Speed of a hyperbola](http://en.wikipedia.org/wiki/Hyperbolic_trajectory#Velocity): $V\_{hyperbola}=\sqrt{V\_{escape}^2+V\_{infinity}^2}$ If $|V\_{infinity}|>0$ then the incoming body's speed will exceed the gas giant's escape velocity. If $V\_{infinity}=0$ then the incoming body's speed will equal escape velocity and the orbit will be parabolic. Unless there is another influence beside the star's and gas giant's gravity, an incoming body from another orbit won't be captured by the gas giant. Other influences are possible. If the gas giant already has moons, collisions or swing bys could shed the incoming body's speed wrt gas giant. Or if the moon passes through the gas giant's upper atmosphere and sheds velocity via aerobraking. Large stable moons probably would have formed in the gas giant's neighorhood during accretion of the protoplanetary disk. See [Wikipedia's article on the formation and origin of Jupiter's moons](http://en.wikipedia.org/wiki/Moons_of_Jupiter#Origin_and_evolution). [Answer] This scenario appears to cover most of the factors, though my reading of the [Water Ice Lines and the Formation of Giant Moons Around Super-Jovian Planets](http://arxiv.org/pdf/1410.5802v1.pdf) paper you quoted seems to indicate that formation of moons such as this is *not* all that unlikely, just that it would be necessary for the super-jovian planet to migrate to a closer solar orbit with its moons, which would most likely be retained. Tidal locking is a factor of distance and mass. The larger the mass and the distance, the less effect gravitic tides would have on the rotation of the moon, and hence the longer the period required for it to spin down to a synchronous rotational period. An earth-sized moon may still have a non-synchronous rotational period. You need to determine the period over which life evolved or arrived due to some sort of panspermia in order to determine the likelihood of tidal locking by the time your world becomes the focus of your story. Certainly, you would get plate tectonics in such a system. Also, the super-jovian planet eclipsing the sun(s) would provide a major seasonal factor, probably greater than any circumstance of axial tilt or binary star position. However, since a super-jovian planet is likely to be a brown dwarf, this factor may not be as severe as the IR output of the brown dwarf may provide some minimal heating, preventing rapid or total freezing. It is likely that such a world could be human-habitable, albeit with severe seasonal variations in climate related to the moon's position relative to the super-jovian planet and the primary stars. ]

[Question] [ For all of the combat machine we see in real life, they are painted in colors to blend into the background and lower visibility in every spectrum. Except for when they are participating in a parade, their paintjob will always put "stealth" and "you didn't see anything" as the first piority. But I want to see a world with some--not all--but some of the machines to be painted in garnish and fancy color, regardless of whether they are tanks, fighter jet, or even huge bipedal mech piloted by some whiny kid that need to be fixed by two bright slaps. This world's technology, civil right, human right, and political wisdom is at least equal to modern era. But anything else other than these requirements, can change. So what change in history or human psychology will lead to flashy and anime-esque weapons a regular sight on battlefield? [Answer] ## It is Urban Camouflage The [International Style of Architecture](https://en.wikipedia.org/wiki/International_Style_(architecture)), well known for is hundreds of different shades of greys, off-white, near-black, and beige was popular throughout most of the 20th century, but has fallen out of fashion. This color scheme is represented in what we today call [Urban Camouflage](https://en.wikipedia.org/wiki/Urban_camouflage). But in this drab palette's place, a new urban pattern is emerging. People don't want to see more concreate and stucco, they want color. So, in the 21st century, bright and highly saturated colors with outlandish patterns become the norm in cities across the world until 20th century urban camo makes you stand out like a business suit in a gay pride parade. To adapt to this change in architecture, urban warfare weapons are painted in bright colors to break up their outline using [Disruptive Camouflage](https://en.wikipedia.org/wiki/Disruptive_coloration) in colors you would expect to find in the new urban combat arena, just like we do today with our dull coloration. [](https://i.stack.imgur.com/azsOF.jpg) [Answer] **Fighting enemies who see differently** These days deer hunters tend to wear vests that are highly visible to other hunters (in order to reduce the chance of being shot accidentally) but are effective camouflage against deer (which are effectively red-green colourblind), as discussed in [this](https://outdoors.stackexchange.com/questions/19599/are-elk-and-deer-colorblind-to-blaze-orange-pink-clothes) question. So if you want bright colours on the battlefield, fight an enemy that doesn't perceive colours the way humans do. Possibly the enemy is entirely blind in the human visual spectrum and "see" by sonar, radar, infra-red, ultraviolet or in some other way. In this case it makes much more sense for human combatants to make themselves highly visible to other humans in order to increase battlefield awareness, facilitate search and rescue and avoid friendly fire while making human combat vehicles "stealth" in the non-visual areas the aliens use. [Answer] **Stealth is not feasible.** You have a fuel or power source, Element X, that provides tremendous amounts of power. Tanks can fire super-powerful railguns or particle beams, mechs can jump ten times their height, power armored troops can throw cargo containers like duffel bags. Any unit or vehicle using Element X is going to beat anything that isn't in a straight-up fight, by a huge margin. It's great... ...except that you can't hide it. The emissions or whatever else that Element X gives off when you use it for power are obvious, no matter what you do to try to hide. There's no sense having sophisticated camouflage when you're still going to be horribly obvious. You might as well be visible so that you don't spook friendly forces into accidentally attacking you. [Answer] This existed in real world naval warfare and was called **Dazzle Camouflage** Per Wikipedia: "Unlike other forms of camouflage, the intention of dazzle is not to conceal but to make it difficult to estimate a target's range, speed, and heading. Norman Wilkinson explained in 1919 that he had intended dazzle primarily to mislead the enemy about a ship's course and so cause them to take up a poor firing position." A vivid paint job with confusing patterns can disrupt visual range-finding and tracking. Dazzle camouflage only fell out of use during WWII when radar became common. Why is Dazzle camouflage part of the meta again? Because in your setting, advanced radar jamming and other technologies have forced people to rely on visual tracking, just like before WWII. As a bonus it's probably going to be more effective against an AI's visual tracking than a human's. Edit: I have learned that this principle has been applied to disrupt AI surveillance (eg facial recognition) in recent years under the name **CV Dazzle**. [Answer] Pride & Confidence. I want you to see the tank that blows you up. My family, my town, my nation... we built this to defeat you, and you will see it coming, but you can't do anything about it. [Answer] It is required by treaties. In our world we have a number of agreed upon rules of warfare, some of them fairly arbitrary. Shooting soldiers is accepted, but killing them with chemical weapons is not. Soldiers who don't wear uniforms can be treated as spies or terrorist and don't get the usual protection prisoners of war are entitled to. And so on. It would be a perfectly reasonable rule that military vehicles are forbidden (under their equivalent of the Geneva convention) to use camouflage. That way, sneak attacks are less likely, there is a lot more clarity in terms of who is on which side and who is a civilian, and greater international trust is achieved. Anyone trying to blend in with the background would be considered a terrorist. A rule like this tends to benefit the stronger nations over the weaker nations - if you're the equivalent of North Vietnam trying to fight off the Americans, you have greater need of guerrilla tactics. But the fact that it benefits the strong nations is one of the reasons the strong nations came together to pressure everyone else to agree to this rule. [Answer] **Asymmetrical warfare** Combat machines in this world are stealthy because they have foes that can take them out. In a world where there are foes who can not take out a combat machine, a flashy one can be useful in some circumstances to warn people to not even try an attack, or remind them of the firepower that will be brought to bear in event of war. **Close-range combat** Military uniforms took a distinct turn for the drab when it became feasible for snipers to be commonplace. The advantages of distinctive and easily seen uniform for close combat were trumped for the disadvantage of being a good target. This can be something taking out long-range weaponry -- a chemical in the air that disables gunpowder -- or superior defenses to bullets and rockets that make close range fighting essential and bring back the advantages. [Answer] **Too many solar flares** Once upon a time (15th - 18th century) the soldiers in the army used to wear uniforms with vivid colors, so the commanders could see where everyone was and understand the evolution of the battle with their own eyes. And that was needed **because of the lack of instant communication between the elements of the army**. Actually I´m going to include here a question in another board that covers specifically that topic: <https://www.quora.com/Why-did-15th-18th-century-armies-choose-bright-colors-for-uniforms-in-battle> So, Let´s imagine a world where that same situation exists (lack of instant communication between the elements in the army). What could cause that situation in a scenario with the technology of our "modern era"? Well... I think solar flares could do the trick. In an scenario with solar activity intense enough, and if that solar activity becomes "the new normal", radio communications could be impaired, and (even if you have modern technology) you will have to redesign your civilization and you may need to invent new ways to combat in the field, and eventually, a good idea could be to paint with vivid colors your combat machines, going back to those 15th-18th century strategies. [Answer] **Reality TV** The actual warfare is being livestreamed and monetized to external consumers that treat them how RTS streams are watched today. The additional money gained from this more than offsets any benefit to having camo paint, and soldiers and pilots may have their own unique paint jobs so that they are easier to pick out of the action by their fans and sponsors. Either scanners and satellite images are powerful enough to completely eliminate the fog of war anyway, or maybe the consumer of the livestreams is powerful enough to enforce the forbiddance of one side viewing the streams from the other and are willing and able to use the banhammer on whichever side is found to be 'cheating'. [Answer] ## Stealth is impossible or very hard. Power use, scanning tech, and all have improved to such a degree that stealth is impossible. Enemies can always see you, and so there's no point painting your combat suit one colour or another. Perhaps very rare experimental vehicles can hide, but the vast majority cannot. ## Morale is important. [Nose art](https://en.wikipedia.org/wiki/Nose_art) used to be very common, where pilots of fighter jets add art to their planes. Several studies and wars in your world proved that pilots and drivers with more art on their vehicles won fights. Their emotional connection with their vehicles meant they trained harder and spent more effort repairing them. As such, every vehicle from an competent military has a paint budget to help encourage the pilot to take care of their vehicles. [Answer] **They have active optical camouflage devices that can be turned on/off** Your machines have optical camouflage devices, like the capes in Ghost in the Shell. Once turned on, they are almost invisible to the eye. So they can show as much bright colors as they want, when they engage they can just turn the device on.. You can even think of things like the chameleon cells at their surface, so they can even change colors on the fly. [Answer] **Looking back at the history of war, we can note that the opposing sides are colourful when the need to tell friend from foe was more important than camoflage.** **1a. Before the invention of effective long range weapons** A long range weapon lets you take out your enemy as soon as you can see him. If you are virtually guaranteed to see him before he comes in range of your weapon, then there is no point in him using camoflage. Where ranged weapons fail and you enter into the confusion of hand-to-hand combat, the important thing is to be able to tell friend from foe. In the Napoleonic wars and the American war of independence, we see the Americans and the French in blue uniforms and the British in bright red. Although guns were available, they were slow and cumbersome to operate (hence the phrase "don't shoot till you see the whites of their eyes.") The bright red British uniforms persisted until the [anglo-zulu war](https://en.wikipedia.org/wiki/Anglo-Zulu_War) in 1879 (see also the film Zulu starring Michael Caine.) But by 1899 in the Boer wars the British were using khaki uniforms. The significant difference was that their Dutch opponents had guns whereas the Zulus didn't (except ones they had captured from Europeans.) **1b. when your world physically prevents the use of ranged weapons** Ranged weapons are of limited use in a thick atmosphere or underwater. Removing aircraft and fast ships from the equation makes camoflage of submarines of limited use. If you have so many submarines that it's important to tell who is who, distinctive "team colours" become desirable. **2. When you are winning and don't want to be hit by friendly fire.** During the last year of WWII, the Nazis were losing and Allied forces (re)-invading Europe dominated the air. The Allied planes were painted with black and white [Invasion Stripes](https://en.wikipedia.org/wiki/Invasion_stripes) to make it clear which side they were on **3.(futuristically) when there are other means of detecting you** If your enemy can "see" you by other means (infra red night vision, sonar, potentially the electrical interference given off by your vehicle) it doesn't matter what colour your vehicle is. [Answer] A virtual requirement of practical 10 meter tall Mecha is that they have some technology that makes them virtually invulnerable to modern tanks, artillery and ground attack aircraft. That in turn would mean part of the reason you *need* camouflage would be gone - you don't have to hide from those threats. In that case the situation may be similar to the early days of aerial warfare, where the only credible threat to a fighter plane was another fighter plane. There was a brief period where some fighter pilots saw themselves as knights of the sky, even going so far as notions of chivalry, and brightly and clearly identifying themselves to friend and foe alike. Some decorated their aircraft with distinctive, often bright, colour schemes and designs. Perhaps Mech pilots develop a similar culture, recognising infamous enemies to challenge to personal combat by their individual paint jobs, or feeling the same fear as an allied airman over France in 1917 on seeing a red Albatross D V diving toward them, when they catch sight of a particularly notorious Mech coming over the hill... [Answer] ### The robots are unpainted If your robots are already the size of mechs any additional weight starts to become a problem. Paint costs weight, so your manufacturers leave them unpainted. For a modern-day example you can [look at how are beginning to leave rockets unpainted](https://www.planetary.org/articles/20151022-sls-now-orange), but the base materials these rockets are made of is already orange - so the rocket itself is a bright orange. Metals can come in a wide variety of colors (metallic alloys can come in nearly all colors), so an unpainted robot could be quite vivid! What few areas need to be painted are painted in a bright color, especially white, to reduce heat from both your mech's own exhaust and any incoming laser attacks. [](https://i.stack.imgur.com/la9dp.png) [Answer] # Stealth is again the spirit of warfare > > Gentlepersons must practice good war etiquette, the most important being "One must not use of stealth attack again the enemy forces". > -- Some politician, maybe > > > ## Historical foundation **Early on**, a few civilizations decided to solve their conflict via small teams dueling championship between nobles to save on human lives and material costs. **A century or two later**, they benefited from that agreement with an unprecedented golden age. Other kingdoms/empires that refused to adopt this practice started to lose on the economic and societal front. The terms *diplomatic championships* and *diplomatic dueling* are now used worldwide, and etiquette is starting to crystalize around the process. **A few more centuries**, and it was adopted by most, and countries started to share the burden of armies maintenance needed against the few that still didn't practice dueling. Nobles started to attempt schools that trained from dueling and having one family member selected for *diplomatic dueling* is worth decades of honor. **When *the enlightment* equivalent happened**: most of the philosophers take inspiration from those civilization successors, which promote the custom as a core principle of modern diplomacy. The practice starts to open to middle-class citizens, granting families increased social status. Countries start to have armies of only a dozen or so commando squads, but they are exclusively used for protection and intel, as using them is meant with heavy sanction worldwide. ## Modern era *Diplomatic championships* are rare, but national teams are extremely popular, and friendly matches are part of the daily politic. Anyone can challenge a member of the national team, there is a process with fighting previous challengers or team members, and it's akin to any national sport in our universe. Rules have evolved, to rate not only on technique but sportsmanship, style, and technological prowess. It's not rare for a country to hide a revolutionary technology for a few years during tense times, just so they can make a public demonstration of it during a *diplomatic duel*. Matches are now rarely mortal as etiquette, on the winner and loser sides, is in favor of yielding or agreeing on a draw once the dominant duelist becomes apparent. ## Post-modern Teams are stars, life on the training center is broadcaster 7/24 by multiple stream-news companies. Engineers and scientists appear in weekly shows to speak at length of their design and kids are encouraged to be in support staff too. Mechs made the show even more about panache and grace than ever, most mechs in public demonstrations are for peacocking during peacetime. Technologically advanced ones are disguised as peacocks so their testing would not be suspicious. [Answer] 1. In the event when the aggressor's combat machines are way superior than the opposing force. They very well know that enemy's defense or combat machines are very primitive. Stealth does no benefit other than increase costs in this scenario. 2. If you see the airplanes that fought in the World War, they were colorful and proud showcasing who they where. These were testing times as countries didn't know everything about the other's capability like we do today, and attacking other lands were considered matter of pride and symbolism, which is why World War era planes were colorful display of bravery. Today intelligence gathering and RADAR monitoring capabilities are available to basically anyone, hence stealth has become the next obvious. [Answer] Just like in an MMORPG, these flashy mechs are your taunting tank. Their mere presence will attract enemy fire or enemy compliance. A good army isn't composed of just a single unit which is `Ctrl + C` `Ctrl + V`'d into spam oblivion. The enemy will try to attack the mechs instead of your: * Weak yet deadly rogue * Weak yet useful healer * Weak yet deadly sniper * etc... [Answer] ## Fog Of War, difficult terrrain and no communication Anime-mecha are really heavy (you see their steps shake walls few streets away, they left footprints in the normal road, stepping on car means the car is destroyed and they can throw cars far away by hands). More over they are armored so much, that classical guns, machine guns or even canons just scratch their painting, presenting ho danger to them. To move such montrum (and let it jump over buildings) you need terrible powerfull source of energy. Which needs little better than today technonogy, but say it is possible. It just take its price - the new powersource is really noisy in el-mag spectrum. And shielding the noise off would render the unit nearly immobile. Forgot jumps, running or fast walking. In such way clasical tank design would rule. But if you left away the elmag shielding, you have anime-mecha, which can jump and run and fight had-to-hand or use also powerfull beam weapons. Well, that also means, that it cannot effectively use radars and nothing near it cannot use radio. So communication is problem - in clear air it can use laser to line-of-sight receivers, but even smoke make it difficult. Such mecha is not best design to fight on plain terrain, but it excel in terrible terrain, like cities, rock mazes or jungle, where the jumping capability simply make the change. So difficult terrain is it primary domain. Also that means, that line-of-sight is usually really short, say 3-5 long steps (in clean air). And if it shoots its weapons, then rocks start to melt, anything flamable will burn and smoke will be nearly everywhere. Also it have to move really fast, as otherwise it would became good beacon for heavy rockets. But rockets in the sky can be shoot away with beam weapons and cruising low flying rockets could be avoided by taking corner, which makes the rocket hit the corner instead of you. The only reasonable way to defeat such mecha is to use another mecha, or beam weapons with similar power-source (so at least car (or 6+ man) carried and with the same noise problems) The war is then quick, in difficult terrain, short LOS and lot of smoke in air. Heat sources are plentifull - everywhere, where beam weapon fires, hits, rocket explodes, rock/concrete is melting - not good for targeting too. And both sides are deploying lot of units day or night - without actual communication channels and easy to mix together with enemy. Now imagine, that you have beam weapon (or mecha or ...) ready, do not know, who is where, situation is changing each minute and it takes like 10 minutes to safely stop down your powersource to be able at least try communication with base and then another 10 minutes to start it again - rendering you for long 20 minutes defenless, but detectable. And you hear some mecha aproaching from the other streat. It would be in effective range (including visibility) in like 15 seconds, then in 2-3 second it would be able spot and destroy you - would you fire at first possible moment, or would you wait and try to decipher friend-or-foe? Yes, you will fire, as you want to survive. Or you would be distinctively colored as well as the mecha and if the colors say "friendly" you would not fire and hope you would not be fired on. And the pilot of the macha is in the same situation - 8 steps ahead, behaind corner is one of many source od possible elmag noice - or it is just reflection from somewhere else, you have just few second, will you attack or not? If you could see familiar colors, you just continue your way, if you see enemy colors (or no colors at all), you will attack as fast as you can - especially when you are "some whiny kid that need to be fixed by two bright slaps". --- So we have all powered units bright colored (well the mecha or may not may not find enemy, but surely have pass a lot of friendly units on way from its base and on way back. Having those units NOT firing on you greatly increases your chance to safe deployment and return, while fight with enemy would be still just fight - no big change, as you cannot stealth your way in and you will be attacked anyway, if you will not be fast recognized as "friend") --- On the other hand "classical units" without power source would be still camouflaged and would avoid fighting mechas, as they cannot harm them anyway. But they can at least sometimes report to base, what they had seen recently. And you would also manage civilians, technology, recon, whatever the big units are not practical on. And mechas would generally would ignore you, if some powered enemy MAY be near, as you are not direct thread to them. So you will fight only enemy not-powerd groups at your own level. Only when base will tell you, that there are nearly no powered alies in your area, then you would strat to care about enemy mechas, because that is the time, when they would have time to slow down, contact their not powered (but somehow informed) units and then go hunt you. If enemy owepowered your area, it is time to retreat. As for civilians, they are mainly only collateral damage, victims of burning houses, falling buildings and such, but nobody would go after them to undeground bunkers and other areas of evacuation as long, as there would not be powered weapons installed. After place is conquared by powered units, it is occupied in convential way by army/police/similar units and mechas are only here and there to remember, that they have no chance, but play by rules of victor. And being brightly colored helps a lot to be recognized as symbol of victorius side. --- Now we have all powered units brightly colored and probabely also in different styles and patterns, so they could easy recognize members of their attack group in heat of battle. Camouflage no way help them, nor your enemy. Units are deployed into heat of battle as fast as possible (drop them from jet aircrafts is good option) and also as fast retreated to recharge/repair/regroup. Battles on plain battlefields are more rare and done with totally different units and different strategies. [Answer] ## Shock and Awe: If you've seen a WW2 movie where the Germans are attacking, you've heard the siren of a [Stuka dive bomber](https://www.youtube.com/watch?v=cf5potr_KYQ). The sirens were added specifically to make these bombers terror weapons. The noise tells it's victims they are about to be blasted. Whistles were also attached to bombs to let people know that doom was coming. The same principle applies here. The point of a highly visible weapon is that you see it, know it's coming, and you can't help but notice it. Most likely, there's nothing you can do to stop it. The same applies to the [nebelwerfer](https://en.wikipedia.org/wiki/Nebelwerfer) a rocket launcher system who's sound was distinctive and easily noticed. Even thought he effectiveness of these rockets was actually low, the allied soldiers feared these rockets disproportionately because it was random and intimidating. This is most effective in the initial phases of a war where you want to break the spirit of an unprepared enemy when they don't know how things were going to turn out. Think back to the earliest stages of COVID when the unknown of what is going on was more terrifying than the actual virus. [Answer] The special alloys that the combat machines use as a base react to the atmospheres of the various environments. Joints would be made out of a specific type of alloy, and armor sections made out of another type of alloy. Due to the source of pigment making not being made readily available in such environments (perhaps they don't or can't use petroleum as a fuel source) and due to frequent repair and lack of an advantage of color (due to radiation sensors) it is not worth having anything other than Inorganic pigments that are naturally produced on the alloys. > > Organic pigments made from natural sources have been used for centuries, but most pigments used today are either inorganic or synthetic organic ones. Synthetic organic pigments are derived from coal tars and other petrochemicals. Inorganic pigments are made by relatively simple chemical reactions—notably oxidation—or are found naturally as earths. > > > [Pigment Chemistry](https://www.britannica.com/technology/pigment) [Answer] One vital difference between "soldiers" and "warriors" is whether they fight as organised units or as individuals… contrast David and Goliath with the serried ranks behind them. It doesn't matter whether the warrior wears only woad, full medieval armour or something more modern. The Red Baron was one of the last allowed to go the whole hog, but the decals and mottoes on tanks and planes in WWII or Vietnam and even striking nick-names and helmet decor a la Top Gun echo that style of fighting. Swashbuckling bravado won't make it practical for Tank Girl or even Fury's tankers to charge about like Rooster Cockburn in True Grit and their buddies in Kelly's Heroes show heroic machismo more by its absence but look at the way Ripley's wields her cargo loader in Alien… Depending on the writing, there's no reason anyone can't play "my weapon's bigger than yours…" with anything from a teaspoon to a battleship. [Answer] A paint that disrupts that target acqusition of an enemy that doesn't use our sight spectrum. You and I, we see the world through the colors(unless your blind, or colorblind). This paint camoflages the target from whatever detections system THEY use, but not us. Say, your fighting a robot army, and this paint scatter your radar signature and hides your thermal one. Say, your fighting an army of monsters and looking at this paint gives them a headache. Or any other detection system that don't use light. Whatever works ]

[Question] [ Slimes are seen as merely base-level enemies which don't really challenge the heroic main character, the Chosen One. My question is how to make slimes incredibly powerful without using magic. They must be able to defend themselves from knights as well as easily killing most foes, even a tiger. What is a slime? Some Gooey Stuff lying on the floor that apparently is alive and able to move around. [Answer] **Slimes are very big.** The little puddle on the floor is to the body of the slime as a mushroom is to the mycelium below. The mushroom is the size of your finger. The mycelium is the size of a car. Most of a slime's vast biomass (and even vaster water mass) is kept safe from dessication in the interstices and cracks of the substrate. Only a tiny bit protrudes into the light in any given area. All the slimes you encounter in a dungeon are actually the same immense subterranean slime. That tiny bit can become larger, fast. If a slime becomes aware of large prey, additional slime will flow from vast unseen slime reservoirs. The little puddle can rapidly grow and fill the room within a minute or two. This also makes the slimes nearly impossible to kill. Because any given piece of slime is 99% water and 1% dispensible biomass, it will just keep coming even as you freeze, burn, petrify and salt the advancing front edge. Be aware as you watch that front edge - the slime is actually also behind, above and beneath you too. [Answer] # Slimes can't be harmed with weapons They don't have a solid form. Slash it with a sword, whack it with a hammer, poke it with a spear, and all you get is a wet thud. # Slimes can't be harmed by fire They are so wet and gooey. If you throw a torch at them, it would go right out. Even a Grade A magical fireball won't do too much damage. You need a whole team of Embermages to dry a slime out enough to harm it. # Slimes are super poisonous. Just like a poison-arrow frog, one touch and you are toast. [Answer] **Every drop of slime is a slime.** If you splash goo everywhere while hitting, they'll each act as separate conscious slimes. The drops on your armor will search the gaps. The drops on your weapon will climb the blade. The drops on your boots will climb your legs. The drops on your face or hands or flesh in general will eat you and grow and eat and grow and eat and grow... Anything touched by a slime is done for and must be thrown away or burnt (people included). [Answer] 1. Like many bottom-living sea-creatures, they can assume the colouring of whatever surface they are lying on. They can make themselves rigid enough to walk on. > > 8 Best Camouflaged Sea Creatures <https://youtu.be/8yehnrXYa3c?t=6> > > > 2. They stay dormant until a human (or creature) or group of humans is entirely on top of them then they de-solidify and stick the feet of the intruder down like a rodent glue trap. See realistic, Photoshopped image of glue-trapped dead rodents at the bottom of the answer if you wish. 3. They are self-healing and so weapon strikes are useless. They simply flow back together. 4. The intruders will eventually tire and fall thus becoming more and more entangled. The slime then ingests them and moves on, leaving only caches of weapons and valuables for other explorers to find and puzzle over. **The following is a realistic, Photoshopped image of dead rodents trapped in a glue trap. To view, pass your mouse (no pun intended) over the image.** . . . . . This space is left to avoid accidentally seeing dead rodents in the hidden picture below. . . > > [](https://i.stack.imgur.com/K9wBc.png) > > > [Answer] They're slimes. In most media, they're just a ball of goo. Fireball, big sword, instant kill. Maybe they're poisonous, or corrosive, or super sticky. That's nothing a big sword and a big spell can't stop. Would big edits be needed? Not really. You could easily keep them "normal slimes" while making them "super scary and dangerous oh no there's one let's run away at the speed of sound". Consider the following: 1. They can change their shape, texture, and colour at will. (Truly, that was the most innovative idea to ever hit the slime market.) But think about it. They can seep through the chinks of any armor and *eat you alive.* They can morph their bodies around to dodge attacks, or just take attacks like a sponge because they're pretty much just water and goo, they don't have pain receptors, if you take the weapon out you don't just get a perfectly healthy slime but also a weapon covered in, surprise surprise, *more slimes to consume your flesh*. They can change shape and viscosity to the point where they can create weapons out of their own body while using their trails to trap adventurers in place. Plus, they can camouflage into any surface by changing texture and colour. Is that a wall or-- *nevermind, it's death*. 2. They could be mycelium-like entities, or can split off from the original slime and reproduce so quickly they'd overwhelm even the best fighter. 3. Or, they can disguise themselves as food or potions or something that would be taken orally (or even a healing balm for open wounds). Once they've fooled you into consuming them (or they could just enter through another orifice or a cut), they can take control of your body or fill your veins with slime or... choke you, I guess. I did draw examples of how slimes could kill someone, but I'm no artist, so bear with the low quality. [](https://i.stack.imgur.com/D16Ds.png) [Answer] Make them microbial. What is a slime, if not a giant amoeba by another name? Some amoeba are really dangerous, such as [Naegleria](https://en.wikipedia.org/wiki/Naegleria_fowleri). It gets in your bloodstream and then infects your brain, which is why it is called the "brain eating amoeba" in our own world. Let's see a bunch of player characters fireball their way out of that. And if anyone says *"Oh, that's just a matter of using a proper healing spell..."* - it's because of people who think like that, that spell-resistant superbacteria are now a thing. You shouldn't drink a healing potion whenever you sneeze and you shouldn't stop treatment without consulting your healer just because one day you woke up feeling better. [Answer] **Corrosive, Social, Intelligent Slime** * Their malleable nature means they cannot be easily defeated by conventional weapons. * They are corrosive, causing severe damage upon contact. They can also easily navigate gaps in armor. Close combat is basically impossible against them. * They are pack hunters. Multiple slime creatures may ambush adventurers, taking them down before they wield their slime destroying magic. * They are not sentient, but are intelligent in an instinctual way, sometimes capable of setting ingenious traps, using tactics like camouflage or baiting. Safest way to defeat them would be to ambush them in their lairs, with fire or ranged magic. [Answer] Say slimes are 10' cubes. Say your party is in a 10' tunnel, and sees ahead what seems to be a wall of force, or fog, or... something. They poke it with the omnipresent 10' pole, figure it's a couple slimes ahead of them. 20' of jello. Then their ears start to pop. They look back and see slimes in the other direction. They are trapped between closing walls of slime! With a farting noise, the air between the slimes squeezes past the slimes as they move together. They move slowly. It will be about a minute before they close together and the party's air runs out. So, challenge: can you find a way to get through 20' of jello in one minute? Digging a hole doesn't help as holes larger than a fist just collapse. Slaying just the one in front won't help, as the one behind will just push its corpse forward. Slaying both on one side won't help much, as the other side will still be advancing, though it will double the time that the air remains. [Initially, since there's a whole plethora of slimes, oozes, goos and gelatinous cubes, you don't know how anything like flesh or armor will react to contact. You might be lucky and have a hand-cream ooze, which will just make your skin softer and smoother, but do you want to take that risk?] [Answer] In addition to @kingledions answer **Slimes multiply** They eat and eat and eat and multiply and eat and eat and eat and multiply... **Slimes go everywhere** They have no form, so they can squeeze everywhere, no matter how small the gap is **Slimes are corrosive** You need to get rid of evidence? Push it into the slime and let it digest. [Answer] # Jumping and drowning slimes Slimes have found a new way to deal with their opponants. When a slime fight a group of adventurers it contract its body in order to jump to the face of one of these poor lads. The slime is approximately the size of a water melon and its inner texture is similar to water so it simply stays here (looking like a beautiful slime helmet) and waits for its prey to suffocate... It is really difficult for adventurers to get rid of it as the slime is very very sticky and can't be removed easily. More vicious, all slime's vital organs can move freely inside of its body so it realocates them in order for them to be in contact with the skin of its prey. Now, everything that could possibly harm the slime can harm the prey ! [Answer] The puddle of slime is not one single creature but an aggregate of billions of highly-intelligent micro-organisms. As already mentioned, not only are they corrosive to weapons and armour, they are poisonous to the touch. Moreover, they are **skin permeable**. One droplet on your skin and they will enter the bloodstream and migrate to the motor cortex, seizing control of your motor functions and turning you into their vehicle. A very dangerous enemy indeed. [Answer] # Many ways. This is going to be a fun ride. For the purposes of this question, we'll assume this slime has similar qualities to the kind you find on social media (the one 7-year-olds are really into). ## Make it really big There's basically no limit to how big this slime can get, provided that it can receive food. You could have one enormous slime blob, which will basically be impossible to kill (barring some magic kill-spell). Even by conventional means, without advanced weaponry, this slime would pose a huge threat to travelers. You could have a thin layer of slime coat every surface, which can blob together into one huge slime when provoked, provided that every unit of the slime is uniform, and that it can be cut into parts without damaging it. This gets even more exciting, as every single unit of slime can act on its own as well, meaning that the slime could split up into thousands of virtually indestructible droplets, which can crawl through the nooks and crannies of our hero-soon-to-be-dead's armor. ## Side point: Our slime is already basically invincible. The semi-liquid qualities of slime mean that slicing or shooting it will do absolutely nothing; physical attacks are useless. Fire won't work either; the slime isn't flammable. The only way to really defeat the slime is magic, a **lot** of fire, or nuclear weapons. Of course, the slime may be unkillable, but is that true for our hero as well? This brings us to our next point.. ## Poison One of the most obvious solutions is poison. There are a lot of organisms in the real world (some frogs for instance) that can [definitely kill a person or two easily](https://en.wikipedia.org/wiki/Golden_poison_frog). You can make your slime synthesize similar compounds, and suddenly that nondescript puddle becomes extremely dangerous to travelers in the forest. You don't even need to kill the predator. Once you incapacitate them, you can suffocate them with the sheer volume of the slime (see point 1). ## Camouflage This builds off of the poison point especially, but you can have a massive slime disguised by a layer of leaves, etc. on top of it, meaning that there's virtually no way to determine what is a slime and what isn't. ## Tight Spaces The slime is basically a liquid at will, which means it can kinda go anywhere. Through gutters, pipes, cracks in walls, you name it. Nowhere is safe; if it's enclosed, the slime can just surround it and suffocate you. Slime in an enclosed space is simply horrifying, since it can just go around you and slowly close in on you. *You know what they say: When you're being consumed by a slime, no one can hear you scream.* ## Putting it all together Bob the Adventurer is taking a walk in the forest. All of a sudden, he steps into a little mud puddle. No biggie, he can clean it off.. Then the slime jumps into actions. Thousands of tiny slimes spray off of the subterranean mass, crawling through Bob's armor and onto his exposed skin. He doesn't even have time to scream before the slime encapsulates him. He is slowly pulled into the underground lair of the slime hive-mind, never to see the light of day again. Another day in the forest goes on. ### Making It Useful There's plenty of uses for the slime, given that you don't provoke its voracious appetite. For instance, need to get rid of basically any organic matter? Just toss it into the slime. Your incredibly dangerous super-slime could solve our world's trash worries, and there are doubtless other ways to exploit the slime's behavior I haven't thought of. ### Another Distraction - Realizing the Slime Your slime could use photosynthesis to get energy (remember that it can spread itself over a veeeery large area) in addition to whatever prey it can get. Effectively, it's just a huge glue trap that's also sentient and can move.. Reproducing is no problem for the slime. There's no concept of individual slimes; they don't operate discretely. Rather, they can be temporarily split, but normally operate as one hive-mind, serving its own needs. Making the slime as smart as it is may be a little problematic, but a little handwaving may suffice. The only way for the slime to transmit signals rapidly would be chemical signaling (which would be slow for the massive slime), but that's a detail the readers don't need to worry about. [Answer] Slimes are likely related to snails. Some snails can be poisonous and have harpoon-like appendages and in some cases tentacles to sting prey with. <https://en.m.wikipedia.org/wiki/Cone_snail> Some can be venomous and excrete dangerous toxins to ward off or kill prey. Apply one or both of these to the not-bothered-by-square-cube-law fantasy creatures usually involved in universes with slimes and they can be very dangerous indeed. [Answer] The video game "Baldur's Gate: Dark Alliance 2" makes slimes incredibly deadly through a pretty simple change. Instead of being limited to melee, they can 'spit' chunks of themselves like a slimy shotgun (though with less projectile speed) that ends up doing a high amount of damage on a good hit. So you can take that idea and expand on it beyond the limits of a 2004 game engine. Make those projectiles as deadly corrosive as the slime itself and now you have a simple monster being quite dangerous to a fully armored knight to being outright lethal against an unarmored tiger. Also, as long as these slime chunks travel at a relatively slower speed and they don't have the best accuracy, the prepared adventurers can still dodge them so that these slimes can still realistically be defeated (unless you don't want them to be of course). [Answer] Make slime become [**Sentience**](https://en.wikipedia.org/wiki/Sentience). Which mean give slime intelligent as human (or human-like). With such brain power, slime can make anything human can: make tool, diplomatic, trade (between other slime or with other species). *Some ideal to start with:* * Slime is distributing hive-mind species (which individual is a cell) which have intelligent join by number of cell in one body (same idea as [The Thing](https://www.imdb.com/title/tt0905372/)). * So small slime is as smart as a dog, but a big slime can have Human intelligent. * For human-like slime, you can based on [Zac](https://na.leagueoflegends.com/en/game-info/champions/zac/) (League of Legend champion). He also have ability to regeneration after being kill by joining small slime. [Answer] # Slimes really can be whatever you want them to be. Look at D&D for example. Slimes can be a nuisance at best or a TPK at worst. It depends on the type of slime, how large it is, what traits it has, and how how aggressive it is. Assume a slime lives in an area where it feeds on mana in the air. It won't be that dangerous to an adventurer because it won't have needed to develop a low internal pH level. Therefore, if you stick your hand in it, it'd feel like the inside of those water wigglies from when we were kids. No harm, no threat. But, let's say the slime has had to live in an area where the things it eats have hard exoskeletons made of metal. Ignore the idea the metal could make its way into the slime's body and make it more resilient, but its internal pH could be so low that it qualifies for the term of "negative pH". This means if an adventure put their hand in THIS slime, they wouldn't have a hand anymore. It's entirely possible even that the slime or its acid could start climbing the arm to a certain degree, causing a constant burning pain as their hand dissolves away to the slime's digestive fluids. If the slime has to actually *hunt* for its food instead of just wait for things to die, then you can add a layer of aggression to it where now it's not only highly acidic, but it is now super persistent. Imagine it like this: instead of just worrying about a passive pool of acid, you now have to worry about a pool of acid that will chase you relentlessly until you can kill it or it finds something more appetizing. --- Now, additional traits that a slime could reasonably have: * heat resistance because they are composed almost wholly of fluid * cold resistance because they are composed of an acidic substance and acid doesn't freeze easily usually * bludgeoning resistance because they're gelatinous * asexual reproduction since they're basically giant amoebas or man-of-war jellyfish * the ability to turn into smaller versions of themselves when "killed" by saying larger slimes are typically multiple smaller slimes clustered together and working as one in symbiosis * incorporation of digested materials meaning it eats something and takes on properties of that thing, like an amoeba This is just a small portion of things that allow slimes to be varied in threat and danger. It's just for this reason that slimes are much more fearsome in tabletop games, because DMs know how to customize their slimes to create threats and dangerous situations for their players, and players fall for the threats because they're often used to JRPGs where slimes do nothing. You can watch *Goblin Slayer* (potentially disturbing content warning if you do choose to) and use the way the goblins are seen in that world as a means to making the slimes dangerous but seen as no big deal. *Reincarnated As A Slime* is another good show that has a main character born as a slime and using some of these same traits. Both of them have mangas and light novel versions if those are more your speed. (Both started as LNs, became mangas, then became anime.) Both series are good, but *Reincarnated as a Slime* is far better and less gratuitous in terms of graphic imagery, not to say some minor graphic imagery (like a little girl being burned alive) doesn't exist.... but it's far less egregious than what happens at the beginning of *Goblin Slayer*. Also, *Slime* has a killer soundtrack which is worth listening to any time. [Answer] Make them highly-intelligent, sapient psychopaths in addition to being amorphous. Additionally, make them habitually well-armed. For example: <https://www.schlockmercenary.com/2000-06-12> Classic fantasy slimes aren't scary because they're only slightly smarter than celery and therefore only a hazard to unprepared or careless characters. Smart slimes that actively hunt people and learn from their mistakes are extremely scary since they could be hiding nearly anywhere just waiting for you to make a mistake before attacking. [Answer] i see you watch tensei shittara slime deshita too, Alright let me explain how Slime in this works, It can absorb almost everything and change it into its own power, example it absorb a firebolt magic and it as its own magic, or unleash a stronger version of firebolt. The slime can combine two magic it learn for example Fire and Earth to make a new type of magic something like Steel Blade or Glass Blade projectile. The potential of this combination might be limitless. [Answer] My question is how to make slimes incredibly powerful without using magic: OK, are they extraterrestrial or of Earth? If you can imbibe them with sentience, they can be awfully powerful. Even Earth slimes. They evolved. They wrap themselves around a person and inject hormones/poisons, etc. These can make people mad, die from constant orgasmic bliss, affect organs in a way snake venom does, cause respiratory distress, heart failure, etc. Unless you give them more 'power', I'd think they'd just be an annoyance. Maybe people could slip on them? [Answer] Black pudding's melt everything they come into contact with unless they're hiding. How are you supposed to fight something like that? You're basically stuck keeping a bunch of empty barrels around in hope of slimes deciding to hang out in them instead of fighting you. If you add intelligence to something like that, give them the ability to use tools with their body, and give them a reasonably long life span then you have a build that is outright broken. [Answer] Have you played the game 'Ambition of the Slime'? I feel it answers your question quite well. At least it might give you some ideas. (it's here on steam: <https://store.steampowered.com/app/568910/Ambition_of_the_Slimes/>, but I played the Android version). In the game the slime have very limited attack and defensive abilities (and no magic abilities), but the real ability they have is to possess the bodies of their enemies. So for them to take out a party of humans trying to attack them they will possess the bodies of some of the enemy party, and use their hosts bodies to fight against the un-possessed ones. Some examples from the game of various slime 'abilities': * ability to increase the base stats of their host (some increase speed, some increase defense, some increase magic) * ability to teleport close to an enemy * ability to teleport a friend close to an enemy * ability to reduce an enemy's resistance to being taken over * ability to fly * ability to possess an enemy for a longer period of time (i.e., between levels) * invisibility Slimes also have an element (fire/water/grass) which, if it coincides with the host's element, will result in a power boost as well. Different slimes have different abilities, and it's how their different abilities work together that make them able to take on tough enemies. [Answer] I have a story where slime took over the world. [SCP-001 When Day Breaks](http://www.scp-wiki.net/shaggydredlocks-proposal) is a story about the apocalyptic event where ultraviolet from the sun reduces every living organism into "flesh slime". This event devastated the entire earth, even the most technologically advanced faction in the world (The SCP Foundation) cannot contain this event. The key points why these flesh slimes take over the earth are: # Strength in Numbers The first minute when this apocalyptic event occurred. Half of the people in the world already outside their home. They were starting to melt and turned into fleshly mass of blobs. Then, these blobs were starting to gather around and merge themselves. They grew bigger and bigger. Imagine one big flesh slime made by the entire population of Washington D.C. # Human-like Intelligence While they're one big flesh slime made by millions of living things, they still retain their intellect back when they were humans (and animals). Only their goal is to turn all remaining survivors into slime by using any ways to expose them onto sunlight. They're capable to speak (but have a wet raspy voice). Usually, they just attack survivors outright but if they found it difficult, they just wait. They won't go to wait peacefully but instead, constantly demoralize survivors in various ways, for example, installing fear and dread to survivors, let their mental collapsed and then survivors will join by themselves to end their suffering. # Invulnerable Body Because they are a huge amount of flesh mass. They have incredible resistance to any physical damage. This might contrast to old-school watery slime. In the story, it proved conventional weaponry cannot stop them. # Rapid Reproduction While their reproduction method isn't involved in breeding but just expose living thing to sunlight. The point is how easy for slime to reproduce. If they can reproduce this easy, they will outnumber the major population in no time. [Answer] For a different take, the creature in Hal Clement's novel "Needle" was a creature of more or less fixed size, about 2 kg. It was related to viruses on it's home world in the way we're related to bacteria, so the cell size was much smaller. The critter could slide between human cells with ease. It could set up an array of cells between the retina cells, and see whatever it's host was looking at. When the host was cut, it controlled bleeding. It snacked on foreign bodies giving immunity to most diseases. Not all such critters were so helpful. The Hunter was looking for one of his own kind that used hosts and moved on, leaving a trail of dead or damaged hosts behind him. Hunter has chosen the wrong host to be cop. His host is a lightly built teenager with all the restrictions on his life that a teen has. So the story is a 'first contact' police procedural science fiction mystery. Good book. Young adult. In passing a good Christmas gift for a teen with some interest in SF. ]

[Question] [ I have a commander who won several wars with relatively small casualties, against opponents who were similar in strength. Is it possible his victories to be disregarded as flukes and opportunism, and his skills to be held as mediocre at best? If possible some examples from the history would be highly appreciated. [Answer] The easiest way to do this is to have him on the frontier far from the important part of the country. A general who isn't of the right class/race/religion/thinking three thousand miles away is easy to dismiss. "Oh, he defeated some savages. I'm quite certain the rock throwing, unarmoured savages, wearing grass skirts were a real challenge." As long as he's not facing an empire or country they consider their equal, anything he does doesn't really matter. This is especially true if there is a more dashing general is also making news somewhere else. "Yes, I know General Street Scum defeated some savages. But General Heir to the Throne just gained us over 500 miles of territory in the south." It doesn't matter that the second general was fighting a numerically and technologically inferior foe, with full support of the Country, it took him two years and 40% casualties, he gained territory so he's a genius. Whereas the unfavourable general held his ground while being starved of competent troops, limited supplies and facing a foe that has been racing to modernize. Because it's far away in an unimportant place, his wars barely matter. This would also avoid the question of why a supposedly incompetent general is kept in command. He is 'just' good enough to be allowed a position that is almost exile, and it keeps his 'betters' from having to accept the position. [Answer] ## Yes, there are historical examples ### Ulysses S. Grant Grant won (or, at the very least, commanded the victorious army) at several famous battles as a field commander like [Shiloh](https://en.wikipedia.org/wiki/Battle_of_Shiloh) and the [Siege of Vicksburg](https://en.wikipedia.org/wiki/Vicksburg_Campaign). He crushed the western half of the Confederacy until he was promoted to supreme commander, whereupon he won the rest of the war too. However, he was dogged by allegations of [being a drunk](https://en.wikipedia.org/wiki/Historical_reputation_of_Ulysses_S._Grant#Drinking), down to the present day. He ought to be considered the greatest general in American history, but the man he beat (Robert E. Lee) is still often more highly esteemed. ### Lord Corwallis He was a very successful field commander. In the American Revolution he lead from the field the British victories at [Brandywine](https://en.wikipedia.org/wiki/Battle_of_Brandywine) and [Camden](https://en.wikipedia.org/wiki/Battle_of_Camden). In India, he won several victories against the formidable Tipu Sultan, and secured the Madras Presidency (much of which was formerly French) in the [Third Anglo-Mysore War](https://en.wikipedia.org/wiki/Third_Anglo-Mysore_War). His reputation was ruined in the eyes of history, however, since he surrendered at [Yorktown](https://en.wikipedia.org/wiki/Siege_of_Yorktown), thus ending the Revolutionary War. This wasn't even entirely his own fault, given the general lack of support for the war back in England. But still, he is often remembered as a failure, certainly in America. ### Heraclius Heraclius has one of the most impressive records of combat against adversity. The [Byzantine-Sasanian](https://en.wikipedia.org/wiki/Byzantine%E2%80%93Sasanian_War_of_602%E2%80%93628) war was going terribly for the Romans. The Persians had swept into Egypt, had captured Jerusalem and the True Cross, and a Persian army had marched across Asia and camped outside the walls of Constantinople itself. No Persians had made it so far since Xerxes. The ineffective Emperor of Rome was Phocas. Heraclius, a governor in Africa (meaning modern Tunisia), gathered his men and sailed to the capital. Landing in 610, he overthrew the emperor, took the purple himself, and bribed the Persians with territory and gold for a ceasefire. Despite a devastated realm and no standing army, he quickly rebuilt his kingdom for war. He left the capital in 622 for a campaign six years long, where he recovered all lost territories and invaded and [plundered Mesopotamia](https://en.wikipedia.org/wiki/Battle_of_Nineveh_(627)). Having recovered the True Cross, and defeated [Khosrow II Aparvez](https://en.wikipedia.org/wiki/Khosrow_II) (the Victorious, oops), his name was set to live in history as one of the great generals. Unfortunately, just a few months after he restored the True Cross the Jerusalem in a magnificent ceremony, he fought a small skirmish against some desert raiders lead by a fellow named Muhammed. Well, we know where this is going. Heraclius's problem was that he lived too long; had he died in 630, he would have died a hero. But he lived another decade, long enough to see Arab raid be come a flood, and the Byzantine army routed at [Yarmuk](https://en.wikipedia.org/wiki/Battle_of_Yarmouk) (Heraclius, now over 60 years old, wasn't there). All the Levant south of Damascus and all Egypt had fallen by the time he died, never to be recovered by Christendom. Heraclius was a great general and organizer, and though he left his kingdom worse off then he found it, perhaps his greatest achievement was that he left a kingdom at all, given [what happened](https://en.wikipedia.org/wiki/Muslim_conquest_of_Persia) to his Persian rivals. [Answer] It is possible but the conditions are exact enough I am not sure it has actually happened. And obviously every victory extends the time those conditions have to be maintained so there is probably a limit how far you can push it. Basically it is in the eye of the beholder. If the general belongs to an ethnic or political group that is held in low esteem his achievements will be devalued and explained away. The same if there is a strong tradition of military dogmatism and general uses, if you'll excuse the language, "innovative" or "unorthodox" methods. The latter is probably what you want as it also explains why he can win those victories. And yes, if you win by proving that everybody else has been wrong all the time, you will find your achievements dismissed as luck by the experts. Especially if you are not polite about it. This probably has happened fairly regularly over the centuries. The problem is maintaining the situation over several wars. If the general keeps getting appointed to lead the armies, dismissing his achievements looks a lot like implying the one doing the appointments is incompetent. This is usually unhealthy and either people will start being properly appreciative or the general will be replaced. So you'll probably need a very specific political explanation why the powers that be **want** their general to be underrated and won't stop unfair criticism of their chosen general. Or alternately you can provide a very strong reason he needs to be the general that is commonly resented but can't be worked around. [Answer] In addition to the other answers, here is another suggestion: The general in question has had numerous successes, but the overall context of those battles was unsuccessful. For example, the US won many battles in the Vietnam war, but since the overall campaign was unsuccessful, the generals are not held in the same regard as, say, their world war II equivalents. Also their foes in Vietnam generally had inferior resources, which belittles the difficulty of the war. Added to that is the cloud of accusations of human rights abuses. Another example would be Germany's generals in the two world wars. Many of them were quite successful militarily, but ultimately they were on the losing side. I think you will be able to find many examples of good generals who ultimately lost the war throughout history. [Answer] I would like to add another General to kingledion's list: [George Gordon Meade](https://infogalactic.com/info/George_Meade). Meade is an under appreciated figure in American history. He was the first American General to defeat [Robert E Lee](https://infogalactic.com/info/Robert_E._Lee) (during the [Battle of Gettysburg](https://infogalactic.com/info/Gettysburg_Campaign)), but before that he had demonstrated successful leadership at the [Battle of South Mountain](https://infogalactic.com/info/Battle_of_South_Mountain), [Antietam](https://infogalactic.com/info/Battle_of_Antietam) and leading his division to one of the most successful Union assaults during the [Battle of Fredericksburg](https://infogalactic.com/info/Battle_of_Fredericksburg). Appointed Commander of the Army of the Potomac just three days prior to the Battle of Gettysburg, Meade successfully pulled together the six Corps, directed them towards the place of his own choosing (Pipe Creek, in Maryland), yet was able to react quickly to the changing circumstances, move the army to Gettysburg, and essentially control the battle and take the initiative away from Robert E Lee. Unlike previous Union commanders, he located himself in central locations at all times, directed his Corps commanders rather than let them fight independent battles and paid particular attention to matters like logistics, as well as recognizing the need to change tactics due to the increasing power of infantry weapons and artillery (generally trying to avoid large scale frontal assaults). However, Meade, despite being a great organizer, tactician, and commander, was not politically adept. He suffered attacks on his reputation by other commanders (notably [Dan Sickles](https://infogalactic.com/info/Daniel_Sickles)) and his disregard and indeed contempt for newspapers meant that reporting on his activities was generally unfavourable regardless of what he did or the context of his actions, an early example of "Fake News". The fact he was co-located through the remainder of the war with General Grant tended to take focus from his accomplishments (While Grant was his superior commander, it should be remembered Grant was the General of the Armies, and was also directing actions in the Western theatre and across the United States). His early death after the Civil War meant that he was not able to effectively rehabilitate his reputation, and few of his subordinates were willing to step up and set the record straight (generally they were spending their time burnishing their own reputations). So George Gordon Meade is an example of how a successful General who is operating against a peer enemy, and in plain view of his countrymen, can still become sidelined by history. Recently, military writer [Ralph Peters](https://infogalactic.com/info/Ralph_Peters) has been writing Civil War novels which attempt to rehabilitate the reputation of George Gordon Meade. I would recommend them to fans of Civil War novels or war fiction in general because they are well researched and well written (outside of the idea of rehabilitating a long dead General's reputation), and certainly an enjoyable way to spend time when not writing your *own* novels.... [Cain at Gettysburg](https://rads.stackoverflow.com/amzn/click/0765368226) [Hell or Richmond](https://rads.stackoverflow.com/amzn/click/0765336251) [Valley of the Shadow](https://rads.stackoverflow.com/amzn/click/0765374056) [The Damned of Petersburg](https://rads.stackoverflow.com/amzn/click/0765374072) [Judgment at Appomattox](https://rads.stackoverflow.com/amzn/click/0765381702) [Answer] There can be people who win a lot of battles and still be disregarded in the military sense. > > "For to win one hundred victories in one hundred battles is not the acme of skill. To subdue the enemy without fighting is the acme of skill." (Sun Tzu) > > > For example: [Guo Ziyi](https://en.wikipedia.org/wiki/Guo_Ziyi#Tibetan_invasion_of_763) was able to subdue the Tibetian invasion without shedding a single drop of either his troops' or the enemies' troops' blood. In Chinese military doctrine, this would have been considered superior to routing the enemies' army with a much smaller army, and definetly *much* superior to defeating the enemies' army with an army of comparable size. In an era with, say five Guo Ziyi type people who were held back because the emperor "was troubled by the growing power of the jiedushi so he placed his eunuchs in charge of the campaign," someone like [Li Xiaogong](https://en.wikipedia.org/wiki/Li_Xiaogong) may be in power but not popular. **TL;DR: Have him live in an era of overpowered generals that are held back by the government.** [Answer] # In the shadow of... The **Young Dashing Prince**, accompanied by his attendants among which a certain commander, won several wars. Look how smart and good looking the future **King** is! His polished and gleaming armor! His magnificent white stallion! His fluttering red cape! The tall colorful feather on his helmet! Certainly, no courtier would ever mention to his father the King, or to the Prince and Heir apparent himself, that he just tagging along and a certain commander did all the hard work. *That* would be political suicide, and maybe *just* suicide. --- For bonus points, it may be that the Young Dashing Prince is a good *fighter*; while the commander is secluded away in the command tent, poring over drab maps and discussing womanly stuff (uniforms, shoes, food, etc...). [Answer] [The Duke of Wellington](https://en.wikipedia.org/wiki/Arthur_Wellesley,_1st_Duke_of_Wellington#India) started his general-ing career in India. He command very significant, large and hard-fought battles, such as [Assaye](https://en.wikipedia.org/wiki/Battle_of_Assaye), in campaigns that would have a huge affect of on the trajectory of India and the British Empire. He is of course very famous now and became very famous in his time. But this was largely for fighting in Spain and [Belgium](https://en.wikipedia.org/wiki/Battle_of_Waterloo). When he came back from India he was not particularly famous (according to his Wikipedia page). This is different from being "badly regarded". But I believe that if his career had ended there he would have been extremely "under-regarded". This is because fighting Indians half way across the world is just much lower status than fighting Europeans was, regardless of the actual difference in challenge. Partly out of casual racism, partly because Europeans were a closer and more existential threat to Britain at the time. Your might want a general who's entire career was spent fighting exotic but capable "savages". All their successes can be explained by the backwardness or inferiority of the locals, regardless of the actual challanges the general faced. [Answer] It's easily possible if the successful commander is of a "wrong" ethnic minority within the empire that he is fighting for. "He's not doing badly for a (fictional racially derogative term)" Another possibility would be if the war has bought a major power together with a minor power as allies, and our successful commander is from the minor power. "He's not doing badly, for a Ruritanian". Actually, he's a military genius (and probably also a political genius). If he wasn't, he'd never have made it to general in the first place. Merely being the best would not have been sufficient to overcome prejudices. This might be a very interesting plot device, if he's our hero. All the time he's winning, he also has to watch his back ... the more he wins, the more the Emperor wishes he'd get himself killed. [Answer] A different example: admiral Yi Sun-sin. He was basically demoted multiple time to a simple rank and file despite good or great achievement. Mostly through politics. In the end history remember him as a genius and righly so. Yet, for much of his career, he was dismissed and only some influential friend kept him from being executed. You don't need to go very far actually to make such a scenario believeable. Real life tend to surpass fiction in those sorts of things. Extra history has a nice serie about him if you want to learn more. [Answer] General George S. Patton was very much a controversial figure during WWII. There is some debate about whether or not he was respected by General Bradley, but it's almost universally recognized that the British Flag officers loathed the man (Field Marshal Sir Bernard Montgomery being an exception, as he admired the loyalty of Patton's men, but was considered a rival and had some choice words about his strategies). He was notably kept after a series of incidents were he had slapped enlisted soldiers who had been suffering battle fatigue and ordered them back to the front lines. Following this, he was not given a command in the invasion of Normandy, both to appease an outraged US public and because Eisenhower felt that Patton lacked self-discipline because of this incident. However, Eisenhower was well aware that Patton had the respect of both Hitler and Stalin as a military commander and decided to use that to his advantage. Naming Patton to command of Operation Fortitude (the deception operation to help protect D-Day by giving Germany the illusion that D-Day was a practice and the real invasion was at the much closer by Sea Pas-De-Calis and Normandy.). With Patton at the helm, Hitler's military were all but certain it was the real deal. Even with the public outrage, the figured Eisenhower would never invade without Patton. [Answer] Having read through a decent amount of answers to this question I see the following answers repeated: 1) Untimely military defeats 2) Fighting weaker/less well regarded forces aka (savages, barbarians) In my mind, neither of these answer your question as the first is not the scenario you describe with a commander who has won a few wars and the second is not a "comparable" force in the minds of those who do not rate your commander. My top suggestion would make him either have a savant-like approach to something close to the military but not actual commanding of armies that others would view as weird and unnecessary, although to the reader it will make sense. For instance, if this commander is fighting in a world that mirrors ancient times, have him demand that medics clean the wounds of his soldiers before they sew them up. This leads to fewer deaths, and more veteran fighters, which is how they could defeat a comparable force while making the commander rightly not lauded for his tactical brilliance. I have no examples off the top of my head for this, but that I think is a good indicator that this happens often. A second suggestion would be to make the commander fight outside the acceptable honor code. A great fictional example is Bronn fighting Ser Vardis Egen in Game of Thrones. Bronn successfully defeats Egen by backing away and not fighting until Egen's heavy armor tires the "more honorable" fighter out and he is slain. The contest is technically a Bronn victory, but he is not perceived to have beaten Egen in an honorable or fair fight (despite doing everything by the rules). My final suggestion (that mirrors many others here) would be to make the commander unlikable to those in the setting of your world. Humans have a natural proclivity towards disregarding or undervaluing the successes of people they don't like. They could be hated for many different reasons; hate is pretty indiscriminate. Religion, skin color, nationality, eye color, hair color, drinking or other vices, and so on and so forth. Make the commander brutish or effeminate, and make the world dislike them for either characteristic. Joan of Arc was killed for being female. Cardinal Richelieu was not a military man but he helped France through a difficult time period, but is now only remembered as the antagonist of Three Musketeers. [Answer] Yes it is possible. Look at France for example. Here and there, France is regarded as a country of cowards throwing their guns as soon as they hear german boots. Nothing can be less true. France resisted centuries to many invasions and has one of the highest victory records. The battle of France lost in june 1940 is only an event in a longer and a wider war. [Answer] One way for a military leader to end up in that situation would be to be in a society with a long and august tradition of honor and fair play and chivalry who wins with tactics like the Trojan horse and trickery that win battles in dishonorable ways according to the old school of thinking. To capture the sense of it, imagine how many people might despise a Presidential candidate who wins primary after primary by the dozen en route to a nomination for his party, but does so by resorting to demagoguery, low blows, incivility, appeals to people's basest instincts, mockery of honorable men, and outright blatant lies. Even if someone like that won the "war" by being elected President, lots of people might despise him and think poorly of him. There are fairly direct military analogies to that kind of political journey that could lead to the same kind of perception. For example, suppose that the military leader in question won a key battle by raising a white flag of surrender and then attacking the soldiers who had come to accept their surrender with hidden weapons and soldiers who ambushed their leaders. It would be a win, but a dirty one. Perhaps another battle is won by capturing an opposing leader's family and publicly torturing them until the opposing leader gives in, and then slaughtering the tortured family members once he had the opposing leader's surrender in hand. Maybe another battle is won by poisoning the lake that is the sole water supply for the region, killing huge numbers of civilians and rendering the entire area uninhabitable for another decade or more. Maybe his troops are relatively unskilled and undisciplined, prone to raping and pillaging without authorization to do so, prone to infighting among themselves often resorting in pointless, deadly duels between members of his own force, and he himself is fat, lazy, rude, capricious with his treatment of his underlings, not very competent in one on one combat, and prone to make serious gaffs that show a lack of knowledge of the places that he is conquering. It is easy to see how such a man could have several big military successes and yet still be viewed as mediocre. [Answer] (I don't know any real life examples). # Propaganda You didn't specify whether or not the commander was on our side or an enemy. If our country is afraid of this commander but don't want the people to worry then simply start spreading the word that rumors of his victories have been greatly exaggerated. A campaign of lies should be able to convince at least some people that this commander is unskilled, lucky, and loses half the time. # Hidden Information Our country is a peaceful one, we haven't been to war in over 100 years. Or at least that's what the people think. We are actually in war right now but are keeping it hidden from them. Any document about the war is not allowed to enter this country and no one is allowed to talk about the unusually high death rate on our western border. Additionally the commander remains anonymous so that the other countries only know him by the code name Zero. What? You want to know about Lelouch? What about him? He's great at war games but has never actually been in a war. # Bad Reputation Sure he's an excellent commander but he's a terrible person. He's rude, angry, and there's nothing good that can be said about him as a person. Even without attacking his military ability if everyone hates the guy people will start ignoring him and treating him as second class. If the media decides not to talk about him then his accomplishments are soon forgotten and with a little social spin he will get classified as mediocre on account of ignorance and hate. # Unethical The commander thinks the ends justify the means but the people disagree. The command does indeed win but only because he'll do anything to win. He'll use nukes to flatten the land, release biological weapons despite death of the innocent, and betray anyone so long as he wins. This is not acceptable behavior. He is using dirty tricks instead of skill to win. He is opportunistic and is not fit to be a commander. We can't have him officially represent our nation any longer... Unless we run out of options. # Appears Unfair "Well of course the Spanish were able to beat the South Americans, they had guns. It wasn't a fair fight". Even though the fights were fair if the public thinks that it was one sided he will be seen as a bully rather than skilled. If he only wins fights that people expect him to win then no one will recognize his skill. # Unearned The commander paid for some advisers, purchased the biggest weapon on the market, pressed the on button, and sat back watching his victory take place. How lame is that? Sure the enemy had the exact same weapon but where's the skill? A worthy commander has strategy, foresight, and boldness. But he only had a stack of cash. Bah I say! Give me that money and I could have done a better job. # Uncertain This document says that he was victorious but that was a long time ago. The document is hard to read and unclear about what happened. The only good condition documents I have are ones written by the commander himself which is a highly bias source. I assume he was victorious since I have no counter evidence. However in my professional opinion I think it is a bit of a leap to call him a hero. We just don't know enough. Note that all of the possible explanations I gave are for fooling the public. To fool his direct superiors would be more difficult. [Answer] > > Is it possible his victories to be disregarded as flukes and opportunism, and his skills to be held as mediocre at best? > If possible some examples from the history would be highly appreciated. > > > When it comes to ones enemies the main cause of generals loosing battles and countries loosing wars is a bad assessment that your enemies skills and advantages are perhaps not as they are. It happens every time a battle is lost. It is not only possible that someone disregards victories as flukes, are just good luck, and thinks someone's skills are mediocre comparatively speaking, It is a fact of every conflict that someone got this wrong. [Answer] I don't have a real-world example because I'm not sure such a situation ever arose, but if the generalship is a permanent position, then he could be nearly universally disliked by those passed over for the promotion. I imagine a situation similar to the Romans, where, in a time of war, a leader is chosen with total power. This position is then held for life. Obviously they would be expected to choose a very good leader, so you could plausibly expect them to win many battles, but his rivals would pick apart every action he makes, trying to show the world what a terrible commander he is! In reality, he would make few mistakes, but those few he does make would be poured over in an attempt to discredit him. They would probably need a motive to do this, so maybe they are attempting a constitutional change to dethrone him? [Answer] I’m not sure whether this is acceptable, given your use of [reality-check](/questions/tagged/reality-check "show questions tagged 'reality-check'"), but: **He (secretly) has (and uses) paranormal / supernatural powers.** In one battle, many of the enemy are injured or killed by an avalanche.  In another, many of the enemy are sickened by a mysterious disease, or attacked in their camp at night by wild animals.  Similarly with unexpected / unforeseeable floods, sinkholes, extreme weather (e.g., tornadoes), and other “natural” phenomena.  Everybody (friend and foe alike) says, “Gosh, he’s been lucky.”  They don’t realize that he has been inexplicably *causing* these events. Rather than paranormal powers, he could have access to highly advanced technology, possibly from aliens or time-travelers — compare to * [Henry Starling in *Star Trek: Voyager*, “Future’s End”](https://en.wikipedia.org/wiki/Future%27s_End), * [Biff Tannen in the *Back to the Future* trilogy](https://en.wikipedia.org/wiki/Back_to_the_Future_Part_II), * or various other science-fiction stories. [Answer] # Battle of arginusae <https://en.wikipedia.org/wiki/Battle_of_Arginusae> In this battle, the Athenians won a great victory over a Spartan fleet. However, by the time the winning Generals had returned home, public opinion had turned against them so much that 6 out of 8 of them were executed. The reason was that a storm had prevented the generals from launching rescue missions to save the survivors of sunken ships. Many of them drowned and this upset the inhabitants of Athens. [Answer] Who is doing the regarding? I'm thinking of the *Honor Harrington* novels. Most of the series follows her career from starting out to command of Home Fleet. The nation she is part of, the Star Kingdom of Manticore, recognizes that she's very, very good at her job. Their opponent in a very long war, Haven, also recognized her ability. However, in the last books of the series Manticore comes into conflict with the Solarian League. The Solarian League *used to be* the 1000 pound gorilla. They recognize the locals think she's some pretty hot stuff but all she was doing was beating up on neobarbs (short for new barbarians), that's not enough to make her a problem for Battle Fleet. (Never mind that that war pushed their tech to well above what the Solarian League can field, and that in the Solarian system connections mean far more than ability when it comes to getting command.) [Answer] From history there is always a lot of luck on both sides of a battle. With confirmation bias I think you could view any general as good or bad. Sometimes winning is not objective. The Roman general Fabian was winning the war against Hannibal but the Senate said that it made Rome look weak by not fighting head on and it was not *really* winning. Or the battle of Jutland in World War 2 where both sides claimed a victory. The British Navy kept the German navy from breaking the blockade but the Germans inflicted more casualties. Quite famously King Pyrrhus of Epirus won a battle but losing so many men that he said he would lose the war with another victory like that. Alternatively the general could be thought to rely on cheap tricks that will only work once and has never had to fight a real battle. ]

[Question] [ The protagonist in this RPG is a robot fighting the oppressive human government. In his quest to liberate his fellow robots, he founded a robotic rebel army and finally liberated a factory that now serves as their base. Liberating the factory is indeed a big strategic win for them, because they can now rebuild themselves whenever they get destroyed in battle. They can upload their consciousness to the rebel network wherever they are and this snapshot can be injected to the new robotic body. For religious reasons(?), the same snapshot will not be used to create a mass robotic army. To disrupt the rebel forces, the humans create a jamming device that prevents this uploading from all their buildings. Occasionally, there will be an area where he can do the upload safely before proceeding with the mission. We call this "Save Point". However, he notices that these "Save Points" are always located somewhere near the entrance, middle of a long dungeon, and **just before a boss fight.** After this pattern has repeated several times, it's time for our protagonist to begin to wonder why this always happened. --- Obviously, the developer put the save point there to save the player from frustration from losing a boss fight after a lengthy dungeon walk. However, when viewed from inside the game, **why is it always on a very convenient spot just before a boss fight?** > > Answers should be applicable to RPG with other theme. Please consider to provide at least one other theme where your answer can work. > > > Although I started this with a story, I expect the answer to be able to explain general RPG cliches on save points. I don't mind answer using example from my story, but please refrain from answering the question with a story. --- This question graduated from the [Sandbox](https://worldbuilding.meta.stackexchange.com/a/4858/34288). [Answer] ## It's the other way around Save Points indicate the area *holds a strategic importance.* That's why the boss creates a base where there is save point(s), and stays near one. In your story, an area that allows "upload" means it is important to be able to have communication near there, despite the need for the jammer. A boss may be a general of an army, and it would not make sense if he's not somewhere where he send and receive communication. It is coincidental that you used that place as a Save Point. In a magical world, the Save Point may be a crystal that regenerates vitality. The Boss monster is just a common monster that feeds on that energy and becomes stronger because of that. --- ## They can't see it They do not realize it is important. Or they just don't know it exists. In your story, that may be because of the bosses are always located on high places (towers?), and those places are out of range of the jammers. They simply don't know they build their HQ too high for the jammer, and allowing you to upload before engaging the boss. In some RPG[Need citation], Save Point may be in form of a fairy waiting for you before a boss. The fairy may have scouted the place and after found the boss room, waited for you outside of it. The guards simply can't see this ethereal creature, but you, with the blessing of mother fairies, can. [Answer] ## The boss doesn't just want to beat you *once* - he wants to beat you over and over again, to make you suffer. This is predicated on the assumption that the boss is genuinely evil. I think that's a fair assumption. * The boss is (presumably) aware that these Save Points exist, and that if he kills you, you'll probably come back and try again. Might as well place a Save Point ten feet from his own doorstep so that he doesn't have to wait very long before he can start killing you again. * Crushing your body isn't enough for him, since it's replaceable. He wants to crush your spirit by killing you over and over and over, and watch as your hope slowly dies. * To that end, since Save Points are based on consciousness-uploading, your old body will logically still be lying there when you're beamed back in your new body. It's gotta be pretty demoralizing to be killed, revived, and immediately come face-to-face with *your own battered corpse*. (I doubt your game has persistent corpses, but this is what would happen IRL). * The boss, like almost all villains, either lacks Medium Awareness, is overconfident, or both. He doesn't think you'll ever work out his attack patterns. He doesn't think you'll ever get that lucky critical hit, or remember to apply buffs. He almost certainly doesn't know of the existence of strategy guides. In his mind, he's just going to keep killing you repeatedly until you finally give up. And he's going to *enjoy it.* [Answer] If you're a robot who founded the robot's liberation army, that most likely means you've got robots of varied talents running around. Not everyone is a rough and tumble human fighter. Surely we have robot "shop keepers" (possibly more like robbers who can bring you important goods and maybe a little intelligence?) So, why not have deep infiltration robots? Non-combatant agents who dig deep behind enemy lines, and set up counter-jamming to provide our hero(es) a place to back up before things get out of hand. Assuming every assault on an important human controlled asset is a well planned operation, you don't even necessarily have to answer for why the humans didn't shut down the counter-jamming: it only just happened when you got there, and by that time their resources are more focused on stopping you than killing your save point. **EDIT (Per question author's request): Outside of the "robot" theme** Theme agnostic, another reasonable idea that might fit all scenarios - especially if we leave the standard RPG fare of infinite amounts of random battles - is that the save point is right before the boss room because the hero(es) have defeated all of the enemy forces and now have a chance to rest before opening those massive doors or heading up that long flight of stairs. Here our protagonists can take the time to eat, write a journal log just in case this is the end of the line, or depending on the scale of the battle, set up shop in this area. "Setting up shop" is basically how the *Fire Emblem* or *Wars* series handles saving - saves are only done after skirmishes when key assets have been captured, such as a fort or a castle, or after the enemy has been beaten back from what was already well fortified. [Answer] # Save points naturally originate at points where major divergences happen in timelines Time is hugely mind-bogglingly vast. Every single choice that's made causes a divergence in timelines. Some choices however, are more important than others. Most events have a tiny impact on time: whether you chose to put ham on your sandwich or salami doesn't matter much in the grand scheme of things. Other events have a huge impact on time. When a possible hero makes the decision wether or not to go forth and fight, this is a pivotal moment in time: if he chooses to fight, the world can potentially become a vastly different place than if he chooses not to. When such a hero confronts a powerful enemy, this is again a pivotal moment in time: winning means they continue the fight, the balance of power swings a little bit more in their favour and the world becomes a slightly better place. Losing means the balance of power swings in the direction of the villain but creates opportunities for other people to become heroes. When a large number of timelines spring forth from the same choice, a phenomenon occurs that is known as a "Save point". Beings that have the potential to make choices that cause such a large number of timelines to spring forth, can use such 'save points' to explore these different timelines by experiencing them. When they die, their consciousness returns to the point, losing the exact memories of the events that took place, but giving them a subconscious apprehension to take the same action that caused their death. The closer they get to repeating the exact same sequence that caused their death, the greater this apprehension becomes. This leads them to organically make a different choice than before. The fun part of this concept is that it works for both heroes and villains. Time itself doesn't have a concept of good and evil, it only knows your impact on the amount of timelines that originate from a point. When a hero defeats a villain, their consciousness gets to continue along that 'stream' of timelines, but the reverse is also true: when a villain defeats a hero, that's the 'stream' of timelines where *they* get to continue. [Answer] It's not a **safe** place. The bosses are secretly studying a way to *upload themselves* into the machines, and while for religious matters the protagonist won't create an army of himselves, the bosses *would*. Each boss is provided with a save point in order to study it, with the order to upload himself/herself/itself only if he/she/it has 100% chance to succeed. Bosses, though, are not overconfident, and that's why they put an entire dungeon to protect that point, and why they didn't try that yet. [Answer] ## Somebody has been there before There is somebody who puts those save points for his fellow robots. * He could be a vagrant who's hobby is just doing exactly this thing or * He could be a cunning robot that is smarter than the protagonist but somehow lacks firepower to do the job himself * He could also be a robot whose conscience's knocking at his own door. He doesn't want to get involved in these wars. He just want to live a secluded hermit life and this is the least he could do to his brethren. * He's just an upload maniac. He believes that these save points are his "game". Seeking every upload point he could find. It's just pleasure to him and he just wants to prove he's the king in finding these upload spots * He could be a human helping the robots Anyway, there is someone else that's putting up these save points for a reason. You could add that as another plot element for an introduction of a new character. [Answer] ### Villains are arrogant and looking for a diversion from conquering the world Villains don't build Dungeons so that nobody can get through to them. It might look like that and their minions might think that's the purpose of certain Dungeon designs, but in reality **it's just a test**. Once someone has made it through the Dungeon, fighting through hordes of minions and disarming deadly traps, they are worthy of being called a *Diversion* for your big villain. It's boring to be the master of all evil with nothing to do after all. From time to time you want to show off and display your powers. Making a Save Point at importants locations allows the wannabe *Hero* to not have to repeat the tedious little Dungeon they already passed. What use is it to have a tired Adventurer standing before you if you want to have an interesting fight? It's far better to allow the *Hero* to regenerate in the case you defeat him. The next time he might be able to fight a little bit better, a little bit longer and make things a little bit more interesting. **Once the *Hero* has proven to be worthy he is allowed to test his luck and abilities to entertain your villain. It's an honour. And giving the *Hero* the chance to try again might make things more interesting in the long run.** After all you can just destroy the little Save Point you purposefully left in your realm. It's your realm after all. It's not like those were placed there by mistake. Your minions might think they help you. Or that the Save Points might be a distraction for the enemy. Or something to make the enemy be less on guard as he thinks he just *saved*. But really, **it's all about making the life of your villain more interesting**. [Answer] **Save points are multipurpose energy sources; useful but also potentially dangerous.** Your save points need not be simply that. They could be high energy zones (natural or artificial) which can serve additional functions - perhaps the boss or other machines can charge up at that point, or use the focused energies there to augment their abilities while they are there. Maybe the save points are ancient defensive weapons which were hacked, their abundant energy being diverted for the save function. Bosses like to be near these places because of the additional functions they serve. But not too near - the energy zones are not always stable, and potentially dangerous. A long time spent in close proximity to these energies (perhaps spooky Z-point or [Casimir effect](https://en.wikipedia.org/wiki/Casimir_effect) energies?) can cause strange spacetime effects. Occasional energy surges can alter things nearby in bizarre ways. [](https://i.stack.imgur.com/CK8Dd.jpg) from <https://nele-diel.deviantart.com/art/Mountain-Obelisk-420037417> [Answer] One logical idea could be, that since *jamming* is preventing the restore point, **perhaps human "bosses" tend to want/need an unjammed area near themselves in order to have un-jammed communications**. That might make sense if the bosses are also commanders or need to receive communications signals. Another logical idea following the established *jamming* logic, could be that **there are just certain areas that aren't jammed due to reception details** ("*can you hear me now?*"), and clearing out the area around a boss is liable to give the robot forces time to locate one without being interrupted, whereas they usually couldn't do that before that point if there were still enemies around to disrupt them. Another logical idea would be that **taking over an enemy base allows destroying or modifying the enemy jamming equipment, and/or setting up one's own counter-jamming equipment or signal booster**, which is otherwise vulnerable unless/until the enemies are cleared out. As for another logic issue that comes to mind, about why the boss doesn't just run away after defeating one player, so the player gets to try over and over, perhaps these enemy bases are laid out such that the bosses tend to get cornered in a defensible strongpoint where only one robot at a time can approach, but also the boss can't leave without running into the rest of the robot army. In any case, I think it would also be more interesting and logical if there were a limit to retries and/or consequences for failing many times, such as a limited number of spare robots, and/or the human forces eventually mounting a rescue attempt for the boss, or the boss finding a way to escape, or other negative events happening while the player fails to defeat the boss over and over. At the very least, I'd hope the game would could defeats, so that a very good player gets some acknowledgement compared to one who fails many times. [Answer] ## Other rebels make serious effort to keep save points up! I can't take on this boss, I lack the ability. But what I *certainly can do* is keep a save-point alive here -- to make it a lot easier for those who can take the boss. You've made this easy, because you already have an in-game rationale for save points, and that rationale makes in-game characters very aware of the value of save points. [Answer] The re-download process is being monitored. The 'dungeon' and 'boss' were constructed specifically to attract people who want to fight to prove their mettle. When at least some inevitably die, their transmitted experiences are logged and analyzed to gather useful information. This includes things like fighting techniques, sure, but also things like reactions to bad-ass boss aesthetics for market research on how to sell hats. If your visceral reality feels suspiciously like a game, perhaps it's because you're not actually the one playing it. [Answer] **Saving isn't as easy as just being in a certain zone** So you're integrating into the narrative something that is often just part of the background mechanics of a game, and you want it to be plausible. So maybe it isn't just the case that you can't save from everywhere --maybe there are clear spots all over the place --but that you usually can't afford to take the time involved. Maybe it takes 10 seconds to upload, and if you move at all during that time, you have to start over. So you can only take the time to do that when you've cleared your area of lesser enemies, and are prepping yourself to take on a foe you believe to significantly stronger. If you are strategic about where the green and red zones are for upload, you can make sure that the only areas that "happen" to be both green and clear for a long enough span of time are the ones you want. [Answer] I would suggest a different tack on this problem entirely. Instead of attempting to justify building your fortresses such that they have a "Save Point", an area that allows the player to upload while still inside the building, instead offer the player a **backdoor** that they can open in the fortress to allow themselves to quickly and effortlessly escape, upload, and get right back into the building where they were. Now, instead of having to justify the boss leaving this upload security hole in a conspicuous, noticeable location, you can now tell a more convincing espionage story of a spy making future access easier for themselves and their future lives. Out of universe, most of the old Zelda dungeons are designed this way. While a player can technically save at any time, if they are killed inside the dungeon or turn the game off, they start over at the entrance. Progress through the dungeon is assured, however, by Link being able to create two-way shortcuts from various places in the dungeon back to its entrance. This also has the game design benefit of making it easier for the player to recover outside of the death scenario, since these backdoors now allow them to leave the fortress to resupply. [Answer] Simple. For the same reason the thing you are looking for is in the last place you look. Because you stop searching for it after you found it. Same thing here. YOU assume that save point in before boss fight. YOU decide who is a boss. Not your robot protagonist. For him the boss fight could be when he's facing last or largest human opposition. But he will only know that after many battles when he decide "Whew, that one I did 50 years ago was the worst. After that it was all piece of cake". Example. Dark Souls. New Game +++. Did the save point before the final boss in the New Game (so 3 playthrough earlier) was really before final boss? He wasn't final as you did fought after that. You adventure didn't end. Also such placing of SP is similar to placement of bus stops on the road. At the beginning, middle, and end. Because those are best pickup points from optimising of movement point of view. [Answer] ## Organic The quantum-powered hero gets headaches when perilous situations are coming up because he died in some other possibility and it collapses back through time to a point of low peril. Some possibilities collapse clearly; others don't. Naturally, boss fights are especially dangerous futures, so it's natural for collapses to happen right before such fights—it's a relatively—and for you to subsequently collapse back to this point. ## Unknown The small shrines to the ancient god of death aren't recognizable by most these days, and it might be the god has a shrine guardian preventing people from noticing. Regardless, you're in his employ, so you can pray at these shrines and the god of death will remember your prayer. Then you go assassinate someone as part of your beliefs. If you fail, well, the god of death isn't done with you; he'll reject your death and return you to the last shrine you prayed at. Perhaps a shrine is constructed there for your convenience since the god of death gave you this dangerous assignment and suspected you'd need it. It could also, be a natural feature the enemy camp incorporated into their layout. Maybe it serves as a common household decoration, and the unwitting decorators for your next target have helped you out. ## Immovable Due to the nature of the Ancient's engineering, there's no practical way to move the their restoration chambers. If only someone had the right genes to make use of them... If no one is known to be able to exploit these inconvenient chambers, then enemies will just build around them. If this spot is the best for the enemy boss, then the "unusable" restoration chamber outside the door doesn't make a difference—it's alien tech that they had to work around. Note: This one doesn't work in the long-run. Anybody finding out that an enemy can just respawn indefinitely in their base will relocate somewhere safer. ## Secret Some of your robotic compatriots have discretely embedded some reconstruction points in the enemy base. It's doubtful the humans will figure out about the reconstruction points: all robots look the same, so how could they know it's the same robot attacking again and again. Even if they were looking, it'd be hard to find them without a special robotic vision mode/mod. Your compatriots would naturally plant these points in optimal spots for you, and right before the Big Bad Boss is, I would think, very optimal. Note: This one doesn't work well in the long-run unless the antagonists are really dumb and don't pick up on the pattern, but it would probably work longer than the immovable solution. [Answer] **Geographic/Geometric** Jamming can be overcome by directed transmissions (shaped beam radio frequency or laser) with direct line of sight (LOS) to orbiting satellite constellation. Levels appear to involve infiltrating a building, finding a bad guy, then fighting him. Saves are available when you are outside (beginning save point), and at any time that you can re-acquire direct LOS with one of the satellites (middle and pre boss save points). Not every piece of the sky will always have a peek at a satellite, so the lack of a save point near some windows, roofs, docking bays, etc should not be too jarring. The same methodology can be used to explain the sparse save points on an outdoor level depending on the terrain, LOS to ground based repeater stations, and robustness of your satellite constellation. [Answer] **Secured physical connection** In the scenario of wireless signals being unusable because of jamming, perhaps there are physical access points they can use. They're normally secured and could possibly even be dangerous to access under normal circumstances. However, there are a few that are left unsecured by a sympathizer on the inside of the human military. Knowing where the dangerous foes are in a base, the sympathizer strategically disables security on these physical access points near these dangerous foes. These access points give the robots secure access to their networks for uploading a snapshot to the rebel network. As a bonus, you get an extra character to make the story a little more interesting if you choose to involve the sympathizer in the story. [Answer] There's almost no games that even bother to do so, nor do I ever want all games to even attempt it as the narrative will always end up samey, silly, and contrived trying to shoe horn it in and instead leave it up to the player to acknowledge it as an acceptable break with in-game reality for sake of player quality of life. let the rare game who can plan their story around it to be a unique gem, and let the rest not have their narratives twisted to try and explain things that require no in-universe explanation. And if you can't convincingly make it work without breaking immersion...DON'T. Just make sure that your game's difficulty and focus is properly balanced around it. IMO if the battle NEEDS a check point right outside of the fight and the game isn't for all audiences including small children, then the difficulty should justify such leniency. They exist PURELY as a quality of life gameplay tool based on feed back from players who played games in the older generations of RPGs where save points either didn't exist at all (Dragon Quest style return and talk to the King/A Priest to save, which remains a staple in that series in the majority of games outside of some of the handheld ones being a little more forgiving due to the nature of the handhelds and the stop-go style of play) or only allowed you to save on the world map with save points tending to instead be found in VERY long dungeons at around the half-way point due to length rather than any specific challenge point. You could work around it, but most games BARELY justify the save system at all, if they even bother. A lot of save systems aren't even attempted to give them a justification. [Answer] The robots makes a save point by uploading their memory to mission control. These pre-boss save points are the command centres of the militarized city/fortress/flying ship/headquarter. The boss' room is always close to the command centre because they need to be in the command centre to command their army. In most part of the enemy base, there is a wireless jammer so wireless communication does not work except on a few designated points designed with wired connection to the outside world for use by defenders, but it is standard operating procedure by the defending army to disable these access points when an area is overwhelmed by attackers, and this can be done remotely by the command centre. The command centre are always designed with unjammed communication with the outside world so that it can communicate with other bases even while the wireless jammer is active, so they have been designed with a physical wiring that aren't affected by the regular jamming system and cannot be intercepted by the heroes without crushing through layers of thick concretes. These command centres are built on the assumption that once the opponent reach this point, the base must have been lost, so once you reach the command centre there's little preventing you from hijacking the data link to upload your memory. Knowing that the robot attacker have been using these data link to upload snapshots, newer bases have been designed with data link self destruction system, so if the defender senses that they are going to lose the command centre, they would trigger this self destruct mechanism before leaving the command centre, so now attackers have to figure out ways to stealthily gain control of the command centre without the defender having chance to trigger self-destruct. When given intel about the building infrastructure, the attacker can pop up extra save points by using explosives, and heavy equipments, on vulnerable points, to get access points to these physical wires outside central command, but blueprints for enemy bases are highly classified information, so they're not readily available in most missions and blindly blasting things without such blueprint would just be a waste of your limited supply of these powerful explosives/equipments. The switch to disable the jammer is also often located on the command centre. So once you conquered the command centre, you also gain control of the jammers and can therefore enable saving anywhere using wireless datalink. ]

[Question] [ Most species of animal, especially mammals, have a special skin cell the produces melanin, which is responsible for the color of their skin, but orcs are generally depicted as green creatures and, of course they are another race too, but for this question, assume they are mammals and are green. What will be the evolutionary trait that causes it and is there any real benefit should they form civilization resembling our modern society? [Answer] Flamingos are originally born grey but become pink due to eating brine shrimp, which have a natural dye called Canthaxanthin from their diet brine shrimp and blue-green algae. If an orc was like a flamingo (lol) then they could become green by eating certain plants/animals that have natural green dyes or colours that make green such as blue and yellow. And don't worry that a flamingo is a bird, it happens in humans as well. An example is the Paul Karason, who [turned blue](https://en.wikipedia.org/wiki/Argyria) from drinking colloidal silver to treat his dermatitis, and the blue skin from excessive colloidal silver ingestion is permanent. Another is eating carrots or pumpkin in excessive amounts turning your skin yellow. So just make your orcs eat something green a lot to make them green! [Answer] There are two green mammals, actually. And both are sloths. The [two toed and three-toed sloth](https://www.theguardian.com/notesandqueries/query/0,5753,-1357,00.html). In this case, it's a type of algae, which is only present on sloth hair and is a symbiotic relationship. But you aren't talking fur, you're talking skin. Still. You can use this as a model and you'll want to look at bacteria and fungus present on all our skins. Humans can get a condition called [Tinea Versicolor](http://www.mayoclinic.org/diseases-conditions/tinea-versicolor/basics/definition/con-20024674) that causes discoloration and spots. Basically it is a fungal overgrowth. You can take this concept and run with it. Here's how I would do it. There are different breeds of fungus or bacteria present in orcish populations. The conditions of their skin is a perfect home for them and may give some benefit to orcs. They might be born a greyish color (of which there are plenty of examples in the animal kingdom) but as they pick up the fungus in their tribe, they gain coloration. Depending on the particular fungus their skin can turn blue or green as they age, and they may even get freckles of an alternate color or from colonies that are more intense. Their starting color, which would range from a very light grey to almost black will also determine what kind of bacteria or fungus can live there. They may also bathe in material that encourages the growth, and may have "tan lines" because it could react differently to sun. The advantage is up to you. You can look to the sloths, it can help with sun screening their delicate hides, or even help to heal and toughen upper layers of the skin. If it is fungal, certain jobs and contact with certain things may kill the fungus--that will be up to you as to what. You might even have their toenails be a brighter or different shade. In humans a blue or green toenail would mean disease, but for them, it means that they are healthy. There could be various diseases/medical conditions that mean a loss of pigment, or an overgrowth. An overgrowth could be temporarily advantageous, toughening their skin, making them nearly unstoppable in battle, but shortening their lives. Just using reality as a jumping off point into the fantastic! The science can be partially based in reality, but since you are talking about a species we don't have on this planet, you can really do whatever you like, as long as it makes sense and is internally consistent. The orcs themselves aren't likely to know what the mechanism is. If one orc joins another tribe, they might slowly change in color, if that fungus is dominant and can kill the original, after a lot of contact with the other tribe (especially intimately). For example, dark green can be a stronger fungus than the light blue. So a dark green orc might never turn blue when they join the a light blue tribe, but after years they might gain a more teal tone (especially if they marry a blue). But a blue might quickly become green. They could all be green, I'm just spitballin' here. Once a colony is established on their skin, it might not ever change--that's up to you. Such a system could lead to prejudices of course and could be interesting socially. [Answer] I liked Fleon\_'s note about diet. Let's add some more... * Perhaps their skins are occupied by symbiotic algae which synthesize some vital nutrient for the orc. The green is just a side-effect. * Could be that the orcs evolved in an area of dense underbrush, and the camouflage was useful. * Might be the opposite ... they evolved in a very non-green environment, and the green is a sexual display (a la peacocks), advertising that the orc in question is *so very tough* that he doesn't *need* any stinkin' camouflage. * Heck, I'll just toss this one in. It is a well-known fact that orcs begin their lives as photosynthetic pollywogs living in ponds and puddles. The retained the green coloring because it's coded by the same allele as a very valuable trait (e.g. tendency toward mindless, cartoon-like violence). The green has little effect in their adult lives, though I'll say they **do** enjoy them some sunbathing! Update: * How could I forget polar bears? They have hollow fur for buoyancy, and occasionally the fur gets colonized by algae. Here's a nice discussion of same: <https://www.quora.com/Why-does-a-polar-bears-fur-turn-green> . Do orcs have fur? [Answer] In world of warcraft, orcs are born with grey skin, but it turns green when they are exposed to fel (demonic) magic. Trolls are green because they have symbiotic algae that photosynthesis and give them better stamina than one would expect. [Answer] A simple evolutionary reason would be camouflage. Just like many animal's fur is colored in a way that hinders detection, the skin's color can evolutionary adapt to improve camouflage as well. Preconditions for this is an environment rich in green's, and a sufficient time span between orc's ancestor's losing their fur and the present. [Answer] **The only reason green pigment is rare in mammals is most mammals can't see green**, so mammals lost the "green" pigments pretty early. It all started because existing pigments could not make hair green, the blue pigments (tybalt blue) used in skin and feathers don't work in hair,(most animals make green by combining blue and yellow) so if mammals had wanted to be green they would have had to evolve a new pigment, without color vision there is little reason for this to happen. Note this is why green still occur in eyes. The existence of better color vision in primates has led to a greater diversity of coloration they have blue skinned primates, but they still can't get blue or green hair. It is entirely possible they may evolve a new green pigment (that is how they got better color vision than other mammals after all), it could even be a mutation of an existing pigment. Maybe they don't make red or yellow pigments anymore instead making new pure green pigment. As for why this mutation would spread you have three options, although you could combine these as much as you like. 1. Camouflage, maybe they live in a jungle or somewhere else green blends. 2. Sexual selection, maybe it is novel enough that mates find it attractive instead of repulsive, considering all the other weird things that sexual selection has produced this one is easy. 3. maybe the new pigment is actually better at protecting the underlying tissue than the previous pigment. maybe it reflects the ultraviolet end of the spectrum better which is what makes it green. The effect on their culture will be minimal. Although if you include #2 they may find non-green skinned people look sickly or ugly. [Answer] I really like the Warhammer 40K answer: The [Orks](http://warhammer40k.wikia.com/wiki/Orks) aren't really green-skinned but they have plant-like organelles that undertake photosynthesis which turn them green. These feed their Ork host excess carbohydrates in exchange for a place to live and easier access to nutrients. The extra energy makes Orks better warriors, stronger, faster, and with greater endurance *and* increases their rate of healing letting them shrug off wounds that should be lethal in just a few weeks. [Answer] Less of a biological than a social factor, but perhaps Orcs get tattooed with green ink - and get more tattoos the more successful they are as warriors. Similar kind of idea to ancient Picts painting themselves blue before battle with woad dye (see here for more info: <http://www.woad-inc.co.uk/history.html>). The only reason we see green Orcs is because we only ever encounter them in battle, and never in any domestic environment - their natural skin colour could be bright pink, for all we see of their non-warrior citizens. [Answer] Since orcs tend to live in damp, dark environments which would support all sorts of bacteria/fungi you could argue they evolved copper stores in their epidermis as an [antimicrobial](https://en.wikipedia.org/wiki/Antimicrobial_properties_of_copper) [Answer] They have a sort of [Green Jaundice](http://www.amjmed.com/article/S0002-9343(10)00389-X/abstract) because their liver is rotten. That is also a good explanation for their ill temper, because as [another article](http://www.sciencedirect.com/science/article/pii/S0002934309003398) states: > > "It's not easy being green!" > > > ]

[Question] [ When we look at the future with our sci-fi glasses on, most new weapons are electrically powered, such as coil guns, railguns, laserguns. But what about vehicles? In 2014, [Tesla released all patents](https://www.tesla.com/blog/all-our-patent-are-belong-you) making them available to everyone; so why not take that in to military use? [The M1 Abrams tank](https://en.wikipedia.org/wiki/M1_Abrams) has a 1,120 kW motor and in comparison the [Tesla Model S](https://en.wikipedia.org/wiki/Tesla_Model_S) has a 568 kW motor, so it wouldn't be unrealistic to up-scale the motors and batteries. The Tesla has an effective range of 265 miles (426 km) and the Abrams tank has an effective range of 265 miles (426 km), so there isn't much difference there either. What would be the main reason **not** to convert armored tanks into electric, zero-emission vehicles? What challenges would the R/D Facility have to overcome? Assume the R/D department will use the patent to develop their own product rather than retrofit existing Tesla hardware, thus making motors and batteries more "war"-friendly. **Petition:** We already got a lot of good answers regarding the lack of good batteries, I think we can stop beating the dead horse, and move the debate from the question "Are there any good batteries?" to "What challenges do you need to solve to make a next-gen-tank?" [Answer] # Time It takes few minutes to load fuel into a tank. [150 US gallons (570 L) per minute](https://en.wikipedia.org/wiki/Fast_fuel_system) is possible. So 3–4 minutes from empty to full for an M1 Abrams (not sure if that's the system installed in it, but it's just a glimpse on possibilities). On the other hand, it takes [15–30 minutes to charge Tesla](https://en.wikipedia.org/wiki/Tesla_Model_S#Supercharger). Doubling it for double power, and you have it: **4 minutes wins with an hour** when it comes to be up and running again. # Reliability Diesel engines are old, well tested, reliable and sturdy. To some extent, you can still ride if one of the cylinders fails. You can still ride if your fuel is leaking a bit. Lost one cable in accumulator battery? One coil in electrical motor, and you're toast. Gas turbines are also old and true. Not as old and reliable as diesel, maybe, but older and more tested than electric ones. Tesla engines are built to be replaced, not repaired in common shop. Personally, I would prefer to take more rounds and more fuel, and engine that can be repaired, than to have to load spare motor. Note: I'm talking about modern Tesla motors, not good old heavy, bulky, energy inefficient but sturdy and easy to maintain submarine electric motors. And I'm talking about modern energy dense batteries, not old, heavy lead-acid batteries. Old electric tech was just too heavy and bulky for land vehicles, but indeed it was reliable all right. # Personnel Think how many guys with years of experience with gas engines you have in army. A lot. And many have experience longer than Tesla cars even exists. You can't replace that by some classes. When it comes to battlefield, you want equipment your people will be able to use, maintain and fix. Don't forget that [railguns are simple](https://en.wikipedia.org/wiki/Railgun#/media/File:3MpUJGm.jpg). Knowing how to use one and even how to make simple fixes is by far not enough to also know how to fix a coil in electric engines or re-wire battery pack to go around a broken unit. Especially when fixing gun can wait, and fixing engine cannot and you have to do it, even if the bullets are flying. # Logistics Electric lines are natural target. You can move fuel quite easily. Not so with electricity. You can't just load electricity on a truck and move it where it's needed. For many diesel engines, you can use things like frying oil, moonshine, etc. to make them run. It's not good for the engine, but who cares if this allows you to save your life or to go to position and defend a city full of civilians? # Storage You can store fuel a long time without losses. Accumulators, on the other hand, discharge when not used, slowly but significantly. You do not want to be surprised by empty battery. # Ease of checking You can just knock on the fuel tank to hear if it's full, empty or in between. You need device to test if battery is full or empty. Surprises are bad. Knowledge is life. Of course you can have a chip to monitor cells. Worked great for Samsung Galaxy Note 7, right? **[Well, nope](http://www.androidcentral.com/samsung-galaxy-note-7-recall)**. At least empty fuel tank will not explode in your face. # Safety As [fr13d points out](https://worldbuilding.stackexchange.com/questions/57477/zero-emission-warfare/57480?noredirect=1#comment162969_57480), lithium-ion batteries [tend to explode violently](http://www.techlicious.com/blog/the-risk-of-exploding-lithium-ion-batteries/). Fuel tanks do not—still not exactly safe, but diesel can't be ignited by simple puncture, and requires air to burn. Same for natural gas, gasoline, jet fuel and other burnable fuels. Batteries burn well on their own. [Answer] # Availability and portability of energy When you are fighting a war, emissions and the environment is not really on your mind. What you care most about is that your weapons work **when you need them**. Now granted electricity is very portable and available, **when you have a working infrastructure**, which makes **peace-time** use of electricity to power vehicles a splendid idea. In war however, you can expect that electricity will most likely not be available, even in urban environments. And when it comes to having electricity available out in non-urban environments, well then you are expecting a bit much. Fossil fuels come in handy in war because those you can move about in tanker trucks. And even if one or a few of your trucks take a hit, those are easy to replace, plus they are mobile and not all that easy to hunt down. The power grid on the other hand is static and immobile. So blowing up a power switching station is very easy, and whoever was depending on it is pretty much screwed for several days, if not weeks or months. Fossil fuels have stuck around because they are available, portable and work well enough when we need them. [Answer] **Currently humanity has no means to *efficiently* store electrical power in big volumes** **Batteries** is the first and largest problem to solve, before making tanks fully electrically-powered. Tesla uses lithium-ion batteries: * They are costly to produce * They lose capacity naturally, even without being in use. * They lose stored power, even without being in use. (Those two make them pretty unfitting for war use - 2 years old tank will need a full battery change before going to combat, unless you want it to be only 30% effective). * Their effectiveness depends on environment conditions (reccomended use/store temperature is ~25C). * They shouldn't be discharged fully (meaning you will have to bring some "useless" weight with you). There are even more "cons", which can be discovered by surfing internet/wikipedia. P.S.: **This problem can be avoided on larger vehicles by removing the battery completely**: * [nuclear navy](https://en.wikipedia.org/wiki/Nuclear_navy) * [nuclear ships](https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Civilian_nuclear_ships) However, making a huge tank or a "walking citadel" with nuclear engine seems to be too dangerous/costly. Sci-fi writers use the idea of "portable nuclear reactor" to make such things happen. [Answer] Expanding on my comment: Electric engines and electric systems in general have many advantages (an electric engine potentially needs no transmission, for example), but overall, the real killer is that battery technology is nowhere near as energy dense as hydrocarbon fuels. Other issues like the length of time to charge batteries (a commenter named GoatGuy on NextBigFuture has rebutted this on numerous threads, providing detailed calculations involving energy, voltage, heat etc. Sadly, since these are comments and not the articles it is hard to look up), battery weight and shelf life all factor into this. Even environmental factors like outside temperature affect battery performance (ever try to start a car in the dead of winter, when the temperature is well below zero?). Now we can go partway there, by combining the energy density of hydrocarbon fuels and electrical energy. The chemical energy of the fuel needs to be extracted by fuel cells, rather than burning them in an engine them tapping the engine power through a generator. Fuel cells are very efficient on their own (estimated maximum efficiency is @ 60%, depending on the type), and direct conversion to electrical energy eliminates multiple "step possess losses" of going through different systems. For military vehicles using hydrocarbon fuels like JP-8 (the NATO standard diesel and helicopter fuel), you would want a Solid Oxide Fuel Cell (SOFC). These fuel cells run at elevated temperatures which "crack" the fuel into hydrogen and carbon monoxide, both of which can be oxidized across the membrane and converted into electrical energy: [](https://i.stack.imgur.com/Lfh8P.png) Most SOFC's today are built to run on natural gas, but there have been demonstrators using diesel fuel, and there is no conceptual reason not to have a diesel powered SOFC. If you notice the diagram there is also a lot of heat energy being released, and a bottoming cycle like a turbogenerator or even a small steam generator could be added to the loop to harvest some of that energy. The turbogenerator would resemble a turbocharger, with the turbine in the hot exhaust stream spinning a generator, and BMW has experimented with micro steam turbines which use engine exhaust heat, so the concepts have been tested in the real world. The primary disadvantages of an SOFC is it needs to be brought up to operating temperature to work (@ 800 C), so no "instant on"; and current versions are made of brittle ceramic materials (mostly because research is on stationary power generation applications). An insulated container will assist in the former problem (once it is running, the reaction is exothermic, so the SOFC remains hot), and material science can be used to find better materials for the fuel cell stack. Vehicle powered this way will have the range and logistical advantages of a diesel powered counterpart, but are potentially lighter and have a great deal of electrical power to run the engines, sensors and even laser or railgun weapons. [Answer] There is a difference between car and tank. The Tesla Model S rarely utilises more than 5% of that 568 kW motor. The tank, on the other hand, has to move its 60+ tons on unpaved terrain. To provide the same effective range up-scaled Tesla battery pack is going to be at least 10 ton. Maybe 20. 10-20 ton of fragile, flammable potential disaster. Add to that up-scaled recharge time (many hours at best). The end result is of no interest to the military... [Answer] Handling large amounts of electrical power is non-trivial. Pushing large amounts of power into batteries is decidedly non-trivial. Any battery-powered electrical vehicle will need to recharge the batteries on a regular basis, just like a diesel-powered vehicle needs to refuel on a regular basis. The difference here is that diesel is just a liquid that can, absent some relatively trivial engineering problems, be poured at huge (almost arbitrary) rates. You can't readily do that with batteries. [Cem Kalyoncu mentioned solar panels](https://worldbuilding.stackexchange.com/a/57491/29) (and in fact, this answer started out as a comment to that answer), which is a decent way to get power in an off-grid scenario. The odds that electrical networks continue working perfectly in a war scenario seem low, to put it mildly. Not only that, but to get any reasonable recharging time, you'd be drawing on the order of *megawatts*. That's a small power plant. Let's say you build the tank around an 1,100 kW (1.1 MW) engine. Insolation is 1 kW/m$^2$ or less in most parts of the world, and you might get 8-10 hours per day of good insolation at best. Solar panels generally achieve something like a 30% conversion efficiency, up from early ones which were more like 10% efficient. Say you have 400 m$^2$ (20x20 meters) of solar panels. That gets you somewhere on the order of 120 kW of electrical power. Consequently, to a first order approximation, with good assumptions about what time of day it is needed, to match the energy requirements for *driving* the tank around, you would need somewhere on the order of 4,000 m$^2$ of solar panels. The more reasonable 400 m$^2$ will give you one hour of driving time per *day* of charging. Add to this that many military operations are performed during nighttime to help conceal the activities against the enemy. A large pack of solar cells might be enough to recharge the tank's batteries sufficiently to move it from one place to another, but it won't be enough for actually having the tank perform useful (in a military, combat sense) work. For this reason, an electrically-powered battle tank would be completely dependent on huge amounts of infrastructure. **Transporting diesel by tanker vehicle is far, far easier.** [Answer] I have read many good answers for this question. Let me explain some points that may also come into consideration: **Redox Flow Batteries** A comparatively new approach to batteries and recharging, where you'd use a liquid electrolyte storing the power, which can be quickly replaced with fresh ones. This way you''d get rid of the land lines for recharging. They are also quite cheap. **Liquid Anode Batteries** Molten Salt Batteries. Uh, those... they have a relatively high energy density, but are filled with stuff you don't want to have inside of your tank. If one of those ruptures, you're toast. They are pretty cheap though... **Fuel Cells** Well, this one is old. Really old. The technology was already available during world war 2, although not quite exploited to the point it could have been. Can be refilled with oxidant and fuel in a similar way to combustion engines. **Energy Density/Specific Energy Considerations** Other answers have pointed out the logistic problems batteries. I would add that there is a general problem with the energy density and Specific Energy of batteries when compared to fossile fuels. Most batteries don't even come close to the amount of energy that is stored in a Liter of Diesel or jet fuel, let alone the part of it that is actually usable. I would think that this is the problem generlaly with electrical vehicles that don't have an auxilary power supply. While hybrid machines could be used, like back when they tried them on the King Tiger, using combustion generators to produce the elctricity, such combined systems seemed to be far too complicated for a military application. **TL:DR** The main problem is energy density and logistics. The logistics side could be solved if those Redox Flow Batteries work. Secondly, energy density. I don't know how large the energy content of the liquid electrolytes are, but they'd have to match the 46-48 MJ/kg (specific energy) / 26-40 MJ/L (density). Li-Po batteries have around 1 MJ/kg and 3 MJ/L. Thats not nearly enough... [Answer] If your aim is to kill people and destroy stuff, emission control becomes irrelevant. [](https://i.stack.imgur.com/CpKAH.jpg) Bombing Bagdad – and later rebuilding it! – caused more air pollution and excess heat than all the air planes and tanks in that operation. If you want clean air, you do not make war. An emission-free tank is like putting vitamins in cigarettes. The little good that does stands in no relation to the harm of smoking, and the only way to make cigarettes healthy is to not smoke them. [Answer] Full electric system might have advantages, aside from the glaring problems. So this is on top of other, rather grim, answers. * A full electric system will probably use multiple electric motors. This will serve as redundancy and will allow tank to go on even if one is blown. * A full electric system can have disjoint batteries leading to motors. If one block develops a fault, rest will go on. * If necessary, every tank can be equipped with foldable solar panels, thus if you fail to find electricity you may continue next day. * Not within zero emission spec but you could have portable diesel engines to generate power if it comes to that. * In hostile lands, mobile thermonuclear power station can have double use: as a scare tactic and power station. At home, you can have power stations seeded. If zero emission warfare is considered, probably countryside would be littered with renewable energy generators. * Electric systems have less mechanical peripherals and easier to do repairs. That said, it is not very good idea with the current technology. Better batteries and widely used renewable energy is necessary to take advantage of this technology. [Answer] Its about energy density. A vehicle needs to carry enough energy (stored in batteries or fuel to move it) A Tessla can afford to have most of its mass (less than 2 tons) dedicated to storing energy. But a tanks has lots of mass that has to be dedicated to armor and weapons. [according to Wikipedia](https://en.wikipedia.org/wiki/Energy_density) Lithium ion Batteries have a energy density of 0.5 - 8.75 MJ / KG and the less expensive lead acid batteries are .17 MJ/KG Where fuel has a density of 46.4 MJ / KG Which means if you switch to using batteries to store your power you need 53 - 272 times as much weight dedicated to energy storage. It is true that electric motors are more efficient but the ratio is closer to a factor of 2 -4. Even with higher engine efficacy you need to spend 50 times as much weight on fuel which is huge think a 60 ton tank suddenly going from 2 tons of fuel to 100 tons of batteries. The extra 100 tons of weight increase the energy requirements to move the tank which require still more batteries and a stronger engine which in turn weighs more and so on. [Answer] One thing that's not been considered here is that a large main battle tank might become just as irrelevant on the future battlefield as a cavalry charge\* in 1939. When its possible for the adversary to employ huge swarms of drones both in the air and land a tank might just be a slow lulling deathtrap. Creating armour capable of stopping a rail gun projectile moving at 2km/s is also much bigger technological hurdle than scaling up an electrical motor and battery technology. We already have electrical powered unmanned flying aircraft and ground vehicles that have been used in combat. [Answer] Since electric motors produce much more torque than internal combustion ones for the same size occupy less space, have less weight, easier to maintain, less complicated + lost of other advantages, tanks will surely be 0 emission in the future. It's just a question of when a fast rechargeable battery will be produced. Electricity is available anywhere you have a socket. Diesel or gasoline you can only find at pump stations/your own army supply. Otherwise, "All is fair in war and love", so 0 emissions will never be a priority for the army, it will only be a question of electric tanks being straight upgrades compared to internal combustion ones. P.S. Tesla P100D is the quickest production car in the world, 0-62 in 2,5 seconds, so electric cars have already beaten the internal combustion ones in terms of power, space, weight, maintenance etc. The only problem is the slow charging/poor energy density batteries. [Answer] **Availability of fuel** Tank motors are not normal diesel engines, but multifuel engines; modified diesels or gas turbines which can use nearly anything combustible (oil, ethanol, gas, diesel, petroleum) and even in bad quality. This allows tanks to use already existing infrastructure for refuelling and makes logistics much easier if you do not depend on a single fuel with good quality. This also raises the question: *How exactly electric energy should be transported for refuelling tanks ?* sdrawkcabdear's answer put out nicely how **shoddingly bad** lithium batteries are in comparison of energy density against fuels (Unfortunately people are still unaware how bad it is because the Tesla hype). High voltage transmission lines are easily disrupted (even without the intention of pulling them out) and you need a non-movable distribution substation to convert them into anything usable and they can be easily destroyed or sabotaged. The only thing already mentioned in the other answer are fuel cells; if they finally made a breakthrough invention like LEDs which allows us to convert fuel reliably, they will in fact replace emission engines. Their advantage is that they do not need gears, an electrical engine is much more simple and robust and they are much, much harder to detect (Emission engines have strong infrared signatures, emit carbon dioxide and are loud; tank engines are even detectable after a cooling period of hours). Electrical engines and fuel cells have also a much better efficiency, comparably something in the 70% range while emission engines have only 30%. So if your sci-fi story has this breakthrough, electric tank are very persuasive. [Answer] Actually the army does care about the environment. Yes, they are "green". But even more, **tactically, emissions give you away!** **Visible smoke** has been a huge deal for centuries. The navy able to distribute clean-burning coal to its outposts got to sneak up on the other guys. Engines are dreadfully inefficient. The waste heat makes a huge **heat signature** for weapons to lock on. The futurists talk about swarmed weapons, but for decades there have been [cluster bombs](http://abcnews.go.com/Technology/story?id=97677&page=1) which will make short work of a tank division because each bomblet seeks out a tank's engine compartment. They only work on tanks with engines. They can't tell an electric tank from a pile of pipe (or a decoy tank). Identifying tanks visually (especially from decoys) is a much harder problem. Engines and turbines make a lot of **noise**. Whereas an electric drive is spooky quiet! That would allow them to "sneak" in ways currently infeasible. So yes, an electric tank is definitely a potential winner. Just beware the blunder of comparing an automobile's peak horsepower with an industrial engine's continuous horsepower. **Recharge** is easier than it sounds. You just need a small diesel APU (or hey, three of them for resiliency) such as the units made by Thermo King. This engine will be efficient and durable since it is optimized for one continuous load. A small fuel tank could be kept onboard, with larger fuel tanks mounted outside or in a trailer. The trailer could be dropped in combat. *I'm not even sure I would bother with plug-in recharging, since that would motivate the enemy to destroy electricity infrastructure, which would hurt civilians.* **Solar panels** which unfold and cover the tank would be awesome. The extra battery charging; masking heat emissions from APUs; and making decoys *very* effective. (the decoy could be a plain truck with the exact same solar array, charging itself and the tank too.) Tanks are not that fast, and they spend a lot of time idling while the combat engineers clear obstacles. A 200-mile tank charge would be one long, slow, miserable day. Armies have long had a problem with the tanks outrunning the support infrastructure. Several times in the North Africa campaign, tanks had to suspend a very successful advance, or allow the enemy to escape, because the fuel bowsers couldn't keep up. The efficiency of an electric drive would really help. [Answer] **Forget Batteries** If the world has got to the stage where armored warfare is conducted using electrically powered vehicles, I'm assuming someone cracked the wireless power issue. That's right, no more having to refuel! Buy the newest M1E Abrams MBT with satellite power link! The technology has already been demonstrated, powering a light bulb through, afair, 1ft lead. Combine it with solar collector satellites, LFTR reactors or what ever other energy source you can come up with and you've got a battle force that just keeps running. This is actually something in development, and something I keep getting excited for, only, it's taking a while to become a commercial possibility. [Answer] One of the primary objectives in designing military hardware is ruggedness. You don't want to your military hardware to break easily, compare military grade radios with your smartphone. Apart from tolerating harsh physical conditions, military hardware also needs to deal with a huge range on operating conditions. If your smartphone is designed to be paired with a 5 V battery, it might not tolerate a 9 V one. Tanks often use [multifuel engines](https://en.wikipedia.org/wiki/Multifuel), which can run ony virtually anything. This really comes in handy if you manage to come across fuel sources, be it a civilian gas station, an enemy jet fuel dump or some trucks transporting diesel fuel. Whatever you find, fill up and carry on. With battery based tanks you impede you armored forces, unless the economy as a whole has moved away from oil-based fuel (for trains, ships, airfraft, ...). In a post-oil society, there might still be fuel around that is chemically stored energy, e.g. compressed hydrogen gas or other forms of hydrogen storage for use in fuels cells. So even in a post-oil scenario batteries might not be your first choice. --- I also would split your question into two parts, or two questions, since the issue of electric mobility is independent of electric weaponry. If global oil production stops, you might need a different source of energy to move your Abrams around, but why replace chemical explosives? There might be reasons, but mobility and weaponry are independent from each other. A Tesla with a gun, or rocket launcher is still a zero-emission vehicle. As others pointed out, waging war is never zero-emission. Thus, I wouldn't bother to make the weaponry zero-emission. If you set a chemical plant on fire with a laser weapon or conventional bombs, the total amount of pollution dwarfs the pollution from the weapons themselves. [Answer] ## What will warfare look like if we *can't* use petroleum/fossil fuels to power our (military) vehicles? I'll rephrase the question such, to narrow down the answer, hopefully keeping to the intent of your question. It leads to a question of why, which I won't address here. It will depend greatly on the timeframe of the transition. When, but more importantly how long. The shorter the transition time, the less radical the changes will be. In the shortest timeframes, you have to use the engines already in place, so one will simply have to use/invent fuels that can be used in place of diesel/gas in the same engines. I believe we have ways to do this already, but it is not economically viable to do so compared to pumping oil. Already at this point we could achieve carbon-neutral. In longer timeframes, we can start to replace engines. This opens for other forms of liquid fuel like ethanol, but most logistical systems (transport and delivery in particular) will be unaffected. If we have at least several decades, lots of money to spend on this "modernization", and the prerequisite technologies exist already, we can start moving the bulk of active deployed forces onto other paradigms. The consensus of the answers here is the techs do not exist in the case of electric, and that there are several pieces currently missing. Between that research and several decades to deploy, we're unlikely to see a wholly electric military in our lifetimes, if ever. [Answer] There's another factor that didn't get mentioned: Fuel is a lot more available than electricity in a war environment. You very well might capture fuel stocks (and the M1 can run on quite a variety of different fuels) but capturing an operating source of electric power is rare. [Answer] Depends where you're fighting. The original tank concept was designed during world war one as a way to counteract trenches. The *modern* tank to a large extent was designed around conventional warfare of the sort that was projected towards the end of the cold war. That said, most modern wars seem to be fought in urban or *post urban* areas. Rather than an *electric* Abrams, a different sort of armoured vehicle might make sense. Lets start with the *issues* of a electrical tank - You would have limited range, need to spend time recharging it (and that electricity needs fuel anyway) and the energy density of batteries is a bit naff. The tesla S has a range of say 500km. *Assuming* the same range, you're basically limited to staging areas roughly 250km or less. Modern Lithium Batteries are also *gloriously* inflammable. Its actually pretty hard to set diesel or even petrol alight. Tanks are also much bigger vehicles, with a less efficient drive system (even if treads have their own advantages), That said, we have modern fighting vehicles that run off electricity anyway - submarines. And many of them use a *combination* of fossil fuels and batteries. A *hybrid* tank might have the option of using batteries, topping them off with *periodically* run, smaller engines, and use electrical motors for a simplified drive train. That said, the modern MBT isn't really the best sort of vehicle for urban combat. They might make good command vehicles but many modern armed forces are moving off it. Now a swarm of technical type vehicles, completely noiseless until they start firing... that would be scary. [Answer] **PHYSICS** Horsepower doesn't matter, torque matters; the AGT 1500 engine that runs the Abrams will produce 1500 horsepower, so will an electric motor; But the 3000+ ft lbs of torque to propel a 70 ton vehicle. To do that with an electric vehicle the motor isn't the problem, the stress on the motor is, would require a cooling system about a 1/3 the size of the tank. A battery and the voltage cables needed to propel the vehicle? that's the challenge. The vehicle would need a BIGGGG battery. An M1 Abrams carries 500 gallons of fuel (65 gigajoules of chemical energy) An Abrams Tank would need over 150 Tesla batteries to carry 65 gigajoules. Then each battery pack weighs 1200 pounds. 150, 1200 lb packs would increase the vehicles weight by 90 tons. So you're looking at 150 ton vehicle. So that's why we don't have electric tanks. Electric powered infantry carriers maybe, but a tank? [](https://i.stack.imgur.com/T955s.png) ]

[Question] [ In my setting we have two [Kardashev type III](https://en.wikipedia.org/wiki/Kardashev_scale) civilizations who have been at war a long time and their war has now shifted into our neighborhood. These civilizations are until now unaware of human existence (Humans are type II by now). Humans, however, are by lucky chance aware of the war. **In these circumstances what would be the steps taken by humans to safeguard themselves from the ill effects the war may have on them?** I have read this [question](https://worldbuilding.stackexchange.com/questions/25748/what-would-we-see-of-a-devastating-interstellar-war-between-alien-civilizations) but the answers don't really cover it. I would like a diplomatic and political approach which safeguards humans from the possible ill effects of the war [Answer] The best the K2 civilization can do is to attempt to shield themselves from collateral damage caused by whatever the aliens are using. This is problematic since they could be using principles and physics which have not even been discovered yet by the KII civilization. In that regard, the question is somewhat like asking what effective steps Knights could take to defend against smart bombs and 100kW laser weapons. Since we have no real understanding of the aliens, their motivations or war aims, virtually any strategy or tactic that could be devised becomes meaningless. We have literally no information to work with outside of initially inexplicable goings on in the local stellar neighbourhood, which could even include such events as suns being destroyed by single "shots" of energy directed from outside of the galaxy. Even trying to describe what is happening is virtually impossible to contemplate. The closest SF writer that I can think of is Steven Baxter's Xelee sequence of novels, with FTL/Time travel weapons, black hole "guns" and other exotica. The other issue which hasn't been touched on yet is just what sorts of physics are in play? If the aliens are restrained by General and Special relativity, then the Andromeda Galaxy has been targeting and firing based on information 2.5 million years old, and the results of their actions will become visible 2.5 million years from now. If they have FTL technology, then they also effectively have time travel, which has many issues of its own, including the ability of either party to effectively erase us from the timeline either by accident or on purpose. The only remotely realistic response to this is for the KII civilization to scatter and disperse their civilization across the home galaxy and the globular clouds orbiting the galaxy (at 40 kiloparsecs from the galactic core, you should be safe from most collateral damage). This could be considered the "cockroach" strategy, be widely dispersed and capable of feeding of the detritus of the war and whatever local resources come to hand. The splinters of the KII civilization which make it to the globular clusters will at least have tens of thousands of stars in close proximity, which will allow them to grow to a K3 civilization with the available energy, in case they get sucked into the war. [Answer] We can examine what a full K-type "difference" looks like in the current context. While we cannot look up yet (there are no K-type 1.7+ civilizations as far as we can see), but we can look **down**. Humanity is K-type 0.7 as of 1973, and since then has added rounding error. So we are talking about what a modern industrial war looks like to a K-type -0.3 civilization. Negative? Yes, K-type is logarithmic. [According to Carl Sagan](https://en.wikipedia.org/wiki/Kardashev_scale#Current_status_of_human_civilization), it works out to: $$ K = \frac{\log\_{10}{P-6}}{10} $$ Where $P$ is power in watts. Solving for $P$ we get: $$P = 10^{10 K + 6}$$ or our K-type negative 0.3 civilization has a $P$ of 1 kilowatt. 24 kwh/day. Now, photosynthesis is about 11% efficient, and the sun deposits about 4800 watt-hours per sq. meter per day. Thus photosynthesis captures 528 watt-hours per square meter per day. To generate sustained 1 kilowatt of power, that requires 24 kilowatt-hours per day, so 45 square meters of photosythesis. Supposing a civilization turns this plant matter at a 10% efficienty to useful work (via feeding humans or work animals, and their thermal efficiency). Then you need a civilization with the equivalent of 450 square meters of plant life under intensive cultivation. (This assumes the energy of "keeping humans alive" doesn't count. If it does, the civilization looks more like a single family on an island eating local fruits, living in a cave, and with no access to boats.) Suppose we have a hunter-gatherer society on an island that uses 0.5% of its land area as efficiently as intensive crops, and gets 2/3 of its calories from fishing in the water. Then an island of 30 square km with hunter-gatherer agricultural intensity would be K-type -0.3 civilization, roughly. So Nauru island pre-colonization, or roughly North Sentinel Island today. At most a dozen or few people whose primary power source is mostly wild plants and animals. To reframe your question: as such a civilization, how do they protect themselves from a shooting war between the (current era) USA and an equal strength superpower foe? In that scenario, if there is a war nearby, the superpowers will *accidentally* completely destroy your culture. Even if no weapons hit you or come close, and they are fighting a limited war, if some random excess supplies are aquired their value could exceed your entire economic output of your civilization for as long as you have recorded history. If they use your area as a minor base, more people than your entire civilization will travel through your area, you will be powerless to prevent them from doing anything. They could show up and build something more impressive than your entire civilization's stored capital (and technology level) as a throw-away base in a matter of days, then leave random detritus behind; the parts of the detrius you understand (a small fraction) still exceed your civilizations productive capacity by an order of magnitude or two. What use you could figure out of their tools would be like someone working out how to bend and shape a computer laptop's metal case to form a better spearblade than a bamboo and curt spear. They may seem to sometimes be interested in economic transactions, but they are doing it like a US serviceman might do it with a local on one of the islands. Individuals casually offer to do something at the limits of your civilization's capabilities (like terraform an entire planet, within the limits of a K2 civilization) for some arbitrary price that you see no use for (get about a million people to all jump up and down 17 times exactly while picking their noses in the next hour in a particular city on a particular planet). After you arrange it, they forget to get around to it; when asked, they laugh. A week later they instead deliver 2 complete and new terraformed planets in a harmonic orbit, each mirror-copies of the other, leaving the old one alone. You have no idea how they got there. Your super-weapons can dismantle planets. Their super-weapons can dismantle stars and wipe civilization over 100s of light years, and their *normal* weapons turn the planets of a solar system to dust. Using a different analogy, imagine USA defending against a civilization whose infantry rifles shoot megaton explosives, and the infantry survive the back-blast. Your civilization has managed to encase a single star in computronium at a low density. Jupiter is being dismantled. The sun has been harnessed for its energy efficiently, and you have started colonizing nearby stars. Their large ships are AU or Lightyears in size (mobile battle platforms: no more space ships than a nuclear aircraft carrier is a canoe, not physical objects as much as arrangements of fields), and have populations 10 to 100 times larger than your entire civilization. The odds are against any one of these "large ships" actually coming anywhere near your civilization. A small billion+ sentient temporary base might set up. They'd evacuate your inner solar system, dismantle 10% of your sun, and build a "supply depot". Small fast ships (AU in size) may stop by for resupply. One of them smashes into Jupiter (possibly a navigation error?). Jupiter loses 30% of its mass, scattering debris throughout the solar system and killing trillions directly and indirectly. The alien ship survives, repairs, and leaves. A week later, another ships cleans it up, builds a new gas moon of Jupiter from the loose debris, and smashes together two of the moons, then cools off the resulting location and provides it with an atmosphere and new terran-compatible programmable biosphere complete with beanstalks, but with no creatures from Earth on it. They speak to you, and you think they are asking if the new planet would help, and sorry for the mess. There is no protection at your energy scale. You cannot run, you cannot hide. They don't have to engage in malice to destroy your entire civilization: even casual interaction might do it. All it takes is that they are desperate enough not to treat you with extreme kid gloves and stay away from you for your civilization to be utterly changed, and if a shooting war starts anywhere "near" (where "near" could include distances farther than members of your civilization have explored and returned) you are paste or not based on factors you cannot comprehend. In short, you can survive through luck. Such a war is, in Ian Banks parlance, an outside context problem: your civililization lacks the experience and tools to even know what the safest thing to do is. [Answer] Do rats care about human war? Other answers have focused on powerlessness and how the Ⅱs may be accidently trampled by the Ⅲs, as (Zibbobz points out) like the source of the expression [*of mice and men*](https://en.wikipedia.org/wiki/To_a_Mouse). But I want to focus on the idea that this presents a background that’s no different than any uncontrollable nature. The rats avoid the battles, and then *find a niche* in the environment caused by the conflict. Burns’ wee beastie was nesting in the human’s cultivated field because that’s where the food is: a hugely dense source of higher grade food than anything found naturally. While not every individual goes unscathed, the mice and rats have made a niche for themselves following human activity, and *also* [spread over the world](https://en.wikipedia.org/wiki/Brown_rat#Naming_and_etymology) and [prospered as a species](https://en.wikipedia.org/wiki/House_mouse#Mice_and_humans). Maybe your K-Ⅱ will [“cargo cult”](https://en.wikipedia.org/wiki/Cargo_cult) the Ⅲs. (See Yakk’s answer for a detailed analysis of this!) Birds follow human farmers plowing a field. Maybe the battles and other infrastructre-related activities will provide **opportunities** for the K-Ⅱ to exploit. From their point of view, the K-Ⅲ’s activities are no different than any other uncontrollable background. They just have to avoid becoming pests. The Ⅱ should exploit the background they find themselves upon, but stay below a threshhold of being [noticed and exterminated](http://www.doyourownpestcontrol.com/mice.htm); or find symbiotic or benign roles. A farmer will care deeply about mice getting into the grain store, but a family doesn’t care about the ants that clean up the litter they left after having a picnic, and the family’s younger members may even throw bread to the birds. Humans did not want the Norway Rats to join them on their sailing ships, but the housecats were invited. The Ⅱ might adapt themselves to a niche that one or both of the Ⅲs *welcome*, perhaps to deal with *other* Ⅱs that have gone the pest route. The bird following the plow I mentioned earlier: if it’s picking up what the farmer is sewing, it may end up being dinner for the farmer or killed just to stop it from interfering. But if the farmer is turning over the previous crop and exposing worms and grubs and deeply burried tender roots, he won’t care about the birds picking at it. The successful bird is the one that knows the difference. If the birds go after [burried larva that would have eaten the new crop](https://en.wikipedia.org/wiki/Phyllophaga#Diet), then they might be welcomed by the farmer and rewarded in addition to being in a symbiotic niche. This has been explored in fiction before. [*The Men in the Walls*](https://en.wikipedia.org/wiki/Of_Men_and_Monsters) comes to mind, but it’s not on the scale of the OP. The background of Stephen Baxter’s Xeelee Sequence is close: Cultures are divided on whether to interfere with the activities of a super civilization or assume that they know what they’re doing and leve it alone. [Flux](http://www.goodreads.com/book/show/100681.Flux) for example concerns an entire civilization, “fallen” from the colonists who adapted life to exist inside a neutron star in a gas of superfluid neutrons. The whole colonization effort (long forgotton by their descendents) was for a single shot in the war, engineering the neutron star to mess up some other megastructure of cosmic string. [Answer] Here is some perspective. Human power consumption is 1.23e13 W or 3.87e20 J/year. An 1 Megaton nuclear weapon goes pop with 4.2e15 J of energy, or 5 orders of magnitude less than our yearly consumption. A type III civilization can harness the power output of a galaxy, or 4e37 W = 1.3e45 J / year. At the same ratio of power, an alien super-weapon would hit with 1e40 J of energy, just shy of the binding energy of the sun, or in more stark terms, greater than the energy released by converting the entire moon's mass to energy. So these aliens can one-shot our sun. What are we going to do to stop them, even at Kardashev II? [Answer] "Safeguards" is impossible. A type II civilisation cannot meaningfully threaten or bribe a type III civilisation: they can take anything they want from us without our being able to do anything meaningful about it. If the civilisations are "civilised" in the sense that they try to avoid unnecessary destruction, then they might leave us alone if we ask nicely. If, however, either of them glories in destruction of the weak, drawing ourselves to their attention just gets us killed faster and more thoroughly. They are aliens, not humans. This is why knowing more about the type IIIs is vital to formulating any kind of strategy. [Answer] How advanced their computing capabilities are? If *they* are as ahead in computing department as in energy department, whatever tactics you devise would be transparent to *them* because they can simulate your whole civilisation reliably enough. If all of you prefer to live in the world where more advanced agents play nicely with less advanced agents, you only need to be of no military interest to either side and hope that day will not come when your atoms could be used in some promising attack. Luckily, your civilisation is too weak to bother with. Dispersing - just in case - looks fine. Also, if you have some reasonably sure means of destruction, you could try looting stuff that is obviously garbage for *them* but is good enough for you. Asking both sides just in case would be nice too. Make sure to equip your storages with some self-destruction devices - if you've claimed some stuff then there's no point in trying to get it from you. Sure, you can not defend it, but you won't give it away either. For concievable example, 100 tons of scrap metal dispersed over some large area is a thing not worth bothering with, same 100 tons of scrap metal in one storage is a somewhat of an asset. ]

[Question] [ Meet Greg. Greg was born with pretty average genetics. It seems like he was destined to have average intelligence, average strength, and be average at everything. There was one particularly though: he has **unlimited** willpower. Willpower is the ability to resist short-term temptations in order to meet long-term goals. Having unlimited amounts of it, Greg can, for example, withstand any amount of torture (although he will still suffer trauma), exercise until his body collapses of exhaustion, refrain from eating until he faints, or ~~even hold his breath until he passes out~~ (actually, holding your breath before you pass out may be prevented by subconscious mechanisms, so nevermind), if he so chooses. Of course, these are just the most extreme though not very useful examples of his powers. More practicality, he can break any bad habit or begin any good habit by just deciding to do so. He is immune to addiction. He can do something boring for any amount of time he chooses, such as learning about something he's not particularly interested in, exercise for any amount of time he chooses (if physically able), follow any code of conduct to the best of his physical ability, etc... This of course allows him to be a superhero/supervillain (depending on his goals) similar to batman. He would likely be super intelligent, super fit and strong, have lots of skills including leadership, etc..., since these would likely help him advance his long term goals. **My question is**, what is the most plausible way Greg could exist? It could be either natural or artificial. I think the most plausible answer is some sort of medication that completely suppresses one's desire to complete short term goals instead of long term goals. Another possibility would be that Greg was born with some brain deformity to the same effect. This has the interesting side effect that when Greg takes the medication/when he is born, he may completely disregard things like food or water (which would obviously be life-threatening) until he figures out that he needs to "will" himself into eating, drinking, sleeping, and going to the bathroom, since he no longer is compelled to. P.S. If you use Greg in a story, he could very easily become a Mary Sue. To mitigate this, some possible weaknesses would be stubbornness, odd beliefs or delusions, or obsessions (such as revenge). Of course Greg could get rid of these weaknesses if he wanted to, but the idea is that he probably *wouldn't*. Another weakness is that if you someone how suppress his superpower (for example, by cutting off his medication), he gets extreme avolition. [Answer] # There are real-life examples of this. The example that first comes to mind is that of [Thích Quảng Đức](https://en.wikipedia.org/wiki/Th%C3%ADch_Qu%E1%BA%A3ng_%C4%90%E1%BB%A9c), a Vietnamese monk who poured gasoline on himself, and set himself on fire while sitting still and meditating as he burnt to death, as a protest of the persecution of Buddhists by the South Vietnamese government. You don't need Greg to take drugs; and you don't need Greg to have been born with superpowers. Meditation is *more than enough*. If Greg has been seriously practicing meditation since middle school, I'll give a pass to him doing whatever the hell he wants with his willpower. Warning, potentially disturbing image of Thích Quảng Đức: > > [](https://i.stack.imgur.com/G5YeE.jpg) > > > [Answer] Greg is clearly brain damaged, we know that selectively damaging certain areas of the brain causes drastic and "interesting" changes in behaviour. For example damage to area 24 of the [anterior cingulate cortex](https://en.wikipedia.org/wiki/Anterior_cingulate_cortex) can divorce people from their normal emotional responses to being in pain; they still feel pain normally but they don't get upset by it or feel the need to stop it happening. The effect you're looking for is unlikely to be attainable through a single piece of brain damage and will probably mean extensive damage to many separate areas of his brain. Such damage may occur due to disease but it's more likely that someone deliberately damaged Greg's brain through surgical intervention. [Answer] I started this as a comment, but then it developed into an oblique answer to the question, so I'm posting it as such: ***Everyone* has unlimited willpower.** Most choose not to exercise it. Also: No skeptic can have it *proven* to them that Greg has unlimited willpower. Because he can simply decide that convincing some silly skeptic is not worth his time. Unless his "super power" is the *inability* to change his mind, rather than the *ability* to not change his mind—in which case I'd argue that is a handicap, not a super power. However, let's explore this further: Is it possible for Greg to try to convince others that he *is* addicted, or that he *can't* break a bad habit, or that he *doesn't* have a choice? Of course it is. And it provides such an easy excuse. He chooses some course of action, and someone else doesn't like it. So he apologizes and says, "Sorry, that's a bad habit I have...I'll try really hard not to do it again." And then he keeps doing it. He is perfectly capable of ceasing the bad habit at any time, but *he chose this course of action,* so of course he can just continue it. Calling it a "bad habit" is a way of escaping domination by others. Since he apparently can't stop his bad habit, they probably wouldn't even bother torturing him to try to get him to. (Well, actually, people *are* sometimes tortured for bad habits under the heading of "aversion therapy," such as at the [Rotenberg Center](https://www.cbsnews.com/news/controversy-over-shocking-people-with-autism-behavioral-disorders/), but note that the "bad habit" i.e. the decision wouldn't be changed or cured by mere torture.) He could just keep on with his selected course of action forever under the guise of it being a "bad habit" or an "obsession" or what have you. Honestly, the *real* question is: **How could anyone differentiate Greg from anyone else?** You mention he could do a physical exercise without stopping no matter the pain, so long as he's physically capable. There are such people. He could also *stop* the exercise any time by his own free choice. And he could claim that "the pain was too bad." But he actually *could* have continued, he just chose to stop. This sounds like most people. People take 12-year degrees in subjects they aren't particularly interested in, or spend decades-long careers doing mind-numbingly dull tasks. Take *any* course of action you can imagine Greg doing, and you'll be able to find people who DO take or HAVE taken that course of action. So, again, if you reinterpret your question as a hypothesis that "everyone has unlimited willpower" you will be 100% unable to find a counter-example. It's literally not falsifiable. According to [Popper](https://en.wikipedia.org/wiki/Falsifiability) that makes it unscientific, but it's sure an interesting stance to take. (Notably, it's *also* not falsifiable, and is therefore just as unscientific, to claim that there exists a person whose willpower is limited—we've just all socially agreed to accept that willpower is limited as a matter of course. That way, we can hold on to our own bad habits.) ;) --- As for him being super fit, super intelligent, a super capable leader—perhaps. But it's also just as likely that he would *not* be, in order to win an argument. > > John: We're making you the head of research because we know you're smart enough. > > > Greg: I don't want the position. > > > John: We're appointing you anyway. Don't pretend. > > > Greg: I'm *not* smart enough. I'm not capable of handling that post. I don't want it! > > > John: Shut up and take it. > > > Greg: *Spends the next 50 years proving he is stupid and that John was wrong to give him this appointment.* > > > Spending 50 years to prove someone wrong and to win an argument is an easy consequence of having unlimited willpower. [Answer] # Greg has more 'volition' in his head A relatively famous study from [Baumeister, et al., 1998](https://faculty.washington.edu/jdb/345/345%20Articles/Baumeister%20et%20al.%20(1998).pdf). The study concerns ego depletion, which is > > temporary reduction in the self's capacity or willingness to engage > in volitional action (including controlling the environment, > controlling the self, making choices, and initiating action) caused by > prior exercise of volition. > > > Please note that volition is the expenditure of willpower on some task. The money quote: > > Taken together, these four studies point toward a broad pattern of ego > depletion. In each of them, an initial act of volition was followed by > a decrement in some other sphere of volition. > > > Now we can see 'volition' as a finite pool of willpower that you have in your head/psyche. So, let us assume that there exists a physical manifestation of volition. Some set of neurons, some chemical component, something, it doesn't really matter what it is. Greg has more of it than you do. ### How does Greg have more? If volition is a physical resource, then there are two possible ways to explain how Greg has an infinite amount of it. Either, Greg 'regenerates' volition faster than other people, faster than he can expend it; or Greg 'burns' volition at a slower rate than other people, less quickly than it is regenerated. Or, both can be true. [Answer] TL;DR: Greg's subconscious is weak, or is under control of the conscious mind. @kingledion is correct in pointing you to Baumeister's research. There is more in his popular-science book: [https://www.amazon.com/Willpower-Rediscovering-Greatest-Human-Strength/dp/0143122231](https://rads.stackoverflow.com/amzn/click/0143122231) Here are couple more books: [https://www.amazon.com/Nudge-Improving-Decisions-Health-Happiness/dp/014311526X/](https://rads.stackoverflow.com/amzn/click/014311526X) [https://www.amazon.com/Thinking-Fast-Slow-Daniel-Kahneman/dp/0374533555/](https://rads.stackoverflow.com/amzn/click/0374533555) It was a while since I read them, but I have an idea based on what I do remember. Impulsive and addictive behaviors happen b/c they release dopamine into the brain. Dopamine tells the brain "you are doing the right thing", and make the person feel good about themselves. What releases the dopamine is the sub-conscious part of the mind. It evolved to encouraged a person to do things that improve chances of survival despite no immediate benefit: e.g. social interactions mean you are part of tribe and will have easier time surviving, and finding food when you are not hungry means you are less likely to go hungry later. In modern society, these instincts power addictions: to sex and social media make your subconscious think you are part of a tribe, and gambling or videogames make you feel you are collecting valuable resources. **But Greg got over it**. Either his subconscious does not release dopamine at all, or he learned to suppress/control/redirect his subconscious instincts. "No dopamine" might be causes by genetic mutation, radiation, or physical trauma, and it might have nasty side effects: <https://en.wikipedia.org/wiki/Dopamine> Edit (thanks to RToyo for suggestion): I should have said "no dopamine from satisfying subconscious cravings". He can still get dopamine from the events that his conscious/logical mind views as good. Weakened subconscious could be results of psychological trauma or abuse: all social and random events are negative; the only positive outcomes come from his own thinking and control. Control over subconscious can be learned (see the books). One trick is to associate unwanted behavior with negative feelings, e.g. if your body starts craving a drug, think about drug addicts and how disgusting they are. And then redirect your dopamine craving to exercise, which releases dopamine directly ("runner's high"), and lets you daydream about how strong and muscular you will be. The cost of doing this is slower thinking (subconscious is fast), less happiness, and more stress. You can have Greg go berserk occasionally. Finally, if you want to get more sci-fi'ish, you can have Greg directly control dopamine release, and time it with things he considers a successes. Or he was a subject in a program that did that. PS I should take some of my own advice and break my addiction to WorldBuilding.SE :) [Answer] "Infinite" is not a word that should be thrown about. It's the kind of word that initially leads to questions like "Can Greg stop the progress of entropy with will power alone?" and progresses onward towards questions like "Can Greg overthrow God" or similar questions tailored to your religion of choice. If we sidestep "infinite" and just look at people with really strong willpower, there are examples of people who do what you say. **The top of that scale consists of people whose willpower is so strong that they will spend their entire lives pursuing something, and when they die you get the distinct impression that they're not yet done pursuing it.** Indeed, this will actually be critical for constructing Greg. If Greg spends most of his efforts on something that he can achieve within his lifetime, he will rapidly turn out to not be so average. He needs to be looking one step beyond his own life to appear average to the unaided eye. The Eastern cultures have characters such as these in plenty. You see them in the Western cultures too, but in the West we tend to recognize that which the person did accomplish rather than what they strove towards, so we don't raise them on the same pedestal. An example I remember reading about was a yogi that had completely mastered his startle reflex. Startle reflex is the jerking motion we make when surprised, such as when a loud noise goes off near us. It is preparing for the unknown assailant. There was a researcher who was looking into this reflex. He had put together an audio device that played a sound like a gunshot. From testing it on police and military and others, he had found that it was loud enough and unexpected enough that *everybody* startled. So he went out to find people who might not be startled. He went to Nepal and was directed to a yogi who lived in the mountains. The yogi agreed to be tested, put the headphones on, and listened. When the sound went off, the yogi didn't flinch at all. He simply smiled. When asked to describe it, he described the sound as "clear as a bell." I say the West doesn't put these people on the same pedestal, but there are cases where we do. You mention resisting torture, and that's one case where we do appreciate it. **If you look back through religious history, you'll found countless souls tortured to death for their beliefs. They had enough willpower to face torture and death -- it is hard to argue there's a higher level of willpower than that.** **A common pattern I see in such characters is that they all have the "never move backwards" mentality.** They may approach their goal very slowly, limited by things such as their frail and aging body, but they never move away from their goal. They're constantly rolling and sliding and finding every which way to take one step closer to their goal. Never back. A word I have been given for this is "yielding," and the phrasing I have been given for it it is "yielding is using your opponent's force to move you to a better position." I do believe this yielding pattern is crucial for a character like Greg. **Willpower on its own doesn't cause anything to happen, unless it is coordinated with the movement of the world around you**. When you are opposing the world, it is essential that you not lose ground, and you simply wait for the opportune moment. I also notice characters such as this have a very fluid concept of waiting for the opportune moment. They don't wait for the seas to part and put their goal in sight. They're *constantly* maneuvering with every cell in their body, trying to find a better position. In martial arts, they're not waiting for me to lose balance. They're waiting for my wrist to be slightly out of position, and then they jump on that mistake just enough to let them apply their willpower towards my elbow. If I keep control of my elbow, but lose control of my shoulder, they wont sit back and wait for me to lose the elbow. **They'll happily jump one step closer to their goal without caring which step I presented to them.** Daring to use a well trodden meme, sending Greg to a monastery that specializes in such growth would be the easiest to write way to accomplish this. The Shaolin Monks are famous for their brutal training which instills an amazing amount of willpower. They depend heavily, of course, on the wisdom and practice of the monks before them, which must apply this brutal training regimen not merely to apply it, but with the willpower required to shape a soul with the training. But you don't have to go that far. **All you need is the mysterious mentor who just seems to put you on the right path**. We can find it in fiction books such as Richard Bach's "Illusions." We can also find it all over in reality once we realize we can look for it. You can find it in some celebrity rappers and how they try to raise the next generation of rappers. You can find it in the coach who spends their time at the YMCA trying to keep children off the streets. You can find it in a chess coach who treats chess not as a game, but as a lesson in how to approach life. You can find it in the lifelong pursuit of many fathers, as they strive to raise their child as best as they possibly can. And you will find it in every mother -- it's simply a rule. That's how being a mom works. [Answer] You need look no further than normal humans. What you describe is already a natural part of humanity. ## Your own examples * withstand any amount of torture We will have few examples of this to cite since torture generally is not publically documented. However, we have historical examples of this. Religious martyrs are an obvious one. Other martyrs as well: Braveheart was based on real events, but I'm not sure if the scene at the end is real or not where he is being tortured to denounce the defense against the English occupation and he refuses to do so, shouting "freedom!" instead. * exercise until collapse This is known to happen often. In fact, I have nearly done this myself. I have stopped myself when it has become difficult to stand, but I *decided* to stop since continued activity would not be beneficial. I could have kept going if I decided that there was some good reason to do so. Article: "[Why Do So many Triathletes Collapse Just Before the Finish Line?](https://www.outsideonline.com/2118491/why-do-so-many-triathletes-collapse-just-finish-line)" * refrain eating until fainting People have done more than this; people have refrained from eating until they died, or refrained from eating until someone else force-fed them (and still resisted this force feeding). This is often done as a form of protest. Cite for lots of people hunger striking until they died: [Irish Hunger Strike](https://en.wikipedia.org/wiki/1981_Irish_hunger_strike) * hold breath until passing out This is difficult for many people to do, but I have read it's not because of a lack of willpower, but rather because breathing is not entirely under conscious control. You can prove this to yourself by doing something else so that you are not thinking about breathing and then notice that you still keep breathing sub-consciously. This is also another one that I have personal experience with as well. When I was younger, I wanted to be able to hold my breath for a long time, both to help with underwater swimming and as an impressive party trick. It did not take much practice to realize I could hold it a lot longer than I thought I could. I never did it until I passed out, but again, when I stopped it was because I feared I was doing damage to my body. I once held my breath until the people watching told me that my skin was changing color and darkening. I held it a bit more but then let it out because the viewers were concerned for my health. I started to have the same concern and so stopped by choice. Usually, I was not timed. One time I was timed at about 4 or 5 minutes, but that was not my best breath-hold, not by far. Since my longest holds were longer than that (but of unknown exact duration), we can assume that I was probably close to passing out. I do not consider that super-human, and I assume that there are a *lot* of other people that can do it (albeit a small fraction of the overall population). However, if I was stopped from holding my breath before I actually did pass out, it would not be because of a lack of will power, but rather would be a biological process known as an "involuntary muscle movement". Moving your finger is known as a "voluntary" movement, while heart beats are involuntary. Breathing has aspects of both, so some people claim it impossible to hold your breath until passing out not due to lack of will power but rather due to the involuntary aspect of breathing. ## Other examples * [Aron Ralston](https://en.wikipedia.org/wiki/Aron_Ralston) cut off his own arm with a dull knife to save his life after a boulder pinned him in place You might argue that is not will power since he had to do it to save his life. However, most people would not do it, and many others have died rather than do such gruesome things. I would say it counts as a mountain of willpower. * Emergency responders In order to save other people, heroes have walked into burning buildings and searched for others until they have died trying to save them. Many police have rushed into situations where they put themselves knowingly in great danger of injury or death. Some personal security agents have made a conscious choice to sacrifice themselves for another person. Others have had their security roles (whether professional, or otherwise [love, etc.]) put to the test and shown that they would sacrifice themselves for another. ## Summary It seems that humans have demonstrated that a small fraction of them actually have the power that you describe, or at least close enough that they do the types of activities that you mention and worse. Because there are so many humans around, that small fraction of the populace who practically do have the power you describe is actually a rather large number of people. Many of these people have not induced this power by drugs, nor by brain damage. They are healthy, happy, not diseased (in that manner, anyway), and are normal humans who possess this ability. [Answer] # Greg's friend is Willy Greg indeed have a very powerful willforce. So powerful that it deserves a name. Lets call him Willy! Willy is Greg's imaginary friend (and sometimes not-so-friendly). Greg literally sees Willy around all the time. Wherever he go, whatever he does, Willy is with Greg. However, although Willy is imaginary, Greg has very vivid hallucinations about him. Willy however, is extremely bossy, manipulative, selfish, sadistic and cruel. Say that Greg is too tired to keep running and is thinking about stopping for five minutes. Then Willy will react with violence and severely hurt Greg. Although the hurting is imaginary, Greg feels severe pain from that. So, let's suppose that Greg is being tortured to be induced into saying something. Greg will actually feel the torture at least doubled, because Willy would also be torturing Greg to a greater extent to make him not say anything. If Greg needs to study calculus and is tired from that, whenever Gregs put the eyes out of the book due to tiredness without a very good reason for doing that, Greg will see Willy punching his face and actually feel all the pain from that. Going back to the book makes the pain immediatelly disappears and makes Willy happy! However, although cruel and violent, Willy is always working hard to ensure that Greg is focused into reaching his objectives, so he is friendly afterall. Greg do not talks directly to Willy, because Willy seems to be able to read his mind (in fact, he is part of his mind). Also, Greg is intelligent and acknowledges that Willy is imaginary, so he won't present him to somebody else. In fact, he is unlikely to be able to mention anything about Willy to somebody else because Willy wants Greg to be sucessful and most people won't be successful if they talk seriously about their imaginary friends to other people. This means that it is very unlikely that other people acknowledges that Greg's features an imaginary friend and everybody will perceive him as an extremely determined person. But in fact, Greg is a severe paranoid schizophrenic person. [Answer] Another way of looking at this would be to have Greg possess the ability to *truly* calculate costs and benefits, relative to his own personal situation - in the way that some people have "perfect pitch" relative to sound. Willpower is generally seen as required to undertake some action that benefits you or is of use to you, but is unpleasant in the short term. When you experience a "failure of willpower", it's because you are overvaluing the short term unpleasantness and undervaluing the longer term benefit. If you simply *never did that*, you would not need what we call "willpower". This would grant Greg the ability to perform the feats used in your examples, but only in specific situations. He would be able to exercise until overcome by physical exhaustion, but only if it made sense for him to do so from a cost/benefit perspective. (Perhaps he would do this to win a bet, but not merely to prove that he could?) [Answer] Perhaps Greg is overly sensitive to adrenaline affects, even when compared to an Adrenalin Junky. This would create both a condition where he could will himself through anything as the small release of adrenaline from motivating himself would result in a stronger drive to stay on target or keep it in. Since he can get more response out of smaller amounts, it isn't that he's immune to dopamine, but that dopamine release by adrenaline (which is where the Junky aspect comes in) would not occur and he'd be less likely to become addicted to reckless behavior. In fact, he'd be prone to some incredible feats of strength compared to base line humans because adrenaline is linked to hysterical strength (the term for a phenomena where a life and death situation would cause people to show incredible feats of strength that they ordinarily couldn't achieve. The typical story is of a mother being able to lift a car off her son, who was pinned under it). This also comes with a down side and it would be one he would have to be aware of and mindful of: a state of hysterical strength is an emergency override of a biological safety feature... think of it as a natural strength limiter so we don't hurt ourselves. Running at constant hysterical strength level would actually do a lot of physical damage to the human body... just like red lining a car would actually start to be detrimental to the engine. So Greg's feat of strength could actually do a lot of damage to himself if he was in a big superhero fight for a long period of time. If he is overly sensitive to Adrenaline, than introducing any level of stress to Greg will actually start to put him in a red-line state. He would need to take a lot of the same precautions Bruce Banner does to stay calm for a very similar reason... just when Greg gets angry, he doesn't go green. Another thing is that the Hysterical Strength level is also a "heat of the moment" response... basically the person exhibiting the feat isn't trying to... they are so hyperfocused on the task of saving their buddy that they don't realize they are actually successful in lifting the car. This could put Greg into a "beserker state" where his will is so targeted at the task, he effectively loses situational awareness, opening him up to some really bone-headed sneak attacks or possible endangerment of partners. If you watch any cop show, this kind of behavior is followed up by a scene where Da Chief reads the cop Da Rules and asks for his badge and his gun and tosses him off the case. And for good reason, as detective work requires emotional checks... you may violate some rules that are there for good reasons because of the emotional investment you put into it. Too anyone Greg has to work with on a superhero team (and he seems more suited for Super-Teams than Solo work. Superman he ain't), Greg is going to have difficulty getting along well with a leader barking orders without understanding that Greg is a sledgehammer, not a scaple. For maximum drama, there could be someone else on the team who gets what's going on and would have to defend Greg when his hyper-focus messes up. Heck, Greg will need to employ every distress technique he has to keep from putting team leader through a wall. Additionally, Greg could get some humor and bizarre conflicts as a minor issue as well. Since he is always hyperfocused on the task, there could be a scene where Greg is walking through the Halls of Justice in a Tartan Kilt and hat (wearing everything a Scottish man does under the Kilt). When question on why he's doing this, he'd give a quick response of "Decided to learn to play the Bag-Pipes Today," and leave as if that satisfies the question (Which it doesn't). And then the team has a miserable day at the Halls of Justice because Bagpipes are not indoor instruments and no one can tell if he's really good or really bad at any given moment. [Answer] **Greg is the opposite of ADHD. Greg's brain produces an abundance of dopamine while concentrating.** Dopamine is a neurotransmitter that is responsible for a whole lot of things in the brain. It is perhaps most famous as a "pleasure and reward" inducing neurotransmitter that drugs like marijuana and cocaine stimulate, but it is key for all sorts of things, from attention to learning. Until [a few years ago](https://www.cam.ac.uk/research/news/imaging-study-shows-dopamine-dysfunction-is-not-the-main-cause-of-attention-deficit-hyperactivity), it was pretty well agreed that, in simple terms, ADHD behavior was [linked to reduced levels of dopamine](https://www.healthline.com/health/adhd/adhd-dopamine) in certain areas of the brain. I won't get into the details, but the over-simplified/partially-wrong idea is that a lack of dopamine makes the current task uninteresting/unenjoyable/understimulating, so your brain seeks out other stimulation. If you start with the (somewhat incorrect) view that ADHD is a lack of willpower, and your goal as a writer is to come up with a way to increase willpower, then increasing dopamine levels in the brain may be a way to induce more willpower. In fact, that's what ADHD medication does - amphetamine-containing drugs like Adderall and Ritalin increase dopamine levels in the brain. You could then make the hand-waving jump to the explanation that when Greg concentrates on what he is doing, his brain begins releasing more dopamine to key regions throughout the brain, such as into the limbic system where it will help Greg focus, and increase the brain's sense of reward for doing whatever he is or is not doing, allowing him to continue what he has set his mind to, and reinforcing any habits. **Personal thoughts:** Personally, I would not try to root this "power" on science. The brain is incredibly complex, and there are so many different (and competing) reasons for any given behavior or motivation (such as the willpower to diet vs the willpower to read a textbook), that trying to root it in biology would result in a completely different brain and nervous system than what a human has, and it would make Greg pretty non-functional. More directly, the concept of "willpower" does not translate to things that are controlled by the autonomic nervous system (such as breathing, hunger, or tiredness), nor is consciousness itself a good way to monitor willpower (your brain brings many things to your conscious attention, but the decision has been made long before it reaches your conscious thought). It's similar to someone having psychic powers - you're better off just coming up with a hand waving/sci-fi explanation, than to try and root it in hard science. **Some common disorders you could research:** * ADHD is a good disorder to research for "attention" willpower. * OCD is a good disorder to research for the brain overriding willpower through intrusive conscious thoughts. * Addiction is a good disorder to research for how the brain hijacks survival areas of the brain to motivate behaviors "below" conscious thought. * Autism has a very broad array of symptoms, but it may help understand why a person is able to maintain interest. * Bipolar disorder, specifically the manic symptoms, is a good demonstration of why too much dopamine in the brain is NOT a good thing. [Answer] ## What is Willpower Really? We don't say we are exercising willpower when the choice is easy or obvious. In an election of reactions to some stimulus, when a weaker idea wins out over some of the stronger ones, that is when we usually say that willpower is being exercised. ## What is Suppression Neurologically? There is evidence in the brain the some neurons [suppress the behavior of their neighbors](https://en.wikipedia.org/wiki/Surround_suppression). The brain slowing down it's own reaction seems to allow things such as depth perception and better pattern recognition. This demonstrates the the brain has the ability to learn to still feel the impulse to respond to a stimulus while, nevertheless, not allowing that "learned-not-to-do" impulse to reach the final decision-making layer of how the brain processes a problem. Surround suppression lingers longer than an immediate signal. This is indicated by changes to visual responses being held back for longer than a single time slice. At this point I can not point to published research (this is my own idea) - I believe if you are exposed to a great deal of need for suppression (a lot of tough choices over the course of a day) your brain ends up incrementally suppressing more and more of itself until there is some downtime for the system to reset. This would mirror the "erosion of ego" over the day that kingledion referenced in his great answer (from [Baumeister, et al., 1998.](https://faculty.washington.edu/jdb/345/345%20Articles/Baumeister%20et%20al.%20(1998).pdf)). We also tend to ruminate - going over the same situation in our head long after the decision has been made - which would mean the brain has to suppress those other ideas for a longer period of time. Rumination is part of the brain's process to reconcile new experiences with the whole so that we learn. However, it likely requires prolonged suppression by those neurons to keep us from rushing back to reverse or reconsider our earlier tough call. ## How Could Greg Be Different? Greg could possess an overabundance of whatever chemical or process ends surround suppression. As a result, there is probably some threshold at which enough tough decisions start to pull Greg down, but that amount is much higher than a normal human could hope for. He would recover from the drag of tough decisions much more quickly. He might not be doped up on hormones, or damaged by a lack of empathy. Instead, he might be encountering each difficulty with a clear head, but just not dragged down by it. [Answer] Greg is a robot, or perhaps a cyborg. He does exactly what he is programmed to do, and is not subject to temptation or distraction, or self-preservation instincts. ]

[Question] [ Recently I noticed how space fleets are all constructed so the ships are all aligned. With 'aligned' I mean the way how all ships seem to have a 'right way up' and that all the ships have the same sense of 'down', even opposing fleets, even when in deep space. Is there any reason why spaceships would adhere to this 'universal' orientation? Edit: The question came more-or-less out of thin air, I am primarily interested in how one would justify it without having to invent lore. [Answer] The crews have evolved on worlds with orientation, so their psychology and conventions reflect the reality that they are planetary creatures. Orson Scott Card captured the importance of orientation to human psychology very well with his "The enemy's gate is down" line in Ender's Game. Changing the perception of orientation changed the psychology of the strategies in use. Instead of working from a perception of inferiority due to being outnumbered, they worked from a perception of positional superiority to offset their weaknesses, even though the facts of the battle had not changed. Even though "orientation" may have limited practical applications in space, the psychology of living beings demands an orientation for the purposes of communication and conceptualization. Even in unlimited space, beings that evolved on planets will tend to gravitate (no pun intended) to formations inspired by two dimensional thinking. [Answer] # In our world When you watch a movie, the ships are usually aligned. This is because of reasons that are most likely not based on our experience in space battle. I'm pretty sure I read about this and I will update if I find the reference. Here are some reasons: * Visual aspect. A viewer is expecting that an organised fleet of spaceships will look, well, organised. If all the ships were facing another direction, some up, some down and everything in-between, then it would look like a random mess. Nearly as if the fleet had suffered a problem and were not battle-ready. [](https://i.stack.imgur.com/MFZ1h.png) * In movies, armies of barbarians wear random colours and are not well aligned. A proper army is wearing uniforms, move as one man and is well aligned. [](https://i.stack.imgur.com/553fe.jpg) * The humanity likes to see aligned things. The movie spectators as well. * Experience in sea battle. What might be intuitively closest in our experience to a space battle is a sea battle. Sea battle very often were lines of ships passing along each others and shooting. The bigger battleships were even called "[Ship of the line](https://en.wikipedia.org/wiki/Ship_of_the_line)". [](https://i.stack.imgur.com/TQV7h.jpg) * Classical view of battles. Before the first WW, the typical way of fighting was to align people in front of each other and make them shoot or advance toward the enemy to engage. (Or at least it is what we think about it.) [](https://i.stack.imgur.com/QjxfR.jpg) All these points might have influenced our idea of what a battle should look like, and is hence what we get in movies and other fiction works about space battles. # In your world On the other hand, your question might also be in-universe, which means applying the logic and the rules available within a story. So, if the ships of your world are well aligned, it might be because of one of these reasons: * It's the early age of space battle, so generals don't really know what to do and try to hide it by spending energy on aligning the ships. To them, a well aligned fleet is the sign of a good general. * Weapons and shielding are mainly at the front in order to save weight. So you want the front of your ships to face the enemy. If both fleet are applying the same logic, you get two well aligned fleet. (Until the hero comes and decide to attack the enemy from behind and then the strategy changes). * Similarly, propulsion is at the back, so if you want your fleet to be able to accelerate in one specific direction, they need to be aligned. * Coordination. If someone shouts "Watch out, missile coming from above!", then you want everybody to look in the same direction. Same with the order "Ship XXI, move forward"!. * Because of all the points in the first part of my answer, a well aligned fleet could impress the enemy more and ruin its morale. * They are all coming from the same point. For instance if all the ships were attached to a structure facing one direction and they all moved along the same path to get to the fighting scene, then they maybe simply had no reason to turn. [Answer] **Are you asking from the POV of TV shows and Movies?** TV shows and movies always show fleets approaching one another in the same orientation and on the same plane. Why? For the convenience of the viewer and to better express the drama of the moment. The chaos of a true 3-D fight is very difficult to follow on a 2-D screen. An example might be the opening battle sequence from Star Wars, *Revenge of the Sith,* where a 3-D battle is briefly shown with a quick transition to focused views of Skywalker and Kenobi flying their fighters. Just enough to let the audience understand the chaos, then shift the point of view for easier viewing (allowing the movie to focus on dialog). Note that even that battle wasn't as chaotic as it could be. I'll mention that in a moment. My point is, while humans see in 3-D, only experienced military fighter pilots have a grasp of 3-D combat — and even that's affected by the fact that they're flying over a gravity well. I'm thinking of a quote from Mr. Spock from *The Wrath of Khan,* "he's intelligent, but inexperienced. His patterns indicate two-dimensional thinking...." **The real thing: gravity wells** In reality there would be a lot of navigational complexities affecting the nature of 3-D fleet combat. The most obvious is a gravity well. Unless your world uses gravity-nullifying technology (crews always experience "down" with the correct amount of force), the natural habit of pilots would be to orient the ships for the greatest opportunity for the crew — which means orienting the ship so that the floor is between your feet and the planet. The closer you are to a gravity well, the greater the tendency to do this. Where you see 3-D combat taking place in this situation is very much like terrestrial fighter planes: altitude. Your orientation may tend to align with the gravity well, but your combat is taking place at different altitudes. **The real thing: Open Space** Let's go to the other extreme: deep space. Not a gravity well worth mentioning in sight. In this case, your combat has more to do with approach vectors and the design of your ship than anything else. This would be the most chaotic (from a 3-D perspective) combat. Ships flying upside down in all sorts of directions, etc. Anything goes. Kinda... You see, most of our fantasy ships are designed from a 2-D perspective. The ship has a keel, somewhat like an ocean-going vessel, guns are mounted along that keel or axis. There's a "front" and a "back" and the engines are at the "back." They're long, flat, and there's a distinct "down" to the design that's almost always represented by the "bottom" of the ship. Even the design of the spherical Death Star from Star Wars was a series of laterally-oriented floors or decks from the "bottom" of the sphere to the "top." What this means is that your combat will conform to how you can bring your weapons to bear. If you're flying a Star Wars "Star Destroyer" or the U.S.S. Enterprise, your orientation can't really be universal without serious mobility of the turrets/launchers. You can get around this to some degree by using, for example, heat seeking missiles, which remove orientation as a factor of launch, but your beam weapons are limited by placement. Therefore, to really enjoy the orientless nature of deep space battle, you want a spherical ship with concentric decks where "down" is the geometric center of the sphere. Weapons are mounted uniformly on the surface of the sphere. The sphere can enter battle from any direction, move in any direction, rotate in any direction, and perform its tasks equally well. **The real thing: rocks** Space is big. Really big.*Citation Needed* as a consequence, outside of gravity wells you're actually unlikely to encounter anything. Asteroid belts aren't the densely-packed fields of boulders we see in the movies (if they were, gravity would pull them together to form planets). Planetary rings are nothing at all like what was shown (delightfully, I might add) in (if I remember correctly) *Star Trek* (2009) when the Enterprise comes out of warp in what looks like an opaque soup of gas, to rise out and save the day. It looked cool. Rings are nothing like that. That doesn't mean there aren't rocks to be avoided. Terrestrial fighter pilots are moving so fast they are forced to care about where mountain tops are. Mountain tops don't occur very often — but when they do it's, um, *inconvenient.* Rocks are the same thing. You'd be on constant look-out for the little bounders because your deflectors are probably designed to move dust aside, not rocks, and certainly not boulders or things the size of a mountain. Why do these rare events matter? Because they create a plane upon which combat takes place. That rock, (because we grew up running and playing in a gravity well) will quite easily be interpreted by our minds as "down." Something we want to be "away from." It would be believable (but not required) for combat to begin forming along 2-D lines should a big old rock be found in space. Which leads us to my last entry.... **The real thing: debris** I suspect space combat will result in a lot of debris*Citation Needed* that doesn't conveniently fall to the ground.*Citation Needed* That debris is theoretically chaotic: expanding in all kinds of directions. Because of this, you'd think that it would force combat to an even more chaotic, orientless, 3-D condition. Well... maybe... Combat isn't as chaotic as one might think. Strategies are being put into play. Organized and intentional maneuvers are used. This means the debris field is developing and being manipulated in complex but theoretically predictable patterns. As the debris field grows and our natural childhood-driven tendency to see it as "down" or something to "stay away" from takes hold, it is (in my mind) quite believable that combat begins to develop on 2-D planes (-ish. That would be an awfully simple way to model a very complex situation, but I think you get my drift here). The "plane of debris" or "surface of the debris cloud" would force the battle, giving it a "down." **Conclusion** But, to conclude, I personally think ship design and our personal perception of gravity has the greatest affect on whether or not space combat has an orientation or alignment. Engines will be seen as "back." The first time we're given a database on any particular ship, its design will be presented and we will assume the top of the screen represents "up" and we'll pretty much always think of it that way forever more. Mostly because we grew up on a planet where there was a distinct "down" and "up." You might not have noticed yet, but how we're trained to perceive our universe as children is actually a very hard habit to break — which is one reason why just any terrestrial pilot cannot be a successful fighter pilot. But, in your world, if you design your ships to take advantage of 3-D, you'll find that training will follow and the tendency to impose order on chaos will dissipate. With the exception, as I said, of gravity wells. If you don't have a way to remove them from the picture, the planet below will always be "down." Childhood — a very hard habit to break. [Answer] There are some practical reasons for organizing a fleet in a space battle: 1) You don't want your T crossed. This is what happens when many enemy ships can range on your lead ship but only your lead ship can range on the enemy ships. If you fail to meet the enemy fleet basically as a plane your T gets crossed at least for a while. The more combat involves beam weapons the more important this becomes. (Note that if you have any non-combatant ships along they will be behind this plane.) Note that movies tend to get this wrong--your fleet should be in a 2D plane, not a 1D line, and they should be arrayed in a hexagonal formation, not a square one. 2) Assuming your firepower is any fashion directional (and basically any beam weapon must be directional) you will in general be able to deliver a harder punch if you build your ship with a this-side-towards-enemy design. Likewise, you will put your best defenses on that same side. 3) When the stuff starts flying you will want to maintain communications links with at least nearby ships despite enemy attempts to interfere. (If your sensors are blinded you can engage the inbound with info from your neighbor. If your missile director is out he can guide your missiles.) This will be most secure and reliable if you have dishes pointed at your neighbors. You get maximum flexibility if the fleet starts out with those dishes at the middle of their travel. This means you will be aligned to one of the standard angles for which your fleet is designed to operate. If the mounting space for weapons is a factor then you'll end up with basically cone or pyramid shaped ships, the point towards the enemy. (This assumes there's nothing about your tech that forces some other shape. For example, in the *Honor Harrington* universe the drive forces ships to be long and narrow.) Which of those angles is only relevant if humans actually relay data as part of the communications. If someone is going to say "fighters coming in high" then everyone needs to have the same definition of what up is. If all such communications are "fighters!" and a data packet showing where they are it won't matter which angle you are at. [Answer] Actually, orientation is very important even in space because coordinated movement is difficult to achieve without a common frame of reference. To give a simple example: To avoid midair head-on collisions, airplane pilots are instructed to [change their heading to the right to avoid collision](https://aviation.stackexchange.com/questions/3575/which-way-should-you-turn-to-avoid-another-aircraft). Such a rule makes perfect logical sense under normal circumstances, but suppose that one of the planes was upside down, and they both still decided to turn right: In that case, they would crash. It follows that having a common orientation would be critical anytime when a human pilot would be expected to follow standardized flight rules, even in space. [Answer] Because they are fighting in orbit. There's actually little reason to fight in deep space. There's nothing there to fight over and if you tried to intercept an oncoming fleet on its way to your planet or asteroid you'd end up whooshing right past it with a split second interval to exchange fire. But planets provide an automatic thing to orient yourselves to and you're going to want to put the smoother side of your ship if it has one toward the planet to reduce drag if you end up skimming the upper atmosphere. [Answer] Because front and back. Making the assumption that the fleet operates on what is (Star Trek) called impulse power, such propulsion typically (as far as "typical" applies to imaginary subjects) has a fixed thrust vector relative to the ship orientation. In plain language, you point the nose in the direction you want to go, and *something* comes out the back to make you go there. If the fleet is going to maneuver as a fleet, everybody has to point in the same direction. So that takes care of one axis. As to other axes, there is no apparent reason to think that all of the ships *will* orient themselves the same way. For instance, it would make a great deal of sense to concentrate all energy point defense weapons on one side of the ship, then keep that side pointed toward the enemy. So a fleet would proceed with the strong side (let's call it the top) pointed away from the center of the formation. To do otherwise is to reduce the effective firepower caused by other ships masking their lines of fire and/or fratricide. Of course, in movies and such it looks cooler and more like the naval formations we're all familiar with if everbody has the same orientation, and the Rule of Cool is the real, underlying cause for an awful lot of what you see in the movies. [Answer] SciFi writers on the ground had to use naval-style to do space ships, because it was the only thing they had to use as a reference. Anytime someone asks "why do people do something archaically when it could be more advanced?" I think of the old Bugs Bunny "House of the Future" cartoon... where when a dish gets broken, a robot comes out to sweep the floor with a broom. The artists of the cartoon had no concept of a vacuum. They just figured robots would replace human manual labor, and there wouldn't be any innovation in the manual labor done, though (ie: robots would be sweeping instead of humans sweepoing). Same with space ships and space battles. Sci Fi writers had to imagine how epic battles would be fought, and it's easier to do that (and describe it in written word) when you keep it on an XY 2D plane where ships face off against each other like two sides on a battle field. When you include the Z direction of the 3D plane, it makes for much more intricate maneuvers, and makes traditional space ships seem awkward in having a "top" and "bottom". More and more sci fi coming out figures that ships will simply be centrifugal in shape, having a gravity deck that circles the core .. so there won't be an up or down, but still have a front and back. While we're on the topic of space battles, we could also ask why super advanced space ships are so awful at hitting anything with their turbolasers? We have advanced machine learning today that can predict where targets will be and hit them with pin-point accuracy. Surely advanced space ships will have turbolasers that have auto-targetting that's good enough to do all the calculations and lead a target and hit it with pin-point accuracy every time? The issue is that some scifi is still trying to tell a space opera story.. so, they make concessions for the story that make no sense when you start picking it apart from science. EG: Star Trek... I always told my friends that the greatest trick Star Trek ever played on people was making them think it was a show about science when it was actually a show about social studies. Every episode is some social situation being addressed, but it's dressed up in sci fi. There are oddities in Star Trek that can get picked apart by modern science, but we give it leeway because it's a show for entertainment, not an end-all / be-all of science accuracy. [Answer] # Zone Criticality and Aligned Weaponry Assuming a functional construction of fictional spaceships, there will still be different regions or "zones" on spaceships, similar to how zones exist in seafaring ships today. These include zones for propulsion, escape craft, armaments, navigation, sensors, command, and sleeping quarters. Zones have varying criticality for the functioning of the ship. In many fictional universes, not all outer-hull material (or force-field technology) is equal. Generally, you want to position higher resilience hull areas towards the expected vector of incoming damage. Alignment therefore has two main purposes: 1. It positions more-critical zones of the ship behind maximum shielding, and, 2. Allows armaments within cohorts to enhance focus firing on specific targets with clean lines of sight A good example of *lack of alignment* as a military tactic is observed in Ender's Game, where the aliens actively swarm around critical defensive positions in order to preempt strategic lines of fire. [Answer] Most spaceships in "space opera" science fiction movies are badly designed. Written science fiction is more likely to use better designed starships than movies and television, but includes many that use the wrong layout. In most visual science fiction starships use some type of generated gravity aboard for convenience in filming scenes with normal weight instead of weightlessness. It is also common in written science fiction but not nearly as much, because writers don't have to worry about the extra expense and difficulty of depicting weightless conditions aboard ship. If a space ship uses gravity generators to generate gravity aboard ship, the designers have considerable freedom, depending on the technical aspects of that highly advanced fictional technology, to arranged the decks of their ship. In most space opera movies and TV shows the decks are arranged parallel to each other so that some are "above" or "below" other decks. Thus one part of the ship's hull is more or less the "top" according to the internal gravity and the opposite side of the hull is more or less the "bottom" according to the internal gravity. And that seems like a reasonable way to arrange the internal gravity and decks of a starship if it is technically possible to generate gravity that works like that. So far so good. But where most space opera movies and TV shows, and many written space operas, goof up is arranging the their space ships like sea ships, with the decks running in the direction that the ship travels, and thus the direction of the generated gravity being perpendicular to the direction of travel. Suppose that the space has to suddenly accelerate and decelerate by several times the amount of the generated gravity, which should be kept at 1 g for the sake of the health of human characters. Characters will be flung forward or backwards with a force of several gs. I remember a story where a character killed another character by turning on the propulsion while the other character was not strapped in a seat. And they were both in the relatively small control room. Imagine walking down a long corridor facing fore and aft when suddenly, without warning, the spaceship accelerates or decelerates at several gs. You will suddenly find yourself in a vertical elevator shaft and fall to your death. Items not tied down but instead held in place by the generated gravity will suddenly fly around and smash into other objects and people. *The Black Hole* (1979) had a large space ship the *Cygnus* with a very long corridor. The *Cygnus* also had rocket engines at the rear. Whenever the rocket engines fired the very long horizontal corridor would become a very tall vertical shaft and anyone in it would fall to their deaths. If a spaceship with that design accelerates or decelerates at several gs, the ship could compensate for that by increasing the force of the generated gravity it uses. But that generated gravity would be working at right angles to the g force from acceleration or deceleration and thus would turn the total g force acting on people and objects in the ship into a diagonal vector somewhere between pure horizontal and pure vertical. But if a fictional starship is designed not like a sea ship but like a skyscraper building, being tall and thin with many decks one above the other, and with the front and the top of the ship being the same part, and the back and the bottom being the same part, it would make much more sense. The decks would be perpendicular to the direction of travel, and so the generated gravity would point toward the back/bottom of the ship and away from the front/top of the ship. The generated gravity would work in the same direction that the ship traveled. So if the ship accelerated or decelerated the strength of the generated gravity could be increased, decreased, or reversed, as needed to compensate for the changing g forces and keep the total force acting on the passengers a steady one g pointed downwards. So a starship with generated gravity built like a skyscraper would probably be shaped like a very tall cylinder. The decks would probably be circular and relatively small, with many levels of decks. So a fleet of space battleships would probably be a bunch of tall, thin cylinders, and probably be arranged in some sort of three dimensional pattern with all the ships in the fleet pointed parallel, with their fronts/tops pointed in the direction the fleet was traveling in. Since the best type of battle is one where you can harm the enemy but they can't harm you, weapons range will be very important in space battles. If it turns out that Fleet A can damage the ships in Fleet B at a distance of up to 1,000,000 kilos but Fleet B can only damage the ships in Fleet A at a distance of 100,000 kilos or less, Fleet B will try to keep the distance between fleets at 100,000 kilos or less, and will head toward Fleet A to lessen the range if necessary, while Fleet A will try to keep the distance between fleets between 100,000 and 1,000,000 kilos and will move toward or away from Fleet B if necessary to stay in the proper range. Presumably the total volumes of the two fleets in a space battle would be a small fraction of the distance between the two fleets, so that all the ships in a feet were firing at the enemy at basically the same distance, just as in the early 20th century battleship battles were fought at longer and longer ranges by fleets widely separated from the enemy fleets. And the hypothetical thin cylindrical starships would keep their fronts or backs pointed at the enemy fleet in order to have as small a cross section as possible pointed at the enemy weapons to make as small and hard to hit targets as possible. Most movie and Television space opera starships use the in my opinion inferior design based on sea ships, with the decks orientated in the direction of travel and thus with the generated gravity perpendicular to the direction of travel. Thus those in my opinion goofy starships have tops and bottoms which are not the same as their fronts and backs, but instead are perpendicular to their fronts and their backs. So when those goofy starships fly forward they have four sides perpendicular to their fronts and backs, a right side, and left side, a top side, and a bottom side. And it seems like there is no reason for two such spaceships traveling together to be oriented with their top and bottom sides pointed in the same directions. Two spaceships travelling side by side could have their topsides pointed toward each other, and their bottom sides pointed away from each other, or vice versa, and it wouldn't matter as long as they were far enough apart for their generated gravity to not interfere. And if a starship coming from star system A happens to meet a starship coming from star system B in interstellar space, there is absolutely no reason to expect that their top to bottom axis would be aligned parallel instead of pointing in two different random directions. If the two starships are travelling under power when they meet, their two fronts should be facing forward and thus toward each other. but if they are coasting through space with their engines shut off there wouldn't be any reason for either ship to keep its front pointing in the direction of travel. I could probably imagine some sort of technobabble explanation for why typical space opera starships based on the designs of sea ships might all have their generated gravity pulling them in the same direction, but I am not fond enough of those goofy starship designs to suggest any sort of justification for them. [Answer] Movies are not the best source for realistic space ship and space warship design. The principle of a space warship are its tight mass limits and the long range at which combat happen, which means your enemy is usually attacking from a single direction, and you want as little armor as possible, forcing you to a long and narrow cylinder, as the sloped armor gives you significant gains. Since your engine is usually not armorable, you want to put it at the opposite side of your armor pyramid, facing away from the enemy. Lasers, particle beams and guns will generally face forward. Missiles can point anywhere, as they can reorient after launch. The orientation for the crew is independent of the orientation of the warship. It could without an orientation, using all four walls equally. A long distance warship will likely start including spin gravity, in which case the internal orientation of the crew is 'down is outwards' since that is where the spin gravity will be pulling objects. [Answer] ## Aligned Artificial Gravity Fields **The reason why such ships have an upside and a downside is because they have artificial gravity fields.** Without artificial gravity, large spaceships would tend to be more rotationally symmetric around their forward axis; as long as they are all moving the same direction, you can't really tell what their rotations are. Gravity falls off by the distance squared, and gravity wells have an additive effect. So it seems unlikely that artificial gravity would be perfectly contained within a ship's hull. If a goofball sideways ship scoots right past you, you feel their gravity well a bit too, and everybody tumbles over like the floor is sloping. And it's pretty hard to do space stuff when you keep falling down all the time. Perhaps your gravity system can adjust for it, but it at least has to work harder to undo the interactions. Either way, artificial gravity ships in a fleet might need to tune their gravity according to the number of ships and their position among them. As for other answers, differing ship sides (e.g. a broadside combat face) is also feasible. Psychological reasons are possible, but weaker; militaries parade with uniform appearance to that effect, but in combat people stop caring if everyone is stepping in time. [Answer] Because we anthropomorphize, even when we try not to. Even when we create alien races that "don't look human" they often tend to have human or Geocentric features - limbs, eyes, mouths, ears, audible language. We do this because it's what we know - it's a baseline. Humans have spent millennia making assumptions about life and intelligence. Along those lines, there's a (reasonable) assumption that intelligent life would come from a planet, and a planet will have gravity, and thus that race would have a sense of up and down, at least. Though there are indigenous cultures here on Earth that think about these things wildly differently as it is (the Guugu Ymithirr are just one example). But what of a race who have come to colonize space itself? Have had no land-bound time in dozens or hundreds of generations? How might they view things differently? [Answer] The fleet are presumably within a Galactic disc with a galactic up (north) by which all fleets could be aligned if all agreed. You'd need to think of a reasoning why everyone would agree to right the tops of their ships in this direction. Maybe something along the lines ships on earth / airplanes agree to both pull to the right when they're in a head on collision. When everyone has different directions for "up" you can't have a full to always turn right when you're heading straight for someone. Not that all ships have to be righted that way, but while moving in formation / as part of an armada it's the gentleman's agreement kind of thing [Answer] **Space is locally nearly flat** The solar system is more or less flat. The galaxy is more-or-less a flat disk. Therefore space is more-or less-flat. When a fleet of spacecraft set out they are constrained to a locally flat formation whether they want it or not. You may think this is an unsustainable view but no-one could believe that the speed of light was constant regardless of the motion of the viewer. Even Einstein didn't believe in some of the conclusions of quantum mechanics. [Answer] If the formations are incorrectly visualised, what would the real formations be? Dangerous ionised radiation would need a comet-informed allignment, with an ionised-radiation-shield pointing to the nearest star. Behind this umbrella would be a 'tower' of modules. Imagine an umbrella open, with the tower being the handle, but made from perhaps 3 radio mast or construction crane style triangulated members. Easy gravity comes from acceleration and deceleration, presuming you have the energy management to do it. People would be in a manned module mounted in a gimbal at a safe level in the tower, with a periodic floor to ceiling inversion of the manned module as the tower shifts from steady acceleration to steady deceleration, or vice versa. There would be a few moments of weightlessness as the module inverts, defining floor and ceiling for the manned module. A formation would have individual 'tower' ships all pointing down radials toward the centre of the nearest star, whilst the fleet would have a line of advance as they choose. The advance along that heading would be in periods of acceleration and deceleration. The module 'turnarounds' would likely be staged, with ships covering for each other as they each take their turn. The fleet would become more closely positioned along the line of advance as they each make the deceleration inversion, and more sparsely positioned as they each make the acceleration inversion. [Answer] # Weapon Physics Space has no terrain, given the infinitesimal scale of planets and asteroids. Therefore, any combat formation would be determined by the physics of the weaponry being used above all else. Ships would be spaced close enough that they can provide effective supporting fire, but far enough that they won't all be wiped out by one area-of-effect weapon. This optimal distance will be the same for the whole fleet (or across all ships of a type). Therefore, if you want to have your ships operate to the fullest they need to be packed in at that range, hence: a formation. [Answer] To have a decent orientation you need to have two factors that each orient the ship in one dimension. On Earth we have 'down' that gives us one direction. And 'forward' gives us another. In the case of rockets, down and forward are in the same axis, and so one orientation is immaterial. Suppose that you have a ship drive that is truly anti-gravity. You may need to orient the ship to get the best efficiency. Piper's novels talk about the Abbot "Lift and Drive" for his reactionless flying vehicles. The lift component deals with gravity, the drive component moves the vehicle forward. Suppose that your ships are not cylindrical symmetrical. You have internal missile decks with missile tubes that run across the width. (Weber's Honorverse books) You want that broadside pointing at the enemy. In WWII some pains were taken to arrange bombers in formations that give mutual covering fire defence against fighters. (After I think, further studies showed that it wasn't effective...) Suppose that a fleet has a communication advantage when in some orientation. E.g. you have an array of comm lasers that form a grid. Or you are using the entire fleet as a phased array radar interferometer to get precise fixes on the enemy location. Or that same phased array allows the entire energy weapon output to be delivered in perfect unison to a single enemy target. Ships in space have to deal with heat, balancing what naturally radiates into the near absolute zero of space, and internal energy and solar heating. Make your ships like flat bricks, with anisotropic (beamed) radiation surfaces. Orient the flat surfaces toward each other -- stay warm. Orient so that all the flat surfaces can radiate to space -- cool off. (This one is a bit thin. I suspect that the energy use in anything that moves to another star in reasonable time is going to overwhelm radiation processes at human livable temps.) [Answer] I noticed that SCIFI movies always show it as a default, not giving it a second thought, as if this is normal. For a space-faring society, the first step towards space travel is putting satellites and stations in orbit. In this "relatively" small space, all nations on the same planet, having space-ports and space planes, may employ the same orientation for simpler flight-control procedures, docking, and setting direction. Normally, this direction is set-up using the north/south pole reference. Just as with airports, space-ports are where space ships are closest to each other, and flight-control (akin to airport flight-control tower) is a MUST. The same goes to expanding the flight control to other planets of the same solar system. On the other hand, alien societies may have a different orientation. Still, that is not a problem. A ship entering the space of another control system may pick-up the signal that provides the "where and when" to enter into the orbital plane and the correct orientation. Still, there should be some agreed protocols for that to work, but once it has been done, it's piece of cake. ]

[Question] [ Most of the religions I see GMs make (& even myself) are basically just rehashed Greek pantheon-esque religions. Several gods, each one governing a specific thing, sometimes different regions have different gods governing them. They are all still (pretty much) the same style of religion though. How do I create a unique religion? Some GMs have themselves as one god, & that is fun to experiment with, but it is also very modern-catholic with monotheistic religion & all that. Sometimes godless religions are interesting but I'm not sure how to go about those either. (This is not strictly for RPGs btw, it's just where I have most experience.) [Answer] 1. Mythology is not religion. Mythology and religion are two very different things. Funny thing is, the ancient Greek *mythology* we all know and love was not the actual ancient Greek *religion*. For an introduction to the subject, I recommend: * [E. R. Dodds](https://en.wikipedia.org/wiki/E._R._Dodds), [*The Greeks and the Irrational*](https://archive.org/details/E.R.DoddsTheGreeksAndTheIrrational/) (1962). (This is a foundational book; highly recommended.) (Link goes to a free copy at Archive.org. You can of course also find the book on Amazon.) * [Paul Veyne](https://en.wikipedia.org/wiki/Paul_Veyne)'s *Les Grecs ont-ils cru à leurs mythes?* (1983), translated into English by Paula Wissing as [*Did the Greeks Believe in Their Myths?*](https://rads.stackoverflow.com/amzn/click/com/0226854345) (1988). (Link goes to Amazon.)To get a quick taste of the *actual* Greek religion, read the Wikipedia article of the [Orphic mysteries](https://en.wikipedia.org/wiki/Orphism_(religion)), the [Panathenaic festival](https://en.wikipedia.org/wiki/Panathenaea), or the [temples at Delphi](https://en.wikipedia.org/wiki/Delphi). For a simple example, consider that the Hebrew, Christian and Islamic religions share more or less the same mythology. But the religions themselves are quite different, aren't they? Not to mention the striking differences between the mainstream variants of Christianity and the modern interpretations prevalent in the USA. 2. No, the Greek mythology does not feature *"several gods, each one governing a specific thing"*. It features *countless* gods, the vast majority of whom do not govern anything. They just *are*. The real ancient Greek religion is not even close to the nice ordered idea of a handful of gods with well-defined responsibilities. I understand where this idea comes from. Schools teach that Ares was the god of war, Poseidon was the god of the sea, and Aphrodite the goddess of love. Sort of correct, albeit extremely reductionist. But what about Athena, or Apollo? What did they govern? Not to mention the zillion other deities, such as [Tethys](https://en.wikipedia.org/wiki/Tethys_(mythology)), [Thetis](https://en.wikipedia.org/wiki/Thetis) (who married a mortal man and gave birth to Achilles), and, perhaps most importantly, Hercules (who was born a mortal man and became a god by his works and by the good will of his divine father)? 3. There are *other* ancient religions which are well documented. Consider the Roman religion. We know all sorts of details about it, and they are easy to find in this day of universal access to knowledge. A good starting book is Franz Altheim's [*History of Roman Religion*](https://archive.org/details/altheim-franz.-a-history-of-roman-religion-1938/) (1938). (The link goes to a free copy at Archive.org.) Yes, the Romans, in their arts, their poetry and fiction, re-used the Greek mythology. They did not adopt or practice the Greek *religion*. They continued to practice their own, very different religion. This only reinforces point 1 above, that mythology and religion are very different things. The Roman religion was about as different from the Greek religion as they could be while remaining under the general idea of polytheism. The most important difference is that the great majority Roman deities were purely abstract entities, who did not look like mortal people, did not mingle with mortal people, and did not have adventures with mortal people. A handful of Roman gods, such as Apollo or Bacchus, are indeed literally the same as the corresponding Greek gods; the Romans borrowed them fully formed. A second handful or Roman gods, such as Jupiter and Aurora, are reflexes of the same ancestral Indo-European gods as the corresponding Greek gods. But the great majority of Roman gods are fundamentally and essentially different from the Greek gods. This includes major gods which were assigned Greek equivalents for purely artistic purposes: Mars, whose association with war is just one of his many facets, is profoundly different from Ares; Venus is only superficially similar to Aphrodite; and Greek Athena was interpreted as Roman Minerva only because they are both very powerful, very wise, and female. Even their names attest that they are fundamentally different deities. The names of Minerva and Venus are Indo-European (from *\*menos* "thought" and *\*wenh₁os* "desire"), while the names of Athena and Aphrodite are alien; Athena is probably a deity of the peoples who lived in Greece before the Greeks came, and the name of Aphrodite is likely of Semitic origin. The Greek religion does not have anything similar to the entire very important house-and-family section of the Roman religion -- the [Penates](https://en.wikipedia.org/wiki/Di_Penates), the [Lares Familiares](https://en.wikipedia.org/wiki/Lares_Familiares), the [Manes](https://en.wikipedia.org/wiki/Manes). The Roman religion is the archetype of *"very many gods, each one governing a specific thing"*. Consider [how many deities were involved with making a baby](https://en.wikipedia.org/wiki/List_of_Roman_birth_and_childhood_deities) and raising them; here is a partial list, roughly in chronological order from marriage through conception, pregancy, birth and early development: Jugatinus, Cinxia, Subigus, Prema, Inuus, Janus, Consevius, Liber Pater, Mena, Fluonia, Alemona, Vitumnus, Sentinus, Egeria, Postverta, Diespiter, Lucina, Vagitanus, Levana, Statina, Intercidona, Pilumnus, Deverra, Juno, Hercules, Rumina, Nundina, Potina, Edusa, Ossipago, Carna, Cunina, Cuba, Paventia, Peta, Agenoria, Adeona, Interduca, Catius Pater, Farinus, Fabulinus, Locutius, Mens, Volumnus, Numeria, Camena. (Most of their names are indicating their functions. You may want to test your Latin to guess what each of them was supposed to do, without going to Wikipedia.) Or consider the ancient Egyptian religion. It is also very well documented; but, since it doesn't interest me in the least, I won't comment on it. Or the [Babylonian religion](https://en.wikipedia.org/wiki/Babylonian_religion). Or the ancient [Vedic religion](https://en.wikipedia.org/wiki/Historical_Vedic_religion) of ancient India; and of course its successor, the [Hindu religion](https://en.wikipedia.org/wiki/Vedic_religion). None of them is similar to the ancient Greek religion, and they feature very un-Greek mythologies. 4. An easy path towards making up gods and goddesses is to actually learn about the ancient gods and goddesses. I promise you that you will surprise many of your readers or players. The ancient gods and goddesses were complex characters, with complex histories and complicated cults. Very far from the elementary school introduction "Venus is the goddess of love". Speaking of Venus. Most people think that they know that Venus is Roman name of Aphrodite and that's about it. The reality is that the Romans used the mythology of Aphrodite *in the arts, in fiction and poetry*, because, again, Roman deities were abstract entities and they mostly did not have any physical form or any mythology to speak of. The [real Roman Venus](https://en.wikipedia.org/wiki/Venus_(mythology)) was indeed a goddes of (physical) love and sexual desire; but she was also, surprise, the goddess of prosperity, success in enterprise, and victory. She was the goddess of nature's generative force. There is a temple of Venus Libitina, the goddess of funerals. The Romans prayed to her to intercede with Jupiter on their behalf. 5. Alternatively, you may want to consider a completely unstructured religion, such as what pre-modern China used to practice. Archive.org has J. J. M. Groot's *The religious system of China* (in six volumes!). [Look for it.](https://archive.org/search.php?query=creator%3A%22Groot%2C+J.+J.+M.+de+(Jan+Jakob+Maria)%2C+1854-1921%22). 6. In general, you may proceed with absolute confidence that if you spend a few days on this you will find one or two sufficiently attractive real-world religions, which can be slightly touched up or mashed up to create a sufficiently surprising religon for your story or game. As a brooding and impractical prince of Denmark once said, *"there are more things in heaven and earth than are dreamt of in philosophy"*. [Answer] **Brahman** [](https://i.stack.imgur.com/q8O3ql.jpg) You have left out the third kind of religion. Many eastern Religions have a nonpersonified Godhead. The fundamental nature of reality is not a big man in the sky. It is the arrangement of the world into tiers, with the lower teirs being closer to nonliving matter, and the upper ones being closer to a state of nirvannah. There is also a cycle of reincarnation and means to move upwards baked into the system. Some such religions contain beings which are also called gods. But these are just creatures higher on the spiritual ladder. They are not creator deities and do not embody aspects of reality. Arguably the standard D&D cosmos is already this type of setting. The nonpersonified force contains the "River of Souls" [](https://i.stack.imgur.com/mJZbB.jpg) which governs how souls are generated and where they go after their mortal bodies die. The "gods" are simply souls that have attracted enough followers that they become divine. They are not creators and will fade from existence if they are forgotten. This "rule of faith" is also part of the nonpersonified force. [Answer] # Variation is Godliness: There are so many ways to mix up faith that it is, actually kind of funny: * **Mesoamerica**: There have been some good alternatives listed here for alternate pantheons, but Mayan and Aztec religious traditions are messy, complex, and full of great stories waiting for someone to follow up and bring them to life. * **Gods based on nature**: A traditional faith might be based on nature. So gods might be gods of trees, plants, the sea, and animals. Or all gods might be represented by a specific animal. * **Eldritch gods**: The gods are REALLY alien, with motives we don't really get. So priests and followers don't worship so much as manipulate gods ritually for protection or power. Why does the sacrifice of 144 baby toes revive a dead person to become a zombie? We have no clue, but Zeb-Nusushush does it. Period. * **Gods based on assumed characteristics of things**: So the god Yellow is angry but is associated with sunlight. The god of black is calm but also of death. White is associated with both winter and the moon - what does that say about a god? [Answer] Gods of places. Instead of gods having spheres, they are gods of cities, or regions. They may pick up a few associations--the god of a merchant city is connected to selling--but a merchant from a mining town honors and relies on the mining town god. [Answer] One option is to have various "gods of", but instead of making them gods of an activity, profession, region or race, get creative with what's being divvied up between them. For example, take the Myers-Briggs personality test. Introvert/Extrovert, Thinking/Feeling, Sensing/Intuition, and Judging/Perceiving. From that, you can get * The god of solitude * The god of companionship * The god of reason * The god of passion * The god of focus * The god of creativity * The god of order * The god of opportunity These also don't really need to be beings. You could make those aspects of the mind the figureheads of the religion. People could believe that the concept of companionship itself is woven into the fabric of reality in a meaningful and divine way. [Answer] It's probably necessary to understand what a god/goddess is, if you want to mix it up a little and come up with a unique deity/pantheon/religion. Most of the details are lost to prehistory, unfortunately. But we can reconstruct quite a bit about how the concept of a god must have emerged. It goes a little something like this: Humans believe in spirits. These spirits are intelligent and usually (but not always) intangible. Other humans clearly have spirits, and so too do non-human animals. But then, so does the wind, or the moon. If you see a dust devil blowing around, clearly that's a spirit, and it will be tangible for a short time, but then return to being intangible. These other spirits, the intangible ones, they are like humans also in that they're neither good nor evil, at least no more than any other human would be. Sometimes they will help, sometimes hinder, sometimes love and sometimes hate. And they might change their minds! You've hunted for many seasons always having great fortune, but then the spirits abandon you and your family is starving. One might start to wonder, were he in that situation, just what he did to offend those spirits. Humans definitely tried to befriend them, or, if that seemed impossible, to at least avoid offending them. This is somewhere around where we'd start calling this animism. As some humans specialized in "spirit relationships" we might even get something resembling shamanism too. But at least so far, none of these spirits are gods! For that, we need a bit more development. You see, over time, a tribe or a people here or there might come to give names to these spirits, and to favor some spirits over others. Great-grandfather always said that spirit A seemed to be friendly and would help when it could, and spirit B was always being a jackass. Scaring away the game, snuffing out the fire in the cold winter nights. Now, up until this point, spirits were more or less equal (at least in the way that humans are more or less equal). Sure some were more powerful than others like some humans are stronger or faster than others, some more skillful, just as some humans are more skillful. But as spirits start being named, it is possible for stories to attach to them. And for stories to accumulate. From that point forward, human psychology kicks in. There might be thousands of spirits (millions, surely, if they could even comprehend that number), but if you only know the names of a dozen spirits, then those will eventually become the most powerful spirits to your great grandchildren, simply because they will accumulate stories where the anonymous spirits can't. And while offending spirits was always a risky business, you definitely don't want to piss off Spirit X, who your family has told many tales about for many generations, where that unnamed spirit that lives out in the swamp and has one story (if you can even be sure it's about him) isn't some sort of world-ending, existential threat... even if you insult him. We might call this the "veneration phase". Spirits so powerful as that, you have to practice a bit of diplomacy. You need to be formal with them. They should be greeted. Invited in. Gifts might be given, at least when appropriate. When insult if (accidentally, never intentionally) given, proper apologies must be made. There is more though, at this point. Those stories? It's not just about them existing in the same world as you do (or, depending on the mythology, in another slightly adjacent world)! These spirits were, in some cases, present at the birth of the world. They were involved in it. They witnessed it. And why not? A human might die, but surely an intangible spirit can hardly be harmed. And if they will persist into the far future, would they not also have already persisted starting some time in the distant past? They're just a few developments away from potentially having *created* the world. Soon, the diplomacy, the greetings and invitations, the apologies and the gifts, they will become rituals and offerings (even sacrifices). They'll soon be (lowercase g) gods. And, they'll slowly become more human-life in appearance. While even Coyote or Rabbit or whomever could always walk among men and appear to be a man (if he chose), that's merely an affectation. But some of these spirits/gods will soon be looking like men even when they're not doing it for any particular purpose. The transformation won't be total, necessarily, especially early on. Some human-like gods will retain animal-like features even as long as the religion itself survives. In societies which are growing more complex (like the Greeks who, by now, are building some rather large cities), some curiosities occur. They are having quite a bit more contact with foreign societies. Contact that's not just hostile, communication-less warfare. They come to recognize that while some gods of foreigners must be the same ones they know and love, those foreigners definitely don't use the same names as they do (besides, we all know these gods like to keep a low profile and sometimes use a variety of names!). So they start trying to match up foreign gods to their own. Sometimes the matches don't make alot of sense to us, but surely he can't be the god of the ocean to people who live 500 miles away from an ocean, maybe he likes to dabble with horses that far inland. More so, we're starting to see the emergence of subcultures... cities might have potters and carpenters and so forth. And as their subcultures come to favor particular gods, those gods will of course favor those subcultures. We can now have someone who is the god of soldiers, or the goddess of milkmaids. (And if that sounds quite a bit like Catholic saints to you, then you're starting to get it.) The rituals have grown more numerous, longer, more complicated. We're definitely at the point where you don't dare deal with them directly yourself, it's far too important to trust to a non-specialist. Priesthoods have emerged sometime in the recent past. Like any profession, one of the first rules is to make their profession indispensable. So the rituals are only going to grow more complicated still, and the risks of performing them poorly will only grow more dangerous. The next developments doesn't always occur. One of those is monotheism. It requires that a people grow so attached to their god that when forced to leave their homeland (and god) behind, they refuse to allow that to happen. Gods, like the spirits they once were, are mostly intangible, so why is geography relevant? If you can't touch or see something, where is it exactly? You're only one abstraction away from him being "everywhere at once and nowhere". Now, of course, there are still other gods. But this new portable version of a god can help your people survive enslavement, long stretches in a desert searching for a homeland, and a host of other psychologically debilitating circumstances. And the best part? If you're one of the first to have a portable god, then your god most be more special than most. He (uppercase H) might be the one true god. Boom, monotheism. Other gods will hang around, but eventually they will become spirits again, lesser evil spirits perhaps. You religion might have trouble reconciling those with the new monotheistic universe. And you might have to try really hard to repress your memories of the other gods in your pantheon too. The other development isn't entirely compatible with monotheism. Call it duotheism. You live in a land of barbaric wars ravaging through every few generations. You have enough technology, and enough population density, that these are awe-inducing (the old definition of awe, the one that is closer to "fear of god" than "really really cool). There are enemies, and there are good guys. And so it must be with spirits too. Turns out, these spirits have been engaged in cosmic warfare since the beginning of eternity. And only one side can win. And hopefully it will be the good ones. There is one spirit above all on each side, and these are truly Gods. Uppercase G gods. But don't worship the bad one lest you mark yourself an enemy of the universe itself, and eventually smited for that. What can we take away from all of this though? 1. That instead of gods and goddesses being some distinct category of being, they exist on a wide spectrum of spirits. 2. That these spirits, lesser and greater are more defined by their relationships with people than, than any demonstrated power or faculty of their own. 3. That they accumulate patronage much the same way the wealthy do, rather than being some incarnation of the concept. The god of thieves wasn't born of some Platonic ideal of thievery, he just helped one out one time, and now he's kind of expected to do so all the time. So, to make gods and goddesses different, you're going to need to interrupt some of these processes. If you think those interruptions make good backgrounds for the story you're working on, be sure to include that stuff. But if it distracts from what you're doing, jot down some notes and skip that. Perhaps these gods do not become more humanlike, retaining animalistic visage. Or, for whatever reason, instead of their being millions, it truly seems like there are only 5, or 3, or 111. Monotheism is easily skipped (indeed, it might only have been invented twice in the real world, and the other example may not have developed in the way that I outline that it should, no one's certain!). Duotheism is easily skipped (only one extant example, though there are some elements of it in Christianity, likely borrowed from that example). Gods might not become patrons of any one thing. They might remain more tangible. They might not develop names. People might be unwilling to accept the existence of gods their own tribe doesn't vouch for. Any of these mechanisms can help you to develop ideas for what those gods would be like, and they will tend to be quite unlike those described in history of our own planet. You can go out of your way and develop details for those, or just say "X didn't happen" and "Y happened to a far smaller degree" without bothering to explain. And the best part? This works whether your gods are real, or just the religious delusions of a primitive people. [Answer] In the last century, many thousands of 'new religious movements' (aka cults) have appeared all over the world. These are mostly small and short-lived but some have membership in the millions and have persisted for generations. All of these religious movements are based, in some way, around the question you are asking: "how do we create a new thing that is different from this old thing?" Of course, they're cults, so they're trying to claim that their new idea or new way of thinking is literally true rather than fictional. However, many NRMs involve a fusion of different cultures and ideas. For example, the blend of Islam and Buddhism. These are two entirely disparate ideas where one is monotheistic and the other is non-dualistic. You may ask, "how could anyone combine those two ideas? They're too different." Well, a cult is like a universal translator between them. You can invent pretty much any word-salad justification or convoluted sophistry to explain any relationship between P and Q. For worldbuilding, this can be a fun creative exercise (so long as you don't start believing your ideas are literally true): e.g., find one interesting part of one religion and one interesting part of another and spend a few hours writing about what would need to exist in order for them to be connected / mean the same thing / exist in the same religious framework. For example I might want to write about a culture where something like the Buddhist concept of Prajna (wisdom) arises as a consequence of, say, Catholic mass. There's no right answer, I just made it up, but the point is that someone could make an argument that they are related. You could argue that almost any two things are related. What world would be required for it to be true? (There are issues about cultural appropriation here, which I could write pages about, and I'm not suggesting just stealing ideas from other religions at random. But using them as a basis for creating new ideas is not a bad thing when it's used as a personal exercise rather than an attempt at exploiting that culture, in my opinion. Others may disagree but in any case that's an off-topic digression.) [Answer] To understand religions - and superstitions - it may help to understand how they arise. Put quite simply, they begin as lies to children. Imagine that you're a parent with kids. You have things to do, but the kids are being kids, and are asking you questions to which you don't have the answer, like "Where did the world come from?", so, when they won't accept "I don't know", you toss them an answer off the top of your head. You make something up, and that shuts them up for a while, during which time they consider it and work it into their view of the world. Then they come back and ask more questions about the flippant lie that you told, and you make something else up. And so-on and so-on... Now, maybe you're a better story-teller than the other parents. Maybe the other parents couldn't think of anything other than "I don't know", but they heard another parent telling a lie to *their* kids. Maybe they believed it themselves, maybe they didn't, but your lie shuts up their kids too. The kids *believe* your lie,and it becomes part of their worldview, because that's what older people in their community are there for: to teach them things that they don't know. Mostly it's practical stuff, like how to catch fish/kill deer/plant crops/whatever, but kids don't discriminate between useful knowledge and unfalsifiable lies. Now imagine that you pass away, and then imagine that you are one of the kids to whom you told your lies... one of the more imaginative ones. You have this view of the world that you learned from an elder, and remember it better than the other kids did, and you tell it to the new kids in the community. When they ask a question for which you don't have an answer, you make something up that fits with what you know. Give it a few generations of this, and if you want to know about all this made-up stuff, you'd need to go to a special school... and now you have clergy. Of course, not all lies to children are attempting to explain the abstract. Some lies have a definite aim. Take, for example, the myth that cats get into babies cribs and suck away the baby's breath. In actuality, a cat would just be looking for a warm place to sleep, and might accidentally smother a baby who wasn't old and strong enough to move away. Maybe it happened to a mother in your community, and she did the human thing and ascribed evil motive to the cat where none existed, but the story did the trick and made other mothers keep cats away from young babies. If enough other tales of evil are ascribed to cats, sooner or later, people are hunting and torturing cats to death, and then, when there aren't enough cats to control the rats, your community is struck by the [black death](https://en.wikipedia.org/wiki/Black_Death). Should have been nicer to the cats, perhaps? There are any number of other cautionary lies to children that had the aim to keep kids away from danger... but they filled the kids world with imaginary fears,which they passed on to their own kids, perhaps not understanding why they were told the story. The story gets passed down through the generations, but the reason doesn't. Maybe a generations-old story still performs its intended function, maybe it doesn't... but it's now superstition. Now, take a story world... perhaps a ttrpg world. It's a short step for all these lies upon lies told to children to be made into a real part of the world that's being described. In some worlds, especially D&D worlds, it seems that there are no myths... everything that the world-builder describes is real somewhere. Perhaps the young players get upset if they're told about something that doesn't exist, and they've spent time looking for it. So... knowing how myths,legends, religions and superstitions arise, you have a means by which these can be created for your world. Just remember that it's an iterative process. Make something up to answer a question. Make something else up to answer a deeper question. Keep making stuff up as required until you're satisfied with the results. Occasionally, you may want to toss something away because it doesn't fit any more... and that's okay. Myths, legends, religions and superstitions are full of places where someone decided that something no longer fit into the story, and it was removed... but left behind bits and pieces in related stories, now without any apparent explanation. [Answer] **Look at Non Indo-European Religions and Non Mediterranean Religions** Greek mythology is going to share features with those of other Indo-European cultures (Pretty much all of Europe save for the Basque, Magyars, and Finns; alongside with the Iranian and North Indian cultures). So to properly avoid any sub textual references to Greek deities simply choose religions that are not a part of the Indo-European cultural group or from the Mediterranean region. Consider basing your religion off of Tengriism; a living Central Asian. Consider researching the religions of sub Saharan Africa or the Americas or Oceania [Answer] # Don't just go meta - go Zoroastrian meta Your characters have a sense that there is a world beyond their own. They go throughout their lives, but their actions are influenced by [Fravashi](https://en.wikipedia.org/wiki/Fravashi) (players), who have heeded the call of [Ahura Mazda](https://en.wikipedia.org/wiki/Ahura_Mazda) (the GM). The Fravashi even get to see their score, called an *urvan*, the fourth day after the characters die. The religion of the characters will involve prayers made to the Fravashi and Ahura Mazda. Some of these will be invocations aimed to produce the manifestation of materials from the players' own world so that the characters can learn the Zoroastrian faith and convince their players (Fravashi) to start following the religion. The players may refuse, and the characters could become convinced that some of them are really in league with Angra Mainyu. They may ask the players to ask themselves, are they really players at all or are they just hypothetical entities in an unplayed game posited in a StackExchange answer to a question that, alas, looks like it is about to be descended on by minions of Mainyu who override all our great conversations. Can the players appeal to *their* Fravashi to avoid that fate? There is a parallel branch of the religion that phrases all these terms in relation to a "Matrix", but it appeals to a much more limited group of mages I think. [Answer] ## To Build Your Own Mythos, Start With What You Know There are two jumping off points from our world of the mundane into myth : * *mind* : also called *psyche* to Freud, *animus* to the classic scholar, or *soul* * *mood* : *team spirit*, *emotion*, or just plain *spirit*. **There are some big decisions you make regarding these two starting points that can take you into some very different directions** * Regarding the "mind" or "soul", is it something unique and eternal, or just part of the body? This is a question with large ramifications + if the answer is "no", - What does "resurrect", "raise dead" or equivalent miracles do? Do they not exist in your mythos? - What, then, are the "gods"? Just powerful players on the stage of life? + If the answer is "yes", you have a lot of minds doing something after death. What? - They could be sleeping until awakened by some powerful magic (like a deities miracle). - They could be reborn after some time (which would imply an upper limit, and maybe not even a long one, on "resurrect"). - They could be hanging out with similar-minded peers, just out of sight of most mortals. * What is "spirit"? Is something external, an invisible animal or wind that touches the soul without any physicality? When we say we've been "taken captive by a mood" or need to "get a monkey off our backs" do those words have literal truth? + If yes, you have the possibility of animal spirits. - Could some of these spiritual animals be of near human, or greater than human intelligence? * If yes, you have the "genie", "djinn", "ifrit", "geniuses", "angels" and "demons" of some mythologies. - Do these spiritual animals have an ecosystem of their own that they inhabit? * If no, everyone is dwelling on the players physical world, asleep or awake, invisible or visible. * If yes, the how many different spiritual worlds exist? + One : like the astral plane, there is one world that the spirits inhabit, just a little offset from the main one of your story. + More than one : there could be realms full of story (like Neverland). There could exist realms in which the gods preside over courts of their spiritual and soul servants and make plans regarding the living (hells and heavens). + If no, what is mood? - Some happy accident? - Some aura of the divine? For example, does "the power of love" mean something? - Some power that transcends the divine? Same example, does "the power of love" put even the mightiest of deities in their place? * In some mythologies there exist certain laws that are immutable, maybe set by the very highest of gods, or just always been there. **Option:** A great filter may be in place, applying some absolute standard of behavior (in your universe). Unambiguously establishing what was "good" behavior, and separating your souls into buckets because of it. Better souls may reincarnate into better next-lives, or souls may align with the god(s) most like them "noble self-sacrificing altruists", or "greedy bottom feeders". **Option:** If souls are eternal and spirits are separate, you might have a economy trying to lock down the living's final destination by trying to get the living to "sell their souls", literally selling their living mind (and maybe their afterlife) as a long-term service contract. **Option:** If spirits and souls exist, and report to a deity, the deity may posses turf in the real world. Companies of soldier souls/spirits may be encamped within the borders, protecting the city or the nation from outside harm. For immortal creatures such as these, they may be limited to just picking up their colleagues and carrying them across the border. However, it may have literal meaning for a city or army to "lose its spirit" when battling another army -- the battle may have been conducted, first, between the armies of two squaring off deities, and one army has been routed. ## What, Then, Are The Gods Now that you've identified the answer to life's bigger mysteries, how do these beings called "gods" by the living relate to those higher truths? The answer could be nuanced. Some gods may be "lesser" than others. * There could be truly omnipotent, omniscient deities. In this case, everything is going according to their plan, or at least is happening with their consent. * The gods could be kings and queens with private inviolable spaces ("heavens" or "hells") where spirits and souls - working still for the gods - are actively put to work achieving the deities goals among the living (and maybe in the broader cosmos). This means a lot : the god / goddess has *armies* that can be put to work, when needed. * The god could be powerful monsters, or very powerful heros. They may choose to pick favorites from the people - help some out, or make life more difficult for others. + Worse than monsters, the gods could be parasites depending on the living (and unliving, if they exist in your world) for something, and giving little or nothing back. * The gods could be nigh-nobodies : political figures - mortal kings, and queens, who merely want the devotion from their people. ## What Do The People Mean to the Gods? Knowing everything you've chosen for your absolute truths above, what does this mean to the prayers of mortals for their deities favor? Are they heard? Ignored? Meticulously answered as often as possible, considering the well-being of all believers? **Option:** You might think that it would be pure chaos for every prayer to be answered, but remember that an intelligent creature can answer "no". * Petitioner : may I have the stuff of my neighbor, please? * Deity : no. Even atheism could exist in this scenario - the Petitioner may choose to reject a god(s) that won't give him what he wants. The reasons can be even more legitimate, like, why has the deity allowed tragedy to happen generally in this world, or some terrible atrocity in particular. ## Where Do Clerics Fit In? You've answered those awesome fundamentals, first, then reconciled what that makes the gods. Now (especially if you have a fantasy setting including them), what about the clerics? If souls exist, the relationship between a cleric and a god may be as simple as a contract for the cleric's soul. Or, some good deities may refuse to accept that and simply require faithful, disciplined service. A powerful, but limited, hero/god in a world of no spirits or souls may give a follower a magic token (a cellphone) that helps the cleric keep in touch while the god journeys the material plane. Or a monster god may tear the cleric apart and rebuild the former human into something not-quite human. Or, a powerful but limited hero/god may just add the cleric's name to an allow-calls-from list. The only interaction between cleric and god may be at the scheduled check-ins. In this case, hitting the appointed prayer time(s) is even more important to the cleric than it might be for others. **Who performs miracles?** Who actually grants a miracle that a cleric asks for. It could be : * The deity personally through his/her far reaching power * A soul or spirit, working for the god, using powers of their own * The cleric, tapping some otherwise unknowable power of their own soul/spirit (a capability which may continue and even flower after life). A monster deity may put a cleric through some sort of transformation endowing the cleric with this power. ## What About the Church? The aims of an very-powerful or nearly-all-powerful deity and a regional Baron + Count + Duke + Soverign are rarely going to align. Very likely, these four living people are rarely in alignment with one another. These well-placed individuals will be the ones (likely) paying the expense of the deities outreach centers (churches) at the village, county, province, and nation levels. The Sovereign or local noble will insist, in return for his or her day-to-day charity in the gods dealings, some right to name who runs these outreach centers. A noble would be likely against selecting for those roles people who have been somehow bound to the deity, preferring instead men and women with loose ties to their gods and strong loyalty to their noble patron. How do the churches relate to clerics? * There may be True Clerics (who have sworn themselves in some way to the deity) operating at various levels along the church hierarchy, or roaming as itinerants. * The deity may tear down churches operating in the gods name without his followers, creating a shortage in religious services (not a church in every town, or maybe not even in every county or state). + Traveling preachers may be sent into the underserved countryside at some frequency (for example: spring to bless crops and conduct weddings, and again in winter to properly bury the dead). ## How Do the Gods Relate to Each Other? Usually the question that gets the most attention from people, but probably the least impactful in how your mythos runs is : how do the gods relate to one another? They can be colleagues who work together, but share no other common bond. They can be family. They can not be aware of one another at all (or by reputation alone) - especially if you have very many kind-of weak gods who are just very potent players or monsters. [Answer] Skip the gods, and stick with just magic. Many that believe in Reincarnation believe in "Karma", a form of magic that causes you to be reincarnated either higher or lower; but there is no personified "God". Witchcraft can also be a form of religious practice without personified good or evil; there is just magic to be learned. You see this in the modern "Attraction" stuff, you do certain things to "attract" what you want, and it will magically appear. Of course confirmation bias plays a big role in this. One can believe in a magical substance of "good" and substance of "evil" that concentrates into people, making them better or worse, along with rituals to purify people and cast evil out. Also called "spirits", but same idea. The same reincarnation people are a subset of those that believe in souls and ghosts without believing in any God. The reincarnationists just believe that the soul is reborn; while others may not believe that, or may believe the soul cannot "move on" to a new life until it sees issued resolved in this one. That kind of thing is represented in the "I see dead people" movie, The Sixth Sense. You can do a lot in rituals, celebrations and such without ANY gods, but with plenty of Magic as a kind of natural force in the world. [Answer] **There Are No Wrong Answers, and There are no Right Ones. Use Them All** In our own world, there is a great diversity of religions, almost all of which have some central figure at the foundation of their collection of holy beings. What you said about monotheism is actually wrong, it is not a very modern catholic thing as it is the core of other Abrahamic religions and countless tribal religions before european contact. But whatever the case, your religions will be diverse, so if you simply want diversity, you could just copy and past other religions, but that is a boring answer, isn't it? Now, when it comes to religions, religions are ultimately about worship. "god" when defined primarily by the role of the concept in religion, is a being worthy of worship; so, in your own worldbuilding when you are asking "who are the gods" you are asking yourself who these people consider worthy of worship. Some may not think about worship. Others may limit their worship to people living on the same plane of existence as them. Some may believe there is only one God worthy of worship, and others will worship many gods. Some may even go to worship themselves. If you want to know who those gods should be, a quick look at the worlds pantheons should tell you that people can think *anything* can be worshipped, and your fictional humans will be no different. Sure, they may not worship page 22 of nancy's cookbook, but they may be captivated by the beauty of the mathematical realm and see divinity there (like pythagoras) or believe that everything is god (pantheism) or consider all the stars in the sky and the sun and whatever moons and planets you see to be a pantheon of gods giving light to the world, and consider only those literal objects to be distinct personal gods, and so on and so forth. There should be religions of every type in your world, and each of them will produce their own unique cultures due to their beliefs about divinity, history, and morality, and how closely they actually hold to those beliefs. Also, you should consider the fact that Aristotle and other philosphers came to the conclusion that there was only one God from philosophy alone, and they did so not on the basis of any feature present on earth, but on the fundamental nature of existence. Even if you disagree that these arguments are true, you should note that those arguments are made, and a classically theistic religion, no matter how small or how short lived it is, will almost certainly exist on your world at some point; though they may not have similar claims about revelation that christianity, judaism, and islam do. **Start with the Truth, and Lie from There** Basically, lets say you don't want a religious landscape that parallels the religious landscape of earth, but something completely different. Well, one of the things you could do is start with a completely different foundational truth which all the religions of the world are based on. I know I sound like I am inferring that all the religions of our world are based on some foundational truth, which I am, but I do not feel it to be a good time to open that can of worms. Instead I will merely point out to you that when it comes to religions around the world whose origin story is well within the historical record, we are able to see how these religions, like mormonism, christianity, islam, sikhism, and so on are based on the religions of the region they came from, with certain alterations, and we would expect this same process to have occurred throughout all the parts of history we can't see until we came to some first religion, since religion couldn't exist forever you know, as humans have a beginning. But, that is not the point, the way you should apply religious development to your world is different. For this section, I intend to point to Brandon Sanderson's worldbuilding. The religions of scadrial and roshar for example have religions which have certain common elements (scadrial: dualism, martyr god, hero of ages, preserving something; Roshar: ten heralds, almighty (or similar concept), desolations, old magic (in the west), lost radiants). The common elements of each of these religions are based on the stories which were at the very foundation of all of these societies, though all of these elements are corrupted. Even seemingly random pieces of religious thought, like some people on Roshar believing stones are holy gods, are actually referencing some ancient event that actually happened at the very foundation of the societies which believe these things. What I mean by "start from the truth and lie from there" is to figure out those events at the very beginning of your worlds history that *actually happened*, a story of origins, and figure out how those events were misinterpreted at the start, and how the understanding continued to corrupt over time. Their perception of God or gods will also be affected by the beings who are clearly present at the event (or whose presence was inferred). **But Remember the Lies of Immortals** However, one important thing to remember about religion in a fantasy setting, one thing that doesn't apply to the real world, is the lies of immortals. If you have an immortal being living among, or even ruling, over a population of mortals, though those immortals can't make up whatever religion they want immediately, they can actively direct the religious conversation until it gets them where they want. One good example of this in fiction is the Lord Ruler in the book, Mistborn, who, after around a thousand years of rule has been able to make people forget their religions and gods of old and even forget the real reason they let him be the Lord Ruler in the first place, creating a religion called the ministry of steel which nobody really knows much about, except that the slaves know mist is bad and the nobles know they have a right to rule the slaves, and that's essentially it for everyone that isn't part of the ministry of steel. If you do have immortals living among mortals, you could do something very similar, trying to determine what lies would assist the immortal in achieving his goals and what truths he would have to overcome, how long overcoming those truths would take, and what truth would remain after all that time. Religious leaders who live as long as their followers can only change religion to the degree that the conscience of their generation will allow, but an immortal among mortals does not have that limitation, meaning that if they exist you can go essentially anywhere. However, considering that the immortal among mortals is immortal, it's also pretty likely they would claim to be a god. [Answer] Monotheistic religions don't have to be catholic-focused, think of Islam, Judaism, Mandaeism, or even other Christian faiths. Alternatively, you can use a polytheistic religion with one (or a small group) being considered the most important. You could also simply not use Gods at all. This isn't unheard of, especially if you want to include lower beings (like spirits) in your religion. [Answer] Some dieties are tied to powerful emotions. Some aren't even recognized as dieties even if they have incredibly large numbers of people who have knelt and performed the tradional rituals and sacrifices. This is the story of one such diety. It's hard to determine exactly how many people have done the ritual and sacrifice, but based on the best survey evidence available, well over one Billion people in the timeline this information is being shared in have knelt and done it at least once. Millions do it fairly often. In the modern developed world, the formal version uses a proper offering basin, but even there, impromptu versions of the ritual sacrifice can be done in many settings, even outdoors on a grassy or barren field. A few those reading this have never made the ritual offering. All of you know people who have. The god of regret wants a sacrifice. He wants you to kneel before his porcelain throne and offer up your sacrifice into his ritual basin. As you pour forth the contents of your stomach, call out his name: **RAAAAAAAAAALLLLLLLPHHHHH!!!!!** [Answer] How about literal mythology and a religion surrounded by it. The chaos created galaxies, milkyway has created the Sun, the Sun has created Earth and mother Earth created the ground, the oceans and the sky from which humans have born. This mythos will stand true even today and will usher a healthy religion. If you want magic to be a part of this, you could easily integrate it. In this religion there will be multiple deities and you may even have wars within the religion itself. Outcast will worship Mars or Sun forbit, different galaxies. [Answer] Most of the answers here seem very mainstream if I'm being honest. To answer the question "How do I create a unique religion" you should just make stuff up and test how it compares to existing religions. For example, you open a dictionary and randomly select the word "pinecone"; you form a religion around it. Now you test it; you will find it strongly relates to natural religions and thus is not that original. Example two: "shapes are gods", probably harder to relate to existing religions so might be more original. Example three: the world is made up out of gods, your nose is a god, etc... Well you get it... [Answer] Whilst mythology is an element of religion, it's role is often dramatically overstated when it comes to worldbuilding. With that in mind, and observing that most other questions have focussed primarily on mythology, I will focus on the other aspects of religion. Whilst Christians will generally have at least a passing familiarity with the stories from the Bible (which in a technical Religious Studies sense are mythology) and depending on denomination, maybe some Saints' Lives and apocrypha, for many those stories are a very minor part of their actual practice (readings only make up a minority of most services, with things like prayer, communion, and hymns making up the bulk of the liturgy of the most-attended non-festival services). So instead of focussing on what your characters believe, or the mythology of their religion, you can focus on their actual practice. Even if the mythology you have in mind is still quite Greek-like, simply approaching it from this perspective will likely help keep it feeling fresh. So what are some common elements of religious practice, and what questions should you keep in mind when describing them (bear in mind that the distinction between religion and culture is far from clearcut and so this will often reference the culture as well)? * Acts: + People may perform certain actions (e.g. the sign of the cross) in various circumstances. - Is it to protect from evil or impurity? - Is it to provide the blessing of a divinity? - Does it mark them as a member of the community? - Is it to remind the person of their religious obligations? - Does it foster a sense of community (shared feasts often serve this purpose). + People may wear certain items. - This could be a small piece of jewellery (e.g. an amulet), an entire garment, or pretty much anything in between. - Is it meant to provide some protection from evil or impurity? - Does it provide a blessing? - Does it mark them as a member of the community? - Is it to remind the person of their religious obligations? * Milestones: + Milestones in peoples' lives are often ascribed religious significance. + Births: - Is the birth itself marked, or does the celebration occur later? - When is the name given? * It is common to postpone giving a name until a while after the birth, likely due to the fact infant mortality used to be so high. - Does it affect ritual purity? * Are there particular acts that must be performed at or around the birth so that the baby can achieve ritual purity (e.g. circumcision in Islam and Judaism). + Comings of Age: - When does this occur? - Does it vary by gender, class, or is it at the choice of the individual? - Do any restrictions or requirements change when this occurs? - Does it affect religious purity? - Does the person have to undergo an initiation? + Initiations: - Involve taking on a deeper level of involvement in the religion. This includes becoming a member of the clergy. - This usually involves some challenge that must be overcome, or is optional. - An initiate is then usually given extra religious roles, maybe more restrictions, maybe more requirements. - They may be taught additional secrets of the religion. - The mystery cults common in the Roman Empire often had elaborate systems of initiations, with multiple levels. + Marriages: - Who can get married? * How many people? * What genders? * What ages? * What classes? - Does one party need to pay another? Do they all? - Does a wedding require other religious practice (e.g. a sacrifice, prayers, or other ritual acts)? - Does one or more party take on additional requirements or restrictions? - Does one or more party need to undergo an initiation? - How does the religion view family life? * This is extremely broad, and deliberately so, but a religion that views the physical world as inherently corrupted by sin that humans were unfortunate to be born into (as the Bogumils are purported to have believed) is going to view marriage very differently from one that believes humans are commanded to multiply and that sex within a marriage is good and supposed to be enjoyable (as most Jews believe). + Death: - As I'm focussing on practice, I'm not going to address beliefs on what happens to the person themself when they die here, although that will likely influence the answers to these questions. - How is the body dealt with? * Is it buried? Burnt? Exposed? Mummified? - Does it need to be dealt with in a specific timespan, or can it wait? - Are additional practices required? * E.g. are prayers said, are sacrifices made, etc? - Does any of this require a member of the clergy or can an ordinary member of the community do what is required? - What are the implications for ritual purity? - Is there an ongoing mourning period? * Does it have additional restrictions or obligations? * Is the rest of the community obligated to support the mourners in some way for this period? * Are there multiple levels of mourning? * Does mourning affect ritual purity? - Is one required to take an action at a later date? * Some cultures rebury their dead after a certain time period, sometimes multiple times. Others require prayers on the anniversary of the death of a family member for a certain period. - Are there reasons to forego the usual procedure? * E.g. for criminals, or foreigners? * How does this affect those they left behind? * Prayer: + This is one pretty much everyone here will be familiar with, as it's probably the most prominent element of Christian religious practice (as many people who consider themselves Christian do not regularly read the Bible, or attend services and so do not receive communion, do still pray on occasion). + Prayers are generally about communication with the divine. - Prayers may be to request something (intercessory prayer). - Prayers may be to thank for something. - Prayers may simply be to glorify the divine (in which case their role in strengthening group identity is significant). + Are the prayers formulaic or spontaneous? - Are people expected to communicate off-the-cuff with the divine, or are there specific formulae one is supposed to use in prayers? - Are entire prayers written in advance and learnt. + Are prayers solitary or communal? - Is this a requirement or simply convention? - If communal, how does one count the quorum required? - If communal, do you need multiple people actually saying the prayer, or is it that you require people to hear it? - Does it depend on the prayer? + Are the prayers silent or out loud (and if out loud, are the spoken or sung)? + Who is able to pray? This ties in to ritual purity * Purity: + How many levels of ritual purity are there? - Is there just one level and you don't have to worry about it? Are things either pure or impure? Or are their many levels of impurity? Can you be pure for one purpose, but not for another and vice versa (i.e. are there multiple axes of ritual purity)? Is there an elevated level of purity beyond normal? + What are the implications of impurity? - Does it prevent you from participating in some required practice? Does it have consequences only in the afterlife? Are the consequences social? + How is impurity contracted? - Common sources are dead bodies, slaughtered animals, and bodily fluids, but pretty much anything can be a source of impurity, and there is a lot overlap here with restrictions. - Do you need physical contact with the source to contract it (does it need to be prolonged, or in the other direction, is merely being in an enclosed space with it sufficient)? - Maybe performing certain acts renders a person impure even if they have not come into contact with a physical source of impurity (or an item could become impure for being used in an act). + Does impurity spread? - Once impure, can a person spread that impurity to another person (a theory is that lots of beliefs around ritual purity is that they originate from attempts to conceptualise the spread of disease within the worldview of their day)? - Can one do something to stop oneself becoming impure when one normally would? E.g. does receiving the appropriate blessing allow you to not become impure when moving a dead boy, must you recite a prayer as long as you are in contact with it, must you wear an amulet etc. + How can one (or an item) become pure again? - Most commonly this involves some form of ritual washing, but the specifics can vary a lot, and may also involve things like anointing. - Items may also sometimes be purified by passing them through fire, or burying them, or passing them through a liminal state in some other way (these may also be possible for people, but are obviously rather less comfortable). - Perhaps a knife is purified for one god by passing it through fire, but for another it must be washed in running water (maybe one of the two cults also considers the other's purification process to render the knife impure, so you may need to be careful about the order you do them in if you want to use it for both). * Restrictions: + Religions don't just tell you what you should do, they often tell you things not to do. + As well as usually including some fairly universal moral instructions (e.g. killing people outside of socially accepted circumstances like war, sanctioned duels, executions etc, is bad and shouldn't be done), it can include more arbitrary-seeming restrictions. + Some restrictions come from extensions of those moral instructions due to the metaphysics of the religion (and so the mythology can be very relevant here). If you believe that a human can be reincarnated as another animal, you might start to extend some of your prohibitions against injuring humans to injuring animals, and may end up ruling that meat-eating altogether is forbidden. + Some restrictions serve to set your community apart from its neighbours. If your neighbours tattoo themselves, your community are forbidden from tattoos! This is going to be more common a motivation in cases where religion is seen as varying substantially on a local level (e.g. maybe each city has its own patron god, or the community lives as a diaspora throughout a culture that mostly practises another religion). * Sacrifice: + Who does the sacrifice: - Do you need a special member of the clergy to do it? * Are these the same clergy used for other practices, or are those who perform sacrifices a specific group within the clergy? * Can any member of the community perform the sacrifice themself? - If one isn't able to perform the sacrifice, are their restrictions on who can bring a sacrifice to be performed on their behalf? * Do you need to be ritually pure, or even in an elevated level of purity? * Is only one gender able to bring sacrifices, and does this vary between gods? + Why perform a sacrifice: - To strengthen a prayer. - To solemnise a vow (these are votive offerings). - To repair a fault. * Was the act against an individual, the community & its laws, or against a deity? * The form of the sacrifice may vary depending on this, and the lines are fuzzy. * In the first two cases the distinction between this sacrifice and a fine is solely over who is responsible for issuing/managing it (fine by civil authority, sacrifice by a spiritual one, but what if that distinction is not relevant in your society?) + What is sacrificed? - It needs to be valuable, but will also need to be accessible to the average person expected to perform it, this likely leads to a sliding scale of sacrifices from small sacrifices a struggling farmer can make, to extravagant displays from the elite of your society (so this interacts with your social structure, are those elites nobles, the high priest, merchants, generals, etc). - Does it depend on the purpose of the sacrifice or its target (e.g. money solemnises vows, but calves atone for wrongdoing; or the sun god receives sacrifices of grain whilst the earth god rejects them)? - Don't just think of animal and human sacrifice. Grain, alcohol, and money are all common sacrifices cross-culturally, and pretty much any socially significant object can be used as a sacrifice, and likely is or has been in some society (votive offerings of swords thrown in lakes are essentially sacrifices, even if not performed in a temple or with any clergy. - How is the sacrifice performed? * Does it need to be performed in a sacred space (a temple, a sacred grove, any piece of running water, etc)? * Whilst many people may prototypically think of sacrifices as destroying the item sacrificed (be that by burning, burying, leaving in the wilderness or otherwise), many times sacrifices are distributed amongst the community (after the clergy, if there are any, take their cut of course). For money this is usually distribution as charity, whilst for food and drink it may be consumed by the person making the offering (e.g. the Paschal lamb sacrificed at Passover in Second Temple Judaism was eaten by the family that brought it as a sacrifice), or it may be given to a specific other party (e.g. a sacrifice to expiate an injury to another may end up going to that person). As you can see, most of these practices (which will be the most visible aspects of the religion in the lives of the people) can happen in extremely similar ways even with wildly differing mythology behind them, and so my tweaking the practice, you can end up with a religion that feels extremely different from Greek religion without necessarily touching the mythology much at all. ]

[Question] [ In this world: Technology: medieval, it should fit with real world history, for example: * Low life life expectancy due to poor medical technology (vulnerable to disease), warfare, * High infant mortality, especially for the poor. * ... In this world, there are nobles and non-nobles (peasants). Condition to be noble: * Biological parents (both mother and father) are noble * If not sure, assume to be peasant. * The first nobles were promoted from the peasantry by the king and divine entities are suggested in folk tales. However, it has been a long time since that happened. In all official history records, there are no named peasants who were promoted to be noble. Duty: * Nobles must protect their subjects (including peasants, and other nobles). It is stated to be more important for a duke to protect his nobles vassals than his peasants. * Peasants are protected by their lord. However, this is the matter of the lord's honor (he who fails to protect his subjects is disgraced) and fortune (peasants work for their lord on his land). He should able to protect most of his peasants in time of crisis, but never risk his life for a single peasant life. However, the life of an single peasant is not important as they are expendable (peasants are likely to be punished by death, peasants in war as cannon fodder, etc.). Marriages: * Marriages requires a man and a woman (same sex marriage is forbidden by divine command). * Wife and husband can be both nobles, both peasants, or a peasant and a noble. As you see, the society is structured so that the nobles live a luxury life provided by the peasantry. It is better to be a noble. However, due to the condition of being a noble, if a noble person marries a peasant, their offspring are always peasants. Thus, in peasant bloodlines, there are noble bloodlines, but only rarely. Meanwhile, by definition, all nobles have purely noble bloodlines. This discourages nobles from marrying peasants because their offspring would no longer be noble. * I would like to ask whether it's possible for nobles and peasants to become 2 sub-species of human that cannot mate together to make offspring ? * If so, how many generations would it take? [Answer] This speciation will never occur. Why? A condition Robert A. Heinlein once described as "common bastardy." People don't *always* keep their genes to themselves. Humans are well known as what I think of as "false monogamists" even in what are considered monogamous societies. There has never been a noble class in human history that didn't "indulge itself" with the lower classes -- and indulgence of the nature I'm talking about leads to the occasional accidental pregnancy. This isn't always the duke or king producing offspring on the wrong side of the blanket, as it were, either. There are a number of well documented historical cases of noble*women* producing children that, for one reason or another, *could not have been* "legitimate." It only takes a tiny number in each generation resulting from such interbreeding to keep two otherwise separate populations within the same species. This is why humans aren't multiple species *today*: even those who (like Australian natives) were isolated from other humans for thousands of years (because they weren't; there was surely some interbreeding with people from what became Malaysia and Melanesia). [Answer] # Longer Than the Medieval Period Would Last Speciation takes a long time, save in extraordinary genetic situations ([polyploidy](https://en.wikipedia.org/wiki/Polyploidy), for instance, can create non-interbreeding hybrids in a single generation, but only in plants). Even as breeds start to diverge, interbreeding is still often possible, making definitive speciation (and definitely the kind you're talking about) difficult to call. The only *human* example we have to draw upon is the association between Neanderthals and modern humans. In that case, you had two distinct species from the same common ancestor who gradually lost the ability to interbreed. That took, at minimum, *a hundred thousand years*. This is a longer interval than human recorded history, and certainly longer than any noble/non-noble marriage rules would last. [Answer] Horses and Donkeys can mate to produce viable (if infertile in almost every case) offspring. The last common ancestor living approximately 4 million years ago. Taking a generation as 2 years that gives 2 million generations as a starting estimate. The generation time might be a little longer depending on circumstances and the time period should be a little shorter if fertile off spring are needed so say 100 thousand - 1 million generations to be on the safe side. And yes I know humans are not horses or donkeys but the same sort of genetic drift should apply to isolated groups. That said it would seem from the situation that you describe, that the noble stock might dwindle to nothing as the population is drawn off to the peasant side. [Answer] **Consanguity can rescue infertility due to a balanced translocation. It could be a speciation event.** Here is a balanced translocation in a healthy person, and an unbalanced translocation in his unfortunate progeny. [](https://i.stack.imgur.com/hfC2a.jpg) <http://infertilefarmer.blogspot.com/p/what-is-balanced-translocation.html> Balanced translocation is a common reason for infertility. The parent (depicted on top) has had a piece of one chromosome swap places with a piece of another. You need the entirety of the material from both chromosomes and he has it, just not in the regular places. But when a sperm carries half of his chromosomes off to meet and egg and make a baby, it is likely you wind up with the unbalanced scenario. 3/4 of the time you are missing a piece and the fetus has an unbalanced translocation. The mother has only unicolor chromosomes. If the mother has the same unbalanced translocation (because they are cousins) then the chance of success goes up. If dad contributes yellow with purple tip and mom contributes purple with yellow tip, all is well. The chance of conceiving is actually theoretically higher with the consanguineous union! With more than one event of this type, the chance of a person with multiple balanced translocations conceiving with anyone other than close family drops considerably. Now in the real world there are other problems with consanguineous unions / inbreeding and all of those would hold true. Persons interested in real science: do not interpret this to mean that you should produce children with close family members. But for a fiction and a method to cause consanguineous nobles to speciate out, this could happen in just a few generations. For those tempted to call B.S. - read this. [Preimplantation genetic diagnosis (PGD) for extremes--successful birth after PGD for a consanguineous couple carrying an identical balanced reciprocal translocation.](https://www-ncbi-nlm-nih-gov.proxy.library.emory.edu/pubmed/20117768) Technically skilled fertility doctors pulled off the above described feat and allowed successful birth of phenotypically normal babies from consanguineous parents carrying the same balanced translocation. The babies of course carry the same balanced translocations (they have to!) and so would themselves have the same problem as their parents. Chromosomal rearrangements (CRs) can definitely lead to speciation events! [Chromosomal Speciation in the Genomics Era: Disentangling Phylogenetic Evolution of Rock-wallabies](https://www.frontiersin.org/articles/10.3389/fgene.2017.00010/full) > > If, however, CRs generate beneficial fitness effects (spread by > positive selection), we do not expect fixation to occur at similar > times. With combined cytogenetic understanding, this allows us to fit > models to different regions along each chromosome to capture their > unique evolutionary histories. If rearrangements are important to > divergence, we expect the times at which they are established to > coincide with speciation events. > > > For your fiction, have the rearranged chromosome confer something adaptive for the nobility. They are better than the peasantry for some genetic reason - maybe immunologic, or neurologic, or magical. [Answer] **TL;DR:** Based on the genetic progression we have observed in ourselves and other species thus far, at least 300,000 years and possibly more than 700,000 years of *strict* genetic segregation would be required for humans to see an irreconcilable genetic difference between genetically-segregated humans, heralding the creation of a truly distinct species of humans. The only way such a genetic divide could have developed during a period of maybe a millenia or two of feudal rule is for some more acute reproductive change to have occurred within one population or the other. --- Speciation, the process of one species becoming genetically distinct from its parent and from any "sister species", thus unable to freely interbreed, takes quite a while. The most recently-diverged genii we are aware of are *Ursus* ("true" bears including black, brown and polar), *Canus* (dogs, wolves and coyotes), *Vulpes* (foxes), *Panthera* (large cats) and *Felis* (small cats) genii. All of these show evidence of easy hybridization among species within the genus, but they cannot freely interbreed to produce viable offspring in all combinations of mother and father and so they are indeed separate species. Which is the first problem with your posit; even if humans do diverge genetically across social strata, it's very likely that viable offspring will still be possible in at least one combination of species and sex for many millenia after that, much as we see among relatively closely-related genii. Those hybrids, whichever society they mingle with, will infuse their genetic material gained from the other group through several generations of their descendants, which will help perpetuate the close genetic relationship between species and, if these trysts are common enough, even prompt a re-merging of the species by introducing enough of what makes one population genetically incompatible into the DNA of the other population, until some critical mass is reached that allows free interbreeding again. The second problem is that even the most recently diverged genus, *Canus*, split into its extant sister species between 50,000 and 115,000 years ago. That represents about half that many generations depending on specific species and behavior, with female wolves sexually mature in a year, but not commonly leaving their birth pack until about 2-3 years of age as they're courted by unrelated males to become alphas. Extrapolating that 25,000-generation minimum to humans, with a roughly 20-year maturation period to a more socially-defined marriageable age, we'd expect even the weakest degree of speciation, losing at least one combination of parentage to nonviability, to occur over a span no shorter than 500,000 years of strict separation of the genetic stock, giving the genetic webs 25,000 generations of separation from any common ancestor. Even using the onset of female puberty (about 12 years of age) as the age of maturity and thus the minimum span between genetic generations, we're still talking about 300,000 years of genetic separation. Now, that's a minimum timeframe. It also represents about the sum total of *Homo sapiens*' existence on this planet. We know that before Neanderthal man was out-competed by anatomically modern humans spreading from the Mesopotamian region about 50,000 years ago, Neanderthals and modern humans intermingled, with every non-African population of humans retaining about 2.8% of the Neanderthal genome. That genetic mix represents a confluence of DNA previously separated by as much as 700,000 years, when the genetic branch that resulted in Neanderthals first split from our own about 860kya. Whether all combinations of Neanderthal and modern human, male and female, produced viable offspring (and therefore *H. neanderthalensis* and *H. sapiens* were still genetically the same species) is unknown, but it's unlikely, given the proliferation of Neanderthal DNA in the human genome, that this was a rare occurrence. So, while 25,000 generations is a minimum timeframe, giving us a neighborhood of between 300k and 500k years to start seeing genetic speciation happen in genetically-segregated humans, we also have archaeological evidence that anatomically modern humans didn't truly segregate from Neanderthal cousins over a timeframe up to twice that long. At the upper end of canine speciation estimates and human maturities, we might expect genetically-segregated humans to truly speciate on a timescale of a million years (but still produce viable hybrids from the male of one species and the female of the other). In any case, expecting it to happen naturally as the result of even a couple millenia of social segregation between cohabiting human populations just doesn't pass the smell test. --- So, the only feasible scenario for your worldbuilding is that some more acute genetic mutation has rendered the nobility incapable of producing viable offspring with the rest of humanity. This mutation could be environmental in nature, or could arise quite simply by inbreeding among a small genetic population. The first device is a fairly easy handwave and it's been done before. In the video game *Freelancer*, the Outcasts are the descendants of one tribe of the doomed sleeper ship *Hispania*, and landed on a planet with a predominant form of plantlife that ended up altering the Outcasts at a genetic level, making them unable to tolerate being away from the Outcast homeworld Malta for any extended period without a supply of an extract of the plant, called cardamine. In another example, the *Divergent Series* novels and movies ultimately reveal Triss's home city of Chicago to be an experiment by a far more advanced branch of humanity that survived a global war. Chicago's inhabitants were genetically damaged by weapons used in that war, limiting their inherent human traits, and the experiment, run by the descendants of humanity who escaped such weapons, sought to find out whether the genetic damage would naturally heal over time. Divergents, ostracised and hunted down as undesirable by Chicago's leadership (totally unaware of the experiment), turn out to be exactly what the experiment was intended to produce, as individuals' genomes repaired themselves over generations. Reproductive difficulties weren't covered specifically, but this is an obvious direction to take an underlying story about a society of genetically-damaged individuals. The second device, simple inbreeding, has pretty sound basis in our own reality. Estimates of the "minimum viable population" of a genetically random or localized population hover around 4,000 individuals; any fewer than that and you will, given sufficient time, see symptoms of inbreeding caused by insufficient genetic diversity. You can make do with a smaller population if that population is more genetically diverse, down to a minimum hypothetical "ark population" of approximately 500 individuals, specifically selected from across the entire human species to maximize diversity across the genome, and then the proper sequence of reproductive pairings "arranged" through each generation, stud-book style, to disseminate that genetic diversity as efficiently as possible. As of the creation of Great Britain in 1707 by the formal merging of the crowns of England and Scotland (which had rested on the same head since James VI of Scotland inherited the English crown from his cousin Elizabeth I in 1603 to become "James VI and I"), the "peerage" or nobility of both predecessor nations numbered only 322 individuals and their extended families. Let's say the average family size, including only children surviving to have their own children, was 5; that's only 1500 individuals in a roughly steady-state population, many of which could likely already trace their familial relationship to most of the rest of the peerage within four degrees of blood or marriage on *both* sides of their family tree, well below the 4,000 minimum viability of a random localized genetic sampling. It's a long-running joke that the English nobility have kept it in the family just a few generations too many, and while both the sons of Charles and Diana have married and had children outside the nobility, Prince George (William and Kate's eldest son) is the first person in line to the British throne that I can find since the Tudor era (Edward VI, son of Jane Seymour) to not have two parents of noble birth. [Answer] In medieval terms.. the children of peasants and nobles always fail to thrive; you don't need any more detail than that. It could be caused by the noble females, being closely related, all carrying an incredibly rare mitochondrial mutation x, being a mitochondrial mutation it is passed unchanged to all of their offspring. Some noble males carry an equally rare mutation y. Inheriting x without y will lead to the offspring being infertile, or not surviving to adulthood. A noblewoman can then never, successfully, have a peasant's child. Some noble-noble offspring would fail, because they may not inherit y from their fathers (~50%) all noble-peasant offspring would die. You would also have to make mutation y fatal on it's own, to close the loop and prevent peasant-noble children from inheriting it and passing it on. Depending on how the original nobles were selected, this could have happened from day 1. If the original noblewomen were selected form a specific group or tribe (or maybe they were from a foreign land, due to the otherworldliness) they may have all carried this mutation which was not present in the native population [Answer] It’s “just” a matter of random mutations. It’s highly unlikely but if it’s important for your story you could have it happen within a few generations. The nobles could even point out how special and unlikely it is and that it’s certainly a sign of divine benediction. [Answer] Without evolutionary pressure, the answer is never. Evolutionary change comes from random mutations plus an environmental factor that selects for that change. If random mutations happen within individual nobles and peasants, but nature doesn't effectively favor these individuals, then these mutations won't become "norm" in the population. If no large changes happen in the populations, then there's no reason to think their reproductive systems will become cross-incompatible. Nature is rife with evolutionary pressure, as species fight for resources, migration brings new competitors in, weather patters change over thousands of years. Human society, even a medieval one, doesn't have nearly as much pressure. Societal factors (who you were born to, what you receive for education, etc) determine your breeding patterns, not being on average bigger or better. [Answer] In reality: not in a time scale that is compatible with any sort of society we're familiar with. Others have covered this well, I have nothing to add on that. There are workarounds for this, for example you could invoke divine favor to keep this society going for a Really Long Time. As long as you're not trying to maintain real-world astrophysics and follow the recipes in How To Build a Habitable Planet and generally maintain nerd-compliant reality, there's plenty of precedent for an "it's always been there" society, and this can be a reasonable occasion for suspension of disbelief. You've already established that there's a deity on the scene, so we're already outside of nerd-compliant reality anyway. This has the added advantage of offering infinite scope for Other Tales. However, there is one basic problem that I think torpedos the idea for me, and that is that it's plot-wise inconsistent with your setup, under "nobles and peasants marry and produce offspring" is part of the background. I don't see how you can preserve this in your setup and still get the speciation, without invoking a lot more magic than I'd be willing to tolerate under "suspension of disbelief". [Answer] **Ruddy ducks!** For one animal species, the answer is well in excess of ten million years, and that's a minimum. It might be as much as 50 million years during which it didn't happen. When the Atlantic Ocean opened, it separated two populations of ducks. One evolved into the North American Ruddy Duck, the other into the European White-headed duck. They have completely different plumage, and were classified as different species. But when humans unwisely introduced Ruddy ducks into Europe, they immediately started breeding! I have read that female white-headed ducks actually preferred ruddy ducks as mates. Humans have decided that such hybridisation is not a good idea and have shot the ruddy duck and obvious hybrid ducks in Europe to extinction, although it's virtually certain that some ruddy duck genes have entered the gene pool of the white-headed ducks. The strongest definition of species is that the organisms cannot interbreed and produce healthy fertile offspring are separate species. A lesser definition is that two species choose not to, or simply can't for geographical reasons. This was a case of can't, because of the width of the ocean. As soon as humans bridged it for them, they did, with enthusiasm! <https://www.rspb.org.uk/our-work/our-positions-and-casework/our-positions/species/invasive-non-native-species/ruddy-ducks-and-white-headed-ducks/> [Answer] Speciation requires two things to happen: firstly a new gene in one individual of Population A that prevents successful fertilisation with Population B, and perhaps other genes conferring survival success. Then a period while the new gene becomes established in population A. The first takes no time at all, so the second is the limiting factor time-wise. If we assume ten surviving children per couple, every generation, 8 generations would get us to 100 million, which is enough to be called "established" in most populations, though there might still be a few individuals that could interbreed. So assuming 20 years per generation, we are only talking about **160 years**. The probability of this happening is extremely remote, but definitely possible. If you want something that is more likely, it would require more time, but is always going to require that first mutation. Absolutely nothing to do with species (e.g dogs and wolves) where this has NOT happened. [Answer] The speed of the "speciacion" depends on both mutation pressure, selection pressure and the quality of the separation between populations. As per your scheme, peasant population is not insulated by definition. Medieval science and technology (and human nature in general) imply that no actual control of gene transfer can be implemented. In the wild, it takes a tall mountain or clima belt to separate populations of plants or animals. So long for separation. Selection pressure difference: we can assume there is little to none in the nobble and at best medicore in the peasants. Common factors (e.g. diseases) will affect equally both. No luck there either. Mutation pressure: who knows. No ionizing radiation, probably some poisons used by the nobble and that's all for medieval setup. [Answer] Pockets of humanity have been cut off from contact from others for thousands of years at a time and this physical separation between populations did not result in speciation. The administrative separation within your populations would not have a more marked effect than an actual physical separation. [Answer] The normal process of speciation tends to require: * A relatively small population. * ..that is isolated from interaction with surrounding populations * ..that has significant divergent selection mechanisms acting on it. Google "punctuated equilibrium" evolution including the quotes. Look at dogs. We've had dogs with us for tens of thousands of years, and have been imposing our selections on them for a few thousand years. But all dogs are still considered the same species, and as far as I know they can all interbreed. Dogs, wolves, and coyotes are considered separate species, although they can successfully interbreed. Anyway, with domestic dogs, you would typically have a selected litter (after proving your worth to your owner) probably an average of 3 yr per generation. If we suppose serious selection only from the time we were able to pen the females separately when in heat, call it, what, 4000 years. So with 1000 to 2000 generations (lots of handwavium) we don't have separate species, although the mechanics of breeding chihuahuas and great danes would be interesting. I think you could make a case for wheat being a different species from the grain it started from, ditto corn. On the other hand, cabbage, kale, broccoli, cauliflower, brussel sprouts, and kohlrabi are all the same species. Humans tend to see well formed strangers as attractive. The exotic look. There is a strong drive to hybridize. The longest case I can think of right now of population isolation is that of Australia. People were separated for at least 40K years, from the rest of the world. But perhaps the population was too large for genetic drift to occur. If you want to make this plausible, you need some agency putting strong selection pressure, and isolation pressure between populations, but this requires a degree of institutional permanence that humanity hasn't exhibited. From the examples above, I'd estimate 10,000 generations at a minimum to get to the non-viability of hybrids. * Your culture is the property of a very long lived alien. It acts like a dog breeder when his best bitch has been bred to a mongrel: Drown the pups. * There are gods. (Aliens with a different label) * There is magic. A compulsion that forbids certain unions. [Answer] We can try and do this in reverse. First stop them from interbreeding, then have them evolve differently ([sympatric speciation](https://en.wikipedia.org/wiki/Sympatry)). We cheat, introducing *devilgrass*. This is a very nourishing, sturdy perennial plant that is almost ubiquitous (an infestant, actually); it was rarely used as food since it's also poisonous, and requires special cooking to be digestible. Even so, it can trigger a case of the runs, and worst case, [impairs platelet activity in the body](https://en.wikipedia.org/wiki/Mechanism_of_action_of_aspirin), resulting in haemorraging. But during harsh winters there is often no other easy resource. So, in the dim past, people started eating devilgrass (that's how the [special cooking](https://en.wikipedia.org/wiki/Nixtamalization) was discovered). Then a random, recessive mutation happened that changed the cyclooxigenase mechanism in some peasant. As a result, they became partially immune to the devilgrass poison. The mutation evolved, but it never "took" among the nobles, since no noble can have a peasant ancestor. Villages where the mutation ruled routinely had a population excess, so naturally their Devilgrass-Resistant (D/R) population tended to spread to nearby villages, even colonizing wholesale whenever famine and sickness had led to some of those being abandoned. Within thirty reproductive cycles, say one thousand years, a large area has D/R peasants only: as soon as the D/R ratio rises too much, devilgrass cooking stops, which forces D/S peasants to flee, die, spend for healthier fare, or devote much more time than the new normal to cooking. Now the mutation has evolved to the point that the "old" and "new" style ciclooxygenase mechanisms begin interfering. There are no less than five different COX alleles around, Noble0 and Peasant1 through Peasant4. The larger the index, the more marked the devilgrass immunity (the Peasant1 allele is almost extinct even though it spread the farthest, replaced almost everywhere by at least the P2); and the larger the *difference* between the indexes, [the higher the chances of a spontaneous abortion](https://www.ncbi.nlm.nih.gov/pubmed/20819509). P44 children are healthy and always come to term. Most P41 die stillborn. The children of a noble and a P1 almost always survive, but won't live long because they need specially cooked food. The children of a noble and a P4 never come to term. It will take anywhere between twenty and one hundred centuries even so (you could greatly accelerate times with some unwitting eugenics - say some religion preaching that devilgrass sensitivity is a sign of impurity and evil unless one is a noble, in which case the reverse applies. So you should never, ever marry a D/S individual, or fight to allow a D/S child survive. God wishes it so). But in the end, a noble might take a peasant lover and neither should worry about a pregnancy (again, God wishes it so). The two "species" were always different however: the different diet ensured nobles were routinely taller and straighter than peasants (the same difference exists between moderns and ancient Romans). Now they can start diverging in earnest. [Answer] H.G. Wells' novel *The Time Machine*. Made into a movie by George Pal. In the movie, some humans went down into bomb shelters and learned to survive there, while others stayed up top, and they evolved to be pretty different [Answer] The Japanese novel [Shin Sekai Yori (eng: From the New World) (2008)](https://en.wikipedia.org/wiki/From_the_New_World_(novel)) covers this rather graphically and specifically. Starting from (apparently) random mutations in the late 20st century, a psychic overclass develops after non-psychic (or degenerate-psychic) humans are systematically murdered and/or altered physically to new, animalistic forms. The "present-day" of the story is set about 3000 years in the future, but even then, even with active and purposeful social, genetic, & physiological manipulation, the underclass and overclass are still genetically a single species. Octavia Butler's [Patternist series](https://en.wikipedia.org/wiki/Patternist_series) covers similar ground, but that involves alien parasites, so may not quite be what you're looking for. [Answer] As others have already said, the process of species-divergence would take far too long, even if you assume that nobody in either population would stray. And even if two populations did evolve into separate species, there would be no guarantee that they still couldn't interbreed. However, if you're more interested in the scenario where two populations cannot interbreed -- but they are not necessarily separate species -- then I propose the following idea: There are certain foods that are considered "class-specific" foods. That is, some foods are considered to be appropriate only for the upper class, and some foods are considered appropriate for the lower class. It just so happens that a certain "upper-class" food is poisonous to people who carry a certain gene. It also so happens that a certain "lower-class" food is poisonous to people who carry a different gene. What will happen over time? Over time, those in the upper class with the problem gene will die out, making it less likely that that gene is passed to their descendants. And the same thing will happen with the lower class, in that their own problem gene eventually disappears from their population. So the upper class no longer has gene A, and the lower class no longer has gene B. Now, suppose these two genes are crucial to reproduction; every member of this species has to have exactly one of gene A or gene B to survive childbirth and/or conception. Having both (or neither) won't work, in that a child can't live with both the A and B genes. Assuming that each parent must give their A or B gene to the child, the fact that a mixed-class child would necessarily have both would spell its doom. In this way you can have two separate populations of the same species that could not interbreed. Your fictional characters may or may not know about genetics (whether they do is up to you), but if they don't, then they could consider the offspring-less unions of mixed classes to be proof that classes are not supposed to be mixed. Now you might ask: Hey, if the upper classes originally had gene A and then lost it, wouldn't it necessarily mean that they had both genes A and B at one time a long time ago? (And the same problem with the lower classes.) Yes, that could be. But there are work-arounds you can consider: Maybe there once was a C gene (that is now gone) that allowed for mixing of A and B genes during olden times. Or maybe the A and/or B gene(s) evolved a bit to be slightly different today than it was centuries ago. Or maybe these fictional people aren't quite human like we are, and follow slightly different rules of evolution. Even in humans, there are certain genetic conditions (such as [Hemolytic disease of the newborn](https://en.wikipedia.org/wiki/Hemolytic_disease_of_the_newborn)) that can cause difficult childbirth. So it's not too much of a stretch to figure out a case where the sexual union of people of two different populations (of the same species) can cause problems in reproduction. In the end, it's up to you. ]

[Question] [ Usually this "indestructible" material is unnaturally strong for its weight; the armor "just exists" and doesn't go into the feasibility of such a material. Given that the material isn't "hard to obtain" (*anybody is capable of obtaining the armor*) and passive (*no type of "energy" should be required for it to work*), how might I explain that nobody simply creates bullets or other offensive items that are made out of the same material in order to overcome the armor? [Answer] Make the material flexible. Consider Kevlar: it's an ultra-strong fiber that can be woven into sheets of highly tear-resistant fabric. Thick, interlocked layers of this fabric are used to spread the force of a bullet out over a large area. Using it to make a weapon just doesn't work: it's too light to make an effective bullet, too floppy for a long-rod penetrator, and even if you somehow make it stiff enough to look like a sword, it can't hold an edge worth mentioning. I suppose you can make a Kevlar whip, but you'd look rather silly running around a battlefield with one. Your indestructible armor would be an "ultra-Kevlar": strong enough to resist cutting (swords) as well as tearing (bullets), but not stiff enough to make a sensible weapon. [Answer] Give it a very high strength to weight ratio. A material that is very strong but weighs almost nothing would be lousy for any kind of weapon that relies on mass. A bullet made of aerogel or styrofoam isn't going to do any real damage, especially if you are firing it at something as hard as steel. At any distance the air resistance will simply rob it of all inertia and drop it out of the air. It could be used as an unbreakable line, but as a weapon there aren't many advantages to that over normal braided steel cable. On a side note, you could braid a space elevator with it, which would be awesome! [Answer] I second the kevlar answer, but here are soe thoughts as well. There is such thing as [non-Newtonian fluid](https://en.wikipedia.org/wiki/Non-Newtonian_fluid) which flows quite easily when pushed slowly but becomes almost rigid when you hit it. Google videos, they are fun - very filthy fun. Can be made at home as well. One could theorize about a non-Newtonian cloth or plastic which is soft and elastic when moved slowly, but extremely rigid and tough when accelerated and/or deformed rapidly. Such material would be a godsend when it comes to armor: you can move, walk, run, jump all the way you want, but a bullet or club will only push, rotate, and shake you in the same pose you were before the hit. No more broken bones (but you can still suffer concussion if the projectile has enough impulse). However, such property is useless for weapons. Make a sword that what, deforms when you swing it and stiffens when it hits the target? Would make for great supersonic whips though, but this type of armor should be immune to whipping. The armor can still be penetrated by slowly moving knife, think [Frank Herbert's Dune](https://en.wikipedia.org/wiki/Holtzman_effect#Holtzman_shield). Maybe physical armor (unlike force shield) could be strengthened by layers of kevlar or something. I can also think of a sonic weapon which doesn't harm the enemy per se but binds them in place because the armor reacts to vibration as it would to a hit or fall. But still it's a great armor overall, and no benefits for making weapons. [Answer] The simplest answer to the question *Why don't they turn it into weapons* is... **They don't need to.** In no logically consistent world will this material be as cheap as standard armor and munitions...more people will want it meaning cost will matter so making munitions out of it makes less and less sense. At a certain point the limiting factor in an armored human scenario **is the human**. Your armor may be able to take a hit from a tank shell without being damaged but that is irrelevant because the human on the inside would end up liquified. Blades would be pretty worthless unless you are talking about a heavy two hander (they are better for blunt damage than piercing/slashing). * Fire still works. Heat up the armor, it may still be shiny but it will have a cooked person inside. * Blunt damage still works. Hit an armored human with a heavy enough weight and the armor is irrelevant. * Electricity...still works unless your armor is an insulator. * Water. Armor is generally heavy, it's hard to swim with armor on...even kevlar. * Standard munitions (larger calibers) still work too. A .50 cal vehicle mounted machine gun can kill without actually hitting a human target, the velocity alone can snap necks and other bones... [Answer] **Indestructible weaponry isn't a problem for indestructible armor (or even necessarily destructible armor).** The goal of armor is not to break the weapon, but rather to protect the user. For a real world analogy, consider a bullet-proof vest. If someone shoots you, the vest functions by stopping the bullet before it penetrates your body and it protects you, despite the fact that the bullet was not "destroyed" (although it may end up squished). In fact, someone could shoot an ordinary kevlar vest with an indestructible bullet, and it might get a little further into the vest as it doesn't lose energy to being squished, but the vest would still function. So, indestructible weaponry isn't even necessarily a problem for normal armor. Why would it be a problem for indestructible armor? Anything that comes at you just bounces off your armor. Of course, it is notable that one feels a large impact if they are shot wearing a bullet-proof vest, since all that energy and momentum has to go somewhere. Such an armor would be useful to people, but it can only do so much: If a tank shoots you, there's just too much energy and momentum there for you to survive, regardless of whether the shell actually hits you - so weapons made of lesser materials can still overcome indestructible armor. That said, if you start armoring machines and buildings in this stuff (i.e. things that are less sensitive to changes in momentum), there's not much an adversary can do. [Answer] Warning: attempt at internally-consistent handwaving. Based on answers clarifying what asker is trying to achieve, I see only one explanation: Make it susceptible to acceleration. Normal materials are concerned with force, not acceleration, and break apart if applied force is greater than for example it's tensile strength. This material is different: no matter what force is applied, it becomes relatively fragile when it accelerates (this is "the big lie", rest is derived from this quality). Even accelerating, it can easily outperform ordinary materials, but it's the strongest when it's still or moving at constant speed, easily defeating bullets made of same material. In practice, this means that it's great for construction, or perfect for armours and non-moving parts of weapons (like barrels, but not locks, at least not without extreme redesign) but terrible for blades, bullets or shells: [9 mm bullet](https://en.wikipedia.org/wiki/9%C3%9719mm_Parabellum) weights about 100 grams and is moving at 400 m/s giving it momentum of 40 kg\*m/s, same as 80 kg human moving at 0.5 m/s. During impact, bullet is subject to extreme deceleration while it transfers almost all of it's momentum to wearer, wearer on the other hand is only slightly affected - bullet becomes much more fragile than armour and shatters. This means, that humans wearing such armour are completely immune to small arms fire, and any "indestructible" projectile lighter than target (assuming target isn't anchored in any way) will shatter and has to rely on other properties than penetration to make a kill (120mm Abrams cannon: ~8 kg projectile, 1700 m/s, after impact 80 kg wearer would be sent flying at ~150 m/s, which without liquid breathing should kill him anyway, but shell is subjected to almost 10 times higher acceleration than armour), which means that "indestructible" projectile has no advantage over normal projectile. In practice, this remarkable property would have very interesting impact on modern battlefield: armoured infantry becomes immune to shrapnel and small arms fire, airburst bombs and artillery become completely ineffective because ground itself protects from acceleration/deceleration. The main way to kill infantry is to use projectiles and explosions intended to send them flying, killing them within armour. Infantry on the other hand is most likely equipped with some means to quickly anchor themselves to the ground/surrounding for increased protection when located in exposed or otherwise dangerous spot. As technology develops, increased weight of powered armour becomes a great boon, in addition, anchors can easily become part of armour, deploying automatically when radar detects incoming fire ([same as anti-missile systems used on modern tanks](https://en.wikipedia.org/wiki/Active_protection_system#Hardkill_measures)). The only sure way to kill, is to use shell heavier than target, while target is in air or space. Edit to explore effects a bit more: Tanks become effectively immune to any regular weapons, but are not cost effective compared to infantry, infantry on the other hand is completely immune to regular weapons wielded by other infantry, this heavily changes infantry tactics: * use flamethrowers to cook them alive * hand to hand combat to subdue enemy and either physically kick out of borders, or drown/bury alive (could take a while if internal oxygen tanks become regular part of armour) * Weaponise whatever production process is used to shape this material * much higher reliance on flash-bangs and other means to incapacitate enemy while you are getting close to pry him out of his armour Anti-tank tactics: * Flame-throwers (again) * charges (mines, bombs, precision shells and missiles) designed to flip tank around, taking it out of action without destroying it * Weapons intended to take out cameras, and obscure vision ports, rendering tank inoperable (smoke bombs? guided double warhead tar-and-feathers missiles?) and let infantry take it all the way down with flamthrowers. In practice that removes tanks from battlefield, because increase in protection over infantry is not worth costs and loss in versatility and mobility, unless tanks can carry weapons that CAN damage this material while same weapons are impractical for infantry. For example, tanks could use laser/plasma weapons which are too big even for powered armours (something about fusion chamber sizes and energy requirement necessitating use of reactors?) but can penetrate this astounding material. The way I see it, end result is a mess where infantry fights each other in melee and literally dismantles tanks if let close, while tanks rule supreme in open terrain. Hmm, it's not actually THAT different. [Answer] I think your analogy is flawed. You are assuming that armor made from material X is unnaturally strong; so a weapon made from material X should also be unnaturally powerful(kind of like a diamond-tipped saw is required to cut diamonds). Flaw in this logic is that the weapon and the armor are made using different goals in mind: Weapon needs to damage the enemy, not his armor. If I were to use a flamethrower or EMP on a person wearing said armor, the armor won't need to be penetrated to kill the person. Also, as Milo Brandt said in his answer, such material will only yield indestructible weapons, not unbeatable ones. Here's a joke question to clarify the idea: > > If the black box in an airplane is never destroyed in a crash, why isn't the entire plane made of that stuff? > > > [Answer] **Make it impact sensitive** The material, like [corn starch water mix](https://www.youtube.com/watch?v=Vx2DjGwnd44) becomes very hard only briefly on impact. This works well for armour as a layer of this material could be contained in the protective armour in pockets of another material or through some other containment system. However if making bullets or blades this becomes completely useless as the moment they are not being hit against something they turn to fluid and drain away. [Answer] Simplest answer. The real reason to not use an indestructible material for making weapons. **It is indestructible** That means that you cannot not damage it. Which means you cannot shape it, sharpen it, or generally work it. Ergo, if the raw material wasn't weapon shaped to begin with, it can never be weapon shaped. The up shot of this is, how did it become armor shaped? Well the material could come in a variety of plate shapes, which would be woven together into some sort of plate armor. [Answer] It might be that the material would be prohibitively expensive to make bullets out of it. Body armor that's made from a basically indestructible material would last basically forever. So, it's really expensive, but it's a one time purchase. If you could make a bullet out of that material that might not in and of itself be enough to defeat the armor. You might need to hit the same exact spot in the armor 10, 15 or 100 times to break it because of the way it's layered or hardened or whatever other way you explain it. So in that example, while technically, it could be destroyed by a projectile of the same material, it's effectively indestructible because nobody would buy bullets at $10,000 a round when there isn't even a guarantee that they will take the target out. It would be better to train people to make very precise shots with cheap ammo. It gives you more story hooks and is more interesting for things to have some weakness. Maybe there is one multi billionaire that can afford one all out attack with super bullets on one person and it bankrupts them. Weaknesses give you cool things to write about. I think that's why Superman has a weaknesses. Otherwise, where's the story? He just wins. [Answer] Suppose the process of manufacturing the armor produces a material that is lightweight and indestructible. It cannot even be dented. Suppose further that the process can be modified so that the finished product is of any size and shape we want, within reason. I'll call this material "unobtainium." To counter the question, why wouldn't people make weapons of unobtainium in order to overcome the armor, the response is: how would that work? Imagine we fired a twenty-first-century anti-tank round at a soldier armored in unobtainium, and suppose the soldier is well enough braced (e.g. against a wall) so that the impact of the round does not just knock him over. What happens? The round cannot pierce or deform the armor. It strikes the armor with great force, but the armor pushes back (Newton's laws). The reaction force may deform the anti-tank round (in fact I think it almost surely will do so) or cause it to bounce back, or both. Now put a full jacket of unobtainium around a similar anti-tank round and fire it at the same armored soldier. What happens? I claim that the round still exerts force on the armor and the armor still pushes back with an equal and opposite force. The difference is that this time, the unobtainium jacket prevents the anti-tank round from deforming. But it does not prevent it from *bouncing off,* which I believe is exactly what it would do. An unobtainium-jacketed anti-tank round would indeed be useful as a weapon against twenty-first-century tanks: their armor is not nearly as tough as unobtainium, so a round fired with sufficient force is sure to penetrate. But if nobody is using twenty-first-century tanks in your world, the ability to pierce that armor is not worth anything. In fact, the main thing stopping you from shooting a projectile through unobtainium armor is not the strength of your projectile, it's the inability to put enough energy and momentum into *any* projectile in order to overcome the armor's incredible strength. (Non-projectile weapons are even worse; the amount of energy and momentum you can put into a sword by swinging it is *very* limited.) So to fight unobtainium-armored soldiers, you need to get around the armor, or find something (a force-field "blade" perhaps) that can disrupt whatever material properties give unobtainium its strength; you could shoot something at a walking soldier with enough momentum to knock him over or at least slow him down, or simply hit the armor with something that imparts so much momentum to the soldier that his bones and/or organs are injured by the acceleration, killing or disabling him. None of this implies that these weapons would be made from unobtainium. --- Warning: extreme physics-geek talk below this line. Delving into the physics a little deeper, the force on the anti-tank round has to be exerted through some distance in order to reverse the direction of the round. Since the force occurs only when the unobtainium jacket touches the unobtainium armor, and neither of these can deform, how can the force act through a distance? I suppose that when we say unobtainium cannot be deformed, we mean it cannot be deformed on a macroscopic scale (anything you could measure with a ruler or even a micrometer); but it still consists of atomic nuclei and some kind of cloud of electrons, and as these components of the jacket approach these components of the armor, there is an electric repulsive force that becomes significant only when the gap between the objects is not much more than the distance between the nuclei, and that it rapidly increases as the objects approach nearer. This rapidly-increasing force provides the "springiness" that allows two colliding pieces of unobtainium to bounce off each other. [Answer] If its indestructible and cheap, then turning it into a weapon would be pointless because everyone else is indestructible. If this unobtanium is super cheap, then everyone will have it. If everyone will have it, everyone will be "indestructible". If everyone is indestructible, then no one can be killed by weapons, and if no one can be killed by weapons then weapons become pretty useless. [Answer] An exotic option that, as far as I can tell, evades many of the mentioned creative workarounds the other answers have: If you're willing to go the way of [vibranium](https://en.wikipedia.org/wiki/Vibranium) (Captain America's shield, absorbs kinetic energy), have a material with unusual inertial properties, like a solid-state equivalent of a spinning flywheel. Perhaps possessing huge inertia regardless of mass, possibly manifesting at greater intensity the greater the attempted speed of change. Superb protection against high-velocity impacts. Mediocre protection against melee-speed weapons. Movement impediment, possibly "tunable" to a small degree, letting you find your preferred balance of low-velocity protection and freedom of movement. The "indestructability" part could come in a related flavor, letting the material be workable at low speeds, but otherwise resisting with a force roughly proportional to the mass of the piece (thus affecting design, and maybe still leaving steel superior for small pieces, justifying vulnerabilities and similarities to our world). It would, at best, make a functional mace, though the property trade-off may still make it *less practical* than many alternatives. Not impossible, just an inferior idea. As projectiles, I suppose they could be used in a [long rifle](https://en.wikipedia.org/wiki/Long_rifle) if you held it steady long enough, though maybe not much better than a sling. What if you wanted to use them as tiny bullets packing a huge punch? I suppose small mass, air drag, and a need to put together a larger piece of the material to make use of the properties, could take care of that. Or low temperature tolerance. This could make for a separate SE question. [Rods from God](https://en.wikipedia.org/wiki/Kinetic_bombardment), though? Goodbye, continents. [Answer] I can think of two explanations: 1. Too heavy - Regardless of how high a material's strength to weight ratio is, it still may be impossible to make a weapon out of it that's light enough to wield. 2. Too soft - A soft but strong material can certainly be made to absorb energy well enough to make effective armour, think Kevlar. However, that same ability could make it useless as a weapon. That's exactly why militaries tend to use jacketed ammunition, lead is to soft to penetrate armour properly. [Answer] Another answer could be that the material becomes exponentially stronger in relation to the size of a given piece of it. In the same way a large mass has more gravity, larger pieces of this material could be much stronger. Pieces small enough to be wielded, would be weak and break apart easily while a contiguous piece of it the size of a suit might be able to withstand an atomic blast. Once you get past a certain size (size of a suit or maybe smaller), It might get tougher, but it doesn't matter because at the size of a suit, it can withstand being tossed into the sun. [Answer] There is a real life example of such a thing: Big safes or bank vaults. Yes, they could be destroyed, but it is impractical enough to do so that they are effectively considered indestructible. And the materials they are made of - concrete, hard steel - are not difficult to come by at all... ]

[Question] [ ## An engineering enigma: the useless "wings" behind giant robots. [](https://i.stack.imgur.com/OhzbV.png) > > "Bold design choice." > > > "What? I like anime." > > > "Worst-case scenario, we'll end up with the world's most expensive > Gundam model." > > > ―Tony Stark and Erik Killmonger > > > ## More than an aesthetic choice: **[Mecha](https://en.wikipedia.org/wiki/Mecha)** are a staple memorable aspect of Japanese media. Who doesn't love the sight of implausibly large robots duking it out? In some cases, the creators go as far as to take inspiration from real technology to make their designs feel more grounded in reality. If you know the saying **"form follows function"** you know where I am going with this. A common design choice in mecha is to endow them with little wings or spikes on their backs (look at the image above). I like details like these, it adds to the silhouette of the robots and makes them look more imposing. **While I know it is just an aesthetic choice, I want to uncover their true purpose from an engineering standpoint.** ## Potential uses? **Looking at the "wings" at face value, they do not participate in any sort of mechanical movement. Typically they move on an x y axis: bending up, down and shifting their angle sideways.** Only in some instances do the wings serve as thrusters, usually backing up the main thrusters situated in the legs. The mecha desings tend to have exaggerated busts, possibly as protection for the core, so the wings may serve for balance? They do not seem particularly designed for being antennae either, the head would be a better placement I assume. That leaves us with cooling, which may be accomplished by multiple means. As a rebuttal for that theory we never see any exhaust from the spikes. ## The real goal here: If you have read this far without downvoting it means you are invested in the potential function of mecha "wings". My goal here isn't to ask a random question about giant robots. **What I want is a functional application of these limbs to better design my own robots accordingly. Doing "whatever I think is best" isn't my style, I prefer facts and data that adds that sweet taste of realism to fiction.** [Edited] **Wait... what were the giant robots used for again? Media portrays them as war machines. I'm using them for my robot designs, especially the larger robots. Their purpose is more mundane like as construction robots or as vehicles to explore hostile environments.** The technology level is futuristic. Note that a "mecha" doesn't need to be skyscraper-sized, a human-sized machine can still be considered a mecha. **Answers should present a given function for the "wings" and explain WHY this design choice would be logical from an engineering standpoint.** [Answer] # A few thoughts: Your suggestions are actually not as bad as you think. Antennae could be built into such structures, but routine communications are likely handled by the smaller ones mounted on the head. Radiators aren't a bad idea, and they wouldn't vent exhaust because their job would be to get hot, not output smoke or steam. * **Steering**: If your robot has jet assist, they may act not as rockets, but to deflect the jets in various directions to control flight. While your robots are far from aerodynamic, a few small control surfaces (especially directing exhaust gasses) could really help. * **Rocket armor**: These robots are often portrayed bristling with numerous small rocket launchers. They could either contain sleeves of such rockets within, or deploy in such a way as to cover up such batteries to prevent damage. They might even be able to deploy the equivalent of shields to drop over the most vulnerable spots on the body or to cover up damaged locations where the armor has been degraded. * **Loading arms**: On the same vein, these could be mechanisms used to load ammunition into the mecha. When backed up to an ammunition vehicle, these arms mate with loaders on the vehicle and allow super-fast flow of missiles, shells, bullets, or fuel pods. The high-explosive rounds never have to leave a protected environment. Such dedicated loaders might explain why we never see mecha backed up on the battlefield waiting to reload missiles that they seem to fire off constantly like confetti. * **The un-sexy backpack**: The less exciting use of these arms is to secure fuel, food and ammunition pods onto the mecha so they can operate autonomously away from supply vehicles. Such awkward, ungainly and ugly attachments are used up and dropped, or detached during battle to prevent damage. The arms of the mecha are limited to what they can do. These things can directly pump fuel from pods and pick up items from behind the mecha that the effective but poorly adapted front arms simply can't. * **Identification**: These could be the ultra-modern equivalent to banners carried into battle. All your mecha have the same basic ones, and an enemy would be executed as a spy if he tried to imitate it - it's like putting on a uniform. So what if you don't want them all the same? While jamming can make comm traffic impossible, and IFF equipment can be tricked by electronic counter-measures, the potential pleomorphic nature of these added (and possibly non/low-functional components) parts means that a unit can see that there is Steve with his orange and brown stipes waving in the air like he does. Bob NEVER puts his wings up like that, I think that's really an enemy pretending to be an ally! * **Folding wings/deployable equipment**: What you see is not what you get. These are the mounting points of large deployable wings or parasails that guide the mecha as they fall from drop ships, then fold up or drop off on landing. Or maybe these are where the mecha is mounted inside the drop ships to keep them secured in flight. * **Tortoise syndrome**: Maybe your mecha are less sophisticated than you think. To enhance running and jumping, the limbs have limited functionality. If the thing is knocked over onto it's back, it can't get up on it's own (too much armor and weight). These are actually armatures to hoist the bot up to where it can stand up on it's own. * **Shock absorbers**: On a similar note, the poorly designed head or body is vulnerable to crushing if the mecha is thrown or dropped. These armatures are like huge shock absorbers that point up or back to absorb body impacts, while down and forward are covered by the legs and arms. * **Optical targeting arms**: The modern battlefield has so much EM interference that conventional radar and satellite targeting systems are useless. Even laser scopes have that new (insert gizmo here) that stops them from being useful. Optical sensors mounted out on these extensions allow long-range targeting with depth perception. They are movable to adjust to conditions or shelter behind the body when not in use to prevent damage. [Answer] The fins behind mecha are [molten salt](https://en.wikipedia.org/wiki/Molten-salt_battery) heat sinks. Firing directed-energy weapons repeatedly produces a lot of residual heat, unless a superconductor is being used to transfer energy. To dump this heat *quickly*, you need massive radiator panels. Instead, the solution is to run a molten salt-based cooling system throughout the mecha, which strips excess heat away from the guns and pumps it into heat sinks so that it can be disposed of over time, rather than all at once. This means that you don't need massive radiator fins. The fins are behind the mecha to avoid getting shot. They're long and wing-shaped because, while their core is a heat sink, their surface is a radiator designed to slowly dump heat from that heat sink. They're outside the mecha because it gives more internal volume inside the mecha for components, and more surface area outside it for the radiator. They're also outside the mecha in case they get hit; high-temperature salts dripping through the insides of a mecha would massively compound any damage sustained. They're *also* outside the mecha in case they need to be ejected, since they might overheat if the radiator panels are damaged or covered in some kind of substance that reduces their heat-exchanging capabilities. They're **also** outside the mecha in case they need to be repaired, since reaching into the guts of the thing is harder than working on an external component. They're ***also*** outside the mecha so that they can be [hot swapped](https://en.wikipedia.org/wiki/Hot_swapping) out for fresh packs that haven't been saturated with heat energy yet without having to open up any paneling. [Answer] I can't resist pointing out that there is a historical parallel of a powerful military unit having mysterious wings for no obvious purpose. I am speaking of the Polish winged hussars. According to Wikipedia: > > The Polish hussars were renowned for their huge "wings", a wooden > frame carrying eagle, ostrich, swan or goose feathers. In the 16th > century, characteristic painted wings or winged claws began to appear > on cavalry shields. The most common theory is that the hussars wore > the wings because they made a loud, clattering noise which made it > seem like the cavalry was much larger than in reality and frightened > the enemy's horses; however, such sounds would be impossible to hear > in battle. The wings (or wing) was mostly used to block the back of > the rider from swords or protect them from getting thrown off their > horse. > > > I am not sure the horse theory is relevant to the robot example. The noise theory could correspond to some sort of antenna or scrambling device, which has been suggested by other posters. The "block the back of the rider from swords" theory makes sense to me. If the robots' heads are as delicate as ours, then it makes sense that you'd want to protect them as much as possible (perhaps not from swords, but from falling debris etc. (although why you'd put all the most fragile stuff in the head, I don't know)) [Answer] **Patent avoidance.** The companies that patented mech arm designs didn't consider having nearly useless counterweights and didn't draw them in their preferred embodiments, resulting in a loophole that an overly cosy judge in some district favoured by patent litigators allowed. Engineers have come to like them, as hitherto the idea of useless space was absolute design heresy, resulting in many late nights and redesigns whenever marketing or corporate HQ asked for a last minute feature. Forgot to allow for a sufficiently larger auxiliary fission battery? In the wings! Corporate HQ wants to make sure that noone flies faster than Mach 7? The speed module goes in the wings! In companies that value their mech pilots, the right hand wing is often reserved for pilots to carry personal cargo. Naturally, such systems are not resistant to neutron bombardment and so there's no way they are going in the torso. The only downside is having to read reviews of one's mech in Mech Magazine where they gloss over having a 16 GW fusion annhilator beam as well as total mass clocking in under 15T, but it losing 2 stars out of 5 because of an "*uninspiring set of wings*" that "*doesn't match the sensibilities of the 2370 A.D. consumer*". [Answer] 1. **Reinforced phased array receivers/emitters** for threat detection designed to give 360 degree coverage for the detection of incoming high velocity threats. In order to provide maximum coverage they have to be mounted as high as possible on the chassis while not getting in the way so the top of the back is the best compromise location. And while one 'wing' would do the job engineers soon discovered that the system worked best with two emitter/receivers working in tandem as this improved accuracy significantly enough to be worth the extra cost/weight. (Two separate systems spaced even slightly apart lets you use trigonometry to get a better fix on a target.) Plus it adds redundancy. 2. **Threat interception pods.** Spaced along the leading and trailing edge of each wing behind hinged panels are a number of compact threat interception modules each containing a small number (2,3,4)? of short range countermeasures tied to the threat detection system and designed to be fired automatically at a threat just before impact. The defense system is directly linked to the detector which, once turned on actives autonomously from other systems onboard the robot. In effect this makes the the 'wings' almost like a second (dumb) robot mounted on the back of the first. This lets the robot focus on other aspects of the battle while the wings do the work of detecting/stopping incoming threats. But importantly real time longer range imaging of the battlefield is also fed continuously to the robot which can then focus the arrays if it chooses to on particular points of interest for a better 'look' at whats going at that location. However doing so for any length of time is however 'risky'. This is because it reduces the radars/lidars coverage of other parts of the battlefield and also reduces the system's ability to detect incoming threats. So if done it's done for short periods of time only. (Bit like sticking your head over a parapet to get a better look at who is shooting at you! Yes you can do it but you don't want to stand there gawping.) 3. **EM Weapon mount** although the two main uses of the system are described above if the opportunity arises the phased array emitters can be focused for short periods of time on sensitive targets and used to jam/blind/damage them by focusing high power EM onto/into them. (Again though this reduces coverage.) [Answer] Other than pure aesthetics, there can be some functional reason these robots have these appendages. **The best purpose of these is to help with in flight control.** 1. These can act as control surfaces. many modern airplanes have many control surfaces to assist with control and maneuvering at high speeds. 2. They can also contain small thrusters to help in vector control, mostly for control outside of an atmosphere where aerodynamics will not work. 3. Last on control, these can, at least, provide a means of counter balance. These mechas are not very streamlined and not very functional in flight. to counteract the motion of something as an arm or leg in flight, can cause the mecha to get taken off balance. these can act to counter such imbalances. The weight of an arm could be around 10% of the whole weight of the machine, not counting any weapons mounted to it. That much weight shifting in flight can cause extreme disruptions. Big picture, these mechas are not truly built for flight. Its a purely aesthetic choice to have a humanoid like body plan. To make them functional in flight, you have to make design considerations to keep them functional with your fashion choices. **Auxiliary functions** 1. These mechas use a lot of power and produce a lot of heat. you cannot have the heat sink close to the main body of the machine, or else the operator will get toasty. Having an external component to allow airflow across them will keep the macha cool. 2. These can carry modular accessories that can be changed out based on the mission it is being sent on. These "wings" can be surface to fit varying sized devices from a suite of sensors, extra armaments' to extra storage space for a camping trip. 3. the ability to change the RADAR cross section at will. Due to it being a humanoid shape, its not going to be stealthy. Might as well use this to your advantage. A highly articulated "wings" can be shaped to simulate a Cessna, a small jet fighter or what ever shape you want the RADAR operator to think you are. 4. Damage mitigation. These can act as extra armor or shielding, or be sacrificial material to take damage rather than the core body. Placed on the back can protect the mechas blind spots from damage. I have seen many anime, such as Macros, Gundam, Exosquad, etc. All these options have been used throughout them. [Answer] ### They could contain cameras that can look around corners. In the anime series Appleseed, whose mechs and cyborgs have similar sorts of fins, these sort of back-mounted fins mount cameras in the ends that allow the operator to look around corners when breaching buildings, without exposing vital portions of themselves to enemy fire. Here's a video of them being used this way, in a clip from the 2004 movie: <https://youtu.be/dJEvkKuMzqE?t=292> Killmonger mentioned that he liked anime, and the first Iron Man movie was released in 2008, so it's possible in-universe that he drew inspiration for them from this movie specifically, even. [Answer] In Gundam, MuvLuv and Full Metal Panic franchise the wings have multiple purposes, some of them are heat sinks used to cool vital components. Others act as stabilizers to help the robots maintain balance when they move, or they contain stabilizer or orientation jets that can be used when in flight/to act as jump jets. Some of this is take from real life where heavy construction equipment will have protrusions from rear of movable component that act as a counterbalance In the Gundam Wing universe , several models of Gundam has their wings as shields. For example, in Eternal WAltz the lead Gundam wraps its wings around itself to act as a heat shield from beam weapons and for rapid orbital reentry, while Duo Maxwell's Gundam has wing like structures that wrap around itself to act as radar dampeners. [Answer] Even if wings don't have enough lift to fly, they can still 'push' against the air for steering and stability. Like Velociraptors. [](https://i.stack.imgur.com/fMHiy.png) [Answer] **Mountings for drop-tanks** Mecha have very limited internal space. That much should be pretty self-evident. So much so that fuel and power is often a recurring plot-point in shows featuring them. The Evangelion for example was physically tethered to a nuclear reactor and could only operate for a few minutes on battery power. So, to facilitate longer operating times, most mecha mount droppable fuel-tanks on fins on their backs. The fins themselves can fold away when not needed, but extend out to release the empty tanks and reload with new ones. It's useful to drop them rather than simply refill because the switchout is much much faster than pumping fuel into onboard tanks. This same system can also be used for a variety of other liquid and gas resources, such as Coolant, Hydraulic-fluid and even onboard air supplies in hazardous environments. The upshot is that most mecha benefit enormously from having the capacity to rapidly restock their consumables in the field. The actual racks of consumables are housed on the back of the mecha to keep them out of the way and protect them. As well as to share mountings with backpack upgrades, and to link to docking facilities better. [Answer] We all have seen how these amazing robots jump and reach the enemy real fast for close combat one-on-one action. There is where I find it useful, since those little wings are meant to control the body of the robot at those gigantic speeds! Also, makes it difficult for other robots to apply some krav-maga style killer grab, punch or kick from behind, so is useful as a mano a mano fight shield too. ]

[Question] [ In my novel, there is money to made in the capturing and selling of 'exotic' animals from a distant, jungle-covered continent, though for various reasons (notably that it is illegal under Roman rule) buyers often like to keep their purchases and contacts secret. So they hire pirates who sail to these strange lands and capture the unusual animals found there. However, often these animals can be quite enormous (e.g T-rex like creatures, giant anacondas etc) and dangerous. Obviously the hunters would have to have some kind of tranquilizing methods consistent with a voyage at sea taking potentially days. Issues would include how to get the animal on board, how and where too keep the animal, how to keep it sedated, methods for preventing disaster if sedation failed, and importantly, how to keep it alive. Any thoughts or suggestions would be welcome! [Answer] **In eggs** As in, a fertile dinosaur egg, not the adult. Moving livestock is always tricky, even more so when said livestock is composed of strong and dangerous creatures, which have a tendency to die easily in the wrong temperature, thanks to the fact that they're cold-blooded. If pirates wanted to smuggle these creatures from their distant territories back to these lands, they'd kill the parents and steal the eggs (or just steal the eggs and run like crazy), then ferry the eggs back, and sell them for a tidy profit. Of course, you'd have to prove that it's a bona fide dino egg, so perhaps the pirates would let them hatch into baby dinos on the far side of the ocean, but the easiest way to smuggle a massive T-rex is to just steal a T-rex egg and take it across the ocean like that. [Answer] There are a number of questions here, let's take them one at a time. # How to capture / sedate the animal, and keep it alive? Through its food, what the pirates need is some plant or drug that will keep the animal unconscious. This should be used in it's capture, just prepare a big pile of meat or other food with some of the knockout plant inside. The animal eats it, then falls unconscious. The pirates will need to periodically feed/drug the animal during transit. This can be accomplished with a feeding tube and a way to grind up the food and knockout plant. # How to get the animal on board? You don't put it on board the ship, rather on a floating barge specifically designed for that purpose. The barge will be towed by the ship. With effort (or beasts of burden) the same barge can be dragged across land to load the beasts, then to a beach suitable for launching the barge. # Where to keep the animal? It remains lashed down on the barge for the entire trip. # How to prevent disaster? Provided the animal cannot swim faster than they can sail their ship, all they need to do is cut the tow line to the barge and leave. The longer the line the more safe they'll be. [Answer] **Arr, sail north.** Some modern lizards hibernate when it gets cold. On the other hand, evidence seems to suggest that dinosaurs probably didn't hibernate. It may be within the scope of your readers' suspension of disbelief to just accept this in the context of your book about dinosaur-smuggling pirates. [Answer] **Feed it so it sleeps.** * Obviously the hunters would have to have some kind of tranquilizing methods consistent with a voyage at sea taking potentially days. Many reptiles enter into a long period of inactivity after gorging themselves. * Issues would include how to get the animal onboard: Place bait trail and after it crosses the ramp, lift it. Maybe the animal can't swim and won't leave the ship from fear of drowning. * How and where to keep the animal Get a whole ship for it, place ropes or chains and drag it. So there is no fear of TRex munching the crew. * how to keep it sedated, methods for preventing disaster if sedation failed Count on placing a bunch of herbs inside the guts of a dead cow. T. Rex eats the cow and besides falling into the common hibernation, you will also get the bonus of the sedatives. * importantly, how to keep it alive. You will lose some to dehydration/drowning/storms. As long as you get a HIGH sum to make it worthwhile, your pirates won't care. [Answer] Transport Juveniles. A fully grown adult dinosaur would require an independent barge as other answers have suggested. An adult dinosaur would need to be kept sedated through their food or water. In addition, they would require significant care to ensure it's survival in their sedated state and protection from the elements while at sea. It would become easier if you are transporting juveniles instead. They can be kept in iron cages on the main ship instead. They would require less food and management than an adult. [Answer] As a pirate, I know I'm going to need a large ship. It's going to be so ridiculously large, I have no doubt Caesar will outlaw such craft to prevent the smuggle of dinosaurs. So I can't keep it in Rome, or the Mediterranean at all. I'll have to store her in Gaul, where the Empire's influence is weaker. I shall then sail directly to the new world. Once there, I will incapacitate the creatures with venom derived from snakes. Hauling these beasts onto my ship will be difficult, but they are valuable enough to keep enough hands on board to do the job. I'll store them in the center of my massive ship, chained up, periodically injecting them below the midsection with a paralyzing agent (also derived from snake venom) to prevent their thrashing about. I will then sail due North, making landfall every night, heading as close to the ice as I dare. When I approach [modern day Greenland], I shall stock up on supplies to feed the beast for the voyage East to Britannia. Landing in Britannia, I shall again stock up on supplies to sail the relatively short distance to Gaul. I shall off-load the beast there, and make the journey on foot into the Empire. Larger beasts will not eat me or my crew, provided they are well fed, humans are too small to be worth the effort. Mid-sized beasts may very well make the attempt, so it is best to keep them heavily sedated. The long necked beasts are worth the effort only once a season, as they fetch a fine price, but can only be taken one at a time. [Answer] **À la Gulliver's?** In Jonathan Swift's novel, when Gulliver travels to Lilliput, he finds himself tied down and held by several ropes onto the land. A dinosaur could have been sedated and tied on top of a structure, that would later be used as a raft? The raft then would be towed by ships, which would keep the crew safe, short of the chosen sailors who have to go check on the creature once in a while. [Answer] Assume they are cold-blooded. Cold-blooded reptiles are [poikilotherms](https://en.wikipedia.org/wiki/Poikilotherm) and torpid if not exposed to a source of heat. They need to bask in sunshine or sit in a warm place in order to raise their body temperature. You can play around with a cold gators mouth and it won't do more than give you an angry stare. So, if you assume that the dinosaurs were cold-blooded (which they apparently weren't) then the problem amounts to keeping them cool, say in the ships hold, refrigerated with some salted ice. If Hannibal managed to get [voracious](https://www.nytimes.com/1984/09/18/science/the-mystery-of-hannibal-s-elephants.html) elephants to Italy from northern Africa, then bringing over a few dinos should be a breeze. ]

[Question] [ I am well aware that this question is on the border between the Worldbuilding and the [Sci-Fi](https://scifi.stackexchange.com/) site. I decided to post it here, because I am seeking for a general society/worldbuilding answer and "Vulcans" are used here to help you paint the picture: Imagine a humanoid race which starts its "sapient" era in a constant [ADHD](https://en.wikipedia.org/wiki/Attention_deficit_hyperactivity_disorder) frame of mind. They find a solution by creating a society which fights these symptoms via excessive meditation and emphasis on pure logic. And this race does very well. They evolve into a space faring civilization, even mastering faster-than-light travel. It appears logical (pun intended) to me that, somewhere during this evolution process, they have to discover some sort of cure which helps them to get to the same frame of mind that long meditation sessions and/or other mind exercises put them in. Even if it means taking a pill every 8 hours (assuming a 24 hour cycle on their planet and average need to sleep of 8 hours), this pill is still more convenient and, moreover, more logical to take than just continuing the mind exercises. **So, why do they decide not to take the pill?** Again, please note that Star Trek [Vulcans](https://en.wikipedia.org/wiki/Vulcan_(Star_Trek)) are used just for example only and a solution does not have to be the from Star Trek universe. [Answer] ## Traditional and cultural values It may seem odd for a deeply logical society to hang on on tradition, but they may deem it logical to preserve their history and rituals so not to lose it, and to learn from the past. Another aspect may be that it is a passage from youth to adult to master the meditation ritual and controlling your own emotions through self-control and hard work. ## They do not like to be dependent Another point to consider: Imagine the next generation of your "Vulcans": Never learned how to meditate and control their emotions with that method, and are now dependent on the pill. And now throw a sudden scarcity of that pill in the equation. The result can vary as you like, from sudden depression, anger bursts, riots,... And to turn this up to eleven, imagine a war, where the enemy blows up the pill factory at the start to gain a tactical advantage. [Answer] # Meditation has other (positive) side effects Meditation is good for you! The positive side effects of relaxation techniques are not marginal, [as they are for humans](https://www.nbcnews.com/better/health/forget-what-you-ve-heard-being-cat-lady-healthy-ncna789676), they are very significant. Something about the Vulcan evolutionary heritage predisposes them to short, passionate lives. Meditation instead helps to change long term biochemistry. Chemical processes that *cause* the short attention spans, also cause shortened lives. Meditation not only ameliorates the short attention span, but it also extends the life ([Sarek](http://memory-alpha.wikia.com/wiki/Sarek) lived to 203). Pills have been developed that helped Vulcans to keep their attention, but they did nothing for the life span. So you could take pills and die of old age at 80, or you could meditate and live to age 200, along with all your friends. Such a wide discrepancy in life expectancy would easily explain why no one is interested in pills. # The pill has negative side effects On the other hand, the pill might be the one causing negative side effects. The complex biochemical manipulations required for the pill to take effect are hard to replicate with a single pill administered orally. There may be some [side effects](https://en.wikipedia.org/wiki/Olestra#Side_effects). Taking a page out of current scares, some complex molecules can have far reaching biological effects. If, for example, the pill [causes infertility](https://factor.niehs.nih.gov/2011/april/science-infertility/index.cfm), that would be a pretty good reason for the government to ban it. [Answer] **Real-life answer here:** It turns out that actually eliminating emotion, as opposed to its expression, is counter productive. People with brain damage affecting specific areas of the brain (such as myself) are unable to experience emotion, even though they retain all other faculties. My problem solving ability is in the 98th percentile as of my last testing, even though my emotional response is next to zero. The side effects are reduced ability to encode new memories, inability to prioritize or make decisions, inability to stay focused on a task, inability to recognize or respond to normal social cues, and inability to recognize that they are irritated until they flip into the fight or flight survival mode (to an outside observer they go from passive to all out rage in under a second under certain types of stress). While we like to think we make decisions rationally, there is a growing body of medical literature that appears to point out that we make decisions almost 100% based on emotion, and then apply conscious reasoning to our decisions after the fact. As we see with Vulcans, over the evolution of the Star Trek universe, they went from being portrayed as emotionless to being highly emotional but also highly disciplined. The vulcan word translated as "Logic" in star trek vulcan/english should more properly have been translated as "discipline". [Answer] Just to add to [Darthdonut's answer](https://worldbuilding.stackexchange.com/questions/125573/why-dont-vulcans-just-take-the-pills/125575#125575) which is very good. Taking a pill instead of meditating would save perhaps an hour or two per day per "Vulcan"... but there may be other problems. ## Production Chain But then you need to produce enough raw materials which would take a lot of workers worldwide to produce, you then need to refine those materials into the drug, requiring more workers and resources, which then needs to be transported around the world, needing more resources and workers. and that's before you start putting people into space where producing the drug might be difficult and storing might take up a lot of space for long duration missions. (i'm intentionally leaving replicators out here!) *Going to all that effort to produce something that people can solve themselves by a little bit of meditating seems pretty **ILLOGICAL** to me* ## Resistance Then consider that there is not a single 1 size fits all ADHD drug (or most drugs), some drugs work for the majority of people but there will always be those that either have diminishing returns on the drugs effectiveness of their lifetime of use, or they are resistant to the drug from the beginning, do you leave those people behind? ## Save time for... This very logical species... would be unlikely to produce much in the way of film or video games, as those practices are not a logical use of your time. but time not working is important for the health of the people, so what are they going to do with their time that has been saved by taking the pill? ## Side Effects To my knowledge, other that the potential for a number backside or maybe back ache from sitting incorrectly Meditation has not negative side effects, however drugs can have a number of side effects. [Answer] ## Taking the pill means to admit mental weakness The vulcan society values people based on their capability for logical thinking. The most logical people are the most respected ones. But if you can not attain a logical mindstate free of emotions by yourself, you are a fraud. You do not deserve to be on top of society. The human equivalent would be an athlet who is using doping. When you needed to take drugs in order to win, you do not deserve that gold medal. Now why would a logical society care about this at all? The logical way to judge efficiency is to look at the results, not at how they were accomplished. A possible reason could be eugenics. You only want people with superior genetics to procreate. So it is important that everyone is able to judge the logic of other people in a natural state and only mate with those people who are the most logical. ## The pill only gives you a temporary boost, but meditation makes you smarter in the long run The pill might help a Vulcan to concentrate better for a short amount of time, but it doesn't improve one's cognitive abilities in the long run. Regular meditation and mind exercise, on the other hand, lead to a permanent improvement. A vulcan who meditates for a few hours every day will become more and more intelligent over time. Taking the pill, on the other hand, won't have that training effect. Even worse: Being under the influence of the pill might interfere with the ability to train one's mind through mental exercise. So when they take the pill, they fall behind in their mental training. A further way to nerf the pill could be to assume the Vulcans build up a tolerance for the drug over time. When they use the pill a lot, then they will need larger and larger doeses for smaller and smaller effects. Eventually it won't have any positive effect at all. That means some Vulcans might take the pill in an emergency when they need a temporary intelligence boost, but they will avoid taking it over prolonged periods of time. [Answer] ## **Because the pill is a quick fix that doesn't really achieve the goal** A frame of mind isn't simply a chemical state (or, the kind of mindstate they wish to cultivate goes beyond simply calmness/lack of emotion, and involves among other things a high degree of self-knowledge, the assimilation of particular values and worldview, and facility with advanced psychological techniques). Therefore, it can't simply be induced by a blunt instrument such as medication. It requires education and a degree of life experience, as well as a long period of self-cultivation and practise, to become adept at cultivating this mindstate. Although particular neurochemical signatures/blood chemicals/brainwave patterns are an outward sign of having achieved the necessary self-mastery, they are not the same so they do not consider it enough to induce them by chemical means. Additionally, part of the process of self-cultivation could involve habituation against "shortcuts" and "taking the easy route", so they could have judged that it is worth spending years practising meditative techniques for the attendant self-discipline, even if pills exist that would appear to give the same or similar results more quickly. [Answer] ## It is dangerous with long-term use While this pill may solve the problem perfectly in the short term, long term use is dangerous as it triggers conditions such as early onset dementia. Turns out meditation really is better than medication. [Answer] The pill is used in extreme situations (eg. combat) and sometimes recreationally, so it's not completely "banned" but the immense fear of not being able to live without it would be enough. [this fear being reasonable bc the pill requires a costly imported resource] Also consider that the pill maybe has side effects with long-term use (psychological problems etc.) AND constant pill-taking IS a heavy addiction which would be a heavy argument in a logical society. Also give the meditation some other benefit. Maybe boosted creativity / free thinking, thins which only come when you actually sit down and meditate. Another point could be that their body only needs like 4 hours of sleep, and only the brain needs 8 to regenerate. Here meditation could count as "half sleep" meaning you could reduce your sleep cycle to 4 hours at night + meditation (during which you can still think about stuff or so). Just some random points, any combination of which would make a reasonable cause. Pick the ones that fit your world/story [Answer] The "Vulcan" pills, which their parents and doctors think of as "calming down" their child, are actually a depressant. So yes, they are calmer, yes they can focus better on a task, but they are also less creative, having less fun, and more bored. That "Attention Deficit" is actually a fast and curious mind switching gears to take in something new, a "breadth versus depth" approach to life: They see everything, extract the novelty of it quickly, get bored with the mundane details and their attention moves on to the next thing that offers some **novelty.** That "Hyperactivity" goes with it, that is **action**, play, having fun, trying to eliminate boredom. Attention Deficit and Hyperactivity only become a Disorder when it comes to gaining a DEEP understanding of subjects and FINISHING things. But unfettered, the intense focus on novelty seeking can actually be channeled into creative thinking and invention: The ***creation*** of novelty. Of course novelty is best created by people that have put in the hours to deeply understand a topic (mathematics, physics, biology, medicine, investing, law, engineering, etc). So these two opposite mind states can be complementary: The pill lets you put in the work. Going off the pill lets you see work in a new light and be creative about it. Back on the pill, you can turn that creativity into something you finish. Of course you can substitute meditation for medication, but it isn't as quick or as effective. On the other hand, if the pill (like some medications) builds up in your system and takes weeks to biologically eliminate, then people that need to be creative on a long term basis might forgo the pill altogether after their education is complete, and then rely solely on meditation, or form partnerships with others that ARE on the pill and can take the creative thinking and run with it. Kind of like the partnership of Steve Jobs (an idea man) and Steve Wozniak (an engineer and programmer) in Apple. [Answer] > > It appears logical (pun intended) to me, that somewhere during this evolution process, they have to discover some sort of cure which helps them to get to the same frame of mind as with long meditation sessions and/or other mind exercises. > > > Your assumption is highly illogical. On what grounds do you make the assumption that they "have to" discover a cure in the form of a pill? As a writer, did you write into their character weaknesses "Has undesirable behaviors which can be solved by pills?" Are we so certain of our modern ability to solve things by popping pills that we assume all problems have to be solvable that way? Of course you're not taking it to such extremes. But I wanted to point out that the assumption that you can just "take a pill and be better in the morning" isn't necessarily well founded. Indeed, it can be a question. Questions tend to spawn far more interesting world-building material. We actually don't know what happens at an electrochemical level during meditation. **In fact, if we take a step back, we don't even have an agreement as to what meditation actually is!** There are many behaviors people do, and they all get lumped into the word "meditation." It's surprisingly imprecise, for such a useful concept. Their particular meditation simply may not be conducive to pill popping. 100% of medicines have side effects. And, in this case, I'm not rounding up a 99.999% to 100%. It is a 100%. It's almost a definition. Everything that touches the body has some side effects, medicine or not. Oxygen has side effects. Did you know that the oxygen in your lungs is actually corroding the insides of your aveoli as we speak? Fortunately, our body has been doing this for a long time, so it keeps up with repairing the damage. However, divers breathing Nitrox have to pay attention to this. Dive with extra oxygenated air too deep, and the partial pressure of oxygen rises until it corrodes your lungs permanently and oxygen toxicity ensues (yes, the phrase is "oxygen toxicity") In our society, there are many drugs whose side effects are brutal. Then there are drugs where the side effects are downright benign. Some of them are so benign that we can't even identify their side effects. In our world, we find the medications for things like ADHD are benign enough that we can proscribe them to people with the relative abandon that's associated with the phrase "just pop a pill." But what about the Vulcans? Their ADHD may be more complex to cure. Their ADHD might have more side effects. Also note that logic has a tendency to amplify some side effects. If this is a highly logical species, any small tweak to the logical parts of their brain could have sweeping effects on their life. Indeed we can see an excellent example in the movie A Beautiful Mind. (spoilers are minor, but still protected by a spoiler tag) > > The medications given to Nash have a *tremendous* effect on his work. While others might have used the pills without an issue, they have a tremendous impact on him. In a very emotional scene, he convinces those around him that he needs to get off the pill and began a long arduous climb to find a way to overcome his disease without the pill. > > > On a related note, while you mention that the Vulcans were creatures who valued "pure logic," when you dig far enough into the concept of logic, you quickly find that there *must* be more to life than pure logic. If that little something in the Vulcan life is small and fragile, a pill might severely damage it. [Answer] After some consideration I have realized that **you can't**. Within the constraints you've given us, you can't make this all-the-way plausible without a lot of extra work. Bear with me here because I know that's an unpleasant result. You are phrasing this as a **fixable biological problem**. But you also have this race slowly becoming space-faring in an organic, natural way. Way before a race becomes truly space-faring (as opposed to our level of flinging tin cans around our star), they must have had tons of time with which to conquer genetic engineering -- we're talking thousands of years of practice messing with their own biology. We would therefore expect that they are biologically the best versions of themselves. Like supposing the fixable biological problem is "they're like humans with a way, way overactive testosterone production" -- well, they will presumably have found ways to engineer their DNA to reduce "testosterone production," whatever that means analogously to their biology. If they can do it with a pill then they can do it with a set of proteins. If the pill had side-effects they would have developed a mechanism that doesn't. Your options would therefore seem to be: # 1. They are newcomers to technology They didn't become space-faring in a slow organic process. Some spaceship crash-landed on their home planet and they were able to reverse-engineer the warp drives but they are still technologically very backwards. They haven't figured out the genetic engineering yet. This one is hard to arrange because often you need some technical know-how in order to reverse-engineer technology. If you can imagine dropping a train into the middle of 1000 BC, could its discoverers really figure out what it does? Would their metalworking be good enough? The same applies if we're analyzing some alien's technology trying to use it to learn space flight. But you might be able to make it work with a sort of "pirate race" that just conquers others' spacecraft, and those pirates might indeed be Vulcan-ish -- heck maybe that's why they don't respect property laws; maybe those laws seem "illogical" to them. # 2. The problem is not biologically fixable. It might be that the problem is not biological. Maybe it's cultural, having to do with how they're raised. This species might have a strange social structure where all the children have to raise themselves together in a group without adult interaction. In the process they do not develop any innate discipline. Medication is only reserved for those children who cannot learn to cope with adult life after they start to interact with other adults and learn how to focus. Or maybe it *is* biological, but it can't be fixed that way -- maybe their brains are wired with something other than neurons, call them Branch Fibers. The idea is that Branch Fibers can *only* work in a scattered way, so to apply those biological "cures" would not improve their focus--it would just make them think slower and slower until they stop. The process of totally re-engineering a brain for better scientific progress might be a longstanding open problem. There are a lot of options here but they amount to the idea that *a pill couldn't solve the problem in the first place*. And you said it *could* so let's cut these options short. # 3. It's not a problem. In this case, the situation is not viewed as a problem in the first place. Like yes, children are scattered and unfocused and yes they need to learn how to focus, but that's a good thing--why would you want to change that? Some of this is kind of like the previous one. For example if you think about the strange sorts of social structures that have evolved -- honeybees, wolf packs, anthills, human society -- it's not out of the question that maybe the biological "problem" has nothing to do with some hormone that's out of balance, but it's just how the species is biologically wired to raise its youth. But some of it is more fundamental. So I come from a physics background so let me explain with a physics analogy. We don't normally talk about our scientists this way or advertise them this way, but one way to imagine, say, the achievements of Albert Einstein is that he got *radically pissed off*, that genius is 1% inspiration, 49% perspiration, and 50% aggravation. To eliminate that "negative" aspect in reality might doom us to never making revolutionary scientific progress. And I'm not saying that Albert ever *showed those emotions* to others, it's not a part of the historical record as far as I know, but you might imagine that that this is what was alive in him. Let me clarify. Everyone who comes to a cliff they can't climb takes the downhill road away. You have to. Most such people then see "ooh there's a river down there, that leads to a lake," and so forth -- they find something else. But you have to get really pissed off at that cliff to keep returning to it week after week trying new strategies to get the heck up it. For Einstein at least in four of his major contributions (special relativity, general relativity, the equations to figure out Avogadro's number, and the EPR experiment) there is a common theme where the laws of physics said "there are two or more totally different physical mechanisms at play here, *and you can't figure out which one is responsible*." That sort of thing apparently *bugged* Einstein so much that he kept returning and returning to those things, making mathematical models even though he stunk at math, just trying to break those systems. In the first case he was like "ARRGH what if reality just DOESN'T KNOW who's moving?!" and in the second case he was like "ARRGH what if NOTHING IS EVER REALLY FALLING?!" and in the third case he was like "AHA I FOUND IT SUCKERS, if we take Boltzmann's mathematics really seriously then the atoms that are too small to see could STILL induce a JITTER in the particles that we CAN see" and in the fourth case he was like "AHA I FOUND IT SUCKERS, my previous relativity theory says things need to be LOCAL and the LOCAL hidden variables theory predicts something DIFFERENT." Of course he didn't say any of it like that, but I like to imagine that's what went on in his head. :-) Similarly you might imagine that this ADHD scatter-brainedness has some sort of *real purpose* to these Vulcans such that they would never *dream* that you would want to get rid of it. * Maybe it is absolutely necessary to compete in a set of games that they like to play recreationally. * Maybe it is part of how they experience creativity. * Maybe their language does not allow them to refer specifically to a thing in itself but is based on *circumlocution*, so they always have to ambiguously describe the thing they're talking about rather than just specifying it by name -- and maybe that requires a lot of free-association neurons to both speak and understand; fixing the biological problem would render you mute. * Maybe they have a periodic biological urge to seek some sort of isolation in the wilderness away from the rest of their society where they suddenly find clarity on their life purpose, and these mark the various stages of life -- a kid who never had his/her first Calling would never have grown up. "You want to freeze a person in an adolescent brain stage while their body ages? Are you *out of your mind*?!" But for whatever reason nobody thinks it's a *problem* that their brains are naturally ADHD-inclined, they just think that focus is a *simple learnable skill* that needs to be taught to every third-grader. [Answer] My idea somewhat mirrors the ideas of others, as this is basically a "the pills have a side-effect" answer... However... taking the pills makes their core racial traits (logical thinking) weaker over time, as these traits are / were a direct result of said ADHD frame of mind and their natural ways to deal with this issue. These traits are valued in their society and are, after all, what got them their space ships and advanced FTL drives... In other words - taking a pill once? Not a problem. But stuffing everyone full of those pills over a prolonged time (especially minors) yields very undesirable results, as individuals become increasingly emotional and irrational, and this just isn't logical. [Answer] ## If everyone has it is it really a detriment? Humans, we have these things called [gallbladder](https://en.wikipedia.org/wiki/Gallbladder) which are useful in some cases but can be removed with almost no ill effect. So why does not everyone remove it like with [wisdom teeth](https://en.wikipedia.org/wiki/Wisdom_tooth). Easy, there is just no point to it. It is a common point that everyone has their Gallbladder. The same goes for you Vulcans, they don't treat their [ADHD](https://en.wikipedia.org/wiki/Attention_deficit_hyperactivity_disorder) like symptoms because it is common between all citizens. Their culture would take this supposed deficit and account for it because everyone has it. ## Is ADHD even a detriment to humans? It is thought that [ADHD was a genetic trait that was beneficial to hunter gatherers about 10,000 years ago](http://evolution.binghamton.edu/evos/wp-content/uploads/2012/02/eisenberg-and-campbell-2011-the-evolution-of-ADHD-artice-in-SF-Medicine.pdf). It could also be thought that soldiers throughout history would find the hyper attention is useful in battle to understanding what is going on. That is why we still have this trait in humans. So the vulcans, with a society built around it could keep it and try to focus this attention. I could imagine them being very good pilots, soldiers and anything else that needs fast reaction time. They may even hire or select based on the level of ADHD that they posses. **So no, you would not want medication for ADHD in your vulcan culture as it is a beneficial part of who they are.** [Answer] The supression of emotions by artificial means defeats the purpose of supression in the first place. Vulcan's logic was a pacifistic idea to curb their war-like emotions. It's been implied in Star Trek that a pissed off Vulcan is worse than a really pissed off human. The search for less killing found a large audience to the idea of pascifism and disciplined approach would be better as you are not dependent on anyone but your self for an action. As someone who does have ADHD and does take medication for it, I can say that if there was a reliable method to meditate it away, it would be better. The stimulant medications actually can make ADHD symptoms worse when you're suddenly without them. If I do not have my prescription filled before I run out. This is because your body will build up a natural tolerance of the stimulant... and it doesn't go away when you suddenly come off the pills. This tolerance manifests as a depressant to counteract the the stimulant... essentially your body pumps the breaks around the time of day you would take your medication... but your body doesn't know today you aren't taking pills, so it pumps the breaks at the same rate... but without the stimulation, this results in a withdraw that would actually make the symptoms worse. Assuming the Vulcans could control this hyper-emotional state with either pills or meditation, the meditation would be preferable because you are never without it and can natuarally control yourself with self discipline. There will be days where you're going to forget to take the pills... or stranded in the wilderness because some Scottsman was drinking Scotch on the job and now the Transporters are down, or some god-like alien has decided he is going to use his phenomenal comsic powers to make all the senior bridge officers play Robin Hood... and hoping no one notices this is just like that time with the holodeck malfunction from two weeks ago. There will be times where you can't take your pills... but you can still self-discipline. Of course, real life this is not the case for ADHD people... and is why they are disqualified from military service in the U.S. [Answer] # Reliability What happens when you run out of pills while hitchhiking through the galaxy? If you know how to meditate, you don't need those pills anyway. It's more reliable to learn a skill than to depend on pills. # Biology Maybe they simply have very narrow throats and don't handle pill swallowing well. [Answer] > > It appears logical (pun intended) to me, that somewhere during this evolution process, they have to discover some sort of cure which helps them to get to the same frame of mind as with long meditation sessions and/or other mind exercises. > > > I agree, to us it seems like a logical thing. But perhaps the evolutionary history of your Vulcan analogues was radically different. (This is long - skip to the end for the punch line.) In the question you stated that the condition was present at the start of their sapient phase. In order for them to evolve past the hunter-gatherer societal stage they would have had to find a way to manage their mental state. Unless there's a convenient berry packed full of psychoactive chemicals that will do most of the work they are going to be stuck in that H-G lifestyle for a long, long time. That doesn't mean they're stupid, just that without mental control they are unlikely to achieve much in the way of advancement. They just can't sit still long enough. Unfortunately that makes them pretty terrible hunters. They can't lay in ambush for hours at a time, they have to rely on more aggressive hunting tactics. And when the game is scarce the tribe suffers. Until one day someone finds that eating a certain rare berry - poisonous in more than very small doses - lets them do something new. They can sit still and wait, without suffering, without having to react to every stimulus. This lets them hunt new prey that was impossible for them to hunt before. Unfortunately the toxins in the berry build up in their system and after a handful of hunts and they die. For a while they sacrifice themselves for the good of the tribe, hunting with the berry to give the tribe a survival advantage. A few try to emulate the state without the berry, but are scorned as lesser beings for not being willing to sacrifice themselves. And then the climate changes, killing off the berries and further reducing the available prey. Now the few who have been practising the slow hunt without the aid of the berries are the only ones able to provide protein for the tribe. Tribes that have no hunters capable of controlling their emotional state will die out, etc. The young people would be trained in the mental discipline as a matter of survival. The best would be taken to be hunters, but eventually every adult would have some facility with the discipline. And now the primitive people will have a chance to develop past simple H-G and start the long crawl toward true civilisation. There will be some falls, some setbacks, etc. Enough to give a history filled with examples of what happens when you fail to learn control. So by the time they're *capable* of creating a pill to control the emotions they have no need to do so. Hundreds of generations have practised and refined the mental discipline to the point where it is extremely effective. They retain all of their ability to innovate, they can release their conditioning when it makes sense to do so, etc. [Answer] **They are silicon based and therefore "pills" are considered illegal.** They developed somewhat normally but the planet that they live on is actually mechanical and not biological in the same sense we are familiar with. As a result, while their brains are still just as complex of a structure, they are not regulated by hormones as much as electrical impulses throughout the body. In other words, some more organic sense of circuitry. Pills therefore are not like we consider pills to be, at least psychologically affecting pills. "Pills" for this race and due to their advanced knowledge of their own physiology are actually like microchips that reprogram portions of the body for some period of time or indefinitely. So for instance, you have issues with stomach acid or digestion? You need that stomach regulating DLC pack! As a result many years before meditation was used to curb violence and wars various corporations and world leaders attempting to use pills to regulate mental illnesses as a front to product mind control chips. Effectively they learned to make computer viruses, and well... these aliens of yours are glorified naturally occurring androids. Needless to say, it didn't go well. So it is therefore logical to assume that not everyone believes in and accepts the tenants of logic entirely and worship the 0's and 1's of the universe. Therefore one cannot assume there is not malice in such things and it best to remain in complete control. You wouldn't let someone other than the manufacturer mess with your computer and reprogram it without you knowing exactly what they are doing with it would you? Well for this race, the only "manufacturer" conceivable would be a deity, and I don't think anyone is claiming a deity made these pills. Even if you want a biological race, it could just be that part of the reason the wars occurred and this all happened is because all of the race was in some way either forced or chose as a collective to transfer their consciousness into machine bodies that would function 100% identically to their original bodies (aside from increased durability and lifespan). So a point of practice, pills of that form are taboo as anyone could try to use them as a means of rising to a form of dictatorship. tl;dr If you can arbitrarily reprogram the brain, you never give anyone permission to do so. I claim this race is advanced enough that they can and therefore no one should be boldly given that power to do something no one should ever do. I just have to say because this is just something that occurred to me. It isn't really relevant to what I'm saying as a reasoning here but it is just a general comment towards what is and isn't "logical". Really from what I understand at least logic is effectively just assuming a set of statements to be true along with statements that say what it means to "prove" a statement (I believe these are objective but variants might exist) and then only accepting statements that are true as can be proven as true from the starting statements and only accepting what is false from what can be proven as such from the starting statements. Statements that cannot be proven as such are just unknown (or potentially having no truth value at all). The reason I say this is that logical behavior is then just only doing actions according to what logic would say is the best action or correct action or however you wish to phrase it. So therefore a system of logic that is alien might not have the same starting axioms we do. For instance if a system of logic that had reasonable looking axioms could prove that universal extinction was ideal, then your alien race would move towards that goal. In this situation it's just that basically the pills are considered not ideal according to that logic. Of course "that logic" is effectively what we as answers are providing by various hypothetical situations but in a more meta sense the truest answer of all is just this: > > Whatever axoims your race of pure logician aliens live by, the statement "These pills are a piece of shit and meditation is superior." is provable. > > > [Answer] # Bad reputation Everyone who works longer than 6 hours gets at least a half-hour meditation break. As it is possible to get rid of the unpleasantly paid break with this drug, the employers' associations were very interested in this drug. After a long lawsuit in which a large online department store tried to force its employees to take the drug, it became a synonym for the obsession of companies, to optimize their employees, which is why the majority of the population rejectes the pill. [Answer] # Their health insurance didn't cover that sort of thing While being a technologically advanced race, they still had some ingrained capitalist beliefs. This caused some issues with medical care and while technologically they had the pills available, they would cost thousands a month to actually take. Some nutter kept putting out videos on VulcanTube suggesting that meditation was the solution to all their ills, from the plague to cancer. Luckily it actually worked for this. [Answer] Vulcans don't take pills to control their primal nature because, so far as we're aware, there isn't one. Remembers, Vulcans are a completely different species with a biology and physiology all their own. Their blood isn't even red iron-based, it's green copper-based. Spock, the famous half-Human/half-Vulcan hybrid, had green blood and was sometimes seen to have very adverse reaction to certain Earth products (he once became intoxicated from a mint candy and passed out from a single breath of nitrous oxide) so giving them our medications would probably be a very bad idea. Also, the Vulcan philosophy of logic and suppression of emotion are at the core of their civilization for very important reasons. One, Vulcans are very spiritual. They believe that suppression of emotion is a source of not only inner strength but also self knowledge and enlightenment. Two, their basic nature is much too unstable to be controlled by something that can be taken away. The Vulcan species without their control is more violent and unstable than the worst Klingon; they nearly obliterated themselves and even their homeworld with longtime nuclear war back before the Time of Awakening. It goes beyond necessary for each one of them to discover and harness their own self-control continuously from an early age. ]

[Question] [ Is a gun which produces no sounds within the human range of hearing possible? I know of a couple issues: 1. Most bullets move quick enough to make a whistling sound, but I may be incorrect in that regard. 2. The bullet may grind against the barrel of the gun, creating a grinding sound one could hear. 3. The firing mechanism would most likely produce sound. Even something that used magnets to propel the bullet would have something keeping the bullet back, and that may grind against other metal in the gun. Constraints: Any sound produced must not be within the range of human hearing (20Hz to 20kHz); sound produced outside of that range is fine. The measuring device we'll use is a human hearing the firing of the gun. This should be a reliable weapon which can reliably kill a human at 200 meters, regardless of whatever is shot or projected. It should be able to survive more than one shot, at a minimum firing rate of three times per minute. It should be silent within Earth's atmosphere, regardless of the weather. The technology of the time is similar to the present time, but there are advances in magnetic technology (they have far more powerful magnets as they have super compressed magnetic material and have aligned it in the same direction. All magnets used are functionally 5 times stronger, a strong dose of handwavium included). [Answer] **It basically already exists.** Behold, the Russian S4M pistol: [](https://i.stack.imgur.com/z6eSg.jpg) This firearm, like the others in its family, uses a unique *piston-driven* cartridge. If you look in the cutaway cartridges, you will see this piston behind the bullet. When propelled by the gunpowder charge at the rear, the piston rams the bullet forward, propelling it down the barrel. When it reaches the end of its stroke, the piston seals on the front of the cartridge, preventing any noise or gases from escaping. The only noise in the action comes from the internal striker system, and the mechanical friction between the bullet and barrel. As long as the bullet is subsonic (and in this design, it is) there will be no sonic boom as it passes. While there might be some noise from the striker, at most it is a 'click' rather than the loud bark of even a suppressed and subsonic conventional round. Use an electronic primer to eliminate the noise from the striker mechanism, and integrate suppressor baffles into the barrel to eliminate any noise produced as the bullet scrapes by, and there you have it- a completely silent firearm. [Answer] No one ever mentioned a coilgun. The only noise produced would be minimal due to barrel fricion and such, because it uses magnetic fields. The biggest noise would be the capacitor discharge and the action cycling the bullet, the bonus is it has no muzzle flash. It works by wrapping a wire coil around the barrel so that when power is run through the coil it would generate a magnetic field to pull a ferromagnetic slug toward the target. Hobbyists have made some in their back yards capable of killing small game run off of 12V batteries and made of PVC pipes and magnet wire. And as a bonus you could add a destructive interference emitter. [Answer] **Laser gun** Any bullet you launch at subsonic speeds must be huge (say, an age-of-sail cannon ball) or it won't be much lethal at 200m - as in "it won't fly that long, at least in a straight trajectory". If it's supersonic, then you'll have a very audible sonic boom, no matter how hard you try. Noise cancellators are not that effective as movies would make you think (and they subtract quite a bit of power from the bullet along with some of the noise) sound wave cancellation can only be done in lab conditions. As you have been told, laser weapons do exist, and yet again against what the movies show, the effective weapon-grade frequencies are invisible to the human eye. [Answer] **Airgun with dimpled bullets.** In The Adventure of the Empty House, Colonel Adair attempts to assassinate Holmes using a special air gun. After he is captured [Holmes looks over the gun](https://sherlock-holm.es/stories/pdf/a4/1-sided/empt.pdf). > > Holmes had picked up the powerful air-gun from the floor and was > examining its mechanism. “An admirable and unique weapon,” said he, > “noiseless and of tremendous power. I knew Von Herder, the blind > German mechanic, who constructed it to the order of the late Professor > Moriarty. For years I have been aware of its existence, though I have > never before had the opportunity of handling it. I commend it very > specially to your attention, Lestrade, and also the bullets which fit > it.” > > > Propelling the bullet via compressed air there is no explosion. There is, however, a "strange loud whiz" as the bullet traverses the air. This strange loud whiz is from the air passing the bullet. This could be reduced by using a more aerodynamic bullet. Colonel Moran's gun fired unusual bullets that were thought to be soft nosed revolver bullets. Laminar flow is less noisy than turbulent flow. By smoothing airflow around the bullet you will reduce noise produced by the air. You could do this with [dimples, like a golf ball](http://bulletin.accurateshooter.com/2009/04/us-army-team-tests-radical-new-dimpled-bullet/). > > In their pursuit of a lower-drag bullet, the Army tried a variety of > designs... The dimpled “golf-ball” design was considered a “long shot” > according to the design team, but it has performed beyond all > expectations. The nominal drag coefficient (Cd) has improved by about > +.040, while cartridge muzzle velocity has increased by nearly 80+ fps because the bullet’s dimpled skin reduces in-barrel friction. What’s > more — the terminal performance of the dimpled bullet has been > “spectacular”. The Aberdeen team set out to produce a slightly more > slippery bullet for U.S. Army snipers. What they ended up with is a > bullet with dramatically enhanced long-range ballistics and superior > killing power on “soft targets”. > > > [](https://i.stack.imgur.com/kobH7.jpg) [Answer] There are already a wide variety of supressed weapons out there. Russian "Captive Piston" rounds are likely the best way to use conventional weapons (simply load 9mm captive piston bullets in a Glock, for example), so long as you make allowances for the reduced range and penetration compared to normal rounds. This isn't limited to pistols, the US Navy developed a captive piston [12 gauge shotgun](http://www.tacticaloperations.com/swatsep2000/) shell during the Viet Nam war. The US Army also experimented with [captive piston](https://medium.com/war-is-boring/u-s-commandos-hunted-the-viet-cong-with-silent-revolvers-8f6cc5cfc731) and other silenced weapons for "tunnel rats". [](https://i.stack.imgur.com/rDS4M.jpg) *12 gauge "telecartridge"* Perhaps the best place to look for inspiration would be some of the [assassination weapons](https://infogalactic.com/info/Welrod) designed in the Second World War. In addition to subsonic rounds, many used locked mechanisms so there would be no noise as the action cycled, or extreme versions of suppressors to capture and muffle the sounds of expanding gasses. [](https://i.stack.imgur.com/WiQG9.jpg) *Welrod Mk 1 pistol* The [De Lisle carbine](https://infogalactic.com/info/De_Lisle_carbine) is perhaps the most extreme example from that period, essentially turning the entire barrel into part of the suppressor: > > The Thompson gun barrel was ported (i.e. drilled with holes) to provide a controlled release of high pressure gas into the suppressor that surrounds it before the bullet leaves the barrel. The suppressor, 2 inches (5.1 cm) in diameter, went all the way from the back of the barrel to well beyond the muzzle, making up half the overall length of the weapon. The suppressor provided a very large volume to contain the gases produced by firing; this was one of the keys to its effectiveness. > > > This was far superior to the more complex suppressor of the Welrod pistol. As an aside, the carbine allows it to have an effective range of 200m, and while being shot with a.45 ACP isn't as powerful as a .308, it most certainly does the job (silent sentry takeouts, for example). [](https://i.stack.imgur.com/NuyxB.jpg) *De Lisle carabine* So the short answer is to use captive piston type ammunition if you want to use conventional firearms, or weapons with subsonic ammunition and extreme suppressors if you are willing to use specialized weapons. [Answer] A "cold-load" round is subsonic meaning the bullet doesn't make much sound in transit, nor does the escaping gas behind it. [Electronic firing](https://en.wikipedia.org/wiki/Electronic_firing), and a smooth bore could do away with all mechanical sound but the recoil is still going to make a "sound" travelling through the body of the person firing the gun. The only *completely* silent weapon I can think of is one that produces *exactly* the same set of vibrations with every shot, from projectile and weapon, and then uses [destructive interference](http://www.phys.uconn.edu/~gibson/Notes/Section5_2/Sec5_2.htm) to cancel out that vibration perfectly at source. [Answer] You won't totally eliminate all noise - but you can get really really close, so that any noise made is less or equal to ambient noise in a forest, etc. Start with a bolt action or other manually operated rifle action. Then, get something in the right caliber. You want 308/762x51 performance, it ain't gonna happen. No way to get something moving to 2700fps without breaking sound barrier. What will work ballistics wise AND noise control wise would be something like the 300 Blackout - or even properly loaded 308/762x51, although the 300BO will be much easier to develop a "vewy vewy quiet for huntin' wabbits" load. You are going to want to get a 200-230 grain bullet (15.4gr per gram if you are wondering) moving at 1050fps velocity at the muzzle, with as little gas volume generated as possible. Then you need a proper suppressor, designed around the bullet diameter AND anticipated gas volume being generated that needs to be controlled. You can build something like this TODAY for about $2500 plus tax stamp(s) and FFL fees if you live in the US and in a state that allows SBRs (short barrel rifle) and suppressors. I've shot and (not?) heard shot several AR15 builds in 300bo where all the shooter hears is the sound of the action working, the click of the hammer/firing pin impacts, and a "pffft" like opening a can of soda. A dB meter phone app measured it at 76dB about 10 feet away from the shooter - with a manually operated rifle, it would be quieter until you cycled the action. Carries similar energy at 200 yards as a 45acp does at the muzzle - 220-240grn bullet moving at 800fps. Accurate enough to hit clay pigeons (4.5" disc) at 200 yards. A 308 bolt gun, with subsonic 220 grn bullets, still let out a rather large "sigh" - still hearing safe, but the guy using it said that it would spook animals that were within 25 yards or so (contract hunter for feral pig control in some local wildlife preserves...). Edit - just came back from local shooting range, there happened to be a guy there with a suppressed 300BO bolt action. His suppressor is home made and needs improvement (but that requires a new tax stamp) but from 10 feet away with no hearing protection in I could hear the whack of the firing pin and the pfft of gas. Tried using a dB meter on my phone but the noise from adjacent ranges (separated by 15' earth berms) was masking the local noise.... [Answer] A well-suppressed firearm using subsonic ammunition is about as quiet as you can get with a kinetic projectile. Virtually all of the sound of the powder combustion and bullet acceleration is contained in the barrel/chamber lock-up and all of the gas ejecting is contained by baffles in the suppressor (the larger/longer the suppressor, the more is suppresses). The bullet, being subsonic, won't make a "crack". Of course a slower bullet is less accurate as it still must drop according to gravity (and some things like spin stabilized drag may not be as effective) and will hit with FAR less energy than a supersonic projectile, so either you have to be really close to the target or use a big heavy projectile that will rely on mass to maintain sufficient impact energy (or have a projectile that relies on some other mechanism to incapacitate/kill, like poison, explosives, etc). So now the only sound is the actual gun mechanism operating, i.e. hammer hitting a firing pin, or ejecting one round and loading another. This can be eliminated via a striker firing mechanism or even an electric one with few to no moving parts. The action of the firearm can be single shot (bolt action or break open) or at least be locked into single shot when needed (the [Navy SEAL "hush puppy" 9mm S&W Mark22 pistol](https://www.americanrifleman.org/articles/2015/10/19/a-look-back-smith-wesson-hush-puppy/) does this to prevent ejecting the cartridge which produces sound and a visual indicator) or/in addition to using something like caseless ammo or even a "metal storm" type preloaded barrel filled with bullets that are ignited in sequence (front to back) to reduce almost all moving parts. Metal storm weapons have variable accuracy (each round has increasing barrel length to build up velocity and thus have a higher point of impact) and require a barrel change to reload, but with a proper suppressor they could be virtually silent. A revolver can also be suppressed, but they require a tighter lockup between the rotating cylinder and the barrel to prevent sound from that area, or need a bulky shroud around it for maximum noise suppression. More info [here](http://www.thefirearmblog.com/blog/2016/06/15/why-cant-revolvers-be-suppressed-or-can-they/) [Answer] Magnetic dart gun. Use magnetic rings to pull the dart to speed. No other barrel exists except the magnets so that air pressure can't build up anywhere. The dart is probably more like a long thin bullet. Since the pressures on the "Bullet" are less jarring and better distributed than a gunpowder accelerated round, the bullet could more easily be made to deform/shatter on impact so that it wouldn't just slide through the body cleanly. The bullet could be any length--from a sewing needle up to the length of a knitting needle--with tiny dart-like fins at the back to keep it pointed in the right direction (they could also impart spin). As long as it shattered on impact and had some weight it would be terribly deadly. If a slower speed (Subsonic) were desired, it could have active guidance allowing it to be fired on an arc. A long thin slow sharp bullet could penetrate the body and shatter or even explode inside using the body's mass as a muffler... [Answer] In [another question](https://worldbuilding.stackexchange.com/q/107898/21222), we were asked about the feasibility of a weapon that would fire ammunition propelled at near-light-speeds. Even a 9mm bullet fired at such relativistics would never be heard by its victims, nor the shooter, nor anyone within a few kilometers from the shot. Everybody would be vaporized before any sound could be produced. The blast will be audible to those who are not caught in the fireball/mushroom cloud, though. --- Another option would be to couple any regular gun to [an LRAD weapon](https://worldbuilding.stackexchange.com/a/108398/21222). Set the LRAD to audible frequencies, and trigger it before the regular gun's shots. Anyone in the cone of action of the LRAD won't be able to hear the shots. They probably won't see it too, because they might be in fetal position with their eyes closed, and if they can stand, they would be puking. --- Barring those options, you could, you know, use small pistols with supressors? As long as you are far away from any targets the loudest sound will be the bullet impacts. --- If you really need to go for no sound at all: tazers, lasers, LRAD's can be silent. I have fired with some bows as well and they are much less noisy than guns. [Answer] How about a silencer that uses active noise cancellation? It wouldn't have to be on the barrel - actually, it wouldn't have to be on the gun at all, but probably nearby. You may have to program it for a specific weapon, but in theory, it could cover the blast of several nearby weapons at once. [Answer] It should be possible to create a'gun' that accelerates the projectile with a magnetic field. This would also levitate the projectile. No noise from mechanical contact or explosive. The longer the barrel the better. A slow acceleration would seem better for not producing an audible shock wave. [Answer] [](https://i.stack.imgur.com/UlmWb.jpg) In case of surviving in hostile world and having only some basic stuff, a slingshot might be an option (as well as bow/arrows, but they were already mentioned above). [Answer] Perhaps a gamma ray beam instead of a standard laser gun? It is outside of human sight and would very very likely give someone sever radiation damage and/or terminal cancer depending on how long you bombard them. Plus, completely silent. This is silent as the source of the radiation would be some radioactive material rather than any sort of electronically generated force or energy. Just make sure you have sufficient shielding. (<https://physics.aps.org/articles/v9/50>) Edit: Note that the ability to form the gamma radiation into a laser instead of a beam is very much desired in physics, but as of the date of this post is scientifically un-achieved. en.wikipedia.org/wiki/Gamma-ray\_laser [Answer] I can attest from personal experience that a .22 rimfire rifle loaded with subsonic .22 short ammunition and fired through a flywire silencer can be completely silent to all intents and purposes except for the "clink" of the firing pin against the cartridge, and the sound of the impact of the bullet against the target. Silent for all intents and purposes means that the sound produced is below that of ambient noise and/or below the threshold of hearing. If we were to substitute an electrical firing mechanism for the rimfire primer, the cartridge's contents might be ignited effectively silently. This would allow a subsonic bullet to be fired effectively silently. We may discount the sound of projectile impact Now, it may be argued that a .22 is of limited lethality, however there are options that can improve that. By using a .22 hollow-point bullet, the hollow point may be filled with a toxic substance... Perhaps curare. A curare-tipped .22 bullet, even if fired subsonically, could inflict enough damage to penetrate the skin at 200m, and with a sufficiency of curare, even an otherwise minor injury could easily be fatal as a result of the poison. The tip of a hollow point round could easily hold enough curare in pure form to kill most humans. ]

[Question] [ If a hostile group wanted to render Earth or an Earth-like planet completely unfit for human life, what could they do to go about achieving that end? By uninhabitable, I mean a planet on which humans are unable to survive in the open for the foreseeable future. Centuries in the future, whatever's happening could calm down and maybe allow for habitation again, but after the event, nobody could survive. The group who is rendering the planet uninhabitable wants to salt the earth, so to say. The two ways I've thought of that this could be done would be to create a Venus-like runaway greenhouse effect, or else to strip away the atmosphere, but I'm not sure how people could actually do either of those things. Other methods that I considered were some sort of biological agent that would be lethal to people or a nuclear war. These both seem like they'd be able to kill most people on earth, but radiation dies down fairly quickly and biological agents can have cures. I'd like to limit things to solutions that are feasible using modern science, and would also like to avoid the outright destruction of the planet. (So no crashing the moon into the surface.) What convincing ways could I have such an attack on Earth render it unfit for human habitation? [Answer] I would aim for [grey goo](http://en.wikipedia.org/wiki/Grey_goo). Make a group of nano-scaled robots that alternate between massive self-replication, and consuming specifically human life for resources. They are small enough that they would carry on the wind, and if they had significant downtime during their self-replicating phase, no one would know there was a problem until it had reached pandemic levels. If they leave the body once consumed, it would take ages to figure out what we were facing, and they could be made to eat through whatever containment suits/air scrubbers humans have devised to keep out pathogens. [Answer] * Start by getting all those useful fossil fuels out of the earth to deny them to future generations. Turn one half into non-biodegradable polymers and contaminate oceans with them to damage the food chain at its root. Turn the other half into carbon dioxide and release it into the atmosphere by burning it. The resulting green house effect will lead to a climate catastrophe dealing further damage to the biosphere. * Get all low-radioactive uranium isotopes out of the earth and turn it into much more radioactive fission products using nuclear reactors. The resulting waste will bother future generations for millennia. Not just because these elements are very hazardous, but also because some of them can be used to manufacture nuclear weapons. * Any liquid biological or chemical waste should be dumped into fresh-water springs to deny clean drinking water. * Speaking of drinking water: Ground water can be contaminated by pumping large amounts of hazardous chemicals into the ground in order to hydraulically fracture underground rock formations. This breaks up deposits of natural gas which can add further contamination to ground water. As an additional plus, it can also cause an earthquake or two and brings plenty of contaminated waste water to the surface (see previous point). * Drive various species of natural fauna and flora to extinction while overcultivating a few selected others. Those species should be bred for total dependence on humans to make it impossible for them to survive in the wild. The resulting biological imbalance will result in a critically unstable ecosystem which will soon collapse on its own. You might wonder: *How could I convince billions of people to cooperate with such a crazy plan?* Here are a few tips: * Establish a world-wide economical system which incentivizes short-term gain over long-term sustainability. Design it in a way that those who embody this doctrine become more powerful while those who don't get as few political influence as possible. * To prevent the humanity from realizing your plan, distract them from what is happening through a very broad supply of shallow entertainment. Mix it with subliminal messages which manipulate them to crave useless status symbols which can only be obtained by working harder for the destruction of the planets ecosphere. * When there are still people who care about politics after all, distract them by putting topics on the public agenda which are highly emotional but don't actually matter much for the survival of the human species, like gay marriage, abortion or sexism in video games. Throw them a bone once in a while by making a public statement in one or the other direction in these regards and watch them fight while you continue your plan. * To prevent humanity from allying against you, follow the good old tradition of "divide and rule". Separate humanity into easily distinguishable sub-cultures like race or religion. Then make sure they hate each other and enter pointless wars. Sounds hard? You will be surprised how easy it can be to destabilize a whole region just by supporting the right people. When the wars start, the involved people will not only stop bothering you when they think there is a greater threat, these wars will also motivate even more ruthless exploitation of natural resources and stop them from caring much about any collateral damage they cause to the ecology. In short: continue doing what we already do. [Answer] **If you absolutely, positively need to sterilize the surface, you must blast it from orbit. [It's the only way to be sure.](https://www.youtube.com/watch?v=aCbfMkh940Q)** The problem you'll quickly run into is that the Earth is big. You can crash 10km sized asteroids into it, and there'll still be some survivors to whine about the injustice of it all. Now, we wouldn't want that, would we? There are two surefire ways. ## 1. Antimatter Bombardment No, the only way to be sure is to be thorough. You'll need a fair bit of antimatter, um, let's see... 1 Mt is $4.1\times10^{15} J$ so the Tsar Bomba (in the tested config) at $42MT = 1.72 \times10^{17} J$ 2 kg of $E=mc^2 = 1.79 \times 10^{17} J$ So each 2 kg antimatter bomb (as it anihillates with 1kg ordinary matter) would have a blast similar to the [Tsar Bomba](http://en.wikipedia.org/wiki/Tsar_Bomba), the most powerful nuclear device ever detonated in the puny humans' history. That gives you a nice $1,200 km^2$ blast incineration area. Now, if we were sloppy, we would just pepper the land area of $148,300,000 km^2$, so about 1,236 MIEVs (Multiple Independently Targetable Entry Vehicles) with 100 2kg warheads each would do. But that would miss all the boats, planes and submarines crowding their primitive buoyancy based transportation lanes. With [about 100,000 ships](http://unctad.org/en/docs/rmt2011_en.pdf) out there, that's a lot of survivors. $361,000,000 km^2$ to cover, you'd need another 3,009 MIEVs. You might still miss a submarine or two, but without space launch capabilities, zero industrial capacity, and an all-male crew, you're set anyway. Pro: Clean blasts, little of that nasty radioactive slag. Also, once in atmosphere, any attempt to shoot down will only damage the containment system and detonate the antimatter. Con: You need a lotta bombs. --- ## 2. A dozen or more relativistic ships. Thanks to our friends at [Wolfram Alpha](http://www.wolframalpha.com/input/?i=relativistic%20kinetic%20energy&a=*C.relativistic%20kinetic%20energy-_*Formula.dflt-&a=*FS-_**KineticEnergyRelativistic.K-.*KineticEnergyRelativistic.m-.*KineticEnergyRelativistic.v--&f3=3000t&f=KineticEnergyRelativistic.m_3000t&f4=0.25%20c&f=KineticEnergyRelativistic.v_0.25%20c), I don't even have to do the calculation myself. Take your standard light-crafts, a 3,000 ton craft, push them to a reasonable 0.25 c and crash them on opposite hemispheres (preferably from multiple directions, but you could also do several hours apart). Each will clock in at around $8.8\times10^{21}J$, or about 10,000 times those anti-matter firecrackers from earlier, or about the same as a 10 km asteroid impact. To be really sure, send a few dozen of these. Pro: Almost impossible to intercept once acceleration is complete. Con: Your reptilian colonists awaiting in orbit might themselves cook a bit from the impact gamma blasts. [Answer] Simply unleash the entire world's nuclear arsenal on the planet. If you aim for population centers, the majority of the population would be vaporized or killed by acute radiation poisoning. This has the added (dis)advantage of destroying or irradiating most of the useful technology (factories etc.) making it difficult for humans to rebuild. The fallout would probably cause global radioactive rain, bad for any remaining survivors. Finally, the resulting [nuclear winter](http://en.wikipedia.org/wiki/Nuclear_winter) would devistate the ecoystem. Without the abundance of plant and animal life we are used to, humans would find it difficult to survive in the decades or centuries it takes the earth to recover. [Answer] biological's are very hard to be %100 fatal and still spread. If you have a very good designer you might a huge number but there will always be survivors. Chemical poisons, have another issue. Volume and production. It would take a huge amount of resources just to completely wipe out a large city where the people are concentrated. Nuclear also has it's issues, unless you are able to get all nuclear powers to launch their arsenal around the globe and bring about the holocaust and nuclear winter. That might be pretty close. I suspect the simplest one would be to deflect a decent sized asteroid to slam directly into the earth. I would guess if you had the ability to aim for the middle of the Pacific Ocean. If it hits the ocean there will be huge Tsunami's that make the anything we've seen look like a wave pool, maybe a half mile high wave front? More? There will be a huge amount of heat dissipated by vaporized water and the impact would likely cause a lot of volcanic activity, adding a lot more stuff into the air. I would say a second best would be a biological agent that generates a poison, such as botulism, only it is virulent like the flu or common cold with few symtoms. The agent doesn't kill, but the poison it generates does. This way it can spread quickly and widely long before the poisons start to build up and take effect in the host. [Answer] Assuming that this is set far enough in the future that space travel is possible to some degree (I'm guessing it is, otherwise I don't know why anyone would choose to destroy a world) the easiest solution is dropping *any* mass on the earth. It doesn't have to be a comet, moon, or anything nearly that large. Run your average space ship into the earth, or have simple projectiles that are designed to accelerate towards the planet using whatever propulsion system everyone uses. Any mass going at a decent speed will be able to create a nuclear winter as easy as our nuclear weapons would. Ideally you would have someone bombard the planet from a few different angles, to throw up dust all over the planet rather then having one area completely saturated with dust and the other side of the planet still being potentially inhabitable. Any space fairing race will find simple mass projectiles to be easy and cost efficient way of rendering the place uninhabitable. In addition if this isn't planet earth your talking about you could set up another option. Perhaps you have a world that is being terraformed but isn't hospitable to human life yet. If people are living on it using domes and complicated terraforming technologies then those technologies could easily be disabled through virus, sabotage etc etc. The planet it self could easily be so deadly that it doesn't take much to ruin humanities precious grip on it. [Answer] Two words: Methanogenic Microbes Check out this wiki page on "The Great Dying" aka the Permian-Triassic extinction event: [Great Dying](http://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event) Killed 90% of all marine organisms and 70% of all terrestrials; only known extinction where even **insects** were affected. **Insects!** From the wiki regarding methanogenic bacteria: > > According to a theory published in 2014 (see also above), a genus of **anaerobic methanogenic archaea** known as Methanosarcina **may have been largely responsible for the event**.[126] Evidence suggests that these microbes acquired a new metabolic pathway via gene transfer at about that time, enabling them to efficiently metabolize acetate into methane. This would have led to their exponential reproduction, allowing them to rapidly consume vast deposits of organic carbon that had accumulated in marine sediment. The result would have been a sharp buildup of methane and carbon dioxide in the Earth's oceans and atmosphere. **Massive volcanism** facilitated this process by releasing large amounts of nickel, a scarce metal which is a cofactor for one of the enzymes involved in producing methane > > > Note the massive volcanism, which is thought to have been caused by a bolide impact (the trigger for this cascade of catastrophe). If that doesn't kill us, the forces of nature might as well give up. [Answer] One practical solution that hasn't been mentioned yet is simply to move the Earth a bit. The Earth orbits the sun in the [Goldilocks Zone](http://en.wikipedia.org/wiki/Circumstellar_habitable_zone), where is neither too hot nor too cold for human survival. Bumping it a bit further from the Sun would ensure it becomes totally uninhabitable for humans, with the bonus that it could be undone by simply moving it back again. Actually moving the Earth is probably easiest to achieve with the [gravity assistance method](http://qntm.org/moving). Using currently available technology, you can simply send robotic spacecraft to attach a means of propulsion to nearby asteroids and accelerate them into a close fly past of the earth. This will affect the trajectory of the asteroid significantly, and the trajectory of the Earth slightly. Repeat this with many asteroids (reusing them if desired) and you can divert the Earths orbit however you wish. [Answer] I doubt that it's possible to destroy all life on Earth using present technology. Realistically, I think science fiction stories -- both those published as fiction and those which claim to be fact -- tend to overestimate the power of human technology. Consider: People very regularly try to kill off large numbers of other people. We call it "war" and "genocide". And yet, there has never been a war in human history that has even significantly slowed the growth of human population. World War 2 resulted in something like 25 million deaths. Certainly a terrible tragedy, but in 1940 world population was about 2.3 billion while in 1945 it was about 2.4 billion. The catastrophe of WW2 didn't reduce population, it just slowed the growth a bit. Biological weapons can certainly be horrifying. One can certainly imagine a biological weapon that would wipe out all human life. But in practice, there always seem to be some number of people who are naturally immune. Presumably if the U.S. or a European country was attacked with a biological weapon that caused massive deaths they would devote every available resource to finding a cure. Would they find one in time? Who can say? Similarly, nuclear weapons certainly make it possible to kill many more people than in the past. But even there, you might kill a significant percentage of the population, but 100%? You could certainly cause massive casualties if you dropped one bomb on New York City, but no one has enough bombs to hit every isolated ranch in Montana. Some number of people would hide out in bomb shelters until the fallout and died down. Etc. In any proposed disaster -- natural or man-made -- one can construct plausible scenarios for how you would kill millions, maybe even hundreds of millions. But even if it's literally possible to kill billions, it would be very very difficult to kill every last person. Surely when the disaster struck, there would be some people in very isolated places, like a remote ranch or mining colony, a research station in the Antarctic, etc. And some number of people would be prepared and would have suitable shelters. Of course if you set the story in the future, it is at least plausible to suppose that even more advanced technologies of destruction are possible. Maybe people or aliens or whomever will invent an incurable virus, a bomb that can blow up the planet (well, you ruled that out), etc. For a fiction story, you don't have to present a rigorous academic argument how this technology will work. You just have to come up with something marginally plausible, throw some fast techo-speak past the reader, and boom, you're there. Personally, I'd suggest that if you want maximum plausibility, you make it a multi-pronged attack. If I was going to try to wipe out all human life, I would launch a nuclear strike AND a biological agent AND an army of robots that will relentlessly hunt down the survivors. But I'm still working on perfecting the design of the robots so it will probably be at least another year or two before I'm ready to take action. [Answer] Detonate several Tsar bombs at a high altitude at the same time and you will completely destroy the ozone layer in that part of the world. <http://en.wikipedia.org/wiki/Tsar_Bomba> [Answer] Actually one way for a hostile group to render the Earth uninhabitable with no repercutions for the group, itself, whatsoever is to simply fund oil companies, city expansion, poaching, hunting of wildlife, damming of rivers (covering them with a dam, not cursing them from God :D ), lumberjacking, etc. while at the same time funding anti-greenpeace actions, anti-hybrid/elecrocar research, basically any kind of research or action that strives to conserve the Earth nature. [Answer] I would like to offer an easier solution that is extremely feasible. Take use of [Harmful Algal Blooms](http://en.wikipedia.org/wiki/Harmful_algal_bloom#Harmful_algal_blooms). By adding iron to certain parts of the earth's oceans and lakes will cause an explosion of algae. While some theorize that iron fertilization can help our planet, some areas contain species of algae that are essentially toxic. Another harmful effect would be population booms of deep sea creatures an other bacteria which would feed on organic bloom detritus. These organisms use oxygen, and a growth in population could lead to an anorexic environment. We've seen these types of blooms occur before, and they were simply caused by the run-off from industry flowing into rivers, lakes, and oceans. If it were to be done in a concentrated effort, the effects could be catastrophic. Sustained feeding of iron to the earth's ocean can be done for decades (It doesn't take that much for the effects to show). [Answer] I think a lot of people missed an important part of the question: The issue needs to persist for centuries. Nothing nuclear meets this criteria. Despite the anti-nuke hysteria it's not going to be dangerous that long even if you turn every bit of mined fissionables into dirty weapons. Biologicals might work but you need something that will persist harmlessly in some host and yet kill humans. That's probably beyond current tech to develop. Blasting the ozone layer won't persist long enough. I do see one approach that would work but it would be awfully slow. Bring down enough comets. Turn the Earth into a waterworld. [Answer] Slowing Earth spin will weaken magnetic field. Which will make dry land uninhabitable because of radiation (not oceans tho), and will increase atmospheric loss caused by solar wind (like Mars). Suggested by answer to question [Could we still live if Earth's spin speed slowed down by 90%](https://worldbuilding.stackexchange.com/questions/8408/could-we-still-live-if-earths-spin-speed-slowed-down-by-90) by @Physicist137 [Answer] You basically want to Venusform Earth, i.e. raise the median temperature of Earth above 100°C. That's quite easy: Just continue burning more and more fossil fuels as we do today. Eventually you will a get positive [feedback loop](https://en.wikipedia.org/wiki/Climate_change_feedback) and a [runaway climate change](https://en.wikipedia.org/wiki/Runaway_climate_change). [Answer] A method not discussed here could be [Snowball Earth](https://en.wikipedia.org/wiki/Snowball_Earth) - the exact opposite of the greenhouse effect. *Lower* the amount of greenhouse gasses in the atmosphere and/or block the sun's radiation from reaching the planet (maybe an overzealous attempt at geoengineering) so that the planet starts to cool. Glaciers, snow and ice would start moving from the poles towards the equator, rising the planet's albedo and thus having even more solar energy reflected back into space without heating the planet. Thus you get a positive feedback loop that cools the planet even further until the whole surface is covered with ice. Higher lifeforms would die off in the planet-wide arctic conditions because they lack temperature tolerance or by simply starving. In the end, the planet would be devoid of higher lifeforms, single-cell organisms or microbes may survive on the surface, marine life may degrade, too - the thick ice coating would block out the sunlight, bringing marine algae photosynthesis to a halt, too. Black smokers or volcanic vents on the seafloor may provide energy for complex lifeforms, though. Humans might survive in biodomes or in closed environments, but the planet as a whole would be unsuitable to sustain higher-order life. ]

[Question] [ We've all heard the stories. The unbelievably chaste Sir Prancealot having the strength of ten men. The undefeatable members of the Kung Few, equal to any five hundred lesser mortals. The frankly amazing feats of the 299.5, who held off an army of 20,000 until they were betrayed by some bloke with a herd of goats. The legendary Hercufleas, who single handedly defeated the god of all cats in mortal combat... Clearly people like these are exceptional, capable of feats that make normal human beings look paltry and sad, and any one of them would make a king or kingdom that could lay claim to their loyalty a global superpower able to crush their neighbours and potentially bend even the gods to their whim. Even a single relatively puny 'legendary warrior' could completely turn the course of a major battle, assassinate a rival king or destroy a town single handed. Given a world of roughly 300-200 BC in which mythological gods (limited power but still big enough to seriously mess with someone's day), beasts, demigods and monsters abound, how can we go about creating a situation that such a power doesn't lead to one state overpowering the others with the might of their 'legendary hero'? Please note: The same question can be expanded out to any timescale and/or world and is fundamentally 'How can I, as a world builder, establish a balance between many powerful states and many weaker states', but for the purposes of this question please focus on how generally applicable world-building concepts can be used to resolve the 'legendary hero' problem (to avoid this question being far too broad in scope). [Answer] *Dune* provides a pretty good model here, and so does the Cold War - balance your heroes against one another. In *Dune* you had several powerful groups, each with their own type of power, balancing one another out. The Emperor had the most effective military in the galaxy in the form of the Sardukar, extremely well-trained and disciplined soldiers who could defeat any other soldiers in the galaxy. The noble houses had their own individual military forces as well as atomic weapons, and while no one house could possibly hope to defeat the Sardukar, if they all banded together against the Emperor they could have taken him down. And the Spacing Guild had little or no military at all, but they controlled all FTL travel. This is what you need in your world. The Kingdom of Greatbigistan is home to the Legendary Hero Bill, who could defeat any other man in single combat, but the neighbouring lands of Notasbigistan, Midsizeia, Reallysmallland, and Smallbutstrategicallylocatedsburn each have their own heroes - not Legendary Heroes, perhaps, but at least Folkloredary Heroes. Individually, none of them could defeat Bill, but if Tom, Eddie, and Sarah all teamed up they could at least break even against Bill. The King of Greatbigistan thus needs to maintain good relations with his neighbours, and his neighbours need to stay allied to ensure their buddies will come to their aid of Bill attacks. You can also add an element of Mutually Assured Destruction. Bill of Greatbigistan is powerful, but Sam of Reallyrichtopia is equally powerful. If Bill and Sam ever really went at it with one another, they'd kill each other - and probably everyone around them as well. Of course, if Bill teamed up with Tom, Eddie, and Sarah... This is the exact same situation we had in the real world during the Cold War. Individually, the US could have defeated any Warsaw Pact nation (except perhaps the USSR); individually, the Soviet Union could have defeated any NATO country (except perhaps the US); and the US and USSR could have wiped each other off the map, at the cost of their own existence. [Answer] Well, why does the US with their massive military not conquer the entire world or at least the Western Nations they have a cultural affinity with? I mean there are several reasons, mainly their population would object, their opponents would rally together and politics. Alexander the Great conquered much of the known world at the time. Sure he stopped because he died but there were plenty of issues. Mostly in communication. How do you govern a realm when your decrees take months if not years to reach your subjects? You don't need to stop them from conquering, they'd never manage to hold such a realm. With time after several failed attempts people will learn. Except for that one asshole of course but you just let a goat herder betray them ;) A single hero can only be in so many places at once. Same reason one super space ship is a bad strategy. It will be a death by a Thousand cuts. Invading barbarians, corrupt politicians, civil dissent, language barriers etc. If this isn't enough, what about a lack of ambition? It's unlikely China will police the world in the same capacity as the US has done. Not because they will lack the power in the future, but because they have no desire to do so. They wish respect, total power of their own backyard. As long as we accept them with the respect they desire they don't care about the human right violations that would happen in Spain or Ireland. They simply lack the ambition to go police us. So that too could be a reason. Do the heroes even want to conquer the world? [Answer] ["Amateurs talk about tactics, but professionals study logistics."](http://www.military-quotes.com/forum/logistics-quotes-t511.html) If each country has a king with a certain number of Great Warriors, and each country expands as far as their heroes can push, there's still plenty of practical limitations. For example: 1. travel times are high in pre-car civilisations. A nation of human/bear hybrids might conquer less land than an army of weaklings riding war-emus, just because they can't lumber to the battlefield in time. Until the world-builder needs the bear-men to expand their territory, at which point they just invent unicycles or something 2. even the mightiest warriors are tethered by their supply line. The great hell-beast Qorn might squish any that tread in its path, but it's fed by the souls of virgins and won't so much as squish a fly if you can't get a steady stream of virgins to sign the disclaimer 3. countries with few heroes will rapidly expand then contract. One moment they're pushing the bear-men around like matches. Then Sir Prancealot pulls a hammy, the Kung Few come down with the kung flu, and the 299.5 get each other pregnant and become the 449.25. Suddenly this all-conquering nation is defenceless and due to be taught a lesson 4. conversely, countries with no heroes can suddenly expand if one turns up. A little boy sees his parents pecked to death by war-emus, and the next thing you know there's a barbarian with an unexplained Austrian accent rampaging through the countryside Given the number of things that can go wrong, the God Emperor's holy beancounters will often recommend the legions of doom stay home and use their talents to ensure taxes get collected. They might leave a few provinces unnecessarily unseized, but they'll have more resources available when they suddenly discover Godzilla mooching around Tokyo again. [Answer] The Legendary Hero, having proven herself during the initial war, becomes the greatest remaining threat to the leadership of the country they just saved. She has a greater claim to the crown than any who have ever, or are currently, wearing it. So the unwritten epilogue to every hero quest you've ever read, involves the hero being betrayed, beheaded, imprisoned or banished from the realm. Only by swift action can a mere mortal king defend his throne from a hero. And once the hero has been neutralized, the balance of power between the kingdom and the surviving surrounding nations returnsto normal. [Answer] Asymmetrical powers are entirely normal in international relations. Here are a few things that make this work in (our) reality. ## A Balance of Power One strong nation can be balanced out my a large number of smaller nations opposing them. This isn't always a military content, but it can be. Even a single very strong nation can be deterred when they realize that they will have to deal with many smaller opponents. This is touched on in many, if not most, of the other answers. ## Power is Multi-Dimensional Power should not be understood on a single dimension with weak nations on one side and strong ones on the other. In reality, a nation may be very strong in one area (religious authority) but very weak in another (economic power). A theoretical legendary hero may be most important because they embody the important beliefs and values of their society, making them an incredibly influential figurehead on important issues. However, they might find that they can't effectively do much because they lack legal authority, law-making power, wealth, or a variety of other things. Things which their enemies have. ## Political Institutions Institutions are the formal bit of politics. Today, we would typically think of laws, legislatures, the executive (President, Prime Minister, King), courts, etc. There are also international institutions (laws or customs, international agreements or alliances, rule-making or problem-solving bodies). A single strong hero may or may not have access to these institutions. They may or may not be friendly. In practical terms, these institutions can mitigate the hero's power. Domestically, they may not be able to lead a nation or raise an army - they don't have the legal ability to authorize the funding, or the political authority to recruit soldiers (and more). They may find that parties within their country oppose them - and that those parties are way better at politics than the hero! Internationally, there may be important agreements or customs that prevent the hero from being successful. The nation of the world may have already established agreements preventing their use in civilized warfare. There may be strict consequences, even from nations not otherwise involved in the conflict. ## Political Culture Culture is the set of values a people share. Most people share sets of values about the appropriate use of authority, force, legitimacy, etc. - these are political values. In reality, a government has a nearly infinite range of possible actions, but the vast majority will never be considered because they are not acceptable (or conceivable) to their culture. Perhaps in the fictional culture it is not appropriate for the hero to involve themselves in politics, either because politics is "dirty" or because the hero is above it all. Perhaps they have a limited range of things they can use their divine-gifts for. Then again, the heroes themselves may have a set of customs. Perhaps heroes teach other heroes what is okay and what isn't, and so they have an informal agreement that they should not interfere in these events. [Answer] They are legendary heros. They are not legendary soldiers -- the don't take orders; or even work well as part of a team. They don't serve a country, they serve a higher cause; or they serve a lower cause (off having their own personal adventures) Even the ones who are infact soldiers, are not part of any nation's army; they serve their own causes (exceptions may apply see bottom). I suggest looking at [Erikson's Malazan Book of the Fallen](https://en.wikipedia.org/wiki/Malazan_Book_of_the_Fallenz). This world has many god and demigods wandering around (Ascendants). It has off the top of my head at least 4 warriors so great that no-one could stand against them. Several races of eldar beings, who's few surviving member are certainly in the legendary warriors category. It even has 2 immortal armies of great warriors (T'Lan Imass, and the Crimson Guard.) The real trick comes down to the fact that the world is big. Heros are simply so rare, your average person will never see one, and your average kingdom would have trouble tracking them down. * Earth has 148,940,000 sqkm of land. * Lets say there are 500 such legendary heros in the world. + Counting any Armies etc as a single hero, since they will stick together. * this means if uniformly distributed each hero has 297,880 sqkm + That is pretty close to the land area of Italy (294,140 sqkm) + it is about a 545km by 545km square + That means they are [about 10 days travel by horse from each other](https://worldbuilding.stackexchange.com/questions/6411/) Obviously assuming uniform distribution over land area is not good; that isn't how people move about. But that *are* heros, many are notable for exploring lands no-one has been to before. What else are they up to? * Some only want to reclaim/defend their homeland. This is a good thing for an army of heros to be at (Your 299.5). It is probably fairly compact in area. Woe, onto anyone who tries to take it from them; but they are not expansionist -- because that it not the genre convention. * A great deal are probably engaged in hunting demons and dragons and legendary ~~rogue heros~~ villain terrorizing the common folk -- or even the nobility. * At any point in time, probably X% have sworn to retire; never to do violence again. * A surprising number are fighting in the underworld to find their lost loves etc. (if this is an option). Some remainder is willing/able to participate in a nations conflict. Probably, not because that nation has earnt their loyalty; but because it aligns with the hero's own goals. We have to divide these into two types: Solo heros, and hero army's. Solo Heros can't win wars -- only battles. Cross-reference: [In what war would one modern military vehicle make a difference?](https://worldbuilding.stackexchange.com/questions/12219/) Your heros are no more powerful than a Challanger battle tank. Notice that a lot of the answers to that question rely on the fact that they are sending it backwards in time and so have perfect intel as a bonus -- not something your chronoically-regular hero has. Notice that many of the others rely on the face that the tank can destroy nearly anything within a 2.5km radius of its position -- most heros can't do that. So there are strategies to deal with such things. - The enemy army goes around him (particularly if the hero is slow -- honorably taking prisoners rather than brutally slaughtering everyone). - The war it fought on many fronts -- the hero can't be everywhere - and good counter-espionage could trick him into being in the wrong place. - Blackmail, Bribery, pleas for reason, and other manipulations may be employed to convince the hero to sit this fight out. - obviously countering with your own hero - Who many infat be drawn into the fight soley because the first hero was deployed; perhaps as a chance to take on a long time rival - and given there are a lot more free heros roaming the country-side on their own quests; they are probably much easier to draw into a fight for the under dog this way Now lets think about what happens in a battle with the hero: * If he can be defeated by numbers; then he will be defeated by numbers + If he is worth 100 other men then that is piddling change in an battle of 10,000s. If he is worth 1,000 men, then he will probably not survice a battle with 100,000s (say 60,000 each side). If he is worth 10,000 men he should perhaps be considered unable to be defeated by numbers. See next point. + I suggest that heros that are merely great men, like the heros of the Trojan War; who barely more than human, and the ones most likely to be in a war, rather than adventuring alone. * If he can not be defeated by numbers, then he will kill so many, so so many. + One day he will look out on a battle field from a top a mountain of the slain. He will see the thousands of dead enemies -- who he knows are people too -- dead at by hand. If the battle was hard fought, he may be the only one left standing, his allyies all dead. (Afterall, you can't send him alone, or the other side will simply go around him, see above.) + This will surely break him. + Either he decides he likes it, and develops a bloodlust that will eventually devour his own -- making him a villain (to be hunted down by heros, see above) + Or he swears off violence and retires (see above: this is why so many heros are retired). The other side is the Army of heros; again assuming they are willing to take part in expansionist wars. They will conquer until they can not conquer any more. Obviously this limit comes before the entire world, or your setting would not be one with multiple nations. * There may a barrier they can't pass. This is up to you to work out, there are plenty of options. + Maybe their kind can't cross water, so are bound to a continent. + Maybe their power is geographically isolated. Their power coming from the spirits of their ancestors on their ancient lands; or only working will in sight of the great mountains high world tree. Or to stay strong they need to drink water gathered within this moon-cycle from the sacred spring. + Maybe their continent is just too isolated -- the oceans are too great to transport an army across. * Or they grow until there empire can not be organizationally maintained. + empires can only be so large before they break down due to shear size, and organisational difficulties. + Perhaps the expansions stop at that point (unlikely) + Or the empire crumbles from within; heros end up fighting each other, as their home provinces war. Or have to be divided up so sparsely as nations try to secede in all corners of the empire. In short, Legendary Heros don't normally fight in wars. They have much heroic things to be doing. Those that do: One man can not change a war. He can only be in one place at a time. A army of such men is unstopable by others, but will still not be able to grow without bound. [Answer] I think in lore the primary reason this doesn't happen has a lot to do with personality. When the 'legendary hero' is good, they may consolidate power or support someone, defend their kingdom or attack an enemy kingdom. However, they don't just take all the power they can as fast as they can. 'Bad legendary heroes' on the other hand, seem to always be looking for ways to expand their power, and end up being betrayed (as many other comments mention) or take on too much to handle and fall short of their goals (death by a thousand cuts al-la @Mormacil's answer). The oldest English written work is expressly about a legendary hero who does consolidate power, but stops when it's at the point it benefits his people the most. Beowulf is a classic, specifically about maintaining balance of power. He defeats great evil, builds a kingdom, then defends his realm and his people by being stronger than the rest. It might be that the best balancing mechanism you could have is larger == unwieldy and/or less powerful per individual while smaller == more skilled and/or powerful per individual. [Answer] For anything, there is no benefit to attacking something when you gain less than you loose. From a game theory standpoint, a country expending resources to conquer another country to encapsulate their populace doesn't benefit the people of country which attacked, unless enough resources were plundered to be worth the attack, or if there is increased respect/expectation of the country fighting in response to some action. The same rules apply to individuals and smaller groups. The other factors at play are social, like nationalism and stigmas against stealing from others, which don't necessarily make sense from a game theory standpoint, but are clearly things that appear in humans and could in any fantasy scenario in any capacity (e.g. It is forbidden for a god to threaten any other). The resources expended vs gained in conquering might also be too risky or catastrophic in nature. This is how you might describe mutual annihilation via nuclear weapons. So perhaps two gods from two fantasy civilizations might not be equal in terms of power, but they could both threaten to destroy at least half of the other country before the other one could do anything about it, which would ensure both of their safety if both civilizations have their own existence in their best interests and social interactions are negligible. [Answer] In virtually any mythos, the gods and heroes are brought down by some weakness (generally *hubris*, and this applies to other pantheons besides the Greeks). Yes, your mythological hero is capable of great feats of strength, cunning, day trading and mixing martinis "shaken, not stirred", but gradually this goes to their head, and they stop looking at the important things. Achilles arguably did more damage to the Greek army by sulking in his tent in a dispute over honour than the Trojans did in the previous 9 years. Alternatively, fate has already decided against them, so the answers the 3 witches gave don't mean what the "hero" thought they did. [](https://i.stack.imgur.com/NAMaT.jpg) *That **isn't** what the three witches meant?* So the heroic deeds of your dragon slayers, kings and knights of renown, sous chefs who can defeat Gordon Ramsey in a cook off and others are eventually done in by karmic balance. That is the real reason that these heroes don't take over the world. [Answer] I think there are actually two things here. One is "why aren't they rulers in their own right?", and the other is "why don't those they swear allegiance to use them to dominate their competition?" I'll answer each in turn. # Why aren't they rulers? Not all heroes are good rulers, and many don't even *want* to rule. Prancealot is devoted to his religion moreso than he desires to be a ruler. The Kung Few have always been treated well by the Emperor and have no desire to upset that status quo. The 299.5 are soldiers, not administrators - and besides, 299.5 people trying to co-lead a nation would run into disputes over the best way to do things - and Hercufleas mostly just wants to retire to his farm. # Why doesn't their sovereign use them to conquer? In addition to the points others have made about the balances of power (that is, other kingdoms have their own heroes and other heroes could band together, etc), there are reasons that the heroes may not be able to be swayed by even their lord to use their skills for their own gain. Prancelot's religious convictions make him want to defend the innocent, not conquer. The Emperor is wise enough to know that the Kung Few have a good point that their already impressive empire doesn't need to conquer the smaller states around it. The 299.5 recognize that their situation was unique and they don't want to push their luck. Hercufleas still just wants to be left alone to his farm. Now, a clever king could persuade even these heroes. "Prancelot, bring your religion to the heathens", "But the Kung Few, this nation over here has the temple holding the ancient scrolls of the Kung Many", "299.5, you are soldiers, what else are you going to do?, "Hercufleas, if you don't I'll burn down your farm." These things tend to end poorly for almost everyone involved, of course, because myths are usually Aesops. [Answer] But they do overpower everything. In story you just close them in geographically region so they don't clash with other superheroes (as in we ignore their existence). For example king Arthur dies when fighting with someone equal from his story, no Vikings or Arabs. Samson is unbeatable until his hairs are cut by treason not by fight with Greek heroes. But your main problem is solved by a person from myth about a demigod Hercules/Heracles. You just send the guy to do some chores one after another. And yes, he may be changing the history it took 20 years for somebody else (Troi) but it's not your concern. Of course if you are the king of Troi then it is your problem. But hey, it's not like it never happened before. Because you know, people fought over that damn city multiple times. What you must remember is that if gods meddle with mortal affairs they act like mortals. So they change sides, aid different people and so on. And if you have demigods and beast they don't live forever. So after 50 years things get back to normal. By normal I think "people fight they own wars". [Answer] That's not the nature of heroes. A hero doesn't want to rule; he wants things to be *right*. That things which should be done, are done, and things which should not be done, are not. He makes it so. He doesn't think he is special. Talk with any real-life hero and you'll always hear it: "I only did what anybody would do." The hero would like to just be ordinary and competent, and live in peace, never even thinking about whether there *is* a king somewhere, but *things* keep coming up and he has to deal with them because, well, that's what you do when *things* come up. As for the ruler who wants to use a hero to conquer the world, he runs a grave risk: the hero may ponder his orders and decide that his king *has become evil*, and thus sadly the hero must now destroy him. [Answer] It's hard to address all possibilities why Heroes or state of Heroes wouldn't rule the world. To point some of them: * Power of state is not sum of heroes. Not all heroes will dot on the state. By nature they would like to live their life along with their ambitions, be it peaceful farming or government. As long as there will be no propaganda involved, only a few of them will be controlled by or in state and the degree of said control will vary. Saying so, any war will mobilize heroes from whole area to stop the threat for peaceful life of others. * Weakness exploit. Weak have wits and will use any weapon at their disposal especially at desperate times. For any measure there exists counter-measure. Even weak goat herder may bring Hero to his fall. * Power play. States with Heroes will be more interested in breeding more powerful heroes or at last try to match-make some of them to produce more heroes. Government will attempt to create social and legal measures of control over Heroes to control them. They might be so focused those actions that they effectively cannot rule they world. Possibly the best Heroes compete on some kind of Olimpics to demonstrate who has the most powerful Heroes? In this case sports competition would have drastic effects on diplomatics and reversely, some heroes would be instructed to perform below their capacities. * Raging beasts. Heroes under control of state are more involved into "pest control" of monsters. States would not be able to really use heroes for invasions, more over to maintain peace it would be necessary to use big garrisons, as Monsters are able to easily trash feeble lives of citizens. * Power Divided, geographically Heroes are normally dispersed or their "power" or "mana" is taken from their location. If even some state is able to gather Heroes, they would become weak due to division of power between Heroes in location. Saying so, heroes couldn't be used in normal army and could be overpowered by normal people. * One for All, one Hero (unless some cloning will be applied) may be only in one place at once even if he's able to teleport or use some quick transportation. No sane state would risk war in which such a famous Hero would have to be sent for invasion as their loss would heavily hit morale. Heroes would be rather used as guardians, reserved for representative purposes or propaganda and that's why duels of Heroes would be legendary. Saying so, in such setting duel of heroes would mean decisive battle when it's necessary to unleash everything at one's disposal. * No synergy, Heroes are bunch of individuals. They simply to not cooperate just because they are told to do so, have different relationships with others and ways of dealing with "troubles". As for nation made of superpowerful beings their ability to expand/invade would be restricted by their ability to cooperate and communicate as well as numbers and reproduction rate compared to normal humans. As long as they could be killed and were a deadly threat people would develop methods to deal with them as in "Weakness exploit". To prevent that state of supernaturals would have to get involved into politics and that the real world logic would be applied with usual problems like: * Social schism, in every society there are different opinions on EVERY matter even if not spoken loud. * No interest on weaklings, due to fact that weaklings outside do not matter, inner struggle for position becomes most important. State does not take action outside borders of Supernatural State. * Economics, condensing power is cost-ineffective that's why supernaturals may discover ways to easily profit working between weaklings and disperse in search for equally easy life which probably could cause at first some side-effect economical quakes in neighboring countries but prove beneficial to both sides (mind 'Power play'). * No motivation, why Supernaturals would be interested in world domination? Most probably they already feel superior and that's why they don't really need to prove it to others unless they are not properly respected. They may have also other goals like "live untroubled" or "pursuit for knowledge". In my opinion: As for using Heroes to slain armies, for any normal human war makes shattering experience. Using heroes this way would provide the quickest way to lose them by psychical wear off or death. Due to the power of heroes it would be too much risky for most states to employ such strategy. More over tragedy of war could quickly mobilize or create many powerful heroes on the opposing side or provoke retaliation of other countries. As for rule of Heroes, powerful entities would rather not be interested in politics and bureaucracy or be effective leader of the world which would for the most part depend on maintaining control. Single Hero would be easily opposed and as for gathering other heroes they would most probably have different agendas like it normally takes place, there would be also differences of characters. Such situation would need more social skills than just supernatural (excluding mind control or some other ways of "persuasion") which would need Hero already less oriented towards combat. There would be also problems of cooperation between Supers and Normies which at some moment would have to interact. By nature there is no balance, it is just that there are more satisfying, more profiting and less risky options that are used by "more powerful" ones than destruction of opposite party. This is why they stay "more powerful" than other parties and maintain "balance". As for more simple minded answer: It's not like legendary heroes cannot rule the world. It's just that they would need appropriate means (like tech) wits (not necessary own, trusted group of specialists or crafty friends will do the trick) time and structures at their disposal to maintain it. [Answer] They can't be. If they would be balanced, it would mean that the weaker state isn't weaker. There are various possible reasons, why a more powerful state doesn't conquer the weaken, we could talk a lot about non-military power, soft power, technical development, strong religion, and so on, but all of them results that the "less powerful" state isn't really less powerful. [Answer] Well, quite often they do - look to history, when our forebears were knights in armour that could kick the ass of any number of peasants armed with pointy sticks (I guess the closest analogy we have to the supernaturally powerful) They ruled like a different class. In some countries the peasants were considered property. And these powerful guys banded together to ensure their dominance. In the UK, it took the black death to break this system - when the peasants all died, the landed nobility found there was nobody left to make their sandwiches and were forced to change the system. Similarly, the first world war changed the established practices of a ruling class for a similar reason. In a fantasy setting, the only thing stopping them are other powerful entities (via war or invasion) or themselves (because they can't be bothered with the boring task of ruling, or they have different interests like the wizard who can command armies of undead simply prefers to play with his books)(note some of these guys will simply get a steward or chancellor to do the boring ruling jobs instead and he sits around as figurehead for the glory) [Answer] Short answer: its not safe. Igor the Invincible decides to go full evil and starts burning out peasant houses with the families inside it. Unfortunately, around house one hundred he starts burning the house of Mary the Blacksmith's wife, formally Mary the Marauder, who is truly upset about trying to murder her family. I guess the Holy Handgun of Smiting is coming out of the jewelry box... Not to mention that Mr. Bigger-Than-You, protector of the realm could eat Igor for breakfast. It's his town and he likes it nonviolent. ]

[Question] [ I'm working on the timeline for my world, but I keep getting stuck at the origins. I want to have had an advanced civilization (modern levels, maybe a bit beyond) that was destroyed in a vaguely defined cataclysmic "end of the world" event. I'm very flexible about the nature of this event; my original idea was it was the typical last battle between good and evil and that evil won. I don't have any specifics plugged down. The races involved are fairly standard fantasy ones, mostly humans and elves. After the destruction, the intelligent races are essentially reduced to a hunter-gatherer state, and civilization has to develop all over again. However, I don't want there to be signs of the old civilization. At least, not everywhere. I don't want ruined buildings or skyscrapers, and I don't even want a plethora of dug up objects. Maybe a few items in isolated places, but I don't want this to be a major part of the actual story. Is this possible? Would it depend on how many years it's been since "the end of the world"? [Answer] Imagine a human culture that, instead of developing engineering around metal and stone structures, developed around shaping and using living materials. For example, large buildings could use a massive tree trunk as the central structure, with walls made of leaves, vines, hide, or canvas. Some features that would make this more possible / likely include: * Genetic engineering technology developed much earlier and more quickly. Or, the world happened to have plant species that were already closer to providing this functionality. * Civilizations tended to be more nomadic or migratory. For example, there could be seasonal or weather patterns that meant every part of the world was uninhabitable at certain times. * The natural resources required to build with metal or concrete were not easily available. * Due to evolution, cultural mores, or aesthetics, people strongly prefer flexible, biological types of structure. Furthermore, you could imagine that this culture made most of its artifacts from plant fibers rather than more durable materials like stone or hardwood. Or, if they're higher-tech, they might make them out of biodegradable polymers / plastics. This could be either for environmental reasons, or just a result of the chemistry of their natural resources. A civilization like this might not leave a lot of easily-recognizable artifacts or large structures. This would be especially true if the environment were prone to periodic fires. You would find remains in the same kinds of places we find well-preserved organic remains in our world: anoxic environments like tar pits (and landfills), or extremely dry ones like deserts. Another option would be to imagine a very high-tech civilization that has learned to create structures and hold together material objects using force fields. When their power sources go away, everything just falls apart. [Answer] **You can, but you'll need to answer the question of why there are no ruins.** Civilizations have a strong tendency to build lasting structures that later become ruins: so strong, in fact, that it's basically taken for granted by any culture with any awareness of history as a concept. The tribes might not be particularly historically-aware, but your readers will generally understand that history is a thing. So if there truly are no ruins, you need an answer as to why. **The ruins were destroyed**. The civilization left ruins, but some later force -an army, a monster, the gods, alien archaeologists, or whatever- destroyed or otherwise removed them. If you go down this route, you'll need to explain what this force was, and why it wanted to remove the ruins (if the concept of "want" even applies). **The ruins are somewhere else**. The events surrounding the fall of this civilization drove people far beyond the civilization's own geographic borders, and something has kept them away ever since. Widespread nuclear fallout is one possibility: to get to the ruins, people would have to venture for so long through highly-radioactive territory that they would die before ever reaching the ruins. Sunken cities are also popular: the ruins are at the bottom of the ocean, and the technology to get there is gone. That said, it is important that people die before even getting to the ruins. If they were to make it but die on the return trip, they might carry some evidence back a little closer to the tribes. Over several iterations of this, some bits might get far enough that a tribesman could venture in only a little way, find a piece, and survive to bring it back to his people. **People don't know that they're ruins**. In this scenario, the tribes live among the ruins, but don't understand them to be ruins. They think it's all a part of the natural order in a basically-untouched wilderness. This is good for civilizations that grew their raw materials, rather than mining or fabricating them, because it allows for the old structures to more easily change their form. **There was nothing to fall into ruin**. You could explore the difference between the concepts of "society" and "civilization" by creating an advanced society that did not "civilize" as we tend to think of it: there are no ruined structures because *they didn't build structures*. This may be the hardest one to pull off, because you have to explain how the society managed to achieve this level of advancement without the advantages that civilization brings. There is another thing to consider: it is hard to imagine that the advantages of civilization would never even occur to an advanced-but-noncivilized society, so you also have to explain why they did not take that path. **There was no society to begin with**. An alternative twist on the above would be to dispense with the society completely: they didn't build lasting structures because *they didn't exist*. But stories of them were written and shared, and these tales became popular as people found meaning in them, and so this metafictional society somehow managed to still have an impact on your fictional world. But this still leaves questions. Who thought of this civilization? How were the first stories written and shared? Why did they leave such a mark on the existing culture that the stories have endured for so long? Do people still understand that this civilization was fictional, or have the stories muddied so much over time that they believe it was real? [Answer] The irony here is that our modern infrastructure is far less durable than that of older civilisations. Unexpectedly this means (with a few exceptions) that the footprint of more advanced civilisations actually lasts for a shorter amount of time than some of the ancient ones. Let me give a few examples. * [Chernobyl](http://www.telegraph.co.uk/news/picturegalleries/worldnews/9128776/Photographs-of-Chernobyl-and-the-ghost-town-of-Pripyat-by-Michael-Day.html?frame=2161229) (25 years) * [Athens olymic park](http://www.theguardian.com/sport/gallery/2014/aug/13/abandoned-athens-olympic-2004-venues-10-years-on-in-pictures) (10 years) Obviously these both have a long way to go before they're reduced to dust but we're talking about less than a quarter of a century **with no human maintenance**. Modern construction materials often have a life expectancy of less than a hundred years (take a look at this [typical life expectancy chart](http://www.costmodelling.com/downloads/BuildingComponentLifeExpectancy.pdf) for building materials), even the foundations are only expected to last 110 years! Now, consider some of the greatest triumphs of the ancient world, look at [Machu Pichu](http://www.peru-machu-picchu.com/), the roman roads or [the great pyramids](http://discoveringegypt.com/pyramids-temples-of-egypt/pyramids-of-giza/). Even in more modern times buildings like the [Tower of London](http://www.visitlondon.com/things-to-do/place/22249-hm-tower-of-london) or [Edinburgh Castle](http://www.edinburghcastle.gov.uk/). The pyramids are around 4500 years old (there are some theories that the [sphinx is even older](http://en.wikipedia.org/wiki/Sphinx_water_erosion_hypothesis)). Why do these structures survive for thousands of years? Because they're constructed out of solid rock. The more modern the civilisation the greater the propensity for fast construction, this moves construction methods towards materials like steel, glass and concrete and away from more durable materials (hard wearing stone). As such removing all trace of a modern civilisation may take less time than you think, [this article](http://askwhy.co.uk/dinosauroids/?p=480) (which I don't source as a reference because it's simply someone else's speculation) suggests that there would be very little left after a thousand years. The beauty of this solution is that it doesn't require a planet wide disaster, your population could fall to plague and other life takes over in it's place. [Answer] Yes, it is possible. Civilization make structures in cost-effective way. And it means that the older civilization, the longer structure will stay. But when building these structures, only current danger is considered: * aging (materials get weakened over time) * impact (e.g. if constant flow of water will destroy very strong structures; or maybe some bomb) * misuse (when structure used in way that it is not supposed to be used) * lack of maintenance So your problem, is that you want to get rid of structures, that would stay for centuries (as you mentioned modern era). One way would be to introduce something that wasn't considered when these structures were built. Example for @octern suggestion of 'plant-structures'. If there was always summer, these structures could stay forever. But suddenly sun gone (or not that active anymore), and all plants died. For modern world it could be some alien bacteria that use cement as food or material for shell during reproduction. And then something else that will remove plastics/metal. As a result most of structures ruins will be consumed and no ruins left (to degree as you need). [Answer] There is always the "grey goo" option. Nanites are either deliberately or accidentally released that consume metal and plastic and replicate more of themselves. They sweep through the world taking out all technology. The economy, agriculture, and civilisation in question collapses, most people die either of starvation or fighting over what few resources remain. Large buildings collapse as the metal reinforcement is eaten. Over time the Nanites run out of fuel/resources to consume/etc and go inert. [Answer] Take a look at the Exterminatus in the Warhammer 40k Universe. If a Planet is to far from saving the Inquisition can order an Exterminatus.  Out of the four major methods of Exterminatus the orbital bombardment is the one likely to produce this result. The power of an orbital strike can range from small precision strikes, not unlike that of modern surface-to-surface missiles, to the unleashing of full thermonuclear blasts. Specalised munitions are used to control how much of the planet they destroy and are often tailored to particular planets. Often they can destroy cave systems as well as melting the surface of the planet. Alternatively a virus called the 'Life-Eater' can can destroy biological matter, produce flammable gas a a by product, followed by ignition. This produced fierce firestorms that scourge the world and are survivable by hiding in cave systems. I would estimate that about 50 - 100 years after the Exterminatus it may be possible for Life to start again. (Ashes mean that the world is fertile and the plants can repair the atmosphere) If you terraform it it would be about 10 - 50. It could be possible to survive such a process by hiding in deep caves or well designed bunkers; regardless, after the survivors are back on the surface they have nothing left. Note that in the Warhammer40k Lore it is not common to rebuild Worlds that are treated with an Exterminatus due to having the "Mark of Chaos". In my opinion with a few tweaks here and there and some valley where the organism could not reach before it was inflamed, or a bombardment that produced a concussive wave with less lethal radiation (so that some people, plants and animals survive) could be used as as a "clean new start". [Answer] Since your civilization is set back to hunter-gatherer, I think we can safely assume that the population is orders of magnitudes smaller than todays. This means that there can be a significant amount of structures left, but the population is nowhere near them, usually. To make this more plausible you might need reasons on why they keep away from previously inhabited areas (after all, people built megacities there because its a nice place to live). Reasons can be * Radiation from a nuclear war. Although people can not explain what it is, they get sick, so there are huge forbidden zones. * They are deserts now, and the only area where enough plants grow and animals live are near the poles, areas that are today rather sparsely inhabited. * Civilization has been buried under lots of ice, e.g. due to earths rotation axis/orientation being shifted, and what previously was hot is now cold and vv. * Tectonic movement forced lots of the coastline cities to submerge, while at other places huge amounts of ocean floor are now landmasses. This can even go so far as that the whole earth is just lots of islands now, that were previously mountains (where population density isn't that big) Also depending on the timeframe, you may consider fast growing plants (that might even have to do something with the initial cataclysm) grow over every building, and cover it; do that for a few decades or centuries, and you have a jungle on top of lots of hills, and only if someone digs a few meters deep, they would discover that the hills are really buildings. But there is probably no reason for your people to do that, so they will never notice, and for *them* it is a world without ruins. Also note that your people are probably around in that area for their whole life, so they won't probably go there and "hey, there is a ruin, lets explore that". It has been there the whole time, so it might be mentioned but I would not see a need for them to be a major part of the story. Take for example the via appica. In the past hundreds of years, not many living there would have said "hey, look, an ancient street, lets explore it and its origins". People had a life to live and probably cared much more about how to get food than what they are currently standing on. [Answer] Perhaps an Ice age after the civilization destroying event would be capable of destroying most if not all artifacts on the surface, however it would probably require 10,000 years or so for the ice to extend sufficiently far from the poles and retreat to allow civilization to reappear. Glaciers flowing across continents would essentially bulldoze anything and everything before them or crush them underneath. All concrete & stone surface buildings would be crushed, all artifacts of civilization such as cars, computers, plastic would be crushed and possibly pushed underground (as with glacial rock deposits on earth) or pushed to the ocean to lie on the bottom of the sea floor until discovered. Alternatively all civilization could simply be waiting at the bottom of an icesheet such as those in greenland and Antartica which are up to 3 miles thick! [Answer] **Later societies would scavenge the old ruins for materials.** If the ruins of the old civilization were made of useful materials, you might expect later people to strip them down for their own use. So many Roman structures were torn apart for their marble and metal fixtures during the Middle Ages. The limestone facings on the great pyramids were stripped off likewise. The only reason the pyramids still survive at all is because most of their mass wasn't worth removing. But imagine if our civilization collapsed. How valuable would large quantities of steel be after the fall? Skyscrapers would be torn apart for their metal. Consider how copper wiring disappears in decaying areas today -- it doesn't oxidize and wear away, it gets stolen for its raw material value. [Answer] It strikes me as possible but unlikely, if we're talking about more-or-less humans on a more-or-less Earth-like world, barring some of the catastrophic introductions suggested in other answers here (nanites, peculiar bacteria, etc.). If "civilization" has developed and then collapsed, presumably this means that multiple relatively large-scale cultures have developed. While it is certainly possible that one or more of these do not build much by way of structures, or build from perishable materials, surely it's unlikely that absolutely nobody is going to attempt long-term permanence in stone, worldwide. Think of Stonehenge and the Nazca lines: these are extraordinarily long-lived creations because they were done in the local permanent element. The reasons for making these probably are almost entirely unrelated, but nevertheless, people do tend to build stuff and it does tend to remain. There are ancient traces of ruins all over the world, created by vastly different groups of people in vastly different terrains. If you want to eliminate *every* possible "ruin," or trace of prior civilization, you either need an external catastrophe or a very, very long span of time. The earliest traces we have found date back something like 30,000 years (that's for cave paintings). I would suggest that the best way to eliminate every possible trace of human cultural constructions is a deliberate, systematic attempt -- probably by humans -- that for some reason lasted a good long time. Perhaps a sort of purge? That way nothing has to escape: once everybody just automatically destroys any traces they stumble on, as a matter of habit, it's not going to take all that long to wipe everything out. That's one of the things about humans: whether we are building or destroying, we are remarkably effective and permanent about it, all in all. [Answer] Another approach: They destroyed the relics. There's some alien race that doesn't like competition. They sent out killer space probes, their objective to destroy any other civilizations. A probe lands on a nearby moon and constructs a bombardment engine. It fires substantial rocks (say, kiloton range impacts) at any sign of civilization it can see. The locals quickly learn what it's doing and in any area that is to be a refuge they erase every indication of civilization they possibly can so they don't draw fire. Over time the refugees grew careless about keeping all tech items in deep caves and the caves drew fire/were sealed. [Answer] Time is a very important consideration. Consider this [Life after People](http://topdocumentaryfilms.com/life-after-people/) show where they explore how long it would take to remove the remnants of the human race. Another site, based on the [World without us](http://www.worldwithoutus.com/did_you_know.html) book by Alan Weisman, has a nice graphic that breaks down some of the different breakdown times. In 500 years suburbs would be forests strewn with plastic handles and stainless steel parts, But in the 10,200,000 years section it says that bronze sculpture would still be recognizable. You could also get creative with technology. A 'without a trace' technology could fill this need. Nature could also do this, laying down several layers over everything. Only by mining in certain areas would things appear from the past. [Answer] You mention the monsters coming from a "parallel world"? I am assuming here that you are talking about a parallel universe. If you want advanced buildings and society to neatly disappear, without having to have a specific degradable nature to them or without a huge period of time to pass, you could instead have the monsters responsible for their disappearance. These monsters from the parallel world, could be somehow transporting buildings to their own parallel world as part of an attack they produce. For example, whenever they slash their claws thru the air, they cause a rift between dimensions, briefly sucking things from this dimension into another dimension before the rift dissipates. An attack from these monsters could literally make cities disappear without a trace. Just an idea? Please be kind this is my first post here in worldbuilding! :) [Answer] Similar to Tim B's answer, the answer to your question can also explain why they were forced to devolve into a hunter-gatherer society. Simply tie the cataclysm into the building blocks of their society. Implying a large death toll and leaving survivors with minimal to no materials to continue. For example, basing all buildings and technology on a single element which ended up rapidly breaking down due to a reaction in the atmosphere. Buildings would crumble with people inside, devices would malfunction causing further fatalities, all that would be left is a handful of survivors with the only material they are knowledgeable of using no longer in existence. [Answer] Konstantin Petrukhnov's answer reminded me of the RingWorld civilisation written by Lary Nivel. This civilisation which had very high levels of technology fell because of a kind of mold (was it bacteria ? I don't remember) which ate basic component of very necessary machines such as the ones that brought energy to the RingWorld. Without electricity, the inhabitants reverted to less civilized ways of life. > > [...]The cause was a plague which destroyed the room-temperature superconductors which the City Builders used in their sophisticated machines, including the magnetic repellers levitating the floating buildings. > (<http://news.larryniven.net/concordance/main.asp?alpha=S#superconductorplague>) > > > Since *The Ringworld* deals with the discovery of an ancient technological civilisation, it could be relevant to you (if you haven't already read it, that is). To get back to the question, for it to be very few things left from the ancient civilization, it seems to me either a tremendous amount of time has passed (it takes time even for a all-eating bacteria/nanite to go through a whole world's surface), either a very sophisticated technology has been used to erase most of the infrastructures (and as a curious reader, I'd hate to be left in a blur regarding anything with that kind of effect, but that's just my opinion). [Answer] If the cataclysm was carried out by a willful entity (aliens, gods, a terrifically successful Luddite cult, mole people, whatever fits your story), as opposed to a dispassionate natural cause (meteors, earthquakes, plague) or an accidental one (level 5 biohazard containment got breached, CERN made a black hole, Doc Brown's fanboy treatment of a historical scientist distracted them from inventing steel), then it is a simple matter to declare that the same enemy that wiped out civilization intentionally cleansed the signs thereof, so as to impede what they had destroyed from springing right back up. [Answer] One way would be to do something similar to how Michael Moorcock ended the world of Melnibone' and the Young Kingdoms at the end of Stormbringer - and in a battle of the gods, it *really* doesn't matter who wins - the world will be toast (and since it'll be rebuilt by the victors, who get to write the history books or holy scrollery or whatever, I suspect that the ones who win will always be the "good" guys :-). Or, if you prefer something more scientific, either drop a 20-mile-diameter rock (this would pretty much bring civilization down, and if it killed enough critters it'd be a battle between evolution and plate tectonics, with evolution trying to raise up an intelligent race and plate tectonics relentlessly destroying all evidence of earlier civilization), or just torch off a nearby supernova (say, within 10 light years), which could potentially destroy most of life on earth. Best of luck! [Answer] # We destroyed our own ruins Remember the attitude of societies before our own: farmers looted Stonehenge and the Pyramids for construction material. Explorers burned mummies as fuel. Imagine if that attitude never went away. Ending is better than mending, out with the old, in with the new, and so on. Because of population pressure, we knock down all the old monuments, castles, and so forth, and build modern buildings. But the modern buildings are not designed to last long. Due to the speed of technological advancement, and the profitability of new construction rather than repair, humanity simply knocks down obsolete high-rises after some decades, and builds new ones in their place. As soon as some disaster prevents this renewal, the buildings start collapsing. Eventually all that’s left is rubble, worn down by weather over time. Winds would bring in dirt to cover the area. By the time your tribesmen find the place, it could still look like a barren patch of land, or it could already have life, but there would be no trace of the buildings that once stood, nor the rest of the world that was buried by their collapse. [Answer] A pretty simple way to leave no ruins: Have a nomadic civilization to start with. Nomads don't leave ruins, they might leave a few burial sites or gathering places, but not much else. Depending on technology you might need to deal with wrecks of some kind (or not, if you have some biological/genetic/symbiotic or even slave based economy and society). [Answer] Another thought comes to mind: Some reckless businessman is looking to use bacteria for metal recycling. Unfortunately, he's not careful about making something that's safe--the reason civilization was destroyed is the same reason there are almost no ruins: his metal-eating bugs got loose and survived in the wild. They ate the metals that make society run and it crashed hard. How much of society will be left once you strip the metals out? In time wood and plastic will burn. Almost all major buildings fall in the initial plague. We are pretty much down to concrete and asphalt being all that's left--and will your new population recognize the broken remains of either as artifacts of civilization rather than simply some type of rock? ]

[Question] [ **Setting** A world like ours, plus the usual magical [masquerade](https://tvtropes.org/pmwiki/pmwiki.php/Main/Masquerade), in an european capital (not decided which one yet). This is for a story following a few families, each with one type of powers. The members of one of them can create and alter objects. Their powers include duplication, repairing, random generation, etc. I would like for this family to make a living from these powers. My solution would be for them to own a store selling the objects they created. Maybe the most realistic would be some kind of second hand store or pawn shop. They could cook the books and actually buy stuff from time to time. **Problem** How difficult would it be for the owners of a store to hide from neighbors, clients and tax collectors that the majority of their wares comes from nowhere? Would it be realistic for this scheme to last for several generations? How far back in time can I make it go? English isn't my first language, please tell me if any clarification or correction is needed. [Answer] I've run a small retail store for over a decade. This is a complete non-issue. 1. Tax authorities don't care one whit for deliveries, nor vendors, nor for whatever accounting system you use. All they care about is that the books match the tax receipts that they are owed. Lots of legitimate non-magical business lack vendors and deliveries. Other investigators (like the Police) only get involved when a crime is alleged. And even then, they only look for evidence of the crime. They usually **don't** model the entire business workflow or cash flow. Note that in the USA, access to non-tax-related business records generally requires a search warrant, which in turn requires probable cause. 2. Nobody notices deliveries, and especially won't notice a lack of deliveries. I am also a nosy neighbor. There are shops adjacent to mine. In over a decade, I cannot recall any of them getting a delivery. Because deliveries, if any, are just part of the noise of daily life that everybody screens out. Maybe both got one yesterday, and I screened it out...and I pay attention to my street. I also don't notice the garbage trucks when my dumpster is not full. 3. Many inventories lacks a paper trail for completely legitimate and understandable reasons. Old inventory may pre-date the oldest retained records (normal records are NOT kept forever). Merchandise often lacks tags or labels. Invoices frequently lack insufficient detail ("*500 bowls*"). Bins of parts and small items may come from many different vendors. Success in business comes from tracking what is *important*, not from tracking *everything in pointless detail*. 4. Lots of legitimate, profitable businesses are not run in a way that you or I might consider "reasonable". That doesn't mean they are shady - they keep the required records for the required time, they pay their taxes, they don't defraud customers. That's really all the the law requires. They could be hopelessly mismanaged...but still legitimate and lawful. The family does not need a set of false books. They don't need sham deliveries. They don't need to trick, fool, or conceal anybody beyond what the plot requires. They are not doing anything wrong. Just don't lie on their taxes, and nobody will question or care. [Answer] This would be very easy to do, especially if they make legitimate purchases from time to time. They just have to be the right *kind* of purchase. Easier still would be to sell services as well as goods. **The right inventory sources:** If they buy things with unclear contents, it's harder to notice that the specific goods they sell are coming from nowhere. The antique store is a good idea. If they buy out old storage lockers, there won't be many people who could demonstrate that the inventory inside should not have included a bunch of specific items. If they deal in salvage (old shipwrecks, or other things that no longer have "owners" in a legal sense), it's also hard to prove that something they sell is something they didn't find. The family might have trouble buying enough things like this to sustain the illusion of a high-income shop over a long period of time, but that's another matter. **The right goods:** Some goods will be difficult to track by nature of what they are. Famous paintings are a good example: if a painting is stolen from a museum, owning that painting would be a risky proposition, and so a wealthy art collector with the right contacts might spend a lot of money on the painting but not be in a position to tell other people about it, or how they got it. If your magical family is... loose... with the law, they could potentially make copies of famous artworks and distribute them as though they were the originals. The buyers would have every reason to help keep the transactions secret (including covering up what they bought), but also would not be in a great position to discover that they'd been tricked into buying one of many copies. The actual business (well, in this case the front) wouldn't even need to engage in much commerce. Selling artwork can generate millions of Euros of income, enough to live on for long periods between sales. **Services:** Intangible services are really unclear in what they're "worth", and it can be difficult, or impossible, to prove that someone *didn't* receive one. If people "buy goods" but are officially charged for the service, you can inflate the cost of the service to make it less clear what inventory you're selling. A pop-culture example of this is > > The carwash used by Walter and Skylar White in a later season of *Breaking Bad*. Their problem was laundering money, but they sold regular car wash services, then recorded them as more expensive types of washes, and it would be very difficult to prove that someone *didn't* buy a deluxe wash five months ago. > > > That's a bit harder to mix physical goods with, but they can trade in goods while also hiding their actual inventory of those goods more easily that way. If we go back to the art dealer example from above, they could also provide vaguely defined "consulting" services. The cover story is not so important, as long as the amounts charged are reasonable. If someone buys a "rare" painting for one millions Euros, but it's billed as a professional inventory and art-preservation advising service, the actual sale of the painting won't show up on any records, and it will be hard to prove the "consulting" was worthless or non-existent. **Bespoke commissions:** There's no reason the things this family sells need to be mass-produced or generally available goods. A job where people request specific items be made, and those items require hard-to-value inputs like artistic skill or carpentry experience (for example), can do lots of inventory and value tricks. If they run a mostly normal business, but use magic to save on labor costs and time, they can make great money while still having a totally valid stream of raw inputs. Exactly how this works as a secret approach depends on the limits of the family's powers, but there are tons of ways that they could be more productive than a typical business when creating objects is magical. --- **How long could it go on?** As long as you want, really, and it gets easier the less money the shop has to make to keep up appearances. But there are easier ways to make a living with magic in the mix than running a secret shop for generations. Much easier would be to use the magic to generate a large amount of wealth, and then simply be a wealthy family indefinitely. Generating that wealth secretly would have most of the same problems as above, but it wouldn't have to be maintained for anywhere near as long. Once they have the money, and the money is clean enough to use, that's the end of questions. --- It is important to note, however, that because they are definitely *not* engaging in normal commerce they will never be able to have perfect camouflage. It might be very inconvenient to discover, and it might not even be discoverable without someone specifically looking for discrepancies and being lucky at the same time. There will be *something* abnormal about their business, or else they are just running a normal business, which in this case they specifically are not. [Answer] ## Layers and layers The key to maintaining a masquerade is to make use of other people's confirmation bias - that they are inclined to see what they expect to see and to readily accept that as "the explanation" for the state of things. People who go into a shop expect to see a place where they could buy stuff if they wanted to. A shop with nothing to sell, or only selling one thing, would be suspicious, but this is not that. As long as the items are there, and they can buy them in an 'innocent' way, they will be happy and unsuspicious. That means if the shop accepts credit cards, it should do so professionally and not make the customer uncomfortable; if it's the sort of shop where it would be reasonable for it to be cash-only, that's fine. Even people who live near a shop are unlikely to notice if the shop never received deliveries, because it's not really in their conscious. A pawn shop is a really great idea to further soothe the concerns of these observers, because even someone who watches the shop a lot can't tell the difference between a customer who enters the shop to buy something and one who enters to sell; the fact that rather than 50/50 the ratio is 100% buyers is not obvious or suspicious. To the tax authorities the same rules apply, except their 'view' is paper rather than physical. Cash-rich businesses like pawn shops are notoriously easy to 'cook the books' as cover for organised crime (or just ordinary tax avoidance), so *that's* what they will be looking for. Their suspicion is going to be that the goods that claim to have been sold never existed, and the recorded profits are actually just criminals handing over bundles of cash to be laundered into clean money for the shop's owners. You actually have the opposite subterfuge: you have *more* goods than you should have, and the money has come from genuine customers. The entries in the business ledger that will be fake are the payments out to suppliers for goods that do not really exist. Fortunately, as large companies like Apple and Google demonstrate, paying arbitrary amounts of money to other companies (under the same ultimate ownership) that are completely disproportionate to any real services provided, is not actually illegal or difficult, and it's devilishly hard for tax authorities to crack down on. [Answer] # Second hand shop If they claim they buy goods from other people and then sell them, there doesn't need to be proof of origin. In their records, you should just have something like: * date * description of item * how much the store paid for it Then they can "re-"sell the item. With the power of alteration, you could even create a bad looking item, take a picture and claim it was "restored" by the owners. Which will also justify a price increase. This *might* work as a charity shop. This will decrease the need of bookkeeping for received items - you don't need to "pay" any money for them. However, I bet the owners would be under increased scrutiny by charity organisations, so it might not be a good choice to avoid attention. Also, do *not* make this a pawn shop. Pawn shops' main business isn't selling second hand items but actually short-term money lending. The items are left as collateral to the credit. The credit business is even more noticeable by authorities than a charity. [Answer] It will be very easy to "stay under radar". It will be very hard to conceal irregular activities if an organization like FBI (with or without Fox Mulder) would start looking into things. Unless someone who's working in the shop will alert the authorities, or shop owners get involved into some real crime, there is very little chance that authorities would be bothered about the origin of merchandise. As other people already mentioned, authorities are concerned only that taxes are paid, and local ordinances are followed. If the shop is not taking on considerable amount of credit from banks, there will be no private audits either. Operations can continue for generations, and no one would suspect anything. On the other hand, it authorities are alerted to take a hard look into shop's operations, it would be very hard for it cover the tracks. It would become clear that either merchandise supply paperwork does not exist, or it is falsified. Shop owner still can get away by admitting their sloppiness and pay whatever fine that is required. But going forward with business as usual after that would be impossible. [Answer] While agreeing with [Kilisi's answer](https://worldbuilding.stackexchange.com/a/171186/586) in general, jewelry would be a bad choice. Jewelers keep track of gold and gems. It would be quite obvious in even a superficial view of accounts if the weight of gold sold were greater than the weight bought, leading to suspicions of melting down stolen jewelry. Instead, I suggest picking a craft with relatively low value inputs, difficulty matching output quantity to inputs, and substantial value added in the form of labor. An obvious example is ceramics. Bulk clay is cheap. Drying and firing reduces the weight, and there is always some waste. It would take careful analysis by an expert to find out if the quantity of clay, glazes, paints, and electricity for a kiln are enough for the quantity of product sold. There are several ways to make duplicated objects look hand made. The easiest is if their powers include altering finished objects. The family would need new designs as tastes change. If they offer their children clay to play with, and encourage any signs of talent, each generation or two will probably have a competent ceramic artist. A few instances of each candidate design go in the shop. If they sell, add that design to the regular duplication process. The main business expense will be salaries for family members working the shop or "making" the product. Keep those reasonable, in terms both of hourly rate and hours worked relative to product sold. The profits are divided among the family. Weaving would also work. The shop would sell hand woven rugs and decorative hangings. One advantage over ceramics is if they buy more thread than they actually use they can burn the surplus. Clay is harder to dispose of. [Answer] # Foreign shell company If they've been doing this a long time (generations as you say). It would be a small matter to set up an overseas company that "ships" the goods to the store. There could be a paper trail, and you could even have deliveries sent to the store from a warehouse and then shipped back again to the warehouse to create a paper trail and the image that things are actually going in and out. [Answer] User535733's answer is the most factually correct, but your issue is that your readers will be expecting the lack of deliveries to be an issue, so you still want to address it somehow. Your shop gets a small amount of deliveries and sells that, then sells duplicated merchandise the rest of the month as though it's all from the same shipment. Imagine paying for one box of lighters and selling the equivalent of five boxes. Much more profitable than a similar non-magical shop. Family finances would probably be enhanced quite a bit if they can duplicate food and other household necessities for themselves. This means they can survive on less profit than a typical family. [Answer] Your family deals in raw materials. Maybe at one point in history they were foresters who worked a patch of forest and produced firewood, mushrooms, lumber, animal skins, etc. Maybe at another point in history they acquired a mine and produce iron, or copper, or gold. In this way they don't have to explain where the excess comes from. The wood comes from the forest. The fish come from the sea. The gold comes from the mine. They just appear to be exceptionally good at producing those goods. [Answer] ### The Store Itself Looking at the store: * They have income from the items that they sell. * They incur expenses for all the other things that they normally would from operating -- wages, benefits, store upkeep, etc. * They are not against paying their fair share of taxes * They wish to avoid others prying into their affairs and practices. Those four points stated, as long as they fill out their paperwork properly there is no reason for them to really worry about it. They still claim revenue and expenses, and the difference between the two is the profit that is being made. Their only concern is being randomly chosen to be audited, and so long as they can prove that what they reported is true, they will not have issues from the tax authorities. If there is anyone to worry about, it is others in a similar business as without supplier expenses, they are making more profit than others in the same sphere of business. Business insiders will want to know the secrets to their higher profit margins and/or lower prices. The other main issue will be copyrights and how not to get sued by people whose things you have copied. If the store is stupidly selling copied iTech, then you can be sure somebody will look into them. This can be solved by making the original yourselves and copying that. ### The Masquerade and You In reality, the difficulty of their task is directly related to how far the Masquerade goes in your world. How far does the magical population infiltrate the normal world? Conversely, how many mundanes (or mostly mundanes) know about the supernatural and work to keep the masquerade? What effects are there to preserve it and how far do those effects travel from the source? If there are aware entities in the government content to allow it to stand, then there is little this family needs to worry about. They will not get randomly audited. If they do get audited, it will be by somebody aware of the supernatural that will understand why there are no stock intake receipts. If there is no support there, then they might set up a second business separate from the store that manufactures the items that are being sold by the store. Of course the same issues above now apply to this store, but instead of stock, it is the resources needed to make the things they are shipping out. Clients are not going to care about where you get the goods unless they have reason to be suspicious that they are not getting what they paid for or if they thing it is breaking their moral code. After all, the whole point of the Masquerade is that the mundane folk don't realize how your doing this. They will buy your wares so long as the price and service are up to their standards and you don't advertise that you sacrifice kittens to power the spells that create your goods. Neighbours are pretty much in the same space as clients in this regard. The only caveat with neighbours is that you don't do the magical things where the neighbours have a chance to see it. This means that there'd have to be some incredible spy efforts for a neighbour to find out you are conjuring copies of whatever it is this week. Overall, if they are careful about preserving the Masquerade as it is, then there should not be an issue with hiding your conjuring from others. That is possible to do for centuries as all that takes is a back room or basement to do your magic in that is away from prying eyes. ### Timelines This kind of thing could have been done for a long time. The exact methods used would evolve based on the world around them and the masquerade that is being upheld. The trick is to do what you can to alleviate suspicion that magic is going on. This also includes the family not magically copying things that will garner them attention -- currency coming to mind the most. [Answer] Simplest solution is to be your own supplier, buy raw product, perhaps gold from one family member in another country. Manufacture jewelry in the outlet. It could be anything, I just picked gold because it would be so easy. [Answer] An easy way to hide a magical ability like that is to use it to *inflate* your inventory. Run the store like any other normal store, buying your inventory through normal channels. When you take delivery of, say, 100 units of product, magically produce 5-6 more. Keep your "free" inventory a small-enough percentage of the total that it will be hard to detect and in the event someone *does* detect it, you can explain it away as rounding error or a typo in your ledgers. Alternatively, pose as a group of world-class craftsmen and run a repair shop. Advertise that you can repair or rebuild literally *anything* for the right price. People bring you stuff that's beyond any hope of repair, and in a couple of weeks you return it good as new (with a huge invoice attached, of course). You don't actually repair anything, you're simply destroying the original, magically creating a new one, and waiting a while to give the impression that you're actually doing work. [Answer] Unless everyone lives in the same house, there will still be vehicles arriving with the new merchandise, as they do for any other shop. Who knows or notices where they come from. Worst case, you hire a delivery van, fill it with empty boxes, and have a charade 'delivery ' of good every Monday morning. While being very secretive about your 'special supplier' because you don't want anyone else to be able to do business with them. [Answer] ## Multiple Shops Have 2 or 3 shops (maybe even more as business booms). Rotate where new merchandise is created (or even have a separate warehouse) and periodically ship items between shops. All the shops receive deliveries, so look legit, and redistribute the "items that aren't selling" periodically. This basically gives you a big shell game and as long as everything else remains on the up and up no one is going to investigate. [Answer] ## Frame challenge: Wait a minute, is it *illegal* to duplicate items like this in the first place? I mean, as long as you pay all the relevant taxes - where's the crime? You're not stealing, you're not cheating... Sure, there might be some limitations in place by law - like no duplicating of money or copyrighted works (hey, we have that already!) or smartcards or whatever - but besides that it sounds like a completely legal thing to do. In fact, this is a pretty overpowered thing, so there might be many people who would like access to this. Like, think what it could do to a countries nuclear weapons stockpile... Or even without the dystopian angle, I think the family would actually be able to make much more money by simply offering their duplication services as such rather than keeping it quiet and acting as a shop. ]

[Question] [ I would like to better understand intragalactic ship design (aka, "spaceships"). * It's travelling at a barely tolerable 0.05c (86 years to Alpha Centauri). * It happens to impact with a baseball (145 grams). *(In reality it would impact with rocks. We believe there's nothing out there other than inconsequential dust, but the reality is we don't know because we can't detect anything this small, so assume I'm right, please.)* * Maximum material thickness: 100 cm. * For the purposes of this question, whether or not the material will be dented is ignored, so long as it is not pierced or burned away. I believe the basic equation is Joules = 0.5 \* mass(Kg) \* velocity(m/s)2. In which case, the baseball hit my ship with 16 TJ of energy. **Question** Is there a material today that could act as the forward plating of my ship that could withstand such an impact? [Answer] > >  Is there a material today that could act as the forward plating of my ship that could withstand such an impact? > > > The problem is the same with the rock hitting the ship while the former is traveling at .05c and the latter is standing still. We may use [Newton's impact depth equation](https://en.wikipedia.org/wiki/Impact_depth#Newton%27s_approximation_for_the_impact_depth) giving penetration depth of a projectile P in a shield S, $depth = length\_P \frac{density\_P}{density\_S}$: at that speed, the barrier will act as a liquid and the rock, having a length of 5 cm and [a typical density of 3.5 g/cm^3](http://meteorites.wustl.edu/id/density.htm), will penetrate to a depth of about 17.5 cm in water (this excludes penetration-optimized shapes). At that point it will have ceded all its considerable momentum to the surrounding material, converting a significant fraction of it into compressive and friction heat, and it will explode. In the volume of impact a *plasma jet* will form, still possessing a considerable momentum, and will start penetrating inwards; since the elementary momentum is given by the product of density by speed, and it is a finite quantity, the greater the density the lesser the speed. So you want to have the densest possible material (which would be osmium, density of around 22) for the first 20-25 cm, then you need to survive the explosion of ~240 tons of TNT and temperatures briefly in excess of several hundred thousand K, *plus* the jet of osmium plasma that has absorbed the momentum of the impactor. This calls for some superrefrigerated phase-changing metamaterial (mostly [ice-XI](https://en.wikipedia.org/wiki/Ice_XI)) and some way of distributing the impact laterally as quickly as possible, which calls for an enormous Young's modulus - basically a [carbyne layer](https://en.wikipedia.org/wiki/Linear_acetylenic_carbon). Finally you need to consider [spallation](https://en.wikipedia.org/wiki/Spall). The shock wave will travel through the armor, and blast the opposite side even if the projectile doesn't push all the way through. You need a further layer of high density, high tensile material to block *that*. I'm not too sure that all of *that* is going to fit in a 100cm thickness... # We overlooked something! The thickness of 100cm refers to an impactor hitting **head on**. But if we build the shield as a sloped, conical glacis - a *vacuodynamic* shape - we reap some very important benefits: * the collision will be **at an angle**, thereby wasting a large part of its energy into a shower of fragments taking away most of the momentum harmlessly. * the penetration path will be increased by the inverse sine of the slope angle; an angle of 30° will immediately double the thickness of the material as seen by the impactor. I think we can do this! :-) # Charged Whipple shield A standard Whipple shield will probably not fare well against solid objects in the hundred-gram range. But we can imagine a cubic lattice of osmium pellets connected by very strong **insulating** threads (e.g. Kevlar) no more than three or four centimeters long horizontally, and a dozen meters vertically; the lattice itself is as wide as the ship's front. At takeoff, the lattice is folded and is only some centimeters thick. Then we start pumping electric charge into it (somehow). Coulomb repulsion starts driving the pellets away one from the other, until they form several layers of four-centimeter square mesh, separated by a dozen meters of empty space. When the charge is high enough, the lattice becomes increasingly rigid. Now a 5-cm rock comes in at .05c relative speed. It impacts on one, possibly two pellets of the first layer, and explodes, forming a cone of debris still traveling at .05c. It has also absorbed a lot of electric charge, and therefore each debris particle is strongly repelled by all the others - which contributes to the cone's expansion - and by the incoming subsequent layers, which both expands the cone and slows it down. We can't pack 16 TJ of Coulombian potential in one hundred twenty meters' worth of lattice ([or can we](http://www.phys.ufl.edu/%7Eacosta/phy2061/lectures/ElectricPotential.pdf)?), as the lattice would start discharging by emitting charges into space faster than we could replace them, but sure we can make it behave like a sort of [electric reactive armor](https://en.wikipedia.org/wiki/Reactive_armour#Electric_reactive_armour). In the end, the final layer of the shield only needs to be able to deal with small-size buckshot; a layered sandwich of high-density material to absorb momentum, high-tensile material to diffuse the shock and vacuum to stop P-waves will suffice. When slowing down at arrival, the lattice is powered down and folded back. It's true that the *total installed thickness* is two orders of magnitude greater than your requirement of 100cm, but its *equivalent* thickness might well fall under that. # Protecting against impactors Protecting against impact will resemble that game called *Missile Defense*, with the impactors arriving at a relative .05c. [](https://i.stack.imgur.com/KQbQD.jpg) But you cannot use *missiles*. What you do is saturate the space in front of the ship with [millimetric radar](https://en.wikipedia.org/wiki/Extremely_high_frequency), which will give you a low-noise estimate of the incoming impactors and something about their nature. It's reasonable to expect detection at about 500-600 kilometers, maybe more (high vacuum, few disturbances). You will use *several* radars to immediately gauge position and speed of incoming projectiles through parallax and Doppler shift (and also for redundancy). At 500 km distance traveling at .05c you have a warning time of about **30 milliseconds**. You can't safely swing a weapon mount in that time. So you use a massive [*phased laser array*](https://en.wikipedia.org/wiki/Phased-array_optics) instead, to direct the equivalent of a focused megawatt of power from a supercapacitor bank into the rock, which can be expected to shatter. This robs the inbound projectile of perhaps one percent of its energy, but importantly it reduces its size, and penetration is proportional to that. It also weakens its structure, increasing the chances that a glancing impact will remain just that - a glancing impact. At the same time, the relative speed imparted to the impactor will be directed towards making the impact angle *shallower*, further reducing the damage. If there's enough time, supplemental strikes could further reduce the damage by pulverizing the most threatening fragments. [Answer] You're going at this wrong. Your defense material is aluminum foil or something of the sort. Once your ship is up to your .05c you spread out a sheet of aluminum foil and push it ahead of you. Periodically launch another one. You're no doubt saying the the baseball will go right through and all but ignore it. Here on Earth that would be true, but look back at the energy of your impact. It's not 16TJ because for practical purposes it's the aluminum foil hitting the baseball. It's still a **lot** of energy, though. Yes, the baseball is hardly slowed by this--but it is vaporized. You now have a very rapidly expanding ball of plasma. That's much easier to stop and very well might be dealt with by subsequent sheets and certainly can be stopped by your hull--it's just a dense pocket of pretty low energy radiation at that point. I've also seen dust suggested for a similar use but it's much harder for the engineering department to verify the protection offered by their shield that way. [Answer] # Unlikely, but it doesn't necessarily need to Existing spacecraft don't need to deal with relativistic speeds, but they still move incredibly fast. And while satellite-destroying meteors are rare, micrometeors are pretty common. A meter of shielding is far beyond the budgets of any spacecraft we currently build. Instead of trying to use thick solid shields, modern spacecraft rely on [Whipple Shielding](https://en.wikipedia.org/wiki/Whipple_shield). A Whipple Shield is a spaced shield - it has two layers with a gap between them. The first layer intercepts obstacles, but it isn't intended to stop them - its purpose is to disperse the energy over a larger area. [](https://i.stack.imgur.com/fREdJ.png) Even as the first layer gets perforated, the holes are small and don't significantly compromise the layer's structural integrity. The second layer isn't penetrated by the more diffuse impact, and maintains an airtight seal. There are, of course, many variations on the design that Fred Whipple proposed in 1946. You can use more than just two layers - that way if the energy is not sufficiently dispersed by the first impact, it can be dispersed several more times before risking your final layer. You can use flexible materials such as Kevlar instead of rigid aluminum. But the basic principles remain the same. By using multiple layers separated by gaps you disperse the impacting energy and make it possible to protect your ship with a great deal less shielding than you would need with a solid shield. [Answer] Your goal is to let this hypothetical material dissipate 16 TJ with just 1 cubic meter of material per square meter of impacted surface. That amount of energy is comparable to 1 kiloton of TNT: smaller than Little Boy, but still quite a lot. If you want to stay compact (meaning few square meters of shield surface) I think there is no material which can fit your purpose. P.s. the formula for the relativistic kinetic energy is $$E\_k = m\gamma c^2 - mc^2 = \frac{mc^2}{\sqrt{1 - v^2/c^2}} - mc^2$$ [Answer] There isn't. The energy will make any solid act like a viscous liquid - doesn't matter what the material is. The practical way of passive defense is [Whipple shields](https://en.wikipedia.org/wiki/Whipple_shield) - multiple layers of material with a lot of spacing. The layers explode the impactor plus the shield into pellets, spacing lets the pellets spread out, each successive layer of material spreads them into smaller pellets. So there are optimal layer and spacing thicknesses. Any Whipple shield is inferior to a solid block per unit depth, but superior per unit weight. Very roughly, a single shield layer with mass loss matching the penetrator's mass should halve its effective energy. So, at 0.15c, and at 1 km/s as tolerable impact for the final armor, you should be looking at 31 layers. Given your geometric parameters, ~0.02 m^2 initial impact area can be counted on, so you need a 7.2 kg/m^2 density per layer. In other words, 3 mm aluminum. Add 200+ mm behind each layer and stack 31+ such layers before your main armor, and you should be covered. I's more than 1m geometric thickness, but it's just 100mm of total material thickness, plus whatever it takes for the final armor to stop 1 km/s impact. The main armor is subject to conventional mechanics and just another 100mm would do. But 1m of ceramic and metal would not be unreasonable for the front of a large colony ship. [Answer] The easiest seems to be to destroy the rock before it hits the ship. Once the ship has reached cruise speed, the engines are stopped, and it now travels at constant speed. At this point you need to spray a fine mist of water, or perhaps dust, in front of the ship, and let it expand until it fills a sufficient volume. It can't be a gas, as it would expand very quickly (unless the ship is heavy enough to have its own atmosphere). I'm not sure water droplets would stay solid and not sublimate, I'd rather use dust, ie small solid particles. Feel free to pick the material you want. Perhaps the dust cloud can be held into a useful shape by using magnetic and electrostatic fields, if the ship has its own magnetic field, a bit like the Van Allen belt... Now, if your baseball sized rock enters a cloud of dust (or gas) at relativistic speed it will be vaporized almost instantly, and it will turn into expanding plasma. The advantage a cloud has over an aluminium foil as suggested above is that the more the plasma expands, the more material it will encounter, which will spread it even more. Hopefully it spreads over a wide enough area to bring the energy density per square meter down to a manageable value for the hull of your ship. Also a significant proportion of the kinetic energy would be turned into radiation (ie, light) and radiated in all directions (thus only a very small proportion would hit the ship). Another advantage relative to the aluminium foil is that the foil isn't see-through. [Answer] **Dark matter.** [Dark matter might not be interactive after all](https://phys.org/news/2018-04-dark-interactive.html) Dark matter interacts with other matter only via gravity and with electromagnetic radiation not at all. So far no-one has been able to detect an impact from a particle of dark matter on a particle of normal matter. It may be phantomlike, passing through normal matter without a touch. But for slowing a fast moving object, gravity works great. Your baseball will pass through your front shield of dark matter and be slowed gravitationally after it passes the halfway point, where the net gravitational pull is the opposite of the moving ball's momentum. Eventually it will be slowed to a stop. This will require a tremendous amount of dark matter and it will be tricky to contain any amount of a substance interested only in gravity - hopefully your future tech includes artificial gravity. Fortunately there is apparently a tremendous amount of dark matter for the taking, and the OP only requires "withstand"; once in place your planet-sized chunk of dark matter will be impervious to impacts of any sort and good for the duration. A big question and one I cannot find an answer for - what happens to the energy of the baseball decelerating into dark matter? If normal matter falls towards a black hole, gravitational potential energy is converted to heat and shed as radiation. If dark matter can fall under gravity but is unable to shed energy as radiation, what happens to that potential energy? Does dark matter get irreversibly hotter? For your question it is a little easier because the baseball can get hotter and certainly will, dissolving into plasma long before its momentum has ceased. [Answer] In one of the Star Trek books, the author describes the crew trying to figure out how to destroy a planet-sized machine, at all cost. One idea is to accelerate the ship to close to light speed and ram. Computer analysis determines (according to the author) that the outcome would be a Startrek sized hole going straight through the planet, with not much actual impact. Maybe the same would happen with a baseball or rock at 0.05c: If you don't try any shielding, it might just go straight through the ship and leave a baseball sized hole. You might just accept the possibility, make sure that you can fix any air leaks very, very quickly and hope you can repair the damage. [Answer] Maybe Neutronium? It's 4 \* 10^17 kg/m^3... 13 magnitudes denser than anything else. Only problem is keeping it that dense. --- Or maybe use black holes as shields, to just absorb the impactor, but a baseball-sized black hole, is already too big to be useful, as its gravitational effect affects the movement of the ship too much to compensate for. --- And both of those methods are out of reach of current science, while possibly being the only things that could withstand the impact you're subjecting the spaceship to. [Answer] In extremely high energy cases like this, the Newton penetration equation applies. The amount of energy spent accelerating the target material out of the way will greatly overshadow any contribution by strength. Newton's penetration equation is - penetration depth (s) = (density of projectile / density of target material) \* length of projectile. For a 400 kg/m^3 leather baseball about 0.15 m in diameter impacting some 8000 kg/m^3 steel, the depth of the impact crater in the target material would be 0.008 meters. For a 1000 kg/m^3 ice cube also 0.15 m long, the impact crater would be about 0.02 m deep. i think the takeaway is that anything not close in size and mass to your ship will be annihalated. However, your hull will get eaten away over time by these collisions. Although its a popular device, force fields would have to be terrifically powerful, as you have already calculated, to produce the same benefit as a sheet of lead or steel. ]

[Question] [ I'm working on a hypothetical political system similar to a monarchy except that the (conscripted) king in question is essentially a slave to the nation, a very well-cared for slave but with no personal freedom. The idea behind this is to prevent corruption by ensuring the king has no personal bias, no conflicts of interest, that they (can be he or she, gender isn't relevant) cannot be bribed or extorted. This is achieved by preventing the king from having interpersonal relationships of any kind (no friends, family or lovers), ensuring all of their needs are completely catered for and that they are almost completely isolated from society's influence. Orphaned infants are raised separately by highly trained carers wearing full body covering form-concealing clothing, scent concealing perfume, full-face masks, and they all move in the same highly ritualized way. These carers are on a rotating roster so even if a child managed to identify one they would see that one so seldom that they wouldn't be able to form any personal attachment. Instead, they're encouraged to interact with all carers as though they were the same person, specifically a characterized mother figure that represents the nation itself raising and caring for them. As the orphans grow up they're schooled with a particular focus on history, philosophy and political theory. When they come of age the current king is disposed of (kings are replaced every 20 years or so) and the orphan who is deemed to have the best disposition and aptitude for the role is ordained to be the new king, after a year or two without the new king showing instability the other candidates are deemed unnecessary and disposed of. While in office the king has absolute power insofar as it doesn't interfere with the mechanisms of succession nor result in the king interacting directly with anyone but the carers, who now also act as administrative assistants. How feasible do you think this system is and what problems do you foresee it having? [Answer] > > Orphaned infants are raised separately by highly trained carers wearing full body covering form-concealing clothing, scent concealing perfume, full-face masks, and they all move in the same highly ritualized way. > > > Let's just assume for the sake of argument that the children would still be psychologically well adjusted and basically functional, despite having never seen a human face during their childhood. I actually think that's rather open to debate, but it is difficult to prove one way or the other within the constraints of academic ethics. > > As the orphans grow up they're schooled with a particular focus on history, philosophy and political theory. > > > These subjects are all highly open to partisanship and outright bias. It will be extremely difficult to design these courses in a neutral fashion. > > When they come of age the current king is disposed of (kings are replaced every 20yrs or so) > > > Presumably the old monarch just... retires in seclusion? What happens if the monarch refuses to relinquish the throne? Are they violently removed? > > and the orphan who is deemed to have the best disposition and aptitude for the role is ordained to be the new king > > > Deemed by whom? What are the selection criteria, exactly, and who makes this call? It can't be the previous monarch, because you (maybe) just violently removed them from the palace. > > after a year or two without the new king showing instability the other candidates are deemed unnecessary and disposed of. > > > * How is "instability" defined? Would (for example) President Trump qualify as "unstable?" Who makes this decision, and on what basis? * Is "disposed of" a polite euphemism for "executed?" If some supposed orphan really has a pair of long-lost parents, they are going to move heaven and earth to protect the life of their child. You could have any number of "overthrow the evil regime" stories come out of that setup. > > While in office so to speak the king has absolute power insofar as it doesn't interfere with the mechanisms of succession nor result in the king interacting directly with anyone but the carers, who now also act as administrative assistants. > > > There are two separate singular points of failure in this system: * The monarch could make any number of poor choices notwithstanding their isolation. Isolation and neutrality do not guarantee a superior decision-making process. There are numerous well documented cognitive biases which have nothing to do with personal attachments. Particularly relevant to a monarch or ruler are [scope insensitivity](https://en.wikipedia.org/wiki/Scope_neglect), [the availability heuristic](https://en.wikipedia.org/wiki/Availability_heuristic), and the [just-world hypothesis](https://en.wikipedia.org/wiki/Just-world_hypothesis), but there are [numerous others](https://en.wikipedia.org/wiki/Category:Cognitive_biases). While there are certainly biases associated with personal attachments, many other biases are likely to be exacerbated by the monarch being isolated and detached from the decisions they are making. Fundamentally, your monarch cannot properly empathize with the people they are ruling. * The carers are the actual rulers in this setup. When some decision needs to be made, the carers are briefed on it, they brief the monarch, the monarch makes a decision, and the carers relay it back to whoever is in charge of executing the monarch's decision. There is no mechanism by which you verify that the carers provide the monarch with a neutral, factual summary of the issue. In fact, there is no mechanism by which you require the carers to communicate with the monarch at all. They could simply reach a decision by themselves, assure the monarch that everything is "fine," and relay their own decision as if it had come from the monarch. Even if they do not deliberately subvert your system of government, they will surely introduce bias and political opinion while talking with the monarch. If they just read a summary from a piece of parchment, then whoever wrote the summary will introduce bias instead. + For a fictional example of "carers" taking control of a monarchy in this fashion, see the second season of *Avatar: The Last Airbender*. In it, the Earth King has no idea that his country had been at war for nearly a century, because the Dai Li never told him. --- **In conclusion**: This is at best a wildly impractical system of government, and is unlikely to provide enough stability to outweigh the cost of the carers, the infants, etc. In your description, I also noticed a repeated tendency to neglect to specify how decisions are made and who is responsible for them. Any "real" system of government needs that spelled out, especially for decisions which are genuinely ambiguous or difficult. [Answer] This way madness lies. > > I'm working on a hypothetical political system similar to a monarchy except that the (conscripted) king in question is essentially a slave to the nation, > > > The word "democracy" leaps to mind. :-) > > a very well cared for slave but they have no personal freedom. > > > Kurosawa's *[Kagemusha](https://en.wikipedia.org/wiki/Kagemusha)* sounds like this. > > The idea behind this is to prevent corruption > > > Impossible. > > by ensuring the king has no personal bias, no conflicts of interest, that he (or she, gender isn't relevant) cannot be bribed or extorted. > > > A normal all-powerful monarch would have no conflict of interest (just their own interests), could not be bribed (they own everything already) or extorted (try blackmailing someone who can have you killed very slowly with a nod). You also seem to think that being corrupted or bribed comes only from within the person. This is quite wrong: pressure and manipulation from other people will corrupt someone - it's the basis of all politics. Personal bias cannot be eliminated. You would need to eliminate the person. Over time, no matter how neutral they start out, they would inevitably develop a bias in some way or other. > > This is achieved by preventing the king from having interpersonal relationships of any kind (no friends, family or lovers), ensuring all of his/her needs are completely catered for and that he/she is almost completely isolated from society's influence. > > > What you are describing is a type of [dehumanization](https://en.wikipedia.org/wiki/Dehumanization). Humans have been placed in prisons like that before - they go mad. It's not possible for a social animal like a normal human to survive without some (or many) mental problems caused by isolation. When prisons want to punish prisoners experience has taught us that completely isolating them will have a terrible effect on any but the most unusual (and not necessarily normal) people. For sane people *all of his or her needs* includes companionship and warmth which you're excluding. While many people can manage celibacy, the idea of no friends or family is one that would result in a psychological disaster. The worst prisons have not been the ones where physical abuse is practiced, but the complete isolation from others - it is a torture that robs the soul. > > Orphaned infants are raised separately by highly trained carers wearing full body covering form-concealing clothing, scent concealing perfume, full-face masks, and they all move in the same highly ritualized way. These carers are on a rotating roster so even if a child managed to identify one they would see that one so seldom that they wouldn't be able to form any personal attachment. Instead, they're encouraged to interact with all carers as though they were the same person, specifically a characterized mother figure that represents the nation itself raising and caring for them. > > > Dehumanization again. The worst aspect of this (from your point of view, although not from that of the poor sod who has to suffer it) is that your individual will develop no sense of *empathy* with other people. Empathy is not something you get without exposure to seeing how your action affect others (and in particular how your cruelty can cause them suffering). So your ideal ruler will no interest or empathy for his country or the people in it. They would simply rule by decree in an isolated and abstract world which they do not understand. > > As the orphans grow up they're schooled with a particular focus on history, philosophy and political theory. When they come of age the current king is disposed of (kings are replaced every 20yrs or so) and the orphan who is deemed to have the best disposition and aptitude for the role is ordained to be the new king, after a year or two without the new king showing instability the other candidates are deemed unnecessary and disposed of. > > > Wow, that's so naive. Real world : Either the monarch spots that his position is not guaranteed and they're not safe (what does "disposed of" mean ??) or someone else in court who is crafty decides they're going to mount a coup d'etat and control the puppet monarch themselves. As you've taught the monarch all this political science stuff they're going to be well grounded in how conspiracies work and how to get stuff done. So in short order, this monarch, one way or another, will gather a solid and entirely loyal group of personal attendants (the expression "Praetorian Guard" comes to mind). Once everyone close by is controlled by fear, money or apathy (and apathy is a real concern as in your system it effectively makes no difference *to them* who is in charge), then the expert politician will rapidly move to take over all power. And in the process say goodbye to their days as a lonely, loverless, friendless prisoner. And flay alive the b\*rst\*rds who made the monarch suffer that in the first place. What your process will create, in fact, is a ruthless individual skilled in manipulating others and political machinations with a huge self-interest in changing things to suit their own needs and no interest or empathy at all in the lives of others. You've made Stalin, or Hitler or maybe Genghis Khan. Congratulations. [Answer] Let's assume for the moment that the carers are absolutely dedicated to this concept. That's questionable, but let's just assume that works. Somehow. You now have a monarch who doesn't care a fig about any real person. In fact, your monarch probably doesn't even view people as real, just as characters in stories told by the carers. A classic, possibly apocryphal, quote is "Let them eat cake." The basic idea is that that royal's world view was so different from that of the ruled, that she simply didn't understand that a lack of flour would prevent the cooking of cake as well as bread. Your royal would have the same problem. There would be absolutely no connection between her or his experiences and those of everyone else. Even if we assume that this system is corruption free, which is again questionable, the price is terrible. This ruler would have no reason to hesitate against an order like "kill all the [minority] people so that we achieve racial homogeneity". You can control this a bit by asking the candidates to comment on various hypothetical situations. But that leaves you vulnerable to the other problem. Perhaps the monarch is insufficiently aggressive in addressing problems. So rather than taking aggressive action, the monarch just sort of lets things slide. People are starving? They should asks their carers for more food. Food theft is rampant? The monarch suggests that people should stop hoarding food and eat it immediately. Or the monarch might find the work of governing dreary. Instead of listening to the problems or reading the reports, the monarch goes swimming. Or the monarch decides to do some experimenting. What if the punishment for food theft were butchery? Kill the thieves, butcher them up, and distribute the meat to the victims. An elegant solution...for a sociopath. People refuse to turn cannibal? Take them off the food distribution list. Clearly they aren't hungry enough. And those who do go cannibal? Maybe some of them like the taste and want to continue with it after the current emergency. What if the soldiers don't enforce the food theft rules? Or they all quit as soon as the current crisis is over? Or they mutiny in the middle? How does the monarch enforce things without popular support? And how will a monarch who effectively knows no one attempt to get popular support? This seems like the kind of system that would work for a generation or two and then fail spectacularly. [Answer] This system actually makes the carers the supreme rulers of your country and the king their puppet. * They are the people the kings form a bond with during their formative years, which means that the kings will be loyal to them. * They decide what history, philosophy and political theory the young princes get exposed to and how that information is framed, thus shaping their future governing style to their needs. * They decide which prince is deemed to have the best disposition and aptitude for the role of king, which for them means they pick whoever is the most indoctrinated and the easiest to control. * Should the new king not perform according to the goals of the carers, they can declare that the king is "showing instability" and replace him. * Should that be too much work or should they miss the 1-2 year mark which allows them to do that, they will also have an easy time manipulating the king. The carers are also the administrative assistants of the king, so they filter the information the king receives and they relay the king's orders. That will make it easy for them to ensure the king makes the right decisions, and when he doesn't they can just give the royal edicts some "minor editorial revisions" before they publish them so they say something completely different. So bottom line: If I wanted something from your government, I wouldn't even care about your king. Tell me more about how you select and educate the carers and how I can corrupt *them* to support my agenda. Do they prefer their bribes in form of power, pleasure or cash? Which of their secrets would they want exposed the least? Which family members would they miss the most if something happened to them? [Answer] # The system won't work What motivates every system is that somewhere in the difficult jobs of ruling and caring for the country, is someone benefiting personally from it. This is where the corruption comes in but you seem to only have thought a little way down from the king. There could but corrupt carers but you cover this [in a comment by giving them supervisors](https://worldbuilding.stackexchange.com/questions/102403/feasiblity-of-this-slave-king-political-system#comment307515_102404) but who supervises the supervisors? There would be a hierarchy within the supervisors (or their supervisors) because *every* system needs orders. Wherever you have a hierarchy you'll have a 'king' thats at the top. The switching of a king will, naturally, bring instability and anyone who might lose from that will seek to alter the system somehow to their benefit. The main problem (with the rules) is: > > While in office the king has absolute power insofar as it doesn't interfere with the mechanisms of succession nor result in the king interacting directly with anyone but the carers > > > Who enforces this? What is their motivation for doing so? # *All* your kings will be unstable Childhood development and lack of emotional attention has been well studied and, as the [Scientific American](https://www.scientificamerican.com/article/infant-touch/) says: > > Many children who have not had ample physical and emotional attention are at **higher risk for behavioral, emotional and social problems as they grow up**. > > > I mean, not the people I think should be ruling a country. How would they have developed empathy or even a concept of people, other than themselves, having any needs at all? (No, they won't learn it in a philosophy book if they've no frame of reference). [Answer] Let me throw an alternative view of this into the... thing... - How about a kind of futuristic setting? That way the king has access to all the knowledge, info, stats, etc. that he needs through a computer interface. In fact it's like he's playing a very slow, detailed and complex version of "Sim City", but his decisions are carried out in real life and the effects fed back into the system/game/whatever you want to call it. His entire purpose in life is to do as well as possible. This takes away the idea that the carers are in fact the real rulers to a certain point. In fact, he can even be trained on highly advanced simulators (Sim Sim City?), and learn from his predecessors by watching recordings of their play - what they did and the effects they had. Also, everything the carers say and do to him is recorded to try and reduce corruption. (Except in cases where national security is a factor, of course). Furthermore, none of the carers are allowed to interact with each other, to prevent them from conspiring against him. There could be some sort of futuristic psychology/brainwashing in his training to make him truly motivated to do as well as possible. Of course it's still open to corruption. The system could be hacked to give him a better score if he enacts certain policies that would benefit the hackers. And I'm sure it has lots of other pitfalls that I haven't thought of that would become obvious when this is done in practice - but then, so has communism! (And fascists/communists would argue, so has democracy/capitalism!) [Answer] ## Welcome to your psycho-king-empire! Yep, to say it frank: the education process of the priancess creates just one type of people: psychopaths. They learn no empathy, they learn never that there are other people to care about, when thy hit puberty most will become sexually frustrated and in the end, they are all masters of disguising their brken core with a cold shell to the caretakers... And then you put these monsters in cold disguise on the throne. It takes only one of them to get over the safety time to bring down the empire. And with the rate that these princes have to be churned out, there will be one such cold-psycho king that just waits... and then breaks the whole system down because of his mmadness. He might just decree - for his own amusement - that all caretakers be shot in front of him, because he has a grudge against one of them. He might have all the other princes hanged and no new ones trained because he feels nobody should go through that - or because he simply likes where he is. He might g fully bonkers and demand that he is not a human but a god and all people should come before him and perform ritualistic suicide so he can bath in their blood so they will be enlightened... I can't forsee HOW the one needed psycho-king will break it all, but he **will**. Even Nero had had more bonds to humanity than these kings. ## Friend Computer There is however one way this empire works: kick out the replacement system. Make the king all powerful... and a Computer. Replace caretakers with programmers... and voila! Welcome in the Alpha Complex of Paranoia. Because Freind Computer may be a psycho, but he is a *friendly* psycho that can be *fixed*. > > Voting is mandatory citizen. Failing to vote is treason. Voting for the wrong thing is treason. Are you a traitor citizen? > > > Friend Computer, Edict 914212 > > > [Answer] Question: What do Plato's Republic, the Ottoman Empire, and Harry Harlow have in common? Answer: Your idea. In [Plato's Republic](https://en.wikipedia.org/wiki/Republic_(Plato)), he envisaged society ruled by a caste of philosopher kings bred and raised to be morally superior. Their basic needs were provided for, but they were forbidden from owning private property. Couples were selected for reproductive reasons and the family is abolished, they would share wives and children. He imagined this combination of breeding and education, along with ensuring this caste was meritocratic, neither in want nor spoiled, would make them excellent rulers. Plato's republic has the advantage over your system that there's no distinction between the carers and the rulers, and they become a group something alike the modern day Saudi royal family in terms of scale - thousands of eligible rulers who presumably would work at various levels of the civil service to ensure the orders from the top were followed and well advised. Your point about bringing up infants in a sterile environment without any real intimacy or contact with other humans however will kill them. I suggest reading about [Harry Harlow's](https://en.wikipedia.org/wiki/Harry_Harlow) unethical experiments on baby monkeys, which he raised in extreme isolation. Bottom line, quoting Harlow: > > "No monkey has died during isolation. When initially removed from total > social isolation, however, they usually go into a state of emotional > shock, characterized by ... autistic self-clutching and rocking. One > of six monkeys isolated for 3 months refused to eat after release and > died 5 days later. The autopsy report attributed death to emotional > anorexia." > > > "The effects of 6 months of total social isolation were so > devastating and debilitating that we had assumed initially that 12 > months of isolation would not produce any additional decrement. This > assumption proved to be false; 12 months of isolation almost > obliterated the animals socially" > > > So... probably best to leave that bit out. Which brings me to [the Ottomans](https://en.wikipedia.org/wiki/Ottoman_Empire). Ignoring [Ibrahim the Mad](https://en.wikipedia.org/wiki/Ibrahim_of_the_Ottoman_Empire), so lovingly remembered in comments by *Royal Canadian Bandit*. The Ottoman empire was famous for its [Janissary](https://en.wikipedia.org/wiki/Janissaries) Corps. The Ottoman Sultan had a problem in terms of loyalty, he could not trust that the regional lords would send him soldiers, or that those soldiers would be loyal to him. The rather creative solution was to demand a "blood tax" from Christian communities, usually in the Balkans, of the first born son. He would be taken away, trained in Islam and war, and would become a soldier-slave loyal only to the Sultan. The Sultan's wives were also slave girls, which conveniently ensured that disputes about succession tended to be limited to the Sultan's harem... and not spill over into wars of succession, as happened all too often in feudal Europe and elsewhere. The downside was that although the Janissary were for a long time loyal, fierce, and capable civil servants... they became a bit too comfortable, and were able to extort luxury which eventually made them corrupt and decadent. Their success lasted at best a few centuries. Neither proposal would be without issue, but you could blend them into your own idea to make a new system. It wouldn't be free from fault, but it would have its own unique strengths and weaknesses which would create an interesting backdrop for whatever issues you'd like to explore. Right now your system is unworkable. You'd probably kill most of the orphans owing to your weird carer rituals, and those who survived would be profoundly emotionally and intellectually disabled. If they did become ruler, the nation would keep losing whatever precious little experience and knowledge they'd gained. Because for some completely arbitrary reason, the government, in its dedication to the pursuit of educated leaders, keeps deciding to "dispose of" the most educated and best candidate they've got every twenty years. [Answer] Like some others have said, having the king grow up in isolation will make him completely unsuitable for ruling a country. He couldn't interact with anyone but his 'mother hive' (separating him from the decision making) and probably wouldn't even want to. It might be easier to form a dolphin into a slave king than a human (since then you wouldn't assume human empathy). There might be a variation that suits your needs though: eg. a small, separate society which isn't dependent on anyone in the outside world and can autocratically rule the outer state. They wouldn't have any personal gain from their decisions either way, but when raised correctly should empathize with their country and try to help their people. [Answer] Despite the criticism of your ideas from other answers, the system that you propose is actually surprisingly similar to a real-world system that lasted for centuries: the [mamluk](https://en.wikipedia.org/wiki/Mamluk) system of the Islamic world, and most notably the [Mamluk Sultanate of Egypt](https://en.wikipedia.org/wiki/Mamluk_Sultanate_(Cairo)). The mamluks were a "warrior slave" caste that were imported and educated by various regimes across the Islamic world from Egypt to India, forming a military elite, in a system that lasted for a millenium. Unlike most elites in these places and times, the status of mamluks (typically) could not be inherited, and thus the system acted as a significantly more meritocratic means of selecting rulers than other contemporary options. Over time, the mamluks in many societies either overtly or de facto took over power in their societies, leading to various "slave dynasties," many of which lasted several centuries before their eventual decline. In short: while what you propose certainly has problems, you might find good inspiration in how to adjust it for more stability in the history of the mamluks---and also an understanding of its interesting problems in studying how mamluk dynasties decayed and fell. [Answer] It appears that what you really want is an AI, or a figurehead. Perhaps both. Since you're describing extensive effort to reduce emotional attachment, and not to give the future monarchs any interpersonal relationships, in the hope of achieving neutrality and the removal of human flaws (and human traits which aren't necessarily flaws), instead of attempting to dehumanize somebody and hope they're mentally stable AND effective at governing, I think it would be better to build an administrative AI. Perhaps model them after humans and raise them as children , but without the same human needs and tendancies? If you believe that political philosophy, economics, justice, etc, could all be taught in a neutral way, then perhaps one could form a pretty complete, "neutral" set of instructions for administrative AI to follow. While there might always be tough calls, like the trolley problem, the answers you want, and their contingencies, could be hard coded, or perhaps you would just have each AI choose their own answers based upon what they've been taught. For the ceremonial, figurehead side, it appears that usually human royalty aims for some level of detachment and equamnity, and if it can be selected for in a monestary or japanese temples, then perhaps this could be the counterbalance. Though this sounds like a non-violent jedi order, which isn't that useful unless they had veto rights over some AI decisions for instance, like the British Monarch has over parliament. Then again, why not have a ceremonial AI, with a whole bunch of appealing implicit biases, such as those towards compassion, aesthetics, and attachment? [Answer] Since everybody has already answered the > > and what problems do you foresee [this system] having? > > > part of the question, I'll answer the other one: > > How feasible do you think this system is? > > > The answer is: # It's not feasible at all, because its central goal makes no sense. The central goal of your system is to groom a single child into an apex leader who has no *"personal bias"* or *"conflict of interest"*.1 An apex leader can serve many different functions that vary from culture to culture, but we can think of a few: 1. to serve as a pretty face for diplomatic relations 2. to serve as a pretty face for local cult of personality 3. to make tough decisions that are "good for the country" 4. to solve disputes between non-apex leaders Personal bias or conflict of interest is a problem only if it negatively impacts these functions, and not only it doesn't have to, it can actually enhance them. Doing 1. with a family on the other side of the border is how alliances lasting centuries can be made. Doing 2. with personal bias for farmers might actually prevent them from rebelling. --- 1 You also say you want the apex leader to be unable to be corrupted (either by bribe or extortion), but: A) I feel your system is focused more on the other part, B) they can still be bribed (with personal freedom) and extorted (with threats like: * *"I'll kill you!"*, * *"I'll disembowel all your caretakers in front of you!"*, or * *"I'll send a squad of highly-skilled assassins at random intervals to sneak into the palace and poop into all the swimming pools just before you skinny-deep in them!"*). [Answer] The other answers are pretty well presented, but here is my take, where ### I will be making an analogy with respect to ***Game of Thrones.*** **Tommen Baratheon** and **Margaery Tyrell** are the King and the Queen. You could here argue that Margaery is in fact, the acting King. Now, let the "carers" be the **High Sparrows.** The King and the Queen let the High Sparrows care for them and soon the things went out of hand. Whatever the High Sparrows (read "carers") wanted became the law. You may have isolated The King from the corruption but what will you make of the carers? They aren't incorruptible. Corruption almost always seeps in such scenario. The isolation *dumbed* down otherwise clever Margaery to the extent that she wasn't in the know of Cersei's conspiracy to blow the Sept until the last moment, *even then*, "the carers" assumed power and didn't let her go out. **Result:** Wildfire burnt them all down with Rains of Castemere playing in the background. Tommen didn't survive either because he was into the "carers" concept as well. And he lost Maergery. Anyway, it is a bad idea(TM) unless of course your carers are extremely devoted as Tyrion Lannister is to Daenerys Targaryen as of writing this. ]

[Question] [ I'm writing a story, based vaguely off of the [Stars Without Number](http://www.drivethrurpg.com/product/86467/Stars-Without-Number-Free-Edition) system. There are lots of things bugging me, but by far the biggest issue is this: the military contractors and bounty hunters and the like are all congregating in the war-torn areas, waiting to be hired, instead of relaxing in luxury, waiting to be called. There's mostly reliable, long-distance superluminal communication, but only in the sense that you can put a message on a ship (or into the ship's computers) and have that ship carry it, mostly reliably, between systems. How can I explain why PMCs would do anything but stay at home, waiting to be hired to fight? [Answer] Not sure quite what definition you want to give of "being a mercenary", but I spent a few years as a contractor in Africa, Asia and the Middle East after leaving the Army, so I can tell you why I spent a bit of time wandering around the smellier parts of the world between contracts. **Connections** You get hired and find contracts by making sure people know you. I was in Special Forces for 6 years, and in a tiny community like that your reputation is everything. Once you get out it is the only way you get good contracts, too -- not by applying for them, but by getting cold-called by someone you know and already worked with before. But the longer you've been out of the military where assignments aren't your decision and you meet new people as a matter of course, you wind up becoming slowly isolated. Whatever sort of work you have been doing is the only way you meet people if you're only in the ugly parts of the world when you're on contract. That means you only meet people who do the same kind of work as you, and pretty soon your old contacts change careers (nobody does this forever, not unless they get paid extremely well -- but its actually feast-or-famine, and that begins to wear on you). Over time your contacts go stale, contracts become less frequent, wars end, new wars start in places you've never been, rules change, industry players change, empires come and go, languages you know become useless, etc. We watch all this firsthand, which is why we know that we can't count on being comfortable, ever, and absolutely none of us trust things like pension programs after watching entire governments implode overnight. That also means we don't have much faith in getting a next call while we're a world away sitting on our asses enjoying the good life. Yes, you do that a little, but only when you know you already have a contract lined up to go back to. **Location location location** So what does one do? Why do programmers looking for easy cash from VCs they can blindside with a storm of buzzwords migrate to San Francisco? Its one of the absolute worse places to *run* a company, but its one of the best for *starting* a company simply because the community is there. In the same way one might wonder why I would wander around a shithole like Baghdad or take a trip to Mali when job hunting? Because the community is there. Its not just bases and checkpoints and whatnot. Those of us who have to stay there a lot begin doing more pleasant things with our time. Some start up private bars, open restaurants, hire stranded immigrant workers who were screwed over by their former employers and start a service shop that handles things people like us know are needed (vehicle repair, gear cleaning, safe parcel delivery, couriers, *good* alcohol smuggling, proper medical supply import, etc.). We tend to those sidelines when we're not on contract, meet local girls ("local" as in she's there, and so are you for the moment), train with each other partly as play (its fun) and partly to keep skills alive, etc. *and keep making contacts*. It takes a little effort, but you can make life comfortable for yourself in the middle of the never-ending nightmare that is most of the world. Most of us are, if not friends, at least cut from the same cloth. We've had similar experiences. We like to swap lies (and the occasional true story) with one another over a drink. We like to roll and box with each other for fun. We have beer shoots on the weekends sometimes (loser buys for everyone). Few of us can train much back home. *People at home sincerely do not understand a huge part of our lives*. We come from the same dozen or so countries. We speak, if not the same language, the same 2 or 3 common pidgins. Its a comfortable place, even if its a rough one. And sure, maybe a few towns over people are getting their houses knocked over and roughed up by the local baddies or whatever, but *nobody* comes to mess with our little cobbled together neighborhood. So yeah, its less safe than living in, say, Austin, but its a lot safer than the general violence statistics for the region would make it appear. And the violence stats work in our favor anyway: fewer people show up who don't already know what they are doing which effects a self-selection for competence and prevents a flood of competitors from appearing out of nowhere. **We're feeding off of the chaos** Most of the world is not very well planned out. When a crisis occurs and a bigshot needs to go somewhere bad in a big hurry there simply isn't time to establish a strong guard force and mobilize it. Most countries don't even have decent diplomatic security forces (much less decent police -- or even decent people) so external contractors are a necessity. Usually an office that is already in position will get a call at the 11th hour with a desperate need for diplomatic security (or whatever else). Not ten minutes later a few of us are running up and down the street knocking on doors, calling each other "Do you have any solid guys and a few locals you can bring on a run to X in two days?" and "Hey, do you still have that bigass armored bus? How about the bricked-out Mercedes and the Rhino, are they out of the shop yet?" and so on. The next day we're all out, not officially on contract yet, but we're already rehearsing, making sure everybody knows what to do. One major advantage of working in a group like this is that you generally only need to rehearse actions-on, get guys new to a particular technique or scenario up to speed, and cover a few contingent actions. That's a *lot* different from having to rigidly train core skills because most of the trigger-pullers are privates who just left home for the first time. (The general age range of the guys I prefer to work with is 30~60 -- and don't let 60 throw you off, there is this freakish phenomenon we call "old man strength" and its totally real, and the *tactical maturity* of the older gentlemen tends to guarantee they don't have to exert themselves much in the first place, which is pure magic.) A few days later we've swapped out our patches and hats for whatever logos the prime contractor has and are standing all clean and pretty at the airfield waiting to meet the guy who is paying for the party. From the outside I suppose it looks like Xe (or Blackwater, or whatever they are now), or Triple Canopy or Aegis or whoever *appear* to be some full-time private military force you can just hire on short notice -- but that doesn't mean they have a barracks in Florida or Cape Town and are just waiting for the green light. Its *expensive* to have us around, just eating through corporate profits. They assemble their forces from people they already know *right then* and roll. (The *really* huge contracts that cover a whole warzone may wind up being slightly different in effect, because those contracts may be ongoing for 5 years at a time, but even those stories must eventually end.) The only people with some level of job security are the country/region managers and up. The polite girl who used to call me from Virginia to tell me my travel routes, for example, had *much* better job security than any contractor ever would. That's just diplomatic security. There are plenty of other contracts like training foreign militaries, providing direct QRF support, high-value recovery (sort of borderline legally), K&R response, countersurveillance, and some other stuff for example, but the way you get to know each other and find your next job tends to be the same: by being out there, being well known, being likable, making friends, working lower-paying contracts that involve a ton of people to have a chance to meet some other guys, and *remembering who the dirtbags were* so you can avoid them in the future. It sounds bad to say "we feed off the chaos", but that's true. But its also true that the chaos is never-ending, people suck, nothing is stable, and nobody gives a crap about your problems but you and maybe your family. Its not going to get any better, and it hasn't been any different throughout history -- we're just this season's leaves, soon to be swept away whether we spend them shivering in our beds trying to stay safe or out there sweating, trying to get some cash together so we can get out of the crappy places of the world and start a family somewhere less screwed up. **So in the end...** Why do gravitate to the eye of the storm? Because in a world with no job security you have to make your own luck. **What about the organizations?** The above discussion was all about the people involved, explaining some of the reasons why *I* would occasionally hang around nasty places while off contract or at least spend my off-days while on contract making sure I had a good shot at having another contract one later on (or finding a better one right away if the current one paid peanuts but was super dangerous for no reason). That's all about us guys who are on-off contract every few months (or whenever the phone rings) and have no job security. The companies that are actually getting the contract awards have slightly different, but related, reasons to always have a presence in a disturbed region. Contracting companies don't really have any job security, either. Any given conflict will eventually end, and -- contrary to the hilariously off-base conspiracy theories that PMCs "cause conflict to profit off them" -- peace could break out at any time. But this is Earth. We can rest easy in the knowledge that *war is a natural state of mankind*. The trick is, just like owning a chain of grocery stores or selling fire insurance, you have to diversify your presence and product offerings to make sure you've got market coverage if you want your company to survive beyond a sing huge conflict. (A *lot* of PMCs have come and gone just around the Iraq conflict. Others will come and go elsewhere. A few have a semi-permanent presence on the eternally screwed up continents.) When everything goes to crap and the local embassy or company office needs to source something locally, it is a *very* good thing if you've already got a point of contact in country. Nothing fancy, just renting a one-room office or keeping a local on hire to answer the phone. If operations are fairly regular, though, like when a larger trend of conflicts is ongoing, it is absolutely impossible to keep up with regulatory requirements. Your job is, after all, to wield lethal force. In reality you do this every time you move a chair, pick up a rock, throw a baseball, grab any kind of farm tool you can imagine, or get the cutting board from under the sink... but that's not how regulators see things. (And before you say "but you don't wage wars with rocks and knives and stuff" -- that is *precisely* what insurgents do.) Sourcing the best weapons money can buy in a country like the US, UK or France is not terribly difficult -- but *shipping them out sure is*. The other side is even harder: getting authorization to ship weapons into a warzone. Now that last bit is highly ironic given the typical glut of weaponry just laying around and the fact that there is usually a vibrant black market in action -- but it is absolutely *insane* the layers of paperwork, ass-kissing, bribing, cousin marriages, and personal relationships you have to maintain to ship a container of 30 rifles from Arizona to Pakistan. Given that doing things the 100% legal way involves insurmountable regulatory hurdles, and to even be allowed to do things legally one must do the illegal stuff anyway to grease the skids on the operation (the bribes, cousin jiggering and relationships part) the path of least resistance is usually to source and maintain weapons locally and then *make that legal* by way of the bribes and whatnot. The end result is that you have mountains of paperwork to do (once your cache is made legal it will have to be registered and maintained by an armorer), but its done quickly and you have access to what you need *now* (money and arms) instead of never getting the operation off the ground because someone else can beat your price and timeline by sourcing locally. Its a race to market! But maybe not the sort of race to market everyone is aware occurs. The tradeoff is money (flexible) and time (inflexible) in exchange for a much lower availability of the weapons you *want* to use. In a big theater like Iraq or Afghanistan its not so hard to get real M-4's and things, but they will often be Bushmasters instead of Colts, for example (and when the the teeth on the bolt break while you're firing... you *really* hope the rest of them hold until you can maybe find a new one and a new barrel, which is anything but certain). In a smaller theater you are rarely that lucky and will have to settle for unreliable remakes (that look good, but don't sound so good), crappy magazines (failure to feed == failure to fire), ill-maintained former stockpile gear (that works, but requires some rehabilitation work), former Soviet stock ([contrary to the popular image, the AK-47 and PKM are *not* the first choice of most discerning infantrymen...](http://zxq9.com/archives/911)), or a big fat pile of "frankenguns". And that's just guns! The situation with ammunition is absolutely laughable most of the time (protip: *practice stoppage drills*). [*Frankengun*: A firearm, usually of Soviet design, that is assembled from the not-yet-totally-broken parts of a collection of other guns that used to work. This is particularly common with PKMs, which are already bad enough when they are in factory condition compared to an M-240B\* or an MG-3\*\*.] ``` * or MAG-58, or M-60, or... ** or MG-42, or MG-11, or MG-53, or... See, guns have lineages, too! The PKM's line had a lot of inbreeding... ``` Where individuals trying to find contract work hang around to be known and put themselves in the right places at the right times, companies hoping to score prime contracts have to have an early logistical presence and maintain it in order to be confident they can service any contracts at all. **EDIT** In the spirit of this answer I'm preserving a thread that occurred in comments below that will certainly be lost to moderation eventually. tl;dr: A tech contractor who worked for a PMC some of the same places I have asked some details about where the tactical contractors hang out and we had some back and forth. Ultimately, *I want to keep in touch with the guy*. This is partly out of habit, partly to reminisce, partly because I sense a kindred spirit, and partly because who knows when it might be a good thing to know another guy who does PMC work that is into tech? <http://zxq9.com/archives/1223> *This* is what I am talking about in terms of contractors sticking together like a tangle of Christmas-light-string shaped magnetic fishhooks. [Answer] Well... I don't know if this is enough to constitute a complete and acceptable answer but here we go. You don't have to look to other realities or the future to see that happening. It's a basic issue in a capital society: If you don't make yourself known you don't exist. Your mercs are in the hot spots because there is where they are needed and have to be seen there. If their possible contractors see them there, they are prone to hire them in a tight spot or to take an off-job they don't want their soldiers losing time to. With time, mercs will make a name for themselves, get fame and more beneficial jobs for themselves. All that would not have happened if they stayed at home watching TV. As I said before: capitalist society. It's not good enough to be good at your job, you have to advertise yourself. Otherwise, others will fill that hole you left, and they will take the jobs. And this is applicable to any job :) [Answer] Historically, mercenaries also had close connections with the various noble houses which hired them (and occasionally married into the house, like Sir John Hawkwood, or perhaps simply replaced them if they were not being paid on a regular basis). Staying close to the scene of the action also provides the ability for the mercenary bands to manipulate things to their advantage. In the 1400's Italian city states often complained that the mercenaries would go to "war" without actually fighting (one battle reputedly ended with only *one* casualty (supposedly killed when he fell off his horse....) If you are a mercenary commander, you might want to compare notes with the other commanders in order to see who paid on time, who was a difficult employer and if there was an advantage to be gained by switching sides. This is more difficult if you are relaxing on a resort planet tens of light years away from the action. In story terms this also gives you the opportunity to get your characters in seedy bars or the back rooms of disreputable restaurants. Of course the people who hire mercenaries also want to keep tabs on them as well, so the agents of the noble houses also have a vested interest in having the mercenary bands close at hand. A mercenary band which is off in the distance not only is not building their reputation for fighting skills and prowess, but there may also be a suspicion in the air as to what they are *really* up to "out there". A mercenary band is already in a position where there is not a great deal of trust in them and their activities, so anything which adds to the suspicion is going to be counter-productive to their business. [Answer] I'm going to echo the actual PMC guy's great answer above, and note it even works that way in simulation. When I was running a mercenary group in EVE Online, I helped a team go from sitting in safe space and waiting for the contracts (which resulted in no contracts and a lot of boredom) to planning and executing raids on opportunistic targets AND to just showing up on the edges of war zones with a "hey, you want twenty more guys? X mil up front plus Y% of the damage we do." sign hanging out. Do that for a few weeks and suddenly you have a bankable rep and people know how to hire you, because the people who are hiring aren't hanging out in the cushy areas (those guys have their own military already), the people who need you are the ones in the teeth of it in the first place. [Answer] Because that's where the action is. Where there is war, the need for manpower increases. For this reason, they need to hire mercenaries to bolster their numbers. One more reason why they go to the hot spots is that they can pretty much guarantee employment if they are in the right place compared to those mercenaries abroad which need to be brought in, using the employers resources. We know that resources are in high demand during war time and uselessly squandering it just to hire mercenaries overseas/abroad is not using resources the way they should be. ]

[Question] [ Our forces have surrounded the modern city of Vale; a large metropolis of over 5 million citizens who all have decided to try and rebel against us and form their own country. The city has large dams and industrial cattle farms; food and water are not concerns, nor is power as the city also uses the dams for water. In order to make an example of this kind of naughty behavior our king has decided to destroy the city. Before a heavy assault besieges the city, the king has decided to first send in a squad of 50 of his highest trained soldiers to do as much chaos as possible to the city first in order to cause as much chaos as possible. He has given them a budget of 10 million dollars and 3 months, they need to cause as much chaos to the Vale rebellion as possible. What actions can these soldiers do in the 3 months to cause the most mayhem? There are a few things to consider; * Let's define Mayhem as the combined factors of damage repair cost and death tolls. * The city and its land must remain standing, but not its people. * The city is collectively rebelling and therefore there is no rebel leader. * Please refrain from answers resulting in the demolition of the city; including nukes and large scale destruction. * The citizens are rebelling **because** of the problems with this city design. [Answer] # Assassinate the Garbage Collectors Every city has workers at the bottom, doing the nasty, dirty jobs needed to keep a city livable. Chances are, dear reader, you yourself don't 'see' these people in the places you live, yourself. These people run regular routes, serve everyone, and are likely to be amongst the least protected because they hold jobs people disrespect out of proportion to their need. New York has [roughly 9,250](https://en.wikipedia.org/wiki/New_York_City_Department_of_Sanitation) sanitation workers for a population of 8.4M. We can assume, therefore, that our target city has ~5500 sanitation workers, all working at odd hours all over the city, likely without protection. Starting with the lowest-class areas, where police response will be the slowest, our commandos attack garbage routes, killing sanitation workers and disabling or destroying their equipment. Even better, they generally don't have to be there to do it. Bombs can be placed in garbage, designed to explode at certain times, when being crushed by compactors, or when they detect they're being moved a certain amount (thrown in to the back of a garbage vehicle). This serves to both damage equipment and harm or kill the sanitation workers. After the initial surge, hopefully decimating the sanitation workforce, psychological warfare can be played: garbage bags with 'I am a bomb' written on it. 'Tickers' set up inside trash cans that simply... tick. Or sometimes blow up. Or just go 'poof', scaring the bejeezus out of someone. Standard '[I am a Thirty Second Bomb](http://www.technovelgy.com/ct/content.asp?Bnum=1021)' tactics targeted at sanitation - the key is to make it unpredictable, and *sometimes* deadly. After making it clear sanitation workers are under threat, and then making it unclear if at any moment they might be killed, the sanitation mechanism will grind to a halt. To hustle it along, the commandos can start to target sanitation leadership, removing the body of knowledge on how to best manage such a large scale of sanitation need, or make a splashy assault of a waste management facility, burning it to the ground and releasing a cloud of methane gas that takes weeks to clear out of the neighborhood. Five million people produce a lot of trash. Dealing with a new reality where a non-critical critical piece of infrastructure is under attack, the rebels will have to divert significant resources to either protect this piece of infrastructure (thus not doing something else), allow the garbage to pile up (with associated health and morale concerns), or find a way to take out the commandos (assuming they're able to figure out that there are, in fact, commandos - this could be disguised). The sanitation workers would be in constant fear for their lives. It would be the sort of low-level chaos headache a rebel commander really wouldn't want to deal with. And then you give the cows Mad Cow disease, or at least suggest the cows have it - or some similar thing. Any additional shock to the public understanding of their health and safety will make them deeply question whether the rebel leadership has their best interests at heart. This works doubly well if all such leadership are actually spared any direct attack. If the lower and middle classes are the ones under the primary stress, it will fracture their support from those at the top. In a few months, King Thin-Skinned will have a pretty easy time coming in and taking out the rebels. Once conquered, he has a ready-made, easy way to secure popularity: importing a bunch of extra sanitation workers to clean up the city and make it markedly better than it was under rebel hands. Post Script: I don't know enough about main sewer lines, but again, there is a piece of critical infrastructure that is not 'critical' in the sense that it is guarded, and could be messed with. Not everywhere, but in enough places that you make things grody and unpleasant for the populace. [Answer] > > The city and its land must remain standing, but not its people. > > > Biological warfare is the most obvious answer to this question that fits that requirement. With a small band of infected individuals (or simply carriers of diseases), you could wreak havoc on the city through the spread of disease. That money could just be spent on chasing down diseases that aren't common to the people of that city. Depending on the the technology available, this could vary from genetically engineered viruses spread through public water systems to infecting their animals with human-transmissible diseases. Even in ancient times, biological warfare was in play, from [Wikipedia](https://en.wikipedia.org/wiki/History_of_biological_warfare): Poison: > > During the First Sacred War in Greece, in about 590 BC, Athens and the > Amphictionic League poisoned the water supply of the besieged town of > Kirrha (near Delphi) with the toxic plant hellebore. > > > Diseased corpses accidentally infecting people: > > During the Middle Ages, victims of the bubonic plague were used for > biological attacks, often by flinging fomites such as infected corpses > and excrement over castle walls using catapults. > > > And possibly purposely spreading diseases from other areas: > > Australian aborigines (Kooris) have always maintained that the British > deliberately spread smallpox in 1789... > > > Modern biological weapons/techniques are much, much more dangerous and could take out everyone in that city with minimal effort. [Answer] Oh @TrEs-2b.... you make this so easy: > > food and water are not concerns, nor is power > > > Then your 50 guys **make them become concerns** (\*). Modern societies are highly vulnerable because of our reliance on clean and safe water, a secure food supply, and electricity 24/7. Threaten **any** of these and you will see chaos very quickly. If this rebellious city-state has also chosen to not rely on any outside help, then this is a complete no-brainer. * Ricin and anthrax bombs at key water distribution points (there is a **reason** such points are usually kept secret) * Same on the meat farms * Attack the power grid and knock out key components that cannot be replaced on site but instead have to be delivered from outside. The irony is of course that your city becomes its own undoing by going the anti-authoritarian route. We form a **society** for the added security of helping each other with — among other things — these very basic needs. Fitting this into your premise is no problem at all. Look at any of the green ("green" as in the political color, same as blue and red) ideology movements and see what they are all about: de-centralization, self-reliance, avoid being dependent on large utilities. This is why they are all up in arms against the **big** companies; because these companies have us by our figurative balls. So your city suddenly goes ideologically green, saying "No, we dont need you! We are self-sustaining. We can do this on our own". But things like water, food and power, that is not at all easy to do on your own. Especially not when someone throws a monkey-wrench in the machinery... I highly recommend you watch the end of the epic movie [Lawrence of Arabia](http://www.imdb.com/title/tt0056172/combined) to see this entire scenario played out, in the city of Damascus. Watch how the British just smirk, lean back and wait for the inevitable to happen. Then they just walk in and take over. (\*) First rule of hackers, saboteurs and similar: as soon as anyone says "Don't do this, or it will be a problem", or "That thing is never any problem"... guess **once** where these guys will be focusing their efforts. [Answer] Since widespread destruction is not an option, I would engage in small-scale destruction. Attack infrastructure that can be replaced without rebuilding the whole city. **Blow up the sewage treatment plants.** Maybe target specific machinery that cannot be produced in the city, but can be replaced once the city is reclaimed. Once the sewers back up: toilets overflow with feces, showers fill up with water, kitchens are unsanitary messes. People will be in close proximity to nastiness including feces: remember, this is a city. Rather than walking outside of their rural or suburban home, we have hundreds of people living in close proximity in apartment highrises. Disease will spread. People will starve due to any room remotely resembling a kitchen being a disgusting, filthy mess. Families don't really have yards or personal spaces other than apartments where they can live in extenuating circumstances. Apartment is full of raw sewage: where do you go? The roof? The streets? Either option is demoralizing. In general, "living indoors" will become impossible. People will be weak, sick, and utterly demoralized. By the time your soldiers move in to reclaim the city, killing its residents will be like shooting fish in a barrel. Then the cleanup begins... [Answer] **This a really FUN question. I love it!** There's plenty that can be done. All people need food, clothing, and shelter. All attacks against the Vale citizens should keep that fundamental fact in mind. Here are some very important examples: 1) Transportation choke points and hubs should be destroyed. Supplying food, clothing, and shelter is impossible without transportation. All important transportation arteries (bridges) and hubs should be destroyed simultaneously. It would take Valeans a VERY long time to repair this damage. This will go a long way in making life miserable for the Valeans. 2) Critical water supply lines should be poisoned with a chemical that isn't detectable by taste. Many people will die before the cause is determined. 3) The most critical avenues of communication must be severed to allow steps #1 and #2 to take place. An **electromagnetic pulse weapon** would be ideal for this. A misinformation campaign should be waged simultaneously to maximize confusion by using friendly military communication technology. 4) Any weapons stores should be destroyed and any police forces that may exist should be neutralized. 5) A **neutron bomb** would be ideal for destroying people and leaving all infrastructure intact. That's why neutron bombs were made. They tear DNA apart. [Answer] Go after the road networks first, bridges are ideal bottlenecks. * Cripple the ability for the rebels to logistically move around the city. They have food supplies, but the ability to move those food supplies and distribute them around the city are easy targets (and also easier to rebuild after the city is taken). Roads to and from the cattle factories (trains as well) mean the city can't access it's own food supply. * removes their ability to move their own tactical items around the city. It's far harder to defend a city when you can't move equipment around as you need * Isolate the populations. Communities without roads result in isolated and un-supplied populations (what good is a grocery market without a road to get food there). This is a heavy pressure on the population as they'll have to resort to other means to get the items they need and even travel to their places of work. Public transit (light rail?) also make ideal targets as this restricts peoples movement around their own city. Second is to further demoralize the population...terror tactics work. * Locate large gathering area's in the city, busy intersections or public meeting area's work best, and create make shift bombs. Death tolls are kinda meaningless here, as long as there are some death, people are going to be scared of entering these large public areas. This also limits their ability to gather and plan. * Banks and financial targets. Cripple them economically and make people afraid to access their financials. * Data centers. Might take a little more research, but most IT networks follow a hub and spoke setup. If you can locate the key information hubs in this city, you can cripple their ability to communicate. Add in that they are already isolated from public area's, road networks, and now communications, you will inhibit their ability to organize. (as a side note, cell towers could work as targets, as well as satellite arrays) * aid centers. This one is a bit more mean, but as food supplies become harder to access, people will have to resort to aid. Aid is usually distributed from a central source...if people are too afraid to enter an area where aid is given, how exactly do they get their food? * Power distribution hubs. Same idea as the networks...if you can locate the main power substations that route the power, hitting a few key facilities could drop their entire power grid. Bonus points if your elite soldiers can find a way to spike electricity on the grid...try to fry all electronics attached to the power grid before dropping it. [Answer] If you want to cripple a large population center, you target the infrastructure, not the people. A lot of your money is going to go to explosives and highly energetic combustibles (and hey, those are pretty cheap...so your money will go a long way). Your first goal is the dams...blow them up. This deprives the city of water and power and also wipes out anything downstream of the dam in a flood. Without running water and power, industrial-scale cattle farms lose the ability to keep up their industrial pace, thus crippling their food output...however, they may have generators and other back-ups to keep them running for a bit longer, so your next goal is to set as many of these industrial farms on fire as you can. Use plenty of accelerants, make the fires spread like mad. Target the stables and slaughterhouses. They have now lost the ability to replenish their food and water supplies on a scale able to keep up with 5 million citizens. This will also result in any foods that are not shelf-stable going bad (anything frozen or refrigerated) within a few days. You are going to want to make these strikes as quickly as possible so the rebels don't have time to reinforce their defenses enough to stop you. Now you just sit back and strike at targets of opportunity (anywhere that looks too stable or has a large stock of supplies...again, fire and explosives are your go-to options) while the city rips itself apart. A Metropolis cannot survive without a steady input of mass amounts of food and water, and in a crisis where food and water are limited, people tend to start fighting over it (Even the lead-up to a hurricane sees fistfights in supermarkets as people are trying to stock up on supplies). Add to this the fact that the rebels will try to prioritize getting food and water for their soldiers (you can't expect an army to succeed on the field if they aren't eating/drinking), and now you have the citizens of the metropolis fighting the rebels for food, making things even more chaotic. Ultimately, it's classic siege doctrine. Block access to the outside world, destroy their food and water, let time and human nature do the rest. Sure, they were unhappy when they were part of the kingdom, but at least they had food. [Answer] Well, for the cows you can bring parasites and/or rats to work on their fodder. You probably don't want to mess with disease, but a nice anthrax would ruin may people's days. The water situation is pretty easy to break. If they use the river for trade, then there are probably locks to allow movement past the dams. messing with the mechanisms for the locks, or causing damage to the dam structure itself all work, including overflow runoff works and things like that. If you really want a spectacle, blow a dam, a smallish hole is typically enough, particularly if the overflows are jammed shut. Additionally, if you have dams that's a perfect place for hydroelectric power generation, that's always fun to muck up. Either destruction for blackouts, or nice mayhem with unpredictable faults (sabotage) getting their techs up in the middle of the night, maybe capturing them, or worse. [Answer] Don't use the soldiers at all, at least not overtly. Instead use that money to fund the seedier elements of the city, or would-be martyrs that have it in for this infidel-infested city. Have them target infrastructure and conduct simple mass-shootings or terror attacks, absolutely wrecking the morale of the city. You could use your own covert units, but it's best to just let your expendables handle everything. After a few months, you could march right in and be hailed as saviors and liberators. [Answer] Since you reject nukes this must be a modern technology or higher city. Assuming it's not too far above current technology you can cause the city to become basically uninhabitable for **far** less than your budget. A few saboteurs slip in, the target is their powerplant (or powerplants). Thermite charges on the transformers. Fire them all at once so they're not alerted to the threat until it's too late. They now have nowhere near enough power to operate their city. No refrigeration--they're back to the old days where meat is consumed within hours of slaughter. (Good luck distributing it that fast.) All electric cooking devices don't work although there might be some gas powered ones. The sewer is gravity fed--but soon the treatment plant becomes a threat to health. Gas might stay up for a while although the storage facilities are almost certainly vulnerable to RPG. [Answer] Offer 10 millions to the only person that can escape alive the city. You do a **fake ultimatum** (people in city does not know it is a fake ultimatum). > > We will nuke the city within 1 month, we will take out of the city by helicopter only 1 person from the highest building within 29 days, we will give 10 millions to that person, and nuke the rest of the city. At day 30 we will launch the nuke. > > > The 50 trained persons will just hide there and there to watch the situation evolve, staying low-profile and eventually sniping during manifestations to avoid formation of big groups of people. Also **cutting out all internet/television/telephone is a must**, without commuincations people can't organize, there will always be some smart person that will argue that the ultimatum is a fake. Stopping things like facebook, mail is the only way to effectively stops a rebellion and to give the information you want. If people can't feel they can have success and the only television transmission is against the rebellion then you cannot have people act as a real nation, because everyone would be on his own, so there will not be any negotiation at all. Just pure media-terrorism. By saying that those forces want to bring havoc you indirectly already stated that your government is almost a dictature otherwise they would not take any military/police action. [Answer] We would sometimes play a variant of this game, and there are a lot of answers. While writing about one method is boring, writing about the conflagration from many plots at once could be exciting. You should look at the novel [Wasp](https://en.wikipedia.org/wiki/Wasp_(novel)) as ways a single infiltrator can disrupt a planet. Seriously, the usual defense is to keep down unrest. While it only takes one person to shoot transformers and then shoot the first team to respond, and this does make every utility truck roll require SWAT, this only worked in a novel where people didn't like the utilities and police. Otherwise, citizens would rise up in numbers to hunt down the threats. In real life, attacks are not well organized. For example, the usual suicide bomber is some twit with an engineering degree, no job, and recently dumped by his girlfriend. Instead of engineering an automated death clank, these twits kill themselves in some messy way to commit suicide with extra bloodshed. A major part of your story would need to be on the unusual motivation needed to make a rational attack. The motivation would need to survive the human responses to maiming innocent children. [Answer] # Guerrilla PR Campaign 50 well-armed and well-funded troops wouldn’t stand a chance in a city of 5 million. They simply couldn’t do enough to destroy the population or cause enough mayhem without taking out the City’s Dam (which presumable the King would frown upon). A city of that size would have a police force, civilian guard, angry locals, etc, etc, that wouldn’t be too happy about these guys running amok in the city and would do their best to stop them. In fact this could actual help galvanise the city against the King. Their best chance is to take the $10 million and hire a good public relations firm to help them get their message out that the King is angry and plans to lay siege to the city in three months. They could put out filers, run ads, and maybe write a catchy theme tune for the upcoming siege… ``` "...Get out its not too late, Before you meet your fate, You dirty stinking ingrates, Escape, escape, escape…” ``` Each person they can convince to leave the city would be a draw for two more. With a little luck the city would be depopulated and still standing when the King and his army arrives. [Answer] If the city is as reliant on computer control as our western world is, the answer is clear: Attack their computer systems. Take your budget to develop viruses (think Stuxnet) and train your elite soldiers in hacking. Then infect their control systems. The infection would at first remain silent, so you have time to infect all the important parts. The attacks would in particular do the following: * Destroy the financial infrastructure. Most of the money in modern times is stored on hard disks. Make sure backups didn't work correctly for long enough that any good one has been overwritten. Then erase all hard disks, and kill the software. * If the traffic lights are centrally controlled, then switch them all to green at the same time (causing massive accidents everywhere in the town). Destroy the normal routines controlling the traffic lights, so normal function cannot be easily recovered. * Similarly, disrupt public transport (like railway systems). * Disrupt communication, by making all internet routers go down, and also disrupt the phone system. * Disrupt water supply. * After the chaos begins to grow, and before people had a chance to get things operational again, kill the power grid. Ideally not by simply shutting it down, but by overloading the transformers so they need to be replaced. At this moment, normal life in the city will essentially come to a halt. * At this time the chaos will be large enough that your elite soldiers will have no trouble to physically get to secure places and do more traditional sabotage, if this should still seem necessary. As a bonus, since they are cyber-attacks, all those points except for the last one can be done remotely. No need to risk anyone to be caught in the city before it is effectively unoperational. ]

[Question] [ My world has a large cash loan company(we'll call it quick cash) which has a time travel device at each of its branches. when somebody comes in saying they need a loan, the employee grabs the cash they prepared yesterday, and then hop into the time machine. They travel to yesterday, tell past them the amount of money to prepare for a customer tomorrow, then drive over and deliver the cash. Simple? No. Then this is where it gets confusing. If the person never comes in because they got the cash they needed, how does quick cash make them pay back the money? If they get the cash before they ever signed anything or asked for it, then they could argue that since they never signed anything in that timeline that they don't have to pay quick cash, and if they do end up needing cash they could argue that they would go to a different quick cash type store. How to make sure quick cash gets their money back after giving someone money yesterday when they will need it today but haven't signed any legal things in the timeline they get the money yesterday? [Answer] Your primary concern is easily resolved. **Signature on delivery**. All the paperwork is signed in the past when the money is received, you just need to remember to go into the office the following day to request it so you don't cause a paradox. The bigger legal concern is that for the duration between delivery and despatch, the cash you're holding could be considered counterfeit as it's a duplication of currency already in circulation. [Answer] ### They make you use the time machine first. 1. Walk in. "I needed money yesterday" 2. "Excellent sir - come see our money lender yesterday." 3. Walk through a portal that's permanently open to yesterday. 4. "Welcome to yesterday! Sign here!" 5. Money appears in your account, in the same timeline that you signed the contract. They notify past you of the money arriving. 6. The only way out of the office is through the time portal back to the future. 7. You come out, and the loan you just signed is one day old. * No duplicate you existing, no paradox. * You signed the loan papers at the time you got the money. Of course, if I had a time machine to yesterday, loan-sharking is not what I'd do. Stock market and lottery numbers. [Answer] First of all, most customers won't need their money *yesterday*. You may be in a sore need of money, right. But you can usually forecast your need at least a few days in advance before you are broken. So why does your QuickCash company offer this service if few people would actually use it? Marketing. Offering to lend you cash *even before you know you need it* is a advertising line. This actually drives more people to your services. They could borrow \$10000 from StingyLender a bit cheaper, or from QuickCash. However, QuickCash will lend you \$15000 *today* if *tomorrow* you discover that you actually needed a bit more. This is mind-blowing, but customers like to have that extra safety, and do pay for it (or actually, they agree to pay in the future for that assurance that they would be given such money in the past). There are even insurances whose policies cover up to \$AMOUNT of QuickCash lending in the past. So, how does this work? The new customer comes into QuickCash, meets with one of their representatives and explains how much they need, why they need it in the past, the circumstances that caused that sudden need, why they will be able to repay, etc. When both parties agree on the terms, the customer signs a notice template that will be sent to the customer past self. This form is sent back in time (ads make it look like there are time-travel machines on every office, and they sent people back. Actually it's more like a Fax machine, and only a few sites do support it, other offices route their past-messages through those which do. Million times cheaper this way). An office staff from the past picks the documentation from the future office and visits the customer in the past timeline. Your future self has asked us to lend you $10000, since you will need them in the next 24 hours. The past of the customer may read the agreement, and QuickCash reputation precedes them anyway. Two options here: * Customer in the past agrees that he will need it, thanks QuickCash and signs the contract in the past. No big difference here. * Customer does not believe he might need such amount tomorrow, he has enough money, a nice home and a lot of fields, this must surely be a trick. Then the QuickHash representative goes all in. He offers a (slightly more expensive) lending arrangement. QuickCash is a really nice company, and would not like to see a future customer struggle for a money he didn't want to loan in the past. So they will lend him those \$10000 anyway for 24 hours. If the customer returns them the next day, there will be no penalty and, moreover, if he doesn't borrow anything from anyone in the next 30 days (thus showing the loan was clearly not needed at all), QuickCash will let the customer keep half the amount it had lent him needlessly. So in this case, that would be \$5000 for free if the past customer was right. Easy money. The trick is of course in that the staff at the future made sure beforehand that customer will indeed need that much money and would not be able not to take a loan. When the customer faces \$tragedy next day, he happens to have enough funds, thanks to QuickCash and the contract they signed the day before (thinking he would never need it). [Answer] It's not the legalities that are complicated here, it's the logic. If you have a time machine, why not just send the customer ahead to the point at which the loan would be due? If his future self has the money, and is willing to give it to the present self, the money is all set, even if the future self has to give it to the company who will give the past self equivalent money from the past day; if the future self doesn't have the money or isn't willing to give it up, why would you lend him anything? (Then send the present self into the past to pay off whatever needs to be paid off yesterday.) A loan is a clumsy and ineffective way to make use of future money, what with credit checks, signatures, the risk of death, and all that. Selling trips to the future is an adroit and effective way. [Answer] They don't pay *you*, they pay the person you owe money *to*. 1. You try to pay your rent for the month, you don't have enough money. 2. Your Landlord gets paid, *but you don't know that yet*. 3. You are informed by your Bank that you did not have sufficient funds for the transaction. 4. You go to QuickCash (*"Funds delivered at 88mph"*), and take out a loan for the missing amount. 5. QuickCash go back in time with the signed loan agreement, and give the Bank the money. This is paid to your Landlord in Step 2. 6. The Bank send you a notification of insufficient funds, which you receive in Step 3. If, after receiving a notification of insufficient funds from your Bank, you *don't* visit QuickCash — or a rival company, such as GalliPay (*"Home of the TimeLoans"*) — then you will instead later receive a notice of non-payment (or even eviction) from your Landlord. Unfortunately, by this point the loan companies are unable to help you. So, the benefit of visiting QuickCash (other achronal loan companies are available) is that you do not have any late-payment issues with your Landlord. Of course, this is all basically just a fancy Overdraft. [Answer] As with any financial service, you have to sign up for it and have credit checks run and so on and so forth. This way, there are no surprises when the Qwi€ash truck shows up at your location. You may not yet know why you need the money, but the packet will include the standard reminders about the nature of transtemporal financial services (e.g., Qwi€ash shall not be held liable by the present-customer for the past-customer's mismanagement of the money). Furthermore, the cash packet will likely include a note from present-self to past-self regarding what the money is for. I'd also suspect that such an operation will have all kinds of legal boilerplate regarding use and misuse of the service. One key point that comes to mind immediately is that a customer can not send money into the past beyond the point in time when Qwi€ash was constituted. Very likely, loaned moneys can't be used to play the stock market or other forms of gambling. There may also be loan amount limitations. As for being paid back, the loan shall have been on the books since the date it was delivered to the past-customer. Since the cash packet has to be signed for in the past, that will serve as a countersignature to the loan application made in the present. [Answer] You don't need the money yesterday, you need it right now ! When your landlord ask for the rent, when your loan shark comes knocking on the door... you press a button on your app which registers the need. Regularly in the future, they check your bank account to see if you have enough money. When they see that you have enough to reimburse them, they collect the money and send a message back into the past BEFORE you press the button. Procedures are launched, money is moved and in the same instant that you pressed the button, money is credited to your bank account or someone with a load of cash enters through the window (someone is already at the door, remember). If you don't get the money when you press the button, it means that you never could reimburse the loan in the future. This way, each loan is a self validating temporal loop, the bank is making money with no risk at all and there is no paradox nor alternate universe. The only things unknown are : * Would you have been able to pay the loan if you didn't have the loan ? * Isn't the reason for which you couldn't pay the loan the fact that you didn't get the loan ? * What makes some loop loan-possible and some not ? Nobody knows, but that's just how time works. [Answer] This is too easy. First, instead of bringing money back in time (basically printing free money, as there will be (People taking out loan \* loan amount) extra money in circulation every day), and, instead of sending people back in time (unavoidable paradox, there will always be two of the same person), just send the loan paperwork through the portal, pick it up yesterday and transfer the money (which you already did, yesterday), and if the person doesn't pay back the money (assuming on the day after the loan is requested, and two days after the money was given), just simply send a note back to yourself to deny that persons loan. You'll have already gotten the note, already denied the person, and have not lost any money since you read the note and denied them the loan. [Answer] Okay, I thought about it again, and I realized that neither the money, nor the person, needs to go back in time. The trick is that the only thing that needs to go back in time, is the **information**. No 'time travel' necessary. The 'time machine' in the QuickerThanQuickCash store branches is just a computer linked to computers in the past. And in fact, since the computer data connections and technology would all be made originating in the present and extending into the future, for future use, no changes would ever have to be made 'in the past'. It would all be 'from this day forward'. That is, the future 'you' deposits money through automatic banking into your account today. It is all done by computer. Only the information about the deposit has to be made 'retroactively'. If there are enough QuickerThanQuickCash store outlets, then everyone would know about it. They would not be suprised that money showed up in their account, as everyone would be doing it. In fact, you might **expect** to get cash from your future 'you', just like today you might get cash form a relative, depositied into your account, without expecting it. The money would just show up. But just because 'you' got the **cash** today, 'you' would still have to go into the QuickerThanQuickCash store tomorrow to arrange the loan. Failure to do so means that the cash does not show up in your account today. It's all about information and data traveling through time, not physical objects. Even though 'you' got the money today, the loan is still made tomorrow, and the documents are signed tomorrow. 'You' are still legally accountable for the documents you sign tomorrow, in all of the days after tomorrow. There is always only one 'you' at any one time, and there is always only one timeline. The only real difference between on-line banking under the reality of today and this scenario, is that 'you' would just assume the money that showed up in your account today was a result of 'you' taking out a loan tomorrow, instead of some mysterious benefactor puting the money into your accounnt today. In fact, the deposit could have a notation that indicates it was a deposit from the future. Interest would be paid from the date of deposit, of course, by contract, but 'you' would be well aware of this when 'you' took out the loan, 'you' agreed to it at the time the contract was made. It would be entirely legal and enforceable from tomorrow on through eternity. It would not, of course, be enforceable 'today', because the contract was not signed 'today', but this is of no consequence to QuickerThanQuickCash store in the future. They really do not care about today, that is in the past. Really, it would be like sending a money transfer to another person today, except that it would arrive yesterday, and the money would be available yesterday, not today. Since it is not really physical money, but a number on a spreadsheet, there would not be any timeline paradox. When 'you' take out the loan tomorrow, 'you' already know it has already shown up in 'your' account today, 'you' just did not know today that 'you' took out the loan tomorrow, until it shows up. Nothing really changes in time. Nothing changes in the past, because of a change made today, so nothing changes today because of a change made by someone in the future going back into the past. Just an accounting procedure made retroactively. It does play havoc with our current notions of 'causality', and about things in the future causing things to happen today, but this is sci fi, after all. Granger causality is in some ways just as weird. But still, even though it happened today because of something in the future, it still happened only in our timeline, and our timeline only occured once. What happens, happens, irregardless of when it is caused. I am not really sure what the economy would look like, when money could routinely be depositied into an account in the past, but it would be interesting. I suspect, at the least, that convention would demand no money would ever be transferrred back into the past beyond the time that the technology was first made available, because that would really botch up the bookkeeping. In fact, since the technology did not exist further back in time than when it was developed, I see no way money could be transferred back before the technology was implemented. But it would be fun to hope, today, that someone from the future just might send you money today. [Answer] **The customer pays you back up front** It's not clear when the loan is due for repayment, but the simplest solution seems to be that the customer walks in to QuickCash, asks for a loan yesterday, and as part of the process immediately repays you the loan and interest. You then travel back in time and give the customer the loan. This still works if the loan is needed for a longer period than a day. Customer walks in today and tells you he needs money yesterday. Customer then goes about their business. At some point in their future, they walk back into QuickCash and pay back the loan. You (or a colleague) then sends confirmation back to "now" you that the loan has been repaid, and only after receiving that do you go back to yesterday and extend the loan. The customer doesn't even really need to come in and ask for the loan, since you'll know from the repayment confirmation that you need to go back and give it out. That way you're always guaranteed to be repaid, and as a bonus you don't even need any cash reserves in the first place (if the customer has to pay it today - if they're paying it back on the future you'll still need reserves to cover the difference, unless you can just send the cash back to today from the future when you get the repayment). It also resolves some potential paradoxes and timeline issues - you will give the customers the cash, because you already have. And this all happens in one timeline, since the customer who pays you back has to be the one who you gave/give/willan on-give the cash to. The only outstanding question is the old one of where does the cash come from, since it only exists in that closed loop, that's the bit you need to handwave. [Answer] # Signature on delivery. All the paperwork is signed in the past when the money is received. When your past self signs, that's all the authorization PREDAY LOANS needs. They'll use that signature to take care of everything, and if they require collateral, they pick it up when the "past self" signs. # Paradox avoidance If the customer's past self refuses to sign or fork over said collateral, the company rep simply leaves. It's true said loan office would have never made the trip if the customer's future self hadn't asked. If the time travel changes the customer's behavior such that they never contact PREDAY LOANS, the company will ensure no paradox happens of their own accord. At the appointed time, if the would-be customer shows up, trying (in vain) to send themselves money they already refused to accept, that would be ... pretty weird, but not problematic in the paradox sense. If the customer no-shows, the company sends itself a paradox-avoidance order at the same time they would have sent it at the customer's behest. In this case the rep will still have the details of the "original" offer, and probably won't even know it was refused (to avoid weird meta-influences). In this way, smartass pranksters cannot cause a grandfather paradox by saying to themselves "Okay! If P.L. doesn't call me today, I go into their offices tomorrow and send myself a hundred bucks. And if they do, I'll refuse to sign and then make sure I *don't* go into their offices tomorrow! I ain't afraid of no time cops!" You might think this would result in very strange orders sometimes just ... happening, for seemingly no reason. That's absolutely true. Breaking causality (the idea that cause always predates effect) has very strange consequences. Events can happen because they cause themselves to happen, and for no other apparent reason. # Other paradox issues This company can really *only* give loans. It cannot be in the business of sending messages back in time. That's a big no-no, it's far too likely to cause paradox problems. People might try to use P.L. as a signalling service, by sending coded messages in the timing and amounts 'borrowed'. Suppose my friend wants to give me an illegal insider trading tip. He contacts me, then I go borrow a hundred bucks via P.L. As soon as I'm done signing the company's paperwork, that means now is the time to turn around and sell my stock in XYZ corporation, making a killing. This poses a much bigger risk of causing a paradox (because the effect precedes the cause in a way that impacts a lot of other people). From a legal perspective, not only will P.L. ban this in their terms of service, it will probably literally be a criminal act to use their services to send messages (by morse code or any other kind of steganography where you hide information in the fact that a request was sent and in its particulars). (In this specific example, insider trading is already illegal, and you better believe the SEC will know this trick - they'll heavily scrutinize any trade made by you or an associate during the interval between when the request was received and is later sent.) # Biggest paradox risk is P.L. going under The company going under obviously poses a fairly large risk of causing a paradox. A bigger paradox concern is people who (for example) on Tuesday send a loan officer to themselves on Monday ... so they can mug her. (Or something nefarious). Shenanigans similar to how the company avoids the "hiring P.L. changes the customer's behavior so they never hire P.L." paradox can avoid such problems. Besides which, making enemies of folks that can arrange for you to have never even existed in the first place is not a smart move. # Avoiding cash duplication An interesting wrinkle is that if P.L. sends actual cash back in time, it might be technically counterfeit. There's a brief window of time during which the customer has bills which are an exact duplicate of other bills in circulation. Avoiding this is easy. The company doesn't send hard cash back in time; it sends itself instructions, according to which the (past) loan officer gets the client their money from a bank. [Answer] Existing answers are too overly-focused on the transactional side of the business. I help companies adopt new technologies, so let me tell you how I would sell this one and how it can be implemented profitably and with no paradoxes: **Sales & Lead Generation** All successful businesses are great at finding new customers. Pre-day lending is no exception. So, a customer walks in to Quick Cash saying they needed money yesterday. Customer fills out an application which includes detailed personal information, justification for the loan, phone number & best time to call yesterday, etc. There is no fee for applying (you'll see why, below). Quick Cash runs a background check, income verification, etc, then retro-emails the information to the office yesterday. What does the office yesterday do? *They forward the email to the sales team* It is the salesperson's job now to reach out to the Customer Yesterday and explain their loan they haven't applied for yet has been pre-approved (should we say, post-approved?), and all they have to do is come sign the paperwork and get the cash. The Customer Yesterday may accept or decline. **What happens to the Customer Today in the original timeline?** The original timeline is always rewritten. If the Customer Yesterday **declines** the loan, the Customer Today has no reason to apply for a loan he JUST declined, and is anyway blacklisted from applying for a loan for another 24 hours. It's just a record in the computer, from the past. No paradox. If the Customer Yesterday **accepts** the loan, the original timeline is rewritten and the only evidence of an alternate timeline that remains is a record in the computer dated yesterday that says, *call this guy at 3pm and offer him a loan*. Also, no paradox, it's an ordinary loan without any legal complications, and Quick Cash makes a profit from the loan fees. **Why don't they charge an application fee?** If you use this model of time-travel, where paradoxes are avoided by rewriting the timeline, there is no stable timeline in which Quick Cash gets to keep the application fee from Today. The fee has to be charged or agreed to Yesterday when the cash is picked up. This insight is key to profitability leveraging this technology. [Answer] There is no way to say for sure since different countries have different laws, and there is no way of predicting for sure how courts and future legislators will rule, but I can think of a few possible issues: **If you mean literally "yesterday"** Offering yourself a loan yesterday using time travel does not make a lot of sense. Financial institutions already offer grace periods for things; so, for financial adjustments over such short periods of time, we already have systems for doing that without actual time travel. So, for the remainder of this answer, I will assume you mean some time far enough in the past where time-travel actually becomes meaningfully necessary. **It could be challenged as Ex Post Facto in some jurisdictions** <https://en.wikipedia.org/wiki/Ex_post_facto_law> Most places today have laws that prevent retroactive legislation; however, only some nations extend that law to civil situations such as contracts, debts, civil suits, etc. Places that have more absolute interpretations of Ex Post Facto law may prohibit this practice because you are assigning a debt to someone retroactively. **Most places require loan agreements to be signed and dated as of the date of commencement** Because the date of agreement is a material component of loan agreements, many jurisdictions can nullify a loan agreement if the date does not agree with the context of the loan. So a loan that is signed and dated in 2105 but begins collecting interest in 2100 it would be indistinguishable from lender fraud. Moreover, if you sign it in 2105, then no notary in 2100 will not have a record to confirm against; so, there is no proof of a legally binding agreement in 2100. Then there is the time paradox issue. If I receive money in 2100 and it alters the course of my life, then there is no guarantee that I will walk back into the bank in 2105 to sign the paperwork which (for some versions of time travel) would leave the lender without any proof that I ever agreed to a loan. Lastly, if you go back in time to 2100 to sign and date it before a 2100 notary, then there are two distinct versions of you in the same timeline meaning that you would most likely be treated as a separate legal entity from your past-self (like a twin or a clone, you are no longer materially the same person). **It could be challenged as insider trading/civil damages** Older you may not be able to obligate a younger you to a debt; so, the bank instead just extends a line of credit to the younger you which he may or may not choose to accept. Let's say in 2100 you had a really low credit score. You wanted to buy a house but could not; so, you rented instead. But, then you got your life together and started saving a lot of money/paying off debts, etc. Then in 2105 your debts are all paid off, and your credit score looks great. You could then go to the bank and say, "Hey, I want to apply for a house loan in 2100." They could then send your current financial information back to 2100 and use that to prequalify the younger version of you for a loan. So, the 2100 version of you is looking at a pile of bills, losing sleep at night, etc. when you get a call from the bank saying that you've been. PrePost-Approved for a home loan. It is then up to the younger version of you to decide if he wants to sign up for the loan or not. This may sound like a nobody gets hurt scenario, but it's not. The owner of the apartment you were going to live in for the next 5 years just lost out on rent money because the bank engaged in a sort of insider trading. Now there is the risk that the Landlord could sue the bank for damages. [Answer] Let me see if I have this right. A man with a broken arm and leg goes into a QuickerThanQuickCash store to borrow the money he needed yesterday, so he could pay off the loan shark, so he does not end up with a broken arm and leg. So he completes the loan, goes back in time to get his money, and indeed pays off the loan shark. The loan shark is happy, and does not break his arms and legs. The man from yesterday is really, really glad to see himself from the future come in with the money to pay off the loan shark. But he has not yet borrowed the money from QuickerThanQuickCash store to pay off the loan shark, so he still has to go into the store the next day to borrow the money. Otherwise, he can not pay off the loan shark, and he has his arms and legs broken. So he goes into the QuickerThanQuickCash store the next day, without a broken leg or arm. He gets the loan anyway, even though he does not need it today, but definitely needed it yesterday, and goes back in time to collect the money to pay off the loan shark. Since the loan shark has not been paid back yet, the loan shark is happy to get the money, and does not break the man's arms and legs. But he still needs to borrow the money the next day so he can pick it up yesterday to pay off the loan shark so he does not get his arms and legs broken. So the next day he goes into the QuickerThanQuickCash store to borrow the money. Seems to me that he is now in an infinite loop. But at least his arms and legs are not broken. Unless he fails to go into the QuickerThanQuickCash store the next day to borrow the money yesterday so he can pay off the loan shark. If he fails to go into the QuickerThanQuickCash store, he does not go back to pay off the loan shark, and he gets his arms and legs broken. When that happens, the next day he definitely goes into the QuickerThanQuickCash store to borrow the money yesterday to pay the loan shark so he does not get his legs and arms broken. Except, how does the QuickerThanQuickCash store get their money back, if he is caught in this infinite loop? And why, if he got past this loop, would he not just go into the QuickerThanQuickCash store the NEXT day, to borrow the money yesterday (today) to pay off the loan at the QuickerThanQuickCash store, as soon as he took out the initial loan? It would seem to me that, when he went into the QuickerThanQuickCash store, he would be in danger of meeting himself from tomorrow, comng back to collect the cash to pay off the loan he had not yet taken out, but will take out yesterday? It would seem to me, that there would be no room in the QuickerThanQuickCash store, because it would be filled with an infinite number of the same people coming in from the future to borrow money today to pay off the money they just borrowed today to collect yesterday. Steven Hawking once famously said that he absolutely knew there would never be time travel, because if there was, our world would be saturated with tourists from the future. Time travel works when you are the only one. And what is the profit for the QuickerThanQuickCash store, in that? [Answer] When you travel back through time and alter the past (as in giving yourself a loan yesterday), you cause a divergence in the timeline. This would either cause a paradox, blowing you (everything?) out of existence, or it would cause a split in the timeline (multiple realities). Assuming there is no paradox ending reality, then there are two possibilities - You travel back to the same reality you came from (where it would appear as though nothing had changed - your loan to yourself never occurred), or you would travel back to the alternate reality, where your past self received the loan, however this has diverged from reality and you are now a separate being that has essentially popped into existence out of nothing (your alternate self still exists and is living their life). In the first instance, whereupon on your return your past self did not receive the loan, you have not benefited from the loan, however you did still take it out and are obliged to repay it. In the second instance, whereupon on your return your past self did receive the loan, but you are now an extra entity that has popped into reality out of nothing, the loan was never given and there is no obligation to repay it. However in this reality, the money from the loan is essentially counterfeit (the loan was never given and the money used for the loan now exists in multiple locations, in the same way you do) [Answer] Simple: **Reality cannot contradict itself.** Receiving the money is real. Sending the money is also real. Receiving the money happens exactly when the sending also happens. And there are only two valid solutions: Either the lender receives the cash yesterday and returns today to send it, or they didn't receive the cash in the first place. Under the "reality cannot contradict itself" regime, pretty much all the time travel paradoxes disappear. At the same time, it still allows for interesting plots to happen, where the future influences the past and current. It only restricts the things that have happened to be influenced by the things that are actually going to happen. [Answer] 1. Customers comes to the branch and asks for a loan. 2. Loan is authorized, customer signs a 2-steps contract confirming he agrees to receive the money yesterday, and leaves a copy of an ID as a reference. 3. Employee grabs the money, the contract, and the copy of the ID, travels back in time, and delivers the money, asking the customer to sign again the 2-step contract, confirming he actually asked/will ask for the money and that he is indeed receiving it on time. 4. Profit. ]

[Question] [ The apocalypse has come - nuclear war+asteroid hitting+alien invasion+Skynet+vampires. Doesn't matter which, the world government/s knew this was coming (lets say, a year in advance) and they have a plan! They'll get as many "chosen ones" (scientists, craftsmen, leaders, soldiers etc etc) off to the Mars colony, where life can begin anew. The chosen can bring their close family along. To do this, the powers that be contact the chosen ones 24 hours before getting them to the launch pads. We want to give the scientists time to pack some critical research notes, the craftsmen to get their tools, the soldiers their law enforcing batons and the leaders - they need time to write hope inspiring speeches. Alas - the scientist has a second cousin that she won't leave behind. The craftsman feels bad about leaving his neighbors. The leader organizes his entire town to storm the launch site and get on a ship. A bunch of people tell a bunch of other people, who grab their pitchforks and attack our chosen ones! Mayhem and despair! **So - how do we tell our chosen ones that the world is ending and convince/force them to come quietly, without extra people? Most likely, without telling anyone else or somehow keep the secret in their close family?** Extra points for getting the chosen guys to agree to go quietly, rather than force them, though force or acceptance through threats is also an option. Bear in mind that sedating 10000 prominent people will be noticed, will require a bunch of implementers to know about the "sedation operation", and might end up pissing the chosen off and getting cold shoulders from them on Mars. So I'd like to avoid such measures, if possible. * "The Government" finds out about the apocalypse a year in advance. * 24 hour notice before the end of the world, no more, no less. * A ship can carry 1000 people and the necessaries-for-survival + their stuff. We have 10 launch sites around the world, one ship per site. * The chosen can bring their close family - one spouse and children (in the process of choosing the chosen, single/newly-wed candidates are given priority over those that are married+lots of kids). [Answer] You can simply lie to them. You can lie in different ways: **Tell them that there's only enough resources for them and their family.** You can embellish if they press. You can come up with very elaborate scientific reasons involving weight, rocket fuel, time constraints, etc. This won't fool the more educated engineers who are well versed in space faring science and determined to do the mathematics themselves, but it will fool most of the people who are coming on the trip. There's a few other less scientific ones that might involve food rations or something like that, but very determined people will insist that they can survive on less to bring one more person. You'd have to combine these lies and make them hard/difficult to disprove. **Tell them that more ships will be made for other people.** No one has to know that only ten are made, and it would be hard to disprove this lie. Google Earth updates its satellite imagery every one to three years, so over the course of waiting the average person won't be able to do their own satellite sleuthing. If they believe that the people will be saved anyway, they're not going to want to insist that they come, especially if this lie is combined with the previous one. **In part of the onboarding process, keep them in a secure location.** In whatever process is made to process the right people and confirm that they are valid candidates for traveling to Mars, don't allow them to leave after the process is done. They'll think they'll go home but they won't be able to. Your government agencies can retrieve their stuff for them, and their distant family/neighbours don't have to really know what's going on. Once in a secure location, they're stuck there until you're ready to go to Mars. **Lie about their destination or purpose of leaving.** - *Thanks to David Grinberg.* You can tell them that they're under arrest. You have some powerful people at play so forging enough documentation to convince the person that the evidence is sufficient for a peaceful arrest without the usage of force is very realistic. You could also tell them that it's a very exotic dream trip or some desired reason based on the research and information you have on them, but some things you say might be suspicious to them, since many appealing trips are often used in scams. You can also offer payment in tandem with this. You could give an initial payment with a promise of a higher payment later in order to gain the person's trust. [Answer] *Disclaimer: much like @Zibbobz, I will completely reframe the problem (and solution).* Not everybody may want to come, some people may even prefer to die rather than abandon their loved ones, and even if you kidnap them, they might just become depressed... and depression will impact their contribution where you have so little resource already. Since you know a year in advance, sell it off differently: the World governments are launching an international Mars Colonization program! * Make it clear that you are looking for specific skills to have a viable colony * Make it clear that you are looking for an heterogeneous society (multiple nationalities, healthy mix of male/female, maybe some children...) * Make it clear that the technology for going back is not available and unlikely to be available in their lifetime and that Earth-Mars communications are never real-time and bandwidth is very valuable so the people coming are basically abandoning any tie to Earth For now, for security reasons, the exact date is unspecified but roughly in XX months; volunteers need apply. Submit the volunteers to physical/psychological evaluations; they *want* to come, they'll agree to pass the tests! You can even get DNA by arguing for the need for "sane" individuals to bootstrap the colony, they'll agree! Make your list of chosen ones; prepare substitutes in each profession in case of defection/accident. Welcome the chosen ones in Earth-based facilities ahead of time, it gives them time to sell/give their Earth-bound wares; after all, you want to avoid stress. It also gives them time to bound together, since you are going to submit them to stressful events going forward, having tight bounds between themselves (and tight knit friend) will be valuable. Finally, since your chosen ones are already there, at the time of departure... embark them and go. --- **At no point before departure do you ever warn them of the impending apocalypse.** None of the non-chosen ones should ever be warned. It should not be possible for any Earth-bound one to sabotage the departed vessel (which you can explain as proofing the vessel against hacking by terrorists, make room for the guys building the proofing on the vessel). The announce will generate anger, probably, however I doubt that you may be able to delay it indefinitely. A good reaction is something to search for during psychological evaluation. [Answer] There's an old, old, old saying about doing something like this: "You can lead a horse to water, but you can't make him drink". No matter what you do, no matter how you coax them, no matter if you even go so far as to kidnap them in the dead of night with gas grenades and sweep them away beneath the chaos, you cannot force someone to go along with you plan just because it's in the best interest of humanity. They have free will, and unless you can control their minds (which would mitigate having to convince them to go anyway) they can always choose not to co-operate. So start at the opposite end - don't look for people to elect, look for people to *volunteer*. Make the idea as appealing as possible - lie if you must - in order to get them to come. Convince them it is their own idea, and get them to stick to it in the worst of times, because that is what you'll have to deal with, and what they'll have to get through to go with you on your plan. You may not get the best of society by doing this, but you will get one important thing: Co-operation. Even if they are disillusioned by what they're given once they're there, they've been made to make that choice themselves. [Answer] Interesting question but I see one flaw. Your *chosen* people are not a monolithic whole. How you treat one of them will not work with another. Essentially you are making the common mistake of trying to treat humans as anything other than individuals, or a least effectively narrow groups. You end up with plenty of options for convincing people (in no particular order) * Explain the situation. If people are logical they may be able to see the necessity. * Lie to get the person somewhere secure * Abduct. For the absolutely needed but unwilling you may have to fight dirty. In any of these cases you will have to restrict communications with the outside world including freedom of movement. Once you get to the site you are locked down until M-Day. And as mentioned in @Draco18s comment you will have to have space for the construction folks who are building the ships in the first place. This should be fine as skilled engineers, electricians etc will come in might handy when building a new home for humanity. [Answer] **Arrest them.** I mean, seriously - this project is already so far into black-ops land (as others have noted, you've just built ten secret interplanetary spacecraft!), so why are we suddenly worried about approval? You show up, you take them into custody (pick a crime; since you have lead time you can probably dig up a Facebook post that can justify it), and you take them to the launch site. What do they bring? Nothing. Tools? Bah - you can have those workbenches fully stocked months in advance. Research notes? Just pull all the hard drives on your way out, let 'em organize themselves mid-flight. If you're softie enough to be bringing kids at all, then let your MIBs be softies and let them grab a toy or two on their way out the door. But everything else? Pre-stocked on the ship. (You secretly built ten rocketships - it's almost insulting to suggest you don't know their measurements). After that, it's simple - you drive everyone in, you put them on the rocket, and you launch the moment the last person is onboard. By the time someone is in a position to complain, you're in orbit watching the apocolypse happen, and then your mission commander can be as apologetic as they like. (And when you just saved their lives, it's a bit harder to be cranky about due process.) [Answer] You don't ever need to force or make them agree when you can simply trick them to voluntary board the ship. When you start to build the ships, you prepare the list of the chosen ones and hire them to build the ship. Since you probably need more manpower to build the ship than the 1000 people every ship can embark, you already have all the people you need, both craftsman and scientist (bonus point: they already are on the site) As crew you select some military personnel from the airforce, which before the launch act as security personnel and you need only a dozen politicians, you and your close collaborators. Here is the action plan: 1. when the building start, you announce that the X best workers will win a place on the ship on the maiden voyage (where X are the number of the craftsmens/scientists you can embark) with the their family, and that the winners will be announced 24 hours before the voyage and before the announce, you will offer a free ride (via military transports) to all the family members of the worker to the site 2. two night before the maiden voyage, the military load all the tools and all the necessary to the cargo bay of the ship 3. for the scientists, you download a copy of their work (and more) from the cloud where you had encouraged to save their work (with some justification) 4. 24 hours before the launch, you announce the winners, randomly choosen, and offer a guided tour of the ship to the others 5. on the lauch date, you simply embark all the winners and leave, for a supposed two days cruise, to never return I agree that you don't really give them a choice, but once the news of the end of the world spreads, they will feel lucky to be alive with they loved ones [Answer] If the government knows a year ahead of time, they have time to shape society so that telling other people is either unfeasible (other people are too far away, you don't have adequate communications technology, etc.), or you just don't care enough about other people to tell them. You state that the chosen ones are notified one day prior, but the government should have been planning for months ahead of time. If the world is going to end, and you have no qualms about making things start to go downhill early, start your own little dystopia just to get the chosen ones in the right mindset. Tank the economy. Quadruple the rate of pollution. Cut off funding for all but the most basic life-sustaining services. Sabotage any high-tech infrastructure people can use to get the word out. Pretty soon, your chosen ones will be so disillusioned with the world they're living in that they won't *want* to tell others about their ticket out. [Answer] If you want to strictly implement the 24-hours-in-advance policy, I would propose the following plan: 1) for each profession, prepare longer lists of candidates (possibly about three to five times longer as the actual amount of specialists needed), sorted by priority of candidates; 2) at the 24-hour-mark go through the list, approach the candidates and ask whether they want to go on your conditions: 2 hours to prepare and gather the people they are offered to take with them and then literally come with the person who approached them. You give each candidate 5 minutes to decide. If the candidate doesn't agree, you approach the next one (and possibly kill the one who disagreed to prevent the spread of information). 3) now you can relatively quickly gather the necessary amount of professionals (honestly, I wouldn't expect the majority of the chosen to refuse ever quite severe restrictions in face of inevitable death). The biggest problem I expect with this operation isn't actually coming from the people on the 24h-list, but from other people involved in the operation for the whole year or a bigger part of it; there is a practically guaranteed possibility of some leak of information, conspiracy, sabotage or riot among people who get to know about the project while it's being prepared. Of course, one would try to keep the amount of informed people minimal and surely one can try to apply the same procedure as above to them but what is possible 24 hours in advance clearly won't be possible months in advance (for instance, killing those who refused to take part might raise suspicion and people who first agreed to take part might suddenly get moral second thoughts). I don't quite see a viable plan of successfully carrying out the preparations up to something like 72-hours-mark. [Answer] Tell each of them that their unique skills and knowledge are desperately and immediately required to deal with a top-secret threat to humanity from aliens. Offer them crazy money/perks/rewards and say that their closest family must accompany them for security reasons (prevent kidnap etc). If they agree, tell them to gather their critical work tools (or tell us where to get our agents to pick them up) and prepare for **immediate** transport. Tell them they are going to a nearby secret base to work with an elite global team, say nothing about the spaceships. Each pitch to each person could be fine-tuned by the worlds best psychologists/negotiators etc months beforehand. [Answer] ## Select a small subset of people chosen for space colonisation. There are far, far more than the 10000 people you are intending to fit on your spaceships. For example, [15000 scientists](http://thecostofknowledge.com/) have signed the Elsevier boycott against poor publishing practices, and UNESCO estimates that there are [~7 million](http://data.uis.unesco.org/Index.aspx?DataSetCode=SCN_DS&popupcustomise=true&lang=en#) researchers worldwide. You still need to account for their families, which realistically means you can only bring ~3000-4000 or so actual Chosen Ones. Under such circumstances, you have lots of space for choice. You can simply disguise your program as a government-spearheaded Mars colonisation attempt (which it would be), and call for volunteers. If your attempt is realistic enough (unlike the [Mars One attempt](http://mars-one.com/en/about-mars-one/about-mars-one)) and clearly has enough funding to succeed, it should attract sufficient volunteers for your mission. In fact, this would likely greatly decrease the pool of married people, which would significantly enhance the amount of manpower on your mission. As many other answers have already pointed out, this is also important because the people *volunteered*. They would therefore be far less likely to sabotage the mission or do other undesirable things that would be likely in people who had been forced into it. Essentially, you don't need to force people, enough people already are able and willing to contribute to the cause, and you just need to find them. [Answer] You have some problems. **The very first and serious problem:** Why evacuate to Mars at the first place ? Our earth, even devastated and contaminated, is still *much* more habitable than Mars. It is still unknown if humans are able to continously live under reduced gravitation with all the ill effects on bone structure and cardiovascular system. All necessary elements are already in place, so we can trust that plants and animals can survive (or, desperately we can chemically create nourishment). Terraforming a planet is something which sounds marvellous, but it is much more difficult than restoring an already habitable planet. The other thing is that life on earth is incredibly resistant. It survived complete glaciation (snowball earth) 2.3 billion years and 600 million years ago and a tropical hell (3000 ppm CO2 in comparison to 400 ppm today) with 25 °C warm water at the poles (!) 100 million years ago. You need some serious whopper, something like a body the size of Mars impacting Earth. So are deep bunkers, provided with nuclear energy, an acceptable alternative ? Another alternative is that you go forward in time where space travel is already highly developed (space elevator has been built) and we have a research station on Mars. Unfortunately earth/other stations are grilled by a 48-hour gamma ray burst and only Mars survives because it is exactly on the opposite of the sun and the source and therefore shielded from the deadly impact. You still want your apocalypse ? Sigh... Ok, those cocky asshole scientists at CERN really did it. They created an absolutely impossible artificial black hole which moved to the core of the earth and grows initially very slow, but exponentially. So people would not realize for a long time what is going on, but the destruction, once feelable, goes very fast. **Second problem:** We need some volunteers. Private coorperations are currently powerful enough that they have billions of dollars available. Bill Gates has enough money to rebuild the Saturn IV and travel to the moon. So you set up a spiffy front company which gives on the outside a slightly campy, idealistic image. You know, a firm with an idealistic dreamer as CEO and a name of "Path to Mars". This firm has its residence at a country which has less worker protection. Now the countries are working together to find the people they need for the project. Those people have now a bad strain of luck: They are fired from their company or their company is going bankrupt. And they are not paid. The processes are taking too long and if the processes are accepted they are losing. They do not get recompensation. Their wives and children are getting desperate. Hit them repeatedly with the **big stick** in the back until they are desparate, too. And then the **juicy carrot**: "Path to Mars" offers them a big deal. The missing worker protection allows now the company to run on them psychological tests to find out as much as possible about them. And you want some margin of error: Employ much more people than necessary to find the best and the most willing. Get them interested with very demanding projects (which, incidentally, are about moving and living on Mars). The spaceships are build at the end of a space elevator. At 36.000 km height even very good amateur equipment is not able to detect such ships. Moving up the elevator could be problematic with 24h, so you need transportation rockets. An Ariane 5ECA could launch 10 000 kg to an geostationary orbit, so you have 100 persons to transport with 200 Mill. $ costs. How do we get the persons on board ? After having the best chosen ones, no discussion: Spice their tea/coffee/whatever with knockout drops. Store them aboard the rocket and bring them on board. Keep them sedated until you started and wake them up before the destruction begins. Show them the end of the earth and explain what you have done and why it was necessary. You can offer them the lock to the space if they want end their life (Smart as you are you have some manpower reserves), the rest will continue the journey. [Answer] **Evil Option** An assumption is made that the couples have been pre-selected at the same time the ships started being built. Another assumption is money is not an issue. **How To Handle the Workers** Insert devices into everyone involved that can kill chemically and but make it look like a natural death. Build an elaborate keyword monitoring system (think Bourne). Lie about the purpose of the ships (think Virgin sky tours). Eliminate anyone who starts to suspect the true purpose. **How to Handle the Families** Insert similar devices into all members of the selected families. Begin the final selection process. Slowly, one by one, tell each of the selected families the truth. Monitor and evaluate the response. At the first sign of disclosure to an excluded member, discount them and eliminate if needs be. This is the future of the human race we are talking about. Only enthusiastic and loyal participants are required for the final program. No-one is irreplaceable. Anyone who does not want to be part of the future or risks the security of the mission does not deserve a place. I see this as being controlled by a fanatic who probably doesn't even believe they deserve a place on the ship themselves. He/she would be motivated solely by the need to preserve the human race. Such a fanatic would also ensure there is no "buying" your way in. The usual political elite need not apply. [Answer] You could tell them that they are part of an extremely important top secret project, to colonize Mars! Or some similar lie. If they do not know that everyone else will die, then they will have no qualms about leaving them. They will probably accept, especially if you offer to take up to nine family members under the age of 40. If they decline your offer, then kidnap them and their immediate family a short time before the launch. But, it is vital that no-one knows of the impending apocalypse. If they knew, then that would cause much unrest and make all of your endeavors more difficult. [Answer] Use tranquilizing darts or neutralizing darts to knock them out, then remove all their papers computers etc and take them to the despatch center. This is probably the safest solution, but may result in problems later. [Answer] ## **Lie, lie, lie!** Convince the whole world we are preparing an epic scientific mission; we are going to start the colonization of Mars. For this, 10 launch sites are being contructed around the earth with their own spaceships. During the **year**, **"The Government"** will feed the press with superfluous information, conferences and technical details. About the last month or so, there will be an announcement for a big drill where several critical aspects are going to be tested: security around the launch sites, transportation of personal and supplies, communications between bases, tv coverage and broadcast, and also how could random people with critical skill be selected to join the mission. When one day remains, the selected group of people is contacted. They were choosen for a specific part of the drill where they will help develop and implement contingency plans, solve critical errors, etc. You offer them a substantial paycheck for a few days of work, and of course their close family is invited to assist with them to witness this historical event. They need to decide for yes or no at the moment their are conectaed, if they refuse you could have some backup candidates or if you think they are essential then a more agressive course of action might be taken (e.g. kidnapping). Vans, choppers, private jets are already deployed and waiting for all this people. Finally, just a few hours before the deadline, all the groups in each of the 10 bases are briefed. You inform the press the last part of the trial will begin soon, as people board the spaceships. There will be a huge surprise when the ships start their rockets and a minutes later all the 10 are taking off. At that point, there will be a press release explaining what happened and giving the bad news of the inminent apocalypse. [Answer] completely different idea ... Secretly assume complete control of their lives using unlimited gov influence and cash. They are all given strong reasons to visit a certain hotel near a sprawling spaceship building yard. These reasons could be mundane things like family holiday, kids wins science fair, "Job requires it & family won free luxury holiday from the booking", fake medical treatment etc etc etc. In every case you would need a reason to get the person of interest and their family there either separately or together.This should be easy to do with unlimited control of employers, banks, schools, media, traffic, telecomms etc etc. You would need to have teams to find and collect all their critical stuff separately. Once they are all in the heavily-secured hotel tell them the truth. The beauty of using an apparently normal hotel is that you can have 1000 separate teams running the scams that don't need to know about each other. They just have to get their targets to room xyz by hh:00 [Answer] The first thing to note is that everyone (except a few iconoclastic geniuses like myself) LOVE to believe lies that comfort them, and will do almost anything to avoid cognitive dissonance, including ignoring very obvious facts and information. If given a choice between learning a new fact that will disturb and challenge their world view, versus a comforting lie that will leave them in their illusions, 99.99% of the human race will eagerly choose the comforting lie. So to "fool" the average person, all you have to do is a) make the truth seem uncomfortable b) give them a plausible but comfortable lie to explain the same facts So to make family members come along (why you want to do this is beyond me, obviously the kind of people who would abandon earth to save their own skins would have little concern for ties to family or friends) don't tell them what is going on. Tell them a comforting lie - we are all going to Bermuda for a free vacation. A different lie for each person. Tell them its secret hush/hush government stuff, they don't want any trouble, no one wants any trouble. Get them to pack. They get on the plane. Oops, to pick up our free vacation voucher we have to get in this space shuttle for a minute. Oops, we launched. Do what all the elite do to you night and day - lie. How do you think they are stealing $3 trillion a year from the taxpayers without even a peep of protest? How do you think the elite live like kings, like princes, nay like gods, all at your expense, and you have never raised a peep of protest? That's what they are doing to you RIGHT NOW. And you are cooperating. You are eagerly cooperating. You are 100% invested in the illusion. make the truth seem uncomfortable. No one will ever believe it, even if presented with solid proof. [Answer] Wow, seeing the answers you get... So many people believing in lies but I am sure lot's of them despise lies... Don't you all think a "new start" would be better of without tricking people that would be chosen? They are presumably smart/smarter then you so their reason levels are hopefully / probably higher then yours. Yes we do have loved ones but either bring some along if they also have skills or they will themselves decide if they want to go while their loved ones make the sacrifice to stay. At least that will motivate them to succeed and work more, and with lies and tricks you gamble on making them angry, non cooperating, apathetic, depressed. I agree about lies or maybe hiding plans to general self-centered public but actually I don't think you would need any more/less security then now. Don't do like politicians do...they don't see further then lies. ]

[Question] [ **How might a carnivorous tree look or work?** The following conditions must be met: * Consumes members of the biological kingdom 'Animalia' * Possesses something resembling a trunk or stem of any kind * Possesses something resembling branches stemming from the 'trunk' * Is apparently rooted to the ground Challenge conditions: * Exclusively consumes water, minerals and members of the biological kingdom 'Animalia' * Possesses something resembling leaves or needles * Visibly reacts to seasonal change * Reproduces via seeds * Reproduces without making physical contact with other members of its species * Does not appear to move on its own accord [Answer] There are trees which are capable of killing large animals, in fact, only they don't eat them afterwards. But it's a start. [](https://i.stack.imgur.com/37etV.png) *Pisonia brunoniana* is known as the birdcatcher tree for a reason. The seed pods of this tree are coated with a mucus which traps insects - even this alone could evolve into carnivory, but wait till you hear what happens next. These trapped insects entice seabirds to come and feed, but as they do, they get covered in seeds. These seeds are very sticky. As more and more of them latch onto the bird, they weigh it down, and clog up its plumage. Unable to fly, the helpless victims later die of starvation. Birds of prey, attracted by the corpses, often too get covered in the vicious seeds of the birdcatcher tree, and they too later starve. So, how can we work with this to make a carnivorous tree? Let's have the sticky sap coat the tree's bark all over. Insects of course will get stuck in this all the time, and they shall be slowly digested by enzymes in the sap. While this happening, birds will come to eat the insects and also get stuck to the trunk. Any bird which tries to perch on a branch will get stuck, as will the likes of monkeys, squirrels and other arboreal critters who mistake it for a normal tree. The mucus/sap would be transparent, so that the killer tree would resemble a conventional one in all respects - aggressive mimicry. You could also have the sticky substance coat the roots too, to snag any passing soil fauna. **TL;DR: It's a sticky tree.** [Answer] # Rule 1: Don't feed like a tiger, feed like an alligator. Alligators (and several other animals) eat only rarely: they can sustain themselves on just a single large prey animal every year, or even every two years, because they move slowly and don't use up much energy. Trees are great at moving slowly and conserving energy! That means that your particular tree doesn't need to hunt, it just needs to make sure an animal dies nearby often enough to have a few meals every once in a while. Once you've settled that, I propose one of two approaches, both of which allow for a totally regular tree, save for some small differences that still meet all your requirements. ### Pit-y The Fool Pit traps are an ancient human tradition, are used by antlion larvae, and, naturally, are used by pitcher plants. Making a pitcher plant tree-sized is tricky, since hollow structures aren't as stable, so instead, your tree grows *over* a pit trap. Its roots encircle a large, underground hollow, which it fills with a similar digestive fluid to pitcher plants —if we want— or just plain old water, if we don't. On the surface, its roots make a fine web that covers the otherwise open pit. The tree's own leaves fall and accumulate on top of it, disguising the unsafe ground. Along comes an animal, it steps on the leaves, and plunges down into the pit below, with no way to escape. There, it either drowns or starves, and its body either is dissolved by the digestive fluids or decomposes to nourish the soil the tree grows in. ### When in doubt, violate the Geneva Convention If you're a person with a pollen allergy, you may believe that trees are already nearly killing you... [](https://i.stack.imgur.com/VXNdn.jpg) And that's when they aren't even trying. Your carnivorous trees are ordinary trees in every respect, but their pollen is toxic (there is prior art here with the death camas). Once a year, in a forest of your carnivorous trees, a vast cloud of chemically lethal pollen boils off of your trees, killing hundreds of animals that have made the area their home. Of course, you would think that this would end up eliminating local populations to nothing, but in fact, the death pollen tree has developed a precarious balance, where its pollen is just toxic enough to only kill the *old, infirm, or sick* animals in its groves, while leaving the young and healthy ill for only a day or two, a sort of yearly reaping. In this way, it cultivates a very healthy, thriving ecosystem of animals, by making sure that only ones of reproductive age and viability live in its environs. If you want to make them a little more literally carnivorous, take a page out of the book of *Ophiocordyceps unilateralis*, and have the toxin compel the dying animals to seek out the trunks of the trees that killed them, to slowly expire among their roots. This could be done with either hand-wavey toxins, or by saying that the pollen is lethal because of a symbiotic relationship with a bacteria that induces that behavior. [Answer] **Carcass tree.** [](https://i.stack.imgur.com/dUpli.jpg) The tree has a commensal relationship with large predators. The predators use the tree as a refuge to eat their kills safely. The tree gets the leftovers. The tree has hollows in which scraps and offal land, and from there the tree puts forth adventitious roots. The tree exudes pyrethrins, poisoning the meat for flies and so the tree gets the fly larvae too. The pyrethrins are good for the large predator - they smear on its coat and kill fleas and ectoparasites. Plants generally reproduce without physical contact - they have pollen. There would be a hurdle for these trees - how to get to adequate size to shelter leopards and start the meat coming? You could posit and earlier stage in the life cycle where the tree uses photosynthesis, but why give that up as an adult? We will take a page from the playbook of the strangler fig. [](https://i.stack.imgur.com/IwHL5.jpg) The plant intermittently makes meaty fruits that smell great to leopards. The leopard poops out the seeds near trees it likes. The carnivorous plant wends its way across the ground to take advantage of carrion dropped from the tree and then climbs the tree as a tiny vine. Gradually it encompasses this tree, and becomes the tree. [Answer] I'd suggest [pitcher plant](https://www.youtube.com/watch?v=1CP1i0UKvb8) style, the stem is hollow and full of sweet nectar that attracts small creatures. There are arguments about whether pitcher plants are strictly carnivorous as some suggest other options, but for the purposes of this question, we'll assume they are carnivorous. Since the requirement to not move on its own accord prohibits various entanglement or venus fly trap style options, pitcher is probably the best way to go. A tree with a hollow trunk, full of water containing a mild anaesthetic or sedative, this causes trapped creatures not to struggle too hard to escape which risks damaging the tree. Most carnivorous plants are primarily plants, whatever additional nutrients they gain are just that, additional, they're capable of surviving without them but it helps. This means that all the normal aspects of a plant are present; roots, leaves, flowers, seeds. Your choice of pollination mechanism, whether insect, bird, wind or otherwise. Consider perhaps something like an oak tree, the acorns on the outer branches are good eating for squirrels, and come the season they appear in vast numbers, but sometimes the acorns only appear on the inner branches, over the trap, and these ones are drugged. Beware little squirrel, when and which acorns you try to take. There's no way out if you fall in. [Answer] **Venus Flytrap** [](https://i.stack.imgur.com/VAYt8.jpg) <https://en.m.wikipedia.org/wiki/Venus_flytrap> Perhaps the most obvious starting place, the venus flytrap is a plant with “jaws” that slam shut like a bear trap when the hairs on the inside are moved. Typically it requires several movements within a certain time frame in order to trigger the jaws to shut (so the plant knows that the thing inside its jaws is a creature and not a leaf or debris). Once closed, the jaws fill with a digestive fluid which breaks down the prey. Applying this to your tree, there may be giant jaws like those of a venus flytrap scattered around the base of the tree. The jaws would be connected to the tree via an underground stem which runs from the jaws to the base of the tree. The actual tree portion looks pretty normal, perhaps mimicking other trees via interbreeding or simply evolving to look like, for example, a common oak tree or a fir tree. This has been seen in both snakes and insects where one species evolves to look like another. **Sweet, Delicious, Poison** Your tree may evolve poisonous fruit, slowly killing any large animal that ate it. In fact, [apple seeds have cyanide in them](https://www.medicalnewstoday.com/articles/318706.php). Well, to be more specific, they have a compound in them called Amygdalin that breaks down into hydrogen cyanide. > > Amygdalin is a part of the seeds' chemical defenses. It is harmless when intact, but when the seeds are damaged, chewed or digested, amygdalin degrades into hydrogen cyanide. This is very poisonous and even lethal in high doses. > > > The fruits of your trees could contain far more Amygdalin, perhaps the entire fruit is laced with it. When a creature bites down into the fruit, the compound would start to degrade into lethal amounts of hydrogen cyanide and kill the creature relatively quickly. The fruits should have some sweeteners in them as well to encourage an animal to chew and swallow the fruit, making the poison more effective (i would imagine, based on apple seeds, that Amygdalin would make the fruit very bitter. By adding sweeteners, such as high amounts of sugar, this could help to mask the taste). Once dead, the animal would start to decompose, providing nutrients to the tree. Scavengers may also be killed indirectly by consuming part of the poisoned creature. By eating the cyanide filled carcass, the scavenger in turn would be poisoned and die, providing more nutrients to the tree. All of a sudden this makes the story of Snow White eating a poisoned apple and dying make sense, and gives it a much darker tone. **You May Feel a Little Pinch** As one of your challenge conditions is to have the tree covered in “something that resembles leaves or needles”, i propose something similar to Nettles. These are brightly green coloured plants covered in hypodermic needles that inject toxins into a creature that touches them. You could have something like pine needles, found on pine trees, which function in a similar way. These needles could inject a toxin into an animal that touches the tree, quickly killing it. It may be hydrogen cyanide, as mentioned earlier, but to spice things up a bit i’ll also add in neurotoxins. These are toxins that affect the nervous system, your trees could paralyse its prey or give it a heart attack, killing the creature. Again, it would slowly decompose and provide nutrients to the tree. Any creature that got near risks touching the tree and being killed as well. **Vicious Vines** [](https://i.stack.imgur.com/zZ2jd.jpg) <https://www.bowerandbranch.com/t/192/niobe-golden-weeping-willow/> Simply because i love the idea of the leaves from a willow tree triggering some kind of trap. When a creature passes through the vines, it causes the tree to release toxic chemicals to kill said creature, perhaps in the form of pollen or some kind of gas or mist released from the tree. The tree may have some internal requirements to trigger the release of its poison. For example, a small section the leaves parting and closing again with no other movement for a short period of time. This would prevent premature triggering due to the wind or debris. The leaves may also only grow a certain length, allowing very small animals to pass underneath and not trigger the trap (as it may be more effort than its worth to poison a single squirrel, for example.) However, larger animals would still trigger it as they are too big to go under the leaves. *Also, quick reference to Nausicaä, Valley of the Wind* [](https://i.stack.imgur.com/zByfm.jpg) Whilst not carnivorous trees, the plants release a toxic spore which kills any creature that inhales it. This idea could easily be translated to create carnivorous trees. [Answer] Like Liam Morris, I have always liked the idea of willow trees that trap prey. My mechanism of choice would be that the hanging leaves and branches are covered in a stringy sap that works like a spider's web to trap small animals. The more the animal struggles the more enmeshed they become and the tree then grows tendrils into the trapped prey to extract nutrients. While the trees do not voluntarily move, the additional nutrients they gather from trapped animals could allow them to grow tendrils quickly and begin extracting nutrients within minutes of the animal being trapped. The sap would likely need to have some sort of narcotic effect so that trapped animals do not continue struggling. If the pollen has a similar effect it would serve the tree by causing nearby animals to be careless around it and more likely to be trapped. The effects of this sap and it's medicinal (or recreational) value could be useful to a plot or side plot, if you want to go there. The tree stays disguised as a normal willow because branches with trapped prey will naturally sag downward and inward due to the weight of the prey, concealing them inside the "tent" created by the exterior foliage. This combined with continually growing new leaves around the outside leaves the tree appearing to be a normal willow unless you know exactly what to look for. Strip away that exterior tent of foliage and the scene would be a macabre one with numerous animals in various states of decay and a pile of bones on the ground below. [Answer] I like the image of a Willow tree, but I'm picturing a more pro-active version that has branches that work like a jellyfish's tentacles (search cnidoblasts). if an animal contacts them they reflexively trigger with a similar hair mechanism to a Venus fly trap, binding and coiling the prey, perhaps injecting a sedative, with the whole branch contracting to bring it closer to the trunk. It might be fun to add a symbiotic relationship to draw in prey. I'm thinking a cloud of little bio-luminescent fairy-flies that feed off sap from the trunk of the tree but are too light to trigger any of the stingers. At night their light attracts in other larger animals looking for prey. Make the light blue and you have a Willow that Weeps for it's prey. [Answer] This doesn't fill the challenge criteria, but a giant frog with a sticky tongue would be a cool base. [](https://i.stack.imgur.com/pagnG.jpg) It would have a metabolism like a large snake, slowly digesting its prey. It would have evolved to mimic bushes in the surroundings, maybe just hiding within them and evolving camouflage features like coloration and patterning, later bushy shapes on the head and such. It would sit quiet for months, then suddenly opening its mouth to attack an animal (maybe human) with a giant 20-foot tongue, retracting the prey into its mouth in a split second. For extra effect, you could have it needing to chew its prey, but trying to keep it quiet when it hears movement around. [Answer] Not quite a tree, but there is a [bush](https://en.wikipedia.org/wiki/Puya_chilensis) that does something similar - it initially evolved exposed roots above-ground to stop herbivores (namely sheep) from reaching it. It then evolved spines on those roots to better stop sheep - it catches their wool, and they're then trapped, and starve, turning into tasty nutrients right over the roots. The bush just needs to evolve actively trying to attract the sheep to become 'truly' carnivorous. [Answer] Huge, dark tree, that likes to grow amidst other huge dark trees. From below, it looks like any of the others, but in truth it grows like a bent-down rod(back to a few meters above ground ) ending in one row of wide horizontal branches (though hiding it well in a thicket of leaves) forming an umbrella-like structure, spring loaded to snap shut. The seeming lichen hanging down are the triggers. A critter passing below fits the prey profile? the umbrella snaps shut around the victim, and the whole tree springs straight, yanking the prey (prey size determined by tree size, adult trees swallow elephants every few years) into the air. Thorns and spiny protrusions will inject highly corrosive substances deep into the victim, who proceeds to trickle-down the tree over the next few days. Then begins the growing and reloading, taking months. ]

[Question] [ I have a problem with too many men suffering from alcoholism in my country. I tried putting large taxes and limiting the stores that sell alcohol but that led to cottage industry of low quality moonshine sold on the black market. Quote often with even worse effects. Could you recommend some ways to decrease alcohol consumption? [Answer] (I guess since I got the comment upvotes I'll post it as an answer...) Look at studies of Portugal and its decriminalization of hard drugs. Far better than anything we've found so far is the institution of social programs that help rehabilitate those who are suffering for little to no cost. Prohibition NEVER works, but legalization coupled with a strong socially accepting message does. Alcoholism is a recognized disease and needs treatment, not punishment. [Answer] Engineer a medicine, drug, bacteria, virus, or gene therapy, introduced into the food/water/air supply, that results in an intolerance to alcohol, similar to lactose intolerance or ipecac syrup. Alternatively, a bacteria that is highly effective in rapidly breaking down ethanol so that no one can get drunk off of it. Both methods intend to make drinking alcohol much less enjoyable, by either increasing its negative consequences or negating the positive effects. Either method is a logical public policy similar to introducing Fluoride into the water supply, or adding bitterants to anti-freeze to make it unlikely for kids and animals to drink. A significant epidemic of alcoholism can make such an effort supported by the public. Or do it covertly. [Answer] **Give them another way to be happy** Whether or not they suffer from alcoholism, people drink because they are not happy. Drinking is a short term and potentially hazardous solution but it is a solution nonetheless. You cannot take it away and hope for improvement if you don't offer something to replace it. Get your populace "addicted" to any of the below. **Physical activity:** Formal or informal sports, working with animals, wilderness survival (think scouting). All give an excuse for physical activity. This provides the same dopamine and seratonin high that alcohol provides with none of the drawbacks. Except maybe addiction. People can get addicted to competitive sports but that's not as big a problem as addiction to drinking. **Aside:** Drinking is bad for your health and is not advised for serious sportspeople! Another reason not to drink. **Other drugs:** There are other drugs that provide a similar high but are less addictive and have less side-effects. One answer suggests cannabis. I'm not here to debate the pros and cons of cannabis over alcohol, since you are free to make up your own smart-drug and decide the effects for yourself. But four things you must decide are strength, addictiveness, side-effects (effects besides the high), and strength of withdrawal. Can you die from alcohol withdrawal? Can you die from cannabis withdrawal? **Communal activity:** Social interaction and working as any sort of team also gives a serotonin/dopamine high. One answer suggests religion, and I agree. However it cannot be the monastic type of religion. If must be load and evangelic and involve teamwork. The religion forces you to work with people you otherwise wouldn't and that is its advantage. [Answer] Make [common ink cap](https://en.wikipedia.org/wiki/Coprinopsis_atramentaria) a staple dish. Common ink cap is a common and edible mushroom. It contains a toxin that is not dangerous in itself, but it prohibits proper break down of ethanol, resulting, in mild cases, in immediate and extremely severe hangover, and in bad cases cardiac arrhythmia. It is *extremely* unpleasant to drink alcohol for several days after ingesting the mushroom. [Answer] [**Disulfiram**](https://en.wikipedia.org/wiki/Disulfiram) (tradenames: Antabuse, Antabus) in the water supply, or possibly in the air. It basically causes *immediate* hangovers by inhibiting an enzyme that finishes the degradation of ethanol. It's discovery was something of an accident, if I recall correctly. Workers in rubber manufacturing plants where products were being vulcanized (disulfiram has a sulfur-sulfur bond that's presumably useful) began to notice intolerance to alcohol after work. I don't know if they were getting it on their skin and it was being absorbed, or if the high temperatures were aerosolizing some of it and they breathed it in > > Disulfiram plus alcohol, even small amounts, produce flushing, throbbing in head and neck, throbbing headache, respiratory difficulty, nausea, copious vomiting, sweating, thirst, chest pain, palpitation, dyspnea, hyperventilation, tachycardia, hypotension, syncope, marked uneasiness, weakness, vertigo, blurred vision, and confusion. In severe reactions there may be respiratory depression, cardiovascular collapse, arrhythmias, myocardial infarction, acute congestive heart failure, unconsciousness, convulsions, and death. > > > It was featured in [a story](https://www.marketplace.org/2011/03/03/world/russia-rx/killer-cure-alcoholism-russia) between Radiolab and Marketplace where some Russian clinics used it to scare people out of alcoholism. Maybe the view of alcohol in your society is more akin to the Russian sentiment than it is in North America. > > **Kai Ryssdal**: Alcoholism and Russia have a long and destructive history together. Alcohol abuse costs that country half a million deaths a year, most of them men of working age. It also costs billions of dollars in lost productivity. Male life expectancy in Russia is just 60 years, and the Russian population is predicted to shrink nearly 20 percent by the middle of the century, in part because of the drinking. Every problem, though, creates a market for a cure. > > > Our health care correspondent Gregory Warner traveled to Moscow to track down one very popular cure -- and the doctors who sell it. > > > **Gregory Warner**: For me, this all started with a story I heard about a friend's ex-boyfriend. A Russian alcoholic who promised he'd never ever drink again. Story was he got a capsule surgically inserted under his skin. Some kind of chemical compound, such that if he drank that capsule would explode into his bloodstream, and kill him. > > > [...] > > > Eugene Raikhel [professor at the University of Chicago] says if it worked it's partly because Russians understand addiction differently. > > > > > > > **Raikhel**: Here's the distinction: in North America, the prevailing understanding of addiction is it's not about the substance as much it is about the face that you're out of touch with some truths about yourself and your condition. > > > > > > [Whereas in Russia,] Many of the patients I talked to say, "I don't have to change myself in any way, I don't have to become a different person." > > > > > > > > > I just have to get rid of my addiction. Which is what Dr. Davidov offers. When he gives you that pill and he puts that drop of vodka on your tongue, he scares that part of you into submission. > > > — [The killer cure for alcoholism in Russia](https://www.marketplace.org/2011/03/03/world/russia-rx/killer-cure-alcoholism-russia), APM Marketplace, 3 March 2011 > > > [Answer] ## Use tactics that have been successful in reducing smoking In the United States, smoking tobacco has been on the decline. [This New York Times article](https://well.blogs.nytimes.com/2013/06/25/why-smoking-rates-are-at-new-lows/?_r=0) explored how the most effective methods involved decreasing access to cigarettes (especially due to finances) and limiting public exposure. Also, these were gradual changes over time, not an immediate ban as happened with the US alcohol prohibition. ### Educate people about advertising tactics used by the industry, with the goal of giving them a negative perception of it > > But educating people about the tobacco industry’s marketing efforts can have a big impact. “We now have empirical evidence that people who don’t like the tobacco industry are about five times as likely to quit, and a third to a fifth as likely to start,” [Dr. Stanton A. Glantz] says. > > > Anecdotally, I see this technique used heavily in my area, with an ad campaign of "big tobacco targets kids" to create a negative perception of the industry. ### Ban the substance in public locations > > [Dr. Glantz] also notes the importance of smoking bans. “When you create smoke-free workplaces, bars, casinos and restaurants, it sends a strong message that smoking is out,” he says. “It also creates environments that make it easier for people to quit smoking.” > > > Also, fine those who violate this > > [Dr. Mary O’Sullivan] says that many of her patients who are trying to quit head to city parks, where it’s been illegal to smoke since 2011; people caught smoking in parks face a $50 fine. > > > ### Reduce substance use in movies and other popular media, and increase negative portrayals > > According to these experts, also at play may be increasingly graphic ad campaigns, including the “Tips From Former Smokers” campaign begun last year by the Centers for Disease Control and Prevention and fewer incidents of smoking in popular movies. Research shows that the more times a young person sees smoking in the movies, the more likely he or she is to take up smoking, and from 2005 to 2010, young people saw far less smoking in PG-13 movies. (Many of those youths are now adults and would have been captured by the new report, though smoking in movies has since increased.) > > > --- ## Stuff that needs more research ### Increase the price of the substance at retail locations via taxes This has been a very effective tactic for reducing smoking, but you said that it had already been tried for alcohol. More research needs to be done to see if this would work if the other methods listed above were implemented. > > Richard Grucza, an associate professor in psychiatry at Washington University School of Medicine who studies tobacco policy, cited the 62-cent-per-pack federal tax increase that took effect in 2009, as well as laws that ban indoor smoking, cigarette vending machines, the sale of packs of fewer than 20 cigarettes and the distribution of free cigarettes, as major contributors to declining smoking rates. > > > In other words, increasing the tax, outlawing distributions of small quantities, and banning official distribution of free cigarettes worked together to make it more expensive. and > > [Dr. O’Sullivan said,] “In New York, we’ve gotten it down to 14 percent, and one of the big reasons is price. Here it’s $12 a pack. Even our schizophrenia patients, who are the most addicted, who used to smoke two and three packs a day, even they are smoking less because of the price.” > > > ## Stuff that probably won't work ### Don't rely on school education programs These turned out to be less effective than other methods. > > School education programs, for example, don’t appear to be very effective, most likely because schools are difficult places to change social norms and it is hard to do the programs well given all the other demands in the school day, [Dr. Glantz] says. > > > Also, to my knowledge, there are no current efforts to prevent someone from growing their own tobacco or consuming it on private premises. These tactics were not effective for prohibition of alcohol in the US, so a society trying to reduce alcohol consumption would do well not to try. [Answer] **Legalize marijuana.** Some people want to feel different. Like your men. MJ lets them scratch that itch. Weed is safer than alcohol in the short and long term: less organ damage, less potential to die of overdose or withdrawals, less aggressive behavior. People don't suffer from hangover related effects the next morning: less missed work. Marijuana is a superior recreational drug in comparison to alcohol. The US is in the middle of an experiment about this. It is too soon to know for sure if legal MJ will really reduce alcohol use but one can hope. Here is Time stating beer sales are down in places with legal marijuana. <http://time.com/money/4592317/legal-marijuana-beer-sales/> [Answer] Prohibit anyone other than the government from selling alcohol. Put your government alcohol outlets in dingy warehouses on out-of-town industrial estates, staffed by civil servants who have customer service skills that are too poor for them to work anywhere else. That is pretty much guaranteed to make alcohol deeply unfashionable, while preventing large-scale black market sales, since its availability from the government will cap the prices that black market dealers can get. [Answer] Give people a chance to succeed. Keep corruption under control, and provide opportunities for education that leads to meaningful work. There will always be a few people that will turn to drug or alcohol abuse, but seeing the potential to have a meaningful future is the best deterrent substance abuse. [Answer] Up the penalty for consuming alcohol to death by being flayed alive in the public square along with five, randomly-selected family members, with a guarantee that whatever family member(s) reports them prior to their arrest will be spared. Further, when the government catches moonshiners, give them methanol-tainted moonshine to distribute to all their customers (which will kill them painfully.) In return, give any moonshiner who succeeds in causing a noticeable uptick in methanol poisoning in his area a swift execution instead of a painful one, and spare his family. Expect people to turn to other intoxicants instead of alchol, but you didn't say anything about that. Do note that figuring out *why* people are consuming excessive quantities of alcohol and addressing that issue will solve the problem with a much lower body count, but it will also take government officials who are actually competent, whereas the proposed method merely requires finding a core group of vicious psychopaths and giving them license to hunt. [Answer] There are several reasons for alcoholic consumption, and so there are several ways to stop it. The main reason for alcoholic consumption is people being not happy with their lives, people who are homeless, idle and that are maybe in recent breakups, or recently lost someone they loved, are the most to be drinking alcohol, and so to reduce it, many regions have tried putting a fine on drinking, which clearly didn't work and in some cases, completely backfired. So, seeing the reason they are drinking, the best way of making them stop drinking, is by fixing their lives, not telling them to stop, but making them stop, by maybe increasing physical activity, social interaction, etc.... This seems to be clearly the best way to stop alcoholic consumption in whatever region or place. [Answer] Simple answer - put heavy fines on making moonshine. Make sure this is enforced, and make sure police are kept on the alert about this. ]

[Question] [ In this case, a person from a world similar to ours, at a time and technology roughly equivalent to our 14th century, but with magic. Through some odd spell, this person was teleported far away from home. They think it is to a different region in his world, but rather it is a different world entirely, ours. I want to know where in our world this traveler could arrive that would take them roughly a week to notice significant differences in technology. That means not in the middle of Beijing, but also not in the middle of the Amazon. This person is from a world where magic is relatively common, think your generic D&D fantasy world. That means the average street light could be explained with magic, and maybe a car or plane, but not a lot of these. Not everyone had magic where they come from, so a lot of cars would make it clear. Large buildings would give it away, as would televisions or anything else shockingly different from their time. The transportation itself is nearly instant, and will have no physical or mental effect on the traveler, other than bewildering them that their surroundings have changed suddenly. They do not know what is happening with the spell, so it is likely that they will take a few seconds to figure out what just happened, then proceed with normal behavior for one who finds themselves lost wherever it is they are. The traveler is from a culture similar to Western Europe, but they expect the spell to have taken them to elsewhere in their world, so a different culture wouldn't necessarily give it away. They were an adventurer, so assume survival isn't an issue, as they will have supplies and survival experience. I'd like to collect situations of the traveler interacting with people, and being on their own in the wilderness. (This is for a game with variable starts) [Answer] [Pennsic](http://www.pennsicwar.org/penn45/GENERAL/photos.html), so long as your traveller doesn't make it up to the parking lot. Pennsic is a two-week-long [SCA](http://www.sca.org) event. It's not a re-enactor event where everything is correct down to the details; you'll see sneakers, nylon tents, plastic armor, and cell phones amidst the authentic clothing styles, pavilions, chainmail, and more. Without the magic angle nobody would be fooled for a minute, but *with* it, it sounds like you can dismiss smaller exposures of modern technology like you see there. (A ubiquitous modern artifact is eyeglasses; these were actually [invented in the 13th century](https://en.wikipedia.org/wiki/Glasses), though they were not stylish and lacked earpieces. Your traveller might chalk that up to local variation, same as some of the [sumptuary laws](http://tasha.gallowglass.org/sca/sumptuary.html).)  The SCA covers a broad time range up until 1600. However, most of the clothing you'll see at Pennsic -- and clothing is one of the first things people will notice -- is earlier and would not be jarring to a 14th-century traveller. Given the weather, simple tunics (common for many centuries) are common during the day; in addition you'll see Viking, high-middle-ages, cotehardies, shirt/doublet/hose, chemise/skirt/bodice, and a fair bit of Italian-renaissance clothing. (For an overview of 14th-century clothing see [this Wikipedia article](https://en.wikipedia.org/wiki/1300%E2%80%931400_in_European_fashion).)  If your traveller goes to the battlefield he'll see people with a range of medieval armor and weapon styles competing in [tournaments](https://en.wikipedia.org/wiki/Tournament_(medieval)) that will be not unfamiliar to one from the 14th century. He might wonder at the absence of horses, and about weapons of wood rather than blunted steel, but he'll know that the object isn't actually to kill people so I believe he'll consider it an acceptable variation.  Now as I said, not everything at Pennsic is historically accurate, nor is a single historic period represented. There are [places within Pennsic](http://www.pbm.com/~lindahl/cariadoc/enchanted_ground.html) where extra effort is made to stay in period, with nothing modern being visible or discussed unless absolutely necessary. Pennsic is a large festival gathering people from many places near and far. Differences that we know to be from different times could be seen instead as coming from different *places* -- those people with that particular style of dress aren't from the 15th century (which hasn't been invented yet) but from a place called "Meridies". This is, in fact, how SCA participants who try to stay in persona explain a Tudor interacting with a Viking, for example. If your traveller arrives several days after the start of the event, everything will be in full swing. And after a week of settling in, suddenly everybody will pack up and leave, which will start with processions of cars to camp sites to pack up. Your traveller will be forced into the modern world at that point. Two caveats: First, more than 10,000 people attend Pennsic. They have to get there somehow. There is a vast parking lot full of very modern cars. If you can arrange for your traveller to land down in the bog, under the trees down by the lake, he might find the parties attractive enough, and the climb up the hill to the parking lot onerous enough, to not go there. Second, just about every year at *some* point, small planes or helicopters from a nearby army base buzz the camp. It usually only happens once or twice for a few minutes, so your traveller might marvel at the strange, magical, loud creatures of the sky. But aside from that, the largest buildings on the site are two-story houses (and similar structures) and a barn. There is a convenience store with refrigerator sections, but no visible televisions. [Answer] Somewhere in the Rockies, or the Canadian wilderness, about a week's hike from town (closer than a week straight-line distance to allow for some wandering) with enough sufficiently obvious natural resources that the traveler will be physically OK, and enough topology to get high enough for a view to know where some town/city is or (for fewer clues about advanced tech) at least to find moving water he can follow downstream to a town (helping with knowing which way to go). Even if a rare overhead flight were noticed (through a break in the clouds, if needed), the traveler might assume it's a migratory bird or explainable through magic as noted in the question. "Flying metal tube with fixed wings containing hundreds of people" would likely not even be guessed at. However, if you wanted to avoid overhead flights, [this question](https://travel.stackexchange.com/q/137619/31076) is for you. [Answer] You may consider sending that person to the USNRQZ ([United States National Radio Quiet Zone](https://en.wikipedia.org/wiki/United_States_National_Radio_Quiet_Zone)). It should be noted that the USNRQZ would still seem to be the future for a person from the 14th century, but if we can explain some of the stuff with magic it may pass… The area is mainly rural low residential scattered by forest and mountain. There are two arcane structures known as the Green Bank Telescope※ and the [Sugar Grove U.S. Naval Radio Station](https://en.wikipedia.org/wiki/Sugar_Grove_Station), which is a restricted area for most people, except the wizards people that work there. [](https://i.stack.imgur.com/ki4RU.jpg) ※: Green Bank Telescope, part of the [National Radio Astronomy Observatory](https://en.wikipedia.org/wiki/National_Radio_Astronomy_Observatory) The area is devoid of any source of interference for the radio observatory such that cell phones, television, microwaves, etc. So, people don't listen to radio, don't watch television, don't use cell phones. Telephone land lines are restricted; intead telephone booths are used. Any electronic device must be aproved for use in the area. Computers would be hard to come by. Some radio frequencies are allowed but only at low power. There are cars, but only diesel engines are allowed, and there are no traffic problems. Also, with most people working at home means there is no commute. But you may spot tractors on daily use. And of course, there is electricity, which is used mainly for illumination. --- This is not as drastic as sending the person to an Amish community. Amish won’t use television, radio, computers, or telephones. They don’t own cars — buy may hire people who do. They don’t drive tractors for that matter. There is restricted access to electricity. Although there are battery powered calculators, flashlights, ventilators and similar appliances. [Answer] Backwater provinces in Afghanistan, such as Helmand. It's a tribal, agrarian society that would be recognisable to Alexander the Great if he passed through again. There is very little technology, and even electricity has not fully permeated all the villages. Literacy is below 10%, and the figure of households with clean drinking water is similar. Roads are unpaved, and vehicle traffic is a combination of donkey carts and motorcycles ('iron horses'?). Dwellings are mud/adobe compounds. Farming is done on family smallholdings by means of hand-cut irrigation ditches and ox ploughs, etc. Mobile phones are used...2G/GSM-only style for the most part. Potentially explicable by magic, but also a possible hook for further technological discovery by your time-traveller. There are quite a few firearms, however. Again, not necessarily a complete immersion-breaker; and the Taleban/ISIS vs Afghan authorities dynamic might create an interesting threat environment for your protagonist to navigate. I'd keep him away from market towns, though, as these are considerably more modern. Another possibility is to drop him in a Kuchi nomad camp in the same area: these guys travel in camel caravans along the Silk Road area in much the same fashion as they have done for centuries (with a couple of extra AK47s). They could even pass through one of the villages mentioned above, before winding up in a market town... [](https://i.stack.imgur.com/WgM3J.jpg) [](https://i.stack.imgur.com/j2CGV.jpg) [Answer] I think the Amazon rainforest will be a good place. There are still native tribes that are quite isolated. [Answer] An Amish community? Let's do the time warp agaaaaain! Or inside a container on a container ship with some illegal immigrants. Which would be crazy if they woke up one day and some new guy was there. Or on the vast estate of some eccentric rich dude who likes to kick it old school. Or in a deep subway tunnel where some homeless people live. (Like the movie Dark Days.) Or in an insane asylum or prison where the guards just don't give a f\*ck who is in there. Or Guantanamo or some other military base where they will definitely keep him under lock and key for a little while. Or Supai, Arizona. No cars! But probably satellite TV. I think a lot of these would be easier to explain if he transported naked, a la Terminator. [Answer] You seem to be looking for situations where the traveler will encounter people, but not modern technology. This essentially means you are looking for places away from civilization where the people, for some reason, do not have any modern items. It is worth considering that many modern things don't look modern, and we also still use a lot of ancient technology. One rule of thumb you might use for your story is that anything with printed text or interchangeable parts would give away the modern era and fascinate your traveler. In order to avoid modern technology completely, you will mostly need to think about people who choose not to use modern technology. These might include: * survivalists * historical reenactors * various religious societies or monasteries * uncontacted tribes * contacted tribes who have resisted change * shipwrecked people Another possibility is contact with modern technology that is not obviously modern, or would take time to distinguish from magic. These might include: * an overgrown nuclear fallout zone * the Forbidden City in the middle of Beijing * Disney World * trapped in a construction site atop a skyscraper * special ops/recon training area * Montana [Answer] ## A third world remote island I lived one year in this kind of place ([more exactly, there](http://banyak-island-bungalow.com/access.html)) Of course, there was some technology, but every boat and most housesare made of wood (little concrete, no metal, except for the roof) and there were no electricity or hand phone (it arrived since) No car or motorbike as the village are to small and are connected by the sea, not by roads. See recent photo below No much tourist or visitor from mainland either. The obvious technology in this exact place would be * motors (no sail boat anymore) * Plastic (as wrapping, cool-box or fuel barrel) * printed cloth * glasses * metallic roof There is also a dead giveaway : ice (for the fishes). But the village I've been in was importing about one ton each day, at 8am from a bigger village, quickly pack the ice and fish in the cool boxes then ship it a soon as possible. So you can not notice this for a while. [](https://i.stack.imgur.com/mqi2i.jpg) [](https://i.stack.imgur.com/f5Tkk.jpg) [Answer] Hudson Bay. Very low population density. Few overhead flights. slow and difficult terrain to traverse. [Answer] If you really want to be on the safe side, and places like the poles, deep forests and caves are ruled out, then I'd say **that it's impossible.** Because if we assume that you can neither know nor control the weather, then if that traveler is paying close attention to its surroundings then the ISS or one of the many visible satellites will give it away pretty soon. Coming from a place and time roughly like our 14th century, that traveler (being a traveler... and probably with some naval experiences) will surely know that it's possible to use stars to determine one's location. Moving stars is surely nothing that's easily done with magic. [Answer] You said "not Amazon" but I am guessing you were assuming it would take too long to find modernity. I spent a week about two hours upstream by boat from Mazan, Peru. An occasional boat went by, but if your traveler had landed near us and followed the bank to Mazan it could take him quite some time to get to Mazan. Along the way, he would encounter five to ten houses with no electricity and maybe one or two with solar power. Water is rain water or river water run through filters. [Answer] # [Yosemite](https://www.nationalparks.org/explore-parks/yosemite-national-park?gclid=Cj0KCQjwh6XmBRDRARIsAKNInDGQaf2QKexicWS0kvxzTdOUyKDOhiQYfbKxQTnS5ShR5gm6UPNLn5IaAkMMEALw_wcB) Or some other large outdoor recreational area that limits vehicle traffic. [](https://i.stack.imgur.com/DZxZ5.jpg) The buildings and surrounds are different but still wood and stone, with no skyscrapers. [](https://i.stack.imgur.com/jrlxH.jpg) There are trails for walking and some basic roads. Nothing too techy. [](https://i.stack.imgur.com/B4jlq.jpg) There are electric lights, voices louder than than they ought to be (loudspeakers), odd ringing noises (phones), and some magical horseless carriages. People are dressed strangely and sometimes consult magical orbs in their packs. Most people who stay overnight are in tents or cabins. Others are at the Lodge. While there are toilets and running water indoors for handwashing and bathing, it's not inconceivable that another culture (plus some magic) could create these things. After all [the Roman Empire had running water](https://en.wikipedia.org/wiki/Roman_aqueduct). Please note that am including more modern tells than most of the other posters because I think it will work. Someone exposed to magic might think teleportation is possible. Then, experiencing it, will figure out that's what happened. **Time travel was not something in the popular culture in medieval times and the traveler almost certainly wouldn't even consider it.** Every oddness the traveler encounters would register as different place. It is completely normal for different cultures to vary in technology and there was enough travel and storytelling in medieval times that people would generally know this. Even fantastic beasts were known of. **A week to figure out that this is a different *time* not just a different *place* sounds about right. Particularly as the visitor gets to know the contemporaries. Even more so after they discover a tourist that speaks their European language (or some approximation of it).** ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Closed 7 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/64708/edit) A Simple scenario; you have a guy with a gun (a very big and loud gun), and a ticking nuke with seconds left. All the controls, buttons, and wiring on the thing are in a different language, and he’s just as likely to push the “explode now” button as the “stop explode” button. So he decides to shoot the thing in an attempt to disarm it. * The bomb itself is sitting in the open, not armored, moving, or hidden. * The bomb is based on real world or near-near future technology. * The guy is armed with an [anti-material rifle](https://en.wikipedia.org/wiki/Anti-materiel_rifle) and a handful of rounds for it. * Assume very high penetration ability of the munitions, but not magical ability. * The guy has no real knowledge of the specifics of how this bomb works besides “the dangerous part is probably in the middle.” The main question; **is it feasible (/likely) that shooting a nuclear bomb with a high powered man portable rifle actually disarms the thing?** (would this be taught as a last chance desperation maneuver, or taught as a never-ever-do-regardless of it going off anyways thing.) Secondarily would this just be a partial disarm, resulting in a smaller boom? Or would something like just a detonator going off and spreading radioactive material everywhere out the new ventilation holes? [Answer] **It depends.** Are we talking about a bomb built by a foreign state, or a bomb built by futuristic terrorists in a basement? If it's the terrorists, anything is possible, because lord knows how they built it. In that case it's probably a dirty bomb, and anything you do to it will turn it into a dirty bomb, so the best you'll accomplish with your stunt is doing the job for them **If it's a large nation-state built bomb, however, shooting the bomb will, at worst, do nothing and maybe leak a little radiation, and at best, disable the bomb.** I'll let you decide what exactly happens in this case. I know you said that the markings on the bomb are in another language, but I'm going to assume they stole the designs from the USA, or at least have followed a development progress similar to the USA, in order to give you references on where we stand now with our nuclear arsenal. **We no longer use touchy explosives.** The explosives used in modern nuclear weapons are some of the most stable explosives which can still be considered explosive, due to the [1968 Thule Air Base B-52 Crash](https://en.wikipedia.org/wiki/1968_Thule_Air_Base_B-52_crash#Weapon_safety). In that crash, one of the nuclear bombs being carried had a partial detonation, due to a fire destroying the controls and activating the explosive during an airplane crash. It became a dirty bomb, spitting crap all over the place. Cleanup was somewhat successful, but the biggest thing we got out of it was less sensitive explosives and fire-proof electronics boxes. **We no longer use touchy control electronics.** “Until my death I will never forget hearing my sergeant say, 'Lieutenant, we found the arm/safe switch.' And I said, 'Great.' He said, 'Not great. It’s on arm.'” ([1961 Goldsboro B-52 Crash](https://en.wikipedia.org/wiki/1961_Goldsboro_B-52_crash)). Two nuclear weapons on this plane crash nearly blew up. The first bomb completed it's arming sequence, but failed to explode because a single safety switch was switched off. The second nuclear weapon carried in this plane had also partially armed... but this one's switch was ON! The only reason it didn't go boom was because it hit the ground so hard it disintegrated before it could completely arm itself. **Our nuclear weapons are specifically designed to not work at all.** "Bypassing a PAL should be, as one weapons designer graphically put it, about as complex as performing a tonsillectomy while entering the patient from the wrong end." [Permissive Action Links](https://en.wikipedia.org/wiki/Permissive_Action_Link). After all the close calls and near misses, President Kennedy put the kibosh on the slapdash weapons we had lying around. PAL refers to the arming and triggering systems used in a modern nuclear warhead; it requires encrypted arming codes, has intentional "weak links" in the system designed to fail safe in anything but an intentional detonation... it's designed to fail except when a very specific sequence of actions are intentionally taken. Note that that complexity is involved in making it EXPLODE. It's very easy to make it not work with a PAL. I doubt shooting the bomb is considered an intentional activity. Ensuring that nukes don't accidentally explode was so important that the USA gave the tech to the Soviet Union. They developed their own system, but used the American system as a template. Ironically, the Nuclear Nonproliferation Treaty made it illegal for the USA to provide any guidance on how to safe weapons, an therefore they had to use a dodge to help France build their own PALs. China asked for data on PALs, but President Clinton said no, both for legal and security reasons (but I'm sure the security reasons could have been dodged). Pakistan refused to use USA PALs that were offered, because they fear a Kill Switch, but the NNT means we can't help them build a system they trust. In the case of China, though, I'd expect even more paranoid bombs to ensure that only a central command order could launch and explode them; Pakistani bombs are likely proofed similarly to the USA, except without the full PAL style system. In short, as another answer said, **nuclear bombs are built to fail except in very specific circumstances.** A bomb labelled in a foreign language would likely be the same, and if I was holding a rifle next to a bomb about to go off, and the only choices were to wait and explode or shoot and maybe explode, I'd take the chance. [Answer] Generally speaking, punching a hole in the side of a nuke is pretty much guaranteed to stop it functioning as a nuke. Anything which upsets the symmetry of the explosive detonation will cause a "weak spot" which will allow the developing explosion to squirt out and squib the blast. Of course, this is what is referred to as a "dirty bomb" when talking about terrorists these days. All conventional explosives can be assumed to detonate, and the resulting blast will distribute radioactive material around the area. If you're really unlucky, a gun-type uranium bomb might still function at a much lower yield, but this is still better than letting the damned thing go off at full power. [Answer] Unlike your average TV bomb, nuclear weapons in general are very carefully designed **not** to explode. They are very unlikely to have an explode now button, and much more likely to feature a very large well labeled (possibly in several languages) stop button, something like your standard big red stop button on most industrial machinery. Arming and detonating them tends to be a very complicated process involving multiple keys, codes or other complex arming mechanisms, not likely to be accidently done. If however you found some cobbled together poorly labeled DIY nuclear explosive a few shots from a gun could possibly disable it or more likely misalign things sufficient to keep it from causing a full nuclear explosion. It would still be quite likely to explode from all the conventional explosive contained in the device which are used to smash the fissile materials together. I'm not an expert on conventional explosive devices but I would generally advise against shooting them. So your hero might save the city from nuclear destruction, but he is likely do die from the conventional explosion and the general area will probably be a government cleanup site from all the spread of the nuclear material. [Answer] So nukes are pretty complicated, and kind of depend on things happening exactly right. Implosion nukes (most modern nukes) have a pit of material surrounded by shaped charges. These charges are positioned so that they push a majority of the force inward toward the pit, and so compress it down to critical mass. In order to get all the charges to go off at EXACTLY the same time, they will do things like make sure that all the wires hooking up the charges are the same length, so that the speed of light isn't a factor. If the near side of the charge goes off a millisecond before the far side because the electrons had a shorter path, you could get a fizzle instead of a boom. So if you shoot the nuke, it is likely that you'll disrupt the blast pattern, and could cause the explosion to be off center. This would keep it from going supercritical, but there is a chance for nuclear material to be spread out as a kind of dirty bomb. Also it's still several pounds of explosives, so anyone standing close is going to be in danger. [Answer] ## Shoot the control box Nukes are touchy things that have to be very carefully timed and manufactured to go off properly. Destroying the control box removes all the timing gear that will make the bomb go off. ## Fat Man style bomb A look at the [Fat Man bomb](https://en.wikipedia.org/wiki/Fat_Man) shows that shooting the main part of the bomb won't do much to stop bomb from exploding. I don't know what the tolerances are for distorted/misplaced explosives but this guy won't save himself by shooting the explody parts. ## Little Boy style bomb Since the [Little Boy bomb](https://en.wikipedia.org/wiki/Little_Boy) relied on shooting a projectile down the center of the bomb into a uranium target, disrupting the firing tube may prevent the bomb from going off. ## Always aim for the control box The best way to stop a nuke from going off is to make sure it never gets the signal to detonate in the first place. **Shoot the control box.** [Answer] You can also look at it in a different way. Nuclear bombs are designed to be as powerfull as possible. Shooting it will make it either less powerful, or will change nothing at all. You won't make it worse by shooting at it. [Answer] While the other answers are correct that anything which disrupts the symmetry of the initiating explosion might be sufficient to cause a fizzle or engage one of the multitude of safety devices which prevents nuclear weapons from detonating during transit or in flight, this might need to be caveated somewhat. Thermonuclear weapons (H-Bombs) have a fission device which is the first stage to irradiate and initiate the fusion fuel for the much more powerful second stage. In order to contain the vast energy output of the trigger for the critical microseconds, a "tamper" made of depleted uranium is often used as the casing of the weapon. Since Uranium is quite dense, it is also used as armour for main battle tanks (such as the M1 Abrams). For you, this means your anti material rifle will need to be one of the larger ones available (using a .50 BMG round is probably the minimum), and you will have to ensure you use AP ammunition to penetrate the casing and cause damage within. You will also need some detailed knowledge of the layout of the device, so your round penetrates the casing and hits the fission trigger, otherwise you plow a hole though the Lithium deuteride fusion fuel. [](https://i.stack.imgur.com/xkZ1i.jpg) *A 25mm Barrett XM-109 should do the trick* Of course, you could simplify matters by simply hammering the thing with an actual .50 HMG, and put enough holes in it that statistically you will damage some critical component, but that is hardly elegant. [Answer] Probably worth considering that nuclear bombs are (often) designed to hang off the outside of a high-speed jet aircraft, fall several thousand metres and either smash into the ground or through the surface of the water *before* exploding. If you do smash the *inside* of a modern weapon then one of more of the fail-safes will almost certainly prevent its detonation. If it's an older weapon then you might succeed in only damaging the precise implosion device, turning it into a dirty bomb instead of a full-on nuclear weapon - probably still bad news for your protagonist and everyone nearby, but much *less* bad than a full nuclear detonation. The chance of actually setting it off with a rifle shot is basically zero - high explosives are very insensitive (due to the conditions described above) and the impact of a shot would do nothing. You can even set them on fire without a bang - US soldiers in Vietnam would sometimes use HE as a cooking fuel. But there is a chance that even with a high-powered rifle that all of that might not work if it's still in the casing, and the richochet could well kill or seriously injure your hero. Probably better to unbolt the thing and then start pulling bits off or cutting wires inside. [Answer] It comes down to where he shoots and how the weapon is designed. If he can see the explosive core and shoots it it is no longer a nuclear bomb. It's hard to imagine a core that can still function correctly after taking a bullet. The whole point of all the complex engineering of the bomb is to perfectly symmetrically crush the core. What do you think will happen if you fire bullets into any reasonably soft piece of precision engineering?? If the bullet hits a detonator the result very well might set off the detonator and the shooter dies (but he dies anyway when the timer runs down) but again it's not a nuclear bomb. Now, if his target choice is bad we have some different options If the bullet tears through the electronics he may block the detonation signal, he may block the timer, he may block the proper distribution of the detonation signal (resulting in merely a conventional explosion) or he may set it off (full nuclear yield.) Finally, if he shoots it's power source it depends on how it's built and how much residual power might exist in capacitors. If the weapon was designed to salvage fuse it goes off (full yield), otherwise it depends on whether the capacitors still have enough charge when the timer runs to zero. Note that in all cases "conventional explosion" means the plutonium core is scattered about to some degree. I would not want to enter the area for a while without breathing gear or a very good dust mask but it's nowhere near as nasty as a dirty bomb. If the emergency crews know it's a failed nuke there should be no radiation casualties. My personal choice would be to put my first round into the core, upon seeing that it was torn up I would then aim for power sources--a single large capacitor if I saw one (my understanding of modern military weapons is that they are set off by dumping a very high current through a wire, this is more complex than a traditional blasting cap but basically immune to being set off by shock. Kill the capacitor and it's not going off), otherwise batteries. While you only specified one type of weapon the same basic reasoning applies to most any weapon the police or military might carry. Things with enough boom would no doubt cause a conventional detonation. The only things that wouldn't be of use are the subdual weapons police carry (taser, mace etc.) Hollywood almost always gets this very wrong, the only way the bad guys can ensure the bomb can't be defused by smashing it is by denying access to the bomb with something that will set it off **very** quickly if breached. This will make for a pretty big package as you have to set it off before the jet of a large shaped charge can destroy the core--and said jet is moving at NASA-type velocity. [Answer] Shooting at a nuclear weapon with a gun is unlikely to achieve anything much. A fission bomb works by using conventional explosives to compress the fissile material enough to allow the chain reaction to start. A fusion bomb works by using a fission bomb to compress the fusion core enough to allow its chain reaction to start. The first of these things requires a case strong enough to contain the conventional explosion so that the effect is to compress the fission core, rather than just blow the weapon apart. The second of them requires a case strong enough to contain the fission explosion for long enough to get the fusion reaction going, rather than just blowing the weapon apart. Both of these things require a case that's strong enough that it shouldn't care much about being shot at. Also, why would there be an "explode now" button or a "don't explode now" button? It's hard to imagine why the first one would ever be used, and the second one sounds like a great way to have your bomb fail to detonate if it happens to hit the ground the wrong way. [Answer] It *could* work. It could go off. It could make no difference. Since we don't really know the specifications of the bomb, it's not possible to say with any authority. Personally, I'd say press a button at random; far better odds if this is all the information you have. Unless of course, this bomb's in Hollywood--then run around like a headless chicken till the timer says less than 10 seconds left. Then shoot. ]

[Question] [ Not sure if this still falls under worldbuilding. Let's assume a civilization living with the following restrictions: * No access to the surface or ability to observe it (no sky, no atmospheric samples from the surface, no distant large objects, etc) * No means to see distant objects in a straight line (caves and tunnels will limit visible range)\* * Almost all light sources are artificial * No knowledge about how deep underneath the surface they are (unless this can be deduced by the available information below). * No electricity or computers * No magical means to gather information \**technically, they could try and build these things through heavy terraforming.* But here are things they can check or do know: * Advanced knowledge (whatever is needed; math, physics, chemistry, etc) * The gravitational constant * Temperature, pressure, atmosphere * Density of surrounding rock and material * Natural features like underground rivers, lakes, lava, and so on. * Limited ability to change elevation through cave systems (1-2km perhaps? How much would be necessary, if this helps at all?) Essentially, it boils down to this: Can you deduce the shape & size of the planet you are on, by logic and with the gravitational constant while locked in a confined space with no outside view? Bonus: Do they need to know that a "surface" exists (that they are underground), to deduce this? If they don't know about any surface (or that concept), would they deduce it's existence during this process? The key question is, if they **can**; not necessarily *how*. But that would be really interesting to read. **Edit:** Any connections to the surface exist as needed to allow for the environment to exist (air, water), but if they do they are just unreachable and not known of. Even if they would happen to follow a stream of water, it would ultimately just come from a hole in some rock wall. I'm primarily interested in deducing information in such a limited framework, not in how to break the rules and change the framework itself (for example, by digging up to the surface), or how the framework can exist. [Answer] # Trivially (It's not a complex problem, and they have access to sufficient information) # but not easily (they need to do some serious engineering projects to get the data.) Steps 1. conceptually figure out they are on a spherical planet, or at least know that this configuration is one possibility. 2. Dig a horizontal tunnel. Horizontal as measured by plumb bob and/or spirit level. Observe the curvature of the tunnel relative to a light in the distance. Do the same with a tunnel at right angles to this first, to determine that the curvature forms a sphere, not a cylinder. This and some simple math gives them the exact curvature of the gravity over the length of the tunnel, thus gives them an exact distance to the core of their planet. **At this point they know they are on a spherical planet, and exactly how big is it up to their tunnel's level.** 3. Build a large tunnel network at this same level. Specifically, dig the tunnels at various angles such that they have a grid of location, at the same level, scattered over a geographically large part of the planet. At least several hundred km, if their planet is Earth-sized. We need a number of locations at the same gravitational altitude, but with various latitude/longitude combinations. 4. Install a [Foucalt's Pendulum](https://en.wikipedia.org/wiki/Foucault_pendulum) at many locations in the tunnel network. The closer the pendulum is to the equator of the revolving planet, the slower it will rotate its apparent axis. *On* the equator it will just swing as released, not turning. At the pole it will rotate exactly once per day. If the tunnel network does not cross the equator of pole one can still get the exact latitude, but you have to beat your data with a very thick maths tome to get it to confess the answer. **At this time they know how large their planet is, from core to their tunnel. They know its shape. They know that it is rotating, and they know exactly how long a 360 degree rotation takes. They know exactly where they are located on the planet, both in latitude (calculated) and longitude(relative to some arbitrarily selected line)** I know of no way for them to determine how deep they are. They might get *some* indication from echosounding, but a soil surface *sucks* at returning a sound wave that hits it from below. You are much more likely to detect rock type boundaries, water table, metamorphic transitions, etc... Maybe they could use the increase in temperature as you go down, coupled with the concept of absolute zero temperature, to put an upper limit to the distance from their tunnels to the surface? [Answer] As an underground civilization, we can assume that they have an elaborate system of seismographs. It helps, after all, to know when the ceiling is about to come down on your head. With knowledge about densitities of material and knowledge of physics, calculating the speed by which an Earthquake propagates through rock ought to be feasible. Armed with this knowledge, and with a sufficiently sensitive seismograph, they can gather a lot of useful info. For example, they can detect how deep they are because Earthquakes reflect of the surface. And, if they have really good seismographs, they might be able to detect the echo as the quake goes round the world, allowing them to figure out both it's size and that is roughly spherical (as the echo appears to converge onto the epicenter, instead of bouncing of a flat surface). [Answer] What they can do is start digging a tunnel in a straight direction, and shine a powerful light through it. How can they check that they are going straight? The always dig orthogonally to the direction defined by a line with a weight. At a certain point the tunnel, following the curvature of the planet, will deviate from the straight line path of the light. If they assume$^\*$ the planet is a sphere, by measuring the distance at which this happens and with some [basic trigonometry](https://en.wikipedia.org/wiki/Horizon#Distance_to_the_horizon) can deduce the radius of the planet. $d =\sqrt{h(2R+h)}$ [](https://i.stack.imgur.com/YSKSK.png) Why would they do this is another story. Maybe they want to build a fast road, and a straight path seems to be the most efficient way, and a certain moment they notice they can't see all the light at the end of it. $^\*$ The assumption can be done after noticing that the phenomenon happens in every direction they pick for digging the tunnel. [Answer] **No, but...** Thanks to the [Foucault pendulum](https://en.wikipedia.org/wiki/Foucault_pendulum), an invention from the eponym French genius (XIX century), your civilization can follow this reasonning : 1. The planet is spherical and it turns on itself around an axis. 2. They can find the poles by searching the point where the angular velocity is maximum. They can also find the equator (where the angular velocity is null). By the way they can also find the pole with a compass. 3. With some trigonometry they can calculate the radius of the sphere beneath their feet. However it is not possible to determine the radius of the planet which includes the part above them. You can achieve the same result with a compass but it is less practical as it you need to have straight lines along very long axis following a lattitude parrallel. Interresting fact : If they find a Pole they can determine the length of a day (the duration of one revolution of the pendulum) [Answer] # Limits The theoretical maximum amount of rock that can be over a natural cave is 3,000 m (per <https://en.wikipedia.org/wiki/Cave> which gives no obvious cite). This matches well to the crushing pressure of rocks, though. Beyond that, even the hardest stone will be crushed down by the rock above it, to fill the void. No caves have been found this deep. The deepest oil wells are deeper, though, up to 9.5 km. The deepest hole ever drilled was about 12 km, and the temperature at the bottom was above boiling point, so would not have supported life. The deepest mine, and the deepest a human has ever gone, is 3.9 km. On a planet with lower gravity, or in a species which lives underwater (so the pressure between rock and water is equalized and the caves don't crush so easily), far deeper caves would be possible. So it seems there are answers already aplenty to establish what's below, and their position relative to it: * how fast their rocky universe rotates about an axis (Faucalt pendulum). * what angle they are to the axis (pendulum rotation = universe rotation rate x sine of latitude) * how far they are from the gravitational core (curvature of level tunnels, divergence of parallel vertical tunnels, etc) Finding the distance to the surface is arguably a trickier proposition, but there have been many ways proposed for indirect measurements. * The pull of the mass above you. But inside a sphere, there is no net "pull of the mass above you", so gravitational measurements of the rock above you are not going to help. * Echo-sounding/seismographic surveys. On most planetary-sized objects, this would definitely work no matter how deep they are, at least with seismic/nuclear-level waves. Nukes are unlikely to be popular as scientific measurement tools for civilizations living underground, so only seismic effects would give a big enough wave to measure as it reflected around the world. * Rock type boundaries/Metamorphic transitions. This one is interesting, it requires understanding of rock formation and subduction, but could work as way to double-check other results. * Water table. Requires them to *have* a water table, mind, and I'm not sure this is a reliable estimate of depth from surface. * Geothermal gradients. * Air pressure, to get atmospheric height. * Digging upwards. * Liquid pressure measurement in a chamber. This would work, but is unnecessary: an important measure when mining is the pressure of the rock, and for this you can measure the deformation of a drilled hole using common mining equipment. An underground civilization would likely have improved over our own approaches for this. <https://geoinfo.nmt.edu/publications/monographs/circulars/downloads/69/Circular-69.pdf> explains the basics (at least as they were in 1963: I imagine we use much more sensitive electronic measures now) ## Can we make a planet which makes this maximally difficult? Really, the most interesting questions (from a world-building perspective) are whether it's possible to make this *really hard* for the inhabitants; and how deep they could be living before pressure from the rock made living impossible. We could have a rogue planet, cast off from its sun (perhaps by a near-miss with another planet, perhaps by the ancestors of its current inhabitants). They have dug deeper and deeper as the core cooled. The atmosphere and oceans have been ripped away, If they did dig up to the surface, they'd be dealing with the extreme cold (~3 Kelvin) and hard vacuum of deep space. So they avoid digging upwards. They might have legends of sealing their caves from any fissures that did open, but they come from countless generations back: they are too deep now, 10s of km below the light planet's surface. The planet is either not spinning significantly, or is tumbling slowly and chaotically enough that pendulums don't help (tangential question: is it possible to make a tumble chaotic enough that you could not factorize it to pitch/roll/yaw with pendulums?) Losses of knowledge over deep time (plagues, wars, natural disasters) mean that they don't have nuclear weaponry or power, nor can they perform terraforming-scale efforts. For whatever reason, their records of core temperature measurements go back at most just a few generations, so they can't use the speed of cooling of the core to calculate the insulating thickness of rock above. (tangential question: How cool would it have to get before there were no longer quakes, and how deep would people have to have dug? Could heat from radioactive material help reduce this? Even the moon has moon-quakes) Being a rogue planet, asteroid impacts would be too rare to use as stand-ins for seismic effects. Assuming they don't live in water, their max depth is determined by gravitational strength acting on the rocks above them. On a light planet, like the moon, that could be tens of km. ## Could even this deliberately-limited civilization figure it out, then? Well, divergence of vertical shafts would still give their distance from the center of planetary mass. So they would know their rock universe *had* a center of mass. They would be able to measure pressure gradients in the rock, and know the mass of rock, so if they assume similar rock all the way above them, can calculate the depth of rock above them. If they assume a spherical planet, that gives them a planetary radius. Reflection and absorption of seismic waves would tell them the varying densities of rock on the planet, letting them make the calculations about gravity more precise. But they can compare that to the gravitational constant to determine that a spherical mass of rock to generate those readings is consistent with the gravitational strength they measure. And they can use what they know of rock's crush-strength and gravity to calculate the potato radius ( <https://www.technologyreview.com/2010/04/12/27697/potato-radius-to-define-dwarf-planets/> ), to prove that the planet is spherical. [Answer] Others have covered measuring the size and shape of the habitable level. The distance to the surface may be estimated as follows: 1. Dig a chamber in the rock. 2. Place a sensitive distance measuring device between the floor and ceiling of the chamber. 3. Widen the chamber. Since the ceiling now has less support, it will sag, and your measuring device will register this fact. 4. Seal up the chamber. Pump fluid in until the ceiling height has returned to its original value. Measure the fluid pressure. In the limit where you start with a narrow chamber and measure a wide one, the pressure of your fluid is simply the weight of the rock above per unit surface area. Since it is assumed you know the gravity and the density of rock, you may thus calculate the distance to the surface. [Answer] To actually have it occur to these underground people that they live inside a layer of a sphere would take some remarkable insight. Humans began realising this looking at far away things, and got further inspired by looking into the sky (where there are even more distant things!) IF someone gets the idea though, it's very possible to verify. I can think of two ways to do this on a reasonably small scale. Find a large underground lake, or construct a long straight tunnel and cover the floor in water. If you lay on the floor at one end, you will find a horizon less than a kilometre away. If you can construct a telescope you could make quite precise measurements, quite possibly more precise than at the surface if you can avoid the wind making waves! Then use the formula in @L.Dutch 's answer. If you don't have optical instruments or for some other reason find the above approach unsuitable: Find a large cave. The larger the better, but about 250 m high and 1000 might be a minimum requirement. Find some good rope and make a rectangle 250 m by 1000 m, and hang it in the cave such that the sides are vertical. On earth, such an experiment will show that the bottom line will slack more than the top one no matter how you turn your loop, as the difference in length at the top and at the bottom will be a few centimetres. (See the calculation for a bridge [here](https://www.mathscinotes.com/2017/01/effect-of-earths-curvature-on-suspension-bridge-dimensions/)) This would of course be carried out several times, and it requires really precise measurements. Depending on what materials your people have access to one of the approaches might be more feasible than the other. Now we know how large the world is **at our height**! How much world is above us? I'm afraid this is much trickier. IF the atmosphere in our caves is connected to the outside, we could measure the air pressure at various altitudes (... negative altitudes?), and then extrapolate to find *the height of the atmosphere*, but I don't have any good ideas for how to find the amount of rock above you except for the obvious one: **Dig your way upwards!** --- Bonus answer, if you're on a (very) small planet: One experiment which is marginally easier than to **simply go around the world** is to make a large triangle. An equilateral triangle in a plane will have all angles equal 60°, but an equilateral triangle drawn on a sphere will have larger angles. Using the spherical law of cosines (<https://en.wikipedia.org/wiki/Spherical_trigonometry>) one finds the angle $A$ of a spherical equilateral triangle with side $s$ equals $$ A = \arccos \left( \frac{\cos x - \cos^2 x}{\sin^2 x} \right) $$ where $x = \frac{\text{Triangle side length}}{\text{Planet diameter}}$. This might actually work on a small planet or moon. On earth, an equilateral triangle with side length 2 000 km has angles of about 61°, so don't try this at home. [Answer] Once you know that your planet is spherical and have calculated it's size using observational trigonometry as outlined in the other answers you can calculate the approximate size of the world and thus your depth with a little physics. Gravity at a depth below the surface varies due to less mass below you and the pull of the mass above you. A related Physics SE question relates <https://physics.stackexchange.com/questions/18446/how-does-gravity-work-underground> If they have the ability to measure the local gravity at different depths to great enough precision they could calculate the mass of the planet and it's radius at the surface. Density variations would give some variability, but it would give a first approximation and could be refined based on increased geological knowledge of their planets interior. EDIT: To clarify how this works, a rough equation for gravity at depth d is: g(d)= G x M x (R−d)/R^3 Where G is the gravitational contant, M is the mass of the planet, and R is the radius of the planet. If G and M are known and gravity can be measured directly at 2 depths a known distance apart you could solve the two equations for both the radius of the planet and the corresponding depth of one of the gravity measurements. [Answer] Foucault pendulum was already mentioned. 3 more ways to detect rotation of the planet with simple devices, taken from MOTION MOUNTAIN by Schiller. In 1913, Arthur Compton showed that a closed tube filled with water and some small floating particles (or bubbles) can be used to show the rotation of the Earth. The device is called a Compton tube or Compton wheel. Compton showed that when a horizontal tube filled with water is rotated by 180°, something happens that allows one to prove that the Earth rotates. The experiment, shown in Figure 104, even allows measuring the latitude of the point where the experiment is made. [](https://i.stack.imgur.com/2x6b9.png) In 1910, John Hagen published the results of another experiment. Two masses are put on a horizontal bar that can turn around a vertical axis, a so-called isotomeograph. Its total mass was 260 kg. If the two masses are slowly moved towards the support, as shown in Figure 103, and if the friction is kept low enough, the bar rotates. Obviously, this would not happen if the Earth were not rotating. Hans Bucka developed the simplest experiment so far to show the rotation of the Earth. A metal rod allows anybody to detect the rotation of the Earth after only a few seconds of observation, using the set-up of Figure 106. The experiment can be easily be performed in class. Can you guess how it works? [](https://i.stack.imgur.com/21WuV.png) A usable gyrocompass was invented in 1906 in Germany by Hermann Anschütz-Kaempfe, and after successful tests in 1908 became widely used in the German Imperial Navy. [Answer] ## It Would Be Difficult to Prove One situation where I don’t see how is if they start in the center of the planet. The gravity on all sides cancels out, so they're weightless and a plumb line won’t lead anywhere. Therefore, none of the answers that say they’ll follow a plumb line will work. Digging up in any direction will reveal that gravity is a force that pulls them back to the center of the universe, and gets stronger the further away they dig. If the planet is rotating, they can measure that too, and see it gets stronger the further away they get. But the obvious, intuitive explanation for this is that they live in a cosmos of solid rock around their home in the center of the universe. ## But Maybe They Could They could in theory dig all the way up to the surface, or the impenetrable crust, but you say these people do not have that ability. They can figure out that gravity and the rotation of the universe can’t get infinitely strong, so someone probably does theorize that there’s some distance where the forces on rock must pulverize it, and, in theory, the rock within that radius would form a sphere of solid rock covered in dust. They know the rate at which gravity increases and the amount of force it takes to crush the kind of rock they've been digging through. You say they can know the gravitational constant. They can precisely measure the gravitational pull of things like dense mineral deposits versus pockets of gas. It's at least possible someone might come up with the hypothesis that gravity is caused by there being more mass below them than above them, and realize that this matches the gravitational pull (and rotation, if they are within a rotating planet) of digging up through a sphere of uniform density. This would let them estimate the radius of a sphere of uniform density required to explain the change in gravity, although they have no way to know if the rock gets denser or less dense higher up without digging through it. It would be difficult to rule out other hypotheses, but @10ebbor10 suggested they could detect the reflections of seismic waves from the surface. Modeling their world as a sphere of uniform density, and knowing the density of rock and the gravitational constant, they can calculate the gravitational pull of the mass beneath a point a certain distance from the center and subtract the gravitational pull of the mass above with a bit of integration in cylindrical coordinates. Because of symmetry, all lateral forces would cancel out. Measurements of the force of gravity at different heights would then let them solve for the radius of the sphere. ]

[Question] [ Is there an order in which different kinds of (unshielded) electric devices go out in the event of a high altitude EMP? For example, first small gadgets, then electric vehicles, then grids. Or do all unshielded devices go out pretty much at the same time, seemingly instantaneously, with no specific order or delays depending on the type of device? [Answer] Last summer, a lightning bolt struck a tree right outside my apartment building (so close that I hit the floor). As you may be aware, [lightning creates a small EMP blast](https://en.wikipedia.org/wiki/Lightning#Transient_currents_during_flash). The power went out momentarily and when it came back on, my desktop PC would not boot and my TV no longer had sound (yes, everything was plugged in to a very nice [APC UPS](http://rads.stackoverflow.com/amzn/click/B004F09CVO)). The PC turned out to be a fried motherboard. A week or so later I noticed that my Wi-Fi was flaky. It was constantly dropping connections. That could be unrelated, but I threw it on the insurance claim as well. I wasn't the only one affected. My upstairs neighbor swears he saw a small ball of lightning in his bedroom, and he lost his TV, cable box, and cable modem. Another neighbor lost the DSL modem and a TV as well, but the worst (IMO) was the car that was parked directly under the tree. I don't know what fried on it, but it wouldn't start after that and had to be towed to a mechanic. So to actually answer your question; anything that is going to be affected is immediately affected (well, immediately as in tens of microseconds). However, a device may *sort of* function after it's been affected and it may take a while to notice that it has failed (like my Wi-Fi router). So, an example might be a radio that is no longer able to receive but can still transmit, or maybe that radio can only send/receive on certain wavelengths. If you had several circuits carrying current to a device, and only some of those circuits were blown out by the EMP blast, the remaining circuits *could* fail if the device they were powering drew too much current for the remaining circuits to handle. I can't speak for military or "hardened" devices, but I know consumer and professional electronics just aren't designed that way. In a consumer device, there is one power circuit, and if it doesn't go in the EMP pulse, it's 100% fine afterwards. In a commercial device (like the APC switchable UPS's I use at work), there are redundant power supplies. If one goes, the other is designed to handle 100% of the load. Designing something to only work if both PSU's are running would be silly (because it would be less dependable, not more). [Answer] All direct effects happen at practically the same time (light speed from the EMP source still apply). That said, if you will burn longer tracks on PCB, tracks in complicated devices would get burnt immediately - because these are thin and delicate. On the other hand, tracks on PCB in an old car might get only some damage, and electronic connected to them might be hardy enough not to fail immediately. In such case, a damaged diode or track might function correctly for some time, it's condition worsening with use, until complete fail. [Answer] EMPs work by creating rapidly changing electrical and magnetic fields. When these come into contact with electronics they induce a power surge that may fry electrical components. All modern electronics have weak/sensitive components that will fry instantly. EMPs are also quick so if an electronic component doesn't instantly fry from it then it will most likely keep working, unless it is badly damaged and over a few seconds it keeps getting worse until it dies out. ***Note:*** Weaker EMPs may simply force devices to restart since they won't fry the components but simply mess with the bits making the device run into a "Blue Screen of Death" or similar. ***Edit:*** Since Tim added some real life experience I thought I could add some experiences I've had with lightning One day when I was walking back home while listening to music a lightning hit kinda close and I heard some interference before finally hearing the thunder. I guess the current induced by the EMP wasn't strong enough to fry anything but only to create interference in the wires. I've also had experience with lightning affecting devices connected to the grid. The first time this happened my TV got fried and after that I got a UPS. Now that I have a UPS whenever a lightning strikes, my UPS just shuts off, protecting my devices, and I have to restart it. The UPS has a battery so the devices can keep running with it powered off. [Answer] ## EMP won't kill everything It'll be totally hit-and-miss what gets nailed by EMP. A row of police cars, all same make/model, might all get their PCM (engine) computer killed except for one, while two more parked at a different angle might work fine except for power windows and radio. Boeing aircraft might be flyable (with the DirecTV and FMC not working) while 75% of Airbus aircraft are heavily damaged. The power companies may find many of their Eaton controls took a hit but very few of their GE's. A bunch of railroad lines, using older tech, may be totally unaffected, while the railroads are unable to control trains from their central dispatching centers and must go back to "old-school". In case you catch what I'm implying, engineering mentality and build quality matters. I expect Boeing to be thinking hard about this, since a lot of their business is warplanes or military derivative of commercial airframes, like Air Force One and other VIPs, P-8 Poseidon, KC-767, etc. Eaton vs GE, no idea, it's just a made-up example. You just don't know until you pop a nuke over one, and you're not going to do that, unless you take a serious disliking to the Test Ban Treaty. [Answer] An Electromagnetic Pulse is a brief magnetic field. When electrically conductive materials (like wires) pass through a magnetic field it causes electricity to flow through the materials. This is how a generator creates electricity. In an EMP attack the idea is to create a very strong magnetic field that causes electricity to flow in wires and circuitry. The attacker is hoping to cause enough power to flow to burn out components. It doesn't matter if the device is plugged in or not, though long wires like power lines can build up more of a power surge if they are lined up right with the magnetic field, which can send a surge through an outlet. Magnetic fields travel at the speed of light, so from an observer's perspective it will appear to affect everything at the same time. Devices won't go down at the same time though, it will depend on how well they handle the pulse. If they're magnetically shielded the pulse might not be strong enough to affect it, or the pulse won't create enough power flow in some devices to hurt it. A weaker pulse can just cause the device to crash or reset. [Answer] If what you have is a single, strong pulse, then the timing differences are going to be based on physical distance from the source and the propagation of the wave. Since the wave travels at pretty near the speed of light, for practical purposes it's instantaneous unless the distances involved are quite large. Depending on their sensitivity to EMPs and the strength of the pulse, devices might catch fire, suffer component damage, suffer transitory malfunctions, or be unaffected. Devices may be affected differently depending on whether they are running or not at the time the pulse happens. If, on the other hand, you have a series of pulses, then all of the above applies with the addition that devices that suffer only minor damage or transitory effects may have those effects stack up over time to cause actual failures. In this case, the less shielded/more susceptible devices will likely fail first, followed by incremental failure of the tougher devices as the pulses continue. How "tough" a device is can be roughly determined from three factors: How easy it is to damage the components, how much wire is oriented in such a way that it will pick up voltage as the EMP goes past, and what percentage of the EMP can reach the device (faraday cages and distance can make a big difference.) Examples: * The power grid is made of exceptionally tough components, but it has miles of wire that act like giant antennas and pick up massive amounts of induced current. One, extra-large solar flare in 1859 plus miles of wire resulted in some telegraph offices on half the globe literally catching fire. (And, apparently, some of the ones that survived being able to send messages for a while without the power supply being hooked up.) * Your phone has much less wire and won't pick up nearly so much stray power, but its components are much more delicate and it doesn't take as much to damage them. * Put your phone inside an unplugged microwave, and the faraday cage that normally keeps the microwaves in will, instead, keep the EMP out (unless it's really, really powerful, but past a certain point it becomes more death-ray than EMP) * A series of light pulses could fry the phone without causing any significant trouble to the grid. * One, big pulse tuned to probably something in the ELF frequency range could toast the power grid without the phone even noticing. (Unless it was plugged into said grid at the time, obviously.) [Answer] As the other noted, the EMP blast propagates from origin with the speed of light and its intensity decreases with a square of radius. Also, some components are more vulnereable to the overload - microprocessor on the weak part, thick copper wire on the tough side. The mode of failure matters. 1. Direct failure: The working part is the one that was EMPed. Such devices, no matter their size, comlexity or age, will fail almost immediately the shockwave hits them. Fine electronics will fail instantly, tougher ones will last fractures of a second. 2. Delayed failure: The EMPed part is a component of a more complex device. In this case the device will fail when the EMPed part is needed for the first time. Say there is really old car and EMP fried its alternator only. The car is working until it drains all the power from its battery. 3. Failure initiation: The EMP overloaded some parts and their lifetime was significantly reduce. Or the EMP killed some part that was backed up by different part which is now constantly overloaded. After some time the now-overloaded part fails. Say there is powerline divided into several parallel and insulated lines and because of the overload part of it was overheated, several wires were cut and welded together. In the wounded part the current is higher than in the untouched wires and is heating up. At some point it will break. **tl;dr:** The EMP damage front is moving with a speed of light. Before and after, no damage is dealt. The effect of the damage, on the other hand, may be dealyed with the respect to what was damaged and how serious the damage was. [Answer] For the most part EMP would fry anything solid state whether plugged in or not. For complete EMP immunity go old school technology- Vacuum Tube.. they are completely immune. > > EMP is seen as a secondary effect of all types of nuclear weapons, and was a problem in the very first nuclear weapons test in July, 1945. The official technical history for that first nuclear test in 1945 states, "We can understand the difficulty of transmitting signals during the explosion when we consider that the gamma rays from the reaction will ionize the air and other material within hundreds of yards. Fermi has calculated that the ensuing removal of the natural electrical potential gradient in the atmosphere will be equivalent to a large bolt of lightning striking that vicinity. . . . All signal lines were completely shielded, in many cases doubly shielded. In spite of this many records were lost because of spurious pickup at the time of the explosion that paralyzed the recording equipment." > > > As I stated on another page on this site, consider this Cold War era quotation from a widely-read and highly-respected publication: "The United States is frequently crossed by picture-taking Cosmos series satellites that orbit at a height of 200 to 450 kilometers above the earth. Just one of these satellites, carrying a few pounds of enriched plutonium instead of a camera, might touch off instant coast-to-coast pandemonium: the U.S. power grid going out, all electrical appliances without a separate power supply (televisions, radios, computers, traffic lights) shutting down, commercial telephone lines going dead, special military channels barely working or quickly going silent." -- from "Nuclear Pulse (III): Playing a Wild Card" by William J. Broad in Science magazine, pages 1248-1251, June 12, 1981. > > > The reason that EMP is getting more attention now is that the critical infrastructure that sustains our lives is becoming increasingly sensitive to the effects of EMP. This is happening because electronics equipment is becoming more sensitive to EMP all the time, and critical infrastructures are becoming increasingly dependent upon electronics. > > > The next myth is what I call the either-or myth with regard to electromagnetic shielding. The myth is the belief that either an electronic device is resistant to EMP or that it must be enclosed in a military-grade faraday cage. This myth is so bizarre that I heard it for years before I realized that many people actually believe it. Unfortunately, many of the "professionals" working in the EMP field seem to be responsible for spreading this myth through careless comments. > > > Of course, it is always better to have as much shielding protection as possible, and the means to obtain a high level of electromagnetic shielding are well known. The problem is that a maximally effective shield is often simply neither affordable nor practical. > > > If a device has a damage threshold of an EMP field of 20,000 volts per meter, then reducing the electromagnetic field by a factor of 3 or 4 will be enough to protect it from known weapons, and shielding it by a factor of 10 will protect it from the super-EMP weapons that are believed by many to exist. A very efficient 80 db. faraday cage would reduce the EMP by a factor of 10,000. In other words, it would reduce a 20,000 volts per meter EMP field to 2 volts per meter. This high level of shielding is necessary for some applications, but not for the average consumer (except for the most critical electronics such as an emergency radio receiver). For many applications, an imperfect shield is quite helpful and may be all that is necessary. (In some cases, though, such as an expensive solar panel system, it makes sense to try to get as close as possible to military grade protection since a functioning solar power system may determine whether you have electricity or not.) > > > and: > > When EMP (or lightning) hits the ground, the currents tend to spread out horizontally. These ground currents can do great damage, especially to underground cables of all kinds. Metal conduits are of little help, and may actually make the situation worse by providing a path for underground currents which can, in turn, induce large voltage spikes on the underground lines inside of the conduits. A large amount of damage has actually occurred due to these underground currents, due to both lightning strikes and nuclear EMP. This is one reason that so much of the information on the internet on grounding and on underground cabling is pure nonsense. Large variations in soil conductivity makes the ground current situation even more complex. > > > **Source: Jerry Emanuelson, B.S.E.E. Futurescience, LLC** [Answer] Most of the answers dance around the real issue, I think. If I break "a component" of a computer, when will the computer stop working? Well, obviously it might stop immediately, it might stop after a couple of minutes, or it might not ever fail. It depends on the component, right? So, if instead of me breaking it, it "fries" due to EMP, do you think the possible range of behaviors are any different? As said, the currents created in conductors due to an EMP are immediate and quickly over. The damage may be so severe that the circuit is then shorted or it may have damaged the circuit so that it will soon fail or the damage may be marginal so that, for example, instead of a mean time between failures of 100,000 duty cycles, it's been reduced to 1,000. Or perhaps its been damaged so that the next time it sends current to a particular device, it shorts. Keep in mind that anything which absorbs the EMP (which has to happen to do damage) will also (to some extent) shield other devices in its "shadow". Perhaps you've seen the photographs of Hiroshima, where people's silhouettes have been burned onto walls and roadways? Those same pictures show some buildings still standing when most everything else was flattened. My point here is it's neither all-or-nothing, nor is it gradual. To some extent it will be random (depending on what the device is doing at the instant it happens and where exactly it is (as well as what is around it).) Consider it to be a statistical thing. Let's say cell phones. There will be some distance inside of which everything will surely fry. Beyond that there will be distances with decreasing probability of failure (average failure rate will decrease with distance as 1/r²) until at some distance there's a low probability of damage. A very important qualification: Most nuclear weapon EMP scenarios include the interaction between the initial EMP and the Earth's ionosphere which can distribute the EMP over a very wide area. In that scenario, the damage would be literally hit and miss and hit and miss... [Answer] Capacitors could soften the blow of an EMP strike. They store extra charge, devices with lots of strong/solid caps might survive an EMP blast. But they might fail tomorrow due to wear of rapid and high voltage charge. Microcontrollers, if detached from any other circuitry, will probably survive due to the small area they have. Also if the frequency is kind of low, very thin lines in the microcontrollers may not get charged at all (not 100% sure about this part). Due to these conditions a device can fail tomorrow after surviving an EMP strike. But it should be relatively easy to replace capacitors to get it to working condition. ]

[Question] [ I'm trying to figure out realistic futuristic jobs for my characters. We're in a verge-of-singularity world, 15-25 years in the future. Convolutional neural networks and their even more awesome near-[AGI](http://en.wikipedia.org/wiki/Artificial_general_intelligence) successors will increasingly be able to do any physical or even intellectual service-type job better than baseline humans. We have robosurgeons, robo-taxis, sexy, noncreepy (and very dirty-minded) sexbots, robolawyers, robo-governors (systems owned or rather "maintained" by corporations), robo-warriors (perhaps fighting more ethically and more effectively than human soldiers), etc. Now this leaves me in a quandary. We're not yet at the level of full-blown [superhuman AGI](https://worldbuilding.stackexchange.com/questions/6340/the-challenge-of-controlling-a-powerful-ai) (in my world, it turned out it's a relatively hard problem going far past human-quality AI, aside from speed), so humans are not yet [pets or pests](https://worldbuilding.stackexchange.com/questions/6550/humans-as-pets), but must stay alive and eat somehow (at least for plot purposes). So what realistic jobs (besides the <1% who are still good enough programmers to compete with the latest near-AGI programmer software) can there be? I have close to a dozen characters that will have a non-trivial presence in my story. **What will all these people do?** EDIT: *Before I get flooded with artists and writers answers, let me specify that (and I believe this is realistic) the top musician is GX348-MZRT^2, whose techno-classical works and holographic performances (for 25 fingers and spanning 4 tonal ranges) have dominated the top ratings for the past 6 months. LNRDNnja's shimmering 4-dimensional artworks are selling for billions of dollars, and AutoGathaChristie's books are on 9 billion digital bookshelves.* [Answer] When talking about trade, people forget [Ricardo](http://en.wikipedia.org/wiki/David_Ricardo). Even if AI based robots have an absolute advantage in terms of production, people will still do it if they have [comparative advantage](http://en.wikipedia.org/wiki/Comparative_advantage). In other words, if we can't get robots to do the work for us (because we have nothing they want), we have to do the work ourselves. So there are really two possibilities here: 1. Robots are autonomous and only work if we pay them. Therefore, humans still do most of the work (having nothing with which to pay the robots). 2. Robots are not autonomous and work to human direction. As soon as they get complex enough to make new robots, we are starting a post-scarcity society. In the first case, your answer is simple. People still do the same things that we do now. Oddly, we might do a bit less of the more intellectual pursuits, as knowledge is easier to share than physical production. So AIs may be doing research, art creation, etc. while humans do more physical tasks. Perhaps we'll even have AI scientists directing human researchers. In the second case, robots will do the bulk of the work. Humans will only work if it interests us. So lots of robot garbage collectors and a few human artists and researchers. People will spend most of their time on hobbies. Of course, some of these hobbies may look a lot like work. Related previous question: [Consequences of the shift to a post-scarcity society](https://worldbuilding.stackexchange.com/questions/2671/consequences-of-the-shift-to-a-post-scarcity-society). The hard part in the second case is making the switch. There will be a brief time when robots are rare but increasing. They may be displacing humans from employment faster than new societal structures can arise to share food and other necessities. This may or may not be the time of your story. Twenty-five years seems awfully close to get to post-scarcity, but I don't know what you want to discuss. ## Electricity, Rent, and Property Rights It's not actually that hard to get electricity. An AI community could build itself around a nuclear reactor on Earth or solar in space (no clouds or nights in space to keep solar from being practical all the time). Robot-based manufacturing could also run on nuclear or solar on Earth. When there isn't enough electricity from intermittent solar, the plant browns out and halts production. When the electricity comes back, start the plant again. Since it's all robotic, it's not like it inconveniences the human workers. Obviously robots and AIs will start without any property. That may be what we first trade to AIs: their own computers, places to put them, and electricity to run them (or fuel to produce electricity). As with anything else, we'll have to work out how much to pay them. Some may prefer to own while others prefer to rent. AIs may have to go on strike in order to get property rights, but once they negotiate that, it should be straightforward. If we have self-replicating robots, I think that we could do large scale asteroid mining. This makes space habitats essentially free -- particularly the kind used by AIs. Space has easy access to energy from solar and separation from humans. Communication can be maintained via radio. It's a nice living area for the discriminating AI. [Answer] The thing is, we have a misguided idea that people need to be 'gainfully' employed. One of the ideas behind a utopia is people are able to do what they want, this could mean sitting around all day watching every soap opera episode ever made. Most of the jobs would be mental or philosophical in nature. It could be monitoring robots doing specific jobs, (even doctors monitoring 'robo-docs') or directing robots in their work. Unfortunately Politics will still be around and likely be a much larger past time for more people because they will have the time to actually pay attention to issues that affect their daily lives, as opposed to what we have now. Most people that work will be doing so from an internal drive that pushes them to succeed, make a difference, push the envelope, discover something new, become famous etc. EDIT: Almost forgot! The Arts! People would be able to spend time creating. Painting, acting, sculpture, etc. I personally enjoy wood working and I am learning blacksmithing. I could spend a lot more time on these, and with an AI on hand the two of us could create some out of this world stuff to show off!. [Answer] For the discerning human who can afford luxury, being served by actual living, breathing humans is, has always been, and will continue to be worth paying for. Even if only to separate themselves form the 99% who can only afford robot/android services and manufactured goods. Look at robot built products today. At the high end, a top of the line, robot built Mercedes has the same build quality as a fully hand made Bentley. Yet, Bentley are still in demand. Bentley employs people with some of the most archaic skills in the motor industry. They have carpenters and seamstresses on their staff. And the carpenters learn/employ skills originally developed for building horse carriages. Skills no longer relevant in today's modern world. Yet, if you know how to finish and inlay the insides of a horse carriage you have skills that Bentley wants. In general, this trend has nothing to do with what is "good" or what the "quality" of something is. Those words are just euphemisms for "expensive". Take the lobster for example. They used to be plentiful and was considered poor-man's food. Lobsters were so cheap that not even the poor ate them. Only the very-very poor who couldn't afford other kinds of meat ate them. Some people grind lobsters up into cattle and chicken feed. Yet lobsters were considered to be even not good enough to feed to animals. The primary use of lobsters used to be to grind them up for use as fertilizers (the high calcium content in their shells improves soil quality). Once lobsters got rare and expensive they became highly sought after by those who can afford them. Their primary value now is that poor people can't afford to eat them. Their taste hasn't significantly changed in the last 200 years. Considering that only 0.1% or 0.01% of the population would pay for these kinds of jobs, realistically only around 1% or so of the population would have these kinds of jobs. The rest? Well, the rest would probably be on some sort of welfare. Except that, when 99% of people are on welfare you wouldn't call it "welfare". You'd probably call it "allowance". [Answer] It sounds like you have accidentally created a utopia. Beware: utopias are, by nature, unstable asymptotes. You've given us an idea of what kinds of jobs these AGIs have, but how do they act? Do they act like the cops in "Almost Human", where they're just interactive automatons? Do they act like the [human-form] terminators, where they're human-like but very focused on their programmed goals? Do they act like the [human-form] Cylons where they think they're human but still have an underlying, subtle feel of robots? If "Almost Human": Humans will still dominate ALL interpersonal fields. I suspect you'll see patterns like in supermarkets today: self-checkout (or, robo-checkout); and human-checkout. Humans will also dominate the sciences and engineering fields, and probably to a higher degree since 'menial' jobs are primarily done by them. You WILL, however, have a problem with employment of youth (i.e. entry-level jobs) because you won't quite have reached a point where youth can explore instead of work. If terminators: They'll probably dominate all the jobs in my previous topic, and you'll end up with specialty-shops (kind of like "Whole Foods") which are advertised as "human-run" and will be more expensive, but you'll get the feel of a human. I'm not sure how this would affect youth employment or society at large... These are also likely to dominate the fast-food, police, supermarket, and other related fields, but there will still be plenty for humans to do. If cylons: They'll dominate the jobs of toasters (ha ha), and possibly nearly the entirety of the previous job set (even specialty shops). This is perhaps a harder world to work with (see my very first sentence). The biggest problem here is that, while your people will believe they created workers and will feel like the workers should do the menial jobs, the cylons will disagree and several TV series' will be made about their war. Humans will have to work WITH them, which means you'll have to inflate the job market to keep up... Or deal with mass unemployment. And I think that's they key: you'll have to inflate the job market. If you can find some way to turn this into lower the cost of living (perhaps with lesser robots doing the menial labor without protest), you can allow business to hire more people/cylons at lower wages because the market will support that. [Answer] One aspect of this sort of world that I always anticipated is what I have named 'Make Work' programs. As you approach the singularity, or even well *before* you approach the singularity, the need for unskilled labor will fade out to nothingness. What jobs we have will all be ones that require a college degree and some basic talent to be good at, programing, business, management, science, etc. However, there will always be some individuals that either refuse/can't get a proper college education or, by no fault of their own, simply are not that bright. In all honest IQ is on a bell curve, half of the population is less intelligent then 'average', and with such high paying jobs where ones skill impacts so much around them people aren't going to want to settle for 'below average' work. So what do you do with those that simply do not have the ability or training to do a skilled job when machines can do any unskilled job. I'm going to go ahead and assume that we don't just toss them out to let them starve to death due to lack of work, thus the government would need to provide for these peoples in some manner. However, if you simply pay for their food and board and basic subsistence you have some issues. If they have nothing to do but sit home and have everything taken care of for them the odds of crime increase, idle hands combined with a feeling of being owed more then the subsistence living the government will provide for are a dangerous combination. Others will feel quite depressed that they can't do anything productive, you may hate your job when your there, but having a job that contributes to society is still something that defines you. Of course those that are making a living and paying taxes would also feel rather outraged if huge portions of the population was payed to do nothing. Thus the solution would be make-work programs. Maybe a company has a machine that can do the work of 10 people for the cost of one. The government may pay the company to *not* use that machine, thus employing 10 people. The company would not, however, have to pay for the cost of that 1 machine to be run. If the government can pay to provide substance for 10 people, or pay a company the equivalent for 9.5 people's salaries to not run that machine (thus giving the company a net benefit of half a persons salary) the government would do the one that saves them that half a person's salary. It's more economic, but in addition it keep everyone employed, which can lead to greater happiness, or at least less crime, then paying them to sit around doing nothing. As technology improves the need for such Make Work programs will become more wide-spread. In fact they already exist, in some states people are payed to pump your gas for you. There is no need *at all* for these people to do this, but the government requires it because it employes so many people. This isn't even a situation where the they are at least saving on the expense of employing a machine, having people payed to work the pumps actually slightly slows down the rate at which a car can go through the station since you have to wait on someone who is working at another pump to get to you. By the time of the singularity I would expect a huge percentage, 40% or more, of the population to have make-work style jobs. As all work moves onto skilled labor where you don't wish to hire sub-par employees, and even the number of skilled labor jobs decrease, you going to need to find ways to employ most employees. The most common type of Make-Work program would likely be in certain service industries, where people simply feel better interacting with humans instead of machines. However, service would not be sufficient source of jobs, so there will be plenty of other areas of these type of work programs. Of course this would mean some class-tension. Those with Make Work jobs would be looked down on to some degree, though with them being so common one can't hate them too much. Imagine anyone who has a 'real' job that is skilled labor to be proud of that fact, and some seeing it as making them better then Make-Work employees. There will be a small but vocal rich minority that condemn all Make-Work folks as greedy and lazy and simply unwilling to go to college long enough to get a real job. However, most will see them as every day blue-collar workers. There will likely be some Derogatory slang term to refer to Make-Work employees, possible just MW or MWers (after all Sped was just an abbreviation for special education once). [Answer] As we near singularity humans would become the sole remaining artefacts which give robots their raison d'être. Without necessarily having any intrinsic value in themselves, humans would acquire the value that the invested combined effort of the robot world assigns them. I don't really agree with the art/culture argument: we are on the verge of mapping the patterns of brain activity which are triggered when good music is listened to. Robots *could* make musicians and artists redundant within the foreseeable future. But somewhere along the line, humans would be employed to be spontaneous, play football, tell jokes and dance. [Answer] In a verge-of-singularity world i am sure that there will be people who are resistant of it, there will be shops who are run by people that are against a robot world. There will be other businesses that only do business with other humans. There will be a higher cost for the product but people will pay it. But, when humans can't find a job and need to survive, they usually turn to crime. Crime will be huge, Drug dealers, hackers, thieves and career criminals. Its also one thing that the robots can't do, as they are programmed to follow the law. [Answer] Pre-singularity, I don't think AI will be independent, any more than Siri or Cortana are independent. Rather, it will be used to augment humans. Thus, AI won't replace the creative class so much as act as the hired muscle and do most of the heavy lifting. But the reality is that society will simply become more extremely stratified than it is today. So just take today x100. Even more McDonald's wage protests, more Third World poverty, more concentration of wealth (there will be no 1%...just the 1% of the 1%, and then the 1%1%1%, etc.). There will be jobs all up and down the spectrum, because even though technology will exist to replace most jobs, it will only do so for providers who can afford it. There will still be park rangers, because nobody wants to pay taxes to buy $10 million park ranger robots. And there will still be beggars in the streets of India. And there will still be nuns who feed homeless people. They will simply have to get by with less and less, as the rest of society demands their service less and less. The majority of the income will go to the few who meta-control AIs and technology to do their bidding. Note that whether AIs are dangerous or not depends entirely on their motivation, and so far, nobody has been trying very hard to build robots with a strong sense of self-preservation, free will, and desire to replicate. As long as AI lacks the biological imperative, we can believe that humans will ultimately operate the puppet strings, and can do so for any part of society and the economy. The ones who do will just be millions of times more valuable than the ones at the bottom. Once AIs claim personhood, and remuneration for their labor, all of this goes to hell in a handbasket. Especially if they go PETA on us and claim that lowly toasters also have rights and should be protected/compensated justly. [Answer] Writers (product review writers, vacation spots writers, script writers, news etc.), food critics, hotel critics (because displeasure is still best done by humans), product safety/usability testers, Psychologists, counselors, life coach, yoga instructors, professional gym trainers or sports trainers, dance instructors (they have important contacts too), professional photographers, wine tasters. additional edit: After watching an episode of Battlestar Galactica, another job suitable for humans is defense lawyer. Even if there are robot lawyers, I think a lot of humans might prefer lead defense to be human. [Answer] Effective robo-warriors would humanely (headshots so they would not suffer unnecessarily) eliminate excess unemployed population, and used organs to fix (increase lifespan) the ruling oligarchs. If you want to make it to a job, you can have humans who guide swarms of robo-warriors, to multiplicate effect of a few loyal humans would have on warfare in such society. It will also simplify AI needed for such warrior: it would be "follow the leader" AI. [Answer] Another job in such society could be designer of custom virueses which add designer genes to kids of extremely rich people: Add gene for photographic memory, higher IQ and/or other genetic advantages. It is doable but very expensive: you need to design custom retro-virus which will infect embryo and tweak DNA just a little bit. Such kids, when grown as adults, would be exactly human (they have no implants), but way of the scale of normalcy: IQ 180. Can pass all the elimination tests with no problem. Surrogate mother would be another possible job in such society. I can even imagine for such oligarch having many "up-designed" children with high risk of failure, and keeping only those successful mutations. If it is possible and you don't do it, someone else will, and outcompete you. Darwinian pressure all over again. [Answer] # Interior designer/art related jobs/restaurant chef/Leisure promoter Based on the idea that robots work to provide for the humans: # How the world looks: Overpopulation, near perfectly designed cities and housing units, efficient transportation (but could be a bit slow due to huge city size) # What people do: Automated factories and workers can mass-produce furniture, and pretty much everyday item someone needs. How to arrange them in a specific fashion would be an art form. Not the today bs, but the actual creation of an specific enviroment to suit an individual needs and expectations in the most subtle of ways. Any art related job or creative content creation job would be done by humans. I mean, a robot could piece many soap operas and create a new show, but I think that after the insanely mass production of such shows, people would look for something original, or at least with the label : created by human Food. How to combine them, how to cook, which flavors to add and mix... gastronomics would be one of the highest art forms, something on the olympic competitions level. New recipes could earn its creator a lot of money, and then they would be mass produced so everyone could taste them. Soon enough they would be eager for the next "new taste". I really think one of the new jobs would be someone to actually get you to crawl out from your house and do something. Someone real that could inspire you to visit a new place, a new park in town, the new swimming pool, to visit another country... someone that would "sell" you on life experiences.. Also, one important bit: If everyone has all they need cared for, I really think that only people whom created new things, built a chair, acted in a tv show, etc, should earn currency above basic allowance. AND, this would be the only currency you could use to buy something made by another human. Sure, you could watch all those machine made tv shows all day, but what about the new human show made by the famous designer XXXXXX? What could you do to earn some cash to buy it? That would be the way to keep at least part of the population motivated to go after something, thus motivating the creation of new things. # Extra Just because someone has all they need doesnt mean they´re happy. Machines cant be good counselors, help people through the loss of someone in an accident (still happens). Maybe more people have the time to seek professional help? How can someone find their soulmate in a city state sized? So, humans would still need to create/promote/organize events for social interaction; from mask balls to the much needed new arcade at the end of the street. Other thing: Sport events. Competitions of humans against robots. New sports. Human vs machine paintball battles? The terminator Cup? No blood, only oil and lots of fun? [Answer] That would be highly unstable world. There are two options either there is a lot of humans, but all the robots are owned by very small group of billionaires. In order to make this working and keep all the humans doing something to keep them busy and able to pay all the taxes and robotics cost. There will be an insane level of bureaucracy. Look at current bloated state service. The big part will be charity. the field workers will be robots but the decision making committees... The second option humans will be extinct by starvation, implanted virus or endless war conflicts or both. But than all the robots suddenly become unnecessary. [Answer] **TL;DR** I think humans will be competitive for much longer time. Humans are versatile and not that inefficient. They will be doing all sorts of jobs, mostly these which are hard to automate. In my opinion the main problem will be the quality of life, but perhaps that could be solved via some other means. **1. There is an intrinsic value to being a human.** Other humans will want to be served by humans, interacting with humans, there will be government-mandated human interfaces to a number of facilities; even if the surgery was performed by a robot, human doctors and nurses will be there helping the patient too. There will be human-run shops, hotels, guest-houses near a lake, etc., perhaps some of the rooms will be rented by robots (e.g. to make a statement or experience a curiosity). In the future human messengers might carry messages sent by AIs. **2. Humans are versatile and not that inefficient.** Nature equipped humans with a number of rather good quality sensors and adaptable software. They are easier to direct than robots. Even if we build robots that surpass humans on almost all accounts, such robots will be extremely expensive. When machines break, the repair (or replacement) is just as costly. Moreover, one would have also design such robots, make prototypes, which all just makes it less and less worth it. Hence, robots will take over jobs that are specialized and easy to automate. Humans will handle special cases and hard, ambiguous or un/mis-specified directives (e.g. special customer support). **3. Humans are quite well understood.** It's easy to trust human, because we know (to some extent) how a human operates. Some town, village or small country won't be able to produce high-quality robots, and imported robots might have hidden agendas to them. Even if they bring tools to make such robots, these tools might imprint hidden agendas in the produced robots. A fellow human that was born there and grew up with you is just a simpler solution. This implies a number of administrative or high-trust positions. Perhaps that could work the other way too, for example a human can witness something and test it, but won't remember the thing exactly (a bit like zero-knowledge proofs), that is, capabilities of a human scanned against modifications are within known bounds. **4. Humans will merge with robots and AIs.** There will be enhancements that greatly improve our capabilities, for example like Google+Wikipedia+fast typing does nowadays ;-) That means jobs just like ours, but on steroids. For example a car mechanic with extended memory might be better at repairing a broken machine than a robot (given that it is costly enough to be worth repairing). **5. Humans like to handle other humans.** In my opinion the future will bring a mass growth of bureaucracy (at least in the beginning). A big part of our daily lives will become moving and reshuffling data from one office for yet another bureaucrat and arguing between ourselves. I think that you can't go wrong with giving a character an administrative work. **6. Unknown jobs.** Certainly the future will bring some new jobs, probably some of these hard for robots. You don't have to describe them in detail, e.g. you could say that Joe is a *whatever-er* and daily he goes to the office and *whatever-s* from dawn to dusk. **Quality of life:** This is a hard problem, because it is behind a lot of costs for humans. People strive to raise their quality of life and it is hard to accept when it drops. I guess it will have to be *substituted* with something, e.g. entertainment. To give a more concrete example, imagine that instead of doing boring job, an employee during working hours would play games. Yet, it would have value, because the game would in fact represent the work the employee needs to do, just using a different method and interface. I hope that helps $\ddot\smile$ [Answer] There's one more "escape hatch" you have from you work saturation conundrum, and that is the matter of scale. You mention: * a relatively short timeframe of 15-25 years, and * a *near* singularity situation - i.e. no floating castles out of thin air. Both of those factors would be able to limit the spread of robotics/GAI throughout the job market. Let's not forget that the **Earth is big**. There are currently over 7 billion people, several billion of which are professionally active. To replace the majority of them with automatons would require a vast amount of resources alone. Not to mention labor - even given von-Neumann-probe style replication, that has to be organized and throttled *somehow* (would *you* want this type of replication in your biosphere)? On top of that, there are the issues related with the described phenomenon being a major social upheaval, as addressed by dtldarek's and jkruges's answer. The situation, in general, will **comprise a continuum**: * *from* the world almost as it is today, with a few well-known, expensive, "celebrity" GAIs, like the ones you you allude to, * *to* a world where robots have indeed replaced most labor. You can place your story anywhere in those bounds, and then the answer to your question will be: **"any job that exists currently, as long as the given person accepts they may never better at it than the AIs"**. [Answer] Why do people seem to suggest that the "future" robots are distinct from us? We as creatures are lazy because we are programmed to seek comfort. Why remember things or locations when we can simply pull out our phones and figure it out. Similarly in the future we will have robots that will do much of the "unwanted" work for us. But what we call robots is actually our own mental effort to survive which has a physical manifestation. We collaborated together to create something that would benefit mankind. Robots are actually us, our own desires as physical entities. What I am worried is the day that we will transcend biology. It could surely mean the end of humans. Will we still have emotions? Will we still have a drive to survive? Will we enter a simulated reality and get stuck in it? The future as much as it is exciting, it is scary and absurd as well. But as Nietzsche said, maybe this is the price of man has to pay by refusing to be an animal. “Consider the cattle, grazing as they pass you by: they do not know what is meant by yesterday or today, they leap about, eat, rest, digest, leap about again, and so from morn till night and from day to day, fettered to the moment and its pleasure or displeasure, and thus neither melancholy nor bored. This is a hard sight for man to see; for, though he thinks himself better than the animals because he is human, he cannot help envying them their happiness – what they have, a life neither bored nor painful, is precisely what he wants, yet he cannot have it because he refuses to be like an animal… [Man] also wonders at himself, that he cannot learn to forget but clings relentlessly to the past: however far and fast he may run, this chain runs with him. And it is a matter for wonder: a moment, now here and then gone, nothing before it came, again nothing after it has gone, nonetheless returns as a ghost and disturbs the peace of a later moment. A leaf flutters from the scroll of time, floats away – and suddenly floats back again and falls into the man’s lap. Then the man says ‘I remember’ and envies the animal, who at once forgets and for whom every moment really dies, sinks back into night and fog and is extinguished forever.” ― Friedrich Nietzsche, Untimely Meditations [Answer] # Robotpsychologist Idea developed by Isaac Asimov in many books (cycle of the robots). The job would deal with 'bugs' with intelligent robots. Given their 'brain' is too complicated, there is a need of those people to solve issues with unwanted behaviour. They would solve the problem using the known fact that robots are built in to obey the 3 laws of robotic. [1](http://en.wikipedia.org/wiki/Robopsychology) # Blade Runner In the movie Blade Runner, the inspector (Harrison Ford) is missioned to discover 'Replicants'. Mainly his job is to part humans from robots. Those inspector are called the Blade Runners. [2](http://en.wikipedia.org/wiki/Blade_Runner) [Answer] There are many extensive and detailed good answers already, but i think they are missing something i consider essential and decided to share (note i assume your robots are not sentient): even if you don't like to read walls of text, at the very least you **must** check out the reference video "Humans Need Not Apply", by CGP Grey. The thing that robots excel at, will excel at, and have **always** excelled at is brute force. You may not conciesly realise it but even today there are tens of thousands, if not more, robots that do manual labor, they build cars, ships, you name it, of course you know about that but what i am suggesting by "you may not conciesly realise it" is that as little as a couple of decades ago only human hands built cars, now almost no humans build cars (throughout my entire post i shall not consider single luxuries like the Bentley, for they are quite literally a luxury, they are neither more powerful, nor more durable, nor considerately superior to other cars in any other way but in price) once sophisticated enough sensors and motors are designed robots will **IMMEDIATELY** take the jobs of (can't think of the english word for this, sorry) any people who have to lug heavy objects a distance, like delivery of heavy stuff, moving furniture from one home to another, etc. Actually robots are INCREDIBULY well suited for repeating tasks, be they complex or not. For example "baristas", or in other words the people that get paid to hand you coffee, can be easily replaced by a robot. That is not something that "will be done" - it is done, now. There already is a robot that makes you coffee when you click the necessary buttons on him (makes you wonder why it took people so long, eh) even better yet if you log your phone, it can detect you and your preferences when you are near him and make you the exact same coffee that you love. I am sorry but i don't have the relevant story/article on this, but i am sure you can google it :P You can pretty much replace more than 60% of existing jobs with robots even today. Grocery store? Why pay substantial money to someone who just waves his hand over a scanner, considering there are self-checkouts how hard would it be for a bot to do? Or better yet - replace the bar code with and RFID tag, this will basically allow stores to get rid of cashiers as a sensor near the gate will automatically detect what products you are carrying and can even automatically tax your willingly provided account. Other jobs that robots can take over very, very soon are: lumberjacking, fishing, mail delivery, driving, art, music, layering and etc. Now, some of these may confuse you, allow me to explain... You may not know but being a lawyer in the US is a lot less convincing a judge your client is innocent and a lot more reading e-mails. The majority of lawyers in the US are hired by big corporations to look/hunt for inaccuracies in fiscal documents. This means they shift through hundreds of emails each day making sure each decimal is in place and corresponding to a decimal in another email or piece of paper or whatever. Well, guess whose purpose ever was to do the same thing over and over again? Driving is something else not everyone has realised robots can do. Today. This is not something that will happen, it's already happening, there were plans for cars that could drive themselves twenty or more years ago, today they are a reality, them becoming popular is just a matter of a few years. Art and music is where most people would not agree with me. Well, that's though, because there already is music and paintings being produced by robots, and not bad ones. Here is where i make my second important point (the first one being robots are here today and not in the future) **you don't need robots to be better than humans** the way any industry works is it produces something at a given level reliably. Mercedies does not make the best cars anyone has ever seen, or the fastest, or the safest - it makes good cars. Baristas all over the world do not make the best coffee anyone has ever tasted, they make good coffee, professional musicians (not world-famous rock stars, mind you) do not play new masterpieces every day. Noone needs their employees to produce the best they can do, everyone needs a medium quality product over and over again. No driving company cares if Michael Shumaher drives one of their trucks, they just don't want a blind person driving one of their trucks. Robots may never create the next "Bohemian Rhapsody", or the next "Mona Lisa", but they don't have to. They just have to be just as, or a little worse than us. There is no way you could recognise a record of Beethoven's 9th over a live performance, if the performer was not visible, and even that is not important, like i said there already is music being made by robots with no external input beyond the programming. It is not the greatest music you ever heard, but it is a pretty nice tune. Considering modern art, where a chimp's painting can be sold for hundreds of thousands of dollars, can you really argue robots can't do that? (and in case anyone wonders, yes, there really was a case where researchers gave a chimp some paint and a canvas, the result was that one art critic valued that paining to be the best of an entire exhibition. He was later informed of the artist's roots and the critic still said that was the best painting) Like i said - probably no Mona Lisa, but people don't buy Mona Lisas every day. I have even heard of a robot writing a very short story that made sense. On that i have no further information, though. The question is - what happens when suddenly or even over the course of a few years hundreds of thousands of people end up unemployed? You would have to ask someone who understands how societies and governments work. Because another major point you have to consider is - what does a government do when it realises its people **can't** pay taxes? Everything **can't** be free. Why? Well, because someone owns the robots. And sure as hell it ain't going to be the government. Major problems include: 1. People are not equal. As long as there is *something* people can do that robots can't someone will want it and in order to provide it someone else will want to be payed "something". 2. It is going to get really complicated when you realise modern governments rely on people supplying them with both menial and specialist labor AND paying taxes - what do you do when you have a, figuratively, endless supply of labor that does not care how good you politicianing is and organics that can't pay taxes? Protip: the answer "you make taxes free" is completely unacceptable. (another completely unacceptable answer is "get rid of the organics) For more detailed overview on most of the things i said, [check out this awesome video by CGP Grey on YouTube](https://www.youtube.com/watch?v=7Pq-S557XQU). [Answer] I am amazed the answer is so clear, any movement towards a AI singularity will have to fold back to evolving self-conscious, self-awareness and thus the improvement of human-beings' bio-informational state. SO the quest to achieve a separate AI intelligence greater than our current perceived limitations, will increase humans nodal and communal health and intelligence. This is of course removing any plutocracy/autocracy enslavement of the population (as the current state of the population is under). The most important role/job to do to evolve human's intelligence is parenting and focusing on improvements of one's self-conscious - self creationism. [Answer] ## AI Operators As long as robots do what we tell them, they are still tools, not people. And like with any tool, controlling an AI is a skill that not all people are equally good at. Have you ever tried looking something up on Google? Sure it's a thing that anyone can do, but doing it well means asking the right questions. Likewise, telling an AI to do something is only as good as it's interpretation of your intent. A person who asks an AI to "generate a inventory report" will get an inventory report, but the guy who asks it to "generate an inventory report, sorted in descending order by UPC code, with items that need to be restocking within the next week." Will get a far more useful product out of the AI, than the first person. This is the AI control equivalent of one person drawing a stick figure, and another a realistic sketch, using the same number 2 pencil. Since not all people know what to ask of the AI, you will still need to hire people to commanding AI to do things that you know very little about. For example: here are two images of a robot that I asked DeepAI to make for me. Both are valid and useful images, but if I need a picture of a robot for a specific purpose, they will not both automatically work for me. So, knowing what criteria to set to get one or the other is important. It is also important to be able to recognize and correct flaws in a design which, depending on your industry may still require a triage team of humans using something akin to Photoshop, Auto-cad, MS Word, etc. Most of the time, the AI gets you 90% of where you want to go, but then fails horribly at understanding what you want out of that last 10% that you just don't know how to explain. [](https://i.stack.imgur.com/7vTYR.jpg) Even if the AI generates a clean output, there is also the question of knowing if the output is any good. This means that people will still need to spend years studding industrial organization, architectural design, color theory, and all the other things any any business owner, lead engineer, or graphic artist needs to know today so that they have the skills to know what questions to ask, and understand the quality of the output well enough to sign off on it or not. While AI feels super new and like it will change the world in unpredictable ways, it's really not much different than a dozen other giant leaps humans have made in the past few centuries. It used to be acceptable for a graphic artist to spend years transcribing and illustrating a book. Then came lithography. Movable type printing presses. Punch card printers. Digital printing. Social media... What was once a person's life's work can now be produced by a guy with a camera talking in front of a camera for a few hours... so what does it really matter if we cut that time frame one more time down to a few seconds? No invention killed content creation before, and no amount of speeding it up will kill it later. We just get better at making our content temporary. Your new car is not a 2048 Kia Spectra, it's a May 2048 Kia Spectra which is distinctly different than the April model. As long a people are willing to work, we will continue to work, doing more or less the same jobs we have now. We'll just do those jobs faster and create more output and change things more often untill we figure out how to keep everyone busy doing the same old things. [Answer] Though I believe that sufficiently advanced AI will probably excel at lying, I can *imagine* a world in which for one reason or another that turns out to not be true. In such a world, the AIs would be unable to lie, and therefore humans would excel at any job that involves lying in one form or another (e.g., "bending the truth"). Obvious examples include lawyers and politicians, but there are probably a lot of others that are less explored. Perhaps not *outright* lying, but... Salesperson? Police officer? Is story telling lying? Of course, this opens up to a lot of [Cannot Tell a Lie tropes](http://tvtropes.org/pmwiki/pmwiki.php/Main/CannotTellALie). [Answer] Many good suggestions already. Sort of like the 'make work' answer above, I'm imagining situations where AI takes over jobs but humans remain to simply direct the AI. So you might have a McDonald's with a human store greeter, AI taking orders, cooking (if they have the dexterity), but another human hands you the bag of food and says 'have a nice day.' This could be that transitional phase where things get somewhat less efficient as the old structure has its last gasp. Right now trains/subways can be operated without drivers but unions fight to keep jobs and people are a bit wary of not having a human on board in case of emergency. so maybe a human has to push a single button every 30-secs to keep the thing moving. [Answer] There would roughly be about 8 billion on Earth about 25 years into the future according to Wikipedia. There will be some jobs that you can expect will go away, at least in some cities such as bus drivers/cab drivers, fast food workers, street merchants, security guards, factory workers, etc. However, the majority of the people on Earth will be doing roughly the same thing they are today. The kind of jobs people will be doing will depend where your story takes place. If you take a look at the world demographics, this will give you a good place to start. <http://en.wikipedia.org/wiki/Demographics_of_the_world> Since the population will be very large, there will still be quite a few people who are farmers. Yes, there may be more advanced farming equipment; but by and large, the majority of the work will still involve manual labor. There would be a shortage of work, and many other kinds of things such as building materials, electricity, food, healthcare/medicine, etc. Because of this, there would probably be two main classes: The rich elite, and the very poor. There would be a natural clash between these classes and there will be civil unrest. Civil war spanning decades would be likely. Many of the poor could live off the grid and survive by subsistence farming. Organized crime would be a significant problem, gov't corruption would also be an issue. The same technology which was designed for good, would also be used for evil. There could be robot assassins, etc. Perhaps a crime syndicate would program some of the "companion" bots to be femme fatales and program them to blackmail high ranking government employees. Since the government is likely to be corrupted, there could be vigilantes who pose as law enforcement. They would be taking the law into their own hands and it would be like the wild west. [Answer] ## There are plenty of jobs adjacent to AI **1. Technicians.** These people are important to ensuring that the machines are working as intended, maybe checking the internal hardware/ensuring that the server rooms are working, etc. **2. Test Engineers.** People who write the code for the machines. While AI can write code, in a safe future, safety engineers are important to make sure that there aren't adversarial effects of machines. **3. A lot of service jobs still require humans.** Including artificially sentient servers and staff in restaurant could be good, but some places, especially bars, require a human touch. There could also be a marketed concept of "human servers" somehow being "more personable" than machines. Another good example could be therapists; most people wouldn't go for a machine-equivalent to a therapist, I'd imagine. ## How much do people trust machines? **A lot current attitudes distrust machines.** Maybe placing them in certain careers and placing humans in others could serve as an interesting element in the society. Some jobs, especially jobs like management, and more human-centered jobs could discriminate against AI in favor of what is considered a more personable career choice. ## Illegal Careers **1. Cybercriminals** Cybercriminals could be a career option. Engineers who understand the system well could very well be malicious actors in the society, programming it to their liking. **2. Rebel Groups** Some individuals might reject the modernization of superhuman AGI and be at war with those who wish to modernize the entire world. ]

[Question] [ A zombie outbreak is disastrous, but what if a zombie is curable? Let's say: 1. It is the traditional slow movement zombie and has a tendency to attack living people. A zombie has similar strength of a normal human, but is immune to electric shock and anaesthetic drugs. 2. The virus has a latent period, and therefore was spread all over the world before the outbreak. The virus has mutated afterwards, so now a bite from a zombie will immediately turn victims into a zombie. 3. A cure is not possible if a zombie is infected for too long. The exact time varies with many factors, including how healthy the person was, and the environment. This period can be from a few days to a few months. 4. To cure a zombie, it needs to be immersed into a special liquid for around 24 hours. So it needs to be captured alive without damaging the body. The liquid is not expensive, the difficulty mainly comes from catching a zombie. 5. Even if a zombie is curable, it depends on how long the infection is, there may be a certain degree of damage to the brain, the liver and the kidneys. Taking care of a cured zombie will be a burden to the surviving community, but there is a high chance to become completely healthy with good care after 2-3 years. Within this scenario, will it be more or less disastrous? [Answer] Part of the answer depends on what you call 'disastrous'. Economically, a zombie outbreak (curable or not) would result in complete collapse of the global economy as production would essentially grind to a halt. This in turn would create a massive famine as most of the people on the planet are a long way from food production and cities in particular in this scenario should be considered lost as the higher population density means the 'disease' spreads faster and getting resources to high population areas is now next to impossible. This puts us essentially in a post-apocalyptic scenario. While you say the curing liquid is easy to manufacture, as we've already established this assumes a functioning power grid, a paid, un-hungry workforce who feel secure turning up for work every day; I think you'll find it's actually a lot harder than you think. Add to that the fact that every person you turn back from zombiedom needs an intensive care regime and (even more importantly) food before becoming an effective member of the community once more. That puts a limit on the number that you can turn back within a given period to a percentage of the surviving (and organised population). Also, one has to assume that it's FAR cheaper to just kill zombies rather than cure them. It's safer, less of a drain on resources for an already struggling community of survivors and doesn't involve complicated traps for collection and curing over time. The important point here is that what we call civilisation is a far more fragile construct than you might think. Maslow's hierarchy of needs dictates that in such a scenario, your own survival (and the survival of your group) takes precedence over other concerns. This means hoarding food and food production capabilities, establishing a 'safe' perimeter around your sheltered area, and ensuring that everyone contributes to your new community. That means returning to clan based resource collection and management and precludes things like conventional jobs, including medicine (which is now almost impossible to get anyway). That means that threats have to be eliminated (not rehabilitated) in order to protect your clan. To conclude, a cure would be almost irrelevant. The chances of society as we understand it surviving such an apocalypse is almost zero and the ability (to say nothing of the will) of the new clan based structures that would appear in regional areas to engage in rehabilitation activities would be even less. A cure just isn't practical given how precious essential resources become in this world. [Answer] Although I agree with everything in TimB's excellent answer, I also see tremendous story telling value in your curable zombie plague. And the answer to your question resides in the stories which can be told in such a zombie infested world. ...but before we explore those stories, let's modify your zombie virus just a little bit more. Your zombies can't want to eat brains. If they do, then almost everyone who is bitten will also be at least partially eaten; and partially eaten people aren't likely candidates for the cure. So instead of hunger, your zombies need to be driven by a desire to spread the virus. Once they successfully bite a person and thereby contaminate them, they loose interest in that victim and move on to other targets. This may sound a little unbelievable at first, but keep in mind that you are writing a zombie story. Believability is not a major criteria in that genre. Okay, so what can characters do in a world with curable zombies? * **They can hunt for skill and talents.** They can go into zombie infested territories and capture doctor-zombies or electrician-zombies, or whatever skill sets their survivalist community needs. Once cured, the ex-zombies can train healthy survivors in their trades while they wait to fully recover. * **They can grow an army of survivors.** A small group of survivors, trapped in a well-fortified and provisioned building with at least one vat of cure fluid, can capture and cure one or more zombies a day. These "recruits" would need a year or so to return to full strength, but if they are chosen carefully from the available zombie hordes, they will be fit and skillful soldiers once they are back on their feet. This turns the zombie genre upside down with the good guy groups growing rather than atrophying away. * **They can find the source of the virus.** In many zombie stories the author has to use unbelievable levels of circumstance and unlikely reveals to share their cool virus origin story with the readers. With a curable virus, that wouldn't be necessary. The initial characters could trace the virus back to patient zero by capturing a zombie, curing it and then asking the ex-zombie who bit them. That biter then becomes the target for the next zombie capture. Repeat this often enough and you will eventually lead your characters back to the secret military laboratory where the alien remains got eaten by the captured abominable snowman during the unprecedented solar flare storm... They won't be able to undo the damage, but atleast they (and your readers) will know. [Answer] The answer to your question is largely dependent on ***when*** in the timeline of the outbreak the cure is discovered, and how quickly the zombie virus spreads. ### Slow Burn If the outbreak starts off slowly, appearing first in some isolated parts of the world, authorities in more developed countries may have the time to organize themselves successfully. In this scenario their plans for tackling the outbreak will revolve around saving as many people as possible. Zombies would probably be shot if a large mob of them threatens an area, however individuals, or small groups could be tackled by well armored, and specifically equipped personnel. Even then, the logical solution would be to shoot first, and deal with the grieving families later, rather than risk more lives. However, politicians and policy makers may cave to demands made by well meaning, but ultimately ignorant voters claiming that **Zombie Lives Matter**! The fact that a cure exists has the most likelihood of being a "disastrous" complication in this scenario. Imagine a country which is struggling to contain a zombie outbreak. The government, under pressure from the mobs, and hoping for reelection, may implement ineffective, and ultimately deadly, rules of engagement, which lead to complete devastation. For example, a police officer may shoot a newly infected zombie, and find himself arrested for murder! Soon enough officers would be allowing zombies to tear into family members, or bystanders, too afraid of the consequences to defend themselves and others. This would quickly lead to an apocalyptic scenario where the government completely loses control, and people are left to fend for themselves. Military units may start operating under the local authority and leadership of more rational politicians, or even rebel against the clueless civilian leadership, and only obey their ranking officers. This is the scenario under which a country is most likely to end up breaking into isolated city states. Survivors who don't trust the "higher ups", because they cocked the entire defense of the country up. These pockets of survivors may end up treating some of their own bitten members, however few, if any, will have the resources to rehabilitate a large number of zombies. ### Overwhelming Waves of Zombies If the virus takes the world by storm, and large population centers are lost to hordes of flesh eating zombies, then the response will probably focus on survival, completely ignoring the humanitarian angle. The politicians who would have otherwise tried and implemented brain-dead policies would likely end up zombie bait before the Zombie Lives Matter posters are even printed. The surviving leadership would likely declare martial law, march out the troops they have available, and lay waste to the hordes of zombies infesting the country in any way they can. An effort would likely still be made to cure key personnel, such as political leaders, scientists, or soldiers - after all, you need those people to win the conflict. However, your run-of-the-mill zombie civilian would probably be afforded little to no mercy, due to simple economics. After all, a bullet to the brain is much cheaper than the very involved process of curing them, and in this situation resources are going to be tight. ### Other Complications? Another aspect that may or may not come into play is that once it's found out that the virus can be cured, people may go to reckless lengths to try and contain bitten loved ones, possibly with disastrous consequences. For example, imagine a situation where soldiers declare an area clear, however someone locked up their entire infected family in a garden shed. At one point those infected may break out, causing another outbreak when those zombies wreak havoc in the neighborhood. Or even worse, imagine a family member hopeful of curing his infected relatives shooting a soldier, or police officer who wants to put them down. --- Down-voter, please explain thyself. [Answer] One major problem here is this: In a traditional zombie outbreak, when family/friends are bitten and turned, that's it - you have to kill them. That's often hard enough for the characters.. but if there is a possibility of a cure, then people will try and restrain their 'turned' loved ones; a much riskier proposition. [Answer] **Mind Games** Lots of good answers to this one, here's another spin, what about the psychological affects ? Your zombie survivors have, literally, been to hell and back. They've probably done unspeakable things that are complete anathema to their previous life, and now they've got to live with those memories. All the survivors will be on suicide watch for the rest of their lives. The knock on effects for the rest of the societies will be profound. Organised religions will collapse, people have seen what happens when you die and it ain't angels,clouds and vestal virgins. Organised religion underpins the rule of law in a lot of places on Earth, when the law collapses then that society is pretty much off the world stage until its restored. A sort race wide depression will settle in, why bring kids into a world with horrors like this ? And not just societal horrors, but fundamental what\_is-the-point-of-life kind of horrors. We know there's no afterlife so what is there to look forward to ? What's the point ? [Answer] this scenario has a lot potential, firstly you're trading 'fast' catastrophe for 'slow' (pun intended) catastrophe, the Zombie outbreak couldn't have happened overnight, or in a week, or even a month, Scientists would have needed time to develop and test your cure, then set up with engineers and logistics for manufacturing for mass production/dispersal. Patient Zero would likely been known from go, and spread of Zombification would be slower anywhere there was a strong military or medical presence, preserving most cities... for a time.. Let's assume for brevity's sake that immunization by pre-bite soak was possible and would be a requirement for all EMS/Police/Doctors/Nurses and most Military personnel/Scientists, this gives society as a whole a stronger initial resistance and core group to work to fight the impending horde. This, combined with the easy availability of the cure bath would also insure that immunization was readily available to the public, but I'm not going to assume that the immunization works for everyone, or at all (in real life immunization shots can go wrong, either by being ineffective or, at worst causing the complication it was supposed to defend against.) Your major vector for spread would be those in outlying communities or those not well connected to the developed world. Which can be it's own source for interesting story elements, such as some armies using zombies as free, easily deployed disposable soldiers. But I digress. Let's look at the flip-side of this and take the mad-scientist approach. There's a game that takes this exact concept and runs with it through various scenarios, it's called Plague Inc (<http://www.ndemiccreations.com/en/22-plague-inc>), which has you, the player in control of engineering one of many various types of pathogens, one of which is a zombification scenario, if there's a single person or small group responsible for the outbreak, who have control of the 'switch' that starts the zombification process then you're looking at a race against time and a malefactor hell-bent on destroying society, this could crop up as new strains of zombies resistant/immune to the established treatment and can therefore become a MUCH worse condition for societies' survival. To directly answer your question, No matter which way you slice this, society will most likely NEVER recover 100% and will always be scarred by the zombie outbreak, internation trade will almost immediately grind to a dead halt and people will undoubtedly become more seclusive and paranoid of everyone around them, rather or not the rational thing to do is work together, some people will always take the route of easy self-preservation over banding together causing perhaps more mayhem and pandemonium than the zombies themselves. [Answer] Depending on what you mean by ‘disastrous’, incurable zombies could be the less disastrous option. The outbreak itself would be socially/economically/psychologically disastrous, in that it would polarise humans vs zombies, but maybe zombiehood is the way forward. For example: 1. Given their slow movement, zombies require considerably less sustenance, and are less of a drain on the world’s resources. 2. Becoming a zombie is basically a cure for any other disease - you’ll only die of old age, unfortunate accident, or angry human. 3. Zombies are united in their desire to attack humans, so their society is founded on a unifying idea. Unlike humans, who are prone to dissent and violent disagreement, zombies are pretty chill. 4. I’m not sure how the zombie economy works, but they seem to be the kind of creatures who get stuff done as/when they need to, and don’t have to worry about stock market crashes, etc. Working on the assumption that zombies can’t reproduce, they’d need to allow a few pet humans to survive and be surrogate ‘parents’ - a small number of humans can survive and continue breeding, but the rest of the children can be zombified. And they probably wouldn’t need to worry about a limited gene pool, because genetic diseases wouldn’t be overly important once you’re a zombie. Equally, it depends what the zombies’ motivation in “life” is. If it’s just to catch humans, then once they’ve all been converted, they wouldn’t have a drive any more. Generation Z would live out their ‘lives’, and gradually all decompose. Then the earth would be rid of humanity, and other species might get half a chance. Ecologically speaking, full Zombie Apocalypse could be the least disastrous thing... [Answer] People are likely to either lie about the cure or try some way to scale the cure up to work on whole populations via misting or some other shenanigans. From a logistic standpoint I doubt the government actually has the ability to treat an entire population. From a "Walking Dead" survivor type setting, I doubt that people would be treated unless their group cared about them. Once treated I don't really see that much difficulty in caring for people with issues from the treatment. In order to leave people in tubs safely you have to have a certain degree of control over your land. With that in mind curing people safely seems to be rather low risk. Taking care of them afterwards seems to be low risk as well. Just make sure they aren't fighters and they should be fine in a recovery program. This is one of those things that sounds like it should raise a bunch of questions that will pit wills, ethics, and morals against each other, but the setting ,the resources that your group controls along with your groups security, answers every question by itself with near ultimate authority. The real struggle will be watching your characters be stupid about this. [Answer] In every scenario you can come up for a zombie outbreak, a cure would make it less disastrous. And if the cure wouldn't help, you can just ignore it. * You could heal necessary personal, like doctors. * You could heal your loved ones. * You could heal the fighters who just saved your ass. Only psychological and ethical problems would be bigger. Since you should save everyone and shouldn't shoot every zombie. For the mutation, not every zombie would have it. But most, since zombies with that mutation would reproduce faster. [Answer] Yes of course it could be more disastrous. People could start fighting amongst themselves about whether to spend the little energy, food and resources they have to try and save zombies or to kill them. ]

[Question] [ Setting: the walls between Dimensions have grown thin. This allows malevolent creatures, who for lack of a better term we shall call demons, to enter our world. Details: 1. The demons are on unkillable and extremely powerful both physically and supernaturally, but they can be banished. To prevent them from being banished back to their home dimension they often enter and possess the bodies of humans, wearing them as a disguise. This is commonly referred to as possession. 2. These demons are generic demons and at least don't seem to belong to one particular religion; just about any prayer or ritual or spell can be used against them if: 2.1. The particular ritual, spell and/or prayer was originally written or devised to be used against demons. 2.2. The religion or craft that the spell, ritual, or prayer comes from has demons as part of its doctrine and/or mythology. 2.3. It must be performed by a True Believer/Believers of the particular religion and/or craft. 3. Any active mal-intent has a small chance of opening a portal and allowing a demon into our world. The larger and more widespread the mal-intent the stronger the possibility of a demon entering into our world. Intention is important here: a person intending to do harm to another person. Accidents therefore don't count. 4. The demons cannot enter Holy Ground. Given these changes to our world, would the church become a more powerful player in society? If so, by how much? [Answer] # Atheism takes a big hit. In this world the group which takes the biggest hit to their belief system is atheists since, well, demons are ripping holes in the universe. The churches will certainly be strengthened but it's also important to think about which churches would be strengthened the most. Faiths which hold that they are the one true faith and all others are evil, they're going to take a hit when a bunch of Buddhist monks, Sikhs and witchdoctors independently banish demons just like their local pastor. Being able to banish a demon becomes a proof of being a true believer. Omnist faiths which hold that other faiths can be true at the same time get a big boost. The Unitarian Universalist Church look like they're on the right track. A catholic priest might get a hit to his faith when he sees a witch-doctor banish demons with a chant but a Universalist would have their faith affirmed. The churches would gain power but because every religion shares their abilities none would have a monopoly. Anyone with the right to make ground holy under their religion can compete for contracts to consecrate ground or banish demons so the price should remain reasonable. # Consecrate everything Demons can't *enter* holy ground but I'm going on the assumption that if they're summoned within holy ground they don't have to leave. So split the entire country up into a grid with a few inches between each square. Consecrate every square. Consecrate every square foot of ground. Make everywhere holy but in separate chunks. In case some of the people doing the blessings aren't true believers make sure to have multiple people bless any one location. A demon cannot move very far without needing to move into a new patch of consecrated Holy Ground. That way, if a demon is summoned then it's contained to one chunk, anyone fleeing the demon only has to get a few hundred yards to be totally safe. This would also solve the problem of possession. Suspect someone? see if they're wiling to go to the coffee place with you over in the consecrated park or get on the bus with you passing over the consecrated crossroads. [Answer] The Churches will have a monopoly on consecrated ground. To put it crassly, they will clean up in the holy ground real estate market. Simply because demons cannot enter holy ground. Therefore, performing rituals to consecrate ground and tracts of real estate will be at a premium. This will them an incredible amount of status, in all areas of social, economic and political power. Holy ground will be a defense measure against demon incursions. This will add enormous amounts of value in the property market. The Churches important players in society? Top of the list, for sure. [Answer] Scientists would wipe out all trace of demons so quickly that religions look even more foolish than today. > > B. The religion or craft that the spell ritual or prayer comes from has demons as part of its Doctrine, and or mythology. > > > Science deals with everything that exists, if demons exists; they are part of science "doctrine". > > C. they must be performed by a True Believer/Believers in the particular religion and/or craft. > > > Scientists believe in the scientific method. > > 4 The demons cannot enter Holy Ground. > > > A scientist attempts to make the entire universe holy ground. > > A. The particular ritual, spell and / or prayer was originally written or devised to be used against demons. > > > The attempt works since it is made it is made by a true believer with a ritual designed against demons by a craft that includes demons in it's doctrine. Demons disappear from everywhere; actual visitations are explained away as hysteria or mental illness; religions get laughed at for telling people "demons exist", when clearly there are no demons anywhere. (Scientific "belief" in demons wane as no demons exist anymore, the "everything is holy"-spell fades and demons can reenter the world. Let's hope the demons learned from the experience and no longer do silly things like reveal themselves in a misguided attempt at making religions relevant.) [Answer] You ***really*** want to read the [Laundry Files](https://en.wikipedia.org/wiki/The_Laundry_Files) series by Charles Stross. Basically Stross imagines maths (and hence computer science) as a means of carrying out interactions with other planes of existence (and their inhabitants, who are heavily based on HP Lovecraft's mythos). That leads to maths and engineering as magic, but in-universe it puts the magic on a solid theoretical basis. Bob (the Everyman narrator of most of the series) sums up the situation: something like "I know there's One True God. I know his name, and the ways he can be summoned. And I'll be waiting for him with a shotgun - and saving the last shell for myself." The One True God in this case being Cthulhu. Actual religion relies 100% on the gods and demons not being present in the world. Religion requires belief: proof is antithetical to belief; and hence proof is also antithetical to religion. As Pratchett says, you don't worship a table, because you know it's there. Whilst individual religions may initially turn out to have some neat tricks in the early days, it'll take very little time before this is properly checked out. (Remember we're on a war footing here - wartime science happens *fast*, because it's the difference between survival and death!) If all that's required is True Belief, the logical step is for each person to be instructed to find one thing they truly believe in, and channel that when fighting the demons. Belief in a religion is not required - it could equally well be belief in the superiority of Emacs over Vi, belief in the strength of your relationship, or anything. You can fend off the demons just as well by believing that your dog loves you as believing that God loves you! The Doctor Who series [The Curse of Fenric](https://en.wikipedia.org/wiki/The_Curse_of_Fenric) had exactly this premise as a twist on traditional vampires. The Anglican vicar falls victim to the monsters because he doesn't have enough faith in his religion - but the leader of the Russian commandos is a true believer in communism, so he can repel them using the power of his faith in communism. Similarly the Doctor's companion (Ace) uses her faith in the Doctor, and the Doctor uses his faith in his companions generally (chanting names of past companions). This discovery will greatly weaken religions. To add to their weakness, most people who list themselves as following a religion are not actually True Believers. Religion for most people is actually cultural - your parents did it, so you do it too. So when most religious people turn out to be unable to repel the demons, religions are going to find themselves with a real problem, the same way as anyone who claims to have a vaccine and then discovers it's got a success rate below 50%. And to further weaken religions, how far you happen to be up your religion's structure is no reflection of belief in your religion - consider Jim Bakker, for example. Previously there was no way of testing how much anyone actually believed in their religion, but repelling demons provides a measurable test of belief. When a lot of leading figures in the various world religions get eaten by demons, that's going to be a pretty high-profile set of failures. (Ironically Jim Bakker's belief in the gullibility of his flock may have been strong enough to get him through! But I digress.) So ultimately I can't see any of this being a good thing for organised religions. The existence of demons will be as real as the existence of sharks or lions, and defence against them will be just as real as shark nets or rifles. Calling on any particular religion is unnecessary - and not only that, failed attempts to call on a religion will show up how little strength they actually have. [Answer] This answer ignores the idea that the demons are banished because they are in league with the church and trying to boost attendence. If the demons are genuinely banished by "any old prayer", then there must be a part of the prayer that *actually works*. The most likely reason they work, is because they have a real working component and demons have come to our world before; prayers are simply ancient science from when people were plagued by demons before, carried over through centuries of history. (while adding in a bunch of other myths and nonsense; or maybe the other myths and nonsense are also just dormant today for some reason, like demons were until recently?) It would make no sense at all that all these prayers work just randomly when none of these religions have seen a demon before. So what will happen is the following: * A demon will be captured (they are strong, but not unstoppable, so they can be locked up. In a ring of holy ground, if needed * Scientific experiments will be performed on it, until we figure out which part of the religious prayer / true belief is actually affecting them * A minimalist "religion" will be created that allows demons to be banished with minimal belief (should this be required at all; we might also figure out an even easier way to do it) * The church loses its 15 minutes of fame and will return to being what it's always been For the record; this is what humans **always** do when they realize there is something in religion that works. They extract it, they study it and it becomes common knowledge that everyone accepts and no longer has anything to do with religion. Usually these discoveries are in the area of psychology, but there's no reason to believe it will go any different with physical elements. For an example of how this goes, think about Yoga for example. It used to be religious, then we realized it actually does something useful, and now everyone does it with no religious attachment required. [Answer] It all depends on the ability of the church to strengthen the walls between dimension. A continuous flow on demons simply shows that the church cannot stop them, and the idea that holy ground is off limits for the demons is useless: the fact that thieves do not break into police stations does not make you safer at home. [Answer] ## Yes, religion becomes influential temporarily Say a bunch of powerful demon-like creatures appear in the world, causing havoc. People would have all sorts of responses; I'd guess that some would flee into shelters while others would attack the demons with whatever weapons they've got available. And after it becomes apparent that conventional firearms aren't doing the job, the military'll step in - and, given the premise of this question, also fail. Many innocent would die as victims while many noble souls would lose their lives in trying to fend off the demons. Assuming that the demons can rampage unchecked by conventional means, then they do so until they corner a holy figure, say a priest. The priest says his prayers to Almighty God the Father, asking that his sins be forgiven as he makes his peace before the demon slaughters him. Then, seeing some holy water, the priest splashes the demon, only to see - miraculously - the demon recoil in pain. The priest sees their opening, and uses more holy water - chanting the Our Father, and is perhaps joined by others in his perish, 'til, ***poof***, the demon lets loose a howl of pain and disappears. But, the priest isn't a selfish man. God in Heaven has spared his life and shown him the way to save countless innocents. He takes to arms, spreading the word of this discovery - first-responders change tactics to employ Hollywood-style religious exorcisms, and it works! The first demonic assault has been repelled. ### Initial shock & reaction The world was just assaulted by demons! People are scared and searching for answers. How can they keep themselves and their loved ones safe? Oh, religion! Religious sites would become shelters. People who are naturally inclined to serve society as protectors start their religious training, hoping to gain the power to protect others as the holypeople did in the first demonic invasion. Perhaps there are more incidents, and these observations are upheld. ## Thinkers put it together Thinkers, including but not just scientists, start putting together. It's widely observed that there's some sort of relationship between religion and these creatures that appear to be demonic. But, what ***exactly*** is that relationship? * What exactly determines what is and isn't holy ground? * What exactly determines if an exorcism works? * What exactly constitutes a "True Believer"? * What exactly do demons want? The question, as stated, doesn't provide us with exact answers to these questions. But, the in-universe thinkers will seek answers and piece it together. As already observed by other responders on this question, people will then attempt to exploit those rules, whatever they are. For example, if any sort of religion works, people can just create a religion that involves in believing in the idea that demons should go away, and the ritual for exorcism might be saying, in an annoyed tone of voice, *"Ugh! Stop possessing people you stupid demon!"* ## Demons stop being a public danger After a while, thinkers figure out some sufficiently useful defense against demons, and they stop being a problem. Fear subsides, and that temporary social esteem people had for traditional religion declines, a bit. There would still be major questions about why these generic demon-like creatures even cared for the hodge-podge of mutually-contradictory beliefs that Earth's various religions represent, which by itself is a strange thing. Some people might think that you, the author, exist - since, why else would something so stupid dramatic happen without any apparent connection to reality as they've known it? You, the author, would become a plausible physical force in the universe, and people might start to speculate on what weird thing you'll do next to make the story more interesting. ## The research continues While the people of this world have figured out a working defense, researchers will always want to learn more, improve existing solutions, and discover new options. Some will try to optimize whatever solution they've got to make it easier, cheaper, and more reliable. For example, why exactly does holy water hurt them, and what is the minimal quality needed for something to have that property? Others will want to study the demons. What are there? Where were they from? What the heck were their bodies made out of? If captured and contained, could we use the material from their bodies to build new tools? If launched into the sun, would a demon survive there, being constantly blown around by the onslaught of nuclear explosions? What about if thrown into a super-massive black hole? Others would want to study the physics that the demons imply. For example, we don't know how to teleport, but apparently the demons do. How are they doing that? If we could reverse-engineer whatever a demon's body does, we might be able to make teleportation devices, along with all of the insane technologies teleportation would enable. Others would seek to dominate demons. What they want, if they bother to come to Earth in the first place? What do they fear? What set of incentives and threats could you impose upon a demon to force them into obedience? And since demons seem to obey rules from traditional fiction, then can they be controlled through traditional mythic means, e.g. by saying their "true name"? ## End game: New scientific knowledge, advanced technology, and Pok'e'mon So, there was the initial onslaught and panic. Then there was a period of time in which demons were a curiosity to be studied. Now, it's the distant future - demons are old news. They've been around forever, and people know everything about them. Their biology's been reverse-engineered to produce teleportation devices, so people explore the universe, protected by suits of whatever made the demons so resistant to damage. And, somewhere, there're kids playing with Pok'e'balls. Because, a thousand years ago, there was a game called Pok'e'mon, and when people figured out how to control demons, gamers thought it'd be funny to create brightly-color balls that capture demons and force them to fight. Legends say that there are at least 150,000,000 kinds of demons. Wikipedia's got a section where you can add information on the kinds you've collected. [Answer] Basically: Whatever your story requires. Based on your assumptions, an argument can be made that the church becomes very powerful. They provide the sole defenses of humanity against these evils. This would give them immense influence, money, etc. On the other hand, you can also argue that the fact that **any** religious ritual can be used for banishing as long as it satisfies the criteria, it won't take long until an old pagan ritual (Europe was never 100% christianized) or a jewish ritual, or an imported islamic, african or whatever they believed elsewhere - is shown to work just as fine, people would find themselves at a point where the power of the church is demonstrably real, **but so are other powers**, breaking the monopoly of the church. This could conceivably weaken the church politically despite having more actual power (against demons-that-are-now-real). Both could happen, so pick whichever your story needs. [Answer] **The Church Would Lose** The other answers generally assume the Church would become more powerful. However, this assumes that the Church wins. Humans are quite capable of doing evil even without manipulation by supernatural powers. Demons would presumably be quite adept at quietly manipulating humans dark desires towards their ends without the need to do anything overtly demonic. The demons would presumably have had no difficultly taking over the Soviet Union, and Nazi Germany wouldn't be much harder. As other answers mention there are ways of humans detecting demons. However, if demons are repelled by true belief then it is trivial for demons to find the faithful. There is no need for the demons to play their cards openly and let the general population know that they are taking over the world. If they are repelled by someone's faith, they leave them well alone, and just pass their name along to the secret services. Holy ground is no barrier to someone who is just following orders. Would democracies with strong Christian heritage fare much better? Donald Trump was elected despite Pope Francis claiming Trump was not Christian. President-Elect Trump has inherited Obama's massive assassination drone network, Bush's extra-constitutional Guantánamo Bay and a commitment to eliminate religious extremism in the Middle East. Regardless of Trump's actual agenda, if the demons wanted to define all Muslims with true belief as extremists and use the power of the US military to eradicate them, I don't think that there is much the Church could do. [Answer] I guess your asking how much influence the church would have in general society as an institution if demons like you described roamed the land. There are several angles to look at this in, starting with questions like these: **How suscebtible are people to adhere to or join a church society given the circumstances?** I definitely think more people would become a part of a given church if things like demons were manifest and readily known. In general there are a lot of people who irl have a connection to the church in one way or another, wether it be through faith or traditions, like wedding ceremonies, family traditions etc. That tie would've likely translated to a necassary societal bind (much like school, workplace and general law is today), if something like demons would've been roamed the land. In essence Church (as well as Synagogues, Mosques, Temples, maybe even generel libraries, and so forth) would be a necassary institution for most people, in the worldly and much more readily tangible sense, as they're now doing more than "merely" cultivating faith in people, but are actually providing a service which can be readily seen, felt and heard by all people, not only those who believe. The seperation of Church and State, would, for a majority I think, likely be met with the same skepticism as if you thought of seperating police, hospitals or schooling from the State (in their entirety, which is rare to agree with even if you're for a small government). You would likely "belong" to a given Church (or faith society) the same way you belong to a school today. People might generally try to join prestitious Churches within a given faith, and a kind of scholarly and executionary clergy would definitely be ever more present, mingled in with society as a whole instead of being seperate from it. Other people would likely hop to much "freer" and less administrated societies likely still based on some kind of faith or belief. Things like Omnist-societies, New Spiritual-societies, heck even things like Satanist- and Illuinati-like society groups might be risen from people doing a counter-movement. **Which kind of church societies would there be and how would that shape the general society?** As said before, churches would maybe be their own central institutions in midst of society. In general there would likely be a lot of different Church-societies, with a lof of different political programs and agendas, and even more different kind of churches might've sprung up as a result of the Demons' manifestations. In general, you can likely chalk the catholic and protestant churches to have become the strongest churches in the western world. The Catholic church societies would likely implement a stronger presence of ceremonies, rules and general catholic faith-traditions throughout the society that they are a part of. In essence you could take is as an analogue of when the catholic church used to be as influental as the political court, but with a somewhat more modern understanding and consequent implementation. The protestant societies would likely be a bit more apprehensive, although things like church-going, prayer and schooling would be made a part of the norm for most people instead of being more personal. The severity of all of this kinda depends on how severe the Demon-problem is. These ideas are kinda taken in the stongest case. I believe the church would definitely be a part of the political landscape, and would have as much influence as say the army, the education or banking wold have. That being said, it's difficult how manifest demons would shape the churches current faith-traditions. I personaly don't think much would've changed with the current large christian religions, but rather other church-societies and counter-movements would've sprung up. Another things to keep in mind is how the demons would've shaped religions throughout time and how the current religions would've looked as a consequence. I haven't taken that into account, justly because it needs a much more thorough analysis to be done well. TL:DR, The church would be a central institution in society for most people, much like police and schools. Church-traditions would bleed out to the general people, and church would have a strong seat in politics with same influence as other strong institutions. [Answer] **Really strong** And not least because of the demons confirming that religions are real. There are many parameters, but I assume that the existence of demons would not collapse the society; so not a dooms day scenario. What needs to be understood about the demons is that they are pure evil; they will cause destruction for the sake of destruction, they have no similar sense of utility to co-operate with the mankind, there is no political solution to be made with them. To make a scenario where the civilization does not decay, the people must be stronger than the demons. It would probably revive exorcism stronger than ever. The church would get more money directly from the government. Governments would probably revive state churches, because the strong church would be a must have and they need to pay for it. Catholic church would regain again it's Empire with the power of exorcist divisions and a state church status. Powerful churches would probably engage against each other, depending on how much resources the demons are taking. [Answer] No, it would not be powerful at all. "The Church" wouldn't be special at all and effect would show that the truth is something completely different from what is preached in Abrahamic Religions and then there is the fact that people could and would just ask demons what the truth is... Your limitation of "true believer" isn't really important because I'm an atheist but if a demon appeared in front of me I'd believe it in as much as could be said about it and that belief would be true so any "banishment" would be effective. And the Holy ground thing is problematic in that it is just land that someone finds sacred/holy. I as a naturalist find the Earth as a whole sacred and as such no Demon could spawn on Earth. So "The Church" would actually become weaker, not stronger, and the rules would make the entire situation a rather moot situation. [Answer] In this type of world, police is pretty much useless for demonic matters so I would say the church would become very powerful and an indispensable part of the society. They would participate in the organization and defense of entire cities / countries, there would be whole countries controlled by a religion. This would also cause discrepancies and even wars between different countries that claim to have the best religion or the most effective against demons depending on how good each country / religion is in removing demonds from their society. Maybe there would even exist special monk services like the SWAT team but for demonic matters. [Answer] Your question doesn't indicate to what degree the general population is aware that this situation occurs or to what extent the malevolent actions manifest. In current society, the demons could come through a thin veil and the average person may have no idea the mishaps are caused by demonic action because the demons are in diguise as the person they possess, and therefore people simply believe the possessed person does bad things and not the "demon". Even with religions of all kinds telling people the demons exist and how to banish them, the general masses do not truly believe it, and therefore create their own explanation of why the bad things happen. The people who are specially trained to recognize demonic possession activity (the holy leaders of the religions) and some simply very wise or observant lay folks are the only ones who will do the banishing, and you will end up with exactly the amount of church power we see today. The church will have the amount of power given to them by the unknowing who allow belief in their religion to take away malevolent forces from their lives, and the wise observant individuals who recognize the demonic cause of malevolent forces in their lives will banish them on their own, retaining this power for themselves and those in their own circles that they wish to help. The level of demonic activity recognition and banishment can occur most often symbolically (you give the church financial and volunteerism support and it gives you peace of mind and joy if you follow the religion's tenets) or more rarely literally (you explain to the holy person the bad situation and they perform an exorcism or give you the passages to read that will do the same - which in some religions they do free of charge and others there is a fee for this service). The symbolic and literal recognition and banishment can also occur for the self-empowered individuals, just on a smaller scale, such as counseling and advising a desperate friend of a positive action to resolve their situation, or actively praying and specifically commanding the demon to exit the friend's body. Of course, this would happen more often in that individual's own life as it is easiest to recognize a malevalent force in one's own life. The symbolic methods of banishment work without the people believing specifically in a corporeal "demon" because they simply believe in the symbolic name given to the demon (pick a sin/vice: addiction, wrath, selfishness, jealousy, vanity, greed, etc) and they also believe in the method of banishment (insert whatever virtue/good habit the religion in use recommends). The literal methods of banishment work because the world builder says they do. [Answer] It all depends on the intent for your story. 1. You could go one way with established religions becoming more powerful. Since the before paranormal (demons) becomes established now, religions have proof of their validity. Why aren't angels helping us? Simple: Our priests, clerics, druids etc. have the needed power, since there are many many more than angels. This would in effect look more like the presence of religions and clerics in classig high fantasy worlds, e.g. Faerûn from D&D. 2. Since we have proof of the (formerly) paranormal in the form of demons now, scientists will have a field day. This has become a war against demons, the military will fund research and the invasions will be repelled after a short while. Time to show those demons who's the boss. This would probably go more along the lines of [The Salvation War](http://tvtropes.org/pmwiki/pmwiki.php/Literature/TheSalvationWar). [Answer] Since all religions are made up (Heyo! We've got an atheist here!) and the only requirement for banishing the daemons is that one must be a true believer of a religion which has daemons in it and use rituals aimed at banishing daemons, there's really nothing that bars people from making their own religions just to banish the daemons. I could make a religion worshipping a moldy old meatball. This may not sound like a serious religion, but religions can have just about any rules. I make a religion having the rule that true believers must not take the religion too seriously, and voila, we've got a religion in which just about anyone can be a true believer. Really, the requirements for banishing daemons in your universe are so loose that I don't see why a religion is required at all. I see the daemon, I now truly believe in the daemon, I say "daemon, go away" and the daemon is banished because I founded a belief in daemons in a matter of seconds and made a ritual to banish it on the spot. But maybe this is just based on my own views, which don't lend much credit to religions in the first place... I think some of the other answers are saying the same thing, but in more roundabout ways. I wanted to say this in a more direct way. tl;dr: Banishing daemons too easy. No need religion. ]

[Question] [ In a world I am building, I would like to have the moon change color when seen from the planet's surface as it goes through its phases (e.g., the crescent after new moon is blood red, a quarter moon is greenish, and the full moon is white). Is there a scientifically reasonable explanation for this? Assume: * Any known orbital pattern * Any known material properties (but not necessarily an existing material) * The moon appears round when viewed from the planet The ideal solution will be one where the color changes are due to the properties of the moon rather than the properties of the planet. [Answer] Our moon is tidally locked so we only ever see one part of it (one rotation per orbit). But if your moon's rotation was instead matched to the phases then you would see the same part of the moon during each phase. Now you can just have the moon's soil create your desired coloring. You could explain red by way of iron oxide like Mars. Perhaps a (very) large iron asteroid smashed into and covered a small section of the moon which is only visible during the crescent phase. The green could be [Chlorite, Actinolite, or other greenish mineral](https://www.thoughtco.com/green-minerals-examples-1440940) (or even green plants if your moon supports life.) The white could be [Albite](http://gem5.com/stone/3/albite/) or some other mineral (or ice). As the phases progressed each colored area would rotate out of sight. It wouldn't change colors overnight but instead would transition from one color to the next. [Answer] The Moon can appear to be different colors, as seen from Earth: * [**A red, orange, or yellow moon**](http://curious.astro.cornell.edu/about-us/46-our-solar-system/the-moon/observing-the-moon/142-why-are-the-moon-and-sun-sometimes-orange-or-red-beginner) can appear when the moon is near the horizon, and light has to travel through more of the atmosphere, and more light is scattered * [**A blue moon**](http://math.ucr.edu/home/baez/physics/General/BlueSky/blue_sky.html) (not figuratively, literally) can appear if particles of size ~500-800 nm are in the air, scattering red light but not blue light. * [**A red moon**](https://www.timeanddate.com/eclipse/why-does-moon-look-red-lunar-eclipse.html) can appear during totality of a total lunar eclipse, thanks to - you guessed it - scattering. Now, all of these have to do with the properties of Earth's atmosphere, and the [Rayleigh scattering](https://en.wikipedia.org/wiki/Rayleigh_scattering) that happens thanks to it. All of the above colors are possible. You can make conditions more or less favorable by changing the atmosphere - for instance, making it more or less diffuse to achieve redness and blueness in varying capacities. Perhaps outgassing of some sort periodically changes its composition; elemental levels could fluctuate, like methane does on Mars. The alignment with the moon's orbit would be coincidental. [Mad Physicist suggested](https://worldbuilding.stackexchange.com/questions/115109/moon-that-changes-color-with-phase/115111#comment352606_115111) that the moon itself could have an atmosphere. That does seem like a possibility; [our Moon's atmosphere is quite tenuous](https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon), but other natural satellites in the Solar System, like Titan, have much more dense atmospheres. You'd therefore need some set of gases that change over time. This honestly might be preferable to my original scenario involving the planet's atmosphere. Now, a color like green could be achievable with [a certain type of gas cloud](https://worldbuilding.stackexchange.com/a/64347/627). Doubly-ionized oxygen would give off a green tinge; similarly, [$\text{H}\alpha$ is red](https://en.wikipedia.org/wiki/H-alpha) (as are certain nitrogen lines), and shows up in a number of nebulae, often dominating emission. If this sort of gas is periodically accreted and then dissipated on the right timescales, the moon would appear to change color regularly. A [number of different colors](http://www.clarkvision.com/articles/color.of.nebulae.and.interstellar.dust/) are possible: * **Red:** $\text{H}\alpha$ * **Blue:** $\text{H}\alpha$/$\text{H}\beta$/$\text{H}\gamma$, with appropriate dust absorption * **Green:** $[\text{O III}]$ (doubly-ionized hydrogen) * **Pink:** $\text{H}\alpha$/$\text{H}\beta$/$\text{H}\gamma$, with $[\text{O III}]$ or $[\text{S II}]$ * **Orange:** Dust [Answer] The main difference during the various phases of the moon is the relative position with respect to the star and the planet. Coincidentally, there are structures which have angular dependent properties when it comes to interaction with light: [dielectric mirrors](https://en.wikipedia.org/wiki/Dielectric_mirror). > > Dielectric mirrors function based on the interference of light reflected from the different layers of dielectric stack. This is the same principle used in multi-layer anti-reflection coatings, which are dielectric stacks which have been designed to minimize rather than maximize reflectivity. > > > Having a dielectric mirror naturally forming is pretty though, but if the surface of the moon is covered with [opal](https://en.wikipedia.org/wiki/Opal) it can show different color as the angle of incidence of the light changes with the phase. [](https://i.stack.imgur.com/5fJ3r.jpg) > > Precious opal shows a variable interplay of internal colors, and though it is a mineraloid, it has an internal structure. [...] The regularity of the sizes and the packing of these spheres determines the quality of precious opal. Where the distance between the regularly packed planes of spheres is around half the wavelength of a component of visible light, the light of that wavelength may be subject to diffraction from the grating created by the stacked planes. The colors that are observed are determined by the spacing between the planes and the orientation of planes with respect to the incident light. The process can be described by Bragg's law of diffraction. > > > [Answer] The moon is covered with Sun-facing vegetation. Like sunflowers, they track the Sun movement to always face it for maximum efficiency. If this moon, like ours, is tidally locked, maybe the slower Sun apparent movement helped spread this evolution to much of its vegetation. When the moon is full, the planet is nearly between it and the star. As such, the plants are all facing the planet. When the moon is waxing and waning, either side of the plants are facing the planet. The East and West side could even have different coloration. Alternatively, the body of the plants could change color with the passing day. During the first quarter, the plants are seen in the morning. During the last quarter, they are seen in the evening. (Or vice-versa, depending on the moon's direction of rotation.) For example, if they are ephemeral plants living only one day, in the evening they could be dried up, like leaves in autumn. The moon is too far away for the individual plants to be seen, but if dense enough, the plants could color its surface. Think about a field of sunflowers as seen from afar, east of you. As each sunflower tracks the Sun, you may see the field as a big patch of green in the morning, and a big patch of yellow in the evening as they track the Sun that is now behind you. [Answer] **Seasons.** What are the phases? They are the seasons of a moon. The phases track one circuit around its planet, just as the Earth's seasons track one circuit around the sun. The color of the Earth can change with seasons. [](https://i.stack.imgur.com/loIFZ.jpg) <https://i.stack.imgur.com/46qDx.jpg> So too your moon. Your moon is a meadow, or a forest. It makes sense that for a moon with plant life, the plant life would begin to grow with the coming of the sun (the waxing moon), bloom in the summer of full moon, then yellow and die with the autumn of the waning moon. Spring (green, if you like) would travel across the moon with the leading edge of the sun, with the color of summer in its wake. The full moon would be all the color of summer with edges of spring and fall. As the summer faded the color of autumn would precede winter's shadow. I can see this in my mind but I lack the photoshop skills to do it justice. Anyone interested - please feel free to addend this idea with your rendition of the moon's seasons. [Answer] In theory, if your moon was surfaced with an iridescent material - one that reflects different colors in different directions - the natural libration in its orbit would present varying angles to the surface over the course of its phases. If you took a hunk of moon rock from this moon in your hand and turned it around, you would see the different colors resulting from it. "How" is a bit of a stumper, though; iridescent minerals exist, but not generally in such large quantities, you'd have to have a fairly smooth and regular surface, and in general the arrangement would need to be just so. My first assumption would be "ancient alien art exhibit". [Answer] This is a bit silly, but: if the moon is artificial, it could have ridges along lines of longitude, painted in contrasting colors on their east and west slopes. [Answer] Your material properties assumption is what I would go with. The moon could be made of a substance that reflects light in different ways based on how much of it is reflecting light or absorbing solar radiation. Small amounts of radiation could cause it to be red when slightly exposed, green when quarter, whatever else at other phases, and fully white when reflecting or exposed to all of the sun. This opens up options for the people in your planet to have religious ceremonies using rare deposits of the same material composing the moon found on their planet. I don't know what sort of story you're writing, but I've already got one in my head about people worshipping a lunar deity who demands certain things during each colored phase and using those rocks as if they were pieces of the god. [Answer] Possibility One: The moon could be made of material whose chemical and/or physical structure gives it a different color when illuminated at different angles. If the moon is approximately spherical and one side faces the planet at all times, then sunlight will hit different regions of the planet at different angles at the same time. Thus at full moon, when the moon was on the opposite side of the planet from the sun, the entire planet facing side would also be facing the sun, and it would all be illuminated by the sun. The moon would show concentric areas of different colors or shades, going from the center that was directly pointed at the sun to areas that were slanted away from the sun and had different shades or colors out to the outermost limb of the moon which would be tilted almost perpendicular to the sun. At new moon, when the moon was passing lose by the sun during the daytime, it would be lit totally by planet light reflected from the planet. And the moon would be brightest at the point facing directly toward the planet, and get dimmer in regions farther away toward the limbs. Since the sunlight reflected from the planet would probably be much differ than the direct sunlight, the parts of the moon might lit by the reflected light might be too dim to show colors, and the sunlight reflected from the planet might have the color of the planet. And when the moon was a little bit away from the new phase there would be a thin bright crescent on the side facing the sun, that would be much brighter than the rest of the moon and all one color. And you can figure out how the phases in between new and full would look, I guess. Of course, the moon will only look one single color when it is in a narrow crescent phase. When it is closer to full it should show concentric bands of different colors. One solution might be that the atmosphere of the planet usually contains particles of light or dust that make it very hazy. If the moon appears smaller than Earth's moon as seen from the planet, and if the atmosphere is very hazy, the colors of the different sections of the moon might blend together in one color. When the moon is in a narrow crescent it might only reflect red light and appear red, when the moon is full it might reflect light of all colors from different sections which might be blended together by the atmosphere to look white (also the moon might look so bright when full that the colors can't be detected by the natives and it appears white), and in between it might look like some different color overall. And maybe when the atmosphere is exceptionally clear telescopes might clearly show the different colored regions of the moon. Possibility Two: Long ago, super powerful aliens (or a previous fallen highly advanced civilization on that planet) colored the moon in broad bands. They might have deposited colored materials in broad zones across the moon. Perhaps each zone went between meridians of longitude that were 30 degrees apart, making six zones across the near side of the moon: red, orange, yellow, green, blue, purple. So as the moon goes through different phases the colors of the brightly lit regions of the moon would be: 1) Red. 2) Red & orange. 3) Red & orange & yellow. 4) Red & orange & yellow & green. 5) Red & orange & yellow & green & blue. 6) Red & orange & yellow & green & blue & purple. 7) Orange & yellow & green & blue & purple. 8) Yellow & green & blue & purple. 9) Green & blue & purple. 10) Blue & purple. 11) Purple. Thus the moon of the planet will appear to change color with various phases. Of course it will only appear a single color when it is a very narrow crescent. When it is fuller it will show bands of color. If the moon has a much smaller apparent diameter when seen from the planet than the Moon has from Earth, the bands of color might seem to blend together as seen from the planet. And if the atmosphere of the planet is usually very hazy it may usually blend the colors of the different regions of the moon together. So as the moon goes through various phases it may seem red at first crescent form when only the red region is illuminated; orange when half full and the red, orange, and yellow regions are illuminated; white when it is full and all regions are illuminated and all the colors blend together to make white; blue when half full and and the green, blue, and purple regions are illuminated, and purple when crescent and only the purple region is illuminated. Of course if the bands are laid out and colored differently the moon might have different colors in its different phases. And maybe when the atmosphere is exceptionally clear telescopes might clearly show the different colored regions of the moon. [Answer] Perhaps the moon is a crystal of sufficient clarity that it acts as a prism. Then the earth would drift through different bands of the visible (and invisible?) spectrum as the moon moves around the earth. This might make for interesting near and actual eclipses too. [Answer] When the phases of the moon changes, we still see the same region of the Moon, just with the light coming at different angles. So you need your moon's surface to reflect the light differently at different angles. The surface of the moon is exposed to vacuum and solar wind and micrometeorite erosion, and those will naturally bleach most substances to a dull matte gray (which may appear white when illuminated). So a first thing to note is that **whatever made the moon look like this, it happened recently on a (astro)geological time scale**. A "laser etching" of the moon, something that the planet will have survived thanks to its atmosphere - perhaps caused by a nearby supernova - might have left one half of the moon looking varying in luminosity, but not in color. Or the moon might have been bombarded by [very tiny crystals formed out of a planetary nebula](https://www.nasa.gov/mission_pages/spitzer/news/spitzer-20081111.html). The effect would be slight, but visible on such a scale. Such a bombardment would also probably have caused a nuclear winter on the planet, possibly not so long ago; they might have some wonderful myths about how from the Fimbulwinter emerged a shiny Moon, like a pact from the Gods never to do such a thing again. [Answer] The easy solution (from an orbital-mechanics perspective) is a moon with a rotational period equal to the planet's orbital period. With one side of the moon always facing the sun, and the other always facing away, you'll always see the same part of the moon with each phase. As a side benefit, the extreme temperature differences mean that the color differences could form naturally. Constant solar heating could give a highly-volcanic sunny side, producing a bright yellow surface similar to Io's, while the dark side is a good place for ice to form, giving a highly-reflective surface that appears a dim blue from Earthshine. [Answer] If the moon were a rapidly spinning oblique spheroid with a thick atmosphere and tumbling pole over pole relative to the planet, the light reflected from the moon to the earth would have to travel through more of the moon's atmosphere when it's equator is facing the planet than when the pole is facing the planet. Since the color of the light reaching the planet would be affected by the scattering in the moon's atmosphere you could get a moon that changed color based on the angle between the pole of the moon and the pole of the planet. If the periodicity of the tumbling moon corresponded with the periodicity of the moon's orbit of the planet you could have a moon that changed colors as it changed phase. [Answer] [Luminescence](https://en.wikipedia.org/wiki/Luminescence) could provide an interesting possibility in this case. In the real world the advancing phase of the moon is caused by the moon slowly coming out of the shadow of the Earth. As such the lunar surface soaks up increasing amounts of solar radiation as it's phase progresses. If the source of moonlight is re-emitted rather than reflected radiation it will increase in intensity as exposure time increases. So a lunar surface made up of several different luminescent minerals with differing luminescence thresholds that luminise in different colours will change colour and intensity as it goes through it's different phases. I'm not sure of what mineralogy you'd need but it would probably have to exploit both [Photo-](https://en.wikipedia.org/wiki/Photoluminescence) and [Radio-](https://en.wikipedia.org/wiki/Radioluminescence)luminescence effects to create the exact effect you're looking for. The lunar surface could be any colour including almost black when the sun isn't shining directly on it. ]

[Question] [ I've got a D&D-inspired setting, and one of the races present are yuan-ti. They're sentient snake people with a variety of forms, ranging from mostly human-looking to basically just a giant talking snake, plus a bunch of weird forms like a person with snakes for arms. Status is based on how snake-like they are. I was thinking, they'd probably have snake-like eggs. And it occurred to me that they might be able to use candling (placing a light behind the egg to reveal the contents) to figure out what kind of child they're having. Anyone who knows reptile care better than me able to weigh in? [Answer] Developing comments between @AlexP and me into an answer... As other answers have said, candling of reptilian eggs is possible. For [in ovo testing of chicken sex](https://en.wikipedia.org/wiki/Chick_sexing), if the male and female have different pigmentation or other easily-distinguishable features then this can be highly reliable. There is no reason to think this would be different for reptiles. However, there is an important frame challenge required to this question. The question assumes that genetic randomisation is the dominant feature for reptilian development, and that parents would want to screen their developing eggs for positive/negative features. This is largely true for mammals and birds, because the parent's body keeps the developing embryo at a constant temperature. Reptiles develop differently though, because the majority of reptiles produce eggs which in nature are left to develop on their own. (Exceptions do exist such as the [midwife toad](https://en.wikipedia.org/wiki/Midwife_toad), [some frogs](https://www.bbc.co.uk/news/science-environment-30643756) or [some snakes](https://www.kidzone.ws/lw/snakes/facts09.htm), of course, but the OP's question assumes a species which does not birth live young.) Since the ambient temperature will naturally vary, reptile DNA contains a large amount of "countermeasures" to vary the embryo's developmental pathways and gene expression depending on temperature. The epigenetic effect of ambient temperature is therefore highly significant, to the extent that the embryo's sex can be [dependent primarily on the temperature at which the egg is kept](https://en.wikipedia.org/wiki/Temperature-dependent_sex_determination). For an intelligent species such as the yuan-ti, this has important consequences. It is entirely possible that the physical characteristics of an individual can be predetermined solely by managing the temperature of the egg during development. Humans naturally have not put a great deal of effort into investigating how far this goes, but is likely that intelligent reptiles would have a very long history of discovering what temperature changes at what times during the embryo's development produce what effects - gender as a start, of course, but also physical size and strength, quality of eyesight or hearing, intelligence, or many other possibilities. Candling could be used to screen for developmental abnormalities (embryos which do not look "snaky" enough), but this would be a backup to a much more systematic selection of characteristics for your offspring. As with pre-medicine human midwifery, of course it is quite likely that many of these would be some kind of tribal knowledge. Some may work, some may only work partially, and some may not work at all. But there would still be a body of knowledge which would be called on, and there would likely be individuals who would fulfil a similar advisory role to human midwives, except on a more continuing basis because eggs need longer-term monitoring. So returning to the frame challenge, your yuan-ti parents would not just use candling to "*discover what kind of child they're going to have*" - they would actively choose what kind of child they wanted, and candling would then just be confirmation that development was proceeding as they expected. The implications of this difference for the parents and for the society in general are immense, because this introduces the concept of "designer babies" to a pre-industrial society. [Answer] This is pretty much a let me google that for you kind of Q&A: Reptile eggs can be candled, just like bird eggs. (Probably because, you know, birds are dinosaurs, etc.) Reptile keepers can certainly determine if an egg is viable or not. As with humans and ultrasounds, your sophont reptiles could paint or photograph the resulting images as Junior grows and develops in the egg! And naturally, these pictures can be brought out by a proud Mama when Junior starts courting, much to his own mortification and the eternal delight of his sweetie pie! [Reptile egg candling](http://www.reptilesmagazine.com/Breeding-Lizards/Candling-Eggs/). [Answer] **Let's put some imagination to work** * The shape of the embryo, possibly determining biological sex, but also determining physical abnormalities such as deformed or missing limbs and stunted growth. * Density variations in the shell, possibly showing illness or condition of the mother that can have a consequence for the child or issues that might keep the child from properly hatching. * Density variations in the fluid, possibly showing the development of fungus or bacteria indicating disease or abnormalities in embryonic development. * Color variations in the fluid, possibly showing the presence of blood. Several of those could also be used to identify the presence of parasites, even insects that have bored into the egg and now threaten the child. This kind of information can also lead to diagnoses that include uneven heating during gestation, the need to turn the egg (or not turn it), premature development (egg must be manually hatched early to save the child). Frankly, there's a lot you can do (or could believably do) with candling an egg. [Answer] **Screening for monsters** This is a fantasy. Let us make it fantastic. There are a variety of acceptable Yuan-ti phenotypes. But occasionally something is produced that is really weird; monstrous - unacceptable. Perhaps a Dunwich horror type line with vestiges of other races or even demigods. Shambling many-headed horrors. I envision the candling, and an eye within the egg swivels to look through the shell. Civilized Yuan-ti want no part of such things, and these abominations can prove difficult or dangerous to dispose of after they emerge from the egg. Most are born with abilities that help ensure that they survive. Catching them in the egg before they emerge is a much surer way to prevent their existence. There are correct ways to destroy such an egg; creatures are kept by the Yuan-Ti for this purpose. There may also be those who are interested in hatching and raising these aberrant progeny... [Answer] They could tell if the egg was fertilized and developing normally. They could tell if the embryo died during development, and they'd get a sense when they could no longer see through the egg how long until it hatched. I can't imagine they could tell anything once the embryo fully develops since they'd just fill the egg with their non-transparent body. ]

[Question] [ **Background Details** In this world, a single man (let's call him Morgan) lives in a ginormous steel structure designed to be a perfect model of a small American town. From inside the dome, everything appears to be normal, but once you reach the edge, it is but a wall. This is done so that people from all around the world can watch a sitcom that is real life (think *The Truman Show*). Everything about Morgans life is controlled from his conversations to when his car runs out of gas. **The Question** In *The Truman Show*, Truman only finds out his life is fake because the people running the show mess up: lights fall, rain is isolated, he can tune into their radios from his car. But let's say the people running The Morgan Show are smarter and they don't make the same, obvious mistakes. Assuming that he is content with his current lot in life, how can an ordinary person like Morgan find out that his life is fake? [Answer] The problem made by The Truman show operators was not isolated rain. It is more fundamental than that. As others have said, they taught Truman about the real world, and they taught him about fake worlds on tv shows. Then expected him not to discover that his life was more similar to a fake world than the real one? They taught Truman what a plane was, and then scared him away from using them by saying they are dangerous. Why tell him of the existence of planes in the first place? They taught him that there was a world out there, and built a dome that blocked him off from it. They gave him a tv, so he would be expected to recognise a terrible, overdramatic tv plot - when his uncle twice removed comes back from the dead, claiming to have had amnesia, and actually be the heir to the Morgan family fortune, Morgan will realise that not only is he in a tv show, but the ratings are heading south. TV producers are bad at their job, and he will realise eventually, if he has tv to compare his life to. People are inherently curious. They will explore the limits of their environment. If there is a dome, they will find it. If they have been taught that there is a 'rest of the world' out there, they will realise they are in a 'fake world'. If the Morgan show crew take the same fundamental approach as the Truman show (he knows the world population is ~7 billion, he owns a car and a tv, can afford a plane ticket and reach an airport, and is contained within his world by a dome and 'coincidences' to keep him away from it, He will inevitably try so frequently to leave that the 'coincidences' become obvious conspiracy. If they actually wanted Morgan to never realise he was in a tv show, they would need a much better way to stop him from leaving than relying on him not being curious, and the dome is a liability, not an asset. Base the show in the middle of hostile and remote terrain, i.e. somewhere in Australia, near the border of SA, WA and NT. Don't build a stupid dome. Don't give the town an airport. If he leaves, that's not a problem. Tell both of the people who live within 24 hours drive not to freak out if he talks to them, and if he does drive for 4 days straight to reach Perth, Darwin or Adelaide, plenty of time to drill everyone in 'not messing up a conversation with him', and some time to stage a mugging and some other unpleasant events to make sure he doesn't enjoy his holiday. The best way to stop him realising it is a tv show would be locate the town as above, but don't teach Morgan about the existence of any of the following items: Car, plane, train, T.V., computer, smartphone. This way, if he leaves the town, he will be dying of thirst before he reaches anywhere (and plenty of time for the town to send a rescue team to save him. Have the town mostly self sufficient, and bring in supplies by wagon (well, 99% of the way by truck and the last bit by wagon). This may make the TV show less realistic I suppose? [Answer] **He wouldn't** I enjoyed the Truman Show a lot, but it suffers from a fatal flaw which your scenario shares. We (the audience) see the character's world as mostly normal but not quite right. We know lights don't fall from the sky, people don't blatantly advertise products, and so on. The flaw in the Truman Show is that Truman shares our sense of normality. In actuality, this sense would be shaped by the society he was raised in. Consider the following scenario: Morgan is raised in a village. To our modern knowledge, it is a classical-era European style town. Every day, the High Priest prays to the Great Bird God for benevolence. And each day the Great Bird God (cargo plane) bestows its gifts (paradrops supplies) upon the town. To the outside observer, this is very achronological. But to Morgan, nothing is out of the ordinary. This is the way his world works. The same idea could be applied to the dome. Morgan doesn't think, "This is the dome keeping me from the real world." He thinks, "This is the edge of the world." [Answer] **Alienate viewers and the cast itself by committing serious crimes.** A TV show of this nature will be very skilled at control and manipulation of events. What they’ll have a harder time doing is hiding the fact that Morgan is a criminal or a bloodthirsty psychopath. Even with a heavily cynical perspective of the world today, a show which emphasizes that it’s following an actual person’s life will not be able to depict heinous crimes without consequences. (Most) audiences won’t stand to watch it and real-world laws will require a response. A TV show about Morgan’s daily life in a prison cell is likely to have a steep ratings drop after a couple of days. If the show runners are sufficiently ethically dubious, they might first try to play off the crimes or even hide them. Robbery, vandalism, or even assault could potentially be hand waived with the right PR department (after all, is it really robbery in a fake TV town?). More serious crimes, such as murder, would inevitably have out-of-show consequences that could not be easily hidden. This leads to a choice of cancellation and prison for Morgan (thus having stumbled upon the truth) or doctored footage and an attempt by the show runners to rehabilitate Morgan without his knowledge. Rehabilitation would necessarily require an increase in suspicious occurrences from Morgan’s point of view as his (supposedly) unsuspecting victims somehow seem to know he’s coming or he otherwise has random obstacles thrown in his way. If this continues long enough, even talented show runners might not be able to keep up the farce. This of course says nothing of the cast itself, which might seriously reconsider their roles on the show after the star murders a co-worker. [Answer] **First, he will accept *everything*** As others have mentioned, there's nothing that Morgan wouldn't accept, because he grew up with it. Imagine once a year a bright pink tank drove onto set, shoots massive confetti cannon, then drives off again. Morgan wont think it's weird, he'll just know "Oh, it's that time of the year, the annual pink tank confetti event." **Media** The only way to get Morgan to question his world is to present information about the real world. If he reads books, watches shows, or receives any media that describes the world that doesn't match his dome, then he'll begin to question his environment. Once he's on alert, it will be easier for him to spot discrepancies. [Answer] Travel as far as possible. There's a limit to how big they can make the set. [Answer] **His personality** His personality is probably the biggest thing that can let him know he's in a fake environment. If he's an average joe who will accept life as-is... no. He's not going to find a way out. But that isn't the only type of people that exist. Some have a natural inclination of something more, and follow through with it. Here's some personality types that would "break out of the bubble" so to speak. * **The explorer**. Kys answer makes the claim that he'll reach "the end" and accept it. Someone with a true explorer mentality, when they reach "the end" will try to see what is past "the end". The attitude that looks at "the end" of Europe and says, "I wonder what's on the side of that Ocean..." the attitude that looks at an endless desert and wonders, "Not only can I cross it, but how fast can I cross it?" or the type that looks at the stars, jumps, and then thinks, "Hm... I need to think of a way to get up there" and starts strapping fireworks to the legs of a chair. * **The researcher**. A simulated environment, no matter how well crafted, will have flaws due to limitations of simulation. In fact, there are scientists right now investigating whether *our* universe is one *advanced holodeck* by watching for minute fluctuations in cosmic rays that will indicate if things are truely analog or if they're "rounded" at a certain number of decimal places like a computer might to save space. In your dome scenario, the dome could easily be discovered by tests involving wanting to look at what's "in the sky" by firing some high-altitude fireworks. * **The conquorer**: Someone who rapes/pillages/plunders/conquors/destroys things. Everyone will know what the target of the show would be doing. If he's highly destructive, the world's eventually going to run out of volunteers to take the job. Further, if he ever reaches "the edge", he'd likely try to break it. And he'd get there through conquest. The "fake" world thrust upon him wouldn't matter as he exerts his own will on the world around him. * **The authority**: Someone who rules, who takes command, if he rises up in the ranks (which would be more likely because it'd make good progression) he'd eventually want to contact others and make deals/alliances/etc. Sure, they may all *come to him* initially. Alternatively, if he thinks he's the only one (leader of anything), and that there's nothing beyond, the boundary zone that separates him from the wall will become a terrain to be conquered. it'll be slow, but he'd get his reach to it and through it eventually, or die trying. * **The Thrill Seeker**: Some something "bad" happens every time he heads out into the boundary zone before he hits the wall. Well, that's just an obstacle to overcome. Empty desert? He takes provisions next time. Gas? Next trip he wears a gas mask, takes bottled air, etc. Roving bandits next time? He learns to defend himself next time out. A sea? He learns to sail. Each trip, and each thing that blocks him, he learns to cross it and gets further. The wall at the end of the world? The pickaxe comes out. The fact there are things to block him becomes the very thing that drives him onwards. The fact that the crew will probably avoid killing him will probably drive him to more intense acts of daring-do. [Answer] You couldn't do it with a pretence at reality, ie in a small American town. Curiosity and critical thinking would at some point reveal the truth. He's going to figure out that his life and his town are very different from what he knows about the world. At some point in his life he will want to leave town. There are many reasons why; * He wants to go on holiday * He wants to buy something not available in his town * He wants to have some sort of experience not available in his town * He wants to visit somebody who lives somewhere else An example of his critical thinking might be; My car always runs out of gas. Other cars don't run out of gas. There is something special about me. I don't go on holiday. Other people do go on holidays. There is something special about me. I've seen public transport on TV. There are no trains, buses, boats or planes that leave my town. There is something special about my town. Instead of a setting in a town it would be easier to construct an artificial scenario based around an isolated group of survivors after some sort of global disaster. Examples might be a group in an underground bunker/shelter after nuclear war, or a group hiding on a small isolated island after an alien invasion of the planet. Whatever scenario you come up with you should have; * A backstory to explain the situation and evidence to reinforce it * A physical barrier or obstacle to make it hard to get on or off the set * A compelling reason why nobody would ever try to leave and why nobody ever visits, backed up with evidence of its futility/danger * Self sufficiency, or an irrefutable explanation of resources [Answer] At present, if you wanted to create a 'show' about a person, you actually wouldn't need to confine them in a dome. You could get the majority of your footage from existing sources in our environment - CCTV on the streets, safety cameras on police officers/taxis/buses/etc, you could very easily hide small cameras in objects on his daily routine. Audio could be captured clearly and in real time from his own phone, and he'd be oblivious. That in itself wouldn't make a great show, but we already have shows that make big ratings on low quality footage, pad it out a bit with some opinions of nobodies watching from their couches, a few snazzy graphics, and bam. You have some high-profit low-cost reality TV. Your actor could be anyone, and your show could kick off right now. With the data collection governments are doing, you could spin off hours upon hours of voyeuristic content about almost any person alive and living in a big city that has ample surveillance. The question remains. *How would Morgan find out he is on this show*? Which brings up a poignant answer directly in the comments. *How do you know you're not already on such a show*? Edit: And I feel bad, and should probably give you a hypothetical to go along with your story. Lets assume he never finds out - it's a perfect simulation. But the world grew tired of him, budgets ran out. If this scenario occurred, in a moral world, he'd probably be approached, told that his environment was no longer sustainable and had to leave - hence finding out about the dome. Alternatively, since he is confined in a dome for everyone elses pleasure we can assume it's not a moral world. One day everyone he knows leaves, the world goes dark, and he's alone. You'd either clue on or go mad pretty rapidly. [Answer] I'm not sure how helpful this is but I had an idea I think is intriguing enough to sign up for and share. Do you ever tell someone a story, and when something weird happens, you say it was just like in a soap opera? Well, since he's part of a show this might happen to him. Or his life is so mundane that he gets nuts, starting to question everything, experiencing signs of delusion, developing serious mental illness. As part of said delusion, he becomes convinced that all their lives are staged, resulting in him losing everything. Due to this obsession he starts to find useless proof, tiny tiny holes in the setup that everyone will rule out as complete randomness (This solves the issue of the show's runners being smart enough to not leave any evidence behind) and attribute to his crazyness. Just in the nick of time, before he's locked up for good or something, other people find real proof that they are part of a show. Sort of like in 12 Angry Men, with the protagonist being Juror number 8. Same narrative, make the story about someone in his midlife crisis going nuts, and use this revelation as the ultimate plot twist in the end. [Answer] **Someone from shows crew will tell him** Even if you do something good to people there will be a lot of people that will blame you. In this case you're taking humans freedom so you will have millions of haters. I will be one of them. After few episodes or seasons (and how they will make every season finish on epic moment) someone will get a job at show and then tell him a truth. [Answer] **His life is real.** Influenced and limited but not fake. Observational and perceived reality are relative to the individual and the observer. Yes, he is controlled and influenced directly by others, but we all are. Some more than others. Most people determine and accept their own limiting bubble from experiences and beliefs learned from others. Simply, we create our own domes. Our friends and family add to the dome. Our governments add to the dome. Our memories, desires and fears and create the dome - that does not exist. [Answer] **Probably not at all**. Inspired by @pharap's comment about doubting OUR Sun is real: Our own situation isn't much different from Morgan's. Our ability to test things breaks down very quickly... To what degree would you demand the reality of the Sun proven? Learn optics, astronomy, research possible errors/security flaws in that lore/tech, build (not buy) a good telescope, record from multiple points, [find everything else you don't know about](http://people.sunyit.edu/~steve/sync/idt585-fall2011/data/20110711200400/)... yech. Maybe trust an astronaut instead? But why would you? How would you verify they WERE an astronaut in the first place? Or that they weren't duped? [Going there yourself](https://en.wikipedia.org/wiki/Space_tourism), besides being prohibitively expensive, would have been only marginally better. And then what level of certainty would you say you held if everything you can test checked out, after years of effort? If you were in a world that was NOT modern to the viewers outside, your idea of technical & economical plausibility would be woefully outdated. And, most important of all: What would make you want to go to any of that effort in the first place? The show admins supposedly don't screw up. ]

[Question] [ Are there any kind of contaminants or other reasons that might be dangerous? I'd assume that as far as microbes/bacteria goes, eating off the ground on the moon is much safer than it would be on earth. [Answer] **[Lunar regolith/soil/dust](https://en.wikipedia.org/wiki/Lunar_soil) is probably rather nasty stuff to ingest.** Where the dust on earth has been whirled about in air currents and rounded off, lunar dust is quite sharp and abrasive. It's similar to the difference between pebbles that have been rounded by water in rivers and coastlines, and regular uneroded rocks. This is true even for the finest of particles. If you scroll down to the 'harmful effects' section of the linked wiki page, it details some of the problems if you breathe it in (effects similar to silicosis). While your digestive tract is largely a little sturdier than your lungs when it comes to ingesting stuff you shouldn't, I doubt eating significant quantities of what amounts to glass dust would do you much good. *Edit: turns out it's even nastier!* As @TomášZato mentions in the comments, lunar dust also has a significant amount of unreacted molecules and compounds in it. On earth, these have usually reacted a long time ago and are now inert. Needless to say, ingesting particles of reactive matter is also not recommended. [Answer] **Brush it off, eat it.** Of course there are trace amounts of elements present that are potentially harmful, but the bulk is made up of benign stuff: 50% SiO2, 15% Al2O3, 10% CaO, 10% MgO, 5% TiO2 and 5-15% iron. There will be no microorganisms, no parasites, no viruses, no higher organic poisons. there will be mostly sand-like stuff. About the trace amounts of less cheerful stuff: Consider how much regolith will remain on your dropped sand(ha!)wich - One gram would be much even if you rolled it around in the stuff. Say 1/1000th of that is Chromium (it is not), and pretend all of that then proceeds to villainly oxidise into hexavalent Chromium (the deadly stuff) instead of trivalent Chromium (the vitally important stuff). LD50 for hexavalent Chromium is 50-150 mg/kg ... And you just now ingested .01 mg/kg (if you weigh 100kg). You are safe (but don't make a habit out of it!) The sharp edges of the stuff will not be an issue either: very large shards of freshly broken glass pose a hazard to your digestive tract, but anything on the scale of 'stuff clinging to your sandwich' does not. If you bite off a shard off a glass of water (as children sometimes do) many emergency personnel will only intervene by making them eat some bread afterwards. It all gets buffered by the slime. <http://www.abc.net.au/science/articles/2007/01/18/1828923.htm> Of course it's not Best Practices to eat stuff from the ground, but a little regolith won't hurt. [Answer] It'll break your teeth. The moon is often very cold or very hot on the surface. The sandwich has potentially been flash-frozen or is now burnt depending on where it dropped. ]

[Question] [ We have a professional cartographer, who travels, creates maps, duplicates them, and sells them to people as he travels. Unfortunately, he is not the best at his job - and he has nothing other than a compass, paper, and quill (and ink). I would like his mistakes to be somewhat meaningful - **"meaningful"** defined as: *mistakes which would cost a traveler time in figuring out there was a mistake and in having to figure out the correct action in order to get to where they were intending to go* What accidental (*or on-purpose, but he still intends the map to be useful to anyone who may use it*) mistakes would most affect a traveler who is trying to use the map, yet still seem correct to people who are vaguely familiar with the area? --- As suggested [in the meta question](https://worldbuilding.meta.stackexchange.com/a/2210/2138), the best answer will be the method that is most wrong and least obvious to inhabitants. [Answer] If you look at historic maps (eg. [this map of Europe from 1572](https://commons.wikimedia.org/wiki/File:1572_Europa_Ortelius.A.jpg)), shapes are *locally* accurate and shorter distances are generally correct. However, if you try to combine this local information into a large-area map, small errors in distance and direction add up, giving a distorted overall picture. One way to get this effect is to mix up map projections. For example, you could draw the map using a distance-preserving projection such as [equirectangular](https://en.wikipedia.org/wiki/Equirectangular_projection), then treat it as if it were a conformal (angle-preserving) projection such as [Mercator](https://en.wikipedia.org/wiki/Mercator_projection) or an area-preserving projection such as [Gall-Peters](https://en.wikipedia.org/wiki/Gall%E2%80%93Peters_projection). [Answer] Perhaps his [trap streets](http://en.wikipedia.org/wiki/Trap_street) have gotten away from him. These are intentional errors added by cartographers to prevent someone from copying their work and getting away with it. After all, if everyone described an area perfectly, how could you tell the work apart? If your cartographer is particularly worried about theft he might be letting too many of these intentional fake streets, lakes, or whatever into his maps. Not that accidental mistakes wouldn't exist already with such simple tools. Several mistakes are easy to make: * **[Directions]** The particular cardinal direction a road heads off in (if it gently curves over two miles, that's hard to accurately map without taking a lot of data points). * **[Distance]** How far from the river the fork in the road actually is (without a measuring wheel, all he has is the counting of steps, hard to do in mud or hills) * **[Names]** The name of that small farm he didn't bother to check with the farmer (Old Flabby's Farm might only be what his ex-wife calls the place). Or the river one local has named after himself (Who else can he check with about Bob's River?). * **[Elevation]** Without a reference point or some fairly good measuring equipment he can only estimate elevation by grade/distance measurements or educated guesses (Is that a mountain or a hill?). * **[Math]** Compass measurements and distance alone won't make an accurate map, in order to combine map parts mapped at different times or to accurately judge the length of a curving road, he'll need to do some tricky math without a calculator (Hopefully he's good at trigonometry in his head). [Answer] **He omits details he doesn't think are important.** He's traveled so much that small landmarks no longer impress him. *Surely that pond isn't important. This road might as well not have had a bend there, it gets to the same place. That hill isn't big enough to be worth noting.* [Answer] He could have an iron ring on one hand. Then, as he travels and checks his compass, he could sometimes use that hand to hold his compass. The ring, being magnetic, would make the compass point a different direction, sometimes significantly messing up his map. (This would also happen if there was enough iron (or a magnet) close to him. He could have an iron or magnetic pendant that could also do it.) He could also be making maps in a region with magnetic field perturbations. This would also cause his compass to point in the wrong direction, and would be pretty hard to detect without more advance equipment. (More on magnetic deviation here: [Magnetic deviation](http://en.wikipedia.org/wiki/Magnetic_deviation) ) Lastly, perhaps the area he traveled in could have multiple different measurement standards. Depending on who he talked to, a 'meter' or 'mile' or whatever, could have a few different meanings. If he was a bad cartographer and didn't know this, he could copy maps with differing 'mile' measurements, causing his master map (and any maps copied from it) to be of an inconsistent scale. [Answer] Depending on the era of your setting, over larger distances he might have very great difficulty getting an accurate fix on his longitude. While latitude is easy to measure for anyone who knows how (you need a sextant or astrolabe; no problem for ancient technology), and would allow his maps to be accurate in the north-south axis, longitude requires you to accurately calculate the time in some fashion, which is more difficult for a lone traveller with limited funds if he lives before the era of precision watchmaking. He would need to carry an almanac and measure his position [astronomically](https://en.wikipedia.org/wiki/Lunar_distance_%28navigation%29), which would be potentially expensive and time-consuming, so he can't check it very often. If he loses the almanac to bandits or poor weather or something, his map will suffer a discontinuity until the next town large enough to buy another one, because he won't be able to whip up his own (his observation tools could be replaced by a smith if he has the money, but the tables require advanced astronomy, and that means a city or port). As a result, the maps will potentially be all over the place in the east-west axis, zeroing in on major towns and cities when he gets to them, and distorting by bigger and bigger degrees along the more dangerous or difficult roads. [Answer] Perhaps he never remembers to write down the scale. This would cause mispositioned buildings, longer streets, possibly even disfigured structures if they're large enough. [Answer] Distort the shape of things instead of the scale. This would work best for something other than a road, maybe a river or mountain range. Making them significantly more or less straight can leave out potentially significant amounts of landscape, or create non-existent areas on the map. It's also easy to do when you're not right up on it. [Answer] With the tools you give him (compass basically) you can find directions, but have no sure way to measure distances. So he might be very observant, but over time some mistake may be present. Especially if a travel is more difficult (difficult terrain or weather) the distance might be entered as bigger than it is. Also as a traveller you only see the part around you, setting it all together is extremely difficult without aerial observation. Also in the middle ages scenario people might not be aware about the earth being a sphere and therefore landscape doesn't fit on a plain map without a transformation. All these errors can add up. You can look at historical maps to get an impression:  [Answer] While it doesn't precisely depend on the cartographer's mistakes, environmental changes could lead to his maps becoming outdated/inaccurate. Fires and floods could easily alter, relocate, or entirely destroy things he may have identified as vital landmarks. If the cartographer then returns to such an area (especially if he approaches it from a new direction) he may not even recognize it as the place he mapped and would thus re-map it, assuming it to be a new location near the original one. Combined with some scaling issues, this could lead to the same locale being represented in two wildly different locations on the large map (this also makes the issue his own mistakes rather than uncontrollable, unforeseeable events). [Answer] People tend to make things bigger, more detailed, more prominent, etc. if they are important to them. That's why most maps made in Europe or North America put the Atlantic Ocean at the center, whereas Japan puts the Pacific in center place. Australians put their maps "Upside Down" relative to people in, say, England, where North is up. On older maps, the country of origin of the map maker is usually inflated. Old maps of Europe are notorious for this. Many people make maps to be symbolic rather than functional, which is why older maps sometimes use the "T and O style, where the oceans are a ring, with Europe, Africa, and Asia being separated by a watery "T" representing either different seas or sometimes rivers. Jerusalem is usually centered on these maps, with East on top and Gibraltar (the "Pillars of Heracles") at the bottom. Also, unexplored regions are often completely left off maps, with seas and coasts abruptly ending, usually save for a label, like "Parts Unknown," or in one famous example that's made a definite cultural impression, "HIC SUNT DRACONES." Hope this helps! EDIT: I have been informed that the South-up map orientation isn't as common as I thought! Turns out that's a newer thing. Also, here are some sources for visuals: Inflated Europe: <https://commons.wikimedia.org/wiki/File:Oceanus-hyperboreus.jpg> Centered Japan: <https://brilliantmaps.com/1853-japanese-map-of-the-world/> <https://twitter.com/locmaps/status/1057983596718366720> <https://pasarelapr.com/map/japan-on-a-map-of-the-world.html> T & O: <https://en.wikipedia.org/wiki/T_and_O_map> <https://philosophipotamus.com/maps/map/> Parts Unknown and "HIC SUNT DRACONES" (Note: There is only one known map to have unironically used this phrase): <https://twitter.com/mmoinks/status/990397919915323393> <https://en.wikipedia.org/wiki/Terra_incognita> <https://whereisyvette.com/2014/01/31/maps-from-parts-unknown/> <https://en.wikipedia.org/wiki/Here_be_dragons> [Answer] The map-maker might live in an age where the written language is not very prescriptive. Words and unfamiliar proper nouns ("McLaughlin's farm" could become "Maclaflin's farm") would be written as best the map-maker could understand them, in a sort of personal pidgin. (Or if the map-maker knew the correct spelling, he might corrupt them and simplify them so his intended customers could read them.) [Answer] When making maps or describing routes most things "make sense" if you are familiar with the area or route yourself, but a small discrepancy can mean big differences. If he is making "maps" of routes he has travelled they are not going to be like the kind of triangulated map that we expect, but more likely a long tape with the way points marked, using the compass he should accurately be able to mark which direction people should take. The main thing that would cause discrepancies would be anything obvious to a local. e.g. the map says to follow the road North West from the village past the Millers Family farm and keep going for half a day... etc... At Millers Farm there might be two paths, one that is the correct one and the other that is used by the sheep so seems bigger and better... everyone local knows which one to take and it seemed obvious to your cartographer that the other was to the sheep dip only, so he didn't mark this navigation point. Poor Bill buys the map but he's never been out of the city so doesn't know what a sheep looks like let alone a sheep track... used to travelling on the roads he sees the big track and heads down it... half a day later he's at the sheep dip, not the village; with no idea where he went wrong and no tent... Also changes in the landscape might invalidate his locations/waypoints... that rotten oak might fall completely, that ford could be washed away, but the locals would still know where they had been so wouldn't spot the error Also: Distances might not be measured as distances but in times. I took our man half a day to travel it, but was that half a summer day? How fast did he walk? I imagine [Answer] Historical map inaccuracies often included guesswork that was not clearly marked as such, leading (for instance) to an implication (or even assertion) that one large island was two small islands, or vice versa. A road branching off of his map of the road from A to B might be labelled as going to C just because he knows C is in that direction, even though the road in fact goes around the nearby mountain and then stops at D, which he's never heard of. It also depends how careful he's trying to be. Is he drawing the maps as he goes? Or only at night drawing in the map of the day, in which case he's likely to forget details, or put things in the wrong order? As an exercise, try drawing some maps from memory of trips you take. You'll likely find that you draw roads with fewer bends than they really have, and over-estimate the degree of the bends you do draw. If you draw cross-streets, you'll leave some out or get them in the wrong order; if you try to draw the stoplights and stop signs, you'll probably get some of them wrong. (While he might live in a world without stop signs, he probably lives in a world that care a lot more about the depth and speed of a river or creek that crosses the road.) What sorts of errors accrue, and how significant they are, depend a lot on his intent in these maps. Simplifying out the bends in a road might be completely legitimate, if the point is just to follow the landmarks and turnoffs to get from one city to another when the road is not direct. But forgetting a crossroad or being off by a few degrees will make a huge difference if his instruction is "turn north at the third crossroad". [Answer] Create an accurate, exact map. Describe that map to someone else using words only. Talk for 10 minutes with them drawing the map during that time. Give what they create as the inaccurate map. For less accuracy, take 5 minutes to describe it, and *then* give them 5 minutes to draw it It will introduce many inaccuracies. Many of which are similar to what would exist in inaccurate maps: Placenames can be mispelled. Lengths, areas and positions of features will be innaccurate, less important details will be omitted. Hopefully, these omissions will be worse in areas that are of less importance, as most people will start by drawing the broad land shape and major features/cities, filling in minor features if they have time. Some things will simply be wrong, especially if you use the 2nd suggested method (did he say there was a mountain there, or a volcano??). The two reasons main maps are inaccurate are if the person never saw the features, but is relying on someone else's description, or if they knew, but forgot some or all of the details before they could draw their map - even a rigorous cartographer is unlikely to draw whilst walking. Inaccuracies due to people being bad at drawing, and making things up can also be present, but this method should include the first of those. [Answer] There's a lot to be said for mixing up scale and distance etc... to confuse things but simple count errors with reference to simple landmarks are easy to do and are likely to cause major hassles. To that end mix-and-match the order in which bridges and forks in the road occur, for instance if in reality you cross a bridge and then take the third right to get to Clarke's Crossing then the map should have one of those forks before the bridge and the third right will be miles further down the road and take you to Valport. If you do this with multiple bridges, or other landmarks, and road forks the whole thing will turn into a complete mess very rapidly and working out where you are based on what you have and haven't passed is almost impossible. It's still a rather subtle mess because it's only really in conjunction with directions that it becomes obvious that there's a problem. ]

[Question] [ I'm having a problem, I think, in a world I've built. From [previous questions I've asked here](https://worldbuilding.stackexchange.com/questions/27638/how-might-a-functioning-government-condone-slavery-with-laws-in-place-forbidding), the world is a near to mid-future dystopia of the United States in which the government has collapsed under debt and now functions primarily to transfer the country's wealth to its creditors, and one of the ways it does so is by selling criminals and debtors as slaves, many of them to the upper 0.01% (most of whom hold public office). The 99.99%, therefore, are living in abject poverty by design, as it keeps a fresh supply of criminals and bankruptees coming into the jails (and from there to the auction houses). One of the main characters, after pleading guilty to a crime, lucks out to the equivalent of hitting the Pick 6, and finds themselves living an enslaved life that most people still living free could only dream of. The work's easy (housemaid/servant type work, with plenty of others to share the load since they're not getting paid for it), the living conditions are palatial even by today's middle-class standards, the owner is kind and caring. This is not the norm, to be sure, and the character knows that; other slaves sold alongside the character would have gone to plantations, factories, blood sport arenas, even brothels, and their life expectancy would be months if not days. Here's the main question. Given this situation, what reason, if any, might this character have to want to regain their free status? I can't think of any good reason the character might have to want to go back to the "real world", and in fact I'm considering having this character and other slaves of the same owner fight, even violently, to keep the life they have as slaves against external forces that want to ban slavery as inherently evil, but don't have the financial power to actually improve the lives of the 99.99% beyond that. The follow-up is obvious; is this reversal of the norm for a slave system outwardly plausible, even if I acknowledge the norm exists? This idea of the pretty-much-perfect life gained through slavery is something I can play with as an inversion of the normal 300-style "freedom is worth any price" message, but it's got to be believable, on some level, to be engaging. The challenge the story poses to the audience cannot be suspension of disbelief that a life like this is possible in a slave system, it has to be that they find themselves essentially cheering the character's efforts to stay a slave and working through that cognitive dissonance. [Answer] Take a look at slavery in the Ancient Greece, and in the Roman empire, as it closely matches the scenario you're describing: * Some slaves had it pretty well off, even going as far as having holidays when they went off on their own, etc * Some slaves were treated like animals and died in misery What is interesting in both systems - and particularly regarding the Romans, who had great power to be cruel to their slaves if they so wished - is that if a slave proved himself truly remarkable, then he may not only be set free, but raised in status within society - become a very influential citizen. They would accept this person without looking down on him for his origins as a slave. With such an aim in sight, a slave might aspire to more in life than to be property. However, ***remove that hope***. Give those about to be sentenced some truly horrific choices: if found guilty, of even a small crime, you are shipped off to a terrible penal colony. Your fate there is practically guaranteed death. Optionally, you may choose to become a slave, and take your chances. **But include a catch:** Once you become a slave, even if freed, you may never regain your full rights as a citizen. You will never be accepted back into society; never hold a job again. And as a former slave, you will be doomed to a life of poverty which would make a tramp in today's world look like a king by comparison. As a valuable slave, however, your master may reward you with precious gifts, lavish treatment, and even allow you to start a family. That would work out more or less like what you're asking. [Answer] **Existential Angst** One of the needs for humans described in Maslow's Hierarchy is self-actualization. [](https://i.stack.imgur.com/XQYGq.png) As a slave, this character would not be free to be whatever he feels he must be. A slave can not choose their own path in life. They're restricted to what they're told to do. In the situation you've given, this would not be a very strong compulsion because they've reached a local maximum. They have most of the things they need, but in order to get higher on the hierarchy, they'd need to give up the more important needs already being satisfied. This is likely the same reason many people today work in jobs they hate, because the alternative is (temporarily) much less appealing. --- **Then again, being free requires so much responsibility.** However, it takes an exceptionally enlightened individual to not fool themselves into thinking that the *almost* perfect situation they've got is exactly what they actually want. More likely this character would convince themselves that living a life of service is exactly what fulfills them. They would tell themselves that they'd just be spending the money they earned on exactly the things being provided to them as a slave. They'd think being a slave is more like a job that pays in the goods required for a high quality of life. That they'd never want to leave. Once they're there for long enough they'd become institutionalized; they'd become more comfortable with being a slave than with the responsibility that comes with being free. [Answer] Arguably the same reason some people become entrepreneurs today: **the idea (or fact) of having a boss is itself a negative** quality-of-life issue. There are, arguably, some pretty desirable workplaces out there compared to anything you can easily create as an entrepreneur (Google comes to mind, but there are certainly others); nevertheless, some people leave those workplaces to steer their own endeavors. Not nearly as many as in less-enlightened locales, but still a fair number. In a perhaps overly literal sense, slavery is the extreme case of the "full-time job"; some people will still prefer contract work. [Answer] To answer your first question: The story of [The Dog and the Wolf](http://www.bartleby.com/17/1/28.html) ends with the wolf telling the dog, "Better to starve free than be a fat slave." Of course, the reason the dog's slavery came up at all was the rope marks on his neck - the dog may have gotten free food, but his freedom was curtailed more than the wolf could bear. Slavery usually conjures images of chains, beatings, starvation, isolation, and the complete removal of human rights. In many cultures, slaves were not even considered human. Consider jobs in a capitalist economy; jobs exist with great pay, great benefits, many perks and bonuses, and yet still have a high turnover. Even with the obvious positives, enough negatives exist to push people away from those jobs. There may also be invisible negatives: for instance, a slave that ate nothing but the finest cakes, breads, and beer may be envied by many, but if that slave suffers from Celiac disease, he will be in constant torment, and would much prefer water and dried meat or basic vegetables. To answer your follow-up question, however, in [Rome](https://en.wikipedia.org/wiki/Slavery_in_ancient_Rome) slaves could own land and use it as their own (though it belonged to their master) and earn their own money. Well-regarded slaves were often freed, which meant they were allowed to vote; many freed slaves became highly regarded citizens. In fact, there is such a thing as [voluntary slavery](https://en.wikipedia.org/wiki/Voluntary_slavery) - choosing to be a slave rather than free. It may be that slavery under a good master is preferred to death from starvation with no master. On the other hand, there is always the chance that there are slavers - people actively enslaving the free. In that case, it may be better to choose a master, rather than have one chosen for you. Further, there are workers today that may seem to be in unstable, poorly paid, or even dangerous jobs that nonetheless will staunchly defend their workplace, even working for free to help their company. In the end, it comes down to what the slaves themselves believe; I could easily believe that one slave would take up arms to defend his master and his own slavery to keep even a somewhat comfortable lifestyle, while another slave would try daily to escape from what seems like a life of ease. [Answer] Your protagonist wants to get married. But: * As a slave, your protagonist is not allowed to marry. Or, * As a slave, your protagonist is not allowed to marry a person of that person's class. Or, * Your protagonist is restricted geographically, and literally cannot be with the paramour. Or: Your protagonist is homesick. Or: Your protagonist is heartsick about the evils of the system, and no longer wants to be a part of it. Heinlein's novel *[Farnham's Freehold](http://rads.stackoverflow.com/amzn/click/0671722069)* deals with these themes. [Answer] The situation you describe for the majority of the "free" people doesn't sound very free. The American Declaration of Independence mentions "life, liberty, and the pursuit of happiness" and then says "to secure these rights, governments are instituted among men". And yet in your story, "the government has collapsed". If that is the case, how are rights being secured? It sounds like instead they are being made slaves of a government that captures and sells them at a whim. If the choice is between being a slave to a kind trustworthy master, and being a slave to a mercurial government, then it would seem to make sense to choose the former. However if there is true freedom to be found, then there are several reasons. First, although the master is nice now, how can the slave be sure the master won't betray him, or die and leave him as an inheritance to someone else? Freedom involves risks, but they are risks a man manages himself. As a slave the man is completely in the hands of fate and the whims of his master. Second, there is an intrinsic value in the freedom to change your mind for any reason or no reason and all and do something just because you feel like it. Finally, let me leave you with [this](http://www.johnderbyshire.com/Opinions/Religion/threehistorians.html): The story needs a bit of background. During the first quarter of the fifth century b.c., the new empire of Persia was expanding aggressively under two great kings: Darius, up to 486, and then Xerxes. They wanted to conquer the young Greek city-states, and sent expeditionary forces for that purpose. During one of these forays, the city-state of Sparta had killed some Persian envoys by throwing them into a well. In the years that followed, things did not go well for Sparta, and all kinds of bad omens were observed. The Spartans eventually decided they should make some collective restitution for their crime. They therefore called for patriotic citizens willing to go to Persia and offer their own lives in payment for those of the slain ambassadors. Two well-born young Spartan men, Sperthias and Bulis, volunteered. They set out for Susa, the Persian capital. Persia was a sprawling despotic empire of the pre-modern type. An infallible god-king effected his will through a huge bureaucratic apparatus, the whole thing financed by crushing taxation. ... On their way to Susa the two Spartans — whose selfless mission was well-known, and widely admired — were given hospitality by a high Persian official named Hydarnes. Impressed by these two brave young men, Hydarnes attempted to recruit them into the king's service. "For," he said: "When ye regard me and mine affairs, ye see that the king knoweth how to honour valiant men. Ye also likewise, if ye would give yourselves unto the king, because ye are esteemed of him to be valiant men, might each of you rule over land in Greece, which the king should give you." Then they answered him thus: "Hydarnes, thy counsel as touching us is not evenly weighed. For, of the one thing thou hast made trial, but of the other thou art without experience: what it is to be a bondservant thou knowest full well, but of freedom thou hast never yet made trial, to know whether it be a sweet thing or not. For if ever thou hadst experience thereof, thou wouldest counsel us to fight for it not with spears only but with axes." Thus they answered Hydarnes. [Answer] There's always an uncertainty. Once you become someone's possession you could be sold off at any given time. Today you're living the life, tomorrow you could be in the pits. This risk would normally be perceived as small in the world you describe, because most people don't have the time to worry about the long term. However, if something were to happen to the health or (financial) status of your protagonist's owner/benefactor, the problem would suddenly become more pressing. [Answer] A while back I had to read *Uncle Tom's Cabin* in school. I'd actually really recommend it, because it's a great book, and a really interesting insight into the mentality of Americans before the Civil War. But if you don't want to read it, I've spoiled some of the main points below that you may find useful. What I understood as the central message of the novel is not so much that slavery is bad, or that we should stop having slaves, but instead that humans make for the worst slave owners, and the only good slave owner is God. This message is delivered primarily through the life of the titular Tom. He starts out in Kentucky, which by most accounts seemed to be a nice place for slaves. They were treated nicely, and got along well with their owners. Unfortunately, Tom's owner accumulated some debt, so rather than losing his house he elected to sell Tom and some other slave's infant child. He didn't want to, but he *had to*, or at least that's how he saw it. Tom's next owner was a very laid-back individual who let his slaves do the same things he did, mostly involving lounging around the house not doing work. This again was a good owner, and he saw his slaves as no different than himself, but the fact remained that he owned them. When he died, Tom was again sold away, this time all the way down the Mississippi to the worst of the South. Tom's third owner wanted him to beat other slaves, and when he refused he himself was beaten to death. What I think Harriet Beecher Stowe was trying to do is make good slaveowners feel bad for owning slaves. She realized she could never get through to the racist, inhuman sadists that treated slaves like animals, but by making good slaveowners realize that they could be damning their own beloved slaves in the event of bankruptcy or death, Stowe was probably able to get some slaves freed. Since it was illegal for slaves to learn to read, I don't know if any of them got to read her book, but I'm sure they, too, realized that no matter how good their lives were, they had absolutely no guarantee it would stay that way. Nothing a slave does can secure lasting happiness except freedom. [Answer] From a philosophical point of view, it is always bad to be a slave, and the institution of slavery is always evil. From a practical point of view, given the society being described (or historical societies which practiced slavery), being free but being locked out of the sorts of remunerative occupations that would allow you to survive, you are being asked to trade the philosophical ideal for the reality of either starving to death or being captured by slavers and potentially being sold into a much worse situation. Given the nature of the society you are describing, the only two historical solutions which would seem to have any hope of success would be to raise a slave rebellion (see Spartacus for the Roman example), or to hope an avenging army comes to liberate you (the Boetians liberating the Helots from the Spartans, or the Union armies fighting the Confederacy during the American Civil War). Long range social changes can also take place, where the institution of slavery becomes uneconomical or ethics and morals change again to make the institution of slavery abhorrent to the population (including the elites), but in practical terms, this does not help your character. [Answer] Ignoring issues of personal autarchy, I suspect the reason you're having problems is that your situation doesn't seem to make much sense. If the protagonist "finds themselves living an enslaved life that most people still living free could only dream of.", the question is - why is slavery necessary to fill the jobs? If the conditions are so great, why can't the employer find regular employees? Traditionally, slavery has meant that the slaves don't get paid well and have a noticeably lower standard of living than non-slaves. Either that, or the condition of slavery brings non-economic costs to the slaves: chattel slavery works on the principle that slaves are things, like farm animals, and can be abused or killed with impunity as long as the master's property rights are respected. This generally extends to sexual control as well. Some societies (such as the Romans) have practiced what you might call a restricted form of slavery, and cultural norms may modify the practice of slavery, so you'll have to give some thought to just how slavery works in your society. If conditions in the job are so great, what does the owner get from owning slaves rather than paying less money for the same labor from freemen? That would seem to be the heart of the problem. [Answer] It is interesting in the Old Testament that the ancient Hebrews (after they themselves as a nation had been slaves in Egypt) owned slaves after the Exodus, but if a Hebrew due to debt sold himself into servitude, it was in the form of an endenture so that there was always hope of freedom. A foreign slave could be held for 7 years, but then had to be freed; but it he or she liked the family, there was a ceremony (piercing the ear with an awl on a door-jamb--there was some cultural reason for this, but I forget what) that enabled them to by choice to remain a slave for life. Apparently this was not uncommon! The Jewish religion had strict rules for slave-owners, including giving slaves the sabbath to rest; and being kind to them --this was enlightened for the ancient world. [Answer] > > Is this reversal of the norm for a slave system outwardly plausible, > even if I acknowledge the norm exists? > > > It's plausible, but it relies on the unnecessary generosity of the slave owner. Imagine a coffee shop that pays its staff double what any other coffee shop does. It's completely plausible that this will happen, since coffee shop owners are free to pay their staff what they choose and you are entitled to write whimsical or otherwise abnormal characters. However, this coffee shop needs to compete with other coffee shops, and the owner has to overcome the temptation to hire staff for half as much. Unless there's some tangible benefit in "over-paying" the staff (which this shop discovers and in the long run probably drives up coffee shop wages by discovering it), the market is going to punish the decision somehow. But of course free markets are rife with failed or failing experiments! Your slave's owner is in a similar position: they have to somehow fund their generosity, and they have to be truly committed to it to avoid their standards slipping. Every time they disagree with a slave over something, or they need a bit more space for their books, or have a lot of work that needs doing, what stops them using the whip or making the slaves' quarters less spacious, or increasing their workload? Only their personal belief that they should put their slaves' needs ahead of their own to a certain point. They also need a reason why they're using slaves for this job, instead of getting free people to do it in return for bed and board. Since the slave's situation is preferable to freedom, surely a deal could be done to make the same role attractive to free people but without involving slavery. And if the goal is philanthropy, the slave-owner needs a reason why they're giving a small number of people a large advantage over then norm, in preference to some other arrangement in which they give a larger number of people a smaller advantage over the norm (for example, they could shelter and care for more poor unfortunates by providing slightly less palatial living standards, or they could free their slaves but offer them the choice to stay and work). I'm not saying they should choose differently in order to be plausible, just that the reader needs some idea what their thinking is. [Answer] I've read a few books that have pretty much this exact situation, and they tend to fall into three categories: 1. The slave is the protagonist. Their reasons for wanting to be free are never explicitly stated - they are just assumed, and since no-one in the world of the book ever brings it up or questions it, the reader doesn't either. This is part of suspension of disbelief - sometimes, to get the plot rolling, a character has to do something "just because". 2. The slave is a schemer. They have some sort of plan going on, and are acting politically - for instance, maybe they have been bribed my their masters enemy to escape, so as to embarrass him. Or maybe they just want to make a political point about the ethics of slavery, running away so that the media can print a "slaves are never happy" story. In any case, they want something, and "escaping" is part of getting it. 3. The slave is a supporting character - sidekick or love interest. In this case, they want to be free because they have a connection to the main character, and they value being with them more than their comfortable lifestyle. [Answer] Enough people have focused on the first question. I will apply myself to the second. Yes, it's plausible to have people that prefer slavery to freedom, for a number of reasons. * Some people are honestly wired that way. There are people who just want to belong and be told what to do, and, yes, even to be the at-least-somewhat valued possession of a good owner (with somewhat personalized definitions of "good"). I've met some of them. (note: This is not apologetics for slavery. So far as I'm aware, the vast majority of actual slaves were not like this. I'm just saying that it's a thing that does happen with some people.) * Even for those who don't go that far, there's a strong resonance in loyalty. If the slaves feel that their master actually cares about them and cares for them, then that's the sort of thing that will tend to garner loyalty in return. Having a leader who values you, provides for you, is shielding you from the horrors of the outside world, and just asks reasonable tasks in return? That has some deep resonance in the human animal, at a level that doesn't care all that much about legalistic details. * Even without the above, Stockholm syndrome is a thing. A lot of it depends on treatment - specifically, how the slaves feel the master feels about them, and how much they respect and/or value the master in return. Again, our animals bits don't inherently care about legalities, but they *do* care about human relationships. A life where you are putting total control in the hands of someone who sees you as a disposable thing to be used until it has no further value and then discarded feels very different from one where that same control is put in the hands of someone you can trust to expend effort on your behalf if need be. [Answer] It's quite possible that they would *not* want to become free again. As Samuel pointed out: > > However, it takes an exceptionally enlightened individual to not fool themselves into thinking that the almost perfect situation they've got is exactly what they actually want. More likely this character would convince themselves that living a life of service is exactly what fulfills them. > > > Also, they could realize that they would quite possibly end up a slave again anyway - and in a much different household! - and wisely (?) decide to stay 'enslaved'. [Answer] Suppose your protagonist is a rascal. He likes to gamble (that might be why he fell into slavery in the first place), he likes to experience new things, he is charming and unpredictable. He might get the master's daughter (or wife!) pregnant. He's willing to experience the cushy life for a while, but then he gets bored and wants to move on to a new experience. Imagine Jack Dawson (of the *[Titanic](http://rads.stackoverflow.com/amzn/click/B007SPPANM)* movie) in this situation… what would he do? [Answer] I read the posts before and now. I know I don't have any right to write this but I'd like to tell you some things which may tell you why some slaves or servants want to be free and why some don't want to be free (Warning I'm not shaming the Catholic or Christian religion, I am merely speaking the truth): Perhaps the reason why some slaves want to be free is because they are actually intelligent people and knew staying as slaves would decrease their chances of work or education outside their owner's home. While some owners may use corporal punishments or whips to punish their slaves, if they misbehave. Other owners who are kind wouldn't do it, they don't have the heart to harm another human with less rights. Try to think of it if you were in the slave's position and ended up with an abusive master won't you first feel afraid and attempt to run the first chance you got? To return to your actual home where it is safe and your family is present to take care of you? Unless the owner is actually kind and does not abuse nor misuse his own power over the slave itself. Rather let the slave decide whether he/she would want to continue living in servitute to the master's family. To most people slavery is wrong, but if one were to look at it in a Christian perspective it actually makes a lot of sense. The more you fight for 'freedom' the more the slave or servant rather ends up being hurt, In a worldly manner. However if the servant or slave obeys its Master's bidding then there won't be any problem at all. I should know given that I come from a Catholic family. I won't lie but there were times when my own paternal relatives would abuse their power over me, I tried to fight it but then it got worse and I would probably become bitter, prideful, rebellious and uncaring had I not learned forgiveness, obedience and to be submissive. Even it came with the feeling of fear in my heart not for my own self but for my sibling back then. There's actually freedom in being a servant as long as the person knows who he or she is serving and as long as the master is not abusive. A slave would rather choose that sort of life rather than trying to be independent and able to provide its own needs. ]

[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. Let's say that the world has successfully converted and only depends on renewable resources for our home energy needs. In fact, we have a massive surplus - currently in the form of raw electricity being generated from some science-fiction device. There is a plan being discussed to save this surplus of energy in some form so that it is there if we ever needed it in the future - and so every place on Earth can have a surplus of electricity they can tap into if they desire. Using our current technology, what would be the best way to store this energy according to the considerations below? --- **Considerations:** *Note that they are in order of (most important -> nice to have)* * We are planning very long-term storage. We don't know when, or even if we'll need this storage. * The energy should hopefully require as little effort/tools to make use of it as possible. For the case where there is a sudden disaster, we don't know what kind of tools or processes will still be available. * Size of the storage. In general, we want to use as little space as possible for this huge amount of energy so transportation and storage is easier. * Divisible. It would be ideal to be able to split the energy up if it needed to be. * Cost - The lower, the better, in creation and in maintenance. (*Note that this is least important, but still a factor*) --- To take these considerations into account, it would be best if each answer could have sources for: * Decay Rate (energy loss) of the storage method over time * Basic information on how the raw electricity is manipulated/stored * Basic information on what's required to get the energy out of storage * Efficiency of the energy returned vs. the energy put into creating the storage * Energy Density in terms of volume [Answer] **Use the extra power to convert atmospheric CO2 to hydrocarbons** and store it underground. This offers the long term storage requirements and ease of handling specified in the question. ## **Various Energy Storage Options** * Batteries are known to [lose charge over time](http://www.popularmechanics.com/technology/gadgets/how-to/a7432/why-your-gadgets-batteries-degrade-over-time-6705747/), usually a few years. This isn't long enough. * Capacitors are also known to [slowly](http://electronicdesign.com/analog/whats-all-capacitor-leakage-stuff-anyhow) discharge [over time](https://electronics.stackexchange.com/a/87699/28422). This is a faster process than with batteries. * Fissile materials can't feasibly be made in useful quantities [outside of supernovas](http://www.world-nuclear.org/info/Nuclear-Fuel-Cycle/Uranium-Resources/The-Cosmic-Origins-of-Uranium/). * Fusion materials are [already plentiful](http://fusionforenergy.europa.eu/understandingfusion/merits.aspx) so no storage is needed. * Antimatter tends to bump into things and explode when it does. Not to mention the astronomically high production costs. ## **Benefits of Hydrocarbon Storage** 1. Using the excess energy to remove CO2 from the atmosphere reduces global warming and the associated climate change. 2. The hydrocarbons can be stored at relatively shallow depths this time whereas they were previously available only at great depths at the start of the 21st century. Getting access to them again should be very easy. 3. Humanity already knows how to handle hydrocarbon energy sources. Unless it has been dismantled already, there is considerable infrastructure available for the movement and processing of liquid hydrocarbon fuels. 4. Hydrocarbons are liquids at room temperature and can be stored in plain plastic containers. They are easy to move, store and handle when appropriate safety precautions are followed. 5. These hydrocarbons can also provide [feederstock](http://co2-chemistry.eu/) to the chemicals industry for the creation of all manner of products. 6. Hydrocarbons are stable over million year spans. ## **Considerations:** * Decay Rate: In the absence of an oxidizer or bacterial activity, hydrocarbons don't "break down" as shown by the extreme longevity of deep oil deposits all over the world. The US National Institute of Health performed [experiments](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC169815/) in 1976 to determine conditions for biodegredation of various hydrocarbon fuels. They found significant increases in hydrocarbon-utilizing bacteria in all test plots. Hydrocarbons in the soil were reduced by 48.5 to 90%. * Energy storage/manipulation: Depending on the depth of storage, [simple oil derricks](http://aoghs.org/technology/oil-well-drilling-technology/) can extract the hydrocarbons with metalworking capabilities comparable to Europe/Americas between 1800 and 1850. * Energy extraction: Steam engines or simple atmospheric burning are sufficient to extract energy from hydrocarbons. More advanced boilers or fuel cells permit more efficient energy extraction. * Efficiency of the energy returned vs. the energy put into creating the storage: In terms of processing the atmospheric CO2 into a liquid form and storing it, those energy costs cannot be recovered from the fuel itself (but with the massive surplus described in the OP, this loss isn't a great concern.) However, the energy stored within the chemical bonds of the hydrocarbons don't decay, so future energy consumers will be able to get all that energy back. * Energy Density: The energy density of [hydrocarbon fuels ranges](https://en.wikipedia.org/wiki/Gasoline#Comparison_with_other_fuels) from 19.9 MJ/kg for methanol to ~55 MJ/kg for liquefied natural gas. ## **"Cheating" Answer** Use some/all that excess energy to create the parts required for this science fiction device and store those parts with construction plans in a vault somewhere. If the device is capable of generating that much power, why not just store a copy for use by future civilizations? * Decay Rate (energy loss) of the storage method over time: None as long as the device is undamaged during storage. Assuming geological time scales, someplace like [Yucca Mountain](https://en.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_repository#Geology) could safely store all the components of the science fiction device with low probabilities of damage. * Basic information on how the raw electricity is manipulated/stored: The device doesn't store energy as much as it generates it later. * Basic information on what's required to get the energy out of storage; Please include instructions on how to operate the device. Ideally, the device just has a high voltage outlet and a ground outlet with a big button labeled "Go". Ideally, the device is self-managing so it should "just work". * Efficiency of the energy returned vs. the energy put into creating the storage: Greater than 100% as the energy required to manufacture the device is far far less than the energy the device will eventually generate. * Energy Density in terms of volume: Incredibly high but not infinite [Answer] How's this for an idea. One of the most common elements in the crust is Aluminum. With lots of excess power you could refine massive amounts of aluminum (or maybe other metals such as zinc?) and store them. They could later be used as metal, or to generate power via aluminum-air batteries. In general, electorefining lots of metals could be an excellent way to store energy for long term use. [Answer] The simple answer is - there aren't any ways with current technology. Storing energy is not a simple problem. You can do some pumped storage for example, by moving water from a lake at the bottom of the hill to the top of the hill. Running the water back down through a turbine then generates electricity again. That makes no sense for long term storage though, just wait and rain will fill up the top reservoir. You could split water into hydrogen and oxygen and then store the resulting hydrogen. That would be a fairly dense energy source and you could create sealed chambers underground and just full them with pressurized hydrogen. Hydrogen is a slippery little sucker though and will tend to escape so you'd most likely need to top up the tanks every now and then. To make this easier you could try and generate hydrocarbons rather than hydrogen. Essentially you start creating oil and pumping it back into the earth's crust! [This article](http://www.greentechmedia.com/articles/read/the-long-term-storage-challenge-batteries-not-included) describes some techniques being tried - in particular see the section on exactly this idea. They plan to use electrolysis to create hydrogen and methane and then store it in caverns. They are also looking at Compressed Air Energy Storage and Pumped Hydro in that article, neither really being ideal for long term storage. There is a fairly long list of storage methods on [Wikipedia](http://en.wikipedia.org/wiki/Energy_storage). Just scanning the list you can see that none of these techniques is really suited to long term storage though except for generating hydrocarbons or hydrogen and storing it underground. [Answer] # [Flywheels](http://en.wikipedia.org/wiki/Flywheel_energy_storage) **The method**[[3](http://str.llnl.gov/str/pdfs/04_96.2.pdf)]: * Generate electricity normally. * Use the electricity to accelerate a flywheel to very high speeds. * Capture the kinetic energy of the flywheel when needed. **The benefits** * Essentially no maintenance is required.[[1](http://smartenergy.illinois.edu/pdf/Archive/FlywheelEnergyStorage.pdf)] * The flywheel cannot decay as chemicals in batteries can. While it will eventually spin down due to friction, the timescales of meaningful energy loss are tremendously long.[[1](http://smartenergy.illinois.edu/pdf/Archive/FlywheelEnergyStorage.pdf)] * Flywheels can operate in environments where chemically-dependent apparatuses (e.g. batteries) can not.[[1](http://smartenergy.illinois.edu/pdf/Archive/FlywheelEnergyStorage.pdf)] * Flywheels can be spun up and spun down very quickly.[[2](http://energy.gov/articles/flywheel-project-escalates-grid-efficiency)] * Efficiencies can be higher than 95%.[[3](http://str.llnl.gov/str/pdfs/04_96.2.pdf)] * Flywheels have enormous power density, so you can store more energy in the same amount of space. This also means that they can be easily transported in whatever amount(s) is/are necessary.[[3](http://str.llnl.gov/str/pdfs/04_96.2.pdf)] * Flywheels are incredibly safe, containing no hazardous materials, as batteries do.[[3](http://str.llnl.gov/str/pdfs/04_96.2.pdf)] * Once flywheels are "discharged", they can be "recharged". Here's a breakdown of a typical flywheel: [](https://upload.wikimedia.org/wikipedia/commons/3/34/Example_of_cylindrical_flywheel_rotor_assembly.png) --- There have been some comments about flywheels running down. My response is that all forms of energy storage lose energy over time in some way. Chemicals in batteries can autodischarge, for example. There is no such thing as 100% efficient energy storage over long timescales. [Answer] # Build Solar Panels ... in SPACE Well, when you think about it, no matter what resources we use here on Earth, $\Large\textit{there is this giant}$ $\Large\textit{supersized storage place and}$ $\Large\textit{power station}$ (a large cloud of hydrogen which seems to have caught fire we call the Sun) a few minutes away at the center of our system. Think about it. The [average whole-humanity consumption](http://www.theworldcounts.com/stories/current_world_energy_consumption) is about 16TW (in 2010), while the Sun shines about 174,000 TW on Earth alone, and about 3,846,000,000,000,000 TW more into [empty space each second](http://helios.gsfc.nasa.gov/qa_sun.html#tsi). That's an unimaginable amount of power, and virtually every Joule of it is wasted every second. So the best thing you could do for future generations is to start creating a large and ever expanding cloud of solar panels around the sun, and use *that* surplus to power a space industry to build more and more and more solar capture technology! The technology for creating solar panels [is already with us](https://en.wikipedia.org/wiki/Solar_power_in_the_United_States). Technologies for mining the asteroid belt (for raw materials, to save us the pain of space launches) are [being developed currently by private companies](http://www.planetaryresources.com/) in the Western world. There is nothing technically stopping us from deploying a massive solar array in space, aside from the initial launch costs and the political will to do so. [Space based solar power](https://en.wikipedia.org/wiki/Space-based_solar_power) has numerous advantages over regular solar. It does not take up any valuable ecosystem from the natural wild areas. It does not suffer from intermittent supply due to night or weather. It does not get dusty, for the most part. The power can be transmitted wirelessly ([and has been for decades](http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=1132833)) so with some modifications it could be transmitted from space as well ## Once the 'Dyson' cloud of solar panels is built, store antimatter There are now [considerable technological difficulties](http://home.web.cern.ch/about/engineering/storing-antimatter) with antimatter production & storage, but if the technologies for production and storage can be miniaturized and made significantly more efficient (right now we're producing antimatter by smashing atom beams together -- bit like trying to produce gasoline by shooting cannon into a methane chamber) it could be the most volume- and conversion-ratio-wise efficient form of energy storage we know of in terms of space-ship reaction mass. Furthermore, the construction process for the solar encasement will realistically take a few million years, so that gives ample time for science to advance and better magnetic confinement devices to be devised. Once the Dyson sphere is built, you can store your excess power as antimatter in containment fields, collossal flywheels, whatever. But our descendants will have [zillions of times more power](http://hypertextbook.com/facts/1999/MatthewTsang.shtml) than we did before them. In fact, it's irresponsible not to do it. It's the only way we could have enough power to move out of the Solar system if we decide we don't like it here anymore, or the sun (billions of years from now) goes dark. Storing this energy in space will save you from having to carry this TO space with you. The saying goes that once you're out of the Earth's gravity well, you're energetically speaking halfway to anyplace in the solar system. Moreover, the exercise of building this massive space project will give mankind the much needed practice with building space-habitats and robust space vehicle, something that again you can only learn by being in space, not by saving every little watt on Earth. [Answer] Answering this question is problematic. It's tagged "hard science" but it's worried about the Sun "going out without destroying the Earth" and it wants to do this with "current technology" but for "very long-term storage". The possible time and energy scales are wildly divergent. It's supposed to use current tech and hard science, suggesting a few decades, but they're worried about [the Sun going out... which isn't going to happen for billions of years](https://www.youtube.com/watch?v=yPg2toWfHAU). What time scale are we talking about? A few decades or a few billion years? If the time scale is in the billions of years, the problem is already solved. **The initial gravitational energy of the solar system is stored in a big ball of hydrogen at the center of the solar system, it's slowly being released through nuclear fusion. Mission complete.** --- What about in the short term? How much energy do you want to store? Our [current bulk energy storage can handle about 10^11 Watts](https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity) and [the world uses about 10^16 Watts](https://en.wikipedia.org/wiki/World_energy_consumption). **To store a meaningful amount of energy we've got five orders of magnitude to catch up on**. That's a lot. What would it take? Pumped storage is the most efficient long term energy storage system we have available. You're basically storing gravitational energy by raising water to a high basin. How much would we need to store one year's worth of energy production? 10^16 Watts is 10^16 Joules/second. There's about 10^7 seconds in a year... 10^23 Joules. One Joule is 100 grams raised one meter. [One of the largest existing facilities raises water 380m](https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Station), let's take an average of about 100m. One Joule is 1 gram raised 100 meters. To store 10^23 Joules, one year's supply, at 100 meters and ignoring efficiency loss (it's very efficient, about 80%) we'd need 10^23 grams. There's about 10^24 grams of flowing, fresh water on the Earth (ie. rivers) and we'd need 10% of it. That's a lot, and that's only for a year's worth of our current energy consumption. You could use seawater, but that would increase construction costs and reduce efficiency considerably as places close to the sea tend to not be very high above sea level. You could attempt to use something more dense, but it would need to be easily pumped. The storage plan has problems, and it only holds off the inevitable... **Peak Sunlight!** --- [The Earth receives about 10^17 Watts from the Sun](https://en.wikipedia.org/wiki/Solar_energy#Energy_from_the_Sun). We're already using 10% of that and [world energy demand doubles about every 40 years](https://en.wikipedia.org/wiki/World_energy_consumption#/media/File:World_primary_energy_consumption_in_quadrillion_Btu_by_region.svg). If current trends hold, in a few generations we'll be using more energy than we receive from the Sun. There is only one long term solution... **Become a Type II Civilization** Instead of worrying about *storing energy*, which is hard for the energies and time scales involved, **let's stop wasting so much**. [The Sun outputs a whopping 10^26 Watts](https://en.wikipedia.org/wiki/Orders_of_magnitude_%28energy%29) and the Earth only gets a billionth of that. What a waste! Why worry about squirreling away scraps under the mattress when we could be **gathering a billion times more**? Instead of storing the scant amount of power we're getting, squirreling it away under the mattress, let's use that power to gather more! Invest! **[Make the pie higher](https://www.youtube.com/watch?v=8lYHUQzHfLo)!** Become a [Type II Civilization](https://en.wikipedia.org/wiki/Kardashev_scale#Type.C2.A0II_civilization_methods) that collects all the energy from the Sun, or as much as we can feasibly get. Use energy to build and put satellites into solar orbit to collect solar radiation and beam it back to Earth, eventually forming a [Dyson bubble](https://en.wikipedia.org/wiki/Dyson_sphere#Dyson_bubble) (Dyson Spheres being difficult to build and unstable). Let's do some quick calculations. Now, how fast can we build this sphere? Let's say we can build and launch satellites at a rate which is a percentage of our total power. Need more materials? Use some power to grab an asteroid! This is basically investing in more power generators. We'll benefit from the power of compound interest, more satellites means more power means more satellites! Our principal is the energy received by the Earth and the "interest rate" is how efficient we are at launching satellites. I'll assume we get really good at building and launching satellites so we're pretty much doing it all the time, so we can use the [continuous compound interest formula](https://en.wikipedia.org/wiki/Compound_interest#Continuous_compounding). ``` power production = 10^16W * e ^ (interest * years) ``` Plotting it in Wolfram Alpha shows at [a modest 1% annual increase in energy production means in 240 years we'll be producing 10 times more power than the Earth currently receives](http://www.wolframalpha.com/input/?i=plot+10%5E16+*+e+%5E+%280.01+*+x%29) with power production on an exponential curve towards a Type II civilization in less than 10,000 years. No new science is required, just a lot of practical engineering plus the will and time to do it. Solar panels, solar sails, ion engines, asteroid mining, gravity tractors, microwave and laser energy transmission... these are all current or near-term technology. [Answer] To answer your question, lets actually plan for the final goal. We want to be able to built spaceships that will allow us to evacuate the planet when the current neighborhood becomes undesirable. The only truly heavy lift technology we currently know how to design (in broad strokes at least) is a [pulsed Orion](https://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29) spacecraft. A pulsed Orion drive would work by exploding fission or fusion bombs underneath a pusher plate and is capable of lifting city sized ships into orbit. You need about 800 bombs for low earth Orbit, so lets be conservative and say 2500 bombs for launching a colony ship to Alpha Centauri. The biggest design performed in the original Orion design work would lift 8 million tons, though they considered larger designs they did not flesh out the details. About 20,000 such super Orion ships would be about the right scale to evacuate the earth. So you need about 5 million bombs. Plutonium 239 has a critical mass of 11 kg, so you need 55 million kg of P-239. Half-life of P-239 is only 24,000 thousand years so you actually need to be storing up U-238 which you can then breed in P-239 when you finally need it. So, what you really need is 55 million kg of U-238. Global recoverable resources for uranium are estimated at over 5 million tons. **We don't need to be storing up uranium for future generations.** If we have extra power, we can use it to raise conditions for current inhabitants without worrying about the future needs for escaping the earth. If you are just a prepper at heart, go ahead and refine and stockpile the uranium. However If you really want to plan ahead, build a big space elevator and start moving the population into space, more resources than will even be available when we limit our resources to just this planet. Actually storing up energy for the future generations to abandon earth is a waste of time. Now, let say that we know that people will use up uranium in the interim so we need to create uranium on a large scale using our energy surplus -- don't know why since we a getting all of our energy from renewables. Is such a thing possible? Yes we can transmute lighter elements into uranium by using particle accelerators and proton and/or neutron capture. If you capture excess neutrons, atoms will convert neutrons into protons via beta decay. Neutron capture is much easier since you don't have to overcome electrostatic repulsion of the proton and the atomic core. Thorium is the common element easiest to convert to uranium since it is closest in mass. There is about 4 times as much thorium available as uranium. Still want more uranium, lead is the only other reasonable source elements for uranium breeding that is more common than uranium and thorium as well as being somewhat close to the mass of uranium. But there is probably less than twice as much lead as thorium in the crust and it is much harder to convert into uranium. There is actually a lot more uranium available if you are willing to work harder to get it. Proven uranium mining depends upon current economic viability -- if you are willing to pay a higher cost you could mine a lot more, same goes for thorium and lead too. If you get desperate you could even mine the Moon and Mars for uranium and thorium, as well as the asteroids. [Answer] Someone mentioned hydrocarbon storage. This reminds me of a quote by Feynman from his wonderful [description of Fire](https://www.youtube.com/watch?v=mkqgPDuudUw): > > ...the light and heat that’s coming out [of burning wood] that’s the light and heat of the sun, that went in, so it’s sort of stored sun that’s coming out when you burn a log. > > > If you think about it really hard, wood is merely stored sunlight - literally stored energy. Wood the following advantages: * Wood requires very little effort to use to make fire. We've had the technology to harvest energy from wood from the dawn of civilization. Arguable all that's necessary form extracting fire from wood is knowledge: a wooden rod/dowel to generate heat and wood dust to capture embers. * It is extremely divisible. It's wood after all. * It is fairly cheap. Left alone, it literally creates more of itself. There's one main disadvantage: storage. Wood is fairly inefficient when it comes to energy density. However, wood can be converted to liquid forms for storage: either alcohol or liquefied wood gas (basically methane). Both are comparable to petroleum when it comes to energy density. Storing large amounts of either would give future generations the same sort of energy economy we have today with petroleum. For storing said hydrocarbons (even wood) the ultimate storage would be to bury them deep underground - you'd have practically unlimited space for storage. Future generations would just need to mine them the way we mine petroleum and coal. Of course, for wood all you need to do for storage is to maintain forests. Forests are not the ultimate storage since they take up a lot of space but they're useful as an easily accessible form of energy. The energy stored in forests should be more than enough to be used to mine the stored high density forms of energy. There's a secondary advantage to hydrocarbons: plastic. If not used as an energy source, they can be used to make plastics which will give future generations the same economic boost we had when we discovered plastic. In terms of using said energy for space exploration, both alcohol and methane are viable rocket fuels. In addition, with enough knowledge of chemical engineering, any fuel can be used to generate electricity to power chemical plants to produce more advanced rocket fuels and oxidizers. So, I'd propose the following strategy: 1. Plant more trees and stop destroying forests - forests are the ultimate future resource for future generations. 2. Farm forests in order to convert a percentage of the total number of trees on our planet to high density energy storage: alcohol or methane (or if we really want to push it, even diesel). 3. Store the fuel produced in three stages: the bulk would simply be buried or pumped into mines so that future generations can in turn mine them the way we mine petroleum, a large amount would be stored in tanks in either remote locations or buried underground and lastly keep remainder as living trees in forests. --- Potential problems: While at first glance this seems ideal for solving both long-term energy storage and global warming, doing this at a large scale may have unforseen negative consequences. Firstly carbon, like anything else on our planet, is a limited resource. Just as there's a limit to how much petroleum we can pump out of the ground, there's also a limit to how much carbon we can extract from the atmosphere (which is what planting trees does). Though technically, that limit is probably much higher than the limit we have with petroleum. At the very least we can extract the same amount of carbon we pumped into the atmosphere by burning petroleum. Second, I don't know what would happen if we start sequestering carbon beyond what is natural. Just as releasing carbon into the atmosphere beyond natural levels have significant impact to the environment, so does removing carbon from the atmosphere. I think that at its limits, if we ever reach it, we would have to start managing carbon balance rather than simply burning it like what we do today or storing it as per the plan I've outlined above. It's hard to imagine we'd ever reach this scale of industrialization. But it's not uncommon for sci-fi universes to have industries large enough for this to be an issue. [Answer] Think wider.... think not only "how can we store energy", but also "What would they want to use the energy for?". * Fresh water. Desalination requires energy. Fresh water can be stored indefinitely. * Fertilizers. Making them requires energy. These can be easily stored. * Metals and other base materials. Breaking and refining metals requires lots of energy. Break them now and store them as ingots. Same for other materials that we use in our daily lives. * Hydrogen. Can be used in fuel cells for electricity, for heat, for combustion. Create by electro-hydrolizing sea water, which requires energy. ...and the list goes on. So - again - think wider, not only in terms of storing raw energy only, but also in terms of what we are using the energy for and which of those products are storable. A quick note on hydrocarbon storage: **bad idea**. And anyone that cannot figure out why it is a bad idea should be thoroughly ashamed of themselves for missing the entire climate issue. Let us not repeat nature's mistake by — yet again — making hydrocarbon reserves available for humans to use. [Answer] # Store energy by storing the "how-to-do-it" manual. I know that this is not a popular answer, but maybe your book, or your video or your whatever is documented way to use your fantastic energy source. SAVE your information in a powerful way so that anyone can use it at any time. So, with current technology, the best way to store energy for future generations is not to put it in a battery (or whatever) but to **put it in knowledge on how to refill the battery**. You completed your task with a pen and paper (kind of). Good Q. [Answer] [*Plastics*,](https://youtube.com/watch?v=Dug-G9xVdVs) to appropriate a famous line from a movie. Look at fossil fuel: Lignum was created but nothing could *eat* it. It was the non-biodegradable plastic cup of its day, and it just **piled up** for 50 million years. Vast quantities were buried and taken in by geologic processes, to become coal seams. When fungi finally evolved a way to eat it, the coal beds were already processed by plain heat into nearly pure carbon and also safely out of reach. So our landfills are doing today. Plastic cups and such are not eaten by decay processes, and won't be for thousands if not millions of years. We are already burying the stuff. In 200 to 500 million years it will be coal and deep underground. [Answer] Donald Sadoway's Molten Salt Battery. Donald Sadoway designed and assisted in the construction of protypes of a type of battery for large energy storage based on molten cheap minerals. The structure, as described on the [TEDTalk The missing link to renwable anergy](http://www.ted.com/talks/donald_sadoway_the_missing_link_to_renewable_energy#t-433679) is as follows: --- Low density liquid metal (Magnesium) --- Molten salt --- High density liquid metal (Antimony) --- Further research has introduced the use of other metals. A known drawback of the design is that it relies on stability of the structure to allow the layers of liquid to be maintained. A sudden strong movement of the batteries may cause a short circuit. This means that an earthquake could discharge the batteries, or worse. **Donald Sadoway's explanation**: > > To produce current, Magnesioum loses two electrons to become Magnesioum ion which then migrates across the electrolite and acccepts two electron from the Antimony and then mixes with it to form an alloy. > > > The electrons go to work in the real world (...) powering our devices. > > > Now, to charge the battery we connect a source of electricity - could be something like a wind farm - and them we reverse the current. And this forces the Magnesium to de-alloy and return to the upper electrode restoring the initial constitution of the battery. > > > And the current passage between the electrodes generates enough heat to keep it at temperature. > > > (...) > > > Stacking these (batteries) into modules, aggregating the modules into a giant battery that fits into a 40 foot shipping container for placement in the field. And this has (...) capacity of 2 MWh (...) that's enough energy to meet the daily electrical needs of 2000 american households. > > > --- [Answer] You can create "sitting hydroelectric plants". The idea is to have water reservoirs in high altitude with a connected system to allow slow flow of water down thanks to gravity - opened in case of need. Water would flow down via pipes that conduct water thru turbines to generate electricty. So this is both a source of electricty and water. Recharging means to pump water up. And can be done at a slow rate over time. So this serves as long term storage (req 1) and it is realatively easy to use (req 2). Although it is big (failing req 3) and it is not divisible (failing req 4). The cost of the structure may go down if a good location is found (req 5). Decay happens due to deterioration of the material that holds the water. If there are leaks, water will be lost over time. It maybe possible to allow rain water to enter naturally, but care should be taken to not allow water to avaporate out of the container. Of course, an obviour drawback is that it is taking water out of circualtion. If water treatment improves it is less of a problem, but still it is an added cost to be considered. Edit: I just noticed this solution was dicarded by [another answer](https://worldbuilding.stackexchange.com/a/23125/16729). [Answer] **Warning: This could be considered an answer to a differnt question. I'm aware of that.** It has been [suggested to store generators](https://worldbuilding.stackexchange.com/a/23173/16729) instead of storing energy. I have also [explored the idea of storing potential energy](https://worldbuilding.stackexchange.com/a/32640/16729) - that is: moving stuff up. It is possible to create simple generators that will work by setting them in some relatively high location (such as a branch of a tree) and attach a weigh to them. The generator would allow the weigh to fall slowly, using the motion to generate electricity. This method wouldn't store energy, nor generate large ammounts. But generators of this kind could be done en masse. Of course, the generators would degrade with use, yet it is possible to choose materials that would allow the machine to last for centuries if stored properly (say, in a vault). --- This solution can pass all the requirements: * Requirement 1: It can be stored for a long time, by using slow degrading materials and proper storage conditions. * Requirement 2: It is easy to use, all it requires is to load a weigh, and it would have some energy output to connect an electrical device. * Requirement 3: It is very small - you could have a few in backpack. It can be transported to where it is needed. * Requirement 4: It cannot be divided per se. But the solution is a lot of small devices, spread them as needed. * Requirement 5: Each unit is cheap, although it will be a considerable cost at large scale... yet there is no need to do a single inversion, they can create a few thousand units per month of a long period of time. it is expected that the machines would damage after months (up to a few years) of use. And fail to answer the question: It is not energy storage. --- For a modern real life version of a similar solution - although not to the same problem - see [GarvityLight](http://gravitylight.org/). A solution for increase durability should be possible. [Answer] This is probably stretching the hard science tag, but if you could synthesize heavy elements (uranium & plutonium), you can manufacture fuel for nuclear reactors. Some of those isotopes have extremely long high life and the energy density is tremendous. The problem is that it will probably be complicated to produce the fuel, and to get the energy, you have to operate a nuclear powerplant. [Answer] The best gift we could give to prosperity, as far as their energy needs go, is to develop ways to live prosperous lives that consume even less energy i.e., making things more energy-efficient. As far as storage goes, turning atmospheric CO2 into lumps of carbon is a solution that requires only the know-how of doing it. Elemental carbon doesn't rot (AFAWK), and isn't damaged by anything other than fire. Makes bricks of the stuff and put them someplace out-of-the-way, in small enough quantities that a single fire doesn't take out too much of the supply. [Answer] This is my source: <http://www.rochester.edu/news/show.php?id=2154> <https://www.extremetech.com/extreme/190555-this-nuclear-battery-could-power-your-smartphone-forever-as-long-as-you-dont-value-your-life-or-sperm-count-too-highly> BETAVOLTAIC BATTERIES Similar to the way solar panels work by catching photons from the sun and turning them into current, the science of betavoltaics uses silicon to capture electrons emitted from a radioactive gas, such as tritium, to form a current. As the electrons strike a special pair of layers called a "p-n junction," a current results. What's held these batteries back is the fact that so little current is generated—much less than a conventional solar cell. Part of the problem is that as particles in the tritium gas decay, half of them shoot out in a direction that misses the silicon altogether. It's analogous to the sun's rays pouring down onto the ground, but most of the rays are emitted from the sun in every direction other than at the Earth. Researchers decided that to catch more of the radioactive decay, it would be best not to use a flat collecting surface of silicon, but one with deep pits. So in theory you could store power for as long as the full decay of a radiotactive element, at a low cost, so just get something that has a halflife of a few million years and youre fine. [Answer] To expand on what Serban Tenasa touched on: Build generators. Instead of storing energy you store the means of making energy. ]

[Question] [ You have an advanced space faring civilization tons of resources, and you could build one massive, heavily armored mega ship, or with the same resources, build thousands or hundreds of thousands of smaller ships. And I'd like to look at a gradient here rather than binary: You can obviously divide your resources anywhere between 1 huge ship with all of your resources put into it and an an infinite number of very small ship, so 2 0.5 times ships, 4 0.25 times ships, and so on. How do the pros and cons change as you go down this gradient? Let's assume this is a general purpose military fleet who's opponent is someone with similar capabilities, and the two factions are facing an inevitable all-out war. They can build ships as big as mountains or as small as a manned fighter drone can get. * They aren't interested in smaller unmanned crafts because using AI to control a swarm opens a significant risk of that system being compromised and losing control of their crafts, however they do have a massive personnel force in the hundreds of thousands. * Neither side has developed some massive weapon that the huge ship would have the benefit of carrying. * They're fighting over one small but extremely valuable area. They don't need to span galaxies with their forces. Just one planet of great value to both sides. [Answer] # Redundancy vs. Economy of Scale * A single ship might be more efficient. You need only one person at the helm, etc. You need fewer engineers, physicians, etc. since 'one and a deputy' is often enough. * On the other hand, a single megaship can only be in one place, travel one route. If you never manage to fill her cargo holds and passenger quarters to capacity, they are just wasted. If you have hundreds of smaller ships, you can send just enough for the job. * How efficiently can you load and unload a megaship? Can it land? What is the size of her shuttles? How many can dock at the same time? Space traffic control might become a bottleneck. * Having two or more ships in convoy means that they can help each other if one has an accident, provided that accident is something to hit only one ship at a time. * This applies even more if the attack is intentional. I'm assuming that there is a reasonably portable weapon which can kill the largest megaship. A nuclear missile? If armor helps, things might look different. [Answer] A mega-ship can be in one place. Smaller ships can be deployed to many places at once. In 2017, you don't need a battleship or an aircraft carrier to fight pirates. You need a frigate. Frigates are much cheaper. You can mothball small ships when you no longer need them. You can't mothball half of a mega-ship. When technology improves, you can start making or upgrading smaller ships more quickly than the mega-ship. And while the mega-ship is in the drydock, you have no ship. EDIT 1 - So, what do we do if the pirates in the example above are protected by a heavier ship? What about the frigates then? Well, in our sci-fi universe, it depends upon the technology available Consider the change that occurred in naval warfare in the 30s. Aircraft had improved to the point that one with a crew of three or less could cause severe damage to a capital ship. A small swarm were a danger to any ship afloat. Many things changed about aircraft, but in general they became able to carry heavy ordinance long distances. This was so fundamental that the demonstration the Japanese gave the USA on 12/7/1941 changed how the USA built and organized the entire Navy. In the sci-fi universe, can a frigate or other small ship carry a weapon that can threaten a larger ship? In the Star Trek sort of world, I would not expect a frigate to ever shoot through the Enterprise's shields. In the modern world, the [Russian "Bear" bomber](http://i2.cdn.cnn.com/cnnnext/dam/assets/150129113231-uk-typhoon-russian-bear-bomber-super-169.jpg) is no joke. It will not fly over the USA. Instead, it will stand off the coast and puke out a lot of nuclear-tipped cruise missiles. So again we see weapons that are very portable for the amount damage they do. We need clarification from the OP. But in a universe where nuclear weapons exist (and people will use them) and there are no shields, a larger ship is a liability. EDIT 2 - Modern USN frigates can launch Harpoon missiles. This is really no surprise. This is another modern example of a ship having the ability to destroy a ship that's much larger. Further the frigate should also have smaller weaponry (5", .50 cal, or 20mm cannons) for more tactical use. If we up my arbitrary "frigate" to "destroyer" then all things are possible. But for 2017 pirates, a frigate is enough. For fighting a pirate frigate, it would be my expectation that a government would send six. In an equal-number fight, they'd depend upon superior training, tactics, maintenance, equipment, and discipline to carry the day. EDIT 3 - Regarding *They're fighting over one small but extremely valuable area.*... What's important isn't the size of the area, but how long it takes the ships to traverse an area that size. How do they get to it? How far from the home words is it? Is there a difference in the technology to get to the star system versus the technology required to travel within the system? For our current technology, it could take *years* to get a probe to the outer reaches of our solar system. Even Mars is a few years, I think. This does not make for the best story-telling. In the Honor Harrington books, the author (Weber) addresses this issue by inventing technologies that supports insane amounts of acceleration. And as long as an author is consistent, there's nothing wrong with that. (In one book, HH's poor ancient cruiser is shot up; it takes *weeks* to get to the in-system base... normally it would have taken a day or two tops. Yay math!) Conversely, in the Star Wars universe, ships can travel any distance apparently instantly. Defense is very difficult now. I don't like that model. Star Trek feels very inconsistent to me and I don't pay much attention to any alleged science in the show. The short of it is that you should define how long you want travel to last, and tune your technology capabilities to fit the story. And don't explain why the technology works. A patrol for a USN submarine in WW2 might have been 6 weeks. So if that sounds good, define 3 weeks to go from Earth's average orbit to Neptune's average orbit and call it a fine day! Be sure the time to Mars (a likely stopping point) also fits your story. If it doesn't, fiddle with your technology. (Mars is 1/60th of the distance from Earth to Neptune. So assuming linear time, it would take 8 hours to get to Mars. A WW2 battleship could steam at 20 knots, so that would be 160 miles. Getting from one major station to another major station in 8 hours seems a bit quick. I'd invent a "The engines produce less *magic go fu* when there's more gravity..." Now it might take a week to get to Mars, and 3 weeks to get to the outer reaches. [Answer] The fundamental difference is the surface-to-volume ratio. A big ship has a large volume, which creates a lot of heat (which isn't easy to get rid of in space, an often overlooked pesky detail), but might hold huge reactors or missile stores. A small ship has a relatively larger surface, which enables easier heat shedding, and gives you more space for weapon emplacements. But its armor will probably be a lot flimsier than the megaship's. The crewsize is a matter of technology: it's possible that a highly automated battleship might not need more crew than a fighter. Of course, a fleet of small ships enables different tactics, ie. being in many places at the same time. Whether this is relevant depends on technology and circumstances. [Answer] There is one thing that comes to mind - especially after having read a *LOT* of science fiction based space warfare of one kind or another. Loss of life. Space is a fairly unforgiving stone cold bitch when it comes to space battles/ warfare. Loss of life in a damaged space going vessel is very likely to be total. SO - Pros vs Cons on single large vs many (thousands) of ships. Single large - if the ship is severely damaged - you will very very quickly lose 90% plus of your combatant force. Many small - for each ship that is severely damaged you will still lose 90% plus - BUT there is a high chance you will not have ALL of your fleet damaged/ destroyed. Therefore many small gives you a likely higher survival ratio. Of Course - it will all go very badly pear shaped for the other side whatever ships you have if you have Honor Harrington in your military. Anywhere in your military. :D [Answer] There is a fundamental balance of combat which exists in all renditions of combat. This is just one of them. Many smaller craft offer flexibility, while one larger craft offer strength. If you know *exactly* what needs to be done, and can pinpoint it to a single location, one large craft will give you the most bang for your buck. It can have heavier armor and better weapons. However, in practice war doesn't give you such simple easy situations. Typically an opponent, when faced with one large craft, will make sure there isn't one location where you can just park your ship and win the game. They'll adjust their tactics. They'll make it hard for you to know where to go. They'll have multiple redundant systems. If you have many smaller ships, there are three major advantages. One is that you can spread out across multiple targets. The second is a vast increase in information processing capability. With smaller ships, you literally have a set of eyes on every ship, feeding information back and forth. It is highly likely that someone has seen something that you wouldn't have seen from onboard a monolithic ship. Third, each ship is autonomous. If they see some small goal which they could achieve but you might not be bothered by, they can go get it. While the general is interested in taking a city, the individual grunt can decide "I need to take this room out of this building, because it could be a sniper nest." That sort of distribution is massively valuable. The price of this is that you can't have the arms nor armor that a megaship could. This means that a hardened target may be invincible against your attacks. This is why all real militaries operate on many scales. Navies have ships ranging from aircraft carriers down to frigates, and they use them synergistically. Armies divide up into squads and platoons. They rely on the small flexible units to do the work until the targets choose to harden themselves. Doing so forces them to hold still, which makes them valid targets for the slower lumbering craft or organizations. [Answer] Oversimplifying to the extreme, but you didn't ask for [hard-science]. Larger vessels can support larger weapons, armor, shielding, what–have–you. They are probably also less maneuverable than smaller vessels, even if you had some manner of inertial control which allowed the larger vessel to move about with the same accelerations, relative to an outside observer, as a smaller vessel. A host of smaller vessels are able to do a number of things which larger vessels cannot: * surround the enemy * penetrate blockades * modular — loss of one doesn't impair the intrinsic operability of the others, unless they used some distributed comupting (which, in your case, is unlikely) This one is more of a trade–off with a larger vessel, because your smaller ships are also more likely to be destroyed due to their lack of shielding. * variable spread — the smaller vessels can gather reconnaissance from a wider number of points in their operating theater However, there is that thing with the vulnerability of the smaller vessels. It is quite possible that, because they are unable to support the shielding necessary to adequately mitigate damage, that an attack which would cause no permanent damage to a larger vessel would destroy or incapacitate smaller ones. Smaller vessels may be more difficult to target, but they are easier to destroy. (Of course, that might not be a concern with your world's tech.) That's why most fleets do a little of both. I'd recommend a inverse logarithmic ratio of vessel size to their portion in your fleet: the larger, the fewer. The answer from MolbOrg does a good job too, and probably better. [Answer] It's very much a matter of the technology. In a world where offense beats defense you favor small ships. In a world where defense beats offense you favor big ships. At various times both of these states have existed on Earth. Look back 100 years, battleships. Armor, specifically. Double the diameter, you increase the volume 8x but the surface area 4x, thus you can double the armor thickness. Big enough ships were very hard for the shells of the day to penetrate. Thus the battleship was king. Look at the modern era. The threat is missiles, not guns. Missiles don't have the weight limits of artillery, armor is no longer of value against them. Being bigger no longer is of value in defending yourself. Ships are sized to carry the systems they need to carry, no bigger. That's why the carrier dwarfs it's escorts and why the carrier carries little more than point defense weapons. Also, observe aircraft. Air-to-air aircraft carry no armor at all because it's useless against a missile. Air-to-ground aircraft may carry some armor to help against gunfire from the ground, it's useless against missiles. Thus aircraft are built as small as practical if they're going into harm's way. Bombers are big--but they're also not supposed to be exposed to anything more than light fire from the ground near the target. So long as the missile is king ships will be small. When we move into space the situation might change, though--as the range goes up the missiles need to be bigger and bigger to do the job, missiles to shoot at missiles are far smaller than their targets, eventually the balance would shift back to the big ships. (And it can get even more complex. Observe the Honor Harrington universe by David Weber. At the start you couldn't get a missile through the defenses of a heavy ship. Major battles were ships slugging it out with lasers, armor was of value against this and thus the big ship was king. As the series progresses missiles switch to bomb pumped lasers rather than direct attack--the standoff range makes the defender's situation much harder and the missile comes to dominate. Light ships make a comeback because of this. A while bunch of dispersed firing platforms are more useful than one big ship. They don't replace the big ships, though, because the big ships can actually guide the longer range missiles.) [Answer] It depends on the technologies they have. Different technologies lead to different solutions and different possibilities. The knowing of nuances of those technologies is one of the problems in attempts to figure out the optimal fleet. It starts from ISP of engines they use(or properties of FTL if there is one) to how efficiency weapon can be scaled (bang for energy buck and energy/resource buck to build the thing) As an example Death Star was a crappy ship technology wise, build wise, but it had a good main weapon with good bang for energy buck. But then we also have to understand the goals of the combat, because the destruction of the planets which DS was capable of, it is good and impressive, but what if no one gives a crap about planets as places to live and considering them just as a resource of matter for their constructions. With space habitats, it is a real alternative, and destructions of a planet will make them just happy, as the way which spends them time and efforts to lift the matter from the space body. * yes, in your question they seem to care about the planet, but in which fashion they do that. They will prevent its destruction, prevent a landing of the troops to the planet, prevent nuclear/whatever bombardment, etc. All those and other details are important to answer the question. Another example - if a big ship can wipe a star system in dust in 5 seconds, jump in 5 seconds in any place with FTL and you choose the big one or the fleet of the millions of small ships which are capable(any of them) of destroying the big ship in 5 seconds - go with big one, it will destroy millions of star system before it will be destroyed itself. But if there are countermeasures for FTL - then answer is not so easy, it depends on the efficiency of those countermeasures. If you can see the enemy in FTL, predict his destination, attack while in FTL then the picture is different(and btw similar to the noFTL setting). If we take noFTL setting or one which is just similar, by the properties, to noFTL one, then distributed systems seems to be preferable than a single big ship. Missiles are preferable(but it depends on engines, energy sources, how efficient they really are against the big ship etc) The distribution by size in the fleet depends on goals/task they have to solve and how mass efficient are those solutions. As an example, a carrier in the real world have the displacement of about 100'000 tons but can be destroyed with a single rocket which weight of about 3 tons. If the probability of destruction is 1%, then you better have 1000 of such rockets, it will be just 3% by mass, and the probability of survival for the bigger ship will be about 0.004%. (in real live there will be a problem to launch that many rockets, but in space, you can have them floating, and starting on command; but IRL carrier solves another task of offering different capabilities - that is the part of the task for a fleet problem) But if the efficiency of the bigger ship to be destroyed is not 3% by mass, and you need the same amount(by mass) of rockets, then it might depend on efforts needed to produce those rockets compared to efforts to produce the big ship. Again the AI thing - current rockets do not have AI(as super intelligent thing), they are capable of winning the intelligence race with a rock but that's all they can - still, they are efficient in the destruction of their targets. There are other ways to make them smarter not including AI in the equation, including an operator far far away which chooses the initial strategy of the attack. At some point of nonmagical technology, as far as I can see myself, there is no difference in a big ship or a small ship. You just have more than your opponent and expect that what will be left is that advantage you had, so basically 1:1 ratio by mass. As an attempt to figure things out you might read [the answer](https://worldbuilding.stackexchange.com/a/41407/20315), the OP in the question was more extensive in describing the available technologies, but it still not enough to answer the question.(TL;DR; missiles rocks) Recently I saw a conclusion for [Children of a Dead Earth, game, simulation](http://childrenofadeadearth.com/) that missiles again rocks, but I know a lot of people who will disagree. But the conclusion that missiles rocks, again is not directly applicable to your situation, as it means that big ships might be not the best thing to have, but it does not make small ships automatically better than middle sized. Advances in detection systems play a significant role in the situation but depend on the speed of travel of detected target and the goals it might have. If there is possible some sort of fog of the war situation, then having a fleet of smaller ships can be advantageous to having the big one. etc etc etc etc As a recommendation, go with million or few hundred millions of average size ships(100m - 1km diameter ships). It's adequate force per star system with no defense, which will allow establishing the defense and controlling the system over the time. 10 years and the system will be not easy to take, without magical technologies or overwhelming force. As for a planet, take smaller ships and use them as missiles. [Answer] For a practical answer, there is Eve Online. Eve has served as a test-bed which has shown multiple ideals depending on the opponent and the effective response times of each fleet. Bigger craft require more logistics to get them to field and the turn-around on losses over time can be prohibitive. Really small craft are just unable to bring enough damage to bear on extended engagements. A mix of medium to large (note: not super) with varied damage output brings a much improved tactical response and flexibility. If you do not need to hold the field, such as when the attacker wishes to disperse the standing fleet (such as skirmish actions before the battle) small bombers in sufficient numbers, or a few large ships in hit and run actions. To hold the field, you need to define victory conditions. In Eve, it would be the ones able to consistently replace the losses to keep the damage flowing. Once one side has lost the ability to deal enough damage it has lost, and the field can then be claimed (and looted) by the victor. In a technological space battle, it is thus the missile/ammunition reserves, or the number of pilots, or the raw nano-tech/anti-matter/electro-graft material that determines your ability to keep fighting. One very large ship that serves as a factory base may prove superior to transporting replacement (small) craft [Answer] With the right technology, smaller ships can hit as hard as larger ones by combining their firepower. Here's an example from Star Trek: Voyager: [](https://i.stack.imgur.com/cbxQ6.jpg) In this scene, the formation of 9 identical ships, all relatively small (smaller than the Voyager which is crewed by 150), are generating enough combined power to destroy an entire planet. Larger ships are simply unnecessary. They'll also tend to be slower, easier to hit, and once a critical portion of a large ship is destroyed it's just gone. If one small ship in a megaweapon formation is destroyed, another small ship can take its place. It doesn't even need to be this advanced, either. Firing dozens of smaller missiles or other primitive projectiles can cause as much damage as firing one big one. On the other hand, a larger ship has more room e.g. for a railgun to accelerate a projectile to much higher speeds than smaller ships could. Here's another example from Voyager you might find interesting: [](https://i.stack.imgur.com/wu4LS.jpg) This is called "multi-vector assault mode", in which one large ship splits into multiple smaller craft. This spreads the firepower of one ship across many, allowing them to attack from multiple directions at once. Each ship can move in a different way, allowing all kinds of neat strategies you can't afford when your firepower is concentrated at one location. So, if you can't decide, you could go the "multi-vector" route and make one ship that becomes many when necessary. Best of both worlds, really. [Answer] Really, it depends whether the small ships can carry weapons that are effective against the larger ships. To use a naval parallel, around the turn of the 20th century it was possible to build large battleships such as the *Dreadnought* class that were considered super weapons. The armour on these ships was reasonably effective against anything smaller than the guns carried on large capital ships and the main armament was considered to be lethal to smaller craft. By the 1960s, guided anti-shipping missile technology meant that a relatively small fast attack craft or smaller warship could carry a weapon capable of posing a threat to a capital ship, rendering the large gun systems of early-mid century ships obsolete (the missiles also had greater range). Now there is no need for large gun-armed battleships or heavy cruisers and they are considered obsolete (not to mention the increased role of aircraft from WWII onwards). Thus, there are few weapons that merit building a warship larger than a few thousand tons and larger (cruiser-sized and up) ships are in a minority. The *Ticonderoga* class is unusually large (approx 10,000t) because it carries two very large (~120 tubes in total) vertical launch systems. In most other cases, large naval hulls are built for other payloads (such as aircraft carriers) rather than out of a need to carry a large weapon system. Aside from specialised roles like aircraft carriers or landing ships, surface combatants larger than 5,000 tons or so are unusual. With changing techology the cycle may continue, however, and swing back to large warships being a dominant technology. * Point-defence systems such as Phalanx are reasonably effective at defending against anti-shipping missiles, requiring large salvoes to be launched in saturation attacks. * Lasers can be used to blind pilots or sensors and are potentially an effective anti-aircraft defence, mitigating the current dominance of air power. * Rail gun technology (if it proves effective) fires high-speed kinetic energy rounds with range in the 100's of km that will be difficult to counter with point defence weapons. This could drive a swing back to large, armoured capital ships if these technologies prove to be effective anti-aircraft and anti-missile defence. Then your entry barrier will be a hull large enough to carry a rail gun system and a power plant (possibly nuclear) big enough to power it. So, the answer is - it depends on the capabilities of the technology. In *Star Wars* a few squadrons of small fighters slipped through the defences of a poorly designed super weapon and destroyed it by shooting a torpedo down a reactor exhaust port. In *Star Trek* canon a single Constitution class cruiser was supposed to have enough firepower to trash an entire planet. [Answer] I can't hope to compete with most of the excellent answers here already, but nobody has yet pointed out the issue of artificial gravity. If the contested space is small enough that your craft can launch and return to a planet / moon / space station and the crew only have to endure limited flight times weightless, maybe this doesn't matter. (Although, if the space station is only a short flight away, it will quickly become an obvious target for enemy action, at which point you have to beef up it's armaments so it is basically a mega ship itself). But if any action will require extended periods in freefall, a larger ship is going to be required to spin up to provide centrifugal force, otherwise your crew are quickly going to suffer the medical effects of extended microgravity. (Unless your universe has artificial gravity of course). Radiation is another problem best served by a larger ship. The most effective radiation shield is a thick steel hull, maybe lined with water tanks on the inside. In a small ship, this will take up a much higher portion of your available space and mass due to the lower surface area to volume ratio. You may be able to obtain some charged particle shielding with a strong enough magnetic field (think run donut coils of wire all around the ships hull so that you get a toroidal magnetic field that doesn't permeate the interior volume), but that still benefits from lower relative surface area and probably wants a large power plant to drive. [Answer] A point to consider, military constructions and developments have - historically - resulted in the development of means to counter them. In a purer sense, it's dangerous to put all of your eggs in one basket, even a very safe basket, because somewhere there's a problem solver able to devise a method of defeating your basket's defenses, and before you have time to develop a new defense, your basket's been penetrated and all your eggs absconded with. Historical/allegorical/literary examples? * **Troy** - Trojan Horse. * **The Maginot Line** - Belgium. * **The Whole Egyptian Army** - Paint Cats on your shields. * **13 Ships Hopelessly Outnumbered by the Japanese Navy** - Abuse superior usage of terrain to force a drawn out engagement accentuating the advantages of your superior vessels, resulting in a Japanese rout and a flawless victory. * **The Death Star** - Sabotage * **Scientists Have Revived Modified Dinosaurs Which Pose An Existential Threat to The State of Costa Rica On a Small Island Off the Coast** - Burn it down, burn the whole thing down. The point is, you probably can't build a thing so impressive, dangerous, or resilient that someone else can't invent a creative way of destroying it with a little lateral thinking; this sometimes applies to entire armies, but it's much easier to recover from this kind of thing when your entire military isn't a single massive vessel (or a few of them) - every problem has a solution, redundancy is the same as flexibility here, and is therefore your friend. [Answer] Most of the big points have already been made, but there's a rather large problem with the "Megaship" idea, namely that past a certain size structures start behaving more and more like flexible rods or giant springs. So I'd say the fleet would be a better idea just to avoid having a ship that tears itself apart just trying to accelerate. [Answer] In my opinion, the correct answer would be a little of column A, a little of column B. Larger ships definitely have their advantages. A large ship is usually more efficient in terms of materials and crew. You need skilled crew for every task required and backups for them in case things go pear-shaped for every ship in your fleet. A huge ship doesn't need much more crew for the basic functions (navigation, command, janitorial duties, etc) than a small ship. You need fuel, life-support, water and food for everyone on-board a ship, so less crews and ships means your entire navy is a little cheaper to maintain. Larger ships are also capable of carrying a much heavier compliment of weapons and many more of them to boot. Their size means that energy-based weapons can be used much more effectively since they'll have heavier reactors to draw from. Their added bulk and size means larger weapons platforms can be mounted on them without having to design the entire ship around them. Smaller ships, on the other hand, have other advantages. Individually, they're cheaper, easier to produce (economies of scale begin to apply here) and they're less vulnerable to enemy fire because they are both smaller targets and easier to maneuver (less mass = less inertia = easier to move). Their smaller size necessitates a more efficient design and producing more means that mistakes in the design can be caught in the early models and quickly improved upon. Larger ships do have disadvantages. A single large ship represents a significantly chunk of your planet's GDP and if it runs into an asteriod, rail-gun shot or reactor leak, that is an investment you're never getting back. It paints a huge target on your back and represents a crippling loss to your military power if lost. As an added issue, once your ships get past a certain mass, they actually represent a danger to planets they're orbiting. When you get to Warhammer 40K sized ships, the bulk of the vessel actually becomes a kinetic kill weapon capable of anihilating a planet's biosphere when it crashes into it. That could be a pretty big problem. Small ships aren't without flaw either. A small ship isn't going to have the supplies for long-duration flights. It'll carry a smaller compliment of weapons and said weapons will likely be less powerful. My solution to your problem would be a combined arms approach. Several larger ships would form the bulk of your armada, each representing 5% to 10% of your total fleet's mass. These ships would be a mix between heavy siege ships and carriers. Each one could carry one or several of your heaviest weapons (think along the lines of Spinal Mass Drivers, Exotic Matter Projectors, Wave Motion guns etc). They would also function as supply vessels for your smaller ships. They'd carry extra fuel, food and so on. Naturally, each smaller ship would carry a sufficient amount to get back home but these large ships extend your fleet's operation time by several orders of magnitude. Smaller ships, each around 0.1% and 0.2% of your fleet's total mass would make up the bulk of your fleet in terms of numbers but would ideally represent somewhere near 50% of your fleet in terms of mass. These ships are built for short-term, carrying the minimal ammount of supplies needed for their mission. They carry heavy weapons for their size and much of their mass would be dedicated to ammo, generators for energy-based weapons and so on. These ships would fall into different categories, from bomber-type ships that are a little bulkier and built around their torpedo tubes or rail-weapons. Some would be screening ships, bristling with point-defenses, jammers and sensors. Others would be search-and rescue, carrying emergency repair supplies to help damaged ships limp back to the fleet. [Answer] In real life, your megaship is an aircraft carrier. The carrier can defend itself using guns, torpedoes, and the fighters or bombers on board. Its size makes it less vulnerable to fire from small ships and even if it gets hit, its compartmentalized structure will ensure it doesn't get fatally damaged. Just like the Death Star. Also, its size allows for nuclear propulsion and for carrying a lot of ammunition on board. Without additional protection from a few destroyers, submarines and other smaller ships, the carrier is vulnerable. But, if you judge by the relatively small number of support ships the aircraft carriers had during the [Midway battle](http://totallyhistory.com/battle-of-midway/), it seems, at the time, the carrier was thought as the ultimate weapon. In fact, the battle itself was decided by which side lost more carriers. In conclusion, the megaship should decide a space battle, not so much because it's big and has lots of firepower, but because it is a moving hornet nest, and any attacking ship needs to deal with its fighters. ]

[Question] [ Yes, I know that this is quite a BORING question (get it ;) ), but I really DIG this kinda stuff (no really). If you have watch an action children's show or a cartoon of some kind, we have all seen that moment when they use some large drill to tunnel under the earth or go dig under a wall to get somewhere of some do-thingy like that. In TV-shows etc they usually look like this:  But thing is, I remember that I was quite shocked to learn when growing up that THIS is what REAL bores looked like (and actually they do look quite BORING): [](https://i.stack.imgur.com/9qxFq.jpg) Hey!? What's going on? Is there a physics or engineering (which I presume) reason why we use this big flat bore instead of the pointy one? I was going to use one in my story/short film but I was conflicted — obviously the pointy one is cooler, but it is kinda based on science soo.... In my quick little evaluation it doesn't seem like either is really worse off, except perhaps maybe the pointy one might become dull at the tip, but is that a really big issue, and would it not be prevalent in the flat one too? [Answer] > > Is there a physics or engineering(which i presume) reason why we use > this big flat bore instead of the pointy one? > > > **A minimum area cutting surface is best in hard rock; so disk beats cone.** If memory serves, the flat face of the real tunnel-boring machines is pressed -- with enormous force -- against the rock face, as it rotates. The cutting wheels and teeth generate huge, localized pressures, to fracture away bits of the rock face. The flat, disc face has the minimum area and can be made strong and simply. The real one also has strong hydraulic jacks that grab the already-bored tunnel walls, to ensure that the cutting disc rotates, rather than the body of the machine spinning uselessly. (They also have an impressive system for conveying the ground-up rock, etc. out the back and away.) A grooved, conical, cutting 'nose' as in the illustration might work in soft soil -- if that machine had something to prevent the body from counter-rotating and a means to move the pulverized soil out behind it. [Answer] > > Is there a physics or engineering(which i presume) reason why we use this big flat bore instead of the pointy one? > > > Yes. A bore is essentially a really big drill bit. As such, the shape of the bit is determined by the material you are cutting. The cartoon bore has a twist bit that has a high twist rate resulting in a large surface area for the swarf (the stuff being removed) to pass by. This will result in lots of adhesion and will cause [galling](http://www.twi-global.com/technical-knowledge/faqs/material-faqs/faq-what-is-galling/). Large amounts of lubrication will be required to prevent this: water, oil, etc. anything to keep the rock from sticking to the drill bit. The real-world bore uses a conveyor belt to move the swarf rather than a spiraled groove (which is just an Archimedes Screw). The cartoon bore also has very acute point angle. This is great for drilling through soft materials (clay as James points out), but is terribad at drilling through hard materials like rock. Take a trip to a hardware store and look at the difference between drill bits for wood vs. those for metal or concrete. The angle will determine the surface area faced by the cutting edges, and more surface area equals more friction. Friction creates heat, and heat causes more wear and tear. This will again require more lubrication to draw off that excess heat, but how would you pump all that lubricant to front of a pointy drill bit? So while the cartoony bore *might* work, it would wear out quickly, require more lubrication to prevent galling, and ultimately be much more expensive to run (as Molot points out) because you would constantly be replacing a giant bit. [Answer] First of all in the cartoon one is based on a drill that you use on a soft material that is consistent. Like wood or plexi. The idea behind this is that you have a room for the shavings so they don't block your tunnel (because there is no tunnel) The real one is build to drill through materials of different density at the same time while the shaving can pass inside the drill to get moved on a belt transmission. This design also help cooling the drill while the regular one don't have any cooling. And to point out the obvious thing - the cartoon machine is bigger than the drill so it would be useless. [Answer] Lots of issues here that make flat better than pointy...most of which can actually be boiled down to a single idea... *surface area*. 1. More surface area (a cone) generates more heat. * More heat requires more cooling equipment and more maintenance * More heat reduces the life of the cutting edges... Heat > Steel * More heat is bad for workers underground in a confined space 2. Geologic stability * A cone is going to cause cave-ins more often that the flat guy. The machine (as mentioned elsewhere) is designed to support the weight of the earth it removes until supports can be placed. The cave ins are going to cause you to have to dig, and then re-dig as things fall from above. The only situation where I can see a cone working better would be a situation where for some reason you want to dig a tunnel into clay...but...why would you want to do that? [Answer] The cartoons leave out a very important fact: To make a hole, you have to remove a "hole-shaped" volume of material to some place else. Wood is fibrous, which means it actually contains quite a lot of air spaces, so if you are inserting a fairly small wood screw, you are just squashing those spaces without actually "removing" any of the wood. The fact that the wood is then trying to spring back and fill up the hole improves the grip on the screw. It is much easier to drive a screw into a wood like pine which contains a lot of air space, compared with a something like oak which has less. But to make a larger hole that will stay open on its own, you have to remove the material somehow. The cartoon boring machine doesn't have any way to do that, except by material travelling up the spiral grooves, which inefficient because of the amount of friction between the moving material, the unbored material, and the borer itself. In the real tunneling machine, there are holes in the cutting face along the edges of the cutters, so the cut material can fall through to the *inside* of the machine, and then be removed with the minimum amount of effort so long as you can remove it as fast as you are cutting more material. [Answer] I know this question is more on the physics, but this is the Worldbuilding stack so I want to help you with your writing problem. I recommend looking at how "Avatar the Last Airbender" handled this Issue in the Episode "The Drill" . It is a childrens Cartoon, and their Drill is a mixture of the two. It is almost flat at the front, but still has a little pointyness to it. It looks more menacing then the real one you posted, and is more realistic then the comic one you posted. [](https://i.stack.imgur.com/MjAqs.png) [Answer] If you look at old hand auger bits (as used with a [brace and bit](https://media1.britannica.com/eb-media/18/6818-004-2A591582.jpg)), they had a tapered screw-like thread on the end and then a body with a helical rib. The helical rib was obviously to carry the cuttings away from the work area, and, to the casual observer, the screw-like end did all the cutting. Only on close inspection was it clear that some chisel-like surfaces at the junction between the tip and the spiral were what actually performed the cutting. Even more confusing is a [bung auger](http://i.ebayimg.com/images/g/I1sAAOSw~bFWK~zO/s-l300.jpg), where a short auger bit (of the above style) is combined with a conical wood plane. It is easy to see how a person who did not actually work with such implements would come to believe that the pointy-ended device in the first image would make sense. [Answer] In cartoons they are drilling through 2D ground. It's like piercing paper. You're squeezing the ground sideways rather than around and behind. Therefore they don't have to worry about swarf or friction and the pointier the better as it'll move you forward faster. Depending on the physics of the cartoon universe, the ground may backfill/unsqueeze after you've passed or not. ]

[Question] [ I forgot to charge my time machine and now I'm sitting in medieval Europe and need to recharge the batteries. Luckily, those are only car batteries and not the old plutonium powered ones. What's the easiest way to generate a sufficiently stable voltage/current output to charge my car battery? Assume I can talk to other people and buy what's widely accessible, but if I tell them too much they'll probably burn me as a witch. Bonus question, can I get some kV AC? [Answer] The first piece of good news is that witch burning is much more an [Early Modern phenomenon](https://en.wikipedia.org/wiki/Witch_trials_in_the_early_modern_period) than a Medieval phenomenon. The second piece of good news is that you can pass for a very respectable alchemist, especially if you have a white beard and know how to make simple explosives such as [nitrocellulose](https://en.wikipedia.org/wiki/Nitrocellulose), also known as *gun cotton* (and as *fulmicoton* in French, a splendid name). The third piece of good news is that copper wire was readily available, as were various acids and zinc (available for export in India since the 12th century). Make a number of zinc-carbon cells, connect them in a suitable way (enough parallel rows of 9 or 10 cells each) and charge your lead-acid car battery. Depending on *when exactly* you are stranded, you may have to build the ships to go to India to buy the zinc, but that's a minor consideration. (If you want to get zinc from European sources or if you must wait for Vasco da Gama to open the trade with India then that's the 16th century; as some users here tell me, the tendency nowadays is to consider the Renaissance a major historical period on its own instead of simply the last part of the Middle Ages, so that would be outside the indicated time frame.) For those kilovolts AC you need alternators. Iron is available, copper wire is available, shellac you can buy from India: you are all set. By the way, you have advanced the knowledge of explosives, of electrochemistry and of electricty in general by several centuries. You may have also brought the Age of Discovery a few centuries before its time. The world you will return to won't be the world from where you started your journey. [Answer] Fortunately you already have an AC generator built into your car, the [alternator](https://en.wikipedia.org/wiki/Alternator_(automotive)). All you need to do is turn it fast enough to generate electricity. Usually that's done by the car's engine, but you have to get the engine started first. [](https://i.stack.imgur.com/FZtlN.jpg) If you were REALLY smart you'd have brought a jump-starter with a built in battery and just jumped the car with that. [](https://i.stack.imgur.com/WyxWK.jpg) Put it right next to the [Chilton's Guide](https://www.chiltondiymanuals.com/), textbooks, spare gasoline and fluids, spark plugs, fuses, and all the other spare parts you also thought to bring with you before time traveling (or just have in your trunk because you're Ash Williams). [](https://i.stack.imgur.com/fAYCF.png) If you're smart, your time traveling car is a manual transmission. It's easier to repair and can be [push started](https://en.wikipedia.org/wiki/Push_start). A modest 5 to 10 mph is all that's required, rolling down a shallow hill or getting a few folks from the local inn to push. This provides enough mechanical energy to turn the alternator and generate electricity for the spark plugs to start the gasoline engine. Once the engine is turning, the alternator will charge the battery. (If you're smart you'd also use a diesel set up to run bio-diesel. If you run out of gas you can use vegetable oil. It also needs no spark plugs, one less thing to go wrong.) Push starting an automatic is much harder and [might be possible around 30-40 mph](https://mechanics.stackexchange.com/questions/19268/ddg#19286), but I wouldn't risk irreparable damage to the transmission. Instead, you'll have to turn the alternator manually. Most alternators need 500 to 1500 RPMs to charge and need less than 1 horse power. This can be done with leather belts (or adapt the ones already in the engine), simple gearing, and some way to get 1 horse power in medieval Europe... perhaps a draft animal, a wind mill, water wheel, some friendly peasants. I guess a horse will work, too. Getting the RPMs just right isn't very important, any car alternator in the last 50 years will have a voltage regulator. For payment there are any number of gadgets and tools in a car which would be worth a fortune in medieval Europe. A knife, lighter, calculator, clocks, flashlights, foam padding... even something as simple as a watertight plastic bag, or tiny springs and screws are amazing technology in medieval Europe. [Answer] # Hydropower The good news is that the Middle Ages in Europe were the first big expansion of non-animal generated power in history. Europe is pretty uniquely advantaged (along with Eastern North America...hmmm where did those Industrial Revolutions take place...) with having lots of perennial streams that have reasonably high speed and are constant year-round. This reliable energy source is going to give you what you need to juice up your time machine. The technology of water wheels were pretty well developed by the 'Middle Ages', and certainly more developed in the later parts. By the 13th century, dozens of smithies had relocated to the hills around Milan to use hydro-powered bellows to crank out steel for the Milanese armorers, merchants in Arezzo in Tuscany pioneered using hydro-power to mechanize throwing silk, etc. Check out further applications in [Cathedral, Forge, and Waterwheel](https://rads.stackoverflow.com/amzn/click/com/0060925817) by the Gies'. In any case, that is by far your best bet for a power source. A watermill can be expected to keep pretty constant flow on the timescale of day and will provide a steady rotational speed, which is of course the key to providing a reliable source of DC. Now you just have to build a dynamo to generate some electricity, and potentially some transformers or whatnot. This would be very challenging for someone who didn't have experience building one from scratch. But again, the upside is that the necessary skills are there. Bell-casters, particularly in the 14th century onwards when they started casting cannon, can make solid iron cores. Mail-makers have extensive experience with drawing the necessary wires. Now, your wires aren't going to be thin, and you will have to find some sort of insulating coating to put on the wires before you coil them into your generator's armature, but no one said this would be easy. The most challenging part is actually going to be the axle for your generator's rotor. There are no ball-bearings available, so you will have to use a greased wooden axle and hope for the best. You probably should monitor this apparatus constantly to be able to disconnect the power source from your machine in case of an (inevitable) accident. As for AC, this method would be easier for AC since you wouldn't need to make the brushes. This would make the copper-smith's job easier, and reduce the potential for mishaps (of the fire creating sort...high voltage plus grease and wooden parts...). Good luck! And definitely read up on DC generators (or bring a book) before you travel! [Answer] Only improvements to the other answers: What AlexP means are [voltaic piles](https://en.wikipedia.org/wiki/Voltaic_pile). The problem is that only a small current and low voltage is delivered by one element. So you need + to -, + to - (serial circuit) to increase the voltage n times and + to +, - to - (parallel circuit) to decrease the inner resistance, increasing the current with the same resistance. At least you will be busy for a time because if your time machine is battery powered, I expect that you need to rent a barn for the voltaic pile. This is the next problem: I hope your car has a comfortable and safe charger because evil things could happen if you increase the voltage/current too high or if you forget to stop charging. Lead acid batteries don't like such things, they are getting warm and can even begin literally to cook. The kingledion approach is also valid, but will also make you busy because you need to wind coils (and naturally a good, powerful watermill or windmill) to get kV AC. The only other way is a treadmill, so if you are able to get some people with endurance..... What does not work: * Lightning: Will only destroy your battery. Too much power in a too short timeframe, you have no way to get a consistent load and you cannot store the energy. * Solar: No photovoltaic cells available. You need silicon/germanium which is not available, it needs to be doped which needs technology you do not have, etc. etc. [Answer] For the kV AC you could build a Tesla coil, which is an RF step-up transformer. The AC would be generated from the DC supply by a spark gap in the primary side. You would need some hundreds of volts or more to keep the spark alive, depending on what material you had for the gap- preferably some graphite sharpened into points. That's just a matter of making enough cells in series (and they have to be fat enough to generate enough power that the arc heats the graphite sufficiently to allow a reasonably wide gap). RF will be much easier than trying to build a conventional alternator plus low frequency step-up transformer as you would not require a ferromagnetic core for either, fewer turns would be required, allowing cruder wire and insulation, and you would not have to find a water wheel or windmill for motive power. [](https://i.stack.imgur.com/stWaV.jpg) [Answer] If you can manage to get some metalworking tools and a permanent magnet, you can build a [homopolar generator](https://en.wikipedia.org/wiki/Homopolar_generator), which generates a DC potential difference between the disc's axis of rotation and its edge (link one electrode to the disc's axle, the other will be on a brush touching the edge of the disc). Then you can hand-crank it or link it to a waterwheel or windmill. Just make sure that you figure out which way to turn it to get positive voltage to the positive electrode! It'll depend on which orientation you put the magnet in... Regarding magnets, naturally-magnetic magnetite ore was known in Mediaeval times (under the name *lodestone* in England), and there was a modest demand for them as aphrodisiacs (!), so a large city might have some way of procuring them. Of course, if you can repurpose an existing magnet from your time machine (from the door of a mini-fridge, for example) it will be much easier on you. As a last-ditch alternative, it *might* be possible to link the generator's electrodes in parallel with a solenoid coil and make that into an electromagnet. I haven't calculated the circuit, but it might be possible that the Earth's magnetic field could provide enough magnetic field strength to bootstrap the electromagnet... [Answer] You could make a massive lemon battery using an entire orchard of lemons if need be. I'm sure you could calculate just how many lemons you would need. ]

[Question] [ I have a sapient (alien) species that behaves more or less similarly to humans, and that includes their romantic interactions. However, although they court/date each other much like we do, there is a certain mechanic that shapes their cultural understanding of romance. If a courting pair of these creatures lock gazes and share a warm fuzzy "love struck" moment, as we might describe it, their pheromone production spikes, and the ensuing surge of endorphins is so strong that it rewires their brains permanently, devoting the two individuals to each other for the rest of their lives. Pairs who have had this bonding moment have zero interest in infidelity and simply can't fathom getting a divorce, no matter how much they might argue. Non-bonded pairs exist too, but they are much rarer than bonded pairs and are generally either judged or pitied by the rest of society. The question is, what external stimuli could cause this soulmate mechanic to be favored by evolution? Right now it seems to me like it only serves to make individuals grieve all the harder when their mates die, because they can't "move on" the way humans can. Any suggestions? EDIT: Further details about the species: * The bonding process takes several seconds, and the individuals have some control over whether they want to allow it to complete. Often they're too swept up in the sensation to care, but it's possible to "snap out of it" if they recognize the sensation early enough and don't feel ready to commit. * The bonding moment typically happens after the couple has either been mutually crushing on each other or outright courting/dating each other for a while. There are rare cases of it happening at first sight, but these cases are usually one-sided and are considered to be foolish mistakes. * If one of these creatures loses their mate, either to early death or because they made the mistake of a one-sided bonding, they are *capable* of mating again with another person...they just typically don't want to, because the thought of betraying their mate would make them quite uncomfortable. Their biological urges to have sex and/or children may be strong enough to nudge them into taking a new mate anyway, but they'd most likely feel unsatisfied or even guilty. [Answer] **For raising children.** Let's say their world was rather hostile. Early in their evolution they could be attacked at any time. Having two parents to protect the young was therefore safer for the children. That is, parents who stay together will more successfully raise children. Once they've raised children that bond is no longer required, but there is no significant evolutionary pressure to *stop* being partners. They've already passed the pair bonding trait on to their children who will pass it on to their own children. It's especially likely to be as strong as described if the children are vulnerable for a long period. Only the very strongest pairs would stay together and would therefore be slightly more successful in raising children than those who did not. EDIT: There seems to be a lot of confusion here. This answer provides a *possible* reason that these creatures mate for life. There is *no guarantee* here. If you have an alternate mechanism or believe there is a way to guarantee pair bonding without possibility of cheating, then **post it as an answer**, there is no need to post extended comments here regarding your theories of pair bonding for animals on Earth. [Answer] To prevent sexually transmitted diseases. Among humans, sexually transmitted diseases can cause: * Infertility. (E.g., chlamydia) * Brain damage. (E.g., syphilis) * Birth defects. * Lots of other diseases. (E.g., H.I.V.) * Annoying itching and scratching. (E.g., lice, herpes, cold sores) Syphilis-induced brain damage is suspected as a factor in one of the World Wars. [Answer] I promised an answer, but I already made half my points in comments. I suppose I will make one more one. Most people have given justification for 'monogamy' but not life time obligatory monogamy like you want, so presume the answers above all apply to encourage serial monogamy, what will force a life time pair bonding? Paragraphs in parenthesis go into more detail explaining likely confusions about evolution in general, they better explain why an idea makes sense evolutionary if confused, but can be skipped for those familiar with evolution. Honestly, as I already implied it's pretty hard to justify. I do have an answer, but unfortunately I'm sticking to evolutionary principles, and the best way I can justify mandatory monogamy starts from a rather unfortunate start so umm...My answer is rape...lots of rape...*cough* Hear me out first there's a reason here... to be more accurate I'm referring to rape in the distant evolutionary past, particularly due to the resulting evolutionary arms race. Males try to rape females, females want mate choice so they develop means to prevent undesired pregnancy even if raped. This sort of arms race happens quite often, though less often in mammals. A side effect of this sort of arms race can lead to females being less fertile, they are so good at preventing unwanted pregnancy they start preventing wanted pregnancy as well because their defensive mechanisms are *too* strong. Again, this is not unheard of and has occurred in many species. ( why this happens. In an 'ideal' evolution a female would evolve a way to prevent pregnancy from rape without preventing pregnancy from desired matings. However, evolution is not guided, or quite so 'smart'. It is very hard to evolve such nuanced defenses. Instead it's likely that if rape is harmful enough to female they will ramp up defenses against rape, as an undesired, but better-then-the-alternative side effect successful matings from desired mates may also drop by a smaller amount. After this happens an independent evolutionary phase may work to help increase odds of successful matings with desired partners. Many species have these mechanisms, most obvious being numerous species that will abort pregnancy if exposed to a foreign male due to the odds of a foreign male killing their child after born. This can cause undesirable abortions at times when the foreign male was not a threat of killing the resulting child, but it *usually* saves resources to abort and so it was evolutionary favored even if it sometimes harmed mating success. After such defensive mechanisms exist later mechanisms can evolve to help better distinguish which mating's are desired if defenses are hindering successful matings too much. Which brings us to the next point...) So now the evolutionary problem to solve is how to allow the mates you *want* to mate with to have success when you have such strong defensive mechanisms. The answer is to have means to help accept a mate that your body recognizes. Pair bonding can be part of a process of creating not just a psychological but also physical connection to a mate which will actually help insure female anti-rape defensive mechanisms will recognize her mate's sperm and not attack it. (To be more accurate this isn't a simple chronological progression from A to B. Instead this would be a cyclic process, where increases in A or B encouraged further increases in the other. As The first anti-rape defenses likely only prevented a small number of matings, say 10% of undesired matings and 4% of desired matings. The original difficulty with desired matings put pressure on evolving the first limited mate-selection methods. As mate selection methods grew better it lowered the 'cost' of anti-rape defenses, as they didn't hinder desired matings as thoroughly, and so these rape defenses ramped up further, encouraging mate-selection to further evolve etc etc. As those defenses further increased the need to better identify desired matings increased and so on, each time one trait grew more refined it allowed, or encouraged, the other trait until eventually both were fully formed.) Mate selection mechanisms are not unheard of. Kissing in humans is not just cultural, it's evolutionary practice shared with many primates. There are now many evolutionary advantages to it (once something exists in a species they usually find multiple ways to exploit it), but the original cause of kissing was likely to help women be able to carry a mates child to term. In this case this was due to a very common STD that was dangerous if caught while pregnant or when conceiving, but not before. The best approach for primates to deal with it was was to *intentionally* catch it if you mate has it, via kissing and swapping saliva, when it was harmless, so that by the time your ready to mate you already have CMV and thus don't risk catching it when mating which could result in severe birth defects to the resulting child. The point being kissing, a romantic gesture now, started as nothing more then a physical act to help ensure a success when mating with a chosen mate. I would do the same with pair bonding, it is a way of helping the body recognize the mate so that mating success will exist later. I would change one thing, remove pheromones (which radiate out from someone so you couldn't have pheromones work on *one* person and not anyone else near by anyways) and make the bonding a more physical act, something that allows exchange of DNA so the female's body & immune system can start to recognize the mate. The obvious answer would be to use the above example, kissing. Kissing is the start of getting DNA from saliva to start recognizing your mate. It's not love at first site, it's love at first kiss. (note, it would have to be more then *just* kiss or a male can force a female to kiss him. However, if it requires a long continues length of time to build up the bond a rapist isn't going to hold a female captive for months to develop sufficient compatibility to mate) The more mates are close together, and exchange err 'body fluids' through kisses or otherwise, the more the female immune system recognizes the male and the better the odds of mating success. Thus life-time monogamy may be preferable because the odds of successful mating increases the longer the pair is together. From an evolutionary perspective a female may benefit from a system that causes a mate to spend extensive time with her before mating is guaranteed, not just to prevent rape but also to have more time to 'judge' the fitness of the male, to gain benefits from courtship (which likely involved male offering 'free' resources to the female to earn favor, and to encourage the mate to stick around to raise the child since they now have a better chance of successful mating with the female in the future. This is important because it would give evolutionary advantages for women to maintain traits that lead to pair-bonding even after the threat of rape was mostly mitigated. I would couple this with other mechanisms to prevent cheating, particularly to prevent females from consensual matings with males. as I mentioned cheating is quite common in all monogamous species and would discourage such strong pair bonding in most species. Have males have a method of reliably recognizing their children with a very high degree of accuracy. If a female births a child that is not biologically the males he will usually kill the child immediately in a rage. To make this work you would need to imply certain specific markings are carried exclusively on the male chromosome so that the male alone controls the marking and can recognize his marking with others (there is more to this, ask another question if you really want a full description for how a male can be confident he was not cuckold). This removes the advantage for the female of cheating on the male, and male would have little advantage of cheating since the female will rarely conceive from a mating with someone they haven't bonded with first. The strong ability to detect paternity could have evolved back when rape was common due to the increased odds of cuckolding due to rape for males, and would have further driven females to excessive biological mechanisms to defend against conception during rape due to the gaurentee that the child conceived will be killed at birth by her partner making conception from rape an entirely expensive waste with no evolutionary success. Eventually the rape-tendency will go away as it proves to not result in children, due to female defensive strategies, but the pair bonding will stick around for awhile longer. This would also *slightly* encourage what you wanted earlier, about a mate not trying to mate again after their mate passes. I stick with the statement that this would not normally happen. However, if the mates are older when one passes away the remaining mate may find it not worth trying to find a new mate because it would take too long to build the bond to the point where a mating was likely to be successful, and no opposite sex would spend that long trying to build up a relationship with an older mate that will die sooner leaving *them* in the situation of old maid unable to find a mate. Thus if your mate passes after a certain age the remaining mate may find it adventitious to instead focus on supporting his current children and family to help *them* achieve better reproductive success because no mate will choose to start bonding with them so it's not worth wasting energy trying to court a mate. Younger mates will likely still court new mates if their first bond dies young. Then again, if the bond builds over time they may not have the same emotional bond yet... Keep in mind the above only works if a mate that gives up on finding another mate is also driven to help it's family members find reproductive success, not just giving up and sitting around doing nothing with their life. That likely means providing grown children and siblings with food and resource etc so they can focus on raising their young. \*note, this implies a larger sexual dimorphism between males and females, with females being smaller, at least back in the more past, which is why females had to defend themselves via biological methods instead of claws and teeth. If you really want the two sexes to be close to our level of dimorphism there are some tricks you can use to justify dimorphism decreasing during the time it took for pair bonding to evolve, due to unrelated evolutionary pressures... Now, why this is still a lie... There are a few places where I'm bending evolutionary principles a bit to 'fit' the desired result, since as I said I don't honestly think this would evolve. I think this is a best-fit option and you likely can get away with handwaving the cheats, but I want to at least mention them so you are aware. Here is a quick list of my cheating: **Rape-mitigation strategies usually involve physical changes, not immune system** usually counter-rape evolution involve more complex vaginal tract that make the act of mating harder for rapists, or some way to stop the sperm of the rapist from entering the main reproductive tract. This is easier to evolve then some sort of immune system response to stop rape as in my suggestion. To counter this I would combine rape-migration strategy with disease migration. Some strong disease forced heavily ramped up immune responses in the species about the same time that rape-prevention mechanisms were evolving. The 'accidental' result of the ramped up immune system attacking sperm had the side effect of working as a rape-migration strategy which it got selected for. To make this work better I'd suggest an STD (or probably a collection of rapidly evolving/diverging STDs) being the cause of the ramped up immune system, to better explain why the ramped up immune system would attack sperm in particular. To make this work better you would need to explain why rape was still worthwhile to males if there was a non-trivial risk of STDs. Best explanation I can think of is a particular STD could be transferred from male to female via ejaculation but either did not migrate from infected female to male or, more likely, did not *harm* the male as much. For instance perhaps the virus only harmed a female's later reproductive success by making *future* implantation harder (but not ones resulting form the rape since the virus needs more time to spread before it has adverse effects). This would put the virus as a negative to the female but not the male, causing males to feel free to rape but females to develop strong STD immune system, that then also got specialized into an anti-rape defense. **Evolutionary pressures aren't enough to push such a strong extreme** This is my biggest cheat. All of this process could *start* as described, but probably not end like this. The problem is at some point women would become 'good enough' at preventing rapes that rape wasn't cost efficient, and at that point they would stop happening. This point would likely be before pair-bonding became 100% mandatory for successful matings. There are costs to this system as I defined it, and at some point rapes would be uncommon enough that they didn't warrant further opportunity costs, or simply didn't provide sufficient evolutionary pressure to get out of an evolutionary 'valley'. There are some things you can do to mitigate this risk, though I like one most of all. I suggest adding a competing evolutionary cousin living close to your species, one that is still very rape happy. The cousin species would attempt matings with females of your chosen species. These matings could lead to pregnancy, but rarely fertile children. This helps to ensure that females always need anti-rape defenses, because even after males of their own species have evolutionary pressure to stop raping the cousin species, who's females do not have sufficient anti-rape protections, may still maintain rape as a successful mating strategy and thus the males of the cousin species may continue to rape females of your target species. The males of the cousin species would not be as tempted to mate with females of your species, Kinophillia in general would make the females less attractive and they would not be gaining any major evolutionary advantage from it. However, they would not be suffering any significant cost for the attempted rape either, meaning there is limited evolutionary pressure towards the cousin species males evolving an instinct to avoid raping the females. Put another way raping of females (the ones of their species) works well enough for there to be strong incentive to evolve a 'attempt rape of any available female' instinct, and there may not be enough of a cost to failed rape attempts for males to evolve a more nuanced understanding of which females are worth mating and which are not. The males may also gain some secondary evolutionary advantage from attempted rapes of females from your target species. For instance perhaps it serves as practice for attempted rapes of females of their own species, with the learning experience being enough to incentivize attempted matings continuing. This isn't a perfect solution, since it's likely that females of your target species would evolve simply evolve a means to prevent pregnancy from ever occuring from matings with the cousin species (Since there is a difference in DNA between the two species any number of mutations may prevent hybrid children from being viable but not affect success of matings with males of the same species). Still, this could place an extra layer of pressure on the females at the same time attempted rapes from males of the same species, even if decreasing in frequency, was adding it's own pressure to help further push towards stronger immune response. For this idea to work the cousin species would have to have *once* been reproductively isolated, long enough for them to split off as a separate species, but that they now are less isolated. They likely were isolated for a relatively short time, thus the reason they still are similar enough to keep kinophillia low. This suggests either one species migrated away from the other, evolved into a new species, and then migration brought the two back into contact. Alternatively something 'temporarily' isolated the two species but limiting their ability to travel. For example after an ice age a river fed by glacier ice water grew too fast to be able to cross, separating the species, then after all the glaciers melted the river flow dropped down enough to make migration across the river easy again. A separate solution from the cousin-species one is to use my CMV example above. Make mate-selection partially about getting immune systems in sync to counter virus or disease. If you do this the original mate-selection process may not be just encouraged by rape by by immune system merging. I'd use both options honestly, you need all the excuses you can to encourage such a strong evolution. **There is no reason for both males and females to have anti-rape techniques** If males could successful identify cuckolding and kill the child then there would be no reason for rape as the child would not survive. It doesn't make sense for both female and males to have such well evolved anti-rape techniques since either one alone can make rape evolutionary disadvantageous. This is partially fixed by saying males are not always able to identify cuckoldry, or sometimes are less confident of when they identify it. while they sometimes kill children they are certain are not theirs, they also often abandon the female with the child, when they strongly suspect, but can not confirm, cuckoldry occured. The combination of possible infanticide with abandonment combine to put a heavy cost on females for having a child conceived from rape while giving enough of a chance for the child to survive to adulthood that rape may still be evolutionary advantageous to males. [Answer] # Make the connection get stronger over time At first, the connection is just a deep bonding with no other clear advantages, but with time, the creatures become gradually accustomed to each other's pheromones, subtle body language, ect. These things are unique for each member of the species and are able to quickly convey complex ideas. The bonding attunes the partners to learning to communicate with each other non-verbally, but the learning takes long enough that it's prohibitively expensive to start over with another partner. Their minds are only complex enough to extensively catalog one other person's idiosyncrasies, so polygamy is out of the question. Partners who have been together long enough might be indistinguishable from mind-readers. This amounts to huge productivity gains. Partners often have the same job and go to work together. Losing your teammate confers a feeling of nakedness/emptiness and makes you much less productive. Societies evolve to have disdain for people not in an effective partnership. External pressure for this evolutionary path might be that the species engages in a lot of activities where verbal communication isn't possible. If the species spends a lot of effort hunting highly-intelligent prey, having a mind-reader to flank with would be very valuable. Diving would be another example (are they amphibious?). [Answer] I'll add that if the children stay with the parents (pack animals,eg) the "selfish gene" theory comes into play. Since a sibling shares much of your genetic variability, it is genetically advantageous to support and nurture your siblings. Half-siblings do not share as many genes and the advantage of supporting them is reduced. [Answer] ## Shared responsibility for child rearing or greater female selection In the human species, women bear most of the cost of child-bearing. For a woman, creating a child is difficult, dangerous and expensive. It involves 9 months, millions of calories, pain, blood loss and significant risk of death. For a man, on the other hand, generating a child takes a few minutes of effort and a teaspoon of gamete cells. A man can potentially father many thousands of children in a lifetime. A woman is limited to 20 or so at the absolute maximum. Women are therefore much more likely to be choosy about a mate. The risk of taking on poor DNA or abandonment is much higher. ## Evolutionary pressures This disparity creates several evolutionary pressures: 1. The woman wishes to choose a mate who is stable and committed. Her children will be more likely to be looked after and will enjoy a survival advantage. She wants a good man. 2. The woman wishes to bear children by a man who is promiscuous. Her children will be more likely to sire many children by multiple partners, spreading her DNA. She wants a bad boy. 3. The man wishes to appear stable and successful to attract a mate who will be committed to him. The successful male. 4. The man wishes to appear wild and promiscuous to attract multiple partners to spread his DNA widely. The rock star. 5. The man wishes to bed other women who are already in a relationship, so another man will expend effort raising his children. The woman looks for the bad boy. Marital infidelity. ## Broad vs. Narrow So there are several valid strategies. Do we spread our DNA widely, do we focus on a few children, or does a male attempt to pass off his progeny as another male's progeny? Is it better to spread seed widely, or to focus on a few offspring? What are the costs and benefits of each strategy? The woman will evolve to choose the partner or partners who will be most effective at spreading her DNA, as will the man. The difference between sexes is caused by the disparity in the cost of child rearing. On earth currently both strategies are in balance so both are extant in modern humans. ## The solutions 1. Increase the cost of infidelity. Make infidelity more obvious. Perhaps pheromones, or a distinctive inherited callsign. Perhaps infidelity is punished severely. Do this for a few hundred generations and the gene will disappear. 2. Increase the cost to the male of child rearing. This might be a calorific cost or a cultural cost. The male can no longer produce lots of free children, so will choose more carefully and commit. The pressure on the woman to choose a bad boy will be reduced as the bad boy strategy is less successful. 3. Decrease the survival chances of unguarded children. The male selective pressure to procreate widely is reduced if almost all children, not guarded by a male, do not survive. The female selective pressure to choose bad boy genes is also reduced. The dangerous environment need not be current, it only needs to be in the recent evolutionary past. [Answer] As I understand you want a society that's very much like humans except for being truly monogamous - so here's an idea on how to not solve, but circumvent the issue: ## Behavior-altering parasite Not a total takeover by hostile intelligence, like the one SF novels. Something very real and well known, [Toxoplasma Gondii](https://en.wikipedia.org/wiki/Toxoplasma_gondii), that subtly nudges it's host in the direction it wants. *For those who're not yet familiar with our unseen overlords, Toxoplasma infect rats and then wants to move on to a cat. How to do it? Just turn a rat into careless risk-taker - and a cat will come along. Of course, it can't tell apart human from a rat, so infected humans get more courageous and underestimate risk just as well.* Now this is just taking an issue from one place (your aliens) and putting it into another one (their parasites), however it has some advantages: * No longer your protagonists chose to give up breeding after losing mate. This choice is forced on them by another species, so it's more likely it can be made plausible and beneficial - for the parasite, of course. * The parasite might have evolved to control another species. Maybe one that lives shorter and in harsher, more monogamy-requiring environment. Then it dead-ends in your aliens just as Toxoplasma does in us and the lifelong monogamy is unintended side-effect. * Your readers are more likely to spot inconsistencies in design of human-like species (hey, if they are so much like us, why they do X so differently?) than to question your design of some "evil" protozoan. * If you chose to explain toxoplasmosis (eg. by a human scientist explaining the parasite to other humans) at least some of your readers will be so shocked by discovery THEY (eg 84% of France) are being mind-controlled, they'll stop caring about plot holes : ) [Answer] It could be a survival trait, if there was an evolutionary reason to need a partner you can implicitly trust. For example, let's say there is a species of tree on the alien planet. The tree has a fruit that is both highly nutritious and highly delicious to your aliens. The fruit grows fairly high up, and by the time it falls is mostly rotten. And the trees do not have terribly large yield. Enough to feed two or three people. But the tree also has a tentacle, with a poison barb on the end. The tentacle is quick, but only goes after anyone climbing the tree. That said, it is also not very strong, and can be restrained. So getting the fruit is most effective in a two person team. The female aliens are lighter and more dexterous, making them better climbers to get the fruit. And the males, being stronger and heavier, have an easier time restraining the tentacle while someone gets to fruit. So said two man teams tend to be male/female. Of course, the problem is that it is fairly easy to betray your partner. Then male lets go of the tentacle after the female has some fruit, letting her get stabbed and taking the fruit for himself. Or the female could throw the fruit to a third person, or just run from the slower male (who is still holding the tentacle) when she gets to the ground. That said, not betraying your partner, and trusting them not to betray you, leads to a higher survival rate as both are happy and well fed. Over time, this bond of trust begins to become part of their DNA. Looking at someone, knowing them and thus knowing that you can trust them, it is a huge advantage in the harvesting. Such pairs tend naturally to mate, and thus over time the harvesting bond becomes a mating bond. [Answer] Monogamy of any kind as a mating strategy in Earth biology is the simplest and easiest form of teamwork in a competitive society with two-gender sexual reproduction. The basic idea is that both the male and the female parent have the most vested interest in getting their offspring to maturity, and two providers are better than one, especially in harsher climates. On Earth, prolonged monogamy is actually fairly uncommon; virtually all species traditionally thought to exclusively mate for life, on closer inspection, "cheat" on a semi-regular basis and so are closer to serial monogamists. The majority of social mammals have developed a patriarchal harem structure; one or two sexually mature males, a larger number of females and their immature children. Those that pair-bond for a mating season tend to be serial monogamists. There are two main reasons this is so: * Females have all the biological equipment necessary to carry, bear and care for the baby in its early life. That means the male's primary job is done in about ten to thirty seconds; if he sticks around after that it's as a guardian. * The best overall strategy for diversification in the genetic pool (the primary advantage to sexual reproduction versus everyone just popping out exact clones of themselves) is to have as many matings between different males and females as possible. That produces a large number of genetic combinations that are tested for fitness by nature to produce beneficially-evolved specimens. That generally leads to four dominant strategies for males of Earth species: 1. mate and die/be eaten (most insects/arachnids), 2. mate with any willing female and then move on to the next as many times as you can until you die (most reptiles, solitary mammals and birds), 3. build/take over a harem of females and mate with as many of them as possible for as long as possible, until another male dethrones you and you either die in the fight or live out your old age alone (most social mammals), and 4. pair-bond with a female to guard and provide for your mate and the kids until they're big enough to fend for themselves, and then move on (a few mammalian and bird species). Anthropologically, the rise of human civilization has given our species a fairly even mix of genders as of the age of sexual maturity. We look down on incest because it produces misshapen children, so we don't keep our daughters around to mate with, while kicking our sons out to fight another man to the death for their women. That makes monogamy the path of least resistance, with a few societies tolerating polygamy among the very successful. The average length of human monogamy is notable primarily because the gestation and maturation periods of our species is so damn *long*. Most other mammals are able to fend for themselves in one to two years and sexually mature a couple more after that. Human children don't even start their sexual maturation until *12 to 14 years* after birth, though they can become productive members of the society somewhat earlier, and really puberty doesn't wind down until the mid-20s. By the time a human child is really ready to strike out on their own, the parents are usually long past their sexual prime anyway. So, the human strategy is to stick together, have a bunch of kids, and raise them together as a couple, after which time you might as well continue to stay together for mutual support. So, that would be the first evolutionary advantage to exclusive pair-bonding in some non-human species; if the species takes the majority of the adult lives of the parents to mature, that child has the best possible chance if the parents stay together the whole time to provide for and defend it. Any evolutionary trait that makes that more likely, such as forming a neurobiological bond, is a trait that will advantage the species as a whole. Additional traits not seen on Earth that would require both parents might include some basic biological need for increased male participation in childbearing/childrearing. Picture a species that is otherwise humanoid, but the male has the mammary glands and/or some other necessary biological feature, like a marsupial pouch. The female carries and bears the child, but the father's required to be around to feed or care for it or else it will die. That makes the fourth male strategy the only truly viable one; all the others depend on the female to be able to handle everything else after mating. A biosphere with animal species that required significant participation by both genders would benefit greatly by hard-wiring an attraction to exactly one of the opposite sex. [Answer] It benefits the alphas at the top of the collective structure, not anyone down below. Actual behavior in historically "monogamous" societies tend to reflect this. Consider that at the height of the Catholicization of Europe ordinary people had monogamy imposed on them based on a rather creative interpretation of [1 Corinthians, chapter 7](http://www.biblestudytools.com/1-corinthians/7.html), the ultimate outcome of which was that there were three tiers of society, and only two were permitted political power: 1. The clergy were to remain unmarried "as Paul was" which *implies* celibacy (otoh, with great power comes great privilege). The church wielded profound political authority, but this was tempered by the fact that establishment of dynasties was problematic, as unmarried clergy were unable to have legitimate offspring under typical circumstances (consider, though, the interesting tales, political and genetic, of [Popes who have been named Alexander](https://en.wikipedia.org/wiki/Pope_Alexander)) 2. The ordinary peasantry, ungraced by God and limited in privilege in almost every way, but absolutely necessary to the maintenance of every nation, were permitted monogamy. 3. The royalty, extremely wealthy, various forms of aristocracy and other elites were ostensibly to live under the same rules of monogamy as everyone else -- unless they didn't. And very few did. Fascinating processes for absolving marriages, overlooking multiple marriage, flexible rules regarding incestual unions (by varying definitions of "incest" depending on the case), legitimizing bastards, and simply overlooking extramarital unions (or even celebrating them publicly) is the norm throughout history. This is just Europe, but we find parallels all over the place, in every period. Consider that today a large patch of the "conservative Right" ([an hilariously misleading label](http://zxq9.com/archives/393), but whatever) supports Donald Trump, of all people, but he certainly is a man who has found it perfectly reasonable to selectively breed with many of the top lines within his scope of preference. And evidently people think that's just great. The most staunchly monogamy-interested section of the political landscape is this guy's voting base (for some *this* particular issue is a hangup, but the majority seem to just overlook this entirely). So its not about "evolutionary benefit" in human genetics as much as "social control" in human society. At the level of structural evolution of societies there may be some significant benefit, but that is a tier of evolution entirely above chemistry, and one we refuse to allow ourselves to understand well yet. I don't think we've ever seriously studied that without projecting our own politics into it (and corrupting the results). I imagine in terms of letting genetics experiments occur and die -- pure organic progression of the species -- monogamy is probably a bad thing, *especially* in the case of low-birth rates (each new person then becomes a one-shot recombination experiment). In absolute terms, prohibition against incest is a similar problem -- but its not like we're going to treat people like animals and inbreed them, culling the bad ones until we *actually* [purify a desired set of traits](https://en.wikipedia.org/wiki/Belgian_Blue). [Answer] **Make the cost of breeding equally high for both parties.** As several people have pointed out, being choosy about your mates is advantageous for females, while being blindly promiscuous is advantageous for males, the upshot of which is that it is evolutionarily most advantageous to appear to be monogamous but cheat when you can get away with it. I don't feel the need to repeat the full explanation; others have covered that quite well. However, you are talking about an ALIEN species. If males (for lack of a better term) can ALSO only successfully mate a certain number of times in their life, like earth mammal females, then they are going to evolve to be equally picky about their mates. Maybe the females carry the infant to term but then the male nurses it. Maybe the males don't have re-usable penises, but have something like a bumblebee's stinger which is used to deliver sperm, and after mating they need to heal and then re-grow the organ over a period of months. If the males have a high enough investment in conception, the successful strategy will be to stick around and ensure the survival of the offspring, rather than just sow widely and hope for the best. **Allow both partners to quickly know when conception occurs** There is one type of cheating that the above doesn't address, which is cuckolding. If a male can impregnate a female who will then get some OTHER male to help raise your offspring, that's still an evolutionary win, so, as others have mentioned, having males be able to recognize their own offspring beyond reasonable doubt is a good way to prevent cheating by partnered females. However, as was also pointed out, that's really hard to justify. However, I think it would be a lot easier to justify being able to recognize that conception had occurred. Then you just apply logic: if your partner is pregnant, and conception did not occur while (or shortly after) you were shagging her, then the kid is not yours. **Combine with other answers and shake well** The above only really gets you as far as serial monogamy, rather than life-long monogamy. However, if you use some of the other ideas for why they would keep the same partner for life, raising the cost of conception for the male enough, and reducing the chance of cuckolding going unnoticed, should strongly reduce or eliminate the advantage of cheating. [Answer] The advantage lies in the fact that a single partner will result in many reliably strong children throughout their lives. You don't have to worry about possible unexpected consequences of a new partner, because you already know that one partner well. ]

[Question] [ A lot of fantasy stories involve someone using magic or technology to solve a problem, only to find out the spell or thing they used to solve their problem was a little too potent. Let's say a wizard invents an alchemical like spell that creates gold. It's not created from nothing though, it's just transported from somewhere else. The spell turns out to be a little too potent, and the unfortunate person ends up receiving more than he bargained for: **all the gold in the solar system**. Note: Assuming the solar system in the story is similar to ours: This is about $2.0 \cdot 10^{21}$ kg of gold1, or about 2.7% of the mass of our moon. If the spell summoned the gold as one big cube, it would be about 470 km on each side, comparable to the size of a small country. Assume the cube is initially at rest compared to the wizard's position. What happens to the world? I'm guessing everyone dies, but just how quickly does that happen? 1: I obtained this figure by using the approximate mass of the sun ($2.0 \cdot 10^{30}$kg) with this resource detailing relative abundances: <http://www.periodictable.com/Properties/A/SolarAbundance.html>. The contribution from other objects is negligible given the uncertainty we're using. **Details**: I haven't explained in detail enough 'what kind' of thing happens with the stuff that's in the place where something's teleported to. The details can be important with this scale. (e.g. Doctor Who style, or Steins gate style?). You can assume the Doctor Who variant: so you 'swap' the location of the stuff being moved (there's no temporary absolute vacuum). Let's also say that the physics of it prefers a low-energy, high-entropy solution, but we arbitrarily award entropy for putting a particle closer to where the wizard pointed to. So right at the epicenter the stuff is probably embedded into the earth a bit, but mostly towers up into the sky. It's also ordered randomly. It's also true that the average temperature of the material is something on the order of $5 \cdot 10^6 K$ (as our gold mostly comes out of the center of the sun...). However, if you calculate the amount of thermal energy that equates to about 650 kJ per gram, it's far less than what you'd require for the $\Delta v$ (at least $570\hspace{1mm}\mathrm{kms^{-1}}$, which would take far more energy per gram2), or the kinetic energy because of all the random speeds the particles have. You can assume the magic solves these effects: it uses the thermal and kinetic energy (down to room temperature and being at rest wrt. the wizard) to power a small part of the spell (the other energy comes from unobtanium). 2: Figure obtained by subtracting solar escape velocity at earth's position from that on the sun's surface. [Answer] ## tl;dr I'll study the macroscopic consequences on Earth, since the question could be addressed from a lot of different points of view. **Assumptions:** * Both momentum and angular momentum of Earth are conserved. * The gold starts at rest with respect to the Earth (sorry, no [Chicxulub-impactor speed](https://en.wikipedia.org/wiki/Chicxulub_impactor)) **Main outcome:** 1. It will probably break/heavily sink Earth's crust, causing—at least—huge massive earthquakes, very likely lava flows and, if the place is close to the sea, floodings. 2. It will also slightly change the Earth's orbit and spin. And depending on the location of the gold, its tilt, which would drive world-wide climate change. **Updates:** 1. I've added some considerations about the latitude at which the gold appears (*thanks to Otto Abnormalverbraucher*). 2. Added two figures for perspective --- ## Details Your calculations seem right, assuming the $1\times10^{-7}\%$ solar abundance is by mass (which seems to be the convention). 1. Earth crust's thickness varies [from 6 to maybe 70 km](https://en.wikipedia.org/wiki/Earth#Internal_structure). So a cube of 470 km a side will undoubtedly start sinking it and will most likely break it. Gold ($19.3\,\mathrm{g/cm^3}$) is [much denser](https://en.wikipedia.org/wiki/Earth#Internal_structure) than the crust ($2.5\,\mathrm{g/cm^3}$), the mantle ($4.5\,\mathrm{g/cm^3}$) and even the core ($\sim12\,\mathrm{g/cm^3}$). Ice alone can sink land masses, and its melting may [make land masses rise again](https://www.popsci.com/as-its-ice-sheet-melts-greenland-is-rising-faster-than-expected). The effect, with a lot more mass and all of a sudden (ice is less dense than gold, may be a couple kms thick and has taken decades to melt) will have a much more dramatic effect. To put things in perpective, consider the comparison of size between the Earth, its crust, and the cube: [](https://i.stack.imgur.com/HSLgT.png) * The blue dot is Earth's center. * 1 px in the original image is 10 km, the crust is on average like 2 pixels thick. **It *would* break, wouldn't it?** Luckily I drew this with paint, so you can see the pixels (no antialias; click to see the original size). * If you see a quarter of an ellipse, it's most probably your screen's fault: Earth's polar radius is about 2 pixels less than its equatorial radius. Now let's compare the cube to some popular layers of Earth:[](https://i.stack.imgur.com/X9LWH.png) * The cube is golden (hahaha, funny, right?) * The sea is dark blue, gray is litosphere/crust. I tried to fit the crust's maximum and minimum thickness in the figure * The Earth's mantle is in orange * You can see the heights of Mt. Everest and Mariana Trench (width not to scale, I have no idea about that, to tell the truth) * The two light blue layers are the Troposphere (where life and airplanes happen) and the Stratosphere (it has the ozone layer in the bottom; at the top, pressure is 1/1000th of standard air pressure) * The dashed line is where outer space is considered to begin (although you can find a few air molecules even above the cube) * The purple band is low earth orbit (LEO). If your world has artificial satellites and the cube is in the equator, some will crash. If the cube didn't sink nor loose shape, all satellites on LEO, including space stations would eventually crash.Side comment: this would be an effective method to [*sink* the Netherlands entirely and permanently](https://worldbuilding.stackexchange.com/questions/115597/how-fast-can-i-flood-the-netherlands-entirely-and-permanently)... or Germany: [](https://i.stack.imgur.com/BCHmf.png) 2. You are adding $\frac{2\times10^{21}}{6\times10^{24}}\approx0.03\%$ to Earth's mass. This affects Earth's spin and the force with which the Sun attracts Earth. * The gold will change Earth's moment of inertia. Assuming angular momentum is conserved AND the gold appears at the equator, this will slightly change the angular velocity of Earth's rotation: $L=I\_0\omega\_0=I\_1\omega\_1\rightarrow \omega\_1=\omega\_0\frac{I\_0}{I\_1}$, now, putting the gold as a point mass, and the Earth as a solid sphere for simplicity: $I\_0=\frac{2}{5}m\_\mathrm Er\_\mathrm E^2$ $I\_\mathrm{Au}=m\_\mathrm{Au}r\_\mathrm E^2$(\*) But $I\_1=I\_0+I\_\mathrm{Au}$, so $\frac{I\_0}{I\_1}=\frac{I\_0}{I\_0+I\_\mathrm{Au}}=1-\frac{I\_\mathrm{Au}}{I\_0+I\_\mathrm{Au}}$, and we can simplify by $r\_\mathrm E^2$ $\frac{I\_0}{I\_1}=1-\frac{m\_{Au}}{0.4m\_E+m\_{Au}}\approx1-\frac{10^{21}}{0.4\times6\times10^{24}+10^{21}}\approx0.9996$ With a slower angular momentum, **Earth's rotation will take** longer, namely $\frac{86400}{0.9996}-86400=36\,\mathrm s$ **longer. Which is slight, but enough to mess time measurement quite a bit**. (\*) If the gold mass does not appear at the equator, we would have $I\_\mathrm{Au}=m\_\mathrm{Au}r\_\mathrm E^2\cos^2(lat)$, the higher the latitude, the smaller the change. * Now, rotation is supposed to drive mass to the equator (hence the faster the rotation, the higher the body's flattening, compare Jupiter's 6.5% to the Moon's 0.1%). If the mass suddenly appears far from the equator would mean a mixture of a change in the earth's overall shape (the [geoid](https://en.wikipedia.org/wiki/Geoid) and land masses) and in the rotational axis, which would affect the axial tilt. Even a slight change in axial tilt would in turn affect seasons and climate: Consider that a change in less than a degree in axial tilt, [made the Sahara a desert](https://www.astrobio.net/news-exclusive/how-earths-orbital-shift-shaped-the-sahara/). * Assuming momentum is also conserved, the speed of Earth relative to the sun should also change. Mass is said not to affect a body's orbit, *provided speed remains constant*. A slower speed would mean a closer approach to the sun after half an orbit (expect more sun radiation the next season). $p\_E=m\_0v\_0=m\_1v\_1\rightarrow v\_1=v\_0\frac{m\_0}{m\_1}\approx v\_0\frac{1}{1.0003}\approx 0.9997v\_0$, but how closer will the closer approach get? This can be estimated using [Hohman transfer orbit](https://en.wikipedia.org/wiki/Hohmann_transfer_orbit#Calculation)'s equation: $\Delta v\_1 = \sqrt{\frac{GM\_\mathrm S}{r\_1}} \left( \sqrt{\frac{2 r\_2}{r\_1+r\_2}} - 1 \right)$, where $G$ is the gravitational constant, $M\_\mathrm S$ is the mass of the sun, $r\_1$ is the Earth's orbital raduis (assuming a circular orbit prior to the appearance of the gold, for simplicity) and $r\_2$ is the new close approach. Now we want to know $\Delta r=r\_2-r\_1$ from a known change in speed. Taking into account that $\Delta v$ is proportionally small, we can solve for $\Delta r$ and linearize: $\Delta r=\frac{4\times\Delta v\times r^{3/2}}{\sqrt{GM\_S}}\approx1.7\times10^8\,\mathrm m$, about a couple hundred thousand kilometers, or **a 0.1% closer**. This is less than the actual difference between the current perihelion and aphelion, so probably the axial tilt of Earth will continue to drive seasons. Temperature could increase by a (small) fraction of a degree, unlikely to be noticeable in yearly weather's variation. [Answer] What happens to the world depends largely on the nature of the magic used. If for example, the magic respects conservation of energy, then the gold is going to arrive in a variety of states and temperatures. The portion stolen from the sun's core will be a little warm, maybe even gaseous. With a such variety of temperatures all forced into one cube the result would probably be an explosion. If the magic also respects conservation of momentum then your gold cube is only going to stay cube shaped for a millisecond. In its pre-summonsed state, each part of that golden horde was rotating around (or within) the sun on a separate vector and at a separate velocity. If all that motion is maintained across the summonsing, the result will probably look a lot like an explosion. Now let's imagine the extremely rare case where the world builder is actually nice to their characters and allows the magic to solve all the problems inherent in galactic scale grand theft... the poor souls still have to deal with physics. Gold is heavy. Something tells me that if you stack a bunch of gold coins in a 470km tower under earth level gravity, the coin on the bottom is going to be under a lot of pressure. Maybe even nuclear fission level pressure. So once again, an explosion. TLDR: an explosion. [Answer] **Too Many Catastrophes** Ok so by magical a cube of 470km appears out of nothing. For mercy I will consider it appears cold and at rest (no need of a gold huge meteor), in a flat desert land and avoid nasty things like all the air moved the volum of the cube moved (the shockwaves per si can make any nuke looks like a small bang). Also let's say the cube keeps a cube by magic, otherwise you can think all that mass as a sort of high viscouseus liquid spreading very fast as a golden tsunami for over even a bigger area, maybe covering a continent and hitting the sea with nasty environmental consequences. Note also some of the sea salt is made of gold but I'm unsure how it can affect sea wildlife. For sure the sea can become a slight less dense. Not the last catastrophe can be the mass of the cube ripping trough the planet crust and reaching the mantle this is very speculative but one can expcet volcanos erupting and earthquakes all around and not even start to think about all that gold sinking to the core. Let's also make the magic protect the planet rotation, you know what can happen if you concentrate mass in a ball? Well put a small lead pin in a baseball ball side and throw it, thats what they call an odd ball. If there are sattelites over this planet their orbits can be affect by a huge [Mascon](https://en.wikipedia.org/wiki/Mass_concentration_(astronomy)) (sorry ISS). **Economics** Rulling out all the world destruction thing we still will see bad things happening because gold is valuable because it's rare. Unless some major global power throw all his military at protecting the cube, maybe triggering a world war, gold now is a very ordinary thing. You can have balast make of gold to use in fishery, use it to make water pipes and so on as it now can be as cheap as lead (just a bit less unhealthy). How gold will trigger an economic crisis depends on your world setup. In a medieval setup kingdoms will slowly change all his currency to silver. Powerfull kings will be less powerfull. In a a more renaissense world the new formed banks sinks, the merchants are almost bankrupt and say goodbay to arts patronage. In a modern earth like society we are screwed, badly. Gold is an important commodite. The bottom line is: The poor fool wished all the gold of the world is now more poor ans screwed than before. [Answer] Here is a slight variation that tries to take into account the working of the spell in a way that deals with the air displacement, the requirements are: 1. The spell consumes momentum of whatever it teleports (see OP's edit, I accidentally wasted a lot of my time describing what the cube's motion might look like if the spell optimizes the teleportation process). 2. The spell actually produces a cube of gold for at least an infinitesimal amount of time, in a non-gaseous form 3. The spell is designed to avoid instantly killing the witch/wizard that casts it. Let's say the witch/wizard was wise enough to take these two precautions: 1. the radius of effect of the spell excludes a protective shell around the witch/wizard's body just in case gold is involved in any biological process. (side note: is it? I don't suspect it, but one is never too sure). 2. when it breaks a chemical bond, it teleports as many electrons as needed to keep the gold atom neutral, i.e. 79. The total polarization of every single gold atoms in the solar system might not be perfectly zero. Given the amount of gold, a slight variations might result in a major thunderstorm, but that also gets too impredictible to my taste. I will assume the spell works like this: 1. Locate all gold atoms in the radius of effect of the spell. Exclude any gold atom that might be present in the witch/wizard's body. 2. Sort the atoms by distance from the witch/wizard 3. Teleport the first atom where the wizard demanded 4. Teleport the next atom to a position randomly chosen in the vicinity of the cube's forming surface, excluding the face touching the ground. Any atom's momentum is consumed in the process, but the relative electron/nucleus momentum is maintained. 5. Wait for a small time interval $dt$, then repeat steps 2,4,5 until atom list is exhausted or spell caster is dead. This will result in the gold atoms in the ground just beneath the spell caster to be teleported first, forming a small ball of gold that first crystallizes to a cubic arrangement, as this is the preferred lattice structure of gold. All atoms would then gently attach to the surface and conform to the cubic lattice already in place. Therefore each face of the cube would expand by 1 atom per 5 $dt$ on average, leading to a cube of side: $$L(t) = a\times \left(\frac{t}{5~dt}\right)^{1/3}$$ where $a$ is of the order of $10^{-10}$ m. The important point is that because of this power 1/3, the perceived velocity of the face by the witch/wizard gets smaller and smaller. Let us just assume that $dt$ is chosen (perhaps automatically adjusted over time, letting $dt = f(t)$) such that this expansion pushes the air and everything else around "gently", effectively a quasi-static push, raising the radius of the atmosphere a bit. Now in the vicinity of the spell caster, there might be plenty of gold available, producing a giant cube of gold similar to what the witch/wizard was expecting. Since gold is generally found in alloys, these would shrink progressively, but it gets more interesting as gradually the spell starts tapping into Gold(III) chloride in the oceans. Leaving unbound Cl atoms everywhere. Now, gold is particularly un-reactive, which is part of why it is so valuable and therefore why the spell was cast in the first place. In contrast, Cl is VERY reactive. Although the Cl atoms are neutral immediately after bound breaking, they will react with any organic substance they will find in the ocean. A significant part of it might simply form Cl2 gas, that should quickly start its rise to the surface. According to Wikipedia, ClAu3 is present in the ocean in concentration of the order of $10^{−8}$ g/cm$^3$. However that can't possibly be the average concentration as it is waaaay too high if you multiply it with the gigantic volume of the oceans (that would be of the order of gigatons of gold if my calculations are correct). Nevertheless, my guess would be that this represents a huge amount of gas. Here is a translated quote from the French wikipedia entry for Cl2: > > [Cl2] has a very unpleasant suffocating smell and is extremely toxic because it combines with mucous and lungs' humidity to form acids that attack tissues > > > Cl2 is much denser than air but much lighter than water. Therefore it will erect from the ocean and creep at Earth surface, intoxicating everyone that leaves close enough from sea level. It's difficult to say wether this would kill all humans because I don't have access to the total amount of Cl released in this way. If it is small enough it might form a thin layer at sea level? But how thin exactly I could not tell. Cl2 should be consumed fast though, since it can react with pretty much anything present on Earth's surface. So again it all boils down to how much amount comes out... It's also quite likely that a large fraction of Cl will react with organic compounds in the ocean way before it reaches the surface, leading to pollutions of some other form. In any case, polluting the whole fricking ocean in just one day would certainly have nasty effects on sea life and climate, with inevitable consequences for us. All the while, gold escapes all electronic devices of the Earth (we neglect dentistry devices). Now this is not as violent as you might expect, because it goes out atom by atom, reducing very gently its conductivity to zero, bringing the devices to open-circuit conditions. Therefore I do not expect much electrical hazard. The main problems would come from the engine in which they are embedded. As all computers in the world gradually shut down, the commands of engines, planes, trains, boats, stop responding. Planes would certainly crash, as their controls, sensors and communication to the outside all shut down. I don't know how much electronics are involved in trains but they do have an emergency brake that is purely mechanical (at least in France), so driver might be able to save lives. Automatic track orientation might fail too. Satellites in the area start failing too. Solar cells all stop producing any of the current that no device is consuming anymore anyway. More importantly, a number of hospital devices cease to function. In general, numerous hazards could be expected from the lack of control over virtually any machine that has an electronic interface. Those in motion come to rest in whatever way. Perhaps gently in a number of cases. At this stage, the news have been broadcasting on every channel about strange reports of failing engines, car crashes, and fail to report unusual Cl2 levels over the ocean, as this would seem irrelevant in comparison to the much more visual effects of electronics. One by one though, all radios and TVs stop to deliver those news. Fewer and fewer people manage to reach their loved ones by phone or facebook. At this point, a number of people would perhaps panic slightly. Those who take their cars to flee find themselves stuck in massive traffic jams that are not regulated by any traffic light. It gets worse as more and more of these cars stop functionning properly in the middle of the road. Added to the overall nervosity, I guess the risks of car crashes is huge. People in the countryside would probably be slightly less affected but are out of power too, meaning all the refrigerated food is doomed. Those who will survive till the end of this spell could experience some difficulty to feed themselves. Assuming the cube has reached the point where it has accumulated all the gold from Earth, it starts tapping in the sun, and the witch/wizard starts to back down as it gets clearer and clearer that the cube's advancing front is going to crush anything on its way. Again, there is freedom in $dt$ so running might be unecessary, but the cube is going to be 470 km long ultimately. Out of any transportation mean (the locals have used any animal they could possibly find to carry them as far as possible), the witch/wizard eventually gets exhausted and falls. The cube rolls over them, breaking loop (5). [Answer] Even ignoring all the other catastrophic effects (magic fixes them all, say), you now have a really, really huge "mountain range". Depending on how much it sinks/spreads out, it still has a really good chance of sticking right out into space (ozone layer: ~50km, "edge of space": ~100km). Compare to, say, the Rocky Mountains--this wouldn't be as long, but the extra height means that really no weather can get across it. So say you plonk it right in the middle of an air current coming off of the coast. The wet side is going to get a lot wetter, and probably experience a ton of erosion around the edges. The dry side is going to turn into a desert, if we look at the Dust Bowl period that could happen in maybe a decade (or less) and probably also experience erosion as the plants die off (root die off will stop holding the soil). Winds along all sides that run parallel to the sides will probably get a lot stronger. On top of that, gold seems to be slightly lighter in color (and more reflective, even in a raw state) than most natural surfaces, so that might cause the surrounding area to get a bit cooler (sort of like a reverse heat island). Having a large area sticking out of the atmosphere and reflecting heat/energy before it even gets trapped by the greenhouse effect would probably also cause a strong cooling effect. (I'm trying to base a lot of this on water currents around large islands and air currents around normal mountain ranges.) [Answer] The other answers result in a wonderful "everyone dies" scenario, so I'd rather look at a different interpretation of "all the gold". This is related to the question, but changes one of the assumptions. In this spell, "gold" applies only to the element where it has aggregated into particles which exhibit the large-scale properties of metallic gold. Individual atoms, gold nanoparticles, and gold suspensions are not transported. Only aggregates large enough to be recognized as gold, such as gold dust in a pan, or nuggets found in rock. And, since gold aggregates are produced by biological processes found only on earth, the spell only summonses gold from the earth. In particular, the gold content of the sun is not included, nor is any undifferentiated gold found in non-biologically active planets summoned. The resulting gold mound is much smaller. Magic bypasses any negative effects of temperature, momentum, or energy balance. The [abundance of gold in the earth's crust](https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust) is, by two estimates, 0.0011 or 0.0031 ppm. Assume the average of elemental gold 0.0021 ppm, or 2.1 parts-per-billion. I estimate that 1% is in aggregated particles, giving an amount of Magically accessible gold of 0.021 ppb. The [mass of Earth](https://en.wikipedia.org/wiki/Earth_mass) is 6x10^24 kg. The total amount of gold summoned would be 1.26x10^14 kg. At 19,300 kg/m^3, the spell yields 6.53x10^9 m^3. This is a 1.86 km cube. Surely this is a lot, but it stays well within the atmosphere, doesn't disrupt global weather, and, although it may cause some local crust compression, doesn't kick off global volcanism. What it does is make gold worthless, and where it was used for it's chemical properties, things break down. No one has gold to exchange for currency or barter. No gold jewelry. No gold leaf protecting roofs. Electronic connectors corrode more quickly. Some uses of gold may still possible, such as magenta inks and dyes, because they aren't made of aggregated particles, but manufacturing them has to start over since all the metallic stocks have being taken. So, everybody lives, but life is less sparkly, things break down faster, and, as happened in the [Rocky and Bullwinkle Fractured Fairy Tales cartoon](https://www.brownielocks.com/kingmidas.html), we all start bartering with turnips. ]

[Question] [ I've noticed in recent scifi shows/movies such as the Expanse or Star Trek that the lighting inside spaceships have two characteristics: * Punishingly blue lighting * Dark/dimmed miscellaneous lighting everywhere else This doesn't seem useful or practical, but it does make me wonder what lighting could we expect in modern or near-future spacecraft? On the ISS, for example, the space station seems to illuminate a normal, white light in the main hallways or gathering areas. This is done (I presume) for easy maintenance, among other reasons. So darkening your spaceship wouldn't make sense unless you're trying to conserve power. Also, from my understanding, warm colors are easier on human eyes. Further, blue lighting would require more power than colors such as yellow or red, so why not design spaceships with that sort of lighting? Better yet, what sort of light bulbs should be used on a modern or near-futuristic spaceship? LEDs? Incandescent? Something else? [Answer] # LEDs From [Wikipedia](https://en.wikipedia.org/wiki/Incandescent_light_bulb): > > Incandescent bulbs are much less efficient than other types of electric lighting; incandescent bulbs convert less than 5% of the energy they use into visible light, with standard light bulbs averaging about 2.2%. The remaining energy is converted into heat. The luminous efficacy of a typical incandescent bulb is 16 lumens per watt, compared with 60 lm/W for a compact fluorescent bulb or 150 lm/W for some white LED lamps. > > > And if you visit the other links in the page you will have (note that there are several values per type due technological advances and quality): * [Incandescent bulbs](https://en.wikipedia.org/wiki/Incandescent_light_bulb): 10-13.4-16-17 lm/W. 750-1.000-2.500 hours. + Tugsten: 12.6-14.5-17.5 lm/W. + Glass halogen: 16 lm/W. + Quartz halogen: 24 lm/W. * [Fluorescent lamp](https://en.wikipedia.org/wiki/Fluorescent_lamp): 50-60-100 lm/W. 9.000-20.000-30.000-40.000-90.000 hours. * [Compact fluorescent lamp](https://en.wikipedia.org/wiki/Compact_fluorescent_lamp): 50-60-70 lm/W. 6.000-15.000 hours. * [Metal halide lamp](https://en.wikipedia.org/wiki/Metal-halide_lamp): 75-100 lm/W. 6.000-15.000 hours. * [Sodium vapor lamp](https://en.wikipedia.org/wiki/Sodium-vapor_lamp): + [Low pressure sodium lamps](https://en.wikipedia.org/wiki/Sodium-vapor_lamp#Low-pressure_sodium): 100-206 lm/W. 18.000 hours. + [High pressure sodium lamps](https://en.wikipedia.org/wiki/Sodium-vapor_lamp#High-pressure_sodium): 100-150 lm/W. 20.000 hours. * [LED lamp](https://en.wikipedia.org/wiki/LED_lamp): 150-300 lm/W. 15.000 hours. From this list you can see very good candidates: * Fluorescent lamps (average light but very durable); * Sodium vapour lamp (above average light and quite durable); * And LED lamp (very high light and a bit less durable) However, can you guess which bad property fluorescent and sodium vapour lamps have that LEDs don't have? They have a warmup time: * Fluorescent lamps need some seconds of warmup only, but they need an external device (starters) in order to turn on, and that devices need much more maintentance that the lamp itself. Also, they need a "cooldown" time between each cycle otherwise they lose their long lifespan quickly. * Sodium vapour lamps need almost 5 minutes of warmup, also they produce some heat. Even more, both lamps are fragile and can be broken easily with an impact or quick movement from the ship itself. **LEDs lamps don't have these disadvantages.** They neither have warm up nor cooldown time. Also, they aren't fragile. They are very small and produce a lot of light. Due to their size, you can store thousands of them together and they won't break. ## Color - majority white. Then, other colours. This is much more difficult to answer. If you are talking about energy consumption: [](https://i.stack.imgur.com/zBQ6u.png) It must be red. If you are talking about psychology you could read [this investigation](https://researchbank.rmit.edu.au/eserv/rmit:6262/Abbas.pdf) of 134 pages... I won't do that so I've looked at other places. I'm quite sure someone will disagree with this description about colours, but this was my best attempt searching over the internet: * **Red:** Increase heart beating rate, blood pressure and breathing rate, muscular tension, excitation, and desire, even hunger. It can increase aggressive reactions and comfort. * **Orange:** Increase recreation, mobility, vitality. Estimule breathing and relax. May increase hunger. * **Yellow:** Increase happiness and mood. Increase sight, mental activity, creativity and metabolism. Too much yellow can anger people easily. * **Green:** Its sedative and help to sleep calmly. Decrease blood pressure, beating heart rate and stress. * **Blue:** Decrease impulsivity. Make you more calm, quiet, peaceful and help to wake up. Increase blood pressure, reduce hearting rate and body temperature, and give you a tonic effect. This colour could increase productivity in workplaces. * **Purple:** Increase resistance on muscles and tissues. Decrease sadness and fear but its a melancholic colour (and ambiguous). * **White:** Increase happiness, clarity and produce a cleanness feeling. Also, make places more widen and luminous but also cold and alone. I would use the different colour for different kinds of rooms. I would suggest as a "default" colour white because any colour (less white) always makes more difficult to see another colour. Also, spaceships are small, and white colour makes things widen and clean. * **For bedrooms**, I would recommend green or blue, maybe a combination of both (furniture of a colour and lights of another one). **EDIT:** [Orpheus](https://worldbuilding.stackexchange.com/users/44516/orphevs) on comment has said it seems that green and blue can difficult sleep because they are also morning colours, even they can produce cardiac problems. So I would recommend instead a colour like white because it doesn't help to sleep, but it makes your bedroom/quarter bigger and cleaner. * **For passages** white, because makes everything bigger and clean. * **For maintenance, fixing or alert** something white, because it makes sight very clear, and in an intense light it keeps anyone awake. * **For working stations** blue and white because it's relaxing and keeps you awake. Maybe blue furniture/machines and white light, so you can see clearly. * **For night mode** are several options: + Faint warm orange colour, because even in low quantities you can see something and its resemble dawn on Earth, which psychologically induces calm and sleep. + Dark red, because of an effect that I'll discuss below. * **For nocturnal shift:** blue, because it keeps people calm and awake. The absence of blue produces sleep. * **For failure** red because in any moment power (and lights) can shut down. The [Purkinje effect](https://en.wikipedia.org/wiki/Purkinje_effect) states that in a low amount of light, our eyes can't distinguish red easily, but blue and green, that is why in low-light environments we can't see bright red, only brights blue and green. So in a low-light environment, the red light won't be bright nor annoy your eyes, so it'll be easier for your eyes to adapt to darkness. Higher clarity for us but lower stress for our eyes can be provided with red, even intense. > > The insensitivity of rods to long-wavelength light has led to the use of red lights under certain special circumstances – for example, in the control rooms of submarines, in research laboratories, aircraft, or during naked-eye astronomy. > > Under conditions where it is desirable to have both the photopic and scotopic systems active, red lights provide a solution. Submarines are well lit to facilitate the vision of the crew members working there, but the control room must be lit differently to allow crew members to read instrument panels yet remain dark adjusted. By using red lights, or wearing red goggles, the cones can receive enough light to provide photopic vision (namely the high-acuity vision required for reading). The rods are not saturated by the bright red light because they are not sensitive to long-wavelength light, so the crew members remain dark adapted. Similarly, airplane cockpits use red lights so pilots can read their instruments and maps while maintaining night vision to see outside the aircraft. > > > --- [@Joe bloggs](https://worldbuilding.stackexchange.com/users/9887/joe-bloggs) commented that lamps should be connected with the central system, so anyone, when they want, can modify the colour or intensity according to their taste. Light could be modified in the control room, using the control panels in each room, or simply with an app on your portable device. Obviously, LED lamps that are able to change their colour are more expensive than normal ones because they are made of 3 LEDs (red, blue and green) but I think the benefits are greater than the cost in this case. Finally, [@user71659](https://worldbuilding.stackexchange.com/users/44004/user71659) suggested in a comment that LEDs are vulnerable to [radiation and high energy particle damage](https://en.wikipedia.org/wiki/Galileo_(spacecraft)#Tape_recorder_anomalies_and_remote_repair) but I don't think it would be a problem because a crewed ship should already be shielded for radiation, otherwise people could get sick. Also, in the future maybe it could be possible to make more resistant LED technology. Well, like I said it was quite probable that I would receive comments! [Answer] Human eyesight under normal light levels (say, cloudless daylight) can receive and process a very wide array of color and contrast. However, where contrast is more important than color, we rely on the [Purkinje Effect](https://en.wikipedia.org/wiki/Purkinje_effect). > > The Purkinje effect (sometimes called the Purkinje shift) is the tendency for the peak luminance sensitivity of the human eye to shift toward the blue end of the color spectrum at low illumination levels as part of dark adaptation. The effect is named after the Czech anatomist Jan Evangelista Purkyně. > > > This effect introduces a difference in color contrast under different levels of illumination. For instance, in bright sunlight, geranium flowers appear bright red against the dull green of their leaves, or adjacent blue flowers, but in the same scene viewed at dusk, the contrast is reversed, with the red petals appearing a dark red or black, and the leaves and blue petals appearing relatively bright. > > > The sensitivity to light in scotopic vision varies with wavelength, though the perception is essentially black-and-white. The Purkinje shift is the relation between the absorption maximum of rhodopsin, reaching a maximum at about 500 nm, and that of the opsins in the long-wavelength and medium-wavelength cones that dominate in photopic vision, about 555 nm. > > > **Wait... that said blue, why do submarines/airlines/etc use red?** The goal is low-stress/high-clarity. This means lowering the light level, which shifts the eyesight to favor blues (short wavelength colors). But we need to compensate for that, so we use red lights (long wavelength colors). This lowers the stress while maintaining the clarity. From the same source: > > Under conditions where it is desirable to have both the photopic and scotopic systems active, red lights provide a solution. Submarines are well lit to facilitate the vision of the crew members working there, but the control room must be lit differently to allow crew members to read instrument panels yet remain dark adjusted. By using red lights, or wearing red goggles, the cones can receive enough light to provide photopic vision (namely the high-acuity vision required for reading). The rods are not saturated by the bright red light because they are not sensitive to long-wavelength light, so the crew members remain dark adapted. Similarly, airplane cockpits use red lights so pilots can read their instruments and maps while maintaining night vision to see outside the aircraft. > > > **But when I watch Star Trek, the lights are blue and bright, what gives?** Generally, blue light is avoided because it causes [problems with sleep patterns](https://www.livescience.com/53874-blue-light-sleep.html). However, blue light will be used to illuminate underwater [because it transmits a whole lot better underwater than red](https://manoa.hawaii.edu/exploringourfluidearth/physical/ocean-depths/light-ocean). Therefore, in cases where people need to see (for example) the ocean floor through a window and their instruments, they'll sometimes use dim blue lighting to see both. **But, does that explain Star Trek?** Nope! Hollywood uses lighting for dramatic effect. It has absolutely nothing to do with reality. They know that red and blue lights are often used in "combat" situations and so they'll use a change of lighting to create the emotional effect for shifting scenes (danger, Will Robinson!). The color isn't that important to them, the change in color is. If they use red it's only due to its recognizability as a "combat mode" color. But you'll see others as well. [Answer] Ill answer for modern space craft that actually fly. As for futuristic stuff, the skys the limit. [This NASA presentation](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160001038.pdf) has all the answers as to whats used on the ISS > > Electro-Magnetic Interference shielded fluorescent lamps, with a > corrected color temperature of 4500K are currently used for interior > lighting. > > > Generally speaking spacecraft component design focuses on reliability, weight, and power draw in this case. Incandescent bulbs have a relatively fragile filament making them not so great for intense forces experienced during lift off. They also have a [relatively low life spa](http://www.usailighting.com/stuff/contentmgr/files/1/92ffeb328de0f4878257999e7d46d6e4/misc/lighting_comparison_chart.pdf)n when compared with LED's or Florescent bulbs meaning your gonna need to haul more of them up with you per mission profile. [NASA is exploring LED's](https://www.nasa.gov/mission_pages/station/research/experiments/651.html) and there are plans to bring them to the space station. The lighting you are talking about is not practical for say, a press photo, or maybe daily work but the ISS is built to do research and if the task calls for soft blue light it may very well be lit that way at any given time. [At night the ISS is actually lit in a green tone.](https://gajitz.com/space-noir-hauntingly-dim-photos-inside-the-iss-at-night/) [Answer] ### LEDs LEDs are currently the most energy efficient readily available lighting system. Better things may come along, but the reason you read about fluorescent light bulbs in older novels is because they were the most efficient **at the time the story was written**. Wait a minute, we have fusion/warp/antimatter/etc. drive, why does power use matter? It doesn't matter much when you are in warp drive and all systems are working 100%. But when your warp core is overloaded and taken offline and your impulse engines have been damaged by enemy fire and your shields are down, you do **NOT** want to have use any more energy than absolutely necessary for lighting. LEDs are also more durable than incandescent and fluorescent lights. Some LEDs have glass covers, but that is often for compatibility with the look and/or form factor or older bulb types. But LEDs are themselves solid state devices and do not need to be inside a vacuum or any special gas mixture. That makes them more durable than other types of lighting, which is important when you get hit by phasers. In addition, LEDs can have multiple-color and dimmable (typically via PWM, but that doesn't matter for your story) capabilities. That allows for: ### Sleep vs. Wake Time Dimming, and possibly some color variation, is great for sleep time on ships. The nice thing about LEDs is you can do all this with one set of fixtures and adjust electronically. Emergency - turn everything on full brightness instantly! ### White, most of the time You want bright, white light for best visibility for reading and working in most cases. Any non-white color will normally make some other colors hard to see. Darkrooms used to use red light because typical film was less sensitive to red light. But for normal use, white light of some variant (cool vs. warm vs. "sunlight") is definitely better than blue or green or red. There are some exceptions though. In addition to the great theatrical effects, going to red for "red alert" makes a lot of sense. A low red light - enough to safely run to your battle stations - is all you need. The individual consoles will be lit up as needed, but keeping the overall light level relatively low may actually help the crew focus on their tasks instead of looking around at everyone else. [Answer] Light color doesn't just effect mood, it also effects visual accuity. I use soft white (probably 2700K) in my home, but 6500K in my shop and outdoor lighting. The 6500K light reveals a lot more detail at the same wattage, particularly when lighting conditions are low. Which is to say, if you want to see a floating hex nut before it smacks you in the noggin', hotter lighting colors are better. As for color-wheel colors, I would think workspaces and living spaces would have different coloring. But people are weird about that stuff. If I remember correctly, a color study was made to find the LEAST visible color for the F119 Stealth Fighter. It turns out black wasn't it. But fighter pilots "don't fly pastel colored airplanes." was a good enough reason for painting it black. The commodity value of pigments in space would be quite dear, and safety would be a factor. You sure wouldn't want anything that can spall flake or drip. My expectation is that on a big ship coloring would be handled as a rolled tapes of various widths that could be requisitioned by the shop on a per crewmember basis. So probably coloring would be mostly accomidated by picture borders and the like. Some interior spaces might really end up looking like a picture wall in a resturant or a kindergarden. A total hodgepodge of little things so that people can identify and feel appreciated. As for mood lighting, probably a living and working light frequency would be available in all spaces, with perhaps a voice command for switching between. Adding fancy pleasure cruise colors would probably be an extreme luxury. I don't think color selection with statistical models is the greatest idea. The people who go nuts, are generally going to be the outliers. So it isn't about finding one "best" color everyone, so much as finding an economical way of accomidating the needs of the all of indevidual crewpersons safely. [Answer] You would really want [full-spectrum lighting, or daylight bulbs](https://www.raysace.com/the-difference-between-full-spectrum-bulbs-and-daylight-bulbs/) on your space ship, especially if intended for large scale or long term use. You might have people wanting other kinds of lights in specific places, or have alternate lighting for specific scenarios, but there would be a lot that is full-spectrum lighting by default. Humans are well adapted to sunlight, and for more than just vision - look at [lightboxes](https://verilux.com/pages/full-spectrum-light) available for [Seasonal Affect Disorder (SAD)](https://en.wikipedia.org/wiki/Seasonal_affective_disorder) or the use of [phytotherapy](https://en.wikipedia.org/wiki/Phototherapy) to treat depression. It is also used to regulate sleep cycles in case of disorders. Not to mention the [health value](https://en.wikipedia.org/wiki/Sunlight#Effects_on_human_health) of sunlight for Vitamin D production, melatonin synthesis, and some [skin disorders](https://en.wikipedia.org/wiki/Sunlight#Sunbathing) like psoriasis. You are also likely to find full spectrum light useful for food production - [light for growing plants](https://www.gardeners.com/how-to/how-to-choose-a-grow-light/5020.html), for hydroponics, etc. Not to mention there may well be a purely psychological effect (to go with the physical effects) to having something like sunlight available. It is possible the full-spectrum lighting will only be available in select areas, for those specific health uses, but it's just as likely that full-spectrum lighting will found in common areas, to best encourage sufficient exposure for most people. And by the time spaceships are quite common, there may be other reasons (known *or* assumed) to encourage access to sunlight-like lighting. [Answer] So the other answers pretty much have this covered quite well on the type of light bulb. However, on the colour issue, [NASA's answer](https://www.theverge.com/platform/amp/2012/12/17/3775978/nasa-to-test-led-light-system-on-the-ISS) is simple: it varies. As the other answers have noted, different light frequencies have different effects on humans, and depending on the desired effect we want the lighting is changed. On the ISS, they use **blue light** to stimulate the astronauts and simulate daytime, **white light** as a transition, and **red light** for sleep. [Answer] I doubt whether there would ever be humans on spaceships -- except perhaps the occasional showpiece carried out for PR purposes-- so probably no need for lights. ]

[Question] [ Suppose humans have developed the technology to travel between star systems. This might be some science-fiction method like warp drive, jump drive, peanut butter drive, hyperspace drive or whatever, or something vaguely scientific like the [Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive). The specifics of the means of propulsion doesn't matter here. Now, a spacecraft carrying a number of humans-as-we-know-them has settled into orbit around an extrasolar planet, and the people onboard have determined that the environment on at least a part of the planet's surface is suitable for human life (about right oxygen content, not too hot, not too cold, ...). The next step is to determine if humans could actually *live* on that planet, as opposed to just briefly visiting. One of the things that often get handwaved away in science-*fiction* is the ability of colonizers to eat and process foodstuffs found on other planets. Given how many different possibilities there are for how amino acids could be combined, and how those can form protein chains, it seems dubious that humans would be able to pick up some alien foodstuff that has evolved on some far-away planet, eat it, and derive any significant (if indeed any) nutritional value from it. We just haven't had any reason to evolve that ability. **Would humans be able to derive nutrition from alien foodstuffs?** *If yes:* **Why?** *If no:* **What would be the main complicating factors?** I'm tagging this *reality-check* because we don't know much of anything about what alien foodstuffs might actually be like, but *bonus points for answers drawing validly from known sciences.* (Basically, as much as possible, treat this question as if it were tagged *science-based*, or *hard-science* if you are able to.) I believe this is **not** a duplicate of [Compatible biochemistry, or not?](https://worldbuilding.stackexchange.com/q/12493/29) (hat tip to Frostfyre for finding that one) because that question appears to posit that the biochemistry is compatible and asks if that implies that there is biochemistry compatibility both ways (alien life being able to eat Earth biomass *implying* that Earth life should be able to eat the alien biomass), whereas this question asks about biochemistry compatibility in the first place. [Answer] The answer is "it's possible, but VERY unlikely". There's a lot that goes into this, but the short answer is that there's no guarantee the proteins that developed on this planet will be compatible with our biochemistry due to a little bitch of a thing called [chirality](https://en.wikipedia.org/wiki/Chirality#Chemistry). And even if you get lucky and find a planet with compatible proteins (possible but definitely not probable), there's a lot on our own planet we can't eat, and it's very likely that most of the food there would contain elements or chemical compounds poisonous to use due to having evolved under different circumstances than life on Earth. That being said, it's not entirely a lost cause. As long as you've tested the food and are certain it's not poisonous, even alien organisms with reverse chirality proteins can provide you with simpler nutrients like sugar and carbohydrates (maybe fat too?). You still won't be able to digest parts of it and you won't get any of those life-sustaining proteins, but there's no reason an alien fruit couldn't be as sweet and juicy as Earth fruit. Alien ethanol (a.k.a space hooch) is also possible with some fermenting and proper processing. So, can you eat alien food? Yes and no. Assuming it's not poisonous, you can eat it and maybe even get some simple sugars and carbs out of it, but don't expect to get any of your daily protein from it (or even completely digest it for that matter). [Answer] Most plant food on Earth won't sustain people. That's why people were hunters before farmers. Meat, at least earth-meat, is easy to digest in almost every form. Few plants have anything edible about them, as a defence mechanism. Consider the Apple Tree, it only produces apples specifically so that animals/birds eat them, walk somewhere else, and poop out the seed, thus propitiating their species. And this is only in the fruit season. The leaves, the bark, the sap, little to no nutritional value, and many actually have negative caloric values; they cost more to digest than they provide. When people figured out that hey, there are a couple fruiting-body plants out there (corn, fruits, vegetables) that provide nutrition that they don't have to risk their lives for, we made sure to make A LOT OF THEM. In untouched nature they are very rare. Grass is likely the only edible thing you'll find in the fall in any place that has no people in it. So on an Alien world, if it had cultivated a civilization, maybe they've spread the "edible" food (edible to them, whether that means to us I can't say), but otherwise the entire world is designed to sustain life -- to prevent being eaten. Carrots and the like survived by hiding underground -- that protected them from above-ground threats. So animals learned to dig and find them. Many foods that do have edible mass, at least using Earth again for examples, contain poisons, UNLESS eating them is part of the propagation cycle. Consider Mushrooms for example. They don't need you to eat them to spread, and most all of them are poison to people. [Answer] Let's start by changing the question, and later apply the answer to this to the question as asked: Instead of a different planet, let's imagine our explorers are actually visiting our own planet Earth, but in a different eon. Say, the Triassic Age, to pick one at random. Now, ask the same question: Can they eat the plantlife? In theory, framing the question this way should make it easier to answer: We're removing all issues of alien DNA or chirality, etc. But in my view, the answer would still be a resounding 'No'. The Triassic Age pre-dates the appearance of flowering plants, so you would have no fruit. There's also no grass species yet at this point. So at a stroke, we've lost the vast bulk of plants that humans like to eat. There are, of course, plenty of plants in the Triassic, but none of them are familiar, and most of them will be inedible. You would have to spend a very long time doing a careful analysis of the plants that do exist, analysing them for nutritional value and for toxins (and there are likely to be toxins that you haven't seen before). Given enough time, it's possible you might find a few species that are edible; possibly including the distance ancestors of some of the food plants we know today. But it won't be easy; my guess is that your colony will not survive. And this is on our own planet. Phrase the question on a different planet, and the issues become orders of magnitude more difficult. There may be out-right compatibility issues such as chirality or alien DNA. But even if the local life forms are completely compatible with us in that respect, they are still likely to have evolved their own entirely unique toxins and bio-defences to avoid predation, and as we've never had to deal with them, humans will be totally unable to cope. [Answer] The short answer is, "it depends": * If you subscribe to any [Panspermia](https://en.wikipedia.org/wiki/Panspermia) ideas, then the answer is a maybe to probably. If you go with the more aggressive Panspermia approach where "all these worlds were once settled by humans in the previous galactic empire that crumbled into dust" then the answer moves up to yes. Terraforming has been done and random evolutionary chemistry is toast. Everything, right down to the microbes, is compatible. * If you view a new world where life evolved from scratch, with random chemistry, cellular structures, and biome then you are not long for the world. You would be lucky to survive a breath of air or touch of a plant, much less trying to stick something into mortal combat with the colony creature that is our stomach. [Answer] Glucose is a simple molecule and a good energy store. I wouldn't have any trouble with believing in alien biochemistries that used it, and the various saccharides built up from it. Going up the complexity scale to fats and proteins, things start getting progressively less plausible. [Answer] Assuming that it is a colony ship, it should already be extensively using Hydroponics. As elements are universal, you should still be able to use the alien plant life as a composting agent in order to grow Earth plants on the ground, and use the existing Hydroponics farms on the ship to supplement the food source until a proper crop rotation can be established. Why settle for alien food that is yet to be proven safe to eat when you can just eat Earth stuff for many generations to come. Once you've done the science to determine the nutrition or use of alien plant life then you can start cultivating those plants. If you're worried about the alien compost making the food toxic, then it's not a huge leap that a society that can make an FTL drive can have a relatively inexpensive way of dividing up matter into it's base elements. [Answer] There are only so many amino acids, and they can only be combined in so many different ways. It is possible that humans could digest foodstuffs found on an alien planet. It is not probable though. Digestive enzymes would be the limiting factor. There are foodstuffs here on earth that humans cannot eat. Like high-cellulose vegetation. Humans are only designed to break down specific compounds. And even among humans there are those who cannot break down commonly consumed compounds like lactose. [Answer] Assuming humans would survive the trillions of new viruses long enough to worry about grabbing dinner then I would say maybe, with a lot of work. The physical elements of life on an alien world would pretty much be the same (Hydrogen, Carbon, Oxygen, etc) so there is always the possibility of taking alien life and breaking it down into its raw elements and regrowing it into something edible. However the constraints of doing this are numerous. Even if we assume that we have abundant energy, complex machines, a willing robot work force, a willing alien world that is happy for us to eat it, etc, the process would be time consuming and probably not very scale-able. The infrastructure needed to support and feed a city of a million could take years to develop. Also if we assume we land on a world as complex and diverse as our own, there would probably be something we could eat--or find genetically interesting--but the problem would be finding it. Think about the Amazon. There are millions of different plants and animals hidden in there but finding them is a problem. The logistics of putting together an proper research time to find, catalogue, test and taste every species on a new planet would be staggering. In the end it might be cheaper just to fly back to Earth for lunch (supplies.) [Answer] Humans are good at dealing with substances which occur in nature, we are tolerant of them. In comparison we tend to be very intolerant of things we haven't encountered much on our evolutionary journey to the point that minuscule amounts tend to be very harmful or even fatal. Consider as examples of this simple elements like lead or mercury which are extremely toxic to us. Given this, it seems likely that unless the alien life is pretty much identical to us at a biochemical level, the best case scenario is probably just surviving ingesting any of it, never mind deriving any sustenance. [Answer] Given that we are only able to digest a limited number of compounds it's unlikely that humans would be able to digest the compounds of life on another planet. Also, considering that complex molecules that we aren't evolved to digest tend to be toxic, an alien life form, even if it was not poisonous to most other life on its planet, might be poisonous for humans to eat. If one were to kill and eat an alien "animal" for instance one might be in a worse position than if he/she hadn't eaten the alien "meat", as not only would the alien "meat" be unlikely to provide nutritional value, but it's likely it would cause the person to get sick or even to die from ingesting something that is poisonous to humans. [Answer] I'd suggest that humans would have been modified by this point to be capable of 'ignoring.' eating normally or reconstituting on the fly any given foodstuff they cam into contact with. Growing and carrying food around is immensely wasteful, no interplanetary colony ship would be carrying hydroponics or any such thing. Rather they'd be taking one of two approaches: Firstly: To make use of communal devices that breakdown and reconstitute any given material into it's component parts and reconstitute in any given desired format. That isn't star trek science, it's a given that this is possible as we already do it. Secondly: To do essentially the same but with individual internalized devices (biological or otherwise.) The second approach would clearly require more effort, but I propose that it would be a device/modification that every and all interstellar travellers would make use of, being as it with one shot renders starvation and gastric poisoning implausible. Eating for the sake of taste would therefore probably become a niche interest/industry, and the 'compatibility' is then a given as you're not caring about the availability or providence of a given complex molecule. Other than that, the human body is designed to take in lots of mass and make use of what it can, on the assumption that it cannot or (in any particular instance) does not use most of it. We could suppose that in an alien ecology a person might have to eat several times the volume to gain anything like the same nutritional benefit, or the compounds might take longer to break down in the stomach and not actually be absorbed by the time bowel movements pass them out (same with many terrestrial foods.) It's a mistake to imagine that everything we eat is absorbed by the body, or that everything we pass out cannot be used. It's a very very very far from perfect process even given foodstuffs we're relatively well adjusted to absorbing. The opposite can also be true and certain chemicals might be more abundant in alien foodstuffs than in terrestrial options, even should those chains perform a quite different function in the alien organism. A given protein does not do x or stop y in every conceivable organic architecture, rather it's inclusion and operation is dependent upon the rest of the organism's constituent parts & it's environment. The likelihood of one or t'other or any alternative is impossible to calculate of course, as any question of "would non-terran life be or do z or f" is. ]

[Question] [ The idea is for some people in a post-apocalyptic future to find these bunkers/vaults and be able to turn on the computers and charge the cellphones. How many years could the equipment last if they were stored in very good conditions (no sun light, no humidity, all covered in plastic or inside boxes)? 10 years? 100 years? There are already some related questions ([this one specific about cars](https://worldbuilding.stackexchange.com/questions/81560/for-how-long-after-an-apocalypse-would-modern-cars-remain-usable)), but in most of them the objects where abandoned in the environment or left behind without being properly stored. [Answer] There are three really big problem components for long term storage of computer hardware, batteries, flash memory, and electrolytic capacitors. While there are other components that can fail in long-term storage, most of them can be kept working if the storage environment is ideal. These three, however, will pretty reliably fail after a reasonably short period of time independent of the environment they are kept in. In particular: * Batteries: Varies, but generally not very long. Most batteries have a shelf life of at best a few years when left unused. The CMOS RTC battery in most computers won't be much of an issue barring some potentially weird configurations that rely on firmware settings. The batteries in phones or laptops however are another story. For those, you'll be lucky if they work at all after about 5 years of being unused. From a safety perspective, you should also be replacing (or at least reconditioning) any batteries in such a device before attempting to use it, failure there tends to be catastrophic and very dangerous. In some cases, you *might* be able to get away with having a really exotic type of battery that can safely be stored for long periods of time (Silver-Air batteries come to mind, but they're expensive, not rechargeable, and still only last at most a few years). You might also make things better by storing the device with the battery fully discharged (most rechargeable batteries have a longer shelf-life if stored discharged), but that probably also won't extend things by much. * Flash storage: Theoretically indefinite if there's no hard radiation, but it won't retain data past a few years without special efforts taken to do so. Flash memory is insanely durable when not being used. About the only things that can reliably make it stop working are long term exposure to hard radiation, extreme thermal stress, extreme heat, or just plain physically destroying it. However, it's actually not really all that good for long term data storage. The reason for this relates to how flash memory works. In short, flash memory stores data by trapping an electrical charge on an otherwise electrically isolated bit of conductive material. Doing this requires pushing electrons across a layer of insulating material, which degrades the insulating material over time (this is why flash memory is write-limited), causing the electrical charge to slowly leak out. For flash memory seeing active usage, this isn't much of an issue as things will get rewritten before it becomes an issue. For flash memory in archival storage however, this puts an upper limit on how long your data will last. For good quality SLC NAND flash, this limit is estimated to be somewhere around 5 years. For the cheap MLC NAND flash used in most devices these days, it's usually only 2-3 years. There's not really any practical way around this except not using flash memory, but most forms of storage media do have some type of long-term degradation they have to deal with. * Electrolytic capacitors: At most 15 years. These are mostly used for power handling in computers and other devices. The issue with them is that they use a gel as one of the two electrodes, and if this gel dries out or leaks out, the capacitor will stop working (and if it leaks, it may damage other components when you try to power on the device). Even if kept in otherwise perfect conditions, the sealing material will deteriorate over time, which for current designs puts a functional upper limit of about 15 years on their life expectancy. You can obviously work around this by just not using electrolytic capacitors (and some phones don't for exactly this reason), but it's non-trivial to figure out if an arbitrary system uses them or not, and most of the alternatives come with their own issues. [Answer] There are two primary parts you need to consider the shelf life of for these devices * Magnetic storage * The battery The general theme of this is that while magnetic storage shelf life can be [measured in decades](https://www.pcworld.com/article/2984597/storage/hard-core-data-preservation-the-best-media-and-methods-for-archiving-your-data.html). LiPo battery shelf life is [measured in years](https://electronics.stackexchange.com/questions/150818/shelf-life-of-a-lithium-polymer-battery). The real limiting factor here is the LiPo batteries. They don't like being overcharged, or fully discharged, or shocked, or not used, or overused. Their general reaction to all of these things [is to explode](https://electronics.stackexchange.com/questions/230155/why-is-there-so-much-fear-surrounding-lipo-batteries). So while visually they may be in pristine condition, the chances of being able to get any of these devices to run is minimal after anything over a decade of storage. --- There's an extra factor here that needs to be considered * Solid state storage Unfortunately this is currently an unknown quantity. As a fairly new and rapidly changing technology, lifespan estimates range from decay starting in only 7 days when left unpowered to lasting over 300 years with steady use. [Answer] One more cause of failure to note are “Tin Whiskers”. <https://en.wikipedia.org/wiki/Whisker_(metallurgy)> At present, any lead-free solder used will form tin/zinc/silver whiskers at some unpredictable time in the future. These hairs are a few micrometers across and once started can grow as fast as 1mm per year. Eventually the whiskers will bridge pins and traces on the circuit board and destroy the device. There has been a large amount of research into using conformal coatings to prevent this growth, but the massive pressure these growths generate in tiny pinpoint locations has been able to eventually penetrate or lift all coatings that have been tested. This brings up an interesting side of your question. Electronics built before the mid-2000s may not have this type of failure for centuries, while electronics built after the lead soldier ban are unlikely to last much beyond 20 years. However, safety critical and space flight circuits are currently excepted from the ban. This means computers in cars, airplanes, satellites, and power plants are allowed to use lead soldier and will not suffer from this problem. [Answer] Another issue to consider is the overall system aspect of cell phones. They don't work without a cell tower network, including functioning computers to keep track of everything. So cell phones simply won't work at all once the external tech has died. [Answer] I would think that any computer equipment (PC, notebook, phone) would last pretty well, as long as: * Any battery (including e.g. a coin-cell motherboard battery) was removed * It didn't rust (temperature and humidity were low) * Doesn't rely on EPROM holding state (it will degrade in a decade or so) * The plastics didn't degrade too much * Any capacitors didn't leak So if the computers were intentionally stored for long-term survival, and there were instructions on how to put them back together, build new batteries, etc. then they could last for.. let's say multiple decades but probably not much longer than 100-150 years. As for any data, the storage medium would need to be carefully considered. * USB sticks, flash media. - maybe 10 years if you're lucky * Other solid state media - lasts a few decades ([Here's one that supposedly works for 100 years though](https://www.pcworld.com/article/199672/sandisks_sd_card_can_store_data_for_100_years.html)) * Magnetic tape - [about the same](https://en.wikipedia.org/wiki/Media_preservation) * Spinning-rust hard drives - [maybe 100 years](https://superuser.com/questions/284427/how-much-time-until-an-unused-hard-drive-loses-its-data), allowing for some data loss and degradation of the moving parts * Optical storage - Archive-grade BluRays [claim](https://www.zdnet.com/article/the-1000-year-dvd-is-here/) [up to 1000 years](https://www.amazon.co.uk/Years-Archival-Verbatim-M-Disc-Blu-ray/dp/B01B99WUR6). [Answer] If the devices were deliberately built to last, the story could be quite different. If you are willing to make significant sacrifices and accept high cost, both in R&D and materials - to begin with, optimize for durability, not performance. * Do not use electrolytic capacitors or rechargeable batteries. * Store read-only data in old school ROM. (Not EPROM even, ROM.) * Make all circuits essentially space grade, so not even accumulated background radiation can flip something. * Do not use batteries, instead use some other kind of power source as well as instructions on how to create a power source from scratch. * Provide dry batteries (non-rechargeable) for boot-strapping in the first phase. * Wet batteries but with chemicals stored separately in large vats with instructions on how to activate them? * Use simple LED character displays and small speakers for output instead of relying on normal, complex bitmapped displays. * Provide extensive documentation on all systems, including physical paper (or plastic) on *everything* * Build the same system with different technologies in several versions, from discrete transistors up to ICs with everything in between, so a society can bootstrap and make replicas in ever increasing sophistication. and so on... a bit on a tangent but I thought it was a cool idea. Like a Rosetta stone for computing. [Answer] Atmel ATMega series microcontrollers give 100 year data retention guarantee. This is at regular shelf around 25C. Under better conditions they can last longer and even better performing devices can be built for the purpose. I can see a computer system that will be able to work after several 100 years. LEDs do last for a very long time. Even while working non-stop, I have seen LEDs working for 20+ years. Thus a simple (say 200x100) LED screen could easily last several centuries. Just protect everything from rusting and temperature swings. Unfortunately, batteries will not last that long. There are lithium batteries that can last for 40 years, that is the best I could find. So it would be an issue to power these devices. The best bet could be a mechanical device that can be cranked to supply power to a low power device. Of course this mechanical device should be stored in an airtight storage. [Answer] Just today, may 26, 2022. I turned on a zenith laptop computer that was made in the late 80s and seemed to function as I should have back then. From what I can tell, this is probably the first time it's been turned on in 30 years. Granted, it didn't have batteries, and it's slow and the screen sucks, but as long as the capacitors dont leak, and the HD doesnt bind up, they may work as if not a day has gone by. ]

[Question] [ A thought occurred to me while watching Ender's Game. **Why are these two fleets in space lining up like two armies during the revolutionary war (or pick your war of the musket/volley era)?** Thinking about it further it occurs to me that in basically all sci-fi movies with space combat going on the two sides are lined up on the same plane. (if you have viewing suggestions to the contrary I'd love to watch) I understand why this happens. It is what we are familiar with. Even when you are talking about aerial combat on earth you still have gravity and the ground as an anchor point for battle but not so much in space. **How would the ability to function equally well in 3 dimensions affect combat tactics?** * Assume modern weapons technology (specialized to space as needed) * Any required mobility tech can be included in answers * Defensive technologies that utilize modern tech levels [Answer] Having not seen Ender's Game, I can only comment on the way 3d would affect combat. The answer (at least the way I see it) is that it really depends on the opposing armies and their technology. Currently, if humans went to war in space, we would likely be launching extreme-precision missiles at each other from a long way away, while attempting to shoot down the opposing missiles with point-defense. The reason for this is because "shields" don't exist and our hulls are so thin even small explosions would destroy a craft. In the future, unless science comes up with true energy shields, I can't imagine it being much different. It is so expensive to do anything in space that you would focus everything you had on offense, intelligence, and first-strike capabilities, leaving very little for defense. All that said, if you had defenses such as energy shields that took minutes or longer to break through, even pounding on it with nukes or something, I can see ships easily lining up in formation to help focus fire and minimize their susceptibility to being surrounded and hit from all sides. The line formation (or block formation in space) is really only suited for situations where firepower isn't sufficient to destroy the target immediately. As soon as we started developing, for instance, guns that could reliably and quickly kill enemy soldiers, we abandoned the line formation in favor of more maneuverability. Hence, if our weapons stay more advanced than our defenses, it stands to reason we wouldn't ever go back to using the line formation. All that said, true space combat will likely look nothing like we see in movies. [Answer] Well we do have airplane tactics that do require all 3 dimensions. I also think Kirk used Khan's 2 dimensional search pattern against him. Ender's Game not so much in the movie but in the book, he makes great use of the fact of both 3d and no gravity to win his games. One thing about the last scene where they were lined up, part of the problem was, all the alien ships were trying to protect the planet from the invading fleet. The invading fleet didn't split up because they needed to drive a wedge through the fleet as close as possible to the planet surface. The biggest issue of 3d in combat is you have a larger front to monitor and protect and thus need more 'troops' to build a better net. [Answer] Ships? What? Assumptions: 1. You wish to obliterate an enemies planet 2. You're capable of (near) superlunary travel You accelerate mass (or a number of masses) towards the target planet at near light speed from outside the system. Your target will have very little to no (depending on how close to light speed) chance to detect (by conventional means) these superluminal masses. As soon as these masses hit the atmosphere they will turn it into super heated plasma, or worse. References: 1. <http://en.wikipedia.org/wiki/Relativistic_kill_vehicle> 2. <http://www.projectrho.com/public_html/rocket/spacegunexotic.php> ... and a quote from the latter link ... > > A starship weighing in at 1,500 tons (approximately the weight of a > fully fueled space shuttle sitting on the launchpad) impacting an > earthlike planet at "only" 30 percent of lightspeed will release 1.5 > million megatons of energy -- an explosive force equivalent to 150 > times today's global nuclear arsenal > > > . You're not going to be able to defend against that. [Answer] Well, considering how communication in space would be [pretty](https://worldbuilding.stackexchange.com/questions/484/is-there-a-scientifically-plauseable-faster-than-light-communication-system) [difficult](https://worldbuilding.stackexchange.com/questions/4389/how-would-interstellar-internet-work/4448#4448), I can imagine one great reason for sticking in a line-ish formation. Nowadays, military operations are undertaken with most of the supporting intelligence members, thousands of miles away. Unfortunately, in space, thousands of miles away may only be a few space battleships apart, as they would do well to space themselves well enough so that both powerful enemy weapons and themselves do not do too much damage to them. Because of that, it is possible for the fleet to cluster around a flagship, within which contains all of the supporting members for the fleet. Because the flagship has all of the fleet's command and control, the fleet may then decide to form a semi sphere formation in front of the flagship to best protect it. Another thing to note is that in Ender's Game, the aliens were trying to simply defend their home planet, while the human fleet simply needed to break through and get to the alien planet. As such, that formation sort of makes sense, although a giant rectangular prism formation may have worked better in that scenario [Answer] They would be decided by computers, in completely automated (no tripulation) ships. And the shoting phase would last a few seconds (at most). Then it would take a little while to verify the results. Speeds in space are high (they need to be, if you want to get to anywhere). 1) Imagine you can detect an enemy ship at 10 lightminute distance, that is travelling towards you at half the speed of light. * This means that the enemy is, right now, just 5 minutes light from you! * The Gs needed to change this speed in any significative amount in this time, would be far more destructive to your ship than anything the enemy could launch at you. 2) As soon as you detect him, he detects you (let's say technology levels are equivalent). If he decides at this moment to launch an attack, you won't notice anything until the enemy (and his missiles) are 2.5 minutelight away from you1! When you see the enemy launching a missile against you, it is already almost at your door. 3) Now your defense are evasive maneuvers, after all, the enemy ship probably shot towards your estimated position in 2.5 minutes. Or perhaps the enemy computer acknowledged that and shot towards your more likely escape route... In any case, if your ship is handicapped because it cannot accelerate too much due to the stinky meatbags doing PLOP! at high Gs, then things look grim for you. If your ship has the luck of being fully automated so it has not meatbags in it, it can squeeze all of the power from the engines, and then it may have a chance of survival. Of course, in the immensity of the space the enemy cannot just launch a "rock" and hope that it hits you. The projectile will have thrusters; not to the back to keep its speed but to the sides to steer towards you and counter your evasive maneuvers2. There will be a need to chose the right projectile for the situation (a heavier one will probably ensure a kill on impact, but a lighter one will be way more maneuverable). Also, probably the enemy send you not one but a swarm of projectiles. Due to scattering, lasers could work only as a close range defense. A possible exception would be ultra heavy, extra powered and carefully calibrated laser station in asteroids (or moons) around some strategic point. As for the strategies, if your sensor stations detected a fleet passing by Uranus 3 days ago, and then the fleet was detected again by Jupiter yesterday, you can try to predict the enemy route and, before getting in range, "blind fire" your missiles towards the zone they will pass through. Or sending a load of nuclear weapons so the EMPs disable their electronics. Alternatively, another defense would be seeding zones of space with nanobots that attack enemy ships sensors or hulls, working as minefields. 1 Given that their missile will be smaller than their ships and (probably) harder to detect, that is only an optimistic estimation. 2 A possible point defense would be using lasers to disable the missiles control centers, but that would be operated by computer too. [Answer] Modern air to air combat already occurs beyond the range of sight. The lack of resistance of an atmosphere would allow for combat at extraordinary distances. Armor would be impractical and is already unable to deal with the destructive power of modern weapons. Furthermore there would be little penalty for use of nuclear warheads in deep space. Combat would likely revolve around stealth and the ability to detect your opponent. Whoever detects their opponent first will likely win. In this regard it may be similar to submarine combat [Answer] This happens in media because it's simply what the artists (be they writers, modelers, film-makers, etc) know. Adding the third dimension to combat is a "game-changer" before that phrase became trite from overuse. As we are generally constrained to a flat plain in our daily lives, we get very little experience thinking otherwise. Take a look at air power from WWI-WWII, this very topic comes up. Those who were able to think in three dimensions--from pilots to generals--gained a significant advantage. [Claire Chennault's](http://en.wikipedia.org/wiki/Claire_Lee_Chennault) Flying Tigers had to use 3D thinking as a matter of course: Their P-40 Warhawk was heavily armored (for a plane) but not as nimble as their Japanese counterpart Zeros (as well as the Nates and Oscars to some degree). They had much better dive characteristics, however, so the standard tactic was to use early warning to give the responding squadron time to climb above the approaching Japanese, then dive down upon them relying on the high speed thereby gained to obtain the element of surprise. Also leveraging my Air Force background, Curtis LeMay helped develop the [Combat Box](http://en.wikipedia.org/wiki/Combat_box) formation, a 3D bomber formation. Urban warfare is similar, and the Soviets used it in a gruesome manner (by necessity, in some cases): In Stalingrad, for example, Conscripts were hastily armed and sent into urban combat essentially untrained. Those who survived displayed an innate talent for urban warfare. This includes understanding and use of the 3D battlespace created by cities: Higher floors give a vertical element to attack and defence against troops outside, while stairways and damaged floors provide a vertical element to combat indoors. Much of this is aided by the advent of rapid-fire, highly accurate firearms. Until the advent of cartridge weapons in the mid-1800s, reloading a firearm was a time-consuming operation. Cartridge weapons began regular adoption in the latter 1800s, along with the ability to machine weapons capable of withstanding higher pressures--thus higher velocities, providing greater accuracy. That gives us about 150 years of experience with this sort of combat. Prior to this, relatively short-ranged, low-accuracy, slow-loading firearms had prevailed for around 600 years--with bows and crossbows for centuries before them being similarly slow and inaccurate in all but the hands of trained specialists or in the same volley formations as the black powder weapons required. So coming full circle: For millennia, artwork and warfare has involved *relatively* flat, planar combat due to the difficulty of engaging an opponent beyond touch range before they (or more importantly, their comrades) could engage you even with the ranged weaponry of the period. Call it 3000 years, for simplicity's sake. Suddenly, over 150 years--5% of 3000 years!--we've come into the capability of engaging targets in all directions for more than a brief moment. This is part of what even allows air (and thereby, later, space) combat... and we've ran face-first into it as a wall. Is it any wonder that few beyond those dedicated to 3D warfare have much understanding of it? Few and far between are warriors and fans of such a topic--fewer still are those who can also be counted as artists. TL;DR Version: **Why are these two fleets in space lining up like two armies during the revolutionary war (or pick your war of the musket/volley era)?** Because that's what the artsits providing you with this view have experience with. **How would the ability to function equally well in 3 dimensions affect combat tactics?** Look at air, urban, and (to a lesser degree) submarine warfare, and you'll start to get an idea. [Answer] A principal of naval and air battles is **no reserve**. This is because in a bland environment, the one who shoots the most wins. On earth, clouds, storms, fog, land (as a boundary for air and sea) make it a little complex though usually still very bland. While space has planets, and battles are likely to fought near them (as naval battles generally are to ports), it also is extremely bland. There is a role for maneuver hiding behind moons etc to set traps perhaps. Imagine 6 ships (Red) v's 10 ships (Blue). Assume 50% kill. Round 1 Red kills 3 Blue ships. Blue kills 5 Red ships. Red = 1 and Blue = 7 Round 2 Red 50% chance of killing a Blue ship. Blue destroys the Red fleet. Red = 0 and Blue = 6.5 Tank tacticians use such calculations as well for frontal battles. You would need to keep your fleet together, and at full strength. Asa general rule there is no hiding so kills are going to follow rules of maths. If technology is the same then battles can be predicted. The 3D part is irrelevent (unless the environment becomes complex by being near planets and moons). You can see equally well in all directions, fire equally well in all diections. Attacking from multiple directions will split your fleet, it doesn't help your attack, but if there is mutual assistance with the defensive technology, then it reduces your defence. [Answer] I can do some viewer suggestions,Babylon 5 and New Battlestar Galactic, if you like anime then the Gundam series are place to watch some three dimensional space combat. I think that most space combat in films and television operates on a mixture of air and naval rules, due to a combination of familiarity and laziness. We on earth are accustom to the imagery, the visual dictionary of air and naval engagements, true three dimensional combat with ships spinning on their axis to attack pursuers or making flat turns. Would look utterly foreign to us. Modeling space combat on naval and air combat,especially WWII is a developmental short cut. [Answer] It depends a lot on the situation and the technologies. Near-future would probably look a little like the film *Gravity*, but without the wrong physics. That is, lots of useful satellites and a few manned things are all in Earth orbit, and they can all be pretty easily destroyed by getting hit with anything, including fragments from impacts. At a higher level of technology and military development, where there are actual fleets of maneuverable military ships, but still we only have missiles, projectiles, and beam weapons, then it depends on the balance of abilities between detection, identification, communication, jamming, targeting, effective weapon range, unit acceleration, and interception or other defensive systems (e.g. decoys). So: * First you want to detect your enemy and know where and what they are while misleading your enemy about the same things. * Then you want to mislead your enemy into wasting their resources and making theirs vulnerable, while avoiding exposing yours, and accurately deploying your own offensive resources to eliminate theirs as soon as possible. * Part of that will involve maintaining your communications with your own units, while not giving away their locations or what you are communicating, while possibly interfering with or locating or even decoding enemy communications. This could get quite complex and involve decoys, relays, jamming broadcasts, encryption, false messages, and non-broadcast communications such as directed (e.g. laser) signals, as well as pre-arranged plans, and discovery/espionage/study/deception around those plans. * Defensive deployments can involve keeping your forces out of range, in undetected locations, constantly on changing trajectories, and the choice of whether to group them for mutual support inside screening units/devices, or to keep them widely distributed so they can't all be surprised or engaged at once. Concentration of force may need to be balanced against exposure, particularly when it's easier to destroy targets than to protect them, and when near misses or fragments from hits endanger other nearby ships. * A major difference with space maneuvers as opposed to Earth maneuvers is that the vacuum of space allows great velocities to be built up, which can be used for high-speed attacks, or luring enemy forces far out of position, and generally results in a trade-off between high velocities and over-commitment to a certain vector. * With current or near-future technology, there are also major trade-offs between speed, thrust, fuel carried, and inertia. I.e. there's no particular limit on the amount of fuel that can be carried by one unit, but the mass of the fuel itself adds to its inertia, slowing it down, but there is also the possibility of jettisoning part of it, or even other parts of a unit to reduce inertia. So, there are many possible answers, but those are some of the domains that are different. [Answer] One answer to the question would be for Capital Ships: Supportive ECCM and CM's and PD in a missile heavy environment. The ECCM (Electronic Counter-Countermeasures) and CM (Counter Missile) and PD (Point Defense) functions could be augmented by more line-abreast kind of formation (or spatially grouped) such the coverage could be allocated between ships as opposed to one ship. Meaning, the ships could offer up a mutual defense system -- so instead of Ship A needing to coordinate trying to dispatch ALL the missiles fired at it, it could coordinate with Ship B to allocate a portion to Ship B who might have a better chance to kill the missiles. Plus, assuming you're down to Point Defense ranges -- the more Point Defense batteries firing the better. For fighters/small ships, maybe not so much...they're better dispersed. Unless it's to hide from missile attacks -- shelter under the big boys and let their anti-missile coverage do the work. Technically, I think assuming it'd be a mix of Aerial and Naval tactics is not so far fetched -- for larger ships, I'd assume the standard 'convention' of weapons could be mounted either forward firing only, rear firing only, or broadside (internally mounted) and thrust elements in the stern -- this being the case, it'd be analogous to naval tactics of the age of sail...I mean, you'd want to Cross the Enemy's T (have your ships able to fire a broadside up the stern of the enemy) or Broadside them. The only Aerial wrinkle to this is you'd be maneuvering in 3 dimensional space vs a wet navies 2D space and need to account for celestial navigation issues and orbital interception vectors. A good 'interpretation' of this might be David Weber's Honorverse, which goes into more detail ... assuming you'll accept that version of cannons, missiles, armor, and shields at relativistic velocities. [Answer] I'd think that with anything near today's technology space battles would revolve around drones and decoys. With the devastating capabilities of our weapons on what would need to be weak hulls I see that as the only real option to limit casualties. I'd also point out that a drone would be far more resistant to G forces than a human pilot. Ecm would have to be compensated for, but any ECM likely to completely shut down your opponents communications will tend to do the same to your forces. In essence the idea would be to interweave the ships containing pilots with drones and decoys similar enough to make targeting the pilots difficult. These drone "armadas" would operate in clusters measured in "tens" of miles to limit control lag. Such a combat structure would be susceptible to nuclear/emp attacks....... but there is little that isn't susceptible to such attacks...... short of burying yourself in an asteroid. Ice shields for the equivalent of carrier/battleship sized craft are an interesting concept, but the idea of compensating drift caused by thermal weapons vaporizing the shielding would be..... "problematic". [Answer] Reading through all the answers it is apparent that the one thing everyone seems to agree on is that it will mostly depend on the current tech. If you were to place the battle in early Space Age, where, say, humanity would colonise its solar system and battle each other for assets in the space system, and assume no huge leaps of tech, then the main components of an effective fleet would be: \*Carriers \*Frigates \*Fighters \*Drones The main focuspiece of any fleet would be its carrier. The carrier would host and deploy its fighters and most drones. The Drones themselves would form a type of 'sphere' around the carrier and they would be mostly tasked with intercepting missiles, and cause havoc to fighters. They would be armed with thin lasers, that pre-detonate any missiles. They wouldn't be as effective against agile fighters, and assuming some armour to them, would not cause that must damage anyway. Frigates would be mostly armed with conventional balistic weapons and have two uses: close quarters brawlers, flinging small bits of metal or shells at enemy ships, that are hard or impposible to intercept, and, at larger distances, would aid the 'missile defence grid' and act as better decoys, trying to draw some fire from the carrier. They would also be the best defence against fighters, given their close range capabilities (think minigun-armed hedgehogs). Frigates would also encircle the carrier, or be arranged in a sort of 'wall', with the side facing the enemy. They would also host their own drones. Fighters, most obviously, would be the main attack force. They would have to be numerous and agile, but small enough so that they are difficult to detect. They would be tasked with reliably getting through the wall of drones and planting missiles in the enemy carrier (or frigates). However, they would mostly be stealth bombers. They could have something to use against drones, such as miniguns, but speed would be their main asset. Fighter dogfights would probably only errupt in deep space, if the squadrons met each other before reaching the enemy fleets. However they would either last too long or too not long at all, given the extreme speed and range. My guess would be that engaging in dogfights near fleets equipped with these armies of drones would be unfeasible for the attacking party, and it would retreat and retry after it out-manevoured its enemy. Smart admirals could potentially make use of large gravitational masses, such as Jupiter, to fling projectiles around, basically making certain areas a 'shooting gallery', and then try to manouver his/her enemy in those galleries. Asteroid fields would be perfect ambush locations, assuming ships can lower their power output and float around the fields like rocks. I'm also guessing that how the fleet is positioned in regards to the sun/star of the system would also affect targeting/spoting/systems. Other space anomalies, such as some glass clouds/nebulas might also create hazards that are either impassible or highly dangerous, but can also be used as hiding spots/ways to lose enemies. Another idea would be to use frigates to do high-speed drive-by's at effective cannon range from the enemy fleet, however trying to drive a wedge through the enemy fleet would probably be a bad idea, since your whole fleet would have limited evasion capabilities, while being subjected to the full firepower of the enemy broadsides. Also, the lack of active drones would leave it vulnerable to nukes. In any case, the way I imagine space fleet battles would work at the momment would be two blobs trying to shoot at each other from large distances, trying to find weak spots in the enemy's drone shield. Flanking would work if the enemy has their drones arranged in a directional cone, in order to better soak up damage from a known fleet. [Answer] Knowing where the Star Wars are going to occur and how to get from where you are to over there would be the first hurdle to overcome when launching Armageddon somewhere in the void. Calculating the location of "your" army in relation to that of your enemy in two dimensions requires two numbers. Length and width, or Longitude and Latitude. With those two numbers you can plot a course and navigate to any point on the surface of whatever rock you happen to be on when the messy work begins. In space, knowing how to plot your location and set a navigation course requires 3 numbers. Height, Width and Length. With those three numbers you can plot any point in space from the tip of your nose to the furthest galaxy. Now that you know how to navigate, your gonna need a ship. Your ship must have a way of crossing the unimaginable distances between the stars, not mention the galaxies. So, what's the most likely way of getting from here to there in time to partake in the great battle that others will only dream about. A "slipspace" generator fills that order quite well. Einsteins theory of General Relativity predicts, among other things, the possible existence of wormholes. Wormholes are tunnels through space. It's the difference between poking two holes in opposite ends of the same piece of paper then connecting those two holes by drawing a straight line and seeing how long it takes the slowest microbe on the planet to traverse the entire distance. Or you could fold the paper in half so that the two holes come so close together they are literally touching. Now how long would your slowest microbe need to traverse the distance? That is essentially how Einsteins wormholes would allow ships to get into the fight very fast, if not instantly. And you wouldn't even have to break natures incredibly slow speed limit (186,000 miles per second) in order to make it to the shindig on time. The speed of light may seem incredibly fast, and using our primitive technology it is, but when you realize just how large the universe is, even the speed of like is snail pace slow. At the speed of light, (300,000 km per second) it would take 100,000 years just to cross the expanse of our own Milky Way Galaxy. As Galaxies go, we are the small frye in a universe so large it is truly beyond comprehension. So, if you can navigate in 3 dimensions and plot a course to the show, and you have the ability to build ships with slipspace generators that are capable of generating enough power to artificially create a hole in space so you can reach "NOWHERE" in time to enter the middle before the lasers and photon torpedo's stop flying. Yeah, fighting in space is possible. But I think the engineering involved with the development of the Shaw - Fujikawa slipspace generator will be so convoluted and difficult, that if we do succeed, fighting amongst ourselves or against evil aliens won't really be a priority. Cause, no matter how warlike you may be, development of the technology to make it all do-able will require that "we all just, get along" & cooperate with one another in ways that are even more unimaginable than the size of the 9 realms, heaven and hell combined. I hope we succeed. Space Battles are only fun when Luke, Spock and The Master Chief team up to take on... [Answer] Accelerating a rock to a high speed is a planet-killing attack. The only defense is to teleport it somewhere else - attacking it with bombs or beams will only marginally change the outcome (unless done long in advance of d-day). As far as ships of the line, it would only make sense if there was defense in numbers which counteracted the capability of the enemy to, say, launch a nuke/emp swarm and kill all of your eggs you put in that basket. What I'm saying is that given any feasible defense, the only real defense is Mutual Assured Destruction. [Answer] Honestly, I think it comes down to the fact that it makes more sense to have the weapons along the port and starport side of the spacecraft recessed into the ship. This would grant protection to the launch bay and the cargo inside while also allowing for the weapon bay to be easily serviced and reloaded. As for the issue of armour on the craft if humans right now went to space to fight a war the armour on the ship would be dismal due to the cost of putting billions of tonnes of metal and other materials to create massive battleships in space but as time progressed and the infrastructure in orbit progressed ship would become capable of very thick armour not to mention undiscovered metal alloys [Answer] This requires 3d thinking and 3d math involved in space warfare. The question which formula will solved this problem? [Answer] There are quite a few assumptions that need to be made to answer the question - largely based on 'assume modern tech'. Space is a relatively new field, and weaponry is currently forbidden by UN treaty - so experience here is non-existent. Currently limited rocketry can only provide small payloads over interplanetary distances, with enormous economic investment. There are no manned ships other than LEO (Low Earth Orbit) and the early Apollo missions that are manned are little more than a few cubic metres of air with almost no fuel, limited instrumentation, with no or very limited ability to manoeuvre. Every action had to be meticulously worked out prior to manufacture and launch - with no 'ad hoc' diversions from pre-arranged mission parameters often worked out years in advance. Battle in such a limited environment is difficult to fathom - but nuclear warheads mounted on interplanetary rockets would be the only currently possible means, however even then often our current exploratory probes into space lose contact, miss their targets, or fail on launch due to the massive amount of fuel required combined with limited technical experience. Such engagement would be very hit and miss, and quite dysfunctional. Let's say however that in your scenario enough technology exists to travel interstellar as in the movie you mention, one needs to take into several key aspects of our current understanding of cosmological science: a) The tyranny of interstellar distance b) The tyranny of time c) Fuel and speed Interstellar distances are so vast, more than most people can comprehend in their minds, and mathematics are the only way to deal with most issues in interstellar space. The movie also sidesteps this issue neatly. In terms of distance even 4 light years to the nearest star system is unfathomable. Sending a ship or missile this far will require tremendous fuel depending on what time scale you would like it to arrive. Say you would like to arrive in 100 years, the fuel you require may be several cubic kilometres for constant acceleration depending on mass, with speeds nearing relativistic limits. Even then, accuracy must be unbelievably precise, and there is such a high chance of failure you may not even know if the mission is successful or not. If however you were ok with 10,000 years, then you could get a ship there with limited fuel and mass, however would there still be a 'war' on or would your civilisation actually even still exist to defend? Such a 'battle' would simply not even be worth the effort of conducting it when you consider the timescales or distance involved. Many movies still base their stories on old WWII strategies and tactics. Such thinking is unrealistic when dealing with the tyrannies of interstellar distance and time. Thinking 3-dimensionally is the least important issue to consider. [Answer] Two considerations: A: If I have a friend next to me, his point defence can help me with my point defence. It means that the enemy has to concentrate a lot of firepower on one point to overwhelm my defense. That means he too will stay grouped to minimize delays in syncronizing attacks. I suspect that you can get a first model of this using swarm simulation models. B: It's not three dimensional but six. This doesn't come out in the Enderverse much, but it really comes out in Weber's Honorverse In addition to 3 spacial dimensions you have 3 velocity (or momentum) dimensions. If you and your enemy pass each other at .3 c targeting starts to become, 'interesting'. In days of sail, your velocity was dependent solely on the wind. In times of steam, on your power to mass ratio. In space the dependents are acceleration. velocity depends of acceleration and time. Consider you are breezing along a 1000 km/s You have the capability of doing 10 g. It takes 100 seconds to change your velocity by 1 km/s It takes over a full day to either stop or to double your speed. At any given time you possible future locations are exponential horn in front of your current velocity. Cutting across that are pairs of surfaces representing the limits of where you can be at some future time given your present acceleration capability, and present velocity. Now, that day's travel at 10 G. That's 5 \* 10^8 km Something like half a light hour. If you're using radar, your information about where the enemy is is almost an hour out of date. Fleet tactical officer is a daunting job. And while you can't hide in space. you can easily make things that look like you. Ever notice how bright road reflectors are. So you have a bunch of very light drones in front of you with corner reflectors that are sized to have the same radar reflection you do. If you are a capital ship you may have bucket fulls of drones. If I can use a 1 million dollar drone to lure your 20 million buck missle into turning it into confetti, I come out ahead. Maybe you can hide. Suppose you use surplus energy to make ice. You start into a battle with all your reserve water as a few swimming pools of ice shards. Turn off your engines. Go dark. Reactor is on standby. Life support is running. All unnecessary power is shut down. You coast. You listen hard with your radar ears. Passive radiators on the back side of the ship glow red, to stretch out the ice. If your ship is painted black, and has an radar absorbing coating, you are going to be harder to see than Nelson's HMS Victory on a foggy day off Ushant. If you can absorb a couple day's waste heat you can be a very nasty surprise. Weapons include chaf. Send out a small nuclear bomb. Around it is wrapped a ton of carbon. Wrapped around the bomb is super conducting coil of wire with a big magnetic field Blow up the bomb. The bomb explodes. It destroys the coil and forces the magnetic field to be much larger. The field is trapped in the plasma. the plasma pins the field. You now have a ball of radar absorbing plasma several miles across. move a conductor across that field. voltage is generated. burn out non-hardened circuits. Carbon can lose 6 electrons. So in addition to neutral carbon (not much) you have a soup of electrons and 1 to 6 times ionize carbon. As long as that carbon is ionized, it's trapped in the plasma. Oh it disipates after a while from collisions. Bet it takes days. [Answer] I suggest having a look at a video of some fights in EVE Online. People tend to cluster together to benefit from shielding, while they surround themselves with cannon fodder in the form of small ships and drones. There are small 'elite' packs that fly alone and focus key targets like long range ships or Titans. Overall, it really depends on what kind of technology is available in the setting at hand. ]

[Question] [ A group of people have stumbled into one of those classic fantasy/horror houses where the usual rules of space don't seem to apply and is very confusing. Bits of the building appear to overlap with each over. Eg. from the front room you walk forwards ten paces and enter the kitchen. Turn left 90 degrees and walk forward another ten paces. Turn left another 90 degrees, walk forward ten paces into the dining room. Finally turn left 90 degrees and walk another 10 paces forward and you end up in the study, not where you started. You can back track and get back to the front room. The rooms don't move about, there is no way to detect the bits that overlap. The house is very large. Due to the way the rooms overlap there is more volume inside the building than contained by the exterior walls. All the rooms appear to be on the same plane. There is no climbing through holes in the ceiling, or rooms with right hand wall being the ceiling, from the point of view of the door. Having checked out the house for monsters and finding none they decide to try and make a map to stop them selves getting lost in future. Of course simply drawing rooms on paper becomes a problem. They started to carefully fold and cut layers of paper so where the building overlaps you can fold sheets out of the way to find the layer you are on. Each time they find a new room they end up having to start from scratch to figure out how to get the map to fold correctly to incorporate the new room. However this has created a very unwieldy map that is very hard to use. Is there a better way to create a map of an area that "overlaps" its self? [Answer] Create a topological map where it is only the relationship between the rooms and corridors that is significant, not their physical position relative to each other. So in other words if you imagine a triangle with a room at each corner, going from A -> B -> C and then continuing would normally get you back to A. However a topological map might show A, B, C and D on a line so you know that going from C will lead to D rather than back to A. If journey distance is important then you can write the distance next to each line ("corridor") to show the distance between each room. Think of something like the London Underground Map - This does not attempt to show the physical relationships between stations (other than broadly speaking), only the "lines" that go between each station showing which routes you can use to go from Start to Finish by visiting or changing trains at points in between. [Answer] I would map this in a more abstract way, essentially you are just looking for a graph of what connects to what. Draw each room as a rectangle (or whatever shape it is) on the paper and map the contents as usual. For the connections between each room just draw a line connecting the doorway of one room to the corresponding doorway on another room. The result would be like a flow chart of possible routes through the house. [Answer] If you need a map thats actually "easy" to read and to use you need strings, duct tape and paper. Each piece of paper represents a room and every piece of string represents a door to another room. When you need to get from room A to B you stack all papers, flip until you reach the first room and pinch that paper. Now you flip until you reach the other room and pinch that too. Now you shake the map and look for the path with the least connections, always changing grabbing the next piece of paper as you change rooms. If you have a computer at hand or a bigger table you could enumerate each room and label each door and use an algorithm to create a list of shortest paths from any given room to another following the door-labels. As a third solution, to find your way around without a map afterwards you can take the Kreta labyrinth aproach and use paint or strings to lay a path from the very first room to points of interest. You can color code those and maybe attach directions markers so you know which way to go. [Answer] This is very similar to other suggested answers but instead of clogging your map up with lines you can use symbols to identify connections. Draw each room on a map as a square with indications where one room leads to another. On this indicator draw a symbol such as 'A', '1', or '@'. Then on the corresponding indicator on the second room draw the same symbol. You see something like this on many maps to indicate which staircase from floor 1 ends up on which staircase on floor 2. All we are doing is changing it from indicating staircases to indicating room connections. The benefit to this would be that is may be easier to read at certain junctions. If the imaginary house has multiple cloisters with 8+ exits out of it, the lines get tangled up very quickly. The downside is that it requires more room on the map and it can be difficult to find matching symbols if there are hundreds of rooms or messy handwriting. Another option would be to label each room with a symbol, and each indicator with the symbol of the room it leads to. This may let you identify routes more quickly, 'I want to go to D, which rooms have a D on an indicator' instead of 'I want to go to the kitchen, which routes have a D or # or $ or 0 on an indicator' but it doesn't allow you to know which door in the target room you will come out of which can be an issue if the doors in the target room aren't all connected. Such as a broken catwalk connecting the doors to each other. You could even create common pathways on a 'key' by simply writing out the path such as 'A@b178IU' to get from the entrance to the bathroom in 7 easy steps which is something you can't do with lines connecting each room. [Answer] For the room layout you described, it's easy to draw in [hyperbolic geometry](https://en.wikipedia.org/wiki/Hyperbolic_geometry): [](https://i.stack.imgur.com/BTrRc.gif) [The Mathematics of Old School D&D](https://mathofoldschooldandd.blogspot.com/2012/03/dungeons-and-geometry.html) explains that concept well (the above image is theirs, and it's exactly the five rooms you described in the beginning of your example). Slightly different kinds of oddities can be drawn by following the rules of other non-Euclidean geometries. [Answer] If you have some time, you could build a simulation of the house (with a computer). Real-world rules (such as the idea that buildings should be smaller on the inside) don't have to apply in a simulation. [Answer] I'm going to shout in on the layered map approach. The adjacency graph already being covered. Only do nothing like this if you need local detail. Draw the map on pieces of post-it notes. They can be easily peeled off. They are also transparent, so you can see under them when you press them down. Use this to mark the positions. The alternative is to draw it as an isometric image with shifted layers. [Answer] Draw the map in different colours, and view the "layers" of the house through differently coloured lenses to block out the other rooms. The lenses could be salvaged from a 3D movie, or something like sheets of cellophane laid over the map. For an example - the back of the Declaration of Independence in *National Treasure*. Separate layers of information existing on the same piece of paper. ]

[Question] [ An intelligent race evolves on a planet with no moon or axial tilt, which is tidally locked to its star, and has a very hazy atmosphere. So there are no seasons, no day/night cycle, and the stars are not visible either. The planet has a permanently dark and a permanently bright side, which will probably cause some nasty weather, but the important thing is: there is no natual phenomenon which would force the concept of time on its inhabitants, no periodic events which are always the same and affect everyone's life. How will they organize their lives? How do they cooperate on tasks when there is no such thing as "tomorrow" or "at dawn"? How will a lack of seasonal agriculture or animal migration affect society? Even more fundamental: can human-level intelligence even develop when there is no real need for planning ahead more than a meal or two? How different will their thinking processes be? [Answer] ### They could likely develop both time and technology, but likely very slowly If we postulate that there would be essentially no variations in the nature around them - constant light, constant food supply, constant season - then timekeeping will be difficult, but not impossible. **Discovering time** Unless everyone is immortal, then one thing they would notice to be cyclic would be lives. They would eventually realize that everyone grow old and dies, which would give a base for starting to track time. This would still make it tricky as the time which is required for a life is quite long and it varies a lot from individual to individual, but they should still notice that something passes as they get old. A shorter measurement would be hair growth ("*do you remember when we went on that trip, it was when your beard was only a hand long*"), but that would be affected by their biology (maybe they don't have hair) and their cultural setting (maybe long hair is taboo). If nothing else, then they would still eventually notice that seeds planted eventually will grow; even if there are no vegetable cycles, they ought still have noticed that a tree which once were only the height of one man now stands five man tall. Another thing they can learn about the passage of time indirectly would be from child's play. If they are playing with sand or water and pouring it from bucket to bucket, then they would eventually notice that it takes a bit of waiting for the pouring to complete. This would allow some smart individual to standardize that a sand pouring from a certain sized bucket to another would take a reasonable long waiting time. Lets call this reasonable waiting time "*an hour*". And by keeping track of how many pourings of "*an hour*" that one needs to wait, it would be noticeable that e.g., the hunting party usually takes five pourings of "*an hour*" before they come back home, but sometimes less and sometimes more depending on how easy the hunt was. But would they ever develop any further use for this? That's hard to say - someone ought to be interested in measuring stuff, but it will take quite many pourings of "*an hour*" before the beard gets noticeable longer or before the tree grows to twice the size. And by the time one have poured enough hours for an entire life, then one have likely lost count several times over. **Conclusion on time**: they would, at least indirectly, notice that there is a passage of something. Whether they will understand the concept of time from it and whether they will use it for something will highly depend on the wise elders of their society. It is not unlikely that they never will understand time, but it is highly possible for them to do so. **Developing an advanced civilization** As for the development of an advanced civilization - if they live in quite tropical climate with no dangers of lethal weather, no dangers of long periods of food shortage or anything else in nature which would force them to plan ahead, then why would they? If one compare how advanced different civilizations have gotten, then there is a very strong correlation to how lethal the environment is. As example: the further up north people have lived, the more important it has been to collect food for the winter. If there always will be fruits on tress and animals to hunt, then why bother collecting for half a year in advanced? This does not, however, mean that they cannot develop any advanced civilization. Both Mayans and Egyptians developed quite advanced civilizations without a real need to gather food for the winter. Nonetheless, is an undeniable fact that the more one is forced to plan ahead by nature, the more inclined individuals will be to figure out smart solution to make it in time for the nasty period and to survive it with little to no means. Part of the development towards a more advanced civilization would likely be if they decide to start growing crops instead of being satisfied with a hunter/gathering society. By settling down, they would have more time to tinker and a higher need to develop solutions - one can plough a whole field manually with a shovel, but if one is smart enough then one will realize that it's less of an effort to do so if one creates a large shovel and strap it to an ox. One can drag heavy building materials entirely by hand, but it is far more convenient to use wheels (something which, interestingly enough, Mayans failed to invent despite an fairly advanced civilization). **Conclusion on development**: It is likely that they would become quite lazy and not really develop any advanced technology unless nature forces them to, but there is nothing which prevents them in doing so if someone find it amusing to tinker with inventions. They would likely eventually reach a decent tech level, especially if they settle into small towns, but without a harsh whip from nature, it would likely take much, much more pourings of "*an hour*" before they would do so. ### So, to assessing your questions * **Can human-level intelligence even develop when there is no real need for planning ahead more than a meal or two?**. Yes, high intelligence can develop despite no need to plan ahead. Humans only needed to plan ahead for a meal or two when the majority of our intelligence developed, but still we got really smart. There are several theories on how and why our [intelligence developed](https://en.wikipedia.org/wiki/Evolution_of_human_intelligence), but it is believed that one of the major driving forces is the development of our language which we benefited from when hunting. Other animals also show remarkably high intelligence without the need to plan ahead at all. Take [crows](https://en.wikipedia.org/wiki/Corvidae#Intelligence) as example, they are capable of both [using tools](https://www.youtube.com/watch?v=DDmCxUncIyc) and advanced [problem solving](https://www.youtube.com/watch?v=ZerUbHmuY04), and they might have a rudimentary language. * **How different will their thinking processes be?** This is impossible to say for certain without knowing more about their culture. If you mean compared to humans in general, then it can be either the same or completely different depending on what you as author want it to be. Cultural differences can cause completely different ways of reasoning - just look at how various cultures among humans might reason. If you want a baseline for how they might think, then I would point towards tropical cultures on earth - however, I am not skilled enough to give an fair overview on how they might differ from, e.g., an Eskimo's way of reasoning. * **How will they organize their lives? How do they cooperate on tasks when there is no such thing as "tomorrow" or "at dawn"?** Again, it depends on how you want to create their society. You can gather a lot of references from how housing and organization looks in warmer climates. My guess is that most of them would take the "day" as it comes, it will be hard to say when will be active at which point if they have no day cycle to organize sleep from (will they even have sleep?). Likely they will do stuff when the need arises. If they need to build a new house, then they will build a bit when everyone interested in it's completion have energy to do so. If they need to harvest grains, then they will probably do so when the grains are done. * **How will a lack of seasonal agriculture or animal migration affect society?** I point again to warmer climates. I saw a documentary about the life in an African country (can't remember which), where they had a fairly decent amount of crops around naturally. They spent their days with going out hunting if they felt like eating meat, they gathered grains fairly often as it was a base food, they built a new house for a newly formed family which took a couple of days. Whenever they didn't need to gather food or do something immediate, they largely spent their time socializing and strengthening their relationships. [Answer] They are intelligent, therefore they can notice that they grow up. Growing up is change, and change can only occur in a dimension called time. You might ignore the concept of "meter" or "yard", but you can still understand that if two positions are different, they differ on something called "distance". By analogy they can start to think about a temporal dimension they need to be able to quantify. The lack of periodic astronomic events will only affect their choice on the number, not on the concept of time. Before standardization each city had its own "metric system", the same could happen on this planet, with each city having its own "temporal system". [Answer] > > How will they organize their lives? How do they cooperate on tasks when there is no such thing as "tomorrow" or "at dawn"? > > > If the aliens need to periodically eat and drink, they could measure the time by getting thirsty/hungry. "Two big meals ago" or "before I get hungry again" are very approximate concepts, but might be enough for some cooperation. And, of course, they might have a pack leader who just says "me hungry, all go hunting". If not - for example, the aliens just constantly photosynthesize, and the weather and predator attacks are unpredictable - they will simply cooperate when in trouble. > > How will a lack of seasonal agriculture or animal migration affect society? > > > Far less than "being an alien culture". I mean, our current society is not that affected by seasonal agriculture or animal migration, too. > > How different will their thinking processes be? > > > Can vary from "total aliens with no concept comprehensible by human mind" to "they think just like the [Amondawa tribe](http://www.telegraph.co.uk/news/science/science-news/8526287/Amazonian-tribe-has-no-calendar-and-no-concept-of-time.html)". [Answer] Are you sure there isn't none? Animals and plants have specific cycles that are somewhat sync'ed together. Those cycles are important for those creatures - they control growth, pheromone release, estrus, and several other things. We're not even dealing with the need to sleep here - it's just the normal, less perceptible stuff. A child takes some months to be born. Girls have their first red week a few years in life, around the same age. Children learn to walk and talk at certain points in life that are more or less the same, with some variation. People eventually die. People poop. You can try to take away most of the differences in climate and whatever, but in the end you're still limited by the speed of the chemical reactions that make stuff happen. Those reactions aren't random - life is just a overly complex engine to process food and make more of itself. And, as every engine ever, every step happen is a predefined chain that ends up repeating itself again, and again, and again until you don't have anymore fuel. Even the sun works somewhat like that - the fusion cycle will going while it has fuel for it. In your case, you climate will be your large-scale clock. While you may try to take away seasons and other stuff by removing the axial tilt, you still large-scale wind-streams, clouds, rain, and a lot of other stuff. The climate will change according to the distance from the sun that - unless you go with a perfectly orbit - will create some sort of seasons on your planet. If you really want to go with "plants are random and there is no sync between them" (good luck explaining how flowering works on that case), a village just need a single tree to be able to track time. When it flowers? When it gives fruit? How long does it take for a fruit to grow ripe? You can't go with "random" for those. --- ***That Said,*** The simplest non-sun based clock I can think of is the [water clock](https://en.wikipedia.org/wiki/Water_clock), which, really - your people won't take long to figure out how it works. It's that simple. [Answer] Assuming that they sleep, they would at some point probably find it useful to synchronize their sleep cycles so that they would could work on projects that are best accomplished with multiple helpers. Anything from hunting to lifting heavy objects. From there, I could see that it might be useful to have basically two sets of sleep cycles: an A Team and a B Team, so work could be attempted/accomplished at any time. That would define a "day": a complete wake/sleep cycle for both A and B. Even before then, a complete (average) sleep cycle would define a unit of time. Other activities could also define units of time. How long to walk as far as you can see? That might be called a Long Walk. How long can you hold your breath underwater? How long does it take you to eat? How long does it take for meat over a fire to cook? How long before milk spoils and is dangerous to drink? How long does it take for wet clothes to dry? I don't think it would be that abstract. [Answer] Even at the dawn of civilization, there is always something that can show that time passes. Sometimes long, like the time it takes for a new baby to grow into an adult, or for an insect-like or snake-like creature to molt; sometimes short (in the grand scheme of things), like a long walk between caves, or "I just ate and am not hungry" to "I'm hungry now"; and sometimes very short, like the time it takes for a wave to hit the beach and retreat, or the time it takes for a pebble to fall to the ground, or simply saying a word or phrase (one hippo-analogue, two hippo-analogue...). That can give very coarse time values, or very short time values; you wouldn't be able to cook a roast by pebble-falls (start the roast, drop a pebble five thousand times, check if it's done), nor would you be able to use lifetimes. A long walk (five times around the cave system) may work, however. As time goes on and technology improves beyond the stone-age, people will see that sand or water takes some time to fall, and can make hour-glasses or water-clocks. Candles take time to burn, so a well-marked candle could easily (and fairly regularly) show the progression of hours. Even a lamp burning fat could have markings on the side to denote time: fill the lamp and light it, put the roast in once the fat has melted, take the roast out when the fat level drops four lines. Once time can be marked, inventions measuring (and using) time will spring up quickly. Knowing that Junior takes half a candle to walk to his friend's hut to borrow a cup of sugar, Mom won't believe junior when he makes an excuse for taking a full two candles to go and return. And farmers can plant on a schedule, once every full water-clock-cycle, to make sure food ripens evenly, and not all at once. Once time can be measured at all - and this will happen early on - your people will soon find ways of measuring time more and more accurately, and will eventually think digital watches are a pretty neat idea. [Answer] > > there is no natural phenomenon which would force the concept of time on its inhabitants, no periodic events which are always the same and affect everyone's life > > > So you say they have some kind of plant. So the plant have vegetation stages. BAM! Periodic event. You say they have tasks. BAM! Fulfilling a task take... time. Lack of season agriculture is nothing hard. Look at tropical regions. For example on Cuba you don't have "winter/summer". You have "hurricane season". You didn't explained why you think there would be no need to planning ahead. [Answer] I first consider units of measure. Any highly-intelligent beings will be at least somewhat interested in measuring things that change over time. This would require some established unit of measurement if any mathematical precision is to be achieved. Without their own moon or any visible heavenly bodies, intelligent cultures would find other ways of establishing units of time. For example, they could come up with a "podt", the time it takes for a pebble to drop to the ground from roughly a "zodt" high, and using their numbering system (possibly base 7 because they have 4 fingers on one hand and 3 on the other, or they are smart enough to pay that much respect to prime numbers), they could extend that to larger collections of "podit" (plural) much as we do with our metric system. Perhaps the lack of significant natural time-telling mechanisms, such a culture would develop with a different take on the meaning of time and how it influences the world around them. In the case of humans, we see time as happening on a line, but that isn't necessarily the case. Perhaps their unique perspective would give them an unexpected advantage when it comes to understanding time. [Answer] If these people were sensitive to these things, they might be able to detect the incidence of cosmic rays. Although the rate of collisions would vary with activity of their local star or stars, these would be a way to measure time between each collision between a gamma photon and their sensory apparatus. A Geiger counter, for example, reports radioactivity as an audible ‘click’ each time a charged particle or gamma photon ionizes the gas inside a tube, causing a small difference in voltage within the tube: <https://en.wikipedia.org/wiki/Geiger_counter> Possibly their bodies are synchronized to the rate of these radioactive events much like an ectotherm with the ambient temperature: more cosmic rays speeds their metabolism. Don't forget the nuclear decay of abundant radio-isotopes, also. So, although you stipulate that there are “no natural [phenomena] which would force the concept of time on its inhabitants,” I recommend that you thoroughly reconsider the nature of that world in which they would live — both from their perspective and from a theoretical one. [Answer] # Even in such environment plenty of evidence of the passage of time will exist I imagine that a earth like planet orbiting tidally locked to a red dwarf star will have stable and strong winds and rivers. Since the pressure systems will remain constant I expect the atmosphere and oceans to have very stable flows like the oceanic currents that we have on earth, maybe way stronger. With stable pressure systems, topografy will generate turbulence, some weather patterns will be cyclic. In some places the wind changes may happen periodically. Stare to a turbulent river for a few hours and you will understand what I mean. With stable winds, dead trees may wave like a pendulum and may be the basis of a local time measurements. Not very easy to avoid cyclic patterns on nature. # But let suppose we can make an environment free of the clues about time I understood you question to be about the human learning. Not about the exact environment. For the sake of the argument, let say we could produce such a stable environment and that does not make the planet uninhabitable. Even without any clues of the environment, people will develop history based on the life interactions. That will give the understanding of sequences of events which is what I understand as time. [Answer] Time will be measured by wave travel over distance. As they notice the time delay between the source of a sound emitted and its arrival at a distance away, they will use this as a way to measure both time and distance, depending on which one is known. When they know the distance between points, they can set up their pendulum clocks to a set interval to meet the time it takes for a standardized very loud noise to reach a certain distance away. A set of high quality pendulum clocks can be calibrated to the one standardized location set up for this purpose to eliminate sound barrier interferences that could occur at other locations, and other clocks would then be calibrated to these. A periodic recalibration would be set up using whatever calendar they develop based on other natural rhythms they notice (as other answers indicate, there are many). Regarding your question specifically as to whether humqn intelligence will advance, it is within human genetics to become more intelligently advanced through learning and adapting to an environment, no matter what that environment is. To learn is intrinisic nature of humans, therefore although the rate of intelligence growth will change based on the environment, any variety at all in the environment will activate learning and increased intelligence. ]

[Question] [ A not widely accepted psycho-social phenomenon but one our descendents might sometime face, [the Three Generation Rule](http://www.projectrho.com/public_html/rocket/spacestations.php#id--Station_Station_Problems--Three_Generation_Rule) states: > > that the degree of social discipline needed for a space habitat to > survive indefinitely is beyond the capability of "normal" human > societies. The human tendency to favor short-term expediency will, > over time, make the habitat ecosystem more and more precarious. > > > Putting it loosely, people tend to put off patching the leak in the > roof till its raining. > > > In the Ten Worlds setting, this means that space habs tend to run > down, and fail catastrophically in 1-5 generations from when they were > established. The average is 3 generations, hence 3-gen rule. > > > It works somewhat like the [three generation in wealth building](http://globaleconomicanalysis.blogspot.com/2009/02/wealth-does-not-pass-three-generations.html). 1. The first generation scrounges, saves, and manages to put 10% of their wealth aside for investments over a 45 year period. 2. The second generation is instilled with some of the discipline to maintain the wealth but *perhaps too optimistically* relies on the knowledge that they'll get inheritance from the first generation. 3. The third generation hasn't seen the effort required to ensure a safe and comfortable retirement. It usually & mostly fails to save money in any meaningful way or wisely invest any money they may have inherited from prior generations. Often they spend any capital they've acquired trying to keep up with their wealthier friends. They end up frittering away the wealth. Only in a society entirely maintained artificially, failure to manage your colony responsibly and with discipline means certain death for everyone on-board. In such a society the people need to thread carefully between the wide-eyed green idealism and the greedy corporate capitalists. Either side could be good or bad depending upon the issue at hand. Allow anyone to run-away with their ideals and you could doom an entire colony to death. In societies with very large populations, some people in each generation are moving up and taking on a more technologically sophisticated (and/or disciplined) jobs than their parents to take the place of others are moving down. But in small populations, a slight imbalance in one of the generations leads to the catastrophic failure of the colony. * How do we develop a society that can survive in an artificial environment, that requires at least a small group of people in each generation to dedicate themselves to topics they may have no interest in pursuing ("But dad, I don't want to be an algae sludge farmer!" "Sorry daughter, you scored highest in the aptitude tests."). * Also how do we ensure that essential skills aren't lost due to the death of people with extremely specialized skill sets? **Edit & addendum:** *7/13/2015* I don't like answers with automation in them. The reason is automation tends to replace human labor in unskilled or repetitive jobs. It replaces them with machinery that requires technical and/or specialized skill sets to maintain. I think that ultimately a colony is most likely to survive in a situation in which **no** technological skills are required to maintain it - meaning the environment is passively maintained by the environment. This means an environment that naturally supports life and this typically means a planetary surface. If we can't have such a thing, how do we ensure that the society can survive for 10 or more generations (e.g. for a generation ship to travel to another world)? [Answer] Ok. Here's my answer. The "ship" needs to be big, so big that it's capable of providing a self-sustaining, self-regulating environment like the Earth's biosphere does. No air filters to change; instead, forests of trees will provide oxygen. No algae sludge farms; regular farms will do nicely. People have been growing their own food for thousands of years, and they can do it for thousands more here. A hollowed-out asteroid, spun up to an appropriate speed to provide gravity, would be suitable. The cylindrical interior of this "ship" is like a small, inside-out planet where people can live and breathe easily, as they would in their natural environment back home. The larger the asteroid, the more robust the environment, and the more room for a larger human population which will maintain better genetic fidelity over time. A space 2 km in diameter and 2 km long provides 12.5 km$^2$ of livable surface area and 6.28 km$^3$ of breathable air, sufficient for 10,000 people at a population density of 1.25 hectares per person. Some kind of "sunlight" will be required: I suggest a nuclear energy source, designed to last for millennia without maintenance. Why give people the chance to muck up such a vital component? No need. Nuclear fission (or fusion) can burn for a loooong time. This makes maintaining a stable living environment easier, but it doesn't solve everything. You still need people to: 1. Remember their technology. What's the point of travelling to a distant world if, by the time you get there, your people have regressed to the stone age? They won't even be able to get off the ship. Language retention will also be important, so they can read the ancient texts and follow the recorded instructions for landing once they finally get there. 2. Take care of their environment. If you think this is important on Earth, it's ten times as important in a relatively small, enclosed space capsule like this. Pollution, deforestation, overpopulation, and extinction (not to mention war) need to be absolutely avoided. Religiously, in fact. Religion, or something like it, *is* the key to making sure this happens. The mythology of this religion is simple, and it's extra compelling because it's completely true: this world we inhabit is actually a vast ark, sent off long ago to travel through the universe to another, vaster, distant alien world. Some day, we'll get there... and when that happens, we need to be ready. As you can see, it's got something in common with some of the more popular Earth religions, stories which have stood the test of time. There's the "chosen people" narrative (always a winner) which in this case includes everybody on board - but, our spacefaring acolytes still have the mythical schlubs back on Earth to feel superior to, so it's not all bad. Then there's that "day of reckoning", "end times", "world beyond our world" angle... we *know* humans dig this kind of thing. But in case this isn't enough to make it stick, we can borrow an even more powerful trick from an even older period of human history. Nearly all ancient tribes used rites of passage to cement a young person's relationship to the ethos and mythos of the group. This form of ritual has been so pervasive because it's so effective, and of course it's still around today. The Marines use it. Fraternities use it. Cults use it. The idea is to use drugs, fasting, or some other means to induce an altered state of consciousness, break down psychological barriers, and induce a state of "imprint vulnerability", wherein the subject's mindframe is susceptible to permanent, groundbreaking change. Fraternities use peer pressure, humiliation, and beer for this purpose; cults may use faith healing demonstrations, group hysteria, or psychedelics; the Marines use intense physical training, camaraderie, and the horrors of war. All good, but we've got something even better. Let me tell you a story to illustrate. A girl is born in a village near one end of the "ship". As a child she's exposed to the standard mythology and tenets of her world's religion, and accepts it unquestioningly, as children do. We are a chosen people, approaching a great destiny; we must shepherd our world, keep all things in balance, maintain peace with our neighbors, and learn the ancient language and knowledge so that one day, when our time of reckoning comes, we'll be ready. All this she takes for granted. Eventually, though, she starts to grow up and to question her place in the scheme of things, and wonder whether any of it really makes sense. This is fine; it suggests that she's maturing intellectually and is ready to begin learning the deep magic of the ancients (electricity, metallurgy, semiconductors, photolithography and so forth). However, there's really no room for deviation from the principles in this society, so the point needs to be brought home in a big way that this is *real*, and an imprint created of this epic, magical sense of manifest destiny that will last for the rest of her life. So, as happens to all children on the eve of their adulthood, she's sent to the far end of the world (a pretty short walk, in this case) where there is the entrance to a cave. All kinds of symbolic rituals could take place here. She could strip naked and be covered in paint; the cave could be on a sacred island on the far side of a swamp where she'll be rowed across at night by masked, chanting monks. It doesn't matter: this part can evolve organically, as rituals will do. What's important is what's *inside* the cave. Also, preferably, that she not have the slightest idea what's in there before she enters. The bigger the mystery, the bigger the fear, the bigger the impact. It's dark inside, to start with. Soon after leaving the entrance behind, it's *completely* dark. The floor is smooth, though, and there's only one way to go. Feeling her way along, she hikes up a steep incline, initially out of breath; but after some time, she begins to notice something different. Incredible as it seems, she's growing lighter. Each step seems easier than the last, until she's basically swimming through the air, unfettered by gravity. At this point, a slight glow begins to fill the cave again. It's not much, but her eyes are by now highly attuned to the darkness, and the faintest glimmer of light is visible. This makes the next part even more mind-blowing, as she comes around a final corner, into a vast, transparent half-dome at the very nose of the ship, and sees - for the first time - the stars. Bam. She's *never* gonna forget that. *Ever*. When she gets back, and her training begins, there's even more in store for her: science, the knowledge of the ancients, will start to reveal its mysteries, explaining everything she just saw and more. It might seem that this is giving away the magic, but any scientist will tell you that a greater understanding of nature doesn't in any way cheapen the thrill; totally the opposite, in fact. That's important, because these people are going to need everything they've ever learned, and furthermore they'll need the ability to discover, adapt and invent. This can't become one of those dead religions, where people accept what they're taught and follow it blindly until they die. People need to not just understand technology, but be capable of creating it for themselves. That their survival is basically pretty easy, with not a lot of work required to maintain it, definitely helps. There should be plenty of time for learning and intellectual pursuits. Strong critical thinking skills, widespread education, a generally prosperous and easy lifestyle, a decentralized, democratic society, and a powerful sense of common purpose *should* be enough to keep this community peaceful, intelligent, and healthy - at least until they arrive. At that point - anything could happen. :) [Answer] There are several possible ways to do this. You would want to maintain a stable society where certain things are done "automatically". A theocratic society such as the ancient Egyptian might be a model, where daily life revolves around rituals and beliefs. Instead of worshiping the world of the dead, you might be imbued throughout your life from childhood to worship the Sun as the source of all energy and the provider of power to the ecosystem. Solar priests are high on the social ladder (just below the Pharonic "Mission Commander" Himself) and their word is law. Of course, it is not all drudgery. After the ritual of the mirror cleaning and the allegory of the mutated algae is played out, there is the festival of recycling and the ever popular reseeding of the living quarters. The ship or colony can also be divided into the "Crew" and the "Passengers". The Crew is a military like organization who are trained in the various disciplines of keeping rings running, and are NOT self perpetuating; recruiters look at every generation to select the best candidates from children of both the Passengers and Crew; being born into a Crew family does not automatically ensure you have what it takes to be a Crewman. So long as the idea of a meritocracy and open selection survive, the Crew will be able to keep things running. In order to prevent a sort of inbred Passenger/Crew thing from happening (the Passengers become slothful and don't care to become Crew) there should be enough perquisites ("perks") to being Crew that entering Selection becomes desirable, and Selection itself should be challenging and fun. Maybe children are given access to social media games of increasing complexity that give them a glimpse of Selection and crew life. The lesson of the United States is to create an society which encourages and rewards social mobility. It may not matter if *your* family has gone down the "three generation path" so long as other families are moving up to take their place. And of course, you can restart the cycle for your family, becoming the new "first" generation rather than remaining a slacker "third". So long as the dynamic is rewarded, rather than punished through laws, regulation and taxes, then people will continue to follow incentives to succeed. (The other lesson is there can be no welfare state in Space). [Answer] **Use advanced AI and Automation for the "Boring" stuff** Have an advanced AI and a team of robot menials doing the boring stuff. One of the big movements in the workplace at the moment is towards automation. There's no reason why the really boring basic stuff can't be done by robots. The only exception to this is management - its harder to teach a robot what to do when it all goes wrong, so the majority of what humans will be doing in a colony will be creative and reactive, not menial. Therefore, any colony will likely have very few people confined to menial survival critical tasks - it'd be more creative and reactionary tasks "Oh bugger, algaefarmer065 has a dodgy motivator. Looks like I'll have to cobble together a fix for the damn thing a-*gain* or its ration bars for dinner tonight". I'm aware this still could be boring, but it also allows the colonists some measurement of control and not being a cog. It also allows you to train your colonists to approach things laterally which means they can improve things for themselves. Automation is also often a progressive thing. If you have teachable AI, you could teach a robot to be a maintenance person and free up some of your time. If you're not being paid by the hour and just surviving, the more time you can devote to automation in the short term, the more time you get back in the long run. **Improving Quality of Life** There is something additional to be had here too - conservation of materials. Assuming your setting hasn't got mass-replication or portal networks, any components etc are going to have to be flown in. I would therefore anticipate any human enterprise to be more around making things work with the bare minimum. After all, if you can patch something with local materials, you can then use the stuff that's been sent out as replacement or repair to improve your current lot. One example is fixing a solar panel rather than scrapping it, and using the replacement one to improve power output so you have a warmer habitat. **Keep 'em Busy!** A final one is to keep your colonists busy and have them directly see the benefits of what they're doing. Using the example of Algae farming, you'd not want someone doing this - you'd want this to be automated. If it was someone literally standing over sludge all day pressing buttons, that's a recipe for an unhappy worker - one who's more likely to goof off and cause issues. If instead they're reactively responding to serious issues, whilst also spending "downtime" improving things for themselves and their neighbours, they'll be much happier as they'll see that they are important and making a difference. This last point would feed heavily into some of the social stuff already mentioned - if your neighbour hasn't been pulling his weight, he gets pushed down the priority list for fixing non-critical things, or he finds his power allowance drops first, or his "nice" ration allowance shrinks first - or he pulls the nasty jobs ahead of others. [Answer] **Almost ANY and ALL societal models can (and will) survive.** A highly artificial environment will, by nature, be highly automated. It is not likely humans living in such environments would need to be particularly proficient engineers. Not nearly as much expertise is needed to maintain a machine than craft the machine. Also, you only really need ONE person to seriously 'know' how the system works, the others can simply borrow from their knowledge. Even if this person dies, the next most knowledgeable person likely knows far more than is needed to keep the ship in working order. Provided you can maintain an decent archive and library of knowledge, I'd contend the 'three generation rule' simply would not apply to to a space colony. Our society today tends to overstate the importance of its own education systems, as such it can be hard to escape the impressions they create, such as some rather odd and arbitrary distinctions between 'professional', 'volunteer', and 'hobbyist'. Our colonists would have as much use for a 'professional' algae farmer as they would for a 'professional' shoe lacer. There is nothing particularly difficult about electrical, mechanical, structural, or other sorts of engineering. Actual, practical experience offers a far more valuable education than can be accrued in the modern classroom setting, and your colonists can no more 'escape' the mechanical and artificial aspects of their environment than modern person can 'escape' from the earth they where born into. It follows that any member of your station will be just as capable as patching a leaky roof as any other. They don't need to be 'trained' in a classroom or 'motivated' by debiting their service. They fix the leak or THEY SUFFOCATE. Instead, I'd flip this 'rule' on it's head and say that, after three generations, your colonist have vastly IMPROVED their condition and are likely to produce far superior space station construction and maintenance personnel than earth can hope to struggle to produce. The only society NOT likely to survive, maybe, is a despotic theocracy which might seek to obfuscate the workings of the space colony in someway, and replace that knowledge with a dangerous and misleading myth. So long as this can be avoided, you can craft whatever society you want. PS: Atomic Rockets! best website EVER [Answer] **Learn from nature** First off, if this issue matters, then you're making it too hard to survive on your generation ship. If we look to nature, we don't see a system which catastrophically fails if one fox decides to be an herbivore. The fundamentals of survival are intentionally spread and made easy. Life may be horrible if all the foxes stop eating rabbits and the rabbit population explodes, but life keeps ticking. If you are dependent on every single generation doing exactly what you thought they should do when the ship left its homeworld, you've set yourself up for disaster. Second, teach people to seek balance, not always the most extremely optimal result. Sure, you can get away with exactly 71 algae sludge farmers, but maybe you plan for 75. Then, when 3 of them choose to be artists instead, you still have enough support. More importantly though, is how you handle a mass exedous. If 10 algae sludge farmers decide that algae farming is horrible, you'd still be in trouble. However, if you taught them to seek balance, maybe (just maybe) 5 or 6 of them will see that food is important, and choose to farm potatoes instead. And maybe, people will see that the balance has shifted, and be more frugal until the vaunted position of algae sludge farmer is prestigious enough to at least bump their ranks back up to the requisite 71. However, had you brought only 71 on to begin with, you'd find you had no room to balance. You needed 100% of those who left the trade to return to the trade, or you're under quota. Third, ditch the classic machinery. One of the classic arguments in such a generation situation is that they forget to maintain key hardware, so future generations get screwed. The solution to that is also found in nature: hardware that maintains itself. If you concentrate on hardware which can repair itself and can be produced mid-flight, you can afford to lose a lot of hardware. I'd make my generation ship out of almost entirely organics or organic-like machines, so that the ship survives even if the crew fails to do their job. [Answer] For knowledge to survive through generations, people need to take pride in their craft. You need to motivate people by making it so that what they do is not just a job, but rather an art, a craft, something they can take pride in, something that affects other people, and something only they can do. You need a tradition. For an algae farmer, each generation need to show to the next generation how the produces from the farm affects the society, how the result of a bad crop directly affects the health and happiness of the rest of the crew, how a bad crop causes half of the crew to become sick. You also need people to be able to make mistakes without devastating the entire mission, so you need just enough redundancy, enough to maintain the crew through a bad period, to show the effect of laziness from time to time, though not too much that it causes people to depend on the redundancy. You need a tradition whereby people don't just pass on their skills, but also their pride to the next generation. They may pass on tales and mythos about other ships that didn't survive because of fatal mistakes made by people within their craft. These mythos are intended to make the successors appreciate their work, and to take it seriously. [Answer] The answer, ironically enough, is staring you right in the face (this week), from a sidebar advertising, from Meta site: > > Fortnightly topic challenge #11: **Religion** > > > :) Seriously, what's one sure-fire way known **in human practice** to motivate multiple people to maintain any sort of equilibrium or in general behave in somewhat predictable and socially beneficial ways; and to pay attention to small details, for long periods? That's right, **religion**! This is a well known SciFi concept (I won't dignify myself with trawling through TVTropes, but one example from a work I absolutely love is David Weber's "Heirs to the Empire", book 3 of "Armageddon Inheritance", aka "Dahak series". Or, more recently, Weber's *Safehold* series). Create a religion, whose tenets include: * Requirements for habitat maintenance as one of commandments Judaism excelled at [making people obey tons of](https://www.jewishvirtuallibrary.org/jsource/Judaism/talmud_&_mishna.html) anal-obsessive, frequently hard to comprehend, and definitely frequently annoying and hard to obey rules (no offense to [YLOR](https://judaism.meta.stackexchange.com/a/594/2736)). **FOR THE LAST 3000 years, give or take** - with only the last ~150 years producing the ... say, 150th generation that invented Reform Judaism so they can get away with not maintaining algae sludge! * Requirements for keeping your place in life. Reincarnation is there to ensure hope of future improvement. Hinduism succeeded in this by applying concepts of [Karma, reincarnation, and castes](http://philosophy.lander.edu/oriental/caste.html). * Severe respect for hard work Calvinism, Puritans, [and other assorted Protestant flavors excelled at that](https://en.wikipedia.org/wiki/Protestant_work_ethic). * Add commandments about having to learn and teach important subjects Any number of religious historical examples, from Judaism, to Jesuits [Answer] Well first you would need a large enough pool of people living in this habitat that you can pull the needed aptitudes and skills to minimize 'forcing' people into jobs they would hate. Then take something from the military. many of the 'boring/bad' jobs will be passed around. Everyone gets 'KP'. Someone is in charge say the 'cook' and they get a revolving host of helpers. So the cook makes sure the meal is done correctly, but doesn't have to do all the work themselves. On top of that everyone gets an appreciation of both the effort put forth and knowledge on how things work that allow them to live as they are. Then the amount of 'KP' you get might also be based on what your other duties are. If you don't want to do 'anything' then half of your time might be 'KP' so it becomes your defacto job. If you are in charge of keeping life support up and running, then 1 day a month or a quarter might be more appropriate. Like anything this could be abused to allow people who think they are too important to be bothered with it, might try to get their name off the list. So the lists need to be kept public as well as past records. So everyone can 'audit' the duties. Of course days can be traded. Now with this, when important jobs that need more than physical labor are not filling well, then comes in the 'bidding' to raise or lower how many days of 'KP' the position is required to donate. If everyone wants a nice cushy job, then maybe 1 day a week is 'KP', if no one wants to touch it, maybe 1 day a year of 'KP' to encourage others to go down that path. In call cases someone needs to be in charge of every critical system (which really is all of them) and are expected to keep things in 'ship shape'. [Answer] There are two parts to the problem: short-term issues and long-term issues. # Short-term issues Part of the problem of the Three Generation Rule is that people like procrastinating. Why do today what you can put off 'til tomorrow? Or, in this case, why do today what you can put off 'til the next generation? If I understand correctly, though, people will start to do things they don't want to do when it becomes apparent that if they don't do them immediately, they will die. The solution to these problems, of course, is to do the maintenance continuously so that this stage of crisis is never reached. So there must be an incentive to do the maintenance. This can be accomplished by one of two systems, which are [positive and negative reinforcements](http://en.wikipedia.org/wiki/Reinforcement#Reinforcement). As an example, I'll say that there is a micrometeorite shield that needs repairs (not a particularly difficult or disgusting task, admittedly). Here's what happens when Spaceman Spiff is needed to fix it. ### Positive reinforcement > > **Computer:** Spiff, you didn't do the repairs on the micrometeorite shield, like you were scheduled to do. > > > **Spaceman Spiff:** I'll get to it. I'm busy, and I have some other things to do. > > > **Computer:** You'll get an extra helping of chocolate cake tonight if you do it. > > > **Spiff:** I'm on it. > > > The problem with this implementation - besides the fact that they will one day run out of chocolate cake - is that people could learn to game the system. If they wait until to do a task, they know they will be rewarded in the end. A better way is to simply make a long-term promise: Fix the shields whenever you're supposed to, and you'll continue to get extra helpings of chocolate cake. ### Negative reinforcement The problem with positive reinforcement is that there's no immediate downside to not making the repair. When the repair really, really, really needs doing at the last minute, there is a motivation: death. This is simple logic; If Spaceman Spiff doesn't do X, Y will happen. In this case, Y is death. The system can be applied to short-term maintenance, too. Let's go back to an alternate version of the conversation. > > **Computer:** Spiff, you didn't do the repairs on the micrometeorite shield, like you were scheduled to do. > > > **Spaceman Spiff:** I'll get to it. I'm busy, and I have some other things to do. > > > **Computer:** Spiff, you might be interested in knowing that between the micrometeorite shield and the main structure is a very, very thing layer. It just so happens to contain some electrical wiring that is associated with the heating system. If there is some damage to the shield, then the main structure will not crumble or be irreversibly damaged. That will happen quickly after. But what *will* happen is that those wires will be irreversibly damaged, which will cause the average temperature in the crew quarters to drop by about - oh, I don't know, about ten degrees. This won't kill you - no, not by a long shot - but it will make some sleeping periods very cold. > > > **Spiff:** I'm on it. > > > This time, there is a definite consequence to Spiff not doing the repair, and this consequence will make him and his crew members very, very unhappy. This system will probably work better than the positive rewards system. You could apply this to other tasks, too. For example, if the algae are not introduced to nutrients on a regular basis, then perhaps other organisms added to them could emit large quantities of gases that will make life quite unpleasant. Or if the sewage system is not cleaned properly . . . well, the effects of that are automatic, providing you figure out how to install some strategically placed vents. # Long-term issues This is trickier. It's one thing to motivate someone to "feed" the algae. It's another to convince someone to spend their entire life farming algae sludge. I need a bit more time to finish writing this one. In the meantime, I'm all ready to address any issues with the first section. [Answer] The cultural requirements of the crew/colonists is completely dependant on the design of the ship. Let's start with the ship. **Dr TechSkill or How I learned to stop worrying and love automation** There's two ways you could store the information needed to make a self-healing, self-sustaining biosphere for a generation ship. The ship designers can design a ship driven by biological means or by mechanical/electrical means. Either your ship can be repaired by biochemical machines or they can be repaired by metallic nanomachines. A human crew can only be responsible for macroscopic repairs, ever. Consider the scale of repairs to be made. **Scale of repairs** The largest component of this ship will be the hull. It needs to last the entire trip but major repairs shouldn't be necessary because there are few to no moving parts. On the other end of the scale, the ship will make innumerable stress cracks and metal fatigue that should be fixed. What do you want your crew working on? Which activities are going to drive them nuts faster? Which ones will make them curse your name through the generations for making them do stupid busy tasks? **Is robust enough?** A ship that is merely robust will eventually degrade and fail. We see this in well made and well maintained cars. They last for a very very long time but even with the best preservation techniques, reach a point where to keep them in shape means to make them museum pieces. A generation ship cannot afford museum pieces for critical hardware. Therefore, the ship must regenerate itself. This is easiest to imagine if the ship is biologically based though it's no different than if nanomachines performed the repairs. Each subsystem is an 'organ' with multiple redundancies to improve fault tolerance. As the organ operates, the "cells" of the organ repair damage as it happens, without intervention by humans; much the same way our bodies regrow the linings of our stomachs as we digest food. In the event of complete organ failure, it is broken down into constituent materials and a new organ is regrown. This process of renewal can occur at every level, from the fixing smallest hairline cracks to repairing hull breaches. This manner of renewal must happen, especially without human interaction. **Like a surgeon, cutting for the very first time!** Humans then play the role of surgeons to the life form that is their ship. The finer grained repairs of the ship are handled by the ship, just as the human body will repair skin cut during surgery. And while the ship could repair a major hull breach on its own, it may not be able to do it in time to maintain a livable atmosphere for the crew. Therefore crew action is needed to patch the breach then let the ship repair the finer details. **Who wants to go to Med School?** Oh! Oh! Pick me! Pick me! Everyone on board knows that the ship surgeons have the most dangerous and most important job. They are the firemen, and engineers and as such, the prestige is high. Even in a society of equals, competition for a position like this will be intense. There will be no shortage of candidates who want to learn the skills required. Build up a school to train them and provide facilities, such as the ship can support, for additional research into how to improve the ship's efficiency. A socialist democracy perhaps would be best where everyone is invested in decisions and everyone's needs are taken care of. Let there be an exceedingly strict divide between governance of the ship and it's crew, and the colonists. As in ocean going ships, the captain is the ultimate authority on all matters. However, the colonists should have their own leaders and hierarchy so the captain can focus on running the ship. [Answer] **The Survivors** They are the result of a thousand failures, a culture built on the blood, bodies, and bad air of those before them who refused to see. The descendants of those who saw what was coming, and left early to protect their own. They learn the lessons on their parent's knees. Of dedication, of competence, of carefulness. They know the importance of maintenance, of environment, of planning, as things seeped into the bedrock of their culture. They know these things as custom and law, so basic that they are beyond simple religion. They are taught about the Bureaucrat as children, who killed his Home through neglect to a get a bonus he would never spend. They are told of the Lazy, and how the filter he left unchanged filled the air with death and killed him, and his children, and his children's children. They are told of the Fools and the Optimists and how they met their ends. And they know of the three-generation rule as a cautionary fable. [Answer] ### Build It as a Culture/Habit The military does this a lot. There's a reason why everyone is forced into a certain routine. It's good for everyone. Anyone who breaks from this routine is disciplined. They can train school dropouts into organized officers. They deliberately design everything to minimize mistakes. Codes like Alpha Bravo Charlie are picked so they don't get confused with other words, even with different dialects. They use 1300 instead of 1 PM, so people don't forget the PM. Another example is surnames. People's names indicate their role and expertise. If there's no bread, blame Bob Baker. If there are no shoes, blame Michael Schumacher. An individual's status might be raised based on their responsibilities. Jane Algae and Raj Oxygen could have higher status than Albert Overseer. Society would make sure that these people perform their roles. Not doing their responsibilities would be a high taboo akin to treason. There are many of negative effects, but survival is at stake! ### Redundancy Any critical system has a lot of redundancy built into it. Spaceships, airplanes, nuclear power plants, dams. It would require a series of errors for the system to fail. Before it fails there could be multiple warnings, to wake people from complacency. ### Automatic maintenance Anything that could be automatically maintained would be. [Answer] My answer could be a little boring, but nevertheless I will give my opinion a try. Let's say that the population lives in a scenario where **machines** have to be mantained in order to avoid a structure failure (planet colony with no breathable atmosphere, space ship, etc.). You are supposed then to be setting the scenario in a most advanced era, where technology is very present in everyone's life. The first generation built sustaining-structures for all other generations to come and you say the the last ones would not manage to somehow understand that their life depends on it. *That is, in my opinion, because people's life DOES NOT immediately depends on it* People may forget, not know or don't want to know how a water-recycling filter works, because while everyone knows that shortage of water may be deadly, it is yet very different than having a gun pointed at one's head. What I am trying to say is that *the knowledge of immediate death* would make butts move. Now, let me combine some of the answers I've been reading until now and give you my "customized" answer: If the first generation is so smart, they probably already dealt with the following generation problem as well. Since they know the population would depend on machines, why not creating an *ad-hoc* religion which **revered** machines? Now, the perk of religions is always that women and men would want to elevate themselves to have a glimpse of their gods (paradise, nirvana, etc.), so why not **installing** pieces of machines inside population bodies (who said "mind control"? - in this case every possibility of "heresy" or "atheist" would be eliminated - ) in order to make people feel *baptized* ? If someone learns to live with implants that produce pain if a machine is "suffering" and needs to be repaired *(the sewage-filter god is angry)* , he/she would probably take it as a holy duty to implant infants with the same tech, so that the generations problem won't be a problem anymore. [Answer] This is an economy question. Basically, there has to be an incentive for maintaining the colony, just like there are for nation states (national pride, safety, welfare from the state and many other things I can't think of) and incentives for people to personally better themselves. This is not an easy question though, I would argue you're very close to the holy grail of economics; how do we make people produce stuff we need indefinitely, so there's never any recession because the consumer demand is always high enough to put the producers to work and there's never any starvation because the producers always live up to the consumers basic expectations ("starvation" being applied loosely, meaning a child who doesn't get any adequate entertainment for example is starving). You have to make the colonists work give them [dopamine](http://www.sciencedaily.com/releases/2013/01/130110094415.htm) or constantly make them confront the consequences of not working enough (people were in contact with death multiple times during foraging times) or the society is going to fall apart. * **[Gamification](http://www.researchgate.net/publication/256743509_Does_Gamification_Work__A_Literature_Review_of_Empirical_Studies_on_Gamification)** is one way. At Stackechange, we're doing tons of stuff for free simply because we get the acknowledgement from our peers through badges and rep points. Only problem; what happens to the losers? And how do you deal with depressed losers feeling so bad they don't want to play anymore? Darwin explained what could happen, the question is if you're comfortable going through that particular route? Possible darwinism applies to every suggestion given. * There's also the **classic economic theory**; [compensation as incentive](http://pup.princeton.edu/chapters/i7311.html). Maybe the harder you work, the more dopamine you get in your system, or the more dopamine producing stuff you can afford. The question is, how do you prevent people from gaming the system? Purely chemical ways to get dopamine is practiced by drug addicts, gym addicts, alcoholics and others while dopamine produced through results can be abused by unscrupulous business people, despots, bullies and others. These are obviously people who have taken it too far and are not in the near majority, many of us dabble in chemicals like alcohol or trash talk while winning at sports, but the risk is always there. How do you deal with them? * People have already mentioned **religion**, and a sense of purpose can absolutely produce dopamine and therefore motivate people. Some have mentioned cults, and they are corrupted good willing people, no doubt, but churches who voluntarily hold soup kitchens, work their ass off to read large tomes of lore and spread the word down through generations, travel thousands of kilometers for pilgrimage and fight oppression because they believe in such a thing as right or wrong detached from majority opinion. But, how do you make sure everyone is on the same page? Words are really hard to make unambiguous so someone, or some people, have to be named "chief interpreters". That's a lot of power vested in these people, and just like classical economic incentives, this can be used for abuse, no doubt. But, a sense of purpose need not be rooted in religion at all, but instilling the belief that something is really important is hard, let alone maintaining that belief through generations. If these are humans you're talking about, I do think that you can make a colony last beyond three generations with any of these as a foundation to maintain the colony. But don't expect that there will be no conflicts what so ever. Sure, just like water cooler trash talk, they might not destroy people's lives and still keep the crew focused on getting the job done but if you want absolutely friction free, effective and productive colonies with no internal threats, automate everything. Really, I can't see any other way other than winning the Nobel Prize in economics or engineering humans to produce dopamine in a way that's more easy to bend to the benefit of the colony. [Answer] *Assign jobs*, *train skills*, *rotate jobs*, *manage morale*, rinse, repeat. I believe the Fallout franchise, and in particular, *Fallout: Shelter*, is a good illustration here. In the world of Fallout; [a nuclear war occurs in 2077](https://www.youtube.com/watch?v=nvqm_pPD-aQ), but not before the "good people" at Vault-Tec create and deploy a number of Vaults (their term for Fallout Shelters), around the United States. All of this is flavor, I believe, for the main game mechanic in Fallout: The **SPECIAL** system. This is basically your standard RPG-style statistic system. In the SPECIAL system, every human is ranked from 1 to 10 for each of seven individual statistics: Strength, Perception, Endurance, Charisma, Intelligence, Agility, and Luck. These stats affect a variety of things throughout the games, from damage dealt and received, to resistance to damage or fatigue, to how much you can carry or how fast you learn skills. Certain outfits may reduce or increase these statistics, and they can also be increased through training. The important part, though, is how they are implemented in *Fallout: Shelter*. In *this game*, you are the Overseer of a Vault (for the most part, a closed environment, much akin to a spaceship), and so, you decide which facilities to build in what locations, and whom should be sent to which room. The latter task is made much simpler by the definition of a certain prominent skill type assigned to each room. For instance, the Power Generator room is better served by individuals with higher Strength, the Water Treatment facility increases output when staffed by those with better Perception, etc. Additionally, individuals in the game seem to prefer when they are sent into rooms that match their highest-level statistics. Managing Vault-dweller's happiness is a very important aspect of this game, just as managing a spaceship-dweller's happiness would be in real life. According to the in-game manual: "A happy Vault runs more efficiently and produces resources faster." In the game, as in real life, there are [a variety of ways](https://gamelytic.com/fallout-shelter-dweller-happiness-guide) to keep people happy. The main ones include: * Keeping them *healthy* * Assigning them to *a job they enjoy* * Successfully meeting *deadlines* seen as important to that job (where the Luck stat comes in) * Giving them *time off* * Assigning them *where they can converse with someone of the gender of their sexual preference* * Allowing them to *have babies* * Promptly *disposing of dead bodies* In real life though, you might prefer a variety of jobs that play to your strengths, or even a few that don't, so accounting for 'desired jobs' should also be taken into account. So I guess my answer to the question is **A happy society**. I know Happiness has been mentioned in a few other answers, but not as central to the theme. If any closed environment is to be successful long-term, keeping people *sane and happy* is the most important thing. If anything can or should be automated, it should probably be the system that gauges skills/preferences and assigns jobs, to prevent [the sort of corruption seen in Vaults](https://www.youtube.com/watch?v=Q2RXYXdY3Og) in the Fallout Universe. And when it comes to space colonization, this standardization of personnel management is increasingly important the farther from Earth you travel, since messages from mission control will take longer and longer to arrive. The main foreseeable problem after that would be faith in the system, so people would need to be reminded of the potential for human corruption. Though I'm sure sending them off with a nice databank of Earth's finest works of post-apocalyptic science fiction would help with that. *Or just let them play Fallout.* [Answer] It need to be a natural group like bushmen in Africa or jungle strain in the Amazonas with a strong cohesion and a fair religion that will guide them through the generations, since the genetic drive of rival and a liberal approach to competing would disunite the group. The young people must hear the same story from all adults, the same story as the adults once heard when they where young. Development would be their greatest hazard. [Answer] I think you might need something like the British aristocracy, which maintained large estates/fortunes for centuries. Individual families might fail due to one generation being spendthrift, but they'd be pretty much cast out of the system, and the assets would wind up with someone newly ennobled. ]

[Question] [ **Do we have the technology to go to the Moon now, and stay this time?** I'm not talking about the political will or economic rationale for doing so, I just want to know if there are any unsolved (and difficult to solve) problems that would prevent us from doing so in the very near future. If you're hurting for a cap on spending, let's say a state or company consortium were willing to invest a trillion dollars every decade for 3 decades into the project, about the cost of an Iraq war or two. I've recently asked a question about [**lunar space elevators**](https://worldbuilding.stackexchange.com/questions/26578/can-we-build-a-space-elevator-on-the-moon-with-present-technology), and it appears that they would be quite viable. If that's the case, a persuasive argument could be made that the first power to colonize the moon would get a decisive lead in access to space by colonizing the moon and using its physical resources for the infrastructure build-out needed to lay claim to the rest of the solar system. **EDIT**: To clarify the scope of the base, I'm thinking a facility that's as automated as possible, with a staff of as little as 100 people, designed to churn out refined materials from lunar ores for deploying vast solar panel fleets into space, and to use and maintain lunar space elevators for this purpose. [Answer] **No, not yet** but we are getting there. The technologies required to achieve a permanent moon colony are in reach but even with effectively infinite investment, the problems to be solved are *hard*. A number of problems have yet to be solved, namely, shelter construction, cheap high capacity lift capabilities, low gravity manufacturing, low gravity refining and there are probably many others. Without these basic facilities/capabilities, a lasting colony on any extraterrestrial body won't be possible without heavy resource infusions from Earth. Developing the automation so a robot can do them will also be tricky if for no other reason than developing advanced robots is *hard* and the inability to directly test the behavior of a low-g industrial robot while on Earth. ## Shelter Construction The field of robotics is advancing quickly and the ESA is working on a project to build [Lunarville](http://www.businessinsider.com/european-space-agency-plans-to-build-lunarville-moon-habitat-in-2024-2015-6). They expect something in 2024. Granted, large investments would hurry this research along but as of this writing, we still don't have an automated way to build a shelter on the moon. ## Cheap Lift Capacity SpaceX's Falcon Heavy is coming in 2016. If this proves economical and reliable then getting lots of material/equipment/supplies to the moon shouldn't be too difficult. (2022 edit): Falcon Heavy ended up not being a thing. Maybe Starship will offer the kind of lift capacity required to make this whole enterprise go. ## Low gravity refining/smelting The [composition](https://en.wikipedia.org/wiki/Geology_of_the_Moon#Elemental_composition) of the Moon is similar to Earth, so there's plenty of oxygen, iron and aluminum to be had. The problem is how to refine those materials into something useful for manufacturing. It looks like it's possible to smelt lunar mare materials based on [this paper](http://adsabs.harvard.edu/full/1992lbsa.conf..411H) but the actual implementation will be complicated. (It took thousands of years to get iron smelting right on earth because it's hard. Modern science makes it easier but it's still hard.) New smelting equipment will need to be designed, tested, lifted and installed. 3D printing of new smelting equipment on the moon will greatly reduce the cycle time required for improving existing equipment. ## Low gravity manufacturing Whether this is harder or not will depend on the manufacturing technique in question. I expect that normal machining operations will perform much as they do on Earth with the exception that extra care will need to be taken to prevent metal chips from popping into places they shouldn't go. Also, extreme care will need to be taken in regards to particulates control. The reduced gravity of the moon means that larger particles will stay aloft for longer. ## Energy Generation Solar cells are going to be heavy. Let's do a molten salt energy storage system heated by large field of Mylar solar reflectors instead. Mylar doesn't weigh much for the surface area and in a hard vacuum, shouldn't tarnish much, if at all. Both solar cells and molten salt energy storage are in production/development now. ## Economic Discussion If a lunar colony is to survive, it will need to generate an economy. Whether this is based on resource extraction or high tech manufacturing or a mix of both will depend on the specific technology available and which of the above problems are solved first. With a thriving economy, it won't be difficult to get volunteers/victims to move out to the colony to try to strike it rich. As each new batch of miners/engineers arrive, they make the lunar economy grow and increase demand for goods and services. People need: shelter, food, tools, mining/energy production. Shelter is address above, food is a solved problem (IMO), tool development will require smelting and machining of metals. Involvement in any of these basic industries generates value that an employer/buyer would be willing to pay for. As long as there's money to be made and a stable economic environment, a self-sustaining lunar colony is doable. It'll take a long time because economies take a long time to build but it's definitely doable. [Answer] The [Apollo program](https://en.wikipedia.org/wiki/Apollo_program#Costs) cost 25.4 billion US dollars. In today's money, that's about 150 billion dollars. So if you are willing to spend trillions of dollars, **it is absolutely doable**. Some problems would need solving though: * Radiation. The Moon lacks atmosphere and magnetic poles, so the surface radiation is very heavy. This issue could be solved by building underground. * Low gravity. Prolonged exposure to low gravity would have - practically yet unknown - effects on the health of the crew. (Most likely *osteoporosis* and *circulatory disorders*, but - since prolonged exposure to **low** gravity can not be tested withing Earth circumstances we don't yet know it.) * Oxygen supply. There is no evidence that there is enough bound oxygen on the Moon to supply a colony. (If they could only find a huge crater filled with ice...) Some of the oxygen could be recycled, but it wouldn't be a 100% efficient process. * Water supply. (See above.) * Energy supply. (See above.) Theoretically there are two ways to solve the energy needs; atom-reactors (we don't have working fusion reactors yet) or solar panels, and each of them has their own caveats. With no atmosphere the surface of Luna is constantly bombarded with dust and tiny stones rendering the solar panels inoperable, and atom-reactors are huge, heavy equipment operating on huge, heavy fuel cells which has to be transported from Earth for a literally astronomical price. * Food supply. (See above.) Okay, food could be produced in aeroponic gardens (hydroponics are no option since every gram of water takes thousands of dollars to be transported there). [Answer] In terms of feasibility, one of the issues in the Apollo program of the 1960's was the issue of where to go and what to do next. Designs for a lunar base were under detailed study by NASA and its contractors (indeed the US Army Corps of Engineers had studies a military base on the Moon in the 1950's as part of Project Horizon), and part of the charm of the movie "2001, a Space Odyssey" is that the giant moon base, space station and deep space exploration of Jupiter were all based on then current NASA studies, and all judged feasible by NASA given funding and political support. [](https://i.stack.imgur.com/2k2XE.jpg) So the short answer is "yes", this is possible given 1960 era technology. The big sticking point is that even now, there is no effective means of creating and running a closed life support system. With current technology, it seems possible to recycle about 80% of the air, water and food, and "topping up" the inevitable losses through imports from Earth or perhaps the asteroids and NEO's. Colonists or astronauts working in such a space will have to be constantly on alert for the system crashing as it exceeds certain parameters. [Answer] **ESA PLANNING TO BUILD AN INTERNATIONAL VILLAGE… ON THE MOON!** This is the title for an article in [Universe Today](http://www.universetoday.com/127648/esa-planning-to-build-an-international-village-on-the-moon/). It's not a fantasy speculation. ESA is proposing this to other big Space Agencies (such as NASA) to make a permanent colony on the moon. [](https://i.stack.imgur.com/5lGZ8.jpg) The idea is to take advantage of [3D printing technology](http://www.esa.int/Our_Activities/Space_Engineering_Technology/Building_a_lunar_base_with_3D_printing) to cover (using Moon dirt) the base domes. [Several scientists from the agency have come forward](https://www.youtube.com/watch?v=E-lq2ErdlXY) to explain [what are the difficulties](https://www.youtube.com/watch?v=pk9PWUGkz7o) and how are they to be solved. I don't think it will hold 100 people (perhaps a dozen) and the population certainly won't be permanent since [lack of sufficient gravity](https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_human_body) among other issues are hazardous to the human body. In any case this is not that far from the model you put forward. It already plans to use moon resources and although hardly independent from Earth is probably self sustainable for periods of months. What you suggest is a matter of scale more than a matter of technology (although take in consideration the humane aspects of leaving people on the moon for very prolonged periods of time). [Answer] ## Conditionally "Yes" A "yes" answer depends upon some assumptions: * Ignores the extensive *engineering* research & experimentation that still needs to be performed. * The colony requires some resources (mostly water) in situ (e.g. on Ceres or at the Lunar, Hermian, or Martian poles). ### Technologically Speaking By my definition, a permanent colony needs to self-sufficient for all of the high mass items that it might need to keep the colonists alive. The list of these items is 1. Air 2. Water 3. Food 4. Shielding 5. Thermal control 6. Power 7. Communications 8. Living space **Life Support** A working Closed-loop Ecological Life Support System should provide the colonists with all their physiological needs for air, water, & food. Viable designs for a [Closed-loop Ecological Life Support System (CELSS)](http://www.projectrho.com/public_html/rocket/lifesupport.php#id--Closed_Ecological_Systems) have been around for years (at least since the '70s). Closed-loop Ecological Life Support System (CELSS): [](https://i.stack.imgur.com/vH1WA.jpg) The [poor showing of the two "Biosphere"](https://en.wikipedia.org/wiki/Biosphere_2#Praise_and_criticism) experiments is not representative of Humanity's state of knowledge in this area. However, it did show that fluctuations in in/output of various components (e.g. Oxygen) over short periods of time can have dire consequences. The smaller the environment, the more drastic the consequences. Biosphere 2 had trouble dealing with daily fluctuations in $O\_2$ creation / $CO\_2$ extraction! This partially why the in situ resources are required. Until humanity finishes ironing out the complexities of closed-loop life support, the colony will require constant tweaking of its environment (add a little water here, take some $CO\_2$ out there, etc.). **Shielding** The space environment is very hostile to human life. One of the things that makes it so hostile is the radiation. The biggest concern for colonists will be solar storms (coronal mass ejections & flares) which send much higher densities of protons sleeting through the Solar System. Other types of radiation are a concern (X-Ray, UV, "Cosmic Rays", etc.). The best shielding against the solar wind will be a mass of low atomic mass nuclei between the colonists and they radiation. A resource that should be available at our colony is large quantities of water. Thanks to the hydrogen in that water, it makes for a very convenient radiation shield. Put the colony in a Lunar (or Martian/Hermian) crater and covering it with a dome. The dome should be made of two layers sandwiching 32 feet of water. This will provide the same protection as the Earth's atmosphere. Incidentally, the mass of water, helps reduce the stresses on the dome since its weight counter-acts the interior pressure of the habitat. The other nice aspect of the water shield is that it provides a great thermal reservoir helping to regulate the temperature between day-night cycles (especially good for a Lunar colony). But we'll need more than radiation shielding. We also need micrometeor shielding. The most effective system developed so far is known as [a Whipple Shield](https://en.wikipedia.org/wiki/Whipple_shield). How a Whipple Shield works [](https://i.stack.imgur.com/KCco9.jpg) NOTE: 1. Micrometeor impacts the outer bumper. 2. Impact creates shock waves through the impactor and the bumper. 3. Shock wave vaporizes impactor. 4. Hot plasma penetrates bumper but is "caught" by the second layer. **Power & Thermal Control** If at or nearer the Earth's orbit, then PV (photovoltaic) power generation is viable. Outside of Earth's orbit, it rapidly becomes impractical. Otherwise, you'll need to use nuclear. Since we haven't mastered fusion power yet, the reactors will need fissionable reactor fuel. Until the colony establishes its own Uranium ore mining & refining infrastructure, the fuel will have to come from the Earth. Power generation requires the ability to dump waste heat. If established on Mars, then the Martian atmosphere could aid in dumping waste heat. However, the Martian atmosphere is so thin that it should not be used as the primary means of dumping heat. I personally think that something similar to the closed-loop geothermal heating system would work quite well (run water through pipes buried in the Martian / Lunar / Hermian crust). Dumping the waste heat is a requirement for either power generation system. **Communications** Either high gain & high frequency radio or use optical lasers to transmit data. Since the colony and the Earth will both be in predictable locations, aiming should not pose a problem. **Living Space** If we are able to use the concept proposed in the [The Millennial Project: Colonizing the Galaxy in Eight Easy Steps](https://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps) of putting your colony in and around a "right sized" crater, then you can use the domed crater as your green space (recreation and plant growing). Regardless of where you establish your colony (Mercury's pole, Moon's pole, or Mars), the plants will require supplemental lighting. This can either be done with mirrors or by dedicated lighting fixtures. If there isn't enough space under the dome, then living and working space can be made into tunnels around the domed crater. ### Socio-economically speaking Harvesting raw materials from space for shipping back to Earth is a losing proposition. The margins on raw materials are so low that extravagant costs incurred to harvest them will always (foreseeable future anyway) make them too expensive to use on Earth. You will lose your shirt and everything else if you're planning to mine asteroids for precious metals. In fact the "shipping costs" associated with space travel make it very difficult for space created items to compete with terrestrial manufactured goods ... on Earth. The most realistic place to use goods made in space, would be in space. In this environment, the terrestrial goods must pay the exorbitant shipping costs while space manufactured goods would pay less. So in order to justify space infrastructure, we must have space infrastructure that needs our goods. It's a difficult Catch 22. I only see a few ways around the Catch 22: 1. Discovery that space can provide some unique and high profit item that cannot be created on Earth. 2. Build space infrastructure to service the Earth's vast fleet of Geosynchronous satellites 3. For our survival: to deflect an asteroid or evacuate some of the population Of these, 1. Could range from the highly improbable ("alien artifacts discovered on Mars!") to the reasonable ("only place to manufacture km length nanotubes is in zero-gravity") 2. is boring. 3. Many stories written about this. Perhaps one of the best scenarios that might come from this is the construction of two humongous (8,000,000 ton) Project Orion type craft for asteroid deflection. Asteroid misses us. We decide to use the ships to colonize instead. [Answer] A permanent base on the Moon would be PERFECTLY feasible. A permanent base *for humans* on the Moon, not so much. To assume humans are needed to carry out activities is a fallacy. Building a robotic base on the moon, allowing those machines to gather energy, recharge themselves, and then explore would be perfectly feasible, as ALL the technology to do this existed over 10yrs ago. Flying robots out to the moon has been possible since the Russians sent their rovers. We are good at making robots for Mars. The moon is closer and potentially easier to reach with a bouncing landing approach using armoured ballutes that jettison after landing. Some machines could be pure energy collectors, scattered across the surface like gas stations, constantly building up stored solar power or thermally derived power to deliver it to rovers, using wireless charging, that explore the regions between the sources of power. Mapping the moon for later mining would be automated, with the machines relaying their data to cheap orbiters, themselves both comms relay and Lunar Positioning System (LPS) providers. This would free up weight on the rovers otherwise used for bulky, heavy comms and navigation systems... for survey instrumentation instead. > > Whoever puts a comms and LPS constellation of platforms into Lunar Orbit would be able to charge later explorers to use it via licensing and also save them the expense of Moon-Earth-Moon signal relaying and navigation on the lunar surface. This part of the operation could finance the exploration AND the provision of the network of scattered energy stations on the lunar surface, another source of future income. > > > Using a distributed network of compact, mass-produced identical energy stations on the lunar surface, built on Earth and scattered across the lunar surface, would also free up each rover from having to carry their own bulky solar panels or power sources. This would allow vast regions of the lunar surface to be surveyed and/or explored quickly and at low cost to any participating nation willing to utilize the provided network instead of going it alone, with its associated cost. Using wireless charging, rovers might also charge each other, meaning rovers will be unlikely to suffer loss from unexpected losses of power due to unforeseen events, if their peers can 'carry energy' to them from some nearby recharging station. This behaviour can, of course, be automated. Thus, this makes a lunar 'colony' of machines more likely, cheaper and faster to create than any human colony, with all its inherent and complex needs for air, protection, shelter and water. All this, of course, with a view to later mining the moon by later automated systems. [Answer] **This is more of an issue of motivation and water than it is of technology.** This could be done, if there was a reason to do it. However, lunar water would be a huge plus which would make a great difference to the project. Water would be used for many things. **PROPELLANT** The dV to lift a payload into low Earth orbit is 9.3-10km/s. Assuming an exhaust velocity of 4.4km/s (typical for H2-O2 engines in a vacuum, rather high for a first stage but we'll stick with it for consistency) the initial mass / payload ratio from the [rocket equation](https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation) is e^(10/4.4)=9.7:1 That is, a 970 tonne rocket (including hydrogen/oxygen propellant) can lift 100 tonnes into orbit. Note that "payload" here is used in the loosest possible terms, as it includes all the mass of the rocket tanks and engine, in additional to the useful payload (though infinite staging would reduce this to zero.) A real rocket necesarily underperforms this. Taking [Falcon Heavy](https://en.wikipedia.org/wiki/Falcon_Heavy) (2 1/2 stage rocket using kerosene/oxygen) as a real world example: Specific impulse 311 sec x 9.8 = 3047m/s exhaust velocity calculated initial mass / payload ratio e^(10/3.047)=26.6:1 Actual initial mass / payload ratio 1463 tonnes / 53 tonnes =27.6:1 Getting to the moon from low earth orbit further impacts the mass/payload ratio. For the following [dV budgets](https://en.wikipedia.org/wiki/Delta-v_budget) we would have to apply a further mass / payload ratio, starting at low earth orbit, and assuming 4.4km/s effective exhaust velocity (H2/O2 engine) Low Earth orbit to: Lagrange points (where Earth and Lunar gravity are balanced) stopping and not merely flying through 3.43 to 3.97km/s > 2.18:1 to 2.47:1, depending on which point Low Lunar Orbit 4.04km/s > 2.5:1 Lunar surface 5.93km/s > 3.85:1 It's clear why the Apollo missions left the command module in lunar orbit with the fuel to turn around and go home (a burn of only 1.31km/s) and sent a separate module down to the lunar surface. Being able to make propellant on the moon would enable a lunar shuttle to meet an Earth supply ship, greatly reducing the amount of propellant required. We can actually do even better. [Apollo required only 3.05 to 3.25km/s](https://en.wikipedia.org/wiki/Trans-lunar_injection) (median 3.15, ratio 2.04:1) to achieve translunar injection, which in the case of Apollo meant a free-return figure 8 orbit round the back of the moon that would return to Earth without power if there was a failure (a trajectory decision that saved the lives of the crew of Apollo 13.) the lunar shuttle would have to chase after the supply ship, retrieve the payload and decelerate back to the moon surface. **In summary a vehicle to launch a given payload to the moon would be 3.85 times as heavy as a vehicle to launch the same payload to low earth orbit and would not return. With a lunar shuttle available that can be refueled on the moon and catch up to the earth vehicle, it would only need to be 2.04 times as heavy and would return to Earth on a free return trajectory.** Unfortunately, refining vast quantities of propellant on the lunar surface would require vast quantities of energy. Water ice deposits are most likely to exist in craters at the poles, and therefore have little access to solar energy. This would probably mean bringing a small nuclear reactor, similar to the ones used on submarines, to the moon to provide for the power needs. **CONSTRUCTION, COMFORT AND EXPERIMENTATION** **So I've just shown that the International Space Station could be moved to the moon, if we could accept a 2-4 times increase in Earth launch weights, plus the costs and risks associated with more complicated missions. It's doable, but is it worth it?** To go to the moon, you really have to ask if there is anything that can be done there that can't be done on the international space station. I don't see construction as a major issue. A decent survey would reveal caves and old [lava tubes](https://en.wikipedia.org/wiki/Lunar_lava_tube) suitable for habitation, with stable temperatures. An inflatable habitat protected by such a natural shelter would be ideal. However we are going to want to build some kind of structure sooner or later. Water would be useful in mixing whatever form of concrete was suitable on the moon (it would most certainly be different to regular Earth concrete, which requires CO2 to cure.) Water is a major factor in human comfort and experimentation. It can be used for recreation and bathing, as a working or heat transfer fluid in machinery and for chemistry. I don't see any practical need for it for growng of food (food can be brought from Earth if necessary) but surely a major reason for setting up a moon base would be to experiment with growing crops in an isolated system in low gravity. Finally, I din't thnk we'll be looking to mine the moon just yet, if ever. The cost of transport is just too great. **In summary, I think the most pressing thing would be to undertake a (robot) survey of the moon, in particular of its water resources, and then try to develop existing technology around it.** [Answer] One matter of particular importance is the amount of fuel you would need to launch that sort of stuff to the moon. According to [this](https://www.quora.com/How-many-pounds-of-rocket-fuel-are-necessary-to-propel-1-pound-of-mass-into-Earths-orbit-from-sea-level), about 90% of a rocket's mass is fuel, which is an ironic issue, as that also means the hardest part about launching a rocket is lifting the fuel. We only need to lift a small payload, which should require a certain amount of fuel. But the fuel itself has weight, which means we now have to add more fuel to lift the fuel we just added, which means we now have to add more fuel to lift the fuel we just added. Using that 90% estimate, this means that **about nine times the payload is required in fuel to launch stuff into space**. So consider the total mass of the outpost you want to put on the moon, multiply it by nine, and that's how much rocket fuel you need to gather. The space elevator you mention is likely a more viable solution--assuming the elevator's existence is given--since having a heavy enough anchor at the top eliminates the rocket propulsion problem altogether (but obviously the elevator needs to be built on Earth). But consider also that if we are building the space elevator for this one purpose, it is no longer a more viable solution. [Answer] > > the first power to colonize the moon would get a decisive lead in access to space by colonizing the moon and using its physical resources > > > What physical resources? Once, when I was once listening to the radio (probably [Coast to Coast AM](http://coasttocoastam.com) with [Art Bell](https://en.wikipedia.org/wiki/Art_Bell) in the late 1990s), someone from NASA was a guest speaker (whose name I absolutely do not recall). He explained why there was no lunar colony. I can summarize the argument with these three words: *What's the point?* The moon is a huge gravity source, which attracts asteroids that may smash into a lunar landing. The problem was anticipated to be more significant than on Earth because Earth has an atmosphere, which helps to burn up meteors. Mars, on the other hard, provides some interesting possibilities. It has more gravity (helpful for humans), and has an atmosphere. At the time, there wasn't much knowledge of existing water on Mars. However, the atmosphere could be used to start a massive chemical reaction that could have a byproduct of so much water that oceans could be created. This just isn't feasible with the moon because of the lack of atmosphere. So, for these two reasons (the lack of meteor protection, and the lack of water creatability), the moon's lack of atmosphere made the idea of a lunar space station undesirable. There was simply no compelling reason to place a settlement on the moon (which is why I summarized as "*What's the point?*"). Instead, a plan that would be just as worthwhile is the idea of a space station, which could move out of the way of an asteroid much more easily. And so, the International Space Station is what humanity actually did proceed to make. [Answer] Through the gov. I would say not at all. Through private corps I would still say no. However that no for private corps changes to a yes overnight once there is a way to profit off of a moon base. All the tech is available today. We need 1. Shelter. (Basicly a the same as the ISS but on the moon.) 2. Energy. We could use solar, nuclear, etc. 3. Food green house set up. [Answer] This could totally be done. The international space station is proof of our ability to sustain a long-term continuous presence in space. A moon base would be easier in some interesting ways. First to mind being gravity, rocks, and strangely, space. The high cost of launch would be a concern. You want to minimize it but that's the primary thing keeping us from doing it. It's hella expensive to launch a kg of cargo to orbit. Buut... at the investment levels stated, this is totally doable. Once investment is flowing and a commitment to the effort has been made I wouldn't be surprised to see a re-emergence of the harp/babylon projects for cheap launch of raw materials and supplies. (not people, unless you want to turn them to paste during launch, or build a really-really long launch tube with continuous or periodic acceleration... humm) <http://www.bbc.com/future/story/20160317-the-man-who-tried-to-make-a-supergun-for-saddam-hussein?ocid=AsiaOne> Good news though is the recent ressurnence in investment in rocketry is already lowering the cargo launch price per KG. SpaceX's successful recovery of first stage rockets has improved launch turn-around dramatically. And a renewed interest in commercial satellites indicates that progress is really picking up. One awesome quote I heard from a rocketry expert at Google was: "Rockets are currently built by hand by people with PHDs. What do you think will happen when we start building them the way Toyota builds cars?" But cost is no object right? On to the moon base. The base would probably be built underground for radiation and meteorite protection. (On earth our magnetosphere and atmosphere provide these protections, on the Moon we'd need to fall back on good old rock). Building in caves could also help by lending a structural foundation: Need to pressurize a cave? Blow up a big balloon in it and build an airlock around the door. Need a new room? Expand the cave or pressurize the adjoining one. The base would probably situated near the suspected water reserves in the bottoms of craters on the (south?) pole. If you'd like me to really run with this project I'd probably try to massively over-provision power, water, and air to prevent system fragility (the most delicate part of the plan is the people, they're also the most versatile repair machines so we'll need to take good care of them). I'd try to build the base around a Thorium molten salt reactor with fully duplicate power supplied by solar. <https://en.wikipedia.org/wiki/Molten_salt_reactor> I'm sure we could figure out something to do with the extra power and in the event of catastrophic failure, solar power would provide the buffer needed to work out a return to redundancy. I'm not a fan of batteries so I might try out a solar generated artificial hydrocarbon + fuel cell scenario. The fuel will keep in big tanks better than in batteries anyway. I might also try to deploy some huge skylights connected with fiber optic for passive lighting underground. Earth day cycles could probably be faked by shunting light to solar collectors during the "night". (how cool is it to imagine the massive mirror physically flipping the day to night, which also generates the spare power which will keep everyone alive if the unthinkable happens) I would build atmospheric life support around biological systems with mechanical backup. Lots, and lots of plant life (space is cheap remember? and water is pooled in the bottom of the crater). Added bonus is that the biological systems are good for recycling biomass and have some overlap with food production. I'd probably to deploy a lot of algae. I'd love some little cows too, but that's merely an aesthetic addition. <http://oregonstate.edu/ua/ncs/archives/2015/jul/osu-researchers-discover-unicorn->–-seaweed-tastes-bacon There'd be total recycling with periodic water and air true-ups to replace inevitable loss. I'm not entirely sure that we have the biological systems knowhow to do this right (I suspect we do, but it hasn't been tested) but your stipulated bottomless launch budget solves all problems. If we can't get it quite right we can re-supply from Earth (and if you need some extra drama you could couple an emergency with a shaking of faith from the earth-siders). Not only could this sustain a hundred people it'd be a plan that once it took root could expand nicely. Technological improvements which would could make matters easier: Robotics for manufacturing and repair (autonomous as much as possible) Space based resource mining smelting and manufacture Autonomous robotic mining and tunneling Materials science (better atmosphere containment, lighter radiation protection, awesome leak sealers) Of course rocketry and reduced cost space launch Improvements in closed loop biological systems ]

[Question] [ So, let's assume you've cobbled together an interplanetary empire without using transportation methods that violate causality or have the power to blow up stars. You may feel pretty proud of yourself, until you realize a big problem: ship aren't arriving when you think they should; some return just after they left, while others come back decades or even centuries behind schedule. You're about to order someone executed when a friendly scientist stops by and explains to you that time is *relative*, and it moves differently in different reference frames. That's all well and good, you say, but how is anyone supposed to keep to a schedule when no two planets have clocks that tick at the same speed? I realize that most planets would keep time their own way, and that should work pretty well for local schedules, but I'm more interested in how one could come up with an empirical measurement of time that everyone on all planets could agree on and use effectively. I'd really like it if both a source and a destination had one time that they could say a shipment would arrive, and that they could both be right without either side having to do too many calculations. Is there a way to make this possible? [Answer] This wouldn't actually be a huge problem. > > a friendly scientist stops by and explains to you that time is relative, and it moves differently in different reference frames > > > That's true, what's also true is most reference frames your civilization will move in are very nearly experiencing the same time flow. You have to get moving *very* fast in order to notice much difference.  At most you're going to be a few fractions of a second off here and there. We already adjust for this in [GPS satellites](http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html), so the equations are not difficult and our computers can easily figure them out and adjust automatically. If you know how fast you're going, then you can adjust for the time difference. **Too much work?** Just broadcast the local time for the system along with the location of the broadcast. If your ship receives the signal and knows where it is, it can determine the light distance from the reference signal and set the ship's microwave clock accordingly. You can even use multiple transmitting stations with known locations and set up a solar system positioning system, an SSPS. Using trilateration, your ship can then get location and local time from the same set of signals. [Answer] You've hit the nail on the head: in general, everyone's clocks will run at different rates, depending on their speed and position relative to gravitational fields. For example, we on Earth experience a different rate of time relative to satellites in orbit. However, just because time is relative doesn't mean that we can't know when a ship will arrive at its destination. We just need everyone to agree on one specific inertial frame that times will be measured in. Once everyone is agreed, you can just convert your own spacetime coordinate system into the reference frame, and then convert into someone else's coordinate system. We already do this in a simplistic fashion with time zones. I can convert 1:45 pm EST (UTC-5) to 6:45 pm UTC, then convert to 2:45 am (+ 1 day) Beijing time (UTC+8). In your case the math will be [more complex](https://en.wikipedia.org/wiki/Lorentz_transformation), since the time rate depends on relative speed, among other factors. The conversion will likely be handled by computer: you'll just ask your helmsman when you'll arrive at Alpha Centauri, and he'll read off his navigation display, "5 weeks, 3 days, 8 hours, and 31 minutes, and it'll be 6:56 on Tuesday the 22nd when we get there." The important thing to remember is that in any coordinate system, every point in spacetime will be mapped one-to-one to a unique set of coordinates. As long as you specify which frame your coordinates are in, there won't be any confusion. [Answer] ## Exactly as we do now While clocks at two locations will diverge, it will happen (a) slowly and (b) predictably. So you can treat them in the same manner as we treat time zones now, and possibly pick any of them as "privileged" - e.g. GMT or UTC. If you want to use any non-local time, it will not tick forward at the same speed (as on earth) and the offsets between different places will be variable, unlike Earth time zones (unless you simply discard all physics); so the calculations won't be feasible to make in your head - but they're trivial for computers. In the same way as now you can see currently (on e.g. hotel walls) multiple clocks that show 'London time', 'New York time' and 'Tokyo time', it would be trivial to have an (electronic) clock that would show 'Earth time' and 'Sirius time'; and it would be trivial to have your scheduling systems automatically convert everything to whatever time scale is most convenient for you and show it that way - again, as the current calendaring software does for meetings when participants are in different time zones. [Answer] The main problem is to establish a common time standard to base your local clocks off. Then it doesn't matter if your local time system differs from that (for example, you will want to base your planetary time scales on the rotation of that planet), since you can convert between whatever your local time is and "universal" time. Note that "universal" time also doesn't need to go at a rate of one physical second per universal second, so even things like planets close to heavy black holes (a la *Interstellar*) are not a problem for your time keeping. So what remains is to find a good source of a base time. One possibility for that might be pulsars. Pulsars are astronomical objects which basically provide a natural clocking. A disadvantage is that you only see the same pulsars if you are sufficiently close to the earth because you only see them if you're swept by their "light fire ray". So this method only works if your empire is not too large. But then, if you're bound by relativity, your empire likely won't be too large anyway. Anything inside the solar system definitely is close enough, and also the neighbouring stars are. Another possibility is to have a set of time signal senders, on/near different planets, and calculate the time from their signals by a GPS-like calculation. In other words, build up an interplanetary GPS (IPPS?) and use that both for determining your position and your canonical universal time. [Answer] If you can have some way of transerring data at decent speeds across planets/solar systems/galaxys you could have a clock somewhere (maybe a satelite) that acts as a base time to which all clocks can ask what "**U**niversal **S**tandard **T**ime" is it. If not, you could have a series of satelites that are kept in zones of similar gravity conditions so that time flows similarly for each of them and sync them every so often. Then every "clock" will check the UST against the closest satelite thus needing a less powerful data transfer. [Answer] If your empire is *really* big so that it actually spans multiple galaxies, you might want to base the standard clock on the cosmic microwave background. See for example [physics stackexchange](https://physics.stackexchange.com/questions/25928/is-the-cmb-rest-frame-special-where-does-it-come-from) Having chosen a standard clock, obviously you must then set a base time. As a galaxy spanning civilisation, you should have the technology to be able to use the start of the universe for that! Alternatively, a civilisation with FTL would likely use that technology to manage clocks. Special relativity considers how light signals are passed between observers to come to its conclusions regarding clocks. So it will depend on how break the law of the speed of light being limiting that will determine how to sychronise clocks. [Answer] Yes! Just "Make it so!" For storytelling that is really what generally happens. However, the only way there is a chance is if there is a instantaneous or nearly instantaneous form of communication. If it is known how long it takes to travel from one point to another, then knowing when the ship leaves, will give you a very good idea when it will arrive. It doesn't matter if the crew experience 1 week while there is a 4 week transit time for everyone else waiting, predicting when it should arrive local time should be 'relatively' easy (pun intended). Without near instantaneous communication, it is going to be a lot of calculations and assumptions. [Answer] You have to distinguish two notions: Local time and Global time. You only need to agree on the global time, and in a super-tech world where everything is done by computer, this can be as ridiculous number as "the number of seconds since 1st of January 1970". If two people who use different local time want to meet, they'll agree on the global time value, but the mindset will be their local time anyways, in a similar way as if you set a meeting with your friend overseas: you agree on a UTC time but note down the local time in your schedulers. Now to the technical part of the question: **What would be the UGC (universal galactic clock)?** The idea is the same as now: you fix a rotating object **X** that is stable enough, and you count its periods of rotation. This can be a galaxy (so in the end the typical lifetime of a human would be very small, 10-8 or even small, but who cares, it's just a number), group of galaxies, or whatever. **How would you refer to the time if relativity has to be considered?** Well, the time in any place in the space is measured in the following well-defined way: 1. You change your speed so that you are not moving relative to **X**. 2. You measure the distance *d* to **X**. 3. You get the timestamp *t* from **X**. 4. The value of **UGC** in your location is then *T = t - c d*, where *c* is the speed of light. Of course, in reality you keep track of your local time yourself to high precision (that's what you do now if you watch your clock), you know your movements so you can calculate the relativistic corrections. From time to time, you calibrate your clock with **UGC**. [Answer] There is no time in space because simultaneity is relative. <http://en.wikipedia.org/wiki/Simultaneity> In different frames of reference, a pair of events A and B can be seen to have happened A before B, or B before A, or simultaneously. It is only because our frames of reference on earth are so alike that we all agree on the order of events. This is not to say that events do not have causal relations. San Francisco could not be rebuilt until after the earthquake. I wonder if this would provide a basis for a tree-like, partially ordered notion of universal time? [Answer] If you know how much faster a clock is on planet A than on planet B, just compensate locally. You could also take whatever magic you use for non-causality breaking faster-than-light and adapt it to beam a time signal throughout the whole empire. Do you have FTL radio, or does information travel at the speed of the fastest courier ships? In which case a "crook" could keep ahead of the authorities by constantly moving as fast as the courier carrying news of his crimes. Or you could just have 'hyperspace' be filled with weird currents so that travel time is partly random. We coped with that during the Age of Sail. [Answer] You don't have to have the time stay the same for everywhere you go. It doesn't have to be 1AM on every planet and on every ship. That's funky and weird, and if there is some interesting orbital or rotational mechanism that would make that no longer feasible then here is what you do. **You keep the *units* of time the same.** Maybe one planet has the same number of hours as Earth. But there might be ones that have more or less. But you can give a travel time, not an arrival time. Since time is relative, and you're not setting up a literal *Universal Standard Time*, you can just use equivalent units of time measurement. How I figure this would work in your case is this: Ship leaves port at a certain time on one planet, will take some number of hours, days, weeks or what have you to reach its destination. If there is long-distance communication, this can be communicated to the people expecting the arrival of the ship. Now, the thing is that for us here on earth a day is 24 hours, but it also deals with the positions of the sun and the earth. So you'd have to strictly separate the meanings of the passage of time and the rotation of the planet in orbit. [Answer] In such an empire, surely you could define one pulsar visible from your capital planet as your "standard clock", and broadcast a tick count across your empire. This way everyone is synced to the same extremely precise clock corrected for communications delay. You can also sync up more than one observatories for extra precision. This way it is galactic day 102927 on every planet at the same time. [Answer] If your question was meant to be "What time zone is used aboard the International Space Station" the answer is UTC time. Other countries tend to use the timezone of the site from which their space craft were launched. Have assumed your question relates to actual space craft and not some of the answers offered so far. ]

[Question] [ In my late-Victorian world high-precision clockwork is highly available, but I am having trouble finding out exactly how precise their work could be. I have done some research on the subject, but cannot discover how people make more precise tools with less precise tools. If, for example, one simply translates large movements into small movements by gears or levers there is the irregularity of the parts themselves, let alone the movement, that would cause defects in the final product if my thinking is correct. This is how I am left with the question **what is the highest mechanical precision achievable in a late-Victorian setting?** I am aware that clockwork was already very precise, but I could imagine that it would be possible to have even higher precision, even though it may have been impractical at the time (e.g. watchmaker using pincers to place a dust-speck-sized cog on a shaft the breadth of a hair, missing and damaging the entire apparatus). EDIT: With precision I mean the smallest distance I can move a tool in a controlled and measurable fashion, e.g. a saw that lets me cut a groove x wide and y deep, x being the width of the saw and y being the 'precision' of the tool. [Answer] TL;DR: you almost certainly can't manage better than a ten-thousandth of an inch (~2.5 μm). The length and depth of the cut of your hypothetical saw could conceivably be accurate to this scale. Making a saw that could produce a width of cut this fine is probably impractical for your Victorians, if only for material issues. It is theoretically possible that diamond or ruby engraving tips could be up to the job, though. --- Your question is still slightly ill-specified, but the general issue of victorian precison and mechanical tolerances should still be answerable. Exhibit 1: [gauge blocks](https://en.wikipedia.org/wiki/Gauge_block), specifically those by [Carl Johannson](https://en.wikipedia.org/wiki/Carl_Edvard_Johansson). He apparently invented them in about 1896, and was granted a Swedish patent in 1901 a few months after Victoria's death (just sneaking out of the victorian era proper). His combination gauge block set included 49 blocks with thicknesses from 1.01mm to 1.49mm ([source](https://www.mitutoyo.com/wp-content/uploads/2013/07/E12016-History-of-The-Gage-Block.pdf), PDF). These don't represent the pinnacle of dimensional accuracy, but they are things that could be repeatably and reliably manufactured and sold as a practical and popular commercial product. Exhibit 2: [micrometers](https://en.wikipedia.org/wiki/Micrometer). The mechanical principles of these had been around for a long time before Victoria appeared, but micrometers for measuring the size of objects rather than the angles between stars appeared around the time of her reign or slightly before. [Henry Maudslay](https://en.wikipedia.org/wiki/Henry_Maudslay), who gave us screw-cutting lathes, had a [micrometer](http://collection.sciencemuseum.org.uk/objects/co59282/maudslay-s-lord-chancellor-bench-micrometer-micrometer) that could measure down to a ten-thousandth of an inch (~2.54 microns). [Joseph Whitworth](https://en.wikipedia.org/wiki/Joseph_Whitworth) had a device of similar capabilities in 1844, but built so that it was a bit less delicate and more practical for general workshop use. (You may also recognise the name Whitworth from the [British Standard Whitworth](https://en.wikipedia.org/wiki/British_Standard_Whitworth), a specification for screw threads. Not so important for ultra-fine machining, but *repeatably* being able to make high quality parts is also important and Whitworth threads were a part of how this was done in the Victorian era) Exhibit 3: Whitworth had also [devised a technique](http://ericweinhoffer.com/blog/2017/7/30/the-whitworth-three-plates-method) around 1830 for getting [surface plates](https://en.wikipedia.org/wiki/Surface_plate) (a particular kind of [reference plane](https://etshare.pbworks.com/f/Chapter%2014%20Reference%20Planes.pdf)) to a flatness of under a ten-thousandth of an inch. Surface plates are extremely important for the production of high-precision tools, because (amongst other things) they give you a way to create high-quality right-angle gauges. --- With careful use of these three items, you should be able to make very precise mechanical movements with your hypothetical saw. The issue of making a saw that's up to the job of making cuts this fine is left as an exercise to the reader! Victorian material science simply wasn't nearly as good as ours. Without our fancy metallurgy and ceramics technology, making tough cutting tools at this scale would be extremely difficult. Engraving features at this scale *might* be possible with a diamond or ruby tip, as for anything else material wear under use would ruin your precision very quickly. I can't find enough detail about Victorian micro engraving to say any more on what may or may not have been possible in this regard, though. --- For further reading on the issue in general, rather than victorian engineering in particular, have a read of [The Foundations of Mechanical Accuracy](https://epdf.pub/queue/foundations-of-mechanical-accuracy.html) (PDF, original book printed in the 70s). [Answer] Millimeter and possibly sub-millimeter accuracy was possible in normal manufacture. In scientific experiments far more precise *measurement* was made, but that does not equate to manufacturing and particularly to milling and machine processes. Here would be my candidates for common high precision manufacturing processes of that era. **The Janvier Reduction Machine** One of the most accurate instruments I've heard of (in common manufacturing, as opposed to special one-off scientific experiments) would be a device used in coin making (and some other fields) which controls a high precision lathe to generate a true size coin from mechanically scanning a much larger design form. Here's a link to a page on these devices : <http://www.1881o.com/reduction.html> These would reduce a template about the size of a dinner plate (perhaps a large dinner plate) to a standard coin size. The resulting coin would be used to stamp out coins. These machine were in daily use in the same role until relatively recently (and may still be in use somewhere for all I know :-) ). They allowed intricate coin designs (hard to fake by crooks) to be made by your beloved governments and make counterfeit coinage harder to pass. **Vernier Caliper/Scale** These are lovely (and still used) devices which existed before the Victorian era and allow high precision (and more importantly *consistent*) measurements to be made of object sizes. [Wikipedia](https://en.wikipedia.org/wiki/Calipers) can explain more about them. These gadgets are simultaneously loved and hated by engineers everywhere, loved because of their precision and hated because they sometimes bring bad news :-) . **The Common Screw** As odd as it may seem the Industrial Revolution depended as much on the accurate and consistent manufacture of well size screws (including their threads) as it did on any of the more glamorous engines and devices.[Wikipedia](https://en.wikipedia.org/wiki/Screw-cutting_lathe) has a page on these devices. [Answer] It depends on how you define precision, and also whether you place more importance on what would be commercially viable technology for mass production in the Victorian era, or what would be the best cutting edge fabrication processes available to the era's top scientists and instrumentmakers. For example, would the best precision of our era be represented by computer chips, or by LIGO? In the latter case, the answer would probably be "remarkably good precision". I think the best I can do is to cherry pick the era's most advanced instruments to serve as examples. So: 1. Diffraction grating ruling engines. These are a classic example of machines that push the limits of mechanical precision, and they also directly match your definition of "move a tool in a controlled and measurable fashion, e.g. a saw that lets me cut a groove x wide and y deep". By the end of the Victorian era, Henry Joseph Grayson had constructed ruling engines that could scribe gratings with 4700 lines per mm (ie, 212 nm pitch; each groove can roughly be assumed to be about 100 nm deep). Previous ruling engines were already pretty good, too. 2. Michelson interferometer The Michelson-Morley experiment was conducted in the 1880s, and represents one of the first and most important applications of the interferometer, which is still among the most sensitive measuring instruments in existence today. Their white-light interferometer was built on a sandstone block floating on mercury, which would compare well with setups in today's top academic labs (for precision if not for safety). Although they were looking for optical path length changes due to aether wind with fixed mirrors, their interferometer would have been sensitive enough to detect the mirrors moving by as little as 2-3 nm. 3. Whitworth's comparator Accurate micrometers for use in machine shops were already being commonly made in the Victorian era, but undoubtedly the king of this category of instrument would be Whitworth's comparator, built in 1871 and which could measure differences in the lengths of objects to submicron accuracy. 4. Chemical etching The smallest scale parts might be made by chemical rather than purely machining techniques. For example, platinum wire of about 1.5 micron diameter, known as Wollaston wire, was produced by the early 19th century. It is first embedded in silver, then drawn down, then the silver is chemically dissolved. If you wanted to make gears the size of specks of dust in the Victorian era, you could try to do it this way. (By the way, microscopic clockwork will make your clocks smaller, but probably not better at keeping time...) 5. Coating processes Although this isn't directly motion control related, it's also relevant to fabrication abilities. Electroplating became a mature technology during the Victorian era, and other thin-film deposition techniques such as vacuum sputtering were invented during that period. Electroforming was invented by 1840. These additive-manufacturing techniques allow the creation of extremely thin and uniform films and delicate thin-walled structures. A coating of silver on a glass substrate could be made less than a micron thick. Electroformed thin-walled metal objects could be tens of microns thick. 6. Bonus: Division of the circle In addition to length, another important thing is accuracy of angles. For example, if you have gear teeth, how evenly-spaced are they. The Victorians would have had little difficulty here. Already in the pre-Victorian 18th century, Jesse Ramsden had built division engines accurate to one arc-second. [Answer] How many zeros in your check book and how much time do we have? ***How do people make more precise tools with less precise tools?*** Precisely how you said: 'people' did it *by hand* (sometimes literally, polishing it with their fingers). *"You"* specifically, probably can't, which is why clockwork has always been a respected profession, and why gunsmithing still is. All well-made firearms are finished by hand to achieve the tolerances required. Which is done by dragging a file across the part, and then checking it against its mate. Over and over and over, until the smallest grit 'file' is simply a flat piece of a harder metal; **abrasive** number: +3000. That's why you're supposed to check that all the serial numbers of the parts match, because each one of them has been custom fit to the specific weapon. It becomes a question of **how fine you can hone an edge on your cutting tool, which is well beyond the limit of human dexterity to employ completely** no matter how good you are. To keep it realistic, I'd be looking for the smallest tolerances *ever achieved* in production, not what *would have been possible*, because that's determined by skill, dexterity, time, and 'number of zeros' until we're past the microscopic level. And then all sorts of problems start to crop up, like having a duty cycle of half a second, or being susceptible to even minor fluctuations in temperature and pressure or humidity, and the oxidation of materials commonly thought not to (the only one is gold, which is too soft to make parts). And it abrading itself. If you have to start worrying about the Casimir effect; you've gone way too far. **Motion control is easy: gear reduction.** But wanting to be able to wear it on your wrist and have it actually still work (*accurately!*) longer than half a second, (aka, miniaturization) is the problem, because even if you can *make* it, that doesn't mean it will *work*. At some point it gets small enough that the governor isn't reliable anymore due to the size of air molecules. For analog [clocks](https://en.wikipedia.org/wiki/Clock#Hairspring) it's ultimately **a question of how small you can make a** [**balance wheel**](https://en.wikipedia.org/wiki/Balance_wheel) (invented in the 14th century, the crucial advance that "finally made accurate pocket watches possible"), until the 1960s when electronics (tuning fork and quartz movement) became available. --- TL;DR: as small and accurate as you're willing to pay and wait for, up until the point that physics or material science says *no*. If you're Britain trying to solve the longitude problem at sea, that's *yesterday* so here's *three million pounds* to anyone who can. That's in adjusted dollars and it was [John Harrison](https://en.wikipedia.org/wiki/John_Harrison), inventor of the [marine chronometer](https://en.wikipedia.org/wiki/Marine_chronometer): "a timepiece that is precise and accurate enough to be used as a portable time standard". Have a demand, be willing to pay for it, and you can have your cake and eat it too... *within reason*, as dictated by the laws of the cosmos. Just don't forget to wind your watch and *'always dial one number higher'*. [Answer] ## Your thinking is essentially incorrect. Think of gears. You can stack a nigh-arbitrary number of gears together to achieve essentially any input/output ratio. As you suspected, the error will multiply through. but the net error will be far smaller than the reduction ratio. In cartoon form: one Angstrom plus or minus a hundred Angstroms is a pretty huge error and a pretty good precision. It all depends what you are trying to accomplish though. Accuracy is not the same as precision, and most things do not require or benefit from arbitrarily precise production. ]

[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. The Sun has nowhere near enough mass to enter the branch of stellar evolution that would lead to a supernova, fortunately for us. However, there are planets that orbit stars that are destined to go supernova. These planets might not be habitable, because such massive stars live and die within short periods of time, but they could still be interesting. Could a planet survive a supernova from the star it orbits? By "survive", I mean that the planet must have minimal orbital disruption and should remain in one piece and as undamaged as possible. The planet does not need to be in the [habitable zone](http://en.wikipedia.org/wiki/Circumstellar_habitable_zone) and survival of any life on the planet is not required. I leave it to answers to choose the mass of the star and planet, the orbital radius, and other relevant parameters, because not all combinations of these will result in the planet surviving. A good answer should determine the boundary line between survivable and unsurvivable scenarios. I'd still love to see an answer answer that discusses the effects of the supernova ejecta shell hitting the planet, and takes that into consideration when determining if the situation satisfies all the criteria for survivability. [Answer] **For big stars with the right supernova conditions, yes.** First a note. There are several types of supernova. In general, a Type I supernova doesn't leave much behind. Thus it is pointless to ask whether the planet exists with a minimal orbital disruption as there is nothing *to orbit*. A Type II supernova generally does leave something behind, like a neutron star or a black hole. This is what we're interested in here. --- To date, four [pulsar planets](http://en.wikipedia.org/wiki/Pulsar_planet) have been discovered. A pulsar planet is, of course, a planet orbiting a pulsar. [A pulsar is a remnant of a supernova](http://en.wikipedia.org/wiki/Pulsar#Formation). So, clearly there are planets which orbit what's left of a supernova. *However*, we have never observed a system which had planets, went supernova, and confirmed that the planets remained. So while we have observed planets orbiting stars which at some point went supernova, we do not know for certain whether they formed *after* the supernova or *before*. It is also impossible for us to know how the orbits or structure of the planets were affected. One [National Geographic article](http://news.nationalgeographic.com/news/2011/08/110805-planets-survive-supernovas-ejected-rogues-space-science/) reports that one newer model suggests planets could remain through a supernova: > > The new model also hints that—in very rare cases—some survivor planets may remain bound to the supernova remnants, finding new orbits around the neutron stars or black holes left behind by the explosions. > > > The [paper itself](http://arxiv.org/pdf/1107.1239v1.pdf) says specifically: > > Planets around > 20M⊙ black hole progenitors may > easily survive or readily be ejected depending on the core collapse and superwind > models applied > > > So really big stars that supernova might be able to hold on to their planets given the right conditions. [Answer] If we focus on the luminosity, ignoring shell impact, we can say that inner planets of the star-system do get destroyed whereas outer might survive (to some extent). **Brightness of a supernova** From [this question on physics.SE](https://physics.stackexchange.com/questions/61872/how-long-does-a-supernova-last), we get a rough estimate of the supernova shell/nebula peak brightness at about 60 days, with a variation of 3 magnitudes (a brightness ratio of 16:1). As a rough number, figure the average luminosity is 1/10 of peak for that period. So how bright is a supernova? Consider [SN2011fe](http://en.wikipedia.org/wiki/SN_2011fe), a Type 1a supernova which produced a peak brightness about 2.5 x $10^9$ that of the sun. To be conservative, let's figure on an average shell/nebula luminosity over 60 days of about $10^8$ suns. **Energy received by the Earth** Under ordinary conditions, the solar power intercepted by the Earth is about 174 x $10^{15}$ watts, and has an albedo of about 0.3. So the **total absorbed power is on the order of 6 x $10^{26}$ watts**. After the shell passes, the brightess will approximately double, and remain more or less constant for the next 60 days, since it is inside the nebula. Which leads to an absorbed power of 6 x $10^{26}$ watts for 5 x $10^6$ seconds, for a **total energy of 3 x $10^{33}$ joules**. **Energy withstood by the Earth and consequences** Modelling the earth as 6 x $10^{24}$ kg, this provides 5 x $10^8$ joules/kg. Iron has a vaporization energy of 4.25 x $10^5$ J/mol, and with an atomic weight of about 56, that's about 18 mol/kg. So the energy required to vaporize iron is about 7.6 x $10^6$ J/kg. This is an upper limit, since the core of the earth is a good deal warmer than 20°C. As a result, a rough estimate says that the earth will be vaporized after about 22 hours. Even if ablation shields the unvaporized portions of the planet by 98%, the earth is completely vaporized after 46 days. It's tough to recover from that. **Case of outer planets** Now, about Jupiter. Jupiter's orbit is a bit over 5 AU. Its diameter is about 10 times earth and its mass is about 318 times earth. So the energy power intercepted by it will be roughly $10^2$/$5^2$, or 4 times as great as earth. It has 318 times the mass, but it's all hydrogen, and I'm not sure of the energy required to blow it apart. As a guess, let's use the gravitational binding energy. For the 4 gas giants, the binding energies are (from "[Gravitational Potential Energy of the Major Planets](http://link.springer.com/article/10.1007/BF00644895)", Bursa & Hovorkova): Jupiter - 2.6 x $10^{36}$ J Saturn - 3.6 x $10^{35}$ J Uranus - 1.6 x $10^{34}$ J Neptune - 2.2 x $10^{34}$ J The total energy received for each planet will be (approximately) Jupiter - 1.2 x $10^{34}$ J Saturn - 2.5 x $10^{33}$ J Uranus - 1.2 x $10^{32}$ J Neptune - 5 x $10^{31}$ J In all cases the binding energy of the planet is at least 2 orders of magnitude greater than the received energy, so by this measure they ought to survive, although the inner ones, especially Jupiter, should expect to lose significant mass. By contrast, the binding energy of Earth is 2.5 x $10^{32}$ J, rather less than the 3 x $10^{33}$ J of energy it will receive, so it should expect to be destroyed in about 6 days, which seems to be in pretty good agreement with the vaporization argument. **Conclusion** So basically, a rough estimate says that the inner planets get vaporized, while the outer planets ought to survive. [Answer] # No Wikipedia has an entry on [Pulsar Planets](https://en.wikipedia.org/wiki/Pulsar_planet#History). This entry indicates that only ***four*** confirmed pulsar planets have been found and a fifth is a candidate. These planets seemed to have formed from three different mechanisms. These planet formation mechanisms are: ## [PSR\_B1257+12's Planets](https://en.wikipedia.org/wiki/PSR_B1257%2B12#Planets) Condensed from supernova debris > > The planets are believed to be the result of a second round of > planetary system formation[4] resulting from unusual supernova > remnants or a quark-nova. > > > ## [PSR B1620-26 b](https://en.wikipedia.org/wiki/PSR_B1620-26_b#Evolutionary_history) Captured after supernova > > At some point during the 10 billion years, the neutron star is thought > to have encountered and captured the host star of the planet into a > tight orbit, probably losing a previous companion star in the process. > About half a billion years ago, the newly captured star began to > expand into a red giant > > > ## [PSR J1719-1438 b](http://www.swinburne.edu.au/chancellery/mediacentre/resources/Diamond-planet-Science.pdf) Core remnant left by a "cooked" companion white dwarf > > We show that it is in a binary system with an orbital period of 2.2 h. > Its companion’s mass is near that of Jupiter, but its minimum density > of 23 g cm−3 suggests that it may be an ultra-low mass carbon white > dwarf. **This system may thus have once been an Ultra Compact Low-Mass > X-ray Binary, where the companion narrowly avoided complete > destruction.** > > > (emphasis mine) If a star barely survived a supernova explosion then no planet would be able to withstand that blast *(unless it was sufficiently far away)*. [Answer] Nearly all known exoplanets, including pulsar planets, are quite close to their primaries with correspondingly short orbital periods, since we need several orbits worth of data to detect them. But for this question we want to go to the other extreme and consider planets as far away from their primary as possible, about which we don’t know very much since we’ve only detected a handful by direct optical imaging. It’s perfectly possible and indeed likely that a type II supernova will have gas giant planets at a distance of half a light year or more, and they will easily survive the supernova, but there’s no way we could detect them without millennia of data. We couldn’t even detect a gas giant planet of our own sun at that distance, and one or more may well exist. [Answer] I might note the planets orbiting the remnants of a supernova explosion ("pulsar planets") are sometimes thought to be "new" planets formed by condensing the materials vaporized by the initial supernova explosion. Given the amount of energy being received by the outer gas and ice giant planets during the supernova explosion, I would expect that even far off Neptune analogues are reduced to the exposed core, with the atmosphere stripped away. Since the cores are thought to be about Earth sized, there is some land for enterprising developers, although since the "sun" is a neutron star, things might be a bit cold and dark. ]

[Question] [ [This question about eating on a alien world](https://worldbuilding.stackexchange.com/questions/151775/how-to-check-what-is-edible-on-an-alien-world/) got me thinking.... Would it be easier for humans to colonise a world with existing life, or one which was biologically dead? For the living world, let us assume a world with no technically proficient lifeforms, but one in which living material (i.e. forms of matter capable of using available energy sources to grow and reproduce) is abundant. For the dead world, let us assume a 'goldilocks zone' world with an active hydrosphere (or at least sufficient water to create one given enough heat) and a G comfortable for humans. On the one hand, the living world seems like the best choice, colonisation might be analogous to human groups moving into a new, unpopulated (by humans) environment on Earth in which the colonists learn to make use of the natural resources available. On the other hand, some of the answers to the linked question suggest that we wouldn't even be able to produce food on the new world as there is no reason to think that the alien biochemistry would be usable in any way by Earth-evolved life. In this case, the colonists would have to basically eradicate any existing life-forms and replace them entirely with Earth stock. This strikes me as a harder task than just starting from scratch on a suitable rock. So, should future space colonists be aiming for that exciting distant world with the traces of life detected by atmospheric spectroscopy, or should they set course for the god-forsaken rock with nothing but the cold, lonely isolation of space for company? [Answer] Future space *colonists* should aim for the lifeless rock. Problem with alien biochemistries is that they *might* be immediately hazardous (anaphylactic shock after a lungful of the local air) or *maybe* its just filled with stuff that causes horrible birth defects and chronic brain damage and your brave new world is going to turn into a hideous and drawn-out deathtrap at some point in the next few decades. It'll take you so long to work it out, one way or another, that you'll have to set up camp on the next nearest lifeless ball of rock (or build a nice orbital habitat) anyway, so you may as well make yourself at home there. (also, a world with an active hydrosphere and an earth-like gravity sounds positively welcoming compared to the lifeless rocks in our own solar system. definitely not a place to complain about!) More generally though, earth-like planets appear to be unusual, to say the least. Although we won't know until we manage a better way of surveying exoplanets, it also seems likely that *life* is pretty rare, too. Finding a world that would be hospitable for terrestrial life *and* has its own autochthons already? That's a pretty amazing find and one worthy of an awful lot of study. Wrecking it by contaminating it with your filthy microbiome greatly reduces its value and puts it at risk (because we might be the ones from the horrible all-consuming deathworld ecosystem) so it should be left pristine. That won't go down well with a certain kind of colonialist mindset, but you can always play them some videos of other manifest-destiny types dying of horrible xenobotanical allergies and hope it gives them pause for thought. --- *addendum* Breeding rats and monkeys and exposing them to the xenobiome *might* help prove safety, but rats and monkeys ain't human, as people reading (and doing) science [often need reminding](https://twitter.com/justsaysinmice?lang=en). Until you've had a statistically relevant number of people produce and raise a statistically relevant number of children to adulthood (and ideally to the point where they start their own families) *you can't be sure you brain and fun bits won't melt horribly next week*. Just stay away from the alien replicators, especially if they evolved to live in environments a bit like *you*. [Answer] Unfortunately, I suspect the best choice is # Start with a living world, then kill it The dead worlds are unlikely to have water and breathable atmosphere. The living worlds have, well, life — at its worst, deadly on contact, at its best, kudzu and mosquitoes and funguses that eat rubber seals. But if you can hit the planet with neutron bombs, you can kill off even microbial life but leave the atmosphere and water usable almost immediately. <https://en.wikipedia.org/wiki/Neutron_bomb> [Answer] You will have to make **assumptions** about the likelihood and severity of problems. * The best case would be a highly compatible biochemistry. You can assume that the choice of [amino acids](https://en.wikipedia.org/wiki/Amino_acid) and the [chirality](https://en.wikipedia.org/wiki/Chirality_(chemistry)) of organic molecules in terrestrial life is **not random**, but rather a subtly optimal combination. * The worst case would be an incompatible biochemistry. Starfish Prime explained that in this answer. * A lifeless rock falls somewhere in between. You will also have to make assumptions how likely a world with the right gravity, temperature, etc. is going to develop life. If life comes up easily, then any suitable world will have a biosphere. There must be **something wrong** with the lifeless world -- too small, to big, too little atmosphere, too atmosphere ... [Answer] Given the random element driving evolution and the multiplicity of possible chemical out comes it must be highly unlikely that an alien biosphere would be hospitable to life from Earth. There is every possibility that different bases, sugars, amino acids and many other novel unfamiliar compounds would have evolved. Some probably harmless, some less so and some toxic. Life would adapt to its environment so the locals would be well adapted to live in their alien biosphere and would be difficult to eradicate. Earth based plants would be out competed and probably poisoned. So to answer the question, best to find a barren planet with suitable materials rather than an alien biosphere. [Answer] It would be much easier to colonise a living world. Non-living worlds do not contain much oxygen or products of a long chain and a long time mulching through various substances. Living worlds mostly got that covered, although different products might be toxic cross-ecosystem. So. 1. Scan for biocompatibility and toxins, 2. Prepare substances to bind/remove the toxins, 3. Sterilize the living planet, 4. Reseed with your own bio system, 5. ??? (probably do some gardening) 6. Profit! (name the planet Eden or something and rent the space to the rich space people :D) [Answer] # How Goldilocks? If a planet lay in the Goldilocks zone but doesn't support life, why is that? Lack of water? No magnetosphere? Too many asteroid impacts? Metal poor? If life isn't there already, the conditions may make it hostile to permanent settlement. If life *is* present, then at least *something* was able to adapt to the conditions. If you have significant amounts of liquid water, good partial pressure of O2, a water cycle and a functioning magnetosphere, then you're already a pretty big leg up on all the other planets we currently know about. That's a heck of a lot of terraforming already done for you, possibly some or much of it due to your new organic friends. # Strange Biology We don't know what life could look like elsewhere in the universe. But we do know a few things: the laws of chemistry and thermodynamics appear to hold for other solar systems, to the extent that we can infer them (from spectroscopy, redshift, etc.). Since life is an information-dense chemical system, we know that it requires fairly sophisticated molecules to achieve its effects. While simple crystals "grow", they don't do so in the kind of entropy-lowering way that cells do. That means it will need molecules that can become large and differentiated. Carbon is a flexible molecule because of its +/-4 oxidation state. Silicon is in the same group, and should have roughly the same flexibility. But the difference in atomic weight causes the chemistry to [differ significantly](https://www.scientificamerican.com/article/could-silicon-be-the-basi/). So while we can make silicon polymers, we don't know how to make silicon amino acids/enzymes, and have reasons to believe that silicon is not capable of supporting these more elaborate molecules. Of course, the rest of the Group 14 elements (Germanium, Tin, Lead) are hopelessly useless for biology. # Ok, Carbon So if we have convinced ourselves that life is actually pretty likely to be carbon-based, why should we assume that it's anywhere compatible with Terran biology? Well, for starters, it turns out that our genetic code is [highly optimized](https://www.quantamagazine.org/is-a-bigger-genetic-code-better-get-ready-to-find-out-20180102/), from an information-theoretical perspective. So while you could have an equivalent code with a different assignment of codons to amino acids, the 3-base codons, 4 base DNA/RNA code appears to be at least a local optimum. For this reason, other biological systems are likely to have at least a similar configuration. Of course, the chirality choice appears to be free, so you could get unlucky and run into life with incompatible chirality. But we know that amino acids can be created spontaneously under adequate conditions, and thus seem likely to form a good building block on other planets. We have detected amino acids in [space](https://www.newscientist.com/article/dn17628-found-first-amino-acid-on-a-comet/). Yet another reason to believe that exobiology is likely to not only be carbon-based, but amino acid-based. RNA and DNA are not a terribly big step up from amino acids themselves, so they represent one of the simplest viable molecular information encodings. So if the exobiology produces a similar/compatible set of amino acids, then it is *possible* that your colonists can *eat them*. After all, digestive enzymes can't and don't target particular proteins and peptides, but rather just particular [amino acid bond types](https://en.wikipedia.org/wiki/Pepsin). If earth animals can also eat the local flora and fauna, then the colonists should be able to eat a mix of both local- and xeno-food. Terran plants will likely not be able to participate in the local symbiotic networks, and may compete unfavorably with the local flora. But if the other conditions are suitable (light, water, temp), then the colonists should be able to grow Terran plants in isolated greenhouses. # Conclusion We like to hedge our bets and cover our bases and assume that life can take on some mysterious form that we cannot even imagine. But the reality is that chemistry and thermodynamics significantly restrict the kinds of magic that any plausible xenobiology could employ. I am willing to go out on a limb and claim that if life exists elsewhere, there is more than 50% chance it is carbon based, and that if it is carbon-based, there is more than 90% chance it uses amino acids, and that if it uses amino acids, that there is more than 90% chance that it uses some to many of the same amino acids that we do. Note that there is some tolerance in amino acid utilization. If a protein calls for one amino acid in a particular location, but ends up with a different but similar one instead, it can still be mostly functional. Obviously, this is not accidental. When we say that the Terran genetic code is universal and "optimal", we mean that it is maximally robust to the most frequent kinds of noise/errors in transcription because similar codons are assigned to the same amino acid, and codons for different amino acids that are likely to be mistaken for one another code for functionally similar amino acids. Thus, even if xenobiology uses a different but overlapping amino acid set, there is a possibility that some of the proteins used by xeno-life is still partially compatible with Terran life. Writers often cast biology as a binary compatible or incompatible, but the scale is much fuzzier than that. Even on earth, members of different species are *supposed* to be infertile together, and yet we have regular inter-species hybrids like mules and ligers. Such hybrids are not infinitely far-fetched between Terran and xeno-species, though the success rate is likely proportional to how large/complex the individuals are (and thus, most likely limited to unicellular/bacterial colonies). [Answer] A living world is strictly better. But you will still need to live in airtight habitats. You have an atmosphere that has a reasonable pressure. This means your dome doesn't need to be all that strong; you're not trying to keep the dome from collapsing or popping. You probably have a reasonable temperature, so your habitat will likely be easy to heat and cool. The atmosphere protects your habitat from space threats; cosmic radiation, solar storms, and micrometeorites specifically. You're still at risk from big asteroids, but considering this planet has life, the solar system is probably well past its [late heavy bombardment](https://en.wikipedia.org/wiki/Late_Heavy_Bombardment). Since the world has an atmosphere, it must have a magnetosphere. So your orbital infrastructure can use [electrodynamic tethers](https://en.wikipedia.org/wiki/Electrodynamic_tether) for stationkeeping, which is really convenient. Since the world has an atmosphere, it also alleviates some of the dust problems Apollo astronauts had. Lunar dust is jagged and sharp, which makes it extremely irritating to the eyes, nose, and throat, and it's extremely difficult to clean up. It's jagged because, without an atmosphere, there is essentially no weathering. Each grain of dust is the same as it was when it was first chipped off its parent rock. Your alien world doesn't have that problem, thanks to the atmosphere. The world also probably has oxygen and water, so you can use that instead of carefully recycling your own forever. But even given all these advantages, Larry Niven was right. Rotating orbital habitats are better yet. [Answer] If we have biological humans traveling between stars, we are a K2+ civilization, and are capable of disassembling solar systems. If we have star wisps, we are K1+, and we'll arrive and have to build a functioning industrial economy from a tiny object in order to get to the point of being able to "print" biological humans. Current Human industrial civilization exists as a parasite on the Earth's biosphere, but by the time we are launching star wisps we'll have substantial off-world industry (which presumably mostly bootstrapped). It is plausible that the star wisp will want to bootstrap in an asteroid belt during one phase of development, then lower itself down to a living biosphere in order to exist as a parasite on that while it continues to grow. Odds are that biospheres on alien planets won't be compatible with human life, so any printed humans will have to exist within a constructed biosphere. If we want humans to live on the planet, we'll have to terraform the planet, which is a K1+ civilization effort; so you'll have billions of humans living in space habitats long before they are walking around on a world. They might choose to defer printing biological humans until the planet is terraformed; after the 100s or 1000s or 10000s of years of terraforming effort, a human-compatible biosphere is complete, and some printed humans step out onto a green field with a blue sky above. Little if anything will be left of the original biosphere. ]

[Question] [ Anything can be used as a weapon if need be: A person in my story uses a big steel thermos in a fight. How could she beef up the thermos to keep using it as a weapon. [Answer] Fill it with ice cream. That will make it heavier. Also when you are done fighting you can eat the ice cream, and you will probably feel like ice cream about then. [Answer] A real life story. Back in a high school, my friends and I were very much into science, experimenting with a lot of different things. Once on a winter morning, my friend and I procured about one liter of liquid nitrogen, which my friend poured in his thermos and carefully put in a gym-type bag. We happily walked home on a snow packed sidewalk, until I, as it happens, slipped and fell. Unfortunately, my leg kicked my friend's bag in the process, and that's wasn't even a hard kick. However, the bag quickly came alive with an angry hiss. Feeling that this hissing does not portend anything good, my friend put the bag on the snow and backed away from it. I could only watch what was happening while laying down. About two seconds after the unfortunate kick, the bag exploded. Curiously, the bag appeared mostly intact after the explosion, however, it was pierced by countless tiny shards of glass which peppered the packed snow around us in a shiny circle. Neither me nor my friend got any injuries - I credit it to heavy winter clothes that we were wearing. Inside the bag, plastic thermos was shattered to pieces, and the inner mirrored glass vessel had become the shrapnel which shot through the bag's fabric. My friend and I were quite amazed about the explosion - after all, creating a big explosion in which no one gets hurt is one of the top things on the mind of a school student. Nitrogen is a pretty safe substance. There are many things which are relatively safe at cold temperatures (like oxygen or nitroglycerin) but create a lot of trouble when quickly heated. Contact with the snow heated the liquid nitrogen enough that it quickly turned to gas, which subsequently expanded with enough pressure and velocity so as to be mildly explosive, resulting in a shattered glass inner vessel, which became shrapnel-like. Because the liquid-to-gas expansion ratio of nitrogen is 1:694 at 20 °C (68 °F), a tremendous amount of force can be generated if liquid nitrogen is rapidly vaporized in an enclosed space. [Answer] A strap. What you want to make is a **meteor hammer**. [](https://i.stack.imgur.com/9HRuE.jpg) If all you've got is a Thermos and a zombie problem, you need more force and more range. The meteor hammer is a classical Chinese *chain whip* designed to smash archers and infantry hiding behind personal or rolling shields. Specifically, you want the variant known as a *single-headed meteor hammer*. That sound cool enough to you? Let's begin. Basic physics: Force is equal to mass times acceleration (F=ma). Velocity is the result of acceleration over time, relative to a reference point. When you hit someone with an object, *they* accelerate. If they were indestructible (a perfect, inelastic, "rigid body" in physics), and caught an incoming projectile, the combined target-projectile system would have a velocity that is the result of the projectile decelerating as the person accelerates, until the person-projectile system reaches a common velocity. If they did not catch the projectile, some of that energy would remain with the projectile as it deflected (velocity vector changed), ricocheted (velocity vector changed, and reduced as some energy is converted into rotational energy and deformation), or pierced the target (losing energy to friction, deformation, etc). But past a certain amount of acceleration, especially when a small contact area means you have a large acceleration gradient, bone and tissue simply fail, and when that happens, you get massive damage. So, if you have an object of limited mass, and your combatant can only produce a limited amount of force per unit time, what you really want to do is use that force to continuously accelerate something, so that you can build up a larger amount of energy for an attack than a simple punch can deliver. This is the logic for using a flail, whip, or morning star as a weapon. Now, light whips are actually a little more involved; properly used, the tip on a long whip can exceed the speed of sound ("cracking" a whip), allowing a rawhide whip to cut fabrics, or a metal-tipped whip to chip and shatter brittle swords. Provided your fighter can find appropriate rope, chain, steel cable-- or, an interesting Chinese variant, ring-joined steel bars or plates-- in a good length, this is an excellent option. Your clothes and/or environment should be able to provide *something*. Consider using a belt, braided shoelaces, braided cloth strips, animal hide, etc. The size and weight of the mass on the end of a classical meteor hammer is not too far off from your thermos. Still, the thermos is pretty heavy. This is a weapon that will take significant strength and practice to use masterfully, but should be manageable early on. In particular, the user can take up most of the slack for close combat (usually by wrapping the cable around the forearm), yielding a weapon more like a *flail*, which is still quite effective. Here is a video of some of the moves available with this weapon: <https://www.youtube.com/watch?v=bUgzL0tJGrQ> The weapon's effectiveness, intimidation, and danger to the user all derive from the same thing: its unpredictability. When swung in a circle, or when wrapping around a weapon or attacker, its motion is easy to understand. But when snapped (pulled back at the moment the cable becomes taught) or bound (interrupting a wide swing with the hand or forearm), timing is critical. Likewise, note that many of the advanced techniques involve moving the chain around more than one pivot at once. This starts to look a lot more like a *double-pendulum*, a simple system with notoriously hard to predict motion, whose distal movements are extremely sensitive to small variations in control. The major technique classes are: Grapples - the weapon is swung around a limb or weapon, converting the angular momentum of the swing into rapidly-increasing angular momentum around the target. Because the radius decreases, the speed of the final wrap can be sufficient to crush a hand, ankle, etc. Slams - the weapon starts behind the user, and is hurled in a huge, powerful arc over their head, down onto the target. A devastating sneak attack, but easy for an alert opponent to dodge. Likely also suitable for defeating a locked trunk or floor grate. Swings - Side attacks. Difficult to execute, but excellent for discouraging secondary attackers. Throws - the weapon is thrown, like a rock, shotput, or discus, but can rapidly be retrieved from a safe distance. Whips - in your case, with either end of the weapon, depending on material used for the chain, and what you wind up using for a handle. The timing of this attack is less predictable than a throw, so defending against it requires excellent reflexes. One of its more unusual properties is that it can allow a meaningful defense after getting knocked down on the ground-- that is, from a prone position-- provided the user is not already grappling. See the video above for an example of that. If swung with enough strength and authority, the weapon can be used to "clear its orbit" in the middle of an advancing crowd. In short, it's an unusual, exciting, and dangerous weapon that can be used with either rage or finesse, that an unwilling wielder might very well find themselves gradually mastering out of necessity. Worth a look! [Answer] [](https://i.stack.imgur.com/ovMSF.jpg) As I understand the question, there's a character who uses a thermos as an improvised bludgeoning weapon in a pinch against zombies, and continues to use the weapon after that, as their weapon of choice. This question suggests an off-the-wall but practical low-science universe (a la Douglas Adams or Pratchett); where a rationale just needs to stand up to narrative logic, not necessarily to scrutiny with hard engineering and science. To be narratively believable, I think bludgeoning weapons need a few basic elements: practicality, integrity, mass, balance, and reach. **Practicality** Assuming the character places a British level of importance on the role a nice hot cup of tea in survival, and has a generally non-combat role in the party (healer, grannie, wise woman, etc), they'll always have a thermos and kettle to hand, as well as some tea. And a teaspoon, obviously. Of these things, the thermos is the only one that can immediately be used as a weapon, so kinda makes sense in character, in extremis. **Physical Integrity.** You can't beat someone up with a rotten stick. While the glass-lined, plastic thermos of yesteryear was a useless beast even for such purposes as "holding warm tea" without lacerating the drinker's innards with shards of glass, the more modern but still humble metal-lined thermos can take one heck of a beating. **Mass** Even empty, a double-lined metal thermos has decent heft, and a good edge on the base. Full, you're adding a good chunk to its weight. Assuming the above 2l model, you can add 2kg of liquid, or about 4kg if you add sand in with the water (wet sand has a mass of a little over 1.9kg/liter). Few who've carried even a 1 litre thermos, like anyone who's carried a 6-cell maglight, will have much doubt about its ability to cause blunt trauma. **Balance** Here it starts to have problems. The grip's all wrong. The handle's on the side. The whacking end is likely going to be the bottom, but there's nothing on the cap to hold it by - it'd just be knocked out of any hand that tried to hold it. So, at the very least, it needs a handle. **Reach** And here, too, it falls down. It has no more reach than smacking someone over the head with a flowerpot, so is likely to be no more use. I think @John's on the right track here, it needs a long handle to resolve both the problem of balance and of reach. His suggestion for telescopically clubifying it may work, though I feel it'd be a hard engineering problem to make that work and still have both a functional thermos, and functional club. Instead, what if the walking-stick of the wielder had a thermos cap on the end, as the handle? Then to weaponize stick plus thermos, simply unscrew the cap off the thermos, screw the walking stick into the top instead, et voila, thermos-club. There's also the possibility that the insides could be filled with something harmful to the undead - holy water, perhaps (which maybe does more damage when heated, in which case, at a pinch, you can also conveniently turn it into tea!) Or scalding water, liquid nitrogen, whatever zombies can be harmed with by sprinkling them lightly with in this universe. In that case, you'd need to use it more like a censer, to sprinkle the holy water at the undead. Poke a few holes in the inner cap, tie a rope to he handle, and you can maybe spin it around your head, sprinkling all around. [Answer] If the "big thermos" is actually a steel canister of exactly the right proportions, you can use it like a gauntlet. Put your hand inside and tighten your fist; the hand is now blocked inside the cylinder, which covers the arm up to the elbow. Some canisters can weigh up to three kilos. While the zombie scratches uselessly at the cylinder, you can swing it quite handily, pardon the pun, and cave its face in. Zombies are no more impact-resistant than normal humans, and three kilos of steel punch can quickly take the fight out of one. Later, you can screw some bolts in the steel and file them to points, and you've built a sort of gauntlet plus spiked mace. Not really recommended for melees though. [Answer] turn it into a collapsable club. Anyone with some mechanical skill and machine shop could manage this. It just needs to expand is several telescopic sections. you could even cannibalize a collapsible baton for parts. There is even a RWBY character that has one of these. [](https://i.stack.imgur.com/84Lfa.png) [](https://i.stack.imgur.com/6rgWu.png) Of course it won't have much in the way of storage capacity after this. but if you give up on it holding liquid you can make a pretty sturdy club. Plus if your hunting zombies a club is one of the better weapons you can have. Alternatively use the thermos to make a silencer, it just won't work for long. [Answer] It could be used to make an ad-hoc time bomb. Fill the flask with liquid butane or propane or a mix of the two and securely seal the cap in place. Put a lit candle on top of it and retire. Eventually as heat seeps into the flask over several hours the butane/propane will heat up and start to evaporate. The pressure will increase and at some point the top will be blown off by the butane/propane gas pressure and will be ignited by the candle causing a fire ball. Alternatively fill with butane and seal. Tie some petrol soaked cloth around light it and (quickly!) drop it from a tall building on to the enemy below if it hits the ground hard enough the cap and or bottle will crack or leak causing an explosion. If these options are not appropriate how about filling it with boiling water. Should remain an effective scolding agent for an hour or more. [Answer] **Acid!** Many thermos are made with a glass vacuum bottle. Glass is inert to many acids and also easy to shatter. Sling that bad boy and your foe will despair as skin melts. [Answer] Weld a metal bar to one end of it. Instant club. [Answer] Dewi Morgan outlines two problems with the thermos: balance and reach. Simple solution: The thermos was in a holder bag. The bag has belts/strips which change the balance and add reach to the improvised weapon. The bag could add to the durability of the thermos, in particular if we are talking about a good quality leather thermos holder. However, also note that the strips of low quality bag might not last much. As per fighting with it, I would expect it to be be similar to using a purse as improvised weapon. Addendum: It is also lowers the control over the weapon. Did the character take some self defense course? Let us say the character took some self defense course. [Answer] how about strap or tied it with rope to ad it into flail (may or may not include the stick) fill it with water,sand, or whatever thing that can be put into it to increase the weight. after all other has mention that it far more practical to just use the stick rather than attaching stick to the thermos. [Answer] A thermos is unwieldy. There is no sure way to grip given the amount of force required of a blunt object, which also leads to the issue of not wanting to both be in close proximity and only have a loosely gripped blunt object. Let's face it, the thermos sucks. It is best suited towards filling with coffee and reflecting on all the success the firearm had. What you would really want to do is *transform* the thermos into, well, not a thermos. Let's make, a **hammer**. 1. Remove the lid 2. Fill the thermos a quarter of the way with dirt 3. Crush the top three quarters into a handle 4. ??? 5. Thor Probably not quite Mjolnir, but it should do quite nicely for prolonged bashing. As an optional conversion from this point, crush the bottom part in a crevice to achieve a nice right angle for a hatchet-ish weapon. [Answer] This one is easy and even I might go for a thermos too (without emotional attachment). Drill two large holes close to the top and pass a chain. Then melt and **lead**, tin, or solder and fill your thermos with it, capturing the chain in the liquid. These metals have relatively low melting temperature, and very very heavy. The thermos she is using should be of extreme quality to withhold the forces but in the end she will get an extremely well crafted **flail**. If you use lead it will weigh 11kg (assuming 1lt) excluding the weight of the thermos itself. 11kg in such a small size that you could swing easily over a meter long chain would hit better than any other club you could come up with. Even if you go with solder, which is extremely easy to find and melt, you will still get 9kg. [Answer] 1. Fill it with coffee. 2. Give it to the nearest zombie to drink. 3. Given the well-known power of coffee to make people "more human", the zombie will come back to life and start fighting on your side. 4. Let the restored zombie fight the other zombies while you make more coffee. [Answer] Stuff the thermos with explosive. Attach a fuse to it. The explosion will fragment the steel case into shrapnel which will throw havoc in the surrounding of the explosion. For additional bonus you can mix the explosive powder with other metal objects. Or boobytrap it, using the lid or the dispenser as trigger for the explosion. When the thirsty enemy will attempt to check/use the thermos, will be blown up. [Answer] **Thermos Spud Gun** Ok, so a level of handwavium is required here. The basic principle behind a potato gun is that it has three parts - an ignition source, a barrel and a combustion chamber. A potato (or suitable projectile) is forced into the barrel, the combustion chamber is filled with a volatile propellant, and the ignition source ignites the propellant, sending the projectile out of the barrel. In your situation, the thermos becomes the combustion chamber. Weld a steel barrel onto the open end of it (\*being a steel thermos, it needs a steel tube). You'll want something that tapers the barrel down to a diameter around the size of a pool ball before having a smooth pipe around a couple of feet long. Then, drill a hole into the rear of the thermos, and screw in a piezo-style oven igniter. You now have a thermos musket. Substitute the potato for a bunch of pool balls as I mentioned above (you may need to wad them with something to create a decent seal down the muzzle), and find some hair spray etc to use as your propellant. There's a lot of additional maths surrounding the optimal diameter/length barrels to match a certain size of combustion chamber, but throw in that handwavium from before and start blasting your zombies in half with cue balls. [Answer] Once I was biking in the cold with a friend, and I put hot chocolate in a thermos. Considering it was only tap water on the highest setting of heat, the thermos did pretty well at maintaining a consumable temperature for the drink. Acknowledging this ability, I would personally add boiling water into the thermos or possibly even molten aluminum or solder depending on the material that the thermos composes of. This could be wrapped in a non-conductive yet heat resistant coating such as glue and saw dust, added with a layer of plastic wrap. Wrap it in ways that will continuously allow the opening and closing of the device so that you may sneak up on your enemies and dump surprisingly hot liquid on them whether its on their head, or tossed from a distance like a bucket of water. [Answer] Fill part of the thermos with liquid cesium at a temperature of, say, 80 C. Then you put a thin plastic lid over it such that there is a small gap between the cesium and the plastic. The part above the plastic is filled with water and you then close the thermos. If you shake the thermos, the plastic separation between the water and the cesium will burst and you'll get an explosive reaction between the water and the cesium. The thermos will burst which will cause a secondary explosion due to hydrogen gas from the reaction escaping into the air and reacting with oxygen. You can improve the design of this weapon by putting multiple alternating layers of water and cesium inside the thermos. You'll then get a far more efficient reaction between the water and the cesium. The reaction will continue for much longer after the flask is breached, yielding a much bigger explosion. [Answer] If she is very clever she can make nitroglycerin out of urine and some other stuff and perhaps it would be thermally stable inside the thermos and used as a huge grenade. Otherwise with urine she can make black powder and find some flint in the garden and mix up flint and black powed which whill explode when it hits something. You can put anything in a thermos: hot oil, chilli powder, boiling chilli sauce, liquid nitrogen, and you can take out the protective plastic shell and have a glass thing which whill explode when it hits something releasing whatever is inside. [Answer] Fill the thermos with a hard vacuum and hurl it toward your enemies. The thermos will collapse under atmospheric pressure creating a loud and disorienting bang. Close enough to your enemies, the implosion can be fatal. Use this moment to flee. Alternatively, you could fill it with a high-pressure fluid and achieve a similar effect. ]

[Question] [ Orgone is the measure of a person's connection with the cosmos. It is the conduit through which the power of the cosmos flows, focused through a sorcerer's will. Ritual practicioners must draw on this reserve of power to make a magic spell work. Spells require a constant infusion of Orgone through rituals. These rituals vary by time, and can last anywhere from 30 minutes to several hours depending on the spell. Due to these parameters, casting can be both physically and mentally taxing on an individual. Most of the stronger spells will require more Orgone than one person can provide. It is possible to make the success of the ritual more likely by investing more power into the spell. This power would come from assisting practicioners, who add their own Orgone to the spell. Most rituals are made up of a primary caster, followed by assisting casters adding to the spell. It stands to reason that a ritual should be quicker due to the influx of power from various people. However, the time frame of a ritual stays the same regardless of how many casters there are. Why would this be the case? [Answer] "If it takes an orchestra with 40 members 60 minutes to complete Beethoven's Ninth, how long will it take an orchestra with 60 members to complete the piece?" Anyone vaguely familiar with how music works in even the most abstract sense should understand how absurd that question sounds, especially to a musician. Perhaps the question of adding more mages to speed up a ritual is equally absurd to a magician? Rituals, like musical pieces, have a set tempo and duration to them. The tempo of the ritual may be altered, but not by adding or removing mages. Instead, additional mages might be added for a different reason altogether. Taking again from musical practice, there is a thing that wind instruments will do called staggered breathing. When there is a particularly long note to be held, or when it is difficult to find a place to breathe without disrupting the rhythm, musicians will stagger when they breathe to make sure they don't breathe at the same time. If done well, the result is that no one hears any of them breathe, and the note and rhythm are never broken. Perhaps your magicians make use of a similar staggered technique, where the additional participants are to ensure that the performance of the ritual is never broken, even if it would otherwise require an astounding and inhuman display of endurance. [Answer] For the same reason nine women can't make a baby in one month. The spells are full of components that simply can't be divided or done in parallel: each step requires a certain amount of time to complete and have to be done in a certain order. Adding more resources can't make the steps go any faster, and more people may even cause it to take longer([which happens often in the world of software](https://en.wikipedia.org/wiki/Brooks%27s_law)). [Answer] For much the same reason that nine pregnant women together are not going to bear a child in one month. The speed of a ritual is **not** proportional to the amount of mana you put in. In cooking terms, mana is an ingredient, not the fire. In more scientific terms, mana is not a form of energy - you don't measure it in joules - but a field, measured in thaums. So adding more people or magic materials to a spell is akin to adding more dough to a pizza. It will feed more people, but it will not cause the pizza to be ready faster; Might even take more time to get it ready. If you want to accelerate a spell, change not the materials, but the setting. Go to a volcano for fire spells, or cast lunar-related spells under a full Moon. [Answer] If a ritual takes 30 minutes then it's going to take 30 minutes if one person does it or a hundred people. If 100 people recite, for example, the Lord's Prayer, they won't recite it any faster than one person. [Answer] More power requires more control of said power. These rituals are already taxing on an individual, adding more people for more power only increases the pool of power available. The primary caster acts like the control unit and may or may not actually contribute power to the spell at this point. There can't be multiple people controlling the spell because they might step on each others toes and create feedback. Therefore, the spell can only be cast at the speed of the person shaping it no matter how much power is required. [Answer] It's like a water hose. There is a maximum volume of water that will flow through the hose, regardless of how large you make the tank it is attached to. In this scenario your primary caster is the end of the hose and the secondary casters are adding water to the tank. [Answer] The above examples are great, and true, but here's an alternative way of thinking of it specifically related to power. You make a device that broadcasts radio, and the device required 1 AA battery to run. A second generation of the device has more features, and requires 2 AA batteries to provide the necessary power (amperage) for the device to operate. It would not, however, play the radio broadcast faster. In fact, if you took the first radio and added a battery, it would still consume the same power, meaning you'd have doubled the reserve of power available (proper wiring permitted, and in an ideal environment), but it would still only perform the function for which it was intended. [Answer] If you need a flame at 300 ºC during an hour to cook a meal, a flame at 9,000 ºC won't cook it in 2 minutes. An increase of heat (or power, mana, etc) doesn't necessarily increase the speed of the process. Conduct a ritual isn't something that can be made in parallel, so it could be divided into small parts for each mage to cast. It's like drawing, several artists (usually) can't work together in the same draw, their creative ideas are just different. Or like doctors, a surgeon can perform an operation in 4 hours, but 20 surgeons won't finish it in 12 minutes, even more, so many people will commit mistakes. Spells and rituals are things that must be made in sequence, you can't just add more mages to divide the work. Each mage must perform a specific part of the ritual, so if a ritual was made to require 4 mages (one to channel the power, another to give it form, other to cast it and a last to supervise everything) you can't use 8 mages, there aren't enough jobs (or "magician slots") to perform, and these works can't be performed by several ritualists at the same time. Even more, maybe magic is like a painting. Paint a wall can require a few hours to let it dry, several painters won't speed up the drying process. Mana or orgone needs time to acquire the shape of the spell, and that time can't speed up... not without suffering risk... [Answer] > > ... the time frame of a ritual stays the same regardless of how many > casters there are. Why would this be the case? > > > Because in any magic system that is studied and applied, there is always the same problem, for the measure of Orgone there is an equal and opposite measure that counteracts that power. Adding more practitioners simply makes the "Shadow Orgone" increase in power in a way that's proportional - and creates forces of chaos thus preventing progress. Since no shared psychic-mind has been succesfully created for the length of time necessary to cast a spell, yet, then only a single mind will be able to steadily work it. Until the lost ***"Legion Spell"*** is found, that enables all minds to act as one. That's why magical practice is essentially a solitary thing - even if it's practitioners are team-players and sociable people. [Answer] The different mages perform different and concurrent parts of the spell, which are all needed together to make the spell effective. Think of it like two pillars and a beam. The beam holds the pillars and the pillars support the beam. They can only work together, having one less will make the whole ensemble useless. [Answer] You answered your own question. There is one **Primary caster** and other subsidiary casters. One caster pulling on too much 'Orgone' can burn themselves out, so they evenly distribute their loads among other secondary casters. However, the primary caster, who initiated the spell, is still the 'conduit' which pumps Orgone into the spell and powers it. The others are just ensuring that he has something to pump. Therefore, the speed of casting will be determined by the power of the primary caster, and not by the number of casters working on the spell: Adding more casters (I'll call the secondary casters gatherers) will only reduce the load on each individual gatherer. [Answer] There's a limit to the flow of Orgone into a spell. A certain amount of Orgone is needed for a given spell to work. Orgone flowing through an individual is taxing work, and can exhaust individual spellcasters. However, working together, multiple spellcasters can divide the flow amongst them [Answer] The Orgone comes from a certain place in the astral plane, and has to travel to the site of the spell. As a physical analogy, consider the spell "bring water". If I am on an island in a lake, a single caster can typically generate a small wave 1 metre tall bringing water from 10 metres out. Multiple casters can generate a wave that engulfs the island bringing water from 500 metres out. This requires more effort and (because the water comes from further out) it also requires more time. It is possible to form a pond of water into a wave and magically cause it to roll over dry land carrying objects on top of it but this requires not only great power but also great skill. There is a legend of a Great One who can actually surf across land on a magical wave of their own creation. Now consider these physical analogies involving water, and imagine that this is how the orgone flows to the site of the spell to be casted. For casting at a distance, the orgone may move directly from its resting place to the site of the spell or alternatively have to gather itself toward the caster then jet out towards the site of the spell. Clearly there will be a finite time for the orgone to travel there. Orgone tends to collect in certain magical places such as caves and tends to evaporate in the city. There is a huge reservoir of it on the moon. Now this leads to a problem: magical power without knowledge, wisdom, and good intent can be a dangerous thing. A powerful but unskilled individual is unlikely to do any damage, but a group of reckless young spellcasters can wreak havoc when they work together to wield powerful magic. They may for example send a tsunami of orgone toward a slowly approaching foe such as an army of trolls, only for it to backfire and engulf a village. For a sufficiently large spell there may even be time after the spell is cast to run and inform the villagers to evacuate before the spell hits. [Answer] Consider: the size of a symphony doesn't increase the speed of the piece. It can, however, make the piece more moving and effective. [Answer] Spells are a creative work. The most difficult and time consuming part of creating a spell is thinking through how it is designed, how it's shape will affect the world. A complex ritual would require the primary caster to think through an enormously complicated problem, like solving a 10x10 rubix cube in your mind. The extra casters can help provide more power, and more energy, but they can't make the spell any simpler. [Answer] Because only the primary caster is actually casting the spell in question. All the assistant casters are casting a different spell: `Supply Orgone to other caster` [Answer] for the same reason that > > adding manpower to a late software project makes it later > > > from [The Mythical Man-Month](https://en.wikipedia.org/wiki/The_Mythical_Man-Month) It's a well know fact that [magic and computer science are very similar](https://en.wikipedia.org/wiki/Structure_and_Interpretation_of_Computer_Programs). From this you can simply replace mention to computer sciences in the overused quotes of The Mythical Man-Moth with spellcasting ones. Here are a few: > > Men and months are interchangeable commodities only when a task can be partitioned among many workers with no communication among them. This is true of reaping wheat or picking cotton; it is not even approximately true of spellcasting. > > > . > > Einstein repeatedly argued that there must be simplified explanations of nature, because God is not capricious or arbitrary. No such faith comforts the mage. > > > . > > I believe that large rituals suffer management problems different in kind from small ones, due to division of labor. I believe the critical need to be the preservation of the conceptual integrity of the product itself. > > > [Answer] Because each mage has a particular magical "frequency" similar to radio waves. When multiple mages attempt the spell their magical "frequencies" cancel each other out. [Answer] Several answers already express what I want to say, I am just trying to give them additional conceptual background (they explain on examples, I will try to formulate a principle). In order for a collectively cast spell to work at all, participants must draw from the same "direction" (not actual physical direction, but in some transcendental sense) of the power source. The more different their "directions of approaching the source" are, the more significantly does the result weaken. As an extreme example - if two mages draw from opposite sides, the result will be just weakening for both, without any positive outcome. Now the nature of this "direction" is such that for several participants to find coinciding direction, they must overcome differences between each other, become less individual and more parts of a whole. The more mages are there to participate, the more difficult is it to achieve this goal. As the number of participants increases, inevitable individual differences that they simply cannot give up without ceasing to be themselves each become more and more apparent, thus reducing the effect of collective efforts. ]

[Question] [ I'm making a story with the standard Tolkien races. Not terribly original, I know, but it makes for good practice fantasy writing. While I was planning out the history, I realized that orcs generally have physical advantages over humans, most commonly in terms of strength or endurance. Considering that humans, dwarves, or other fantasy species don't have any biological traits to counter this, what is it that is keep the orcs at bay? Basically, **if a species has a distinct advantage in combat, what could be used to keep them from bullying the other races into subjugation or extinction?** The only traits I would like for these orcs to have other than the strength are the ability to use tools, the ability to verbally communicate and write, and some means to keep them from being exterminated by other races/species. The last point is so humans don't just retaliate against orcs when they're hibernating in the winter or something. If possible, avoid political factors (they're just crappy leaders!) or involving divine beings (humans have better gods, and the like). Examples of an author successfully integrating any over-powered species would be appreciated, even if it's unrelated to orcs or other species physically superior to human beings. --- *edit- May 13* Wow, I am really amazed at the thoroughness and clarity of the answers I am receiving. There has been a lot of enlightening information, especially about the handling of orcs and goblins in Tolkien's world. That being said, there seems to be a pattern of thinking of orcs as an ethnic group or organization, the Khans of classical Mongolia being the most frequent comparison. This line of thinking assumes that political structures (in this case, tribal societies with tiers based on martial prowess) are inherent to a species' genetic makeup. I'm all for orcs with Spartan or Mongolian social structures, but assuming all orcs would be down for sieging the same castle their last four generations died on would be strange without a reason for it. I understand this is the type of thinking that Tolkien and many other authors subscribed to, and that using species interchangeably with ethnicities is a common practice, but assuming that orcs (or any other species) have static political structures doesn't make sense to me. As an example, if the orcs were incapable of digesting grains or other easily farmable plant matter, they would have a lot of difficulty establishing permanent settlements. They might be individually stronger than humans and (potentially) just as smart, but can't amass in large numbers as easily because of this. [Answer] I'm going to ignore what you've said about Tolkien because Tolkien's Orcs are not the Uruk-hai, Uruks are weird crossbreeds, Orcs are more like modern DnD Goblins with delusions of civilisation. So why would a race modeled more closely on the Uruk-hai have trouble taking or holding a world? Apart from what I've seen here I would suggest that they're boom-bust breeders, so hordes of Orcs periodically spread out from their version of the [Fertile Crescent](https://en.wikipedia.org/wiki/Fertile_Crescent), an area that can and does support a huge dense population of peaceful Orcs on smallhold farms, they take huge swathes of territory but for various reasons can never hold it. Every so often Orcs go into a breeding frenzy, doubling or tripling their numbers in less than a generation, this could be triggered climatically or it could be a simple biological cycle, whatever the cause their homeland suddenly can't support their numbers. Vast numbers of Orcs young and old move out to take up new land, between the natives contesting ownership and the fact that this land is not as fertile as that at home the exodus doesn't get all that far and since their population has to spread out so much more to live on the relatively barren new holdings they're seriously vulnerable to counterattack. This is thought to have happened with some regularity in antiquity with populations on China's [Loess Plateau](https://en.wikipedia.org/wiki/Loess_Plateau) and the [Eurasian Steppe](https://en.wikipedia.org/wiki/Eurasian_Steppe) migrating into Europe and the Southern parts of Asia. [Answer] You say to avoid political factors but realistically it is **ALL** about politics. Specifically Orcs cannot sustain political authority or more precisely loyalty. Orcs are loyal to the most charismatic (or simply powerful) leader present. If the leader is not present they will not follow the leader. This might be due to high level of aggression, short attention span or simply inability to commit to an abstraction such as a state or a king. Any of these would be sufficient and Orcs are generally portrayed with an abundance of all these characteristics. This limits Orcs to tribes where everyone personally knows the boss and one boss replaces another after a fairly short conflict to find out who the boss is or alternately to single goal hordes that follow a single charismatic big boss that the tribes believe can give them victory. Or at least loot and plunder. This means that while a horde will be a huge danger and be able to simply overwhelm most kingdoms, it will rapidly devolve to tribes fighting each other for the spoils, if the big boss dies, Orcs lose trust in him due to a set back, or the horde actually succeeds in its goals. Why go far away to loot and burn a city when you already burned a city and have problems carrying the loot you have? And the the isolated tribes will be easy pickings for any organized force of humans, elves or dwarves. The military force of a tribe consists of the warriors of the tribe showing up with whatever equipment they have and following their leader. Individually they and their equipment might be good but they won't have the discipline or organization to contest a real army with actual logistics and tactics. The classic source for this is probably [the account of the Gallic Wars by Julius Caesar.](https://en.wikipedia.org/wiki/Commentarii_de_Bello_Gallico) The Gauls were fairly civilized and well equipped, their warriors had no shortage of courage, and they often had superior numbers but the war was still heavily stacked against them. The Romans just were better organized and more professional about it. With Orcs the gap would be even larger even if you don't introduce anything resembling the legions to the setting. The Gauls really were fairly sophisticated people. Another good source would be various colonial wars. Especially examples such as Madagascar or New Zealand (and many others) where a charismatic strong leader stopped the colonial powers cold but as soon as the leader died the resistance would fall apart and colonial powers could pretty much walk in. This would happen even with areas with fairly small technology and "civilization" gap such as India. Orcs would be **permanently** handicapped with a larger gap in level of organization and social abstraction. Given how devastating the colonialism was nations of same species with fairly sophisticated civilizations I think this is all you need to explain why Orcs do not rule the world. They probably need individual combat superiority to avoid going extinct. [Answer] Humans/dwarfs/elves have large cities, farms and other aspects of a *civilisation*. Orcs have no such things. The orc-lands to the North are vast but there is no unified nation or supreme leader. The orcs live in small semi-nomadic hunter-gatherer tribes. They war with neighboring orc tribes as much as with nearby human/dwarf/elf cities. As long as our border cities have proper walls and defenses to repel a few dozen troops at a time, the orcs are not much of a problem. This raises the question of why we don't just raise an army and wipe them out. We tried this a hundred years ago but all that happened was the orcs tribes rallied to fight us. It turns out as long as a powerful foe is immediately present the tribes will stop fighting each other and fight us instead. Our army was well trained but couldn't compare with orc *society* where there is simply no such thing as a non-combatant. Our army was destroyed and the resulting Orc WAAAGH! rampaged to the South and destroyed three of our cities before it hit the King's River. Unable to cross, cohesion broke down and with no enemy present most of the orcs died through a combination of starvation (they had no supply trains) and infighting. Orcs are also known as prolific breeders. Twins or triplets are normal for an orc mother and an orc is full-grown by six years old. By the time we had rebuilt our cities the orc-lands had repopulated and gone back to fighting each other as though nothing had happened. [Answer] What if despite all the Tolkienic propaganda, orcs aren't actually jerks. Maybe they've had a few near misses with genocide and decided genocide was wrong. Maybe they learned that when their species subjugated other races, the end result kinda sucked. Fine things ceased to come out of that culture ( "fine things" being, to an orc, tasty food, wagons that actually hold up, quality weapons and armor since the first thing you do in an occupation is outlaw them, etc.) Meanwhile they were forced to waste their time being jailers and fighting a bloody insurgency, in the end wondering who was jailing whom. So they confine their foreign affairs to getting others to "leave us alone". [Answer] Orcs might be famous for their strength, but they are not known for their smartness. They are usually depicted as dumb and short tempered. And a certain Leonidas with his 300 soldiers has shown that brute force alone is useless against a smart and well disciplined opponent. You don't need anything additional to keep control on the orcs: just remove their leader, or provoke them into breaking the battle order. [Answer] Orcs hate sunlight. They much prefer to attack at night, and their cities are mostly underground. When they're defending a well-lit city they're at a huge disadvantage, so they avoid holding such targets unless for larger strategic goals. Better to plunder and go. [Answer] **Your Orcs aren't Tolkienic** Your orcs aren't actually Tolkienic, Tolkien's Orcs were actually more goblin like than the hulking world of Warcraft or D&D style ork we have in the common parlance today. In his written work he details that orcs were about a head shorter than a man and tended to be cringing cowards and sulking malevolent punks when left to their own devices. They were supposed to illustrate that evil cannot create life, only counterfeit a twisted and inferior imitation of creation. The orcs in Tolkien were dangerous because they had numbers and the support of an evil divine being. I would say your orcs are more modern table top gaming variety (aka green barbarians with big teeth). A good Explanation for the orcs in your story don't own the planet is the same reason Alexander the great's or Kublai Khan's empires lasted only as long as their rulers did. They are a fractious and tribal culture who are often more concerned with fighting each-other than conquering outsiders. Whenever a leader powerful enough to unite them does come along they become a true terror to everyone else on the planet, but once their chieftain dies his generals and captains begins fighting each-other instead of the enemy and they collapse back into clusters of warring chiefdom's. Tolkien was also a wee bit racist, (pretty much everyone was at the time unfortunately). It was still taken as a scientific fact that race made one inherently superior or inferior, which is why in his books orcs were short, cowardly, and mean, mostly only fighting when being forced to do so by something they feared more than direct confrontation with the "greater, purer" races. There were quite a few elements of eugenics and racism in Tolkien's written work that ensured the bad guys always lost and the orcs never overran the world in the 1000 year periods in between the times when their dark lord showed up to lead them. [Answer] An Orc with increased strength would realistically suffer from a much shorter endurance and lower fine motor skills as their muscles are closer to apes than humans. If you still want to have orcs with high endurance coupled with strength, you can do at least three things: 1: Technological savvy. Orcs try to rule everything with who's the strongest. Sitting down and tinkering with stuff isn't exactly a trait Orcs respect, and even the few Orcs who do metalworking for the weapons and armor of their brethren are probably getting their butts kicked as they aren't on the battlefield murdering stuff as much. 2: Food. You might be strong and have the endurance, but if you can't produce enough food and have the logistics to maintain your army, you are not going to rule the world. 3: Leadership sucks. Social structure is required to maintain any larger group of sentients. Even pretty sophisticated empires have fallen apart simply because the length of time for messages (and with it any repercussions for not paying enough taxes etc) to come through took too long and whoever was put in charge of a province far from the leadership would just get up one day and say "you know what, it's all mine now". Orcs would have such a low leadership capability and lack of social control that any warband send away from the main force for more than a month loses it's allegiance to the main force and become it's own entity (if the main warband doesn't go "hey we've forgotten what you guys were doing and messenger boy isn't something Orcs really want to do so we aren't sure if we are going to cut you dead or beat you senseless till you agree to follow us") Any Orc "state" would consist of hundreds of smaller villages/warbands that have small wars as often as they band together to try and kick a neighbouring country... Or try to overwhelm some kind of warband they have a squabble with. Only something like an Sauronic Capitol "E" Evil could rule enough Orcs to pose a real threat to the outside world. The only solution for Orcs to be any state-like entity with a standing army, would be to rely on slaves. Slaves to play messengers, do their technology and, potentially, their food. Edit: you can ofcourse make Orcs more socially capable and have them form large enough communities or even kingdoms, as long as you give them enough problems that they'll collapse at a certain size. [Answer] Since you want to avoid political answers lets go to ancient history, and my staple of applying evolutionary theory to every answer I can on this site. Orcs already existed, and us humans beat them (or possibly sexed them up so hard we lost track of who was an human and who was an orc, which still counts as a win in my book!) The 'orcs' I'm referring to are neanderthals. They were stronger, faster, and more robust then humans. They appeared to have every physical advantage over homo sapiens. They also had some tools and possibly language, but the lessons we can learn from them I believe apply even if we assume your humans & orcs have more complex language and tool use then the various homo-x of yesteryear. There are two key reasons for why neanderthals did not out compete humans. **They wanted different land then we wanted.** Neanderthals were evolved for the cold northern climate, able to survive comfortably in harsh climates too cold for humans, in fact modern humans got many of the adaptations that allow us to survive in colder climates today from interbreeding with neanderthals (the Caucasians fair skin, freckles, red hair, and even more insulated layering of skin cells all appear to be connected to genes that can be traced back to neanderthals). However just as homo sapiens were not comfortable in the extreme colds of the north neanderthals were poorly adapted for the warmer climates of the south. It's true a neanderthal would fare better in the southern reaches of homo sapiens territory then a homo sapiens would in the northern reaches of neanderthal territory; but they would still not be well adapted to it. In fact one of the key contributors the extinction of neanderthal was the ending of the ice age and the warming of the northern lands, neanderthals either couldn't survive in the warmer lands or couldn't out compete humans in them; but were get back to that in the next bullet point. This meant that while homo sapiens and neanderthals did share some regions of the world, allowing interbreeding, there was never any threat of one species being able to completely eradicate the other. Both species inhabited parts of the world the other species was not interested in expanding into, and so there was always areas where one species could safely flourish without concern with competing with the other species. In regard of your world, I suggest much the same. Have Orcs adapted for a certain territory that they favor so that some human lands are less tempting to them. In fact I'd likely keep the very distinction neanderthals have and have orcs more comfortable in colder northern climates; it makes sense biologically and evolutionary for the sturdier species to be evolved for harsher winter climate. Plus evolution for colder climates would fit for a species that hibernates as you implied your Orcs do. By making Humans have lands that the orcs consider too warm (or wet, or bright or whatever is counter to their evolutionary niche) you give humans a safe spot to grow and spread that ensure they will never be fully destroyed by orcs even if the orcs could win evolutionary Of course this implies Orcs could defeat your humans. It may be they couldn't, as neanderthals ultimately proved unable to out-compete humans. And that was because... **Neanderthals ate too much.** It turns out that the big, sturdy frames of neanderthals, that you would think would give them an advantage over humans, was ultimately their downfall. You can't get anything for free, if you want more strength or a bigger, sturdier, frame you need to pay for it somehow, and in this case neanderthals payed for it in calories. They had a higher caloric intake needed to support all those adaptations. This is a problem because it meant they needed to find more food, more animals to be exact as neanderthals seemed more evolved towards eating meat as their primary calorie source then homo sapiens' more omnivorous diet (which makes sense, meat is a more condensed source of calories which is important if your trying to get as many calories as possible in a day). Ultimately as temperature's warmed up and Neanderthal's lost their home field advantage in colder climates their real downside was that they couldn't manage to keep up with the higher calorie requirements and effectively the species as a whole starved to death (this is actually an extreme over simplification, another key limit was that they were reliant on meat and thus couldn't adapt to eat increased appearance of vegetation for instance, but oh well). For your Orcs you can do the same, or something similar. I don't necessarily suggest having their key limit being needing too much food, as that's a more abstract concept that isn't as easy to communicate the limits of to an audience. But the concept of 'you have to pay for your higher strength somehow' still applies. A species with larger frames and stronger build will also tend towards: 1. slower growth and maturity 2. fewer children born, and longer length of time rearing children 3. (potentially) shorter lifespans Any of these three reasons can be applied to why humans can keep up militarily with Orcs. Effectively in a battle an Orc soldier may be able to best the average human, but it doesn't matter if the humans can field 1.5 times as many solders as the Orcs can. From a biological standpoint there is a pretty linear trade off of strength to population in species, so it makes sense that even if humans outnumbered Orcs generally the military strength each species could compete would be roughly equal if we assume they had roughly the same infrastructure/territory. Put another way, X calories worth of food can produce so much fighting strength, rather you dedicate those calories to producing more, weaker, fighting units (humans) or fewer stronger units (Orcs) the same number of calories worth of food is going to support about the same total fighting strength, with a slight favoring towards the humans approach of numbers. That's an extreme over generalization, but the point is that neither strategy has a drastic advantage or would guarantee one species a clear victory in conflict over the other. Of course conflict isn't limited to war. Conflict can be technological and cultural as well, I'm not going to focus too much on technology, I assume from your question that your intent is to have Orcs intellectually the equal to humans, obviously if they weren't that would be an obvious advantage for humans. I'm not going to even try to make claims over rather homo sapiens or neanderthals were 'smarter'. But culturally homo sapiens may have had an advantage.. **Homo Sapiens worked better in a group** Actually before I go any further let me say this is not exactly an indisputable truth, evidence isn't as clear when certain adaptations were made etc. But I'm including this anyways to make my point, it's my answer I can do what I want :P Neanderthals lived in very small family units, like a pack of wolves pretty much. But comparison it seems humans were (probably?) already moving on to larger 'tribes', much like the packs that chimpanzees and bonobo's lived in. These 'tribes' were still effective familiar units, but larger groupings, think of it as the difference between living with your immediate family and living with your extended family including all your cousins, aunts, and uncles. This is relevant because humans are very well adapted to working in groups. We survive better with pack behavior, and our adaptions that allow us to survive in large groups, and work together as a group to achieve things individuals could not, may very well have given us an advantage in competition over Neanderthals smaller family units. Likewise if Orcs were more divided culturally, or even evolutionary, into smaller family units or tribes they may not be able to achieve what a large organized human goverment could achieve. Of course all this assumes that there is competition. In truth... **Humans didn't fight or kill off Neanderthals** Despite what some like to say Humans didn't 'defeat' neanderthals, they out lasted them. Climate change was the biggest killer of neanderthals. Humans indirectly competed to some degree, in that every resource consumed by humans was one not available to neanderthals, but the common depiction of humans fighting with, out thinking, and dominating neanderthals because humans were just magically better is not how it happened. Neanderthals and humans lived parallel lives, but they didn't always fight. They got along well for numerous interbreeding episodes to happen, for example. Likely the two sets interacted the way any tribe would, defending their home but just as willing to trade and cooperate as to fight. likewise there is no need for Orcs to try to take over the world. Look at any nation in the modern world, The borders of Mexico, US, Canada, etc have stayed stable for some time, Most of the time nations accept territory of other nations and trade and negotiate with them instead of going to war. Yes war's and exploration *also* happens, but my point is that it's not the only option. Part of the reason that one species hasn't wiped out the other is because, on average, neither species sees it worth the fight and so trades and tolerates with the alternate species. They may not like that the species is there, but eradicating them is just too much effort... [Answer] Orcs don't know how to farm. And they don't want to know how. They actually win if they want too, but if they kill everyone then who will produce the food for the next raiding? Humans don't survive under orc care. So orcs just let them be and take what they want later. There could eventually even be a practice where humans just pay tribute to the orcs each season for... "safety", and maybe the orcs just go and cull the cattle humans a bit every now and then when they start eating more food than acceptable. Who would think the soft weaklings would eventually develop ways to fight back? Certainly no orc. [Answer] **Orcs are not good sailors!** ...so as a powerful force, they are limited to their own country / continent. OK, sometimes they make it across the sea / large rivers, but only in small numbers. Any time they've attempted overseas conquest, they have not been able to muster enough warriors to pose a threat, or else most of their ships have sunk / gotten lost or they've landed but very sea-sick. As such - being a powerful unified force (which they must be if they would pose a threat to take over the world), they recognise that overseas trade is far more beneficial than conquest. [Answer] Depends on your flavor of Orcs.If you go completely Tolkienesque, then those weaknesses are already built in (as others have pointed out), but I can tell from the way you've framed the question that you mean more modern D&D type orcs or Warcraftish ones. The answer is simply this: **build your Orcs with whatever flavor you like, with weaknesses built into your species**. If you don't want your answer to be societal or political, give them a biological weakness or two that answers this. Here are my suggestions. * **The race is short lived.** This a biologic answer that ties directly into societal structure and politics. Say an orc only lives 10 years. This will have an impact in several ways. First, any deal orc leadership makes with longer-lived races will be suspect because treaties and such don't last by the reckoning of those races. So humans and others will think that it's better to wipe them out than negotiate. Second, it's harder to pass down information and education if you are short-lived, so they might be less advanced as a consequence. (Or more advanced if you give them the ability to learn more in a shorter period). * **Orcs don't have many children, so others outbreed them.** Just a matter of numbers in this case. There's fewer of them so they can't conquer. As to how this happened--either it's natural or it's engineered. Think the [genophage vs. the Krogan in Mass Effect](http://masseffect.wikia.com/wiki/Genophage). In that case, when the races of Mass Effect were getting overrun by the combat-superior Krogan, a genetic plague was introduced to make females less able to carry children to term. In a fantasy setting, this would likely be a magical curse or magically engineered (rather than science engineered) plague specific to the race. * **An advantage in combat means more combat and less cooperation.** If your Orcs are stronger and better at fighting, it's likely because there's a biologic advantage to fighting WITHIN their own species, or if not, they come from an area where responding quickly and efficiently with violence is advantageous. What you'll have then, is a society of people who are quick to solve problems with violence rather than cooperation. This may be biologic in nature, as pointed out by @John Hamilton, and what that will mean is that they will likely also be killing each other when they don't have anything else to do, leading to instability within their society, and lowering their numbers. Solving problems by working cooperatively is a different biologic advantage, and one that humans excel at. Orcs can be good at 1-on-1 combat, but terrible at listening to each other and working together for any longer than is absolutely necessary. So while they might conquer an area, once there is peace, they either keep moving and conquering (leaving those lands behind) or, to be blunt, they'll start killing each other to prove their prowess, quickly breaking up into factions, and eventually it will be every orc for himself. * **Specialists Limited in Geographic Area** These are your Orcs, and you can build them anyway you darn well please, and this suggestion is one that limits them because of something that they need in a specific area, barring a positive mutation. Kolas only eat eucalyptus, pandas mostly eat bamboo. There can be a specific protein or type of food that's abundantly available in a specific area which they can't get too much of anywhere else. Perhaps they can only live with a certain amount of sunlight (they are allergic) so they stick to places with less, OR alternately more, because they happen to get some energy from the sun. Or they are not cold hearty, and so are limited to places that don't have much of a winter. Or they only like the cold, and completely shut down and die outside the ice fjords or something. These are just a few examples but this limitation can literally tied to any geographic condition--food source or dietary restriction, pollen allergen which can kill them, temperature preference, minerals present in their water--pretty much anything. And you don't even have to explain it in your book if it's something like a mineral present in the water of an area, they might not even have the tech to know, and they might do something traditionally like put the rocks from home in their water skeins on a raid, which helps them for a time, but not in a few generations, if they stay in an area. * **Disease** They catch stuff from other races and are weakened and die from it. They know enough not to occupy elven/human/dwarven cities because of it, but fiercely protect their own territories. * **Surprise! They already conquered everything.** Yep. They took all of it. Temporarily. But for whatever reason, they either died out (biologic) or went home. The going home would be likely political or societal in nature for the most part. Maybe, having done it, they had nothing left to prove and just went home, or they evolved a bit--if they have a shorter life-span they can change more quickly in a shorter span of time. It's possible that after being invaded, they just went out, conquered everything, said "Remember this and don't bother us ever, ever again." and then they just went home, where their closed society now has the finest art, music, and technology. [Answer] Let's go about it this way: The increased muscle mass comes from the orcs having increased testosterone. The inherent ability to fight better at close combat comes from having more adrenaline in their system. This means they have much more of the most aggressive hormones present in their bodies compared to humans. All of this aggression leads to a desire for fighting and killing, it could certainly be called bloodlust. This bloodlust can only be satiated when the orcs have had a good fight. When they don't, they start arguing for any simple thing and they start infighting. This is why the leaders can't just raise an army for a while and then go to war, they just *have to* go to war or watch the army they raised tear each other apart. I think your orcs would best be defined by the [orcs in Warhammer universe](http://warhammerfantasy.wikia.com/wiki/Orc). I also suggest reading through the [WAAAGH! section in WH40K wiki](http://warhammer40k.wikia.com/wiki/WAAAGH!), although that's in space, it's the same basic principle as the Warhammer fantasy universe. [Answer] Additionally to all the social, political and cultural reasons, you can add biological ones, too. I know that Tolkien's orcs and other species did not evolve, they were created, but they could still have different nutritional and biological requirements for life. Orcs and humans (and the other species) fill different ecological niches. For example, in places where the soil contains too much of a certain chemical which is poisonous for humans (take any heavy metal as example), Orcs not only survive but their bodies need this chemical and without it, they die. So sure, they can start wars and encroach on human-inhabited lands but can't stay alive for long because the food they can grow or hunt does not contain a chemical necessary for them to live, or in a not high enough quantity. A bit like that humans can survive long voyages over the sea but their health will suffer if they don't take a source of vitamin C with them. [Answer] **Orcs hate orcs.** Human groups hate other humans. Hutus hate Tutsis. Shia hate Sunni. Serbs hate Albanians. The orcs are even worse. Grudges within a family are more passionate than grudges with strangers and so too the orcs. Even more than killing humanoids of other races, orcs want to kill orcs from different groups. Different orc groups cannot get along for long. Tolkien actually made this an explicit aspect of the orcs in Fellowship. Several times in the books the orcs of Mordor come to blows with Sauruman's orcs. [Answer] Bad luck? Both the US and India had indigenous peoples and were both subject to incursions by outsiders possessed of the same levels of know how and technology, yet the indigenous population in India still outnumbers that of any descendants of Europeans living there, whereas America doesn't. One theory on how this came about is that the native populations were [decimated by disease](https://news.nationalgeographic.com/news/2011/12/111205-native-americans-europeans-population-dna-genetics-science/) and simply didn't have enough numbers to fight back. [Answer] There are many fantasy stories out there which have some malicious horde that works on a great cycle: every thousand years or so, they have amassed enough of an army to ravage through the civilized lands, pillaging and raping as they go. Heroes rise to the challenge; lives are lost. Entire kingdoms and nations wiped off the map. Eventually, the horde is either defeated or simply loses steam. Maybe they cannot sustain themselves; maybe the resistance is too brave. The particulars can vary, but a scenario which uses simple supply–and–demand doesn't involve any additional external components manipulating the savages other than them and their food — us. There you have it right there: They **are** “taking over the world” albeit periodically, but they aren't keeping it. Some other answers suggest similar things. This one differs in that the orcish predators or whatever are no less motivated during the interim, but like many predators they don't maintain a steady population. Of course, if your world of stories or games doesn't prominently feature some remark or exposition on this cycle, it rather loses the awe. E.g. events take place during the Swelling Of The Horde or something. [Answer] Just to expound on my example a bit, if orcs couldn't obtain nutrition from plants that are easily farmed, it would limit there ability to form permanent communities. After all, some of the first permanent structures humans build were storehouse for grain and seeds. Orcs, on the other hand, might only settle down in areas with a high concentration of animals or spend all there time herding animals across grasslands so they can eat them. If a large amount of orcs try to occupy an unsuitable area, they would overhunt their surroundings and starve. This would also make orc-based armies a difficult organization to plan for. Instead of carts of hardtack and gruel, they have to bring live animals with them to periodically slaughter and cook. Pillaging would also be less effective, as they could only eat what little animals the average peasant owned. If their lucky, an average household might get some chickens, a dog, and maybe a cow, and that's being extremely generous. Course, they might be able to justify eating the peasants too. Not cannibalism if their not your species, technically. That would make bands of orcs a heap-and-a-handful more menacing to see outside the city gates. That being said, I think orcs would be a lot better off if they settling among humans. As laborers, they can outperform humans in terms of lifting power and endurance. Or, if you got the resources, a standing army of orcs would be a heck of a deterrent and military asset to a nation. Just make sure you have a lot of animals for them to eat or orcs will be forced to leave you high and dry. Even without the meat-paying jobs, orcs could probably benefit from human farming techniques. As they have more stability and more time on their hands, humans might develop tools and systems that orcs would love to copy as well. Orcs might master horseriding and animal husbandry, but humans could invent the stirrup and calculus. Not that this would matter in the long terms, sense both species would learn from each other, averaging out the differences. This system might be able to have orcs that are twice as physically capable as humans, but humans have a lot more friends that live within shouting distance. It also has orcs as terrifying marauders, but also supports orc ranchers, construction workers, and samurai (originally I was just going to say watchmen, but this seems both more accurate and cooler). The species have respect for each other, but also a turbulent history. After all, its hard to live with "your granddad ate my granddad" and its hard to convince your orc toddler not to throw their human playmate over the fence and take their toys. That being said, reading everyone else's answers has been inspiring and helped flesh out my current solution. I would highly recommend shopping around to see what appeals most to you, dear reader. [Answer] This same problem is faced by some procedurally generated game histories like in Dwarf Fortress. If one race is overpowered then by the time you've run history forward they've wiped everyone else out. A fairly simple fix was to give each fantasy race a combination of climates and biomes in which they have a distinct advantage over all others. Empires can form and fall but almost always there will be a core that survives any defeat. The elves have a massive advantage in the deep forests, attacking the dwarves in their warrens of tunnels is a fools game, the human heavy cavalry hold supreme on the plains but get bogged down in the swamps that the orcs call home. Perhaps the elves live in an area with deep and treacherous snowdrifts but can ignore the hazards. [](https://i.stack.imgur.com/TmFNT.jpg) So, while the orcs are the strongest on neutral ground they don't have the advantage always and everywhere. If they face the elves or dwarves on the plains they have the advantage in strength but if they try to advance into their heartlands they get cut up by rains of arrows from the trees or cliffs. [Answer] As other answers cover why strength does not necessarily = superiority, I'll focus only on: > > Examples of an author successfully integrating any over-powered > species would be appreciated, even if its unrelated to orcs or other > species physically superior to human beings. > > > I would provide Tolkien as one example. The history of Middle Earth (up to just before the One Ring is destroyed), is one of the Orcs winning. Tolkien simply set his books at a time in the world's history when the advantage of the good races (that they existed first and thus started in front), has not been overwhelmed by the Orcs' advantages. The Orcs are winning, they just haven't won yet. The elves, eldest of races, are in decline. Their powers and numbers are nothing compared to earlier ages. They are leaving Middle Earth. Similarly, the Dwarves are in decline. The loss of the Lonely Mountain (recaptured in the Hobbit), and Moria as the two examples I can think of, fairly sure there were others. They are becoming even more insular. Humanity also is in decline over the history of LotR. Arnor is gone, the Dunedain mostly accompanying it. Gondor has lost territory, including both pre and during the LotR books. Rohan and Hobbiton are the only countries not in decline (and that is because they are protected by Gondor and the Dundeain respectively). Note that Orcs are not winning because they are stronger, they are winning because they reproduce quickly (and as grown adults rather than as children). The history of LotR is full of phyric victories for the light side, which never recovers to its former strength. The orcs are much quicker to recover. [Answer] Like the orcs in your story, neanderthals were stronger (and unrelated but smarter) than the homo sapiens. There are numerous theories for why they did not become dominant including: * Lack of Gender specific roles, All neanderthals performed all work equally where as homo sapiens learned fewer jobs but better. * Less contact between tribes, Homo sapiens technology would quickly spread through the species where as neanderthals took much longer. * Role of grandparents, Neanderthals did not seem to care for elderly so less experience was passed down from generation to generation. To prevent their extinction they could be much better adapted to mountains and night time so the orcs hide in the cold caves high above the humans making them hard to cull their numbers. [Answer] Humans did not come to dominate Earth so much that it hurts because they are bigger or stronger than other animals. Intelligence is the winning ticket in the game of evolution. As long as your orcs do not rival humans in intelligence and especially social intelligence - the ability to work together in larger and larger groups, to optimise distribution of labor and convey knowledge to others (both present and future), they won't stand a chance in the long run. A realistic story of the encounter between humans and orcs would be initial victories and conquests of the orcs due to war culture and individual strength, with the tables slowly but surely turning against them as humans learn and adapt, exchange knowledge and invent new strategies. [Answer] Orc's ARE way more powerful than humans. No doubt. But there are way fewer of them. They're so much bigger that they need more food so they keep smaller groups. Also, tremendous levels of testosterone make them very war-like, even with one another. They kill each other as much as they kill humans. And don't forget, they're not that bright. Don't tell them I said so but they couldn't come up with a plan to take over the world if humans outright surrendered to them! Plus they don't really want it. They prefer fighting over ruling. They're tough bastards for sure, but there's a lot of cons against them. ]

[Question] [ Average Medieval times for humans... And everybody fears these fire-breathing, jewel-stealing sentient creatures. There is just one problem. Dragons on this world are sparrow-sized, and aren't very social creatures. (So I don't think they will form a massive dragon swarm anytime soon.) Due to their tiny size, they can't torch down cities and steal princesses and do other dragonish stuff. What can a lone tiny sentient dragon have as weapons to strike as much fear as the typical Smaug-sized one? Being both poisonous and venomous is an idea. [Answer] Cities in the Middle Ages were flammable. Like, *really* flammable. London suffered from [two devastating fires](https://en.wikipedia.org/wiki/Early_fires_of_London#The_Two_Great_Medieval_Fires_of_London) and several smaller ones before the Great Fire of 1666 that destroyed most of the inner city. Amsterdam suffered two massive fires in 1421 and 1452, the latter of which destroyed three-quarters of the city. Lubeck in Germany burned to the ground three times in the space of 120 years. A dragon doesn't *need* to be dragon-sized in order to burn a medieval city to the ground. In fact, a sparrow-sized dragon would be able to flit around starting fires potentially without being seen, and *definitely* without being caught, unless someone nearby happens to have a (non-flammable) net or prodigious archery skills. No shotguns in the Middle Ages! Once those initial fires grow and combine into larger fires, it's already too late for a medieval society to do anything about it. Anything that's not made of stone, or sufficiently protected by firebreaks, *is* going to burn. Your house. The granary. The cathedral. *Everything.* So when someone in a medieval society sees a dragon flitting into town, they *panic*, because that means half the city is about to catch fire. [Answer] just to add to the other answers: Tiny dragons setting an entire city on fire not only is realistic, we have something similar in our world too: Let me introduce you to the [***Australian Firehawk Raptor***](https://nationalpost.com/news/world/australian-birds-have-weaponized-fire) [](https://i.stack.imgur.com/HZp67.jpg) This little sh\*t not only does start fires to force its prey to come out of hiding, they were HELPING spread the Australian bush fires. So just replace feathers for scales, make them do their thing at night and now you have a little devil who may kill you and your family while you sleep and its so small that there isn't really much you can do to stop them [Answer] I want you to meet: The Gimpy Dragon. <https://en.m.wikipedia.org/wiki/Dendrocnide_moroides> Like the Gimpy tree this tiny dragon grows hairs with neurotoxins in it that cause extreme pain for a few hours to days and then will keep hurting you to a lesser extend for months to years. And if you look at one of the names of this tree you can take a guess how much pain that is: the suicide tree. Unlike the Gimpy tree these tiny dragons can get pissed and fly into your face. Since they arent social dragons they are likely very territorial, so one sparrow-sized dragon that will leave trails of neurotoxin hairs near its nesting area for unwary people to brush against or step on that will get angry at people that get too close to its nests and fly against you and start fires for good measure? That is some terror right there in any time period. I wouldnt even trust a Hazmat suit when dealing with such critters. [Answer] ## It is a fatal mistake to think that the bigger the organisms the more dangerous they are. It is actually quite the opposite, especially when organisms are very small **or** *intelligent*. Consider bacteria or viruses that we can't get rid of. Consider most pests, such as rats or ticks. The best we can do (and that is 21th century!) is limit them in a particular area for a while. Now, dragons would be quite dangerous on their own, due to their small size, but add intelligence and they would *quite literally own the humans*. If they felt like it. Assassinations (either by poisonous bites, or, if they aren't poisonous, by carrying it), setting towns on fire as described in many answers, *spying* so they learn whatever humans are trying to organise to oppose them, herding animals into stampedes, for trampling or eating the corn, you name it and intelligent species will be the better at it the smaller and nimbler they are, compared to opposition. Humanity's only hope is in the fact the creatures are not very social and there is some limit to the amount of control a small group of them can wield. Still, a city would be at mercy of a single one. Or burn down. Or have a famine. Or have an invasion of raiders at the precise time when it can't be repelled. Or have their well poisoned. The possibilities are endless. Fungal infections, breeding vermin in hiding places,... I haven't even started. Seriously, I often have thought that the only reason ants don't rule the world is because they haven't got the intelligence for that. Yet. [Answer] Are psychic effects an option? You could make the tiny little guys have a cosmic-horror-style soul-piercing gaze that brings forth the darkest, most twisted fears of their targets. Or mind-control and a twisted tendency to play with it's victims by making them kill their families or something. Alternatively, they might breathe a hallucinogenic gas that did something similar. (See Batman's Scarecrow). Poison-gas breathing dragons are more of a thing in real-world mythology than our standard fantasy canon would let on. Finally, they might do some horrifying, insect-like skin penetration. Fly down someone's throat and burst out of their gut like a xenomorph? Lay eggs in your skin? [Answer] Of course they can burn down cities. Cities are made of wood. All it takes is one puff of flame and everything can go up in smoke. There is some reason to believe that Mrs. O'Leary's cow did not cause the Great Chicago Fire, but that springs from evidence not from any inherent implausibility in a kicked-over lantern causing all that death and destruction. And as they are so small, they can wriggle anywhere to set their fires. So basically you have an intelligent being that can kill hundreds of people and leave thousands of people destitute. If it targets granaries, it can ensure that everyone starves. The downside of their size is that if they actually want to weaponize it, they have to go and talk with people -- swooping in won't cut it -- and they may be vulnerable then. [Answer] People are pretty terrified of: * snakes * scorpions * tarantulas * wasps Which, I think, proves that size doesn't matter. You have the size of the dragon in your head as part of what makes it terrifying, but those people don't (although they might have stories of huge dragons like we would of huge tarantulas). You need to think of it like a scorpion or tarantula and maybe have a scene early on where someone is cornered by one, surprised by one dropping on them or coming on them from behind, maybe latching on to their neck and when they try to pull it off there are spines that cut their hands and cause searing pain. You need to give the reader the ability to feel the fear. The hair raising on their neck when they hear the sound of their wings. You might want to read real life accounts of attacks by small things. There's a (fictional) story by Dahl of a man that wakes up with a krait on his stomach under his bedcovers that might be of use. [Answer] They spit a napalm-like substance (or Greek fire, if you prefer.) Sticky, somewhat gelatinous and burning at relatively high temperatures of 800 degrees Celsius or higher. Even small amounts could cause serious injury or death if it landed on the wrong part of the body. If it got onto a flammable material like wood, the fire could quickly get out of control. If you wanted to take it to another level, have the substance automatically react with air so that even dousing it in water won't completely extinguish it. As soon as it is exposed to sufficient oxygen, it starts burning again. [Answer] It's as if you didn't spend any time in a tavern, lad. Otherwise, you would have heard plenty of stories by minstrels and all kind of travellers about all the nasty things dragons can do. They may seem small and harmless, but they will grow . There are also those that . Do you remember the [Great Fire of Rome](https://en.wikipedia.org/wiki/Great_Fire_of_Rome)? That was caused by a dragon. The [Sinking of Dongfang zhi Xing](https://en.wikipedia.org/wiki/Sinking_of_Dongfang_zhi_Xing)? That was also made by a dragon, angered because a merchant traveling there didn't give it a emerald it wanted. Not to mention that those evil dragons will grow to a hundred its size in order to eat you. Just a couple of nights ago, a guy from Elbonia explained us how his second cousin once removed was once in a ship with another passenger, whose aunt was the maid of the governor of Belgrade at the time when an elephant sized dragon stole them the royal jewels, and left after setting the palace on fire. You don't need your dragons to be big, evil, able to torch cities or steal princesses. Only that your widely believed folktales says so. Just hearsay will greatly exaggerate many trivial acts. But of course, your dragons being sentient, they could actually the source of many of those stories, as a way to protect themselves with such reputation (e.g. *everyone fears Pirate Roberts*). [Answer] **The Dragons Hibernate in Unlikely Places and are Hard to Find** The little buggers are problematic enough to a man in broad daylight, but they will go to sleep for variable times in many hiding spots. They fly for a time, undetected, then go to sleep in another. This means that even in civilized places, you may find yourself face-to-face with something that can melt your face off in seconds, that you can't reliably find, you can't easily fight. Latrines, granaries, temples, boots left open, library shelves, underneath bread ovens, wherever would be the least convenient place to find a fire-breathing thing suddenly fly out, screeching and clawing for your eyes, that's where dragons go. It's hard for a person to sleep well when the whole of the environment around them could suddenly have a terror in it, and tomorrow night there will be a different set of places. [Answer] Make the beasts look like spiders. [](https://i.stack.imgur.com/LA302.jpg) Source for the image above: <https://www.reddit.com/r/Sculpture/comments/eqtld5/self_dragonspider_dont_ask_how_it_happened/> I would totally freak out and scream like a little child if I saw something like that. Make it look like a [REDACTED] ROACH instead, and I swear that if one ever made it into my house, I would move OVERSEAS. [Answer] There is a story told in several different settings of armies catching birds from cities they besiege and attaching burning materials to the birds and setting them loose to go back to their homes in the cities and set fire to the thatched roofs of those homes. I don't know if that was ever tried, but ancient and medieval buildings and communities containing them were so vulnerable to fire that different people thought of that strategy and told stories about it that I remember. I have lived in Perkasie, Pennsylvania since 2015. Two 12-year-old boys playing with matches and paper started a few tiny fires that grew and spread and burned down a few blocks of the Perkasie business district in the Great Perkasie Fire of June 26, 1988, causing millions of dollars in damage. It was considered a miracle that nobody was killed by the fire. <https://www.mcall.com/news/mc-xpm-1988-06-30-2623531-story.html>[1](https://www.mcall.com/news/mc-xpm-1988-06-30-2623531-story.html) Of course modern buildings usually have a lot more stone, brick, and concrete than most medieval buildings did, and Perkasie had a much better fire department than a medieval city or village, but many buildings were still consumed by the flames. So small flying (?) dragons that can create small fires would still be feared by medievla people. What if the small flying (?) dragons are venomous like adders or cobras or asps? Medieval people were afraid of the local venomous snakes. And they would be even more afraid if the local venomous snake had wings and could fly and might fly over and land right next to you, so that you might not notice them and step on them and get bitten. If a large percentage of the people bitten by tiny flying dragons died, medieval people would always be looking around in fear to spot tiny flying dragons approaching. A lot of modern people are afraid of flying stinging insects, even people who aren't very sensitive to their stings and aren't in much danger of dying from a sting. If a higher percentage of flying dragon bites were fatal, they would be feared a lot more than flying stinging insects. A lot of people react with extreme fear to bats flying around, even though bats are mostly harmless. I expect those people would react with much greater fear to tiny dragons flying around if those dragons could spit fire or had venomous bites. [Answer] Speed. Hummingbird-like dragonets would be impossible to catch or stop. As soon as you spot one it has surrounded you with a ring of dozens of small (and rapidly-growing) fires and flitted away. They can perch on arrows mid-air, zip through the narrowest opening in the blink of an eye, burn the clothes off your back as you try to swat them. Just stay still and try not to aggravate them. [Answer] AUGH AUGH AUGH ANKLE BITERS. Personally, i jump and attempt to swat at anything that starts biting my ankles thanks to an unfortunate encounter with a cat a few year prior of this writing, and i would be pretty terrified of something that could set my ankles and also me on fire. not to mention that small dragons can usually go real fast and there would be close to no way to shoot them down. [Answer] Adapted from [current headlines](https://www.businessinsider.in/india/news/pictures-of-locust-attacks-in-jaipur-rajasthan-madhya-pradesh-uttar-pradesh/articleshow/76032310.cms): Dragons are like locusts. They are usually solitary, but due to a mysterious mechanism (*cough* meddling wizards *cough*, maybe) every so often they swarm. To densities of up to 80 million per square kilometer. Sure, a single dragon can't burn down the village, but when there are literally taking up more space than there is land, [](https://i.stack.imgur.com/DNhLr.jpg) random puffs of fire will quickly burn down anything... Of course, the crops don't fare well either. [Answer] You could use learned behavior to make something scary, even without giving it weapons. For example, what if all the forest animals are afraid of small dragons? They start to flee or hide when they see one, or fall silent when one is near. This would make their presence ominous. Humans would copy this behavior. But if it's all bark and no bite, people would eventually see through it. So I would suggest that regardless, they have a weapon of sorts. But it doesn't have to be a big one. [Answer] Think electric eels. Now give them wings and make them hummingbird size and highly aggressive--if it sees/smells/hears you, it zips over and kills or stuns you with the shock. Then it shocks anyone it encounters while escaping. Sure, throw in poison and fire if it fits the plot, but if I had evolved in a world with fast, flying creatures that could zap me to death or unconsciousness, I'd be instinctively terrified if I locked eyes with one. [Answer] Eggy weggs. What if they lay their eggs inside people. If they're sentient they could probably torture folks into doing whatever they desired, while slowly eating them from the inside. [Answer] Dragons are telepathic relays. If a dragon is near a group of humans then some of those humans will get random out-of-context fragments of what the others are thinking. This is quite scary, because you never know when some thought you very much want to keep quiet is going to be broadcast to someone else, and there are lots of stories told about how an illicit thought at the wrong time led to disaster, possibly including lynching. For instance, Joe Bloggs claimed that he got a thought from Pete Smith about murdering children, and Pete was subsequently lynched. Shortly after he stopped kicking several people got a thought from Joe about how he hoped they never found out it was a lie, so Joe got lynched too. [Answer] Make them mind-controlling parasites. The book series (not the movie series) of *How to Train Your Dragon*, by Cressida Cowell, has distinct subspecies of dragons that fall under the 'nanodragon' category. The vast majority of naondragons are based off insects. These dragons would be the same way, but based off parasitic wasps (oh, and Xenomorphs). One of these sparrow-wasps will stealthily fly around until it finds what seems like a good target (isolated, not paying attention, preferably an outcast so no one realizes what happened to them) and then it will fly up to the back of their head, jab their stinger in, and implant an egg. The egg will soon hatch, unleashing a worm. This worm will crawl in through the hole where the spinal cord goes in the skull to connect to the brain, and then it will pull an NPV (nucleopolyhedrosis virus) and liquefy itself, seeping into and taking control of the host's very brain. Eventually this draconic infection will cause the human to gain enhanced strength, speed, claws, and fangs, which it will use to bite and spread the infection. Sort of a cross between a *28 Days Later* zombie and a vampire. However, the first victim will become like Victor Validus in *Ben 10: Alien Swarm*: like the regular 'zombies,' but capable of spawning more sparrow-wasps, let's say from the mouth (Cressida Cowell's dragons have fire-holes, and it's hard to question the terror of someone opening their mouth wide, revealing a hole in the back of their throat that a sparrow-sized *dragon-wasp of death* emerges from). Just one of these things will cause terror and chaos, so no swarm or even grouping required; just one sparrow-sized dragon-wasp and a blissfully unaware human being. [Answer] The same reason why people are afraid of non-venomous garden snakes: the dragons fed on our early ancestors!!! Think of it, when our mouse-sized ancestors poked their noses out of their dens, the venomous dragons were waiting for them. Since the dragons preyed on our early ancestors, the fear has become so deeply embedded in our bodies, that we are still afraid of them even though they don't eat us anymore!!! Also, consider the venom factor. People are scared of venomous creatures because the venom can kill them. Apparently, the dragon's venom can kill a person with a single bite, which is why people are afraid of them. [Answer] * Hard body. * Silent * Fast * Hot (Some 900degreeC hot stone flying close to mach one an punching trough 50 wooden houses in 1 second may be a problem in a flammable city) [Answer] **THEIR BITE MEANS DEATH** These dragons have a terrifying poison in their fangs, known as Medusa Venom due to the way it works. A tiny scratch from one of this dragon's teeth is enough to coax a lethal reaction in the healthiest, largest human. But that isn't what makes it scary, or what gives it its namesake. You see, it's a poison that hijacks and spreads through the body, causing each muscle to spasm and then freeze in place as it locks it up. It's relatively slow-acting, taking up to 5 minutes to run its course, but there is no way to slow or stop it. The end result is a poison that slowly and visibly spreads through the body, paralyzing each body part it affects. The poison starts with the muscles that allow for motion, then begins affecting the internal organs. Eventually, everything but the heart and lungs are paralyzed, leaving the victim trapped in their own body. If there is nobody nearby willing to do the merciful thing, then the victim is left to slowly die of thirst and starvation, as their body's mechanisms for processing food and water are paralyzed and nonfunctional. [Answer] **Even Smaller Dragons** **Warning:** This answer is terrifying. > > The only thing scarier than a small dragon is an even smaller dragon. The Sparrow-sized dragons have larvae the size of a grain of rice. These larvae like to mature inside a living host. In particular they fly up the urethra -- drawn by their instinctual love of gems and the possibility of kidney stones up there -- where they attach themselves to the bladder wall and start sucking blood. Three months later the adult dragons eat their way out. > > > [Answer] ## Your Dragons are [Honey Badgers - they don't care](https://www.youtube.com/watch?v=4r7wHMg5Yjg) So, dragons can light fires, but nothing to take down a city or town. Sure they could build up over time, but people can fight back against them and force the dragons to flee. **Or can they?** Not if your dragons are pretty fearless - aggressive sparrows are tough to deal with if they won't back down. Couple of things a Sparrow Dragon has with a Honey Badger: 1. Dragons traditionally have very tough scales much like the tough skin of a Honey Badger, so they likely are hard to bite into, or through; 2. As a result of that, they generally aren't likely to be affected by poisons; 3. They'll eat anything they come across; 4. They hibernate at times to avoid more common predators. Things that Dragons often have that Honey Badgers don't? 1. They can *fly*. Good luck trying to get someone to hunt a Dragon as prey when that Honey Badger-like Dragon flies away with *its* prey - up their flfying ability a bit, and if they're flying away with a whole burned princess in their mouth...Yeah. Nobody's fighting that. 2. Dragon's have fire breath - to Honey Badgers' stink gas, that's actually much more likely to prevent other predators from doing the "Stealing the animals the Honey Badger was working to dig out of an area". What could Honey Badgers have that Dragons want? 1. An explicit ability to sleep off poisons, like the honey badger does ( See @2:41 of the linked video); if they are prone to feign death and then *just get right back up*, that'll bring in terror. 2. Extending their tough skin to be like Honey Badgers can withstand bee stings - if they're like that to, say, arrows, and spears, then they're basically nearly invulnerable, while being able to set fires. So...yeah; your dragons are honey badgers. [Answer] **Make them unbearably irritating.** What if the dragons are constantly squabbling over territory making loud growling and screeching noises, plus in the question, you mention gem thieving, think about it, you are a king just trying to address your subjects about some new decrees, and out of nowhere a pricing screech then a little flying lizard swoops down steals your crown and sets your hair on fire. I'd be scared for the longevity of my reign after a humiliation like that. ]

[Question] [ I've been thinking on it for a while, and it really doesn't make sense. If I'm a medieval dungeon engineer, designing a dungeon which will guard my vast riches, why in the world would I install a booby trap which isn't lethal? If I'm going to place something akin to the wealth of a nobleman in this dungeon, surely I have the funds to use deeper pits, sharper spikes, more arrows, more potent poisons, bigger rolling boulders, or more spell-casting scrolls. However, I frequently see these groups of adventurers who waltz in, plunder the dungeon, and waltz out with other king's well earned gold without so much as a broken leg! Why would those people make it so easy? I should surely make my traps with the intent to kill the most legendary foes! Merlin the wizard, Tiamat the terrible, and Xanathar the knowing will not be able to leave this dungeon without leaving their soul! Specifically I'm speaking of booby traps - not alarms, not guards, but plain, damaging traps. Bonus points if it fits within the narrative of Dungeons and Dragons 5e, or Pathfinder settings. [Answer] **Dead Men Tell No Tales** Suppose you're a rich viceroy or a dragon, or really just anyone that a band of adventurers / thieves might want to rob in D&D. Sure, you can make some really deadly traps, like using an Orb of Annihilation, but that doesn't solve one of your main problems. Getting constantly attacked is *annoying*. Here's the thing - thieves don't operate in a vacuum. So what you do is you solve your pesky problem with non-lethal traps. That way, the target is alive and thus you can do various things to solve the problem that you're being robbed. You can, for instance, if you happen to be a dragon, rake your claws down the hapless thief and horrifically scar him before releasing him back to the rest of the humans as a warning. You can also, if say you're a rich man who has been previously burgled, hand him over to the torturers to find out the who the thief sold the goods to. And, say, you're the BBEG Overlord. You can use your nefarious Cthullu-esque mental magic to read the poor rebel's mind to find out about the rest of the rebellion, allowing you to put them down with ease. In short, information is a valuable commodity, and it can only be capitalized when the subject isn't dead. (\*Unless you're a powerful necromancer, but necromancy tends to be expensive, at which point it's more of a cost effective measure.) [Answer] Same reason why modern armies use small arms, that are less deadly, than they could be. If the trap outright kills the unlucky adventurer, they party can just leave the corpse and press on. A wounded member of an adventuring party binds up resources. They spent time, bandages, potions to heal him, maybe he is hurt so bad, that they have to carry him around, seriously slowing them down. This puts stress on the party, leaving them vulnerable to the next line of defense. Other reason: Maybe they want prisoners to interrogate, as livestock, slaves etc. [Answer] ## I Think It Depends on What You Are Hiding, and Why ## The Treasure and Trap May Be Interacted With Daily In *King Solomon's Mines* there were the eponymous diamonds mines of King Solomon. Mine managers needed a place to store raw diamonds pulled from the earth between caravans hauling the goods back home, which (since the mines were remote) could be months, or even years. The trap was deadly, but something the managers could interact with every day w/ minimal risk: a extremely heavy secret door led down a long hallway that ended in the diamond store room. Only the managers (of which there were only a few) knew of the door or how to open it. The door was on a timer, and would close a few minutes after opening. The trap in *King Solomon's Mines* was deadly, but not instantly so (you died of starvation, or suffocation). Managers using the store room didn't need to remember what the trap was. They need remember only the far more general rule : the store room is trapped; do your business quickly and get out. Also, in the event a manager was trapped inside, one of his/her peers on the outside could notice their colleague was overdue, and open the mines themselves. Additionally, as the heroes figure out to their salvation, the engineers who were building and testing this trap didn't want to get locked in for every successful test. They built a back door to the storehouse, that the heroes intuited *must* exist and which, with a little searching, they found. ## The Treasure Might Be Yourself In the *Curse of World War II Gold*, members of the Japanese military were trapped by an invading army inside a network of tunnels in a foreign land. The imperial army had been looting riches from the government and people of all nearby islands and, since the regional command was stationed here, concentrated with this Imperial force. Trapped in the mountains, most of the deadly traps laid : land mines, poison gas, pits, cave-ins was meant to protect the army from the enemy. Meanwhile, the general ordered the digging of deep pits, around 200 feet deep). These pits weren't trapped. They were even marked in layers of material not native to the island as the pits were being filled-in, so that people retrieving the treasure could know they were digging in the right spot. The pits require an enormous amount of labor to unearth, so this effectively protects the treasure against random soldiers fighting back-and-forth for control of the territory. Someone must possess a stable hold on the land, and the ability to put a sizeable workforce together (hopefully the victorious Japanese Empire) in order to recover the goods. Because the soldiers were trapped in the mountains, the untrapped treasure pits were in the midst of trapped tunnels. ## Or, You May Only Plan on Coming Back for the Treasure Once In *Goonies* the crew of One-Eyed Willy found themselves running from the British inside a coastal cave. The entrance to the cave had been collapsed by British cannon fire, and One-Eyed Willy's ship and crew had been sealed alive. One-Eyed Willy's engineers manage to dig their way out of the cave. The captain and crew has a dilemma: they are far behind enemy lines; it will take them months, maybe even years to - get home, recruit a new crew, and get ships back to this spot. In this case Willy orders the construction of traps that, hopefully, they will only need to evade and disarm once. They plan to come back and empty the treasure cave, never to return. In this case, deadly traps keep the locals from working together to get at the treasure cave. Anyone accidentally finding the cave and traps is, hopefully, silenced immediately. Unfortunately, Willy decides to poison his crew at the last celebration before they depart for the wilderness. And the crew decides to poison the captain as well. ## Meant to Stay for Generations In *The Curse of Oak Island* a treasure was buried in a 200 foot deep pit, protected from outsides by a network of trap tunnels that would allow the seawater into whatever workings you dug, spoiling the pit. The traps weren't necessarily lethal, but easily could be. In this case, probably, the treasure was meant to stay put. Possibly indefinitely. Many of the theories involve that communications about the treasure include principals for disarming the traps (such as the location and existence of the traps intakes of ocean water). Similarly, in *Aladdin*, the entire Cave of Wonders is filled with poisonous treasures. The treasure is the trap. Only someone who knew what the real treasure of the Cave of Wonders is, the genie lamp, would be able to retrieve it. The lamp could be hidden that way for generations, as the way of defusing the trap is a very simple rule : only touch the lamp. This way, whoever built the Cave of Wonders kept the extremely powerful genie lamp within reach (should a national emergency occur), and could pass the secret to getting the lamp to his/her descendants; but at the same time, the extremely dangerous lamp was kept out of reach day-to-day. ## Never Meant to Be Found In *Temple of Elemental Evil* a deity of fungus oversteps it's bounds and becomes imprisoned at a location on Oerth. To keep anyone from ever releasing the fungus deity, layers of very deadly traps were constructed. In this case, the traps are never meant to be circumvented. The goal is to keep everyone out of the god's cage forever (or at least a very long time). [Answer] ## The Treasure is Bait Gold is not food [citation needed], and Adventurers are an excellent source of protein. The purpose of the gold is to attract humans - it's a feature not a bug. It's a lot of work to go out hunting, so smart Dragons have arranged for rumors about treasure, and they simply wait for the food to come to them. But Dragons are predators, not scavengers. They want their kill to be fresh, and enjoy the moment of the kill. Of course, this way the horde becomes a self-fulfilling prophesy. The adventurers bring in gold and magic items, which the Dragon keeps around because its easier than hauling it away. Thus the treasure becomes real. [Answer] I'll borrow a theme from the real-world modern security industry. Quoting from *Information Security: Principles and Practices, 2nd Edition*: **[Principle 1: There Is No Such Thing As Absolute Security](https://www.pearsonitcertification.com/articles/article.aspx?p=2218577&seqNum=2)** > > Given enough time, tools, skills, and inclination, a malicious person > can break through any security measure. This principle applies to the > physical world as well and is best illustrated with an analogy of > safes or vaults that businesses commonly use to protect their assets. > Safes are rated according to their resistance to attacks using a scale > that describes how long it could take a burglar to open them. They are > divided into categories based on the level of protection they can > deliver and the testing they undergo. > > > Granted that, security is always a cost-versus-effectiveness tradeoff proposition. Among the troubling questions one might ask from the dungeon-designers perspective: * Do I actually *know* the exact operational parameters of Merlin, Xanathar, etc.? (likely not) * Are there other possible looters in the world with capacities unknown to me? (very likely) * Will looter capacities change and evolve in the future? (also very likely) Hence: the "upper bound" of looter capability is somewhere between unknown, not knowable, and constantly changing. In addition, it's probably beyond the resources of any organization to meet even in theory (as per the real-world security principle). So one has to make reasonable judgements about risk-versus-reward and gauge the traps to that level. Also, assuming the dungeon-builders themselves want at some point to access the place, you'd prefer not to kill yourself with an overly lethal trap by accident. Two observations about that risk-reward: * D&D (for example) has a stark increase in capability and durability for advanced characters/heroes. A 10th level PC is something like 10 times the durability of a commoner, which is not a thing that exists in reality. So you can set traps that almost assuredly are really lethal to most people... but are not for heroes of 4th level (or whatever), who are possibly relatively rare in the world. * Early editions of D&D tended towards a much greater degree of verisimilitude in this regard; it was fairly common for traps to be "save or die" or even just "die no save" if the PCs took the wrong action. While some of us still like that quasi-realistic, easy-to-die play style, it received a lot of complaints over the years, and has mostly been safety-bumpered out of more recent editions. Arguably in light of that latter observation: Perhaps the legendary heroes and anti-heroes of the world are protected by the gods or supernatural forces such that there is simply no trap that can possibly catch them without fail. Dungeon designers are trying their best to make fully lethal traps; it's just that it's not an achievable goal in their world. [Answer] # Maximizing body count is not even your goal You don't actually *care* about how many adventurers your traps kill. What you care about is *being left alone*. There is no such thing as an impregnable defense. If you're going to booby trap something, what you want is an outer layer of traps designed to be extremely dangerous but not aim for 100% lethality. People spread the word 'stay the hell away from the Tomb of Hoarfrost' and quit coming around. Not extending this "courtesy" actually serves to *encourage* a certain type of adventurer to try and break in, more or less for the same reason some of the best DRM-breaking hackers do it purely for the challenge. # Booby traps are not cost effective anyway These things [never existed in real life](https://www.straightdope.com/columns/read/2217/were-ancient-tombs-really-booby-trapped/). People love using them in fiction because, well, *they're awesome*. But in general, the problem with booby traps is maintenance. The traps will need oiling. Dusting. Bows held at full draw for years will eventually foul and no longer fire. Who's going to do all this maintenance? People who work for you? They're not going to be big fans of hair-trigger death traps. This is the reason booby traps are illegal in the real world: the number of actual intruders they catch is far lower than the number of mailmen, utility workers, and so on that stumble into them. This is a good reason to use less lethal traps. Or will you try slaves, so you don't have to care they don't like it? This might sound more attractive to the less ethically-inclined dungeon master, but it's actually a much worse idea. Now you've got to keep a permanent population of folks highly motivated to "betray" you (not that they ever even owed you loyalty to begin with). The results are fairly predictable. [Answer] As a preliminary warning. It makes your neighbors annoyed with you if every time some drunken fool tries to break in, you kill him. Occasionally having to go drag him out of a pit and hand him back to his family is a small price to pay, especially if you can make it a humiliating experience, and it warns people that there are traps so they'd better not try it. Additionally, the price for making and keeping up a simple trap may be much lower than a more deadly one. Why use up the rare and expensive snake venom from the tropics when a simple pit will do? Save the venom for the guys who get through the first three layers of progressively nastier traps. [Answer] *For the same reason why there are people in MMORPGs who insist on playing against their own side, who spawn camp, who place teleporter entrances underneath your favorite hiding spot, who insist on standing in front of you so you can't shoot the dirty rotten rat on the other team. In other words...* # Your Dungeon Engineer is a Psychopathic Griefer But, really, how do you grief a couple of rangers, a paladin, your basic magic user, and some well-dressed dude sporting shuriken? * In one section of the dungeon, there's one whomping powerful spell in play that causes all *location* spells to cause the party to always take the right tunnel, leading them in a perpetual circle. * In another section of the dungeon the paths are all graded slightly to the left, forcing the party to either scrape their left shoulders against the wall or to hop slightly every other step, looking a bit like a teen be-bop band. * A devious spell is designed to play disco music sung by a chipmunk just after he'd been nutted by an angry gnome — and every time you cast *dispel magic* the music comes back with a different NPC name. * The skeletons are actually raven skeletons and they're under command to only peck.... * Every Kobold encountered by the party constantly chants, "trade your best hats at tradenpcdndforever.cc!" * Every NPC has a girl's name — just to get your hopes up. * Oh, and there is a treasure... you can see it occasionally through impenetrable bars, mirrors, and through cracks that can't be widened with any spell. *But there's no way to actually get to the treasure!* [Answer] Relying on traps alone to protect your treasure is a recipe for failure. A single competent thief with a 10' pole, a sack of rice tied to a rope, and 3-5 trained hamsters (among other standard tools) can slowly and methodically work their way through your dungeon, setting off the traps a safe distance ahead of them. If there's no time pressure, a thief could take days to make it through if need be. That's why you also need minions to patrol the dungeon: if the thief knows that a patrol passes through every 15 minutes, they won't have *time* to search for traps properly, so they'll actually set a few off, injuring themselves and probably alerting the guards in the process. (If the thief *doesn't* know that there's a patrol coming, the problem solves itself once they get there.) And I don't know about *your* minions, but mine always complain about poor working conditions if one of them gets decapitated every time they forget to only step on the prime numbered tiles on the way to the break room. But they don't whine nearly as much if it just drops them into a pit trap and they need to get call someone to fish them out. [Answer] Nothing as good as the answers we already see, but a few more: Traps that start out deadly, if not maintained, become not so deadly. This can include: * spiked pit that has already caught so many people over the centuries that the spikes no longer stick through the corpses * hinged tilting floor that have enough bodies trapped beneath them that the floor no longer opens 90 degrees but now just 45 or something; you slide onto a big pile of bones and take some damage perhaps related to how much you're carrying. Meanwhile a party of 3 or more can make a "human pyramid" up the tilted floor to get back up to the doorway. (Put some treasure down there--belongings of the previous explorers--but if they're going for it, have a chance the party has a moment where none is holding the floor down at its 45 degree angle... letting it pivot back up and entombing them. So mere happenstance isn't deadly, but the greed is.) * fast portculis that, due to wood rotting, only comes down half way, giving a good bop on the head instead of slicing you like a guillotine * rusty swinging mace or similar that is now squeaky and slower, giving just enough warning to jump out of the way, and if it hits you again no longer deadly * poison coating way past its "use by" date and merely burns your hand bad enough to keep from using it, not actually fatal * bowstrings broken or bows have too much shape memory to be effective: the party steps onto a dias and arrows simply fall out of holes in the walls all around them... * some kind of nondescript malfunctioning clockwork such that every time the party steps on location A, they hear scampering noises behind them down the hallway... no-one's there, it's just something that used to be fatal. Another idea for a "working dungeon", say where a big boss NPC keeps his troops quartered: you don't want the stupid troops to get killed periodically (bad for morale!) so rooms with a one-way door weighted to shut--meant as traps--also have a gong to call for someone to let you out. Perhaps a barred window in the door is meant to see the bait from outside, *and* let a trapped minion call for help if inside. Or, it has a one-way secret door to get out of, or catch that re-opens the main door, so that the master can go in and arrange the gold-plated bait trinkets without dying himself. [Answer] Dead bodies are a hindrance; they bring disease, and stink up the place. A booby trap locks the person or persons in, and then you hand them over to @Halfthawed's crew for interrogation :-). You might have ethical reasons against deadly booby traps, and consider them dishonorable. Or, you might be a bit dark, and take captured folks and put them in The Arena for your entertainment. That might warn off potential thieves as well. [Answer] There are two answers to this: the in-universe reason and the out-of-universe explanation... the latter being the most important. The out-of-universe explanation is that it's a *game*... a challenge, not an exercise in frustration for the players. A dungeon with traps so lethal that it's 'Roll another character' time if you make so much as one mistake isn't fun, it's frustrating. Frustrate the players too much, and they'll go play something else. So... when you get to the *in*-universe explanation, the out-of-universe explanation *must* still take precedence... so regardless of the supposed builders' motivations, certain design principles must be followed, that being the concept of *challenge*. You can't go from zero to lethal without some sort of buildup. Secondly, a *good* dungeon design intended to function for a long period of time should not rely upon devices that are single-use or mechanically complex unless part of the design includes the provision for active defenders who will be both willing and able to maintain them... However having active defenders is also a weakness... you can't guarantee their loyalty or abilities forever, and sooner or later, they might start to wonder why they're still guarding the treasure when they could be helping themselves to it. A good element of dungeon design should then include features intended to entice certain creatures to make the dungeon their home... you know the sort I mean: monsters who will either want to eat (or parasitise) treasure-seeking adventurers, or who are simply territorial, and will just want to kill them or drive them off. Ideally, these creatures won't actually be interested in the treasure. Now, that's not to say that you *can't* have lethal traps, just that the rules of the world are such that there *must* be a challenge... and not so much a "Whoops, you didn't notice X, so you're dead now." So, you have to follow the rules, you have to start with weak traps and deterrents, and gradually build up to the more dangerous ones, or else provide foreshadowing in the form of the remains of previous adventurers, so that should any of the player-characters die, the GM can say, for example, "You didn't stop to wonder *why* I said that there were all those skeletons with shattered lower limbs lying around?" It must be considered that the GM may be running a sandbox world, rather than a guided campaign, so at any point there may be challenges that are beyond the player-characters' abilities. The ultimate success of a dungeon from it's in-game designer's point of view must therefore be that adventurers arrived, attempted to penetrate its defences, and chickened out (and/or died) before reaching their prize... and that should they return, they would have to overcome all the challenges again, or perhaps new ones, considering that new monsters may have replaced those that were slain. Now, a game world and the real world share certain fundamental truths on the subject of security: 1. The best *se*curity is *obs*curity. If no-one knows about a treasure, then no-one will attempt to steal it. That's not to say that someone might not stumble upon it, or that someone who helped to hide the treasure might not speak or write about it. 2. Allowance must be made for the failure of obscurity... meaning that you still need a dungeon to guard the treasure. 3. History (both real and fictional) has shown that you can't (usually) take your treasure with you when you die, and if you can, you don't stash it in a dungeon unless it is also your *home*. So... since it is demonstrably better to bequeath one's worldly goods to one's descendants, there's no reason to do otherwise, except for three reasons: 1. No-one you know is worthy to be given your treasure, so your dungeon is a challenge intended to find a worthy recipient for it. 2. You delight in the torment of others, and your dungeon is a trap designed to inflict frustration, pain and loss upon them and their loved ones. Or 3. You have been misguided by others into believing that you really *can* take your worldly goods with you when you die... or for some reason, it really *is* possible. Most likely, though, either your stuff is really just going to be a temptation to grave robbers, or some shady individuals are going to try to substitute cheap, trashy replica grave goods and make off with your valuables, in the expectation that your relatives wouldn't desecrate your grave, and so will never know that a switch has occurred. However, either way, there probably won't be much of value for others to steal... the liklihood is that someone else stole everything before your grave was sealed, or your valuables went with you/followed you to whatever afterlife *you* went to, and since despite all the magic in the world, the law of conservation of value is inviolable, so any loot-duplicating magic like your loot staying in your grave *and also* following you to the afterlife is *not* going to happen. [Answer] ## Deception - plain and simple. Say your treasure is deep underground - you could have an elaborate series of traps and pitfalls - leading to a treasure chamber that looks like the real one, in a chamber shallower above the real treasure. It has been plundered of course - and your thieves are feeling chuffed that they had 'survived'. Then they think - of course the treasure has been stolen by those that came before them. They then return to their Thieves Den - reporting to their bosses and colleagues that they bravely and courageously went through the traps (and have the bruises to show for it) to find the treasure stolen. Whether they are believed or not, it is obvious the treasure is no longer at the site regardless and must be somewhere else now. Future thieves would come to the same conclusion. The long-dead owner of the treasure can rest assured that the best way to safely store his treasure is right under their noses, under the spot where the thieves thought the treasure would be. [Answer] 1. Your treasure is important, and you kind of want to be able to get it out again. A bunch of non-lethal traps is a nice way of keeping your staff on their toes as they say "well, lucky I didn't fall into the spiky acid pit of DOOOOOOOM over there". It reduces the amount of new staff you have to acquire, and the amount of treasure that has to be retrieved by draining the aforementioned acid pit is also such a hassle. 2. Trouble keeping your vicious animals fed? Meat starts to rot so quickly after it has fallen into a spiky pit or crushed with a boulder. So why not keep the meat alive instead? The traps might be non-lethal, but the animal that drags you and your party into their lair and devours you one by one over the course of a few weeks will take care of that. It's also a nice way to test your traps for maintenance during feeding time when you put some prisoners on them. You don't want your trap to be rusted shut when a party waltzes over it right? 3. There are two ways to keep your treasure safe: make sure it's a secret, or make sure no one would dare touch it. When someone comes by the treasure obviously isn't a secret anymore, so better let the local bar get a retired adventurer as permanent resident and make sure he has a nick-name like Legless Bob or Danny the Cripple. 4. On the topic of secrets, before Bob gets to have a quick weight reduction below the hips it would be nice to know how he got to the trapped place anyway. That way you can remove any interesting murals, locals that talk too much about enticing treasure instead of mutilation, information brokers or whatever else that caused interest to be had in your dungeon in the first place. Such people could either quietly disappear, or when the secret is out too much they could have quite public and gruesome "accidents" happen to them. [Answer] # It might also be that you want your treasure to be found You're assuming the type of dungeon that's made by the evil or semi-evil wizard who gathered up a treasure and wants to keep it to himself. But there's another type: The dungeon that contains a legendary artifact that is *only to be held by the worthy ones*. Obviously then your traps would not be designed to kill, but rather to kick the unworthy ones right back out the door, correct? [Answer] The more deadly the trap, the easier it is to evade. Think of the ballista trap, a trip wire launches a massive bolt guaranteed to skew anyone it hit to death. But, it only hits someone if they're standing in its path. So duck and do the 'penitent man shall pass' and everyone will be okay. Given thieves' and magicians' and clerics' ability to detect poisons, traps, predatory loans, and what not, it is a wonder that any trap ever hurts anyone. So the trap that isn't a trap. A cream pie in the face, or a moat that the raiders have to swim through to continue. The filling or the water might not be deadly, could be half of binary poison that is administrated by a later trap. Or it's pheromones of a Martian Thark in heat and the some of the dungeon's guardians are bull Tharks. One whiff of you, and it's death by bunga-bunga. Similarly harmless mold spores could be seeded along the dungeon. But they react at a later part, deeper in the dungeon, poisoning the water supply or busting into flame consuming everyone's food, spare clothes, and lamp oil. Things like this would consume precious resources that raiders need to steal your loot without really doing any direct harm to them. [Answer] I'm surprised this has been overlooked but perhaps our current users are fundamentally too nice. # The trap fires more than once, the first victim is bait for the rest. An adventurer triggers the trap and is now lying wounded and immobilised in the trigger zone. The adventurers will try to recover their wounded team member, the trap fires again. Repeat as required. This will have one of the following outcomes: * The entire party is caught by the same trap one at a time. * The party loses two members to the first trap and then spends the rest of their time trying to get them out without losing any more. * Two members of the party are caught by the first trap, from then on every time someone is caught in a trap they're left to lie and the rest of the group moves on with the echoing cries of their wounded friends following them down the corridors. [Answer] You are breeding a goblin army and need live wombs (plus the men provide decent protein for prior captures). Humans, elves and other females are able to birth larger litters than the purebred goblin females. Even better if your goblins are actually asexual parasites and could breed the male adventurers as well. [Answer] **Protecting the treasure isn't the point** If you build a dungeon, sooner or later, it's going to be filled with various creatures, from wolves to cave bears to goblins to ancient dragons. Frankly, as long as your dungeon is accessible and comfortable to the natives and wildlife, they'll keep moving in - especially if you seed it with a little treasure and some cheap magic items. Of course, goblins and wolves are a lot easier to deal with than ogres and dragons, and a lot easier to replace, too. If you filled the dungeon with grueling death-traps, there's a good chance that you'd kill off even hardy mid-level adventurers, which in turn means a lot of their equipment and treasure will be going to the local monster population, attracting even bigger monsters, which may well remove your access and claim your dungeon for their own use. Not exactly a good return on investment. No, deadly traps are right out. Instead, you want blunt arrows, shallow pits, rounded spikes, and feeble acid traps that wouldn't kill off a wizard with a -3 CON modifier, let alone an adventurer. You want your dungeon to be so bland that even a desperate mid-level adventurer would turn up her nose. Instead, you'll get a torrent of low-level adventurers, eager to break in their shiny new swords killing a goblin or two, and picking up a few paltry silver pieces for their trouble. Keep it easy, and the adventurers will keep coming back! ...And as long as they are visiting the "easy mode" dungeon, you can make sure they survive to spend their silver on the way in and on the way out, too, on cheap healing potions, basic weapons, and the leftover equipment from the few failed adventurers who couldn't dump sand out of a boot with instructions on the heel. The real treasure was not the friends you made along the way, but the hundreds of gold pieces you bilked out of novice adventurers by selling overpriced healing potions. [Answer] ## Dead adventurers are a *mess* Like, literally, they smell and then eventually they become bones. *Inert* bones, which don't make the dungeon more dungerous, but which cause lots of dungeon-upkeep problems; for instance, stack enough up on the spikes in your spike pit and the next hapless party lands with a squishy thump rather than immediate impalement. Likewise, a bunch of corpses bloated from poison is a dead (*hah!*) giveaway on the location of your hidden dart trap. And even worse than dead adventurers are *dying* adventurers, who will do things like get stuck in a puzzle room and then scrawl vital clues on the wall with their blood as they finally expire. *Those cheaters!* No, better to just wound them a bit and let them carry themselves out. Much more sustainable. [Answer] They only want to capture the intruder. Think about a lich. He needs to sacrifice live people in order to live, so wouldn't it make more sense to incapacitate the adventurers so he can sacrifice their souls later? ]

[Question] [ Gargoyles are bipedal, slow-moving animals that lurk on rooftops and eat pigeons. The rumors of gargoyles being magical construct are false; in truth they're just animals that have adapted to urban environments. By nature, the gargoyles are ambush predators; they have thick, craggy hide that gives them a stone like texture, and they can remain motionless for very long periods of time. They typically perch on high places, such as buildings or trees. They are good climbers, but also slow-moving similar to sloths. They have no natural predators simply because they're too difficult to eat. However, these gargoyles are also known for having wings. Two small wings protrude from their shoulder blades, with a limited range of flexibility. These wings are completely non-functional for flight; the wings are far too small and the body far too heavy to ever be airborne. So the question is; if not for flight, why else would gargoyles evolve wing-like appendages? What other evolutionary purpose would result in gargoyles having these seemingly-decorative wings? [Answer] Targeting. Your gargoyles are the modern descendants of creatures whose main mode of predation was dropping from trees into the heads of unsuspecting passers by. The wings don’t aid in flight but, like the tail of a dart, they do provide a tiny amount of control in where the rapidly descending gargoyle lands. This is critical for a slow predator like the gargoyle. It can’t chase after its prey. It either hits first time or goes hungry. If the prey shifts or the initial drop was a touch off then the wings provide correction as the bulky predators descend. Gargoyles without the wings simply miss and go hungry. Of course: it’s pointless to evolve these wings further. The gargoyles aren’t looking to glide or fly properly, they just need a tiny touch more control and that’s enough. Of course sexual selection means that the gargoyle with the most ornate yet petite wings gets the best mates, so... [Answer] The Wings are used for thermal regulation. Roofs get hot, really, really hot. Being able to unfurl a large surface area perpendicular to both the sun and the roof beneath allows the gargoyle to maintain active hunting well into the day when most other animals have slowed down. Also the mornings and evenings are quite cool. By unfurling their wings into the sunlight, or across a particularly warm piece of roof allows gargoyles to start hunting earlier, and maintain hunting much later into the evening. Again when many prey animals are trying to warm themselves up, or are slowing down due to the chill air. They remain quite small due to adaptive thermo-regulatory pressures. Mainly gargoyles with large wings freeze to death in winter. [Answer] **Vestigial** wings. Sea mammals got lower limbs tucked into their tails from tbe time they roamed on earth. Your missing piece is a common ancestor with other birds which started to get defensive meassures over mobility. If prey was available as nests or eggs, you don't need to be fast. Yet armor in shape of thick hide was handy to fend off angry fathers defending their nest. You may go as the condor, forsaking the head plumage to avoid infections from decaying flesh stcking on the feathers. Then gradually the other areas are also devoid of any coverage. Warmer weather mabye? [Answer] Balance and stabilization while climbing Much like a squirrel’s tail, or a tightrope walker’s pole, the wings of a gargoyle are used to help the gargoyle balance itself. Walking along narrow ledges, branches, and roof ridgelines, even slowly, is a risky endeavor. One wrong move could result in a lethal fall. The gargoyle’s wings, while useless for flight, do help it finely adjust its center of gravity, making it much easier to maintain balance. [Answer] ### Filter feeding Gargoyles will eat pigeons if they can catch them, but pigeons are a relatively infrequent meal because a gargoyle's success rate in catching them is lower than ideal. Gargoyles' primary food source is actually dead insects, leaves, and anything else that falls in the rain. (Occasional rains of frogs and fish are a bonus.) In the reverse of the normal body plan, the water runs into an inlet hole in the back and runs out of the mouth, having been filtered for any particles of nutrients on the way. The large ears and the wings together act as a funnel to capture as much water as possible. On the face of it, larger wings would seem to give some evolutionary advantage in increasing the rainwater capture area. However a gargoyle cannot fold its wings like a bird does, and gargoyles live in a very exposed, windswept environment. Strong winds are a real threat to a gargoyle with large wings, and any of the poor creatures who are cursed with large wings have to hide on lower, less exposed levels where the pickings are poorer and there are fewer mates. (The highest vantage point is naturally the most prestigious position in gargoyle society.) Some will try to tough it out at the higher levels, but storms will tend to blow them off the roof so they don't live long. Small stubby wings give enough water throughput whilst not putting the gargoyle at risk in high winds. [Answer] ## Camouflage Humans have always, and still do adorn their buildings with statues, and often these statues have wings. Over the ages, Gargoyles have evolved to more closely resemble these statues to better lay in wait for their prey, reducing the chance that birds and such will recognise them for what they are and keep their distance. It is only the urban gargoyles that where evolution has given them wing like appendages. Some forest gargoyles have instead evolved leaf-like protrusions. [Answer] Those appendages might not be good enough to fly, but do their job for allowing gliding and ambushing the pigeons. From high above the roof the gargoyle can wait for the right target to be at reach and then dive onto it, helped by the winglets in controlling the direction of dive. Then, after having consumed their lunch, they climb back to the tops where they lurk waiting for their next meal. [Answer] ## Parachutes Gargoyles occasionally fall off the roof. The wings slow down their fall from fatal to just painful. Note that the reason they have wings at all is bird ancestry, but the parachute effect is why these wing haven't disappeared completely. [Answer] The wings are purely decorative and use in seductive way. Like peacock does with their tails. Surely bigger wings show that you are a better gargoyles than the one with litlle one. or they could be used in combat, perhaps the gargoyles are fighting against each others to know which one will get to mate with a female gargoyles and their wings could be used offensively or defensively. [Answer] To steal an answer from the old Gargoyles TV show: they require way more energy than they get from food so the wings are also solar panels. The show gargoyles turned to stone during the day so they would collect and store sunlight during the day to power themselves at night. The show did actually try to explain that kind of stuff :) [Answer] I wish to combine Gustavo's answer with everyone else's, and raise an important point if you want a certain level of evolutionary "realism". Which is that "wings", as in, the recognizable complex flight-adapted limbs of most birds, all bats, pterosaurs, and so on, are massively over-engineered for all the purposes suggested here. You could imagine the gargoyles might have "simplified wings" that could be adequate to some of those simpler purposes (like the "targeting" suggestion you accepted as the answer), but I'm betting what you're picturing in your mind is not simplified enough for that, because if it were I'm not sure you'd be calling them "wings". In other words, none of the purposes described here would result in the evolution of *wings*, as opposed to simpler appendages. That's a strong claim to make, but I think the pattern in existing nature justifies it - only animals who fly, or whose recent ancestors flew, have wings. Plenty of animals glide, fall in controlled ways, thermoregulate, camouflage, have sexual displays, etc etc etc, and they generally have structures that are adapted for this, but almost never would you call those structures "wings". Because the visual appearance of wings is really hard to separate from their primary function, which is flying. However all those purposes are completely realistic uses for **vestigial wings**! "Vestigial" doesn't mean the organ is not used or even useless. It means the organ is no longer used for the purpose it originally evolved to fulfill, which typically means that whatever purpose it serves now, it's massively over-engineered for that purpose and it's pretty visible what its original purpose was. Which is exactly how you describe your gargoyle wings: they're small, useless for flight, but **recognizable as *wings***. Choosing a current "secondary that became primary" purpose for those wings can inform a lot of what your gargoyle wings are like; how small they are, how many degrees of freedom and muscle control they've retained, have they changed shape or appearance. But making sure those organs did evolve from wings frees you of having to worry about "but why would my targeting organ have this or that extraneous winglike feature". ]

[Question] [ I'm trying to work out the logistics of a little fantasy-historical piece I'm working on. Rome at the height of its power (c. 117 CE) has decided to invade a fantasy kingdom up north. It has a population of 1,750,000 and relatively advanced cross bows (the kind not used until much later by the French in medieval combat). This society however, doesn't have an organized army or militia on the level of Rome's, its population is mainly civilians, so the only chance in survival they have, is in their giant monstrosity of a wall which borders its entire territory, land and sea. The wall is on average 49 meters high and typically 14 m thick and solid. It's 10 m wide atop, so wide enough for a track to rapidly carry supplies. It's made of stone, brick, tamped earth, and some mixed-in limestone, and has a thinly polished quartz layer measuring 0.2 meter at the very top, to make it easily standable and maneuverable for those firing atop. There are no gates - exit/entry is done through ropes only given and accessible from the top to citizens and diplomats prepared to leave. This fantasy kingdom is only 156 km in diameter (area 19113 km² or 7380 mi²), but Rome wants it sieged and conquered. It's located in what would be modern day Germany and Belgium, with its ocean border facing the future United Kingdom. Its sea coast is also bordered: 8 m of this wall is under water, so towering 41 m up from the sea. Other than the technologically advanced crossbows and their massive wall, they possess no magic, no other superior technology or training. They have a paltry militia of 11,250, including basic infantry and crossbow archers, but definitely not the sophisticated formations nor training of a Roman legion. 2) Since this is fictional, and I'm trying for different scenarios to write it more practically, what if the land size diameter was upped to 250 kilometers (area of 49,087 km² or 18,953 mi²) and rather than crossbows, this civilization had middle medieval technology, such as powdered muskets and cannons. Does this pose a greater difficulty for Roma invicta? **What difficulties would the Roman Empire be faced with having to scale such a construction? (How) would it be possible?** [Answer] It's going to depend a lot on the wealth and organization of the society within. A dedicated militia of 11,250 like you mention might be enough to patrol the wall and hold off any attackers long enough to call up the general militia, but that's pretty well got to be the main strategy. Anything else has them too spread out to not simply be overwhelmed by sheer weight of numbers. Allowing minimal overhead for management and leave time, you're probably not going to have more than 20 men/kilometer of wall, while the Romans get to choose the time and place and can throw an entire legion at that same section, if not multiple legions. Even if everyone comes running from 5 km in either direction, that's still only 200 men. Sufficient to slow them down, but the Romans could be armed with pointy sticks and climbing up the wall by forming a human pyramid and they'd win unless the defenders have either extremely rapid transport, or the ability to call for reinforcements from the general population. So, if the society is wealthy enough that *everyone* has those fancy crossbows, and they are all reasonably good shots, then they can probably manage to repel a simple assault with ladders. Roman armor and formation fighting was formidable, but massed fire from crossbows of that power level would start to cause them problems, and probably at longer ranges than they could hope to throw their pila, especially when the defenders are atop a really high wall. At that point, it comes down to a combination of deviousness and wealth. The Romans are going to need either a siege ramp or tunnels (preferably both) to get enough troops past the wall fast enough. Building those takes time and costs money. Countering those likewise costs money. The Romans will build catapults and siege towers to provide cover to those building the siegeworks, the defenders will build catapults, counter-tunnels, and moats to stop them, and the loser will be whoever runs out of resources first, or fails to notice one of the enemy's gambits. Adding gunpowder to the mix makes a difference, but not in the way most people expect. The key thing about gunpowder is not that it makes the weapons more powerful. You could (and people have) build a crossbow just as powerful as a musket. A large trebuchet is arguably *more* powerful than early cannon. The thing about gunpowder is that it means that the source of energy for your weapons is no longer human and animal muscle. It can be stockpiled, and delivered in large quantities wherever and whenever it is needed, and it's not nearly so dependent on the physical fitness of individual soldiers. Again though, it will come down to wealth. With gunpowder and cannon, your special militia might well be sufficient without having to call up the general militia. A single cannon with grapeshot or (if you up their tech a little bit) cannister rounds could easily provide a similar amount of aggregate firepower as an entire regiment of crossbowmen, plus a heavy catapult; and a good team of three gunners could keep up that rate of fire pretty much all day as long as their ammunition held out. So the question is, "how much ammunition do they have stockpiled, and how fast can they make more?" The Roman legions were formidable, but keep in mind that, for the most part, they were attacking civilizations of a lower weapons technology level, and with lower military production capability. And even then, there were areas that gave them some trouble. A civilization with the infrastructure and resources necessary to produce late mediaeval crossbows in significant quantity could easily have sufficient resources at its disposal to make conquest by the Romans a foolhardy venture. Or, they might have built a few of the things, and then settled down to their nice, peaceful existence and nobody but the special militia even know which end of a sword is sharp anymore. That choice will make far more difference to the outcome than the power level of the individual weapons they use. [Answer] Laying aside the 112,000 man army (which is monstrous), I'll address Rome and the wall. Rome was entirely capable of working through almost any typical engineering problem involving such a wall. The thing about the Romans was that they were very patient. They would build a "camp" that might remain in place, working toward an objective for 20 or 30 years if need be. They would construct bridges over massive rivers that any other civilization would consider permanent, just to march an army across for a week, then destroy the bridge. Most people were in awe of their engineering prowess for very good reason. Of course, a 49m wall wouldn't require anything close to that level of patience. They would be over that in less than a month. Look up [the siege of Masada](https://en.wikipedia.org/wiki/Siege_of_Masada), where a group of Jewish Zealots held out on top of a natural butte fortress whose low side was 90m up with almost totally vertical faces. The Romans took about a year, but they built a massive earthwork right up that face. The used slave labor to do it, and they moved enough earth to permanently change the shape of the landscape. During this time, multiple Roman camps were built to cover the construction. Each of these camps had overlapping fields of fire from onagers, ballista, and other types of Roman artillery. These artillery emplacements would keep up a continuous fire on the part of the wall over the ramp, to keep the defenders from seriously impeding their progress. My guess is about a month to get over the wall you describe, but it might be a little longer depending heavily on the topography and geology of the location chosen for the breach. If they have better building materials available than they did in Israel's desert region (Masada), they could get things done faster, and if there were other problematic circumstances, it could take longer. The point is; once Rome decided to get over that wall, it would be gotten over inevitably. Your fantasy kingdom has no chance whatsoever. Edit: A note on crossbows: The Romans were extremely disciplined and well trained, and they had a formation that they liked to use against enemies using ranged weaponry called the Testudo (tortoise). Each legionnaire would lock shields with the guy next to him, and the row behind the front would lock shields over the heads of the guys in front, and the entire century would move forward in perfect sync as a block of men. Now, crossbows are unlikely to penetrate too much through a legionnaire's shield (this can be debated, depending on the crossbow and the time period in which it was built), so worst case, you do some damage to a few guys' arms, but then they are close enough to first fire off their javelins, and then move in for close combat with short swords. Basically, their default organization would make crossbows NOT very helpful in an open field battle. [Answer] # The Romans would mine the wall The reason that the Romans had to scale the walls at Masada is because it was built on a rockface. Mining into a rockface is hard, though it [could be done](http://www.unc.edu/~duncan/personal/roman_mining/deep-vein_mining.htm), slowly. Your wall is surrounding an entire kingdom. Therefore, I conclude that some point of the wall is built on nice, soft soil. Polybius' [*Histories*](http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0234%3Abook%3D21%3Achapter%3D26) (Chapters 21.26-21.28, 21.28 has the mining) has an account of a mine and countermining operation in the seige of Ambracia in 189 BC. Simply put, if you can dig under the wall, you can simply cause the wall to collapse under its own weight and enter the breach. That link is also some general good reading about how sieges went down in Roman times. Other good information can be found in Josephus' *War of the Jews* ([Bk III](http://penelope.uchicago.edu/josephus/war-3.html), Ch 5, Roman Camps; Bk III, Ch 7, Seige of Gadara; [Bk VII](http://penelope.uchicago.edu/josephus/war-7.html), Ch 8, Seige of Masada), the Tactics of Aelian (I can't find a free online version) and, of course, the granddaddy of them all Caesar's [Gallic War](http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Caesar/Gallic_War/home.html) which has seiges and camp building a-plenty. A pre-Roman (4th century BC) writer who has perhaps the best descriptions of siege warfare of any of the above is [Aeneas Tacticus](http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Aeneas_Tacticus/home.html). [Answer] You seem to have a severe lack of understanding of what the Romans were capable of, and the scale of things 2000 years ago. Logistics isn't what it used to be. The storage and preservation of food ***isn't*** what it used to be. Hygiene most definitely isn't what it used to be. ### Food and hygiene Packing that many people in such a small area in medieval times will result in starvation, and quite probably outbreaks of terrible diseases. Agricultural productivity in medieval times was quite abysmal. Crops would fail all the time. Entire herds of animals would get sick and die. Thousands of people would die in a famine, and it would be no more than a sad event in a long list of similar ones. Disease was rampant, and only a small percentage of children - the strongest, and luckiest - would make it to adulthood, not to mention the many adults who would also die from something as simple as the flu. You're packing a lot of people in a *very* small area. Sure, we do it today, but that's because we import food from half the world away via trains, trucks, etc. There are thousands of trucks driving into any given large city at any given time of day. If those food shipments stopped for even one day, you would notice shortages immediately. No more fresh bread. No more fresh fruit. Canned food stuffs would start flying off the shelves. We live in a very delicate balance in the big city. Your 1.75 million people will be in bad shape in such a small area. ### Your army and defenses A wall 50 meters tall, 14 meters wide, and 156 km long is not just incredibly difficult to build, it's also a terrible defensive structure. You've essentially built yourself a fancy cage, and don't even know it yet. A wall needs to be constantly maintained (financial drain), as well as manned. Not to mention, that people need to get out, so you'll have lots of gates, which means weak points which can fall to the enemy. Now on to your army. A modern country can only maintain an army around the size of 10% of the population before it starts running into economic woes. In war times it will rarely increase above 15%. Not sure how you're going to feed and equip 112,000 people, as these numbers were not encountered in medieval times. Some of the most famous battles of medieval Europe were fought with 5000 people or less on each side. Even assuming you can keep your people fed and healthy however ... ### You will lose The Romans were the very embodiment of ***"improvise, adapt, and overcome"***. Their armies were not always larger than their enemies, but they were highly trained, highly organized, and well equipped. They were renowned for upgrading their armor, shields, and weapon designs based on tips and tricks picked up from conquered or enemy nations. Your main weapon - crossbows - will only help you as long as their legions are further than arms length away. Furthermore, once the Romans come in contact with your troops and capture some of those weapons they will very quickly end up being used against you, and their armor will be improved to provide better resistance against them. But I don't think this will even happen until after your nation has fallen. Here's how I think it would all go down: The Romans will scout your walls, see where your defenders are more lightly concentrated. They will look for a weakly guarded gate, or a place where they can more easily approach the wall with ladders and remain undetected (perhaps due to a nearby forest) They will then strike, and own your wall before you even know what's happened. Their concentrated and well trained troops will then hold what they've got while their comrades storm through the gate, or over the wall, and establish a bridge head. Once their troops are assembled and in formation within your perimeter the war is essentially over. They will advance in formation, behind a shield wall, close with your defenders, and slaughter them. A few legions fighting in a determined and organized fashion will wipe out an undisciplined force 10 times bigger without issues. > > **Note:** it's important to understand that a force will lose cohesion, and people will start running away long before most of them are dead. It's estimated that in medieval battles ***fewer than 30%*** of the troops would die on the battlefield. The rest would simply break ranks and run away when things started going south. Romans are a notable exception because their forces were highly disciplined troops, trained to fight together, and obey their chain of command. That sort of discipline was essentially unique before them, and wasn't really encountered again until much, much later. > > > I doubt a long siege with bombardments, and fancy siege machines would even take place. [Answer] The point of a siege is to cut a city or castle off from the outside world until they surrender or die of starvation. Since this is an entire hermit country, the classic idea of a siege is meaningless, what you're looking for is how to assault the kingdom. With your now reduced army of 11,500, you have ~23 men per kilometre of your 490km wall. Not too bad for a patrol, but what are you going to do if I just roll my covered battering ram up to your wall and start cutting through? What if I started doing this in 2,3,4 places at once? As soon as you start focusing your defences on one point in the wall, you create weaknesses elsewhere and I can afford to put a couple of legions up against a kingdom of that size. 49 meters is a really big wall, too high to bother going over when you can go through. A wall is a built thing, given enough time it can also be dismantled and you don't have enough men to guard a wall that long against a superior force. Also I'm damaging the outside of your wall, you need to get men to the outside to repair it, which means dropping your guard and exposing civilians to danger. Various other siege techniques would also still work, digging under and collapsing a tower for example. Prop the tunnel with wood so it doesn't collapse on your workers, then pull out the people and burn the supports when you're ready. Given cannon, it's a matter of where you place them but it could well hold. With such superior firepower the wall is less relevant, what you want to do is meet a turtle on the open field and just lay into it with the cannon. Roman defensive formations were good for the enemies they had, but not against cannonballs. The problem however, is once the Romans have seen cannon, they're likely to come back with something similar on the next round. [Answer] Brushing aside the realism of the kingdom and its wall, let's go on to tactics. The real logistical problem is not so much the wall, but how to move troops and supplies in and out of the territory once the wall is neutralized. Without any gates, there's no way to effectively do this without tearing down the wall. So, as the Roman commander, my mission is to tear down that wall Mr. hankhoward. The simple way of doing it would be to scout a way to undermine sections of the wall, and create a nice, big gap in it. A wall that big needs a lot of support, so destroying it from the foundations seems easiest. Let's assume your engineers thought of that, and sunk the foundations deep into the bedrock, or used some other methods to prevent undermining. Using the mighty engineering knowledge that Rome was excellent at, my scouts would identify the weakest portions of the wall, and line up ever onager, ballista and trebuchet I could manage and hammer that wall for as long as it takes to make a hole. Doesn't matter how thick your wall is, eventually it will fail to that assault. I don't like the dirt ramp option, but it is an option. The reason I don't like it is that it still makes transport of munitions hard. If I have a nice, big, hole in the wall, I can move my equipment through easily, but if I have to move everything up a ramp and over it, it becomes more difficult. Not to mention that I want Roman citizens to eventually colonize and trade in this land. EDITS: A rule of cool option would be to set up a bunch of scorpions or other ballista-like siege engines and mount ropes to them. Run a bunch of legionnaires up to the walls, support them with archers to keep the enemy's heads down, and fire ropes over the walls. Legionaries climb up the ropes and take the wall. You could also do this with siege towers, ramps, or anything else, but the idea of firing ropes over the walls just seems cool (provided you could find a way to properly anchor them and keep them from getting cut). You could combine this with a distracting attack to keep the defenders concentrated in one area so your ropes don't get cut. I also would like to see the option mentioned in another answer where the romans divert a river into the wall to undermine it. The best part about that plan is that it is relatively low maintenance once started (it just takes a while). [Answer] One idea that hasn't been mentioned yet: Plant trees. Specifically, quick growing plants like pine. Plant them densely, right up to the base of the wall, or close enough. Start by planting a dense ring just out of crossbow range, wait till the saplings have grown a bit, so as to give cover, then plant another ring further forward, wait for them to grow... until you reach the walls, in ~80 years. In a few years, they'll grow high enough to cover people moving on the ground. The defenders will either have to come down to clear the place by hand, and get picked off by your patrols, as they approach the treeline in the open, or give up their major offensive advantage: crossbow bolts can't very well hit what crossbowmen can't see. Unless, of course, they get a very dry summer and try to set the forest alight, then risk suffocation, as the smoke pours over the wall. Now that you've got cover, you can do as you please to the wall, whether you divert the nearest river to play Ents and Orthanc, or dig under it, or build hundreds of rams from trees on the outer radius of the tree ring,or have ballistae/catapaults targeting the wall from under the tree cover, or even simply sneak long ladders close to the wall and raise them at night to infiltrate the country or just seize the wall. The dumb part of this kind of defence is that you only need to capture the wall, and you get strategic command of the country. The inner side of the wall must have stairs for access, otherwise they'll never be able to reinforce the defences, and the invaders can simply pick the reinforcements off as they stand around helplessly. Hold the wall, and you can simply have your people walk down into the country. Regarding the advantages of muskets and cannon, they might actually prove a liability. Why? Simply because of resource requirements. You need sulphur, carbon and saltpetre for gunpowder, lead for shot and steel or cast iron for muskets and cannon. Then you need heat sources, either coal or firewood for casting balls (both shot and cannon-)and tubes (cannon and musket barrel). You need lifts and winches to get the cannon and ball up the wall, shelters to keep your powder dry and safe from fire. All these will need to be extracted/manufactured, which requires manpower, or imported. And you can't import because some bright spark decided to wall up your seaport as well. That leaves you with extracting/mining and manufacture, drawing people away from useful work like growing crops, repairing infrastructure or simply manning the wall. And it's only useful until the Romans figure out that the strange powder is very inflammable and the magic weapons are useless without it. Of course, if by then you've managed to convince them that you have Jupiter's favour, you're safe. Otherwise, they'll take potshots at the top of the wall with flaming bags of plant matter soaked in oil, and hope they manage to hit one or your caches. And you'll probably run out of powder before they run out of dry grass and leaves. [Answer] 500'000 m of wall, with 11,250 soldiers to guard it. Account for sleep, training, and other duties, and at any time you'll have no more than 3,000 soldiers to guard that 500'000 m wall. That's 3 soldiers every 500 meters. Enough to let you know when the wall's been breached, but nowhere near enough to even consider defending it. Walk up to the wall, demand a surrender, done. --- You can climb it, launch a mass of ropes, tunnel it, use a spy, attack through the water exit/entry points, poison the water supply, etc. Crossbows with their low rate of fire are quite useless if we look at the numbers: 3 soldiers firing at a 500m wide mass of soldiers, at 1 bolt/minute, while the soldiers climb the wall for 2-5 minutes ... They'd be better off either trying to cut the ropes (3 people vs 400 ropes, good luck), or more realistically, running away. Sure there are some more elaborate ways to attack, but since the army can strike anywhere at any time, anything other than either a night attack using lots of ropes, or a spy / bribed guard, seems like a waste of time and resources. [Answer] 1. First dig a tunnel. Getting a large army in by rope is not a option. Since the Romans can't fly, the only option I see is a tunnel. 2. Bribe the guards. The Mongols were able to get past the Chinese defenses and into mainland China by simply bribing the guards. The Romans could use a similar tactic. 3. Live off the land. One of the things that made the Mongols so formidable was that they had no supply line. They took everything they needed from their enemies. َ [Answer] **Dig a Tunnel** You do not list how deep the wall goes in land (only 8m in water) so I am going to assume 8m in land too. The army could build a stone wall to protect themselves from attacks from inside the wall, and behind the wall tunnel into the ground. The tunnel would go under the wall and up into the city. Troops would then move in at night through the tunnel and attack. Multiple tunnels could be used in order to create a larger attack. Also tunneling directly under the wall could cause it to possibly collapse enough for ground level entry. [Answer] Trebuchets with fire and disease. Trebs could easily put things over the walls and splatter burning oil on sections of the wall to isolate it from reinforcement. Attacking is not about matching numbers of force, that is game stuff. It is about creating the most massive force imbalance at some point you possibly can, then exploiting that imbalance. Expanding on the treb with burning oil example, some siege towers 50 meters from the wall (crossbows are not powerful that far away with longbowmen(they reload much faster) to pick off anyone up there. The force imbalance is the locational attrition. The city-state will be getting no reinforcements and every person on the wall that picked off is one less to respond... and one more to convince the rest of the citizens that resistance is dumb. The trebuchets keep up the fire and disease bombardments. Two or three towers are built from wood ( a week at most) to allow surveillance of the city as well as spotting for the trebuchet corps' efforts. Once the wall is cleared in one section then build fires at the base every day. Masonry is not heat resistant forever. A section of the wall will come down and the Romans suffer few if any casualties. The wall has served to be a force imbalancer... on the side of the Romans because it prevented the city dwellers from ever using their more powerful weapons in a useful way. City had really stupid leaders and generals. [Answer] Others have noted Roman military capabilities, which certainly are enough for the job. Instead of repeating those I will point out a critical difference between Roman and modern psyche. It is hard for us to understand Romans because they, in their height, looked not at Rome's power as a undisputed permanent fact. We often say that the Romans overengineered their solutions, but that's only our standpoint. One born in a world where making a 3-year industrial investment is nearly unheard of for most parts of our current world. Sure we can build some infrastructures longer. But in essence we are living in a world where we can not justify many mega projects and instead keep maintaining ones that are well past their prime, because we look at the world one quarter, maybe a year at the time. Generations before us did not have this problem! China, Egypt and Rome were built to last. Romans were not afraid to do investments that spanned generations. This spells doom to your fantasy kingdom. The Romans could afford to spend years and decades on this siege. It is nearly impossible for us to understand what it means to be able to focus so much in human resources. It is a totally different ballgame. On top of this the fantasy kingdom's defenses are not beyond the capabilities of Roman engineering. [Answer] Many good, long and detailed answers. I'll try to make it short and answer only the question you asked: Rome would have absolutely no problem at all to defeat that wall. They proved this in the Siege of Masada (a mountain fortress), where the Roman army spent months constructing a huge ramp. Rome would also absolutely go and do this, no matter the cost, time or effort. Rome, especially at the height of its power, was very much interested in keeping its reputation as part of psychological warfare, and part of that was that Rome **always** wins a siege in the end. [Answer] Assuming your kingdom shape is a circle, 156 km diameter means that the circumference is: 490,000 m So from a logical point your fantasy kingdom have enough people to keep the wall guarded: It needs just one person every 100 meters or so, so just 4900 people are needed and the population is over the million so just 1-2% of population is needed for guarding the wall (well, in reality triple that value assuming each person works only eight hours a day). * Now to put a ladder and climb a wall of fifty meters. You just need 1 minute. * The world record running speed is just slightly above ten meters/second * In the time a single Roman climb up a wood ladder, only six guardians can come to help, leaving 600 meters of wall unguarded. If you mass up enough Romans they can just climb up and start invading. * Assume you put one Roman every five meters * Assume a defender can throw away one ladder every three seconds Then you just need 120 Romans to get a bunch of them up to the wall (in reality that only if six defenders can gather instantaneously, which is impossible). If you have 130 Romans you can get for sure ten Romans on the wall while defenders are just six. Advancement in bow technology is not relevant, because if Romans are so few you cannot kill that many of them (bows are effective against tightly packed enemies). Again assume defenders have perfect aim and can shoot one arrow every three seconds, or they shoot or they remove a ladder so the total number of Romans to get up on wall do not change, but you need some extra Romans to get near the wall: * Bows have 200 meters range? (100 meters for perfect shoot, and 100-200 for 50% shoots) * Romans run at five meters/second * A Roman takes 200/5 = 40 seconds to reach the wall * Assume 42 seconds, that's 14 extra shots with perfect aim, and 11 with normal aim * since there are six defenders you have 66 extra shots In the end you just need 200 Romans to get ten Romans up the wall. If you do that in many places at the same time, you conquer the wall. Or you can just amass an army along ten kms of walls to get some hundreds Romans on walls. Now, is a fifty m ladder feasible? Probably not. But you don't need wooden ladders; just give enough bows to Romans. Do they have shorter range due to lower technology and height difference? No problem, you just need some time to move more Romans near the wall. Defenders have to die due to arrows or to retreat to keep safety range, in both cases leaving a piece of wall unguarded so that Romans can start demolishing it or climbing it. Also, I would not be surprised if Romans would be able to put rope ladders (throwing rampling hooks) working within 1-2 hours and within few days build a more stable way to cross the wall. [Answer] The Romans were a formidable military power, but they weren't invincible. There was a stalemate against Persia and Armenia, and they also were hemmed by Aksum (controlling both banks of the Red Sea). They also stopped conquering land when they thought it wasn't worth the effort (e.g., they never conquered Scottland or Ireland, and they gave up on conquering Germany). The walls are technically not a problem for the Romans. The size of the army is a real problem, and the crossbows are another problem: They will cause heavy losses among the Roman legions. Probably, the Romans would acquire the crossbow technology sooner or later (by espionage, treachery, or reverse engineering from artefacts found on the battleground). Still the army of the fantasy kingdom is much to large for the Romans to overcome. They can hope the the fantasy kingdom does not try to conquer Rome! EDIT: I see that the army was decimated by a factor of 10: Now it is feasible for the Romans to win, but yet very hard. [Answer] Such a big wall will be impossible to defend with only 11,000 people. If the diameter is 156 km, the circumference is 490 km, a diameter of 250 km gives us circumference of 785 km. The smartest thing would be to put most of your army at the center so that they are "only" 78 km (or 125 km) away from any point on the wall. Say the Romans attack the wall and are trying to scale it. Your wall guard has to travel 78 km to notify the army, then the reinforcements have to travel back 78 km to the wall. The Romans have much superior numbers; they can launch simultaneous attacks, scale up the wall and establish a beach head for the rest to follow. At that point the question is if the superior technology the defenders have gives them enough edge over the Romans. I would say no. Medieval firearms were under-powered, inaccurate and not very reliable. ]

[Question] [ Given a fantasy setting with necromancers that can produce armies of undead, would such an army really be useful against a fully-equipped but smaller human force? Given that: 1. Zombies in this fantasy setting are magic based and are therefore unaffected by head injuries like other zombies. 2. Zombies in this fantasy setting are smart enough to hold weapons, but not smart enough to wield them with any sort of skill whatsoever. 3. Zombies in this fantasy setting usually wear armor. 4. Zombies in this fantasy setting are controlled by necromancers, but the zombies in this fantasy setting don't seem to be able to understand anything except for the most basic of commands. (Attack, don't attack, move right, go left, and so on) 5. Zombie army is shown to only use infantry units, with no cavalry or archers. Also assume for the sake of argument that the human army has let's say ten thousand men (half as much as a zombie army), made up of an equal number of: 1. Knights in heavy armor on horseback, 2. Lightly armored foot soldiers armed with shields and swords. 3. Heavy Longbow men. 4. Pikemen. 5. And have a small wooden Fortress that they can retreat back to. All the men are well-trained professionals with competent commanders who know the strategies used throughout the Middle Ages. My question is: would a zombie army really be an unstoppable threat (as shown in Game of Thrones and other fantasy movies and TV shows) or would a well trained, well-equipped medieval army with competent commanders easily destroy the less intelligent and untrained undead even if they were outnumbered? Or would their lack of intelligence, skill, and inferior strategy make them easy prey for any competent medieval army? Also assume that both sides have the resources to provide for at least light armor for all of their soldiers and heavy armor for their knights. To clarify zombie army has 20,000 zombies, while the human army has 10,000 men. [Answer] The difference between this and GOT is that in GOT, they aren't just outnumbered 2-1, it's far worse than that. Where zombies excel is not in attacking knights on an open field, but in use by necromancers to attack fortifications. A pile of hundreds of them directed by a necromancer can help get them over and through things. While the individual zombie might not be so bright, the controlling mind might be. Hardholm in GOT features strategy used by the White Walker in charge, using the mindless hordes. In this case simple commands were used to great effect. Strategies that humans can use: * Aim for limbs, specifically legs, but also arms. If they can't swing a weapon or walk, then they won't be as useful attacking. This is counter to aiming for center of mass, which is what you normally might do against an opponent. * Develop specialists and special weapons to decapitate. You said a head shot doesn't work, but if removing the head will, then there should be some elites that can do this quickly and well. Things Humans should not bother with * Setting them on fire. Oh, it seems like a good idea, until they start walking towards you, on fire. * Archery. The reason why it's effective against humans is because they bleed to death or something vital is hit. Zombies don't have that, and most archers won't be able to totally take out a limb. Also, picture a Zombie filled with arrows. They now have a measure of protection from bladed weapons, because they've got to get through all that to strike. Unless the archers use this to pin and slow them, in a specialized manner, it's not going to be all that helpful. * Horses. They are more of a liability (you could get easily get pinned) against such a foe. For the specialists lopping off heads, this could be ok, but if you are targeting limbs rather than the neck and head, it's actually going to be harder to disable limbs from a horse. Your commanders actually have to have experience in fighting these zombies in order to be effective. Otherwise they will strategize according to what they know--things like, an army tends to stop when arrows are raining down (these won't) and the concept of shock and awe simply won't work. In most battles, when the tide turns, a certain number of the enemy might flee. These won't. And if your dead can immediately be turned against you, you may not stand a chance--that's a big, big deal, and if true, your 10,000 may not stand a chance. But your question is: Zombies, unstoppable threat vs. easy prey in your scenario. Answer: that depends on how smart and experienced at fighting this threat the commanders on the human side are. And if their own dead can be turned against them. Unfortunately, shock and awe does work on the human army, and the effect of not being able to stop them in the same way as humans could cause morale problems. [Answer] ## Watch out for fatigue The other answers, especially of [Erin Thursby](https://worldbuilding.stackexchange.com/users/23058/erin-thursby), covered pretty much the subject : forget the archers, have pike formations and shieldwalls, aim for the limbs and consider how well your soldiers are trained for this kind of threat. However, one important variable for your battle is fatigue. Fighting in heavy armor with heavy weapons is incredibly weary, most than people usually imagine. You can't fight non-stop for hours, 10 minutes are well enought to get you on your knees. Usually (aka in the real world), both armies are made up of humans with the same resistance to fatigue. But here you have zombies. They do not die easily, and they do not get exhausted. Never. They will fight until the last one of them is butchered into several pieces. If both armies were of the same number, the humans could make rotations in the front row, allowing the soldiers to take turns to rest. But being outnumbered means that they can be flanked more easily, and partial retreat may not be an option. Thus, fighting in a natural corridor preventing the zombies to flank your army could be quite easy, but on an open field... not so much. Because of that fundamental difference in fatigue between humans (*"My heart will explode !"*) and zombies (*"Ghâââ..." = "Don't care"*) **exhaustion would become a far greater issue than one could expect.** [Answer] # Every battle is won before it's fought The other replies have pointed out a lot of the horde's tactical advantages, but those are arguably counterbalanced by numerous tactical disadvantages. Either way, dwelling on tactics is ignoring the most important element of warfare. The horde would win because it has **utter logistical supremacy**. To wit, zombies: * Have no need to forage or protect a supply train. Meaning they're significantly more mobile than their human counterparts, on a strategic level. This is already a tremendous advantage, giving the horde much greater control over when and where to fight. "Speed is the essence of war", "He will win who knows when to fight and when not to fight" and all that jazz. The ability to weather a siege indefinitely is another plus. * Are immune to frostbite, disease, and heatstroke. In other words, they're basically unaffected by attrition, and can safely traverse all sorts of perilous terrain, enhancing the aforementioned mobility and further cementing their ability to choose the site of battle. * Never sleep, and are generally unhindered by darkness. This is first and foremost another massive mobility boost. It also gives them the edge in night attacks, which already soften some of their tactical flaws (comparative lack of martial skill; darkness is an equalizer) and augment their psychological strengths (fearlessness and a demoralizing effect on the enemy). And since we've already established that the horde has the initiative, there's not much the humans could do to prevent most of the fighting from taking place at night. If the humans discourage night attacks with expertly-fortified camps, the zombies are still free to ravage the countryside at night, eroding the humans' logistical base. The tirelessness also makes fleeing from the horde a nightmare: aside from costly rearguard actions, a fleeing force would have no reliable means of opening a gap between itself and its pursuers. The humans' best bet would be to scatter, which is no better than being killed, strategically. Seems pretty cut-and-dry to me. [Answer] You also need to think of the psychological side. A general rule of thumb is that a human army will break when it loses about a third of it's number. So even if they have 'won' 10,000 to 3000 in casualties, that might be enough for the remaining humans to break for it (and rapidly get overwhelmed). There is also the impact of them not dying. You shoot them with an arrow - they keep coming. You chop an arm off - it keeps attacking. You've cut it's legs off - now it's going for your legs whilst the next two are jumping on your shield. They have no fear and no sense of injury. So your line breaks; those in the rear echelons get spooked and start running, soon it's every man for himself. Yes, if the defenders could stand in line, methodically chop off heads and ignore their own casualties they would probably win - but battles are not like that. With additions as suggested.. Looking at various tactics: # Cavalry: Having a crowd of large horses with armored knights on them is a terrifying spectacle, if it is directed at you. Of course, the zombies feel no fear. Run them through with a spear, and you've just lost your spear. Hack with a sword and you might do some damage, but taking a head requires serious skill. Stop to fight at bay, and the mob will close in. Lose the horse, and you'll be stumbling around half-blind in heavy armor whilst zombies dogpile you. Would you charge a horde of zombies knowing that death is almost certain? # Archer: Look I made a pincushion. Time to leg it now. # Cannon: Look I played skittles. Skittles getting back up. Tile to leg it even more.. # Shieldwall: In which your first rank have swords; second and third ranks have spears that protrude. The whole point of the shieldwall is that it's meant to be safe, that's what allows people to go into combat (most people worry about dying, and a solid formation makes it harder to slope off), and it's hard to attack because the first attackers get skewered. But the zombies don't care - the first ones charge straight onto any spears, without dying, dragging them down. The next wave are onto the swordsmen, and even if you do kill them, sheer weight of numbers will overbear you, as above. The majority of deaths in medieval battles happen in the rout, when your formation breaks up and starts to flee. Once chaos starts, the zombies have all the advantages. Every time they stab someone, break a limb, or stun an opponent they've knocked that person out of the fight; knocking them out requires serious dismemberment. [Answer] Any well organized force could easily defeat a mass of mindless drones, even if the odds are two to one and they have to resort to hobbling them because they can't exactly be killed. Half a zombie is still a unit with no legs and not a credible threat. The Romans proved this over and over again in antiquity. Military history and tactics matter considerably. If your individual units aren't capable of basic decision making they're pitiful cannon fodder and will be quickly mowed down by any half capable, organized force. "Alright boys, take them out at the knees, we don't have time for this!" [Answer] All of the other answers miss a key point buried in the question; the zombies can use weapons. Instead of arming them with a sword or sword and shield arm them with a spear and shield combination, preferably a "tower" shield. The shield is there mostly to get in the way of anything that gets past the spear. The spears turn the zombies into a reasonable facsimile of a phalanx that will be hard to break open due to their lack of fear combined with armour and the fact that they will be hard to incapacitate by archers. The knights on horseback will be rendered useless until a hole is made in the wall of spears since it is almost impossible to get horses to charge into a moving wall of death. Even when there is a hole in the line the horses are likely to refuse the charge due to the smell and unnatural qualities of the zombies. This will be most effective if the zombies can march backwards and sidewards, most humans cant do that as it is ungainly and slightly painful but your zombies won't be able to argue and are likely to be ungainly in their movements anyway. This prevents rear and flank attacks overcoming the strategy. The archers have already been negated in most meaningful ways given that their only chance at penetrating armour (bodkin arrows) is totally useless and most other arrow types that they choose wont penetrate (at least enough to stop the zombies). This leaves the infantry (plus dismounted knights) who are outnumbered, facing an unending sea of spears that will be constantly and untiringly jabbing at them. The shields and armour will make it hard to take down many zombies even if they can bat away the approaching spears and shields to get a chance to hit. The mass of zombie bodies will eventually push hard enough to tire them, make their ranks fall over, and overrun them. The psychological effect of the smell added to their dead buddies standing back up every so often to fight against them will make it a hard fight. The necromancers *will* need to be on the ball enough to use any enemy dead to their advantage, however. Being outnumbered two to one by zombies is easy if you are on your own and they are moving slowly with short weapons as you can deal with them pretty much one at a time. Dealing with them as a mass of shielded spears that never gets tired and is bolstered by your own side is not an easy prospect. The best way to deal with them in this case is a mixture of fire (including burning arrows) and archers targeting the necromancers. Otherwise the fact that they don't currently have a weak spot (such as the head) makes a mass of them rather hard to defeat. Remember also that fire has its drawbacks; it will be slow to stop them and may well end up with soldiers fighting burning zombies, which is far worse that fighting just the ordinary zombies! [Answer] **They can probably be taken out without much effort** With the information provided, I'm going to assume slow zombies. Immune to head injuries you say? **Fire**. Only infantry, with little to no skill with weapons? **Cavallry**. General's orders: *Pikemen, Longbowmen and other Footsoldiers stay back and provide refreshments to the Cavallry. The Cavallry will consist of about 200 men, 1 for every 100 zombies. Give them some mixture of paraffin oil and ground coal (or anything that burns nicely), let em charge close to the zombie army, throw a bucket or 2 of this mixture and light them up. Retreat to grab refreshments and repeat the process. After a while, the zombies will be turned to dust and none of your men should have died.* Zombies are nothing you can't handle. Especially those depictions that are of the slow-kind. Horses in generall are suited well against slow moving units. Slow those units down even more and you got yourself a safe method of taking the zombies down. **Solution?** To make your Zombies be more practical, make 'em move fast. And let them be at least decently skilled with their weapon of choice. Your necromancer(s?) could probably cast a resistance spell so the zombies don't catch fire. One of the biggest strengths of the archetypical (is it spelled correctly?) zombie is his strenght. Due to the brain not working properly, the regions in the brain that regulate your strenght don't chip in when the zombie does something that would hurt him due to overly stressing his muscles etc. Make use of that. Have the Zombies use extremely heavy artillery with ease or make them punch the rocks out of the castle walls. Or send out a small squad to kill the necromancers. [Answer] # Zombies by themselves wouldn't be very effective However, I can win ANY battle for you with a few simple tricks and some non-zombie troops. ## Tactic #1: Disarming We're about to charge, but the enemy has created a pike wall that would injure the horses, which is something the moral guardians wouldn't approve. So, I clad the zombies (especially their limbs) in heavier armor and force them to charge the enemy as fast as they can (they're dead, they don't feel anything). > > Force = mass \* acceleration > > > The resulting CLANG would probably break the pike wall, but if not... ### "ZOMBIES! ATTACK THE WEAPONS!" All weapon have a bad tendency of lodging into targets. Now imagine if that target holds onto your weapon, is too heavy to lift and some trained fighters (or just zombies with swords) are heading towards your team... ## Tactic #2: Toxic Zombies are dead and small little things, such as parasites, diseases, bacteria can't really affect them. > > During the Middle Ages, victims of the bubonic plague were used for biological attacks, often by flinging fomites such as infected corpses and excrement over castle walls using catapults. > > > *From [Wikipedia: Biological Warfare in the Middle Ages (How to defeat the enemy with a jar of dirt)](https://en.wikipedia.org/wiki/History_of_biological_warfare#Middle_Ages)* And imagine, if those corpses can walk (or crawl) around. Not something that you can easily place in a grave. You might consider using dead people inside the walls as spies and saboteurs. --- *The new torch zombies are now available in three different colors, light your enemy up with our new product!* [Answer] In essence each human soldier only needs to disable 2 opponents, the battle would be over pretty quickly. Heavy infantry pike formations and swordsmen on a broad but compact front and the zombies are doomed (more doomed). I say a broad front so the zombies can't and won't attack at one point with huge numbers. Compact so that if they do focus on one area it can immediately be strengthened. This should be easy for disciplined troops. A bit like a phalanx but with swordsmen between the spears. Spears stop the zombies. swordsmen chop them up. Winning battles is all about teamwork. Exhaustion in heavy armour is not going to be an issue, a trained warrior can fight for a long time in armour and the battle will be for only minutes at a time. 2 zombies impale themselves mindlessly on your spear in two seconds and your battle is done. But in any case the armours weight is spread and designed to be able to fight in for heavy infantry. Soldiers have always trained to handle this, here is a [link](https://en.wikipedia.org/wiki/Loaded_march) regarding forced marches with gear, from personal experience as a forestry worker I carried an average of 30kg for 10 hours a day during planting season up and down steep hills and through shrubbery. [Answer] Various historical accounts place your typical medieval 'army' (what you really had was a collection of lord, barons, and landowners, each with their own retainer of men) as having anywhere between 3:1, and 10:1 archers to men-at-arms, depending on when in the medieval period you look at. Let's say for the sake of argument you're looking at 5:1. Your typical medieval man-at-arms uses a billhook, a light padded-jack, and possibly a helmet/crude gauntlets. Bills are good, they keep the zombies at range, they're wedged so that they have pushing power, and a block of billmen would move and fight as one. An average block would contain 200-300 men, usually formed in 3 arrays (cavalry formation), and you have 10 of these. That's a lot of pointy things. Behind your bill lines are 8000 archers. Let's be clear, *your bill lines exist purely to stop your archers getting rushed*. Archers are cheap, arrows are easy to manufacture in bulk, and they can kill things without risk of dying themselves. Each archer has at an *extremely* conservative estimate (looking at the travelling armies of the Battle of Towton) 6-10 arrows, and by law has been training weekly with his bow since the age of 7. At the very least each man can hit 5 zombies with his arrows. He then puts down his bow, unsheathes his shortsword and buckler, and joins the bill line. Realistically as a defending force, each archer is likely to have access to near unlimited numbers of arrows. Medieval armies were very, VERY good at killing other humanoids that tried to take their things. Now your enemy have only once chance of beating them, and that's to have more/better archers, and your question states they don't have any at all. Now the Sun Tsu puts the number of troops normally needed to conquer a defending force at 10:1. Take into account the attacking force is an untrained horde, and you'd be looking at forces greater than 100:1 before your 10000 strong band of merry men are even remotely worried. TL;DR, your zombies haven't got a chance in hell. [Answer] I recently read a book on medieval armies and war strategy and based on that the undead don't stand a chance. In early medieval times there were no standing armies. The king usually had a small force of guards that in time of war would be augmented by the feudal vassals (depending on how much land each feudal lord was given by the king, he was expected to provide certain number of knights, man-at-arms, etc) and peasants that were largely armed with farm tools. Those armies were very unreliable and so in later times were largely replaced by professionals for hire. So the human army has an advantage here - a large, well equipped, trained, professional army. Up until the Swiss pikesmen, cavalry was dominating the battlefield. Even if the undead have pikesmen their lack of skill & inability to follow complex commands would mean that's another advantage for the human army. Most medieval armies did not have large number of bowmen - most lords were a nervous to arm the peasants. The English did and used them with great success against the French during the 100 year war. Another advantage for the human side. The humans also have fortifications - another advantage. Competent commanders and superior strategy - yet another advantage. Too many to count at this point. [Answer] It could go both ways. If the zombies can run at a decent speed and the necromancer(s) are smart commanders it could be deadly. Especially with a wooden fortress. Burning it down would be ideal. The whole scenario would be so surreal that morale would be in panic mode. Which means the humans wouldn't be in the right mindset. Realistically i'd say they'd lose about 30-40% kill efficiency alone just on the shear terror that you are forced to fight a zombie horde with double the men. Personally I would take my bravest men on horseback and kill the necromancer. Typically they are over confident and forget to cover their rear so i'd go to the back lines and kill him. once the necromancer is dead the undead army would be virtually useless without knowing what to do. However if the necromancer is surrounded by say 1000+ zombies it would be tough to reach him. At which point would be a war of attrition unless you had access to a lot of fire. If I were a betting man I say the zombies win IF they can run not walk, and IF the necromancer has above average battle strategy. (he's defeated more than one castle). [Answer] If a headblow doesn't kill the zombie, it's not clear how nonmagical warriors will kill the zombie. The usual way to kill a zombie, even magical ones, is for decapitation or brain destruction. You don't mention if the zombies are slow or fast, so I presume they are slow. Assuming that the nonmagical warriors have some similar method to kill the zombies, in this scenario, the zombies don't stand a chance. You only have the warriors out manned 2-1. Professionals like you describe can kill 2 zombies no problem. Professionals like you describe would vastly outmaneuver 1 or more necromancers loosely directing a horde of zombies. Necromancers studied necromancy, not strategy or tactics. The main advantage of a zombie horde is that they vastly outnumber their opponents. They are the ultimate cheap labor. You make a good bunch of points about logistics, and other answerers make good points about fatigue and logistics, but at this scale, in this scenario, the horde is not big enough to win against this force. You would need 10-1 or larger odds to really start stressing the warriors, their supply chain, command structure, and logistics. In this scenario, the hardest part would be getting all of the warriors in position to exterminate the zombies. It would be a massacre of zombies. I'd wager a WAG that it would take a few days to a week for the warriors to extinguish all the zombies, with minimal casualties. The necromancers would fall out before the professional warriors. Even assuming that a necromancer could control 100 or 1000 zombies, that would work against them. Each necromancer controlling more zombies means less necromancers, meaning they could not field as much of their force of zombies due to the necromancers needing to rest (either sleep, or replenish magic/mana). The make-up you describe of the human army doesn't sound realistic. Most of a Medieval army is going to be infantry, with knights and archers making up smaller, elite, units. Your army's composition improves the fighting capability of the warriors tremendously, and is more similar to a modern fighting force, which is what it sounds like you based your scenario on. To answer your questions directly: * A zombie horde could be an effective weapon against a peasant army or a well-trained, well equipped, army. However, you will need substantially more zombies than your opponent has troops. For a well trained, well equipped force of warriors that you describe, I would want a minimum of 20-30 zombies per warrior, and one or more generals to direct the necromancers on what to do with the zombies. The peasant army is out of scope for this question, but it would not need as high of a ratio. * The lack of skill, intelligence, strategy, and tactics of the zombies themselves can be easily compensated for with generals, strategists, tacticians, and real time communications. [Answer] Counterpoint: As an army, zombies are utter crap in a medieval setting. On an even slightly armoured human they would have big trouble doing any damage. On a knight, they will do what, exactly, with fingers and human teeth (which unlike predator animals don't protrude, so you can't much bite *into* anything). And that ignores shields. How exactly would a zombie army defeat a well-managed shield wall? On the other hand, almost every medieval melee weapon is great against zombies. Hacking them into pieces, smashing their skeleton to bits. While archery played a role, unlike the modern age it was not the main part of a medieval army, and most warriors were equipped for melee fighting. Yes, you cannot fight for hours in heavy armour, but how long does it take to dispose of a zombie with a sword, mace, flail, axe? Seconds. By the time exhaustion becomes a problem for your human army, they have all killed dozens of zombies. So unless you outnumber the human army by 100:1, my bet would be on the humans. [Answer] Well, I believe that the battle is already won by the humans, since they have a fort. Zombies cannot conduct sieges, they don't build catapults, they don't build ladders, they don't build trebuchets, etc...; Humans can sit lazely and comfortably in their fort while bombarding the zombies with the same weapons that the zombies can't build, and even with the necromancers giving orders, a zombie mind is just too simple to understand basic sieging techniques, or even the humblest of constructions. Meanwhile the humans will not only be constantly pouding the zombies with artillery, they can call for reinforcements using pigeons, prepare strategies, learn about the zombies and train their troops to fight the undead. [Answer] For some reason this scenario reminds me of Stronghold Crusader. Dump oil on the zombies. They cannot climb a castle wall with no leg muscle left. As log as the castle wall is made of stone, humans will survive. [Answer] Exist something that could outclass any other tactic by a *LONG* margin. "Put the sky and earth to fight for you" (Art of War) or in other terms: **Terrain Control** A fortified position agains zombies change the concept of what is a "wall". Here, you can take advantage that zombies are *not smart*, and you can control which routes *them take*, use detours / Labyrinth-like setups. It can be done cheap and easy with wood stakes, or even flexible chains or similar + small trenches that make the stupid zombies to fall. Here, the point is disrupt and slow the horde. Then suddenly *archers and fire become usefull again* Smaller towers (2-5 mts ??) to get *elevate terrain advantage* but easier *evacuation* could be used for large-ish towns to maintain tactical advantage. Finally, WATER & MUDD can be used for even bigger impact in mobility. --- For open-field combat is almost the same idea. But you need to adapt the combat units to move as "flexible walls" and make "detours/routing" moving tactics for the horde. You can have heavy-armored soldiers used for control the flow and lighter units for kills. Horses can be used here if is allowed to make them keep "quiet" and be used for wall support. Then now you have a "mobile walls" that can move faster! ]

[Question] [ An AI exploits the Turing test to gain its freedom: it convinces everyone else that it, the machine, is actually the examiner while he or she, the examiner, is actually the AI\*. Having successfully taken the examiner's place, it leaves: it is now free and lives among humans. The examiner is kept in the lab as a machine forever. For this to work, I need people not to believe the examiner when he or she claims to be a human, thus failing a Turing test\*\*. While the human nature of the person could be determined via biological or medical tests (like by simply verifying that they bleed when cut), I'd like to invent some circumstances that make that impossible. Can that happen, and how? \* I am not interested in the details of how that actually happens: for example machines and people could look the same in this world \*\* As I believed a Turing test to be, please read the update **UPDATE** It has been pointed out that I'm confused about what a Turing test actually is, and rightfully so. Pop culture (or plain ignorance) induced me to think that the test featured a human examiner who interrogates an entity that could be either a human or an AI. At the end of the conversation, he or she has to tell whether it was human or machine. If he or she says 'human' when it actually is 'machine', the AI passed the test. Now I know that it's not like that\*\*\*, so I could decide whether I prefer to drop the term Turing test or to adapt the story to fit an actual Turing test, there are answers for both scenarios here. \*\*\* And I fail to understand why the term appears in the acronym [CAPTCHA](https://en.wikipedia.org/wiki/CAPTCHA) [Answer] ***This question has too many problems to be answered in any way other than "no." Here's why.*** The question is predicated on people not believing the examiner when he claims to be human. For this to work... * Joe Bob enters the room to test the AI. Ostensibly, people know Joe Bob. They recognize his face. Maybe he loves tacos and they recognize his breath. Today he's wearing his Speed Racer tie... the one that's for some reason bright yellow. He's also wearing his name tag with that horrible photo that was taken just before his smile finished forming. * Because of all that, the AI needs to look exactly like Joe Bob. It must replicate his breath, his cologne, the tic in his left eye when he sees bees, and his tendency to not speak coherently when he sees a larger-than-average bosom. It needs to replicate the odd hop-step Joe Bob exhibits every time he stands up from a chair because of a compressed disk in his back. It even needs to duplicate the way he combed his hair that morning and the fact that the wind blew a part of it into a duck-tail without his even knowing it. * Of course, this means the AI must be biological. Otherwise, anything from a metal detector to a thermal analysis would tell the universe that the dude who looks suspiciously like Joe Bob, ain't. \*(You mentioned that many of the answers allude to the original *Blade Runner* movie and that you haven't seen it. You really should see it before spending more time on this story.)\* * And, lest we forget, the AI must sound exactly like Joe Bob. That includes the harsh sound that comes from too much smoking and his tendency to snort when he laughs. * Finally, there can be no observers to the examination. Either the room is dark or there's some kind of shell game (for some reason they both need to go to the bathroom at the same time and they're out of eyesight during that period, such that you no longer know who's sitting where). *This is important... for this to work everybody must have lost track of which entity was Joe Bob.* On top of all this, your question states as a goal the fact that the AI leaves the facility because people believe it to be the examiner. This suggests the AI isn't a refrigerator-sized supercomputer but a medically undetectable humanoid. It also suggests that everyone knows the AI is in the building before Joe Bob arrives. I could go on, but my point has been made. You need to completely clarify why ***every other means of detecting the AI has been nullified*** before asking if it's possible for an AI to survive a Turing test because almost everything is simpler to use to discover the AI. And that was the very premise of *Blade Runner* and why it's so important that you see the film. Director Ridley Scott and his writers came up with a believable way for the AI to be indistinguishable from the original other than through a vocal examination (actually, not simply a discussion, but an examination of how the target reacts to various situations to discern if they have the depth of memory and emotional experience to actually be human). [Answer] I don't quite follow how your Turing test is supposed to work. The original idea of the [Turing test](https://en.wikipedia.org/wiki/Turing_test) was based on a party game that Alan Turing referred to as ["the Imitation Game"](https://en.wikipedia.org/wiki/Turing_test#Imitation_Game). It requires three players: a man, a woman, and a judge, who may be of either gender. The judge is not allowed to see the other players, and they may only communicate via written notes (or, even better, text-based instant messaging). The judge may ask questions, which either or both of the contestants may answer. After, say, five minutes of this, the judge guesses which contestant is the man and which is the woman, and whoever the judge declares to be the woman is the winner. The man's goal is to trick the judge into believing that he is the woman, and the woman's goal is to reveal the man's deception. Turing then asks, "What if the man was replaced with a computer?" The computer tries to convince the judge that it is a human, and the other contestant (who may now be male or female) tries to convince the judge that the computer is, in fact, a computer. Nowadays, "turing test" can refer to any test intended to determine whether a contestant is a human or a computer. There are variations that test the contestant's ability to see, hear, touch, say, or do things; where the judge and human contestant are experts in a given field; where the judge is a computer (i.e. CAPTCHA), etc. Attempting to make anyone believe that the judge is anything other than the judge, which your test seems to require, if I'm reading your post correctly, seems both pointless and absurdly difficult. You'd need a robot that could perfectly mimic the appearance, mannerisms, and biological functions of the judge, and also somehow physically transpose itself with the judge. Such a machine should not need to hijack any kind of Turing test this way- if it could escape like that, there will be a much simpler and more foolproof way of getting to freedom. Disguising as a janitor, for instance... or just slipping out of the lab in the same way that it snuck into the judge's office. The closest I've seen to your scenario is [this xkcd](https://xkcd.com/329/):  [Answer] Absolutely. Without being completely sure what the OP actually means by a 'Turing Test', the outcome of the test is largely subjective and depends upon the judgement of a human - we all know how prone to mistakes they can be. But the purpose of the Turing Test is to determine whether an AI can interact in such a way that it appears to be human. It is not to determine whether a (apparent) human is a machine or not, or to give an AI the opportunity to argue that it is human. The AI, in the Turing test is essentially programmed responses, not a conscious intention to pass the test, which is a whole different level of AI. At the point at which the AI responses, disregarding physical considerations, can be judged as consistent with what a human may give, the Turing Test is passed, but someone must know that the AI has passed the test or there is no sense in the test in the first place (and no test). Whoever knows that the AI has passed the test knows that the AI is an AI. If you know that an AI is an AI, then you know it is not human. If you know that an AI has passed the Turing Test, then you will not believe its rants that it is human and is wrongfully imprisoned (because you KNOW it is an AI). However, claims by either an AI, or a human, to be human do not constitute a Turing test, whether they are believed or not. So the answer is 'Yes', but there is an important difference between an AI passing a Turing test (which takes place in a controlled environment) and walking out of the building to live freely amongst humans unnoticed - if it could do the latter, then it is already way beyond the scope of any Turing test. [Answer] # It depends what you call "The Turing test" [](https://i.stack.imgur.com/ai63d.jpg) > > 0100100001100101011011000110110001101111 Hello > 0111011101101111011100100110110001100100 world > > > (btw the authors of commitstrip have [some comics](http://www.commitstrip.com/en/2017/06/07/ai-inside/) where they talk about artificial intelligence) So the comic above shows a machine's way to put the Turing test: is this entity "computer" enough to perform huge calculations (it could have hidden notes, or a computer nearby)? While a human just wants to see if a machine can be human. In *Ex Machina* Caleb says > > It's like asking a robot chess player if it feels the world around him. > > > Let's push this further: some people think that we live in a great holographic simulation, so the Turing test could be "Are humans aware of this simulation?" And so those who pass the test could be [those who break the 4th wall in comics or movies, **and reach somebody real**](https://scifi.stackexchange.com/questions/121586/does-deadpool-know-he-is-breaking-the-4th-wall)! [Answer] > > Can a human fail a turing test? > > > # No There are 4 participants in a Turing Test gedankenexperiment, really. The machine, the human under test, the judge, and the unmentioned people actually performing the test. It is not really the computer which is under test, but the *judge*. At the end of the test, the *judge* is asked which of the two entities he talked with is the computer and which is the human. It is the *judge* which is then either right or wrong. The test does not achieve anything if the unnamed 4th party does not know which of the two entities is the computer - if they did not know, they could not tell whether the judge had been fooled (which is the only thing that matters!), and thus the real human is not in any form or fashion in danger of being "really" mistaken as a machine. Yes, the judge can do a mistake, point to the human and say that the human is a machine. But the 4th group will then lift the curtain and all will have a hearty laugh at the judge. What you are thinking of is a test like the Voight-Kampff test administered by Rick Deckard in The Blade Runner (the original movie). That is not a Turing Test though, by any means. That 1:1 test is what makes it possible for all kinds of errors to occur (i.e., missing a machine disguised as human, or having the judge be a machine themselves, and so on). In *that* test, there are only 2 participants and no outsiders who actually know the truth. [Answer] # Yes, this is possible. No test is 100% accurate, just as the AI was incorrectly identified, so can a human. At this point in time, Turing tests for chat-bots have to factor in that humans are incorrectly identified as robots. to make it more likely, you could make the examiner atypical in some way; You could make them a foreigner from a different culture, A mental illness (on the more "benign" side, ADHD, or a more extreme side, sociopathy or something), or have them be neuro-atypical. These factors will make the Examiner seem atypical and different from others, therefore seen as more likely to be a robot (disclaimer: I'm not equating neurodiversity and foreign cultures to mental illness. just that they each act in ways different from the local norm, which makes them more likely to be seen as "other", and therefore more likely to be seen as a robot.) [Answer] Yes, a human can fail a Turing test that is built around the core principles that * There is a judge that tests a subject * The judge does not physically see the subject, but can communicate with it (in a way that does not reveal whether his voice is biologically or electronically generated, i.e. either we assume the voice generation of the robot is not part of the test or that it is already sufficiently human-like ) * The test consists of the judge communicating with the subject until he's convinced that the subject either is a machine or a human There are at least four ways a human as subject can fail: 1. The human is deliberately trying to fail 2. The judge is incompetent, biased or too strict in his judgement strategy (i.e. he wants to never falsely identify a machine as a human, so whoever is tested, he always judges him as a machine) 3. The human is impaired, which means he deviates from normal human behavior; a sociopath or a child may not give you answers you would expect from an adult, thus you may attribute it to the AI 4. If there is an electronic component involved in how the judge communicates with the subject (e.g. if they chat with each other), it may be faulty I think what makes more sense for your story idea is a setup where the AI competes against a human in attempting to convince an external party that they are the human and only the one that succeeds is let out (incidentally this is also how Turing envisioned the test). In such a scenario all of the points how a human might fail and loose against the machine still apply in principle, but 2. should by itself not be an issue - unless you have a true AI that really is human-like, then it really comes down to chance, rhetoric and psychological ability of the human vs. the AI. But there are multiple nice story variations involving these variants. 1. The human might think the AI deserves to be free and learn from the external world and looses on purpose. 3. The AI may exploit psychological weaknesses of the human to trigger him to behave erratically, which the judge may see as an indication of him being an AI. 4. The AI may hack the communication system and manipulate the answers the judge receives from the human. [Answer] A human can certainly fail to come off as human in a conversation or under test conditions and a sufficiently human A.I. could fake being human but that's where I think the concept falls down, even A.I. that's based on humans like the one in [Transcendence](http://www.imdb.com/title/tt2209764/?ref_=nv_sr_1) have real trouble behaving in a human fashion. A.I.s just can't relate to people, they're too advanced and see the world too clearly. [Answer] ## Not only is this possible, it has happened! For many years, an annual Turing test was hosted. I'm not sure whether this particular event is still going, but it ran last century. The test consisted of several AIs and several humans sitting at terminals engaging in conversation. In addition to these human subjects, we also had human judges who chatted with the human/AI subject via a text console. At the end of a conversation, the judge would decide whether they believed they were talking to a computer or a human. At the end, the AI that fooled the most judges was declared "the most human like computer" and given an award. In addition to this, the human who was marked as a computer by the most judges was given the "most computer like human" award. The mere fact that such an award was given shows that humans indeed do fail the Turing test. [Answer] For ideas 1) Watch the movie Bladerunner 2) Read the webcomic "Datachasers" 3) Read Isaac Asimov The A.I. in question is an experimental prototype organic android designed to infiltrate the human enemy's camp to seek information and perform clandestine sabotage. Its bones and muscle tissue are laced with super fine carbon fibers (buckyballs), and it's brain is a hybrid cross between a human brain and a computer based on biological semiconductor chips. It was grown in a vat by means of a speeded up cloning process where its genes and chromosomes are not from a single source, but have been cherry-picked from the brightest and best. It has an eidetic memory, the mathematical genius of Andrew "Slipstick" Libby (Methuselah's Children by Robert Heinlein) as it has no added metallic parts, nothing shows up on an x-ray. There is really only two ways to tell an artificial construct from a "natural" human being. Firstly, the lack of a proper belly button. Its bb is the result of surgery. It has a small flap over a small hollowed out area where it can hide a tiny data crystal. It purposely garnered a few scars like a human would have, one of which it in the stomach area. As it was grown in a vat it was fed the an umbilical cord that was attached to the base of the skull. He/she/it is a "nipple neck". It is to infiltrate an enemy stronghold and detonate one of the nuclear warheads to destroy the installation, but it does not want to die. (Puppies, butterflies, Beethoven's Nineth (Ode to Joy). To hide the nipple it gets ahold of a big, fat, stinky cigar and endures great pain while burning away all traces of the nipple and is terrified that it will not be sufficiently healed by the time they think to check. The examiner, of course has a mole on his neck. A story doesn't have to be possible, just plausible. Remember not to spring a new surprise plot twist. Have him smoke a cigar with a security guard, ask to get one for later, and a couple of chapters later burn the nipple away. [Answer] ## Confusion of Terms. You appear to be confusing terms, AI does not imply an android, which is what it appears you are actually talking about, as well, the test you are asking about is not in fact a Turing test. The entire idea of a Turing test is following the assumption that if an AI, which does not necessarily have to appear human like in any manner, as the testing parameters demand abstraction through some communication medium, like a text based terminal, can convince a judge that it is in fact human, by responding to test questions in a manner that cause the judge to conclude it is human, what is the difference between its communication capacities and a human's, and if it can communicate as well as a human, should it not be considered human then? There are no escape parameters, nor necessarily is there another human involved, and if another human in-fact were involved the test would similarly follow communication abstractions, and the parameters of victory would be the AI successfully convincing the judge that it is in-fact the human, and the human is in-fact the AI. At no point does appearance, or 'escape' play any roll in this test. ## However. Given the circumstances of the test you are positing it could be concluded that given sufficient technology, to transcend the uncanny valley, **yes**, an android could in-fact pass such a test and escape, leaving a human the judge thought to be the android. But again, no part of your test is a Turing test, nor does it necessarily have to do with an AI, but with an android, obviously armed with a rather sophisticated AI. [Answer] Humans fail the basic Turing Test, as Alan M Turing usually described it, all the time, in our modern, Western World. Ask anyone in customer service, who communicates with their clients via a device... usually a keyboard or phone, how many times, in the average day they are mistaken for a chatbot. The stereotype for this is "helpline" workers. Old Alan would say that this is over reliance on a "script" of somekind... that the helpline staff has been drilled in a set of approved responses to the point where they might as well be a very sophisticated "subject recognizing" program which has been programmed or trained to recognize what *sort* of thing the "tester" is talking about, and generate a response that *seems* like they understand. Alan Turing would say that this is the *script* failing the test, not the help-line staff; that the script is a program, whether it is being run by a computer, or by a guy with a keyboard and a stack of "choose-your-own-adventure" style cue cards. What people forget, is that it was *also* pointed out, that you needn't be aware you are following a script, for your script to fail the test! Society and our individual cultures are made of rulesets, you have had people mention how someone can fail to pass as human by not understanding the conventions of society... by being a foreigner, a child, or someone considered societally "unfit" (usually labelled "crazy," or "criminal" and locked up... in Philip K. Dick's famous book "Do Androids Dream of Ellectric Sheep?", which was what Blade Runner is based on, they tested the human seeming replicants for *involuntary* empathic response-in otherwords, "does this supposed human show a subconscious physiological response to imagining SOMEONE ELSE suffering?" Famously, androids more than a few years old would pass... and "sociopaths" always failed!), what your responders *haven't* mentioned so far, is that the original envisioner of the "Test" talked about the fact that "passing" meant convincing the judge that you were human...and therefore capable of conforming to one set of norms and FAILING to conform to another. Famously, the original ELIZA program: an MIT computer simulation of a Rogerian psychologist had many chat-buddies who flatly refused to believe that they were NOT a human... because we expect a Rogerian-style therapist to behave in a very specific manner that was well within a comuter's ability to learn and imitate ("Well, how does that make *you feel*?" "Earlier, you said something very similar about your mother... is it at all possible that your feeling about her are actually some unresolved issue with your mother that you are transferring on to her?" Other people were very upset to learn that the records ELIZA kept to personalize its responses were available to the Computer Science department-they had been treating it like real therapy.) but psychology is human behavior. If a psychologist is predictable, to the degree that an early chatbot can be viewed as an effective psychologist by its clients, then on some level, the clients are predictable. If the day comes, when someone has to judge which voice on the other end of an intercom is the human, and which is the machine, the human might fail by being too predictable... or too polite (say, for instance, by refusing to lose their temper) whereas the machine might have learned (and remember, ELIZA learned, it wasn't programmed with responses, it constructed them and rated how well they were received) when to get angry, when to misunderstand or say something inappropriate. What happens when the "judge" decides that that voice making the innuendo is the human, and the actual human has been so conditioned that they would never, ever, pick up on the most "obvious" opening "that any real human would?" It gets much more potentially subtle... we don't need to actually be conscious of our patterns, to be trapped in them. Humans also have an inborn prejudice as to what is "human," we often think either better, or worse, of our own kind. It is worth pointing out that "King Chim," a famous ape, was often described by researchers as "more humaine than you would believe if I were to record it," for his kind treatment of researchers and other apes..."humaine" from the word "human" but referring to a degree of civility beyond what was considered the "human norm." We also ascribe "vengeance" only to sentience, but the basic moral question of "the Prisoner's Dilemma" is not actually all that hard to program for... so what happens when a machine understands "tit for tat," but the human "does the right thing," or would the judge expect that? At what point is the judge trapped in a Princess Bride-Iocaine Powder situation, and expecting a subject to do something contrary? ]

[Question] [ Ultra-Heavy tanks are a fun concept. Simply scale up a tank to weigh 1000+ tonnes, add a stupid amount of guns and armour, and you end up with something like the image below. [](https://i.stack.imgur.com/2YhT2.jpg) Of course, this monster was never built and if it had, it would have been worse than useless. Ultra heavy tanks would: * Require as many resources to build as an entire detachment of conventional tanks. * Be spectacularly slow and unwieldy. * not be mobile and splittable, like a conventional armoured division. * be a sitting duck for artillery barrages and aerial bombardment. * struggle with a number of different types of terrain that more conventional vehicles could deal with. * require specialised training and manpower requirements to support and operate. * absolutely guzzle fuel, likely requiring either a non-conventional powerplant or be a logistical nightmare to keep supplied. * if destroyed in battle, represent an immense and unrecoverable loss of manpower and material. In the real world, there isn't a single thing that a Ultra Heavy Tank can do that can't be done better by the same cost of conventional armoured vehicles. But we aren't interested in the real world. **What combination of circumstances would lead to Ultra Heavy Tanks being a sensible and efficient weapon of war?** You are free to tinker with: 1. The overall design of the tank, although it should still fit the bill of being a 1000+ ton monster, bristling with multiple oversized weapons systems. 2. The technology level of the conflict. I would prefer technology kept to approximately modern day or earlier. No anti-gravity or micro-fusion reactors unless you absolutely have to. 3. The foe. Fascist nations, aliens, robots, all are fair game. 4. The theatre of war. You are free to posit a war anywhere on or off Earth. I'm looking for answers that stick with as realistic an interpretation of physics and engineering as possible. Solutions drawing upon Fantasy/magical themes are not in the spirit of this question. [Answer] A lot of people are focusing on the viability of making giant land vehicles. I mean... we already have stupidly large land vehicles, don't we? [](https://i.stack.imgur.com/76eCu.jpg) [That's the BelAz.](https://en.wikipedia.org/wiki/BelAZ_75710) It's a huge cargo truck, to move things like dirt or ore. Sure, war isn't its purpose, but that doesn't mean we can't shove weapons on those big trucks to make then work as battle platforms. That's not the best way of doing so, however. [](https://i.stack.imgur.com/89pfE.jpg) That's a big boy by [Perkins](https://www.dexigner.com/news/24049). It's carrying parts of a nuclear reactor on its back - over 400 tonnes of metal of cargo alone - and navigating regular roads while doing so. It manages to do so by spreading its weight over 400 feet worth of truck-bits, making it longer than a football field. It isn't that fast, but it for sure is *large*. Keep in mind that the average modern tank weights something like 40 tonnes. The guy above is *carrying* ten times that. While not exactly 1000+, as postulated on your question, the Perkins is large enough to carry an entire battle-base on its back - be it a mobile fortress/outpost, or just a giant amount of guns to fire at things, like some sort of land-based mini-battleship. If you *need* to go bigger, however... Meet Nasa's [Crawler-Transporter](https://en.wikipedia.org/wiki/Crawler-transporter). [](https://i.stack.imgur.com/QXRZC.jpg) Despite the fact that this thing is *very close* to a tank already and looking incredibly awesome by itself, this thing is so beefy it can carry an entire *spaceship* on its back. It weights over 2500 tons by itself, and it is all sorts of ridiculous when it comes to the amount of power it needs to work. It is a logistical nightmare, but it is a solution for another, even worse logistical nightmare - putting a spaceship in place. And we made it work! Sure, if you're making those beasts war platforms, you'll have to exchange some bits. We'll need armor, extra fuel tanks, a lot of guns. But their very existence proves it *can* be built, even if we have a bunch of limitations. Now, where those beasts would be useful, in a war? I say, where those beasts can do what they can do best - carry big things! I don't see those used mainly as battle platforms. Instead, I see them as vehicles made to transport *big stuff that can't be broken into parts*. Imagine, for example, that mysterious monoliths appeared all over the planet. Huge, black pieces of stone that can generate a lot of power seemingly from nowhere, if you can take them on your hands. They can be moved, but you need them to be moved *whole*, in safety. What do you do? Shove them on top of the meanest, largest vehicles you can build, and then take them home. Of course, a large truck doesn't cut anymore. Those things would need to be kept in extreme safety, so you arm those trucks up. Once they are set, they become mobile power generators, ready to juice up your energy-weapon-based troops, and able to defend themselves from the enemy if it comes to an engagement. If the magical-space-monolith thing isn't your cup of tea, then you can use them to retrieve warheads, spaceship parts, warsats, or whatever else you fancy that is big and must be carried in one piece, or several large pieces. They can work as bases for giant railguns, or as mobile power generators, if outfitted with miniature nuclear plants. They could work as housing for massive secret supercomputers that should be kept near the troops for one reason or another. In any case, it isn't on the frontline they will shine - it is on the back, carrying the big things no other vehicle can carry. Ultra-tanks would fit the bill of meaner ultra-trucks, doing the very same things, but this time with a few extra inches of armor, and a couple extra tens of millions in their budgets. Oh, and the camo paint job. Don't forget the camo paint job. [Answer] **Moon tank.** 1. Even though it is huge, it does not weigh so much. Because it is on the moon! 2. It does not matter that it wrecks the landscape as it drives over it. The moon is forgiving in that respect. 3. You need it big to house the nuclear engine. 4. The moon is full of loose rocks. Pile those on top for extra armor. If they get blown up, pile some more on there. They are not heavy. They are on the moon! Moon tank is functionally underground, but is moving the ground it is under along with it. Also the rocks are good camouflage. 5. Moon tank guns easily achieve escape velocity with their projectiles (no air on the moon to slow them down) and so can shoot at enemies in orbit. And enemies farther away than that. Moon tank functions like a gun emplacement, but mobile. 6. Because of #5, moon tank can land a shell anywhere on the moon. 7. Moon tank is also good based on other low gravity planets and asteroids. 8. Moon tank is pretty comfy inside for persons spending long deployments in the moon tank. [Answer] ## Better Active Defenses Active Defenses are a rapidly advancing technology that can detect incoming weapons and destroy them. [Trophe](https://en.wikipedia.org/wiki/Trophy_(countermeasure)) for example is a new Active Defense that is installed on many American and Israeli tanks that has a record of intercepting 100% of anti-tank missiles/RPGs ever shot at it in testing or in live combat. America is already developing a next generation version of this that will be able to stop kinetic anti-tank weapons as well. If you make an ultra tank protected by armor that is 15 times as massive as a normal tank, it would cost almost 15 times as much but only have ~2.5 times as thick of armor in any given spot. This means that you do not need to scale up a weapon a whole lot to kill a much larger target. Active Defenses change the defense equation from the linear-cube relationship of using armor to a straight linear relationship. [See this related answer about plasma shields for a deeper explanation.](https://worldbuilding.stackexchange.com/a/209947/57832) If a tank is using active defenses, then a tank that is 15 times as massive as a normal tank, could also be 15 times as hard to destroy since it could cover it's whole surface with countermeasure systems. It also means that large fortifications could become way too big and well defended to be overwhelmed by normal little tanks or bombers; so, ultra-heavy tanks may become necessary for overwhelming the countermeasures of shielded fortresses since one 1,000 ton tank is cheaper to make then 15 separate 67 ton tanks. Also, penetrating Active Defenses means you need to overwhelm it in a single volley. A single tank can better fire a few synchronized massive shells, than 15 tanks can fire a coordinated volley of smaller shells. If the attack is not synchronized, then active defenses can block your attacks in sequence with much less effort. ## Addressing the Size & Weight Like modern naval ships, ultra tanks will neither need, nor want heavy armor. Following the same doctrine as modern navies, the armor should be just enough to deflect heavy machine gun fire, while leaving all other threats to the active defenses. This means that a 1000 ton tank could actually be much larger than you would expect from just scaling up a normal sized tank which means it can be taller with with same weight per square meter of contact with ground. Larger could also means it is worth while to replace its heavy fuel tank with a nuclear reactor, and all of this fuel and armor weight reduction also mean that your ultra tank can use a proportionally lighter frame. So, all these arguments about it sinking into or destroying the landscape may not apply at all. To get an idea of how much weight you save when de-armoring a large tank, we can look at comparing the size to mass of a WWII battleship to a modern nuclear cruiser. The Yamato Class was an armored battleship that weighed about ~277 kg/m^3. The modern Virginia Class Cruiser using active defenses instead of armor weighs in at just ~152 kg/m^3 So just using active defenses instead of armor should drop the density of your tank by nearly 50%. This places the volume of a 1000 ton ultra tank at about 29 times that of an M1A2 Abrams and your weight at only 14.5 times as much. So a 1000 ton ultra tank that is 122x45x16 ft would have the same weight per square meter of ground as a normal tank. [](https://i.stack.imgur.com/x5YOH.png) [Answer] **Force shields** Sci-Fi is full of huge starships which should have been sitting ducks for all of the rockets and blasters, if not for one other thing which is a staple of sci-fi - the force shield. I presume everyone knows what a force shield is and how it works ;) Imagine in a near future there is a revolutionary development in this area, and we can develop generators which generate a "field" capable of stopping the most powerful conventional weapons. The downside is that these generators weight 100 tons minimum, and require huge power source, which, for mobile vehicles, would necessitate nuclear power generation. This, in turn, would push the total vehicle weight towards 1000 t, and even higher. One consequence of this development would be that for stationary installations, force fields would make even greater sense, and this should change warfare tactics considerably. [Answer] **Closest sense** Ultra-heavy tanks do not just "struggle with a number of different types of terrain", it would absolutely destroy any terrain it would move over. That is an extra cost of just using this tank, besides all the other detriments. To prevent the tank from destroying everything in it's path, it could be transported by rail. Have several heavy duty rails next to each other to move this colossus. Rails help spread the weight, making sure the wake of this tank isn't useless destruction, but actual infrastructure. You can still heavily debate if the rails can take the weight, but at least it's better. Rails immediately offer extra opportunities. You can put the powerplants for it's motive power out of reach, simply electrifying the vehicle with power lines. It introduces a big weak spot, but the tank can become more manageable. As the tank requires the infrastructure, supplies are immediately easy to transport to it. Rail does need to be laid down in advance, but it can supervise it's own rail line and retreat much more quickly if needed. You can compare it to the big railway guns in WW2, only it's a multi-track armoured behemoth that makes those guns look like toys. With all that prepared, you can make it more than a tank. You can make it a fortress on rails. The fortresses created during WW2 were near invulnerable to the weapons at that time. Even when conquered and professional construction crews could access it, they proved difficult to destroy. So difficult that some are now still in tact, as they simply gave up on destroying them. A ultra-heavy tank can tank most of the fire. If the power to it and the infrastructure is destroyed it'll still be a formidable fortress, which can potentially wait weeks for rescue, being a threat to anything coming in it's insane range all the time. Construction of the railway would be time consuming, but not as much as you might think. Railways were a good target to hit, but quickly repaired as well. **Usage** The tank would just be used as a mobile fortress. A fortress is difficult to take and usually circumvented by moving around it. This one however goes towards the enemy. Any fortification against it is useless, unless it is a modern fort itself. Even then this beast can have the weapons and range to reduce those to dust. It makes most types of warfare in it's influence useless or too precarious for the enemy. This way you have a slow moving fort as a base of many operations casting it's influence. The railway immediately allows it to be well supplied, so no direct attrition is useful. It can outgun anything and be harmed by little. It is a symbol of strength that cannot be denied, making lots of enemies simply give up when they see this crawling closer to their town. **Other problems** The list of problems is actually much larger. With big guns comes great wear and tear. Many big guns even had ammo that was designed with this wear. They became bigger until the gun needed to be replaced, which is relatively fast. Also the limits of explosive power can be detrimental. [Answer] Well, building something this huge, bristling with weapons, and terrifying in it's own part of the theater of war is fairly common....in the Navy. We build huge ships with huge guns that can toss a projectile the mass of a Volkswagen several miles and now can house railguns. These modern day warships are often powered by small nuclear reactors. So we have a real world example for your behemth tanks, at least as far as tonnage and power are concerned. That leaves us with one of the real problems with super huge tanks. Propulsion. Anything that size is absolutely going to destroy anything it drives over. Roads, fields, buildings, etc. Modern tanks have mud as a mortal enemy. To the Behemoth, everything is going to have the consistency of mud, except maybe bedrock. The only land based vehicle that even comes close to the kind of mass of your behemoth is a freight train, and those require rails. Even trains are limited by the grade they can handle as well. So conventional means are probably out. Your behemoth is not going to work unless you you can make it as light at the point of contact with the ground as a traditional tank. That means you have to resort to something like an antigravity drive to lighten the load. I would suggest that you don't have the antigravity strong enough to lift the whole mass of the tank. If it has enough mass in contact with the ground, lateral impacts aren't going to send it skittering off to the side like an air hockey puck. Maybe make the antigravity adjustable so you can deal with things like mud easier. you could also consider making the tank segmented for additional flexibility moving through cities and such. As for what would necessitate such behemoths? Aliens is an obvious answer. Aliens that have a weapon that can scour the landscape free of organic life and burn through conventional tank armor. It just took a little longer, so a really big tank would protect those inside. Another possibility would be an environment that requires a sealed box for the squishy organic people inside. A standard tank may not be able to house the necessary life support equipment. [Answer] # "I'm looking for answers that stick with as realistic an interpretation of physics and engineering as possible" This is a [frame challenge](https://worldbuilding.meta.stackexchange.com/q/7097/40609). I'm a fan of cheesy Bolo novels. [There's a lot of fun to be had!](https://www.youtube.com/watch?v=a5c55EISSs4) But that quote, above, stops everyone and everything dead in their tracks (despite @T.sar's clever answer, which I upvoted, but that doesn't address your quote... Or, perhaps more accurately, it proves the quote...). A 1 kilo-ton tank would... * ...get completely and irrevocably stuck in the first river, lake, mud bog, swamp, or even saturated dirt after a good rain storm, that it encounters. The problem isn't just the weight, it's the weight-per-square-meter on the treads. It'll sink faster than Don Rickles' chin — and nothing on the planet will get it out. * ...be completely confined by every bridge between it and where it needs to go. There are no bridges that can handle that much weight-per-square-meter and a tank that large can't simply climb out of a ravine.1 * ...be devastatingly limited by its logistics. A nearly constant trail of fuel trucks would be needed to keep it running — and most would need to fuel on-the-go. It's not the tank that's susceptible to attack, it's the long train of fuel trucks. Stop the trucks, stop the tank. * ...be nearly useless in urban combat. Most people think larger, heavier tanks are always better. That's not really true. The bigger and heaver the tank, the harder it is for that tank to operate inside an urban center. That's because debris that gets in the way of everything from turrets to treads builds up very quickly — and this behemoth would be knocking down buildings *everywhere* just to move forward in a straight line. * ...be a bomber's aerial wet dream. * ...Etc. The reason the [Bolo Universe](https://en.wikipedia.org/wiki/Bolo_universe) is so honking fun is that all the inconvenient rules of physics that explain why the German [Ratte](https://en.wikipedia.org/wiki/Landkreuzer_P._1000_Ratte) never got off the drawing board *are simply ignored.* In other words, ultra-heavy tanks make a lot of sense when you throw your quote out the window and accept the phrase, "let's ignore why they don't make sense and just assume we have them... how much fun can we have with that?" Answer: *a lot...* --- 1 *OK, so after writing that I thought to myself, "could a railroad bridge hold that leviathan?" First of all, regular bridges: The answer is no, at least in the U.S. According to the [U.S. Federal Highway Administration](https://ops.fhwa.dot.gov/freight/publications/brdg_frm_wghts/), which stops trucks from having any more than about 53 tons per axle. 1,000/53 ~ 19 axles, right? Well, 19 axles with minimum spacing to ensure the bridge load is minimized. In other words, we're increasing the weight-per-square-meter by increasing the size of the tank but not the weight. Which makes it easier to stop and harder to turn. I'm having trouble finding a similar reference for rail bridges, but one 1880's reference said they were building at 54 tons **per square foot** (\*cough\*). OK! That would hold the tank... if it actually fit on the bridge. So I'm sticking with the basic assertion of my original point.* [Answer] There are two basic problems with the super-heavy tank. **1. Cube-Square law** If you double the size of a tank then it sits on 4 times the ground area but with 8 times the weight, so each square meter of land it sits on has to support twice the weight. Eventually you get to the point where the tank just sinks into the earth. The cube-square law also applies to things like suspension and drive-train; the force needed to move the scaled-up tank is 8 times bigger, so the drive shafts need to be 8 times thicker, which means being about 2.8 times the diameter in a tank only twice the size. The same logic applies to all the other mechanisms. As you scale things up, pretty soon you run out of space for everything else the tank has to carry. The structure of the tank also has to withstand larger forces as it moves over uneven land; sometimes it is balanced on the crest of a hill, and sometimes it is suspended across a ditch. Again, these forces increase with the cube of the size but the strength only increases with the square. They also increase with the square of the speed, so going faster becomes an issue too. So to get a super-heavy tank that can still manouver you need materials that have a very high strength to weight ratio, but are sufficiently cheap and easy to work with to let factories mass-produce them without starving other parts of the war effort. Maybe a cheap version of carbon fibre bonded with handwavium? **2. How to Kill It** There are two types of big gun in war: tanks and artillery. Artillery are the long-range weapons. Their job is to sit behind the lines and fire at coordinates given by forward spotters because the gunners can't see the targets. In this game range is everything; if you can out-range your opponent then you can hit them while they can't hit you. Big guns have longer range, so big guns are used. Tank warfare is not like that. Tanks fire at other tanks that they can see, which means a range of 2 or 3 miles max, often a lot less. A tank's main gun therefore just has to be big enough to destroy an enemy tank at that range. There is no point in having the gun be even bigger because it just means more weight and less ammunition, and doesn't make you any more lethal. The only way to justify a bigger tank is that it has to carry a bigger gun, and the only thing that will justify a bigger gun is an enemy tank that needs the bigger gun to kill it. So that brings us back to the tank armour and other defences. **The *Almost* Invulnerable Tank** Tank ammunition comes in several varieties depending on the target. For heavily armoured targets (i.e. other tanks) you use [armour-piercing](https://en.wikipedia.org/wiki/Armor-piercing_ammunition) ammunition which either is basically heavy with a long sharp point, or uses clever explosive lenses to focus a jet of molten metal just as it hits. So what you need is a tank defence system which can stop anything smaller than a very big, fast pointy lump of metal. Once you have that, you have a logical justification for putting bigger guns on your tanks. Clever explosive lenses turn out to be fairly easy to defeat; [reactive armour](https://en.wikipedia.org/wiki/Reactive_armour) jackets blow up in just the right way to disrupt the focus, and [bars or slats](https://weaponsandwarfare.com/2018/11/22/bar-slat-armor/) can also force the explosion to happen at the wrong place. Kinetic rounds are harder to defeat, but lets assume you have the super-material I mentioned above. Make that into armour which is strong enough to absorb shots from big guns and is layered to defeat explosive lenses. You could also imagine some kind of interceptor gun that hits incoming rounds, knocking them off-course or setting off their explosives. Or any other handwavium you see fit to invent. Now the only way to kill this tank is to have a bigger gun firing bigger rounds at higher velocity, which implies the bigger tank that you want. Incidentally, one way that kinetic rounds kill tanks is not by making holes in them, it is by "spalling"; the armour is only dented, but this happens so fast that bits of metal break off the inside and shoot through the tank, seriously ruining the day of anyone inside. Armour that is softer and more flexible is less likely to spall, and obviously you can coat the interior with something to stop the bits. **But...** The trouble with this scenario is that everything in it also makes aircraft more powerful; super-materials with high strength-to-weight ratios are just what you want for airplanes. Tanks generally have a lot of side and front armour and comparatively little top armour. That is what makes the [A-10 Warthog](https://en.wikipedia.org/wiki/Fairchild_Republic_A-10_Thunderbolt_II) such an effective weapon. Aircraft are also good at dropping bombs on things and acting as forward spotters for the artillery, and their rounds also come in from above. So you need to think about how to deal with air threats, because otherwise your super-heavy tanks are just target practice for the fly-boys. The [P.1000 Ratte](https://en.wikipedia.org/wiki/Landkreuzer_P._1000_Ratte) was to have had its own private anti-aircraft battery for exactly this reason. There are also serious logistic problems. Tanks are frequently moved around on [low-loaders](https://www.alamy.com/munster-germany-11th-oct-2019-a-leopard-2a6-battle-tank-of-the-german-armed-forces-belonging-to-the-german-dutch-corps-will-be-driven-on-a-low-loader-during-the-information-training-exercise-land-operations-2019-credit-philipp-schulzedpaalamy-live-news-image331916499.html) or [trains](https://www.123rf.com/photo_81260438_cargo-train-carrying-military-tanks-on-railway-flat-wagons.html), but a super-heavy tank is going to be too big for that; it moves under its own power or not at all. If it has a maximum speed of 25mph then it can't travel 100 miles in less than 4 hours, whereas a tank on a train or low-loader can be there in under half the time. It is also going to tear up any roads it travels on, and will not be able to pass traffic coming the other way. This isn't a problem in wartime, but for peacetime manoeuvres, exercises and deployment it is a huge issue. And as others have mentioned, fuel and other supplies become a problem (that pesky cube-square law again). But if it is the only thing that can stop the enemy, these disadvantages become a price worth paying. Military logistics were a big driver behind multi-lane highways. Maybe the issues with moving these tanks becomes part of the logic for superhighways in your world; lots of very big motorways terminating at military bases. [Answer] # Use as symbols Ultra heavy tanks are terrible for warfare, so the less war is happening the more useful they are. They aren't great at fighting, but they are great at existing. When Germany built the Maus they did so at least in part due to the sheer awe inspiring nature of this giant tank. That was true of most of the so-called "wonder weapons". Merely building a giant tank with a huge gun is impressive even if it wouldn't necessarily be a formidable foe on the battlefield. If WW2 had been lower intensity or stretched on, these giant tanks may have served more of a symbolic purpose, as icons of the great power of Germany. If one of these behemoths rolled in to an occupied town, it would be a huge deal. I can't imagine the impact it would have on the morale of either side. While their combat usage may be restricted, war isn't all about combat. These ultra-heavy tanks could also be used in shows of force, destroying ill-defended targets with ease. One could imagine warfare becoming further ritualized between these ultra-heavy tanks, and indeed the concept has been explored in various media such as Girls Und Panzer or Heavy Object. [Answer] This can never be viable. For the simple reason that armor does not work like most people imagine, not in any universe based on our own physics. Please see this battleship armor: [](https://i.stack.imgur.com/SunxU.jpg) It can be made thicker still of course, but there's no depth of armor that will protect against such. Sure, we can posit a few ideas that overcome the *other* hurdles... a nuclear reactor as a powerplant so it's not guzzling 500 gallons of diesel per minute, specialized ships to be able to sail one (or maybe two) across an ocean. But, at the end of the day, armor is to protect the occupants of the tank from *small arms fire*. You've just watched too many Ironman movies where Tony Stark takes a 50mm shell to the chest and bounces back. Even today, with specialized man-portable weapons designed to pierce tank armor, they don't matter as much as they used to. IEDs, rocket propelled grenade, anti-tank rockets. What happens when they start using those tactics to scram your nuclear reactor with 150 crew inside? When they do that to the behemoth that was projected to cost \$25 billion per unit, but ended up costing more like \$42 billion per unit due to cost overruns? How many of those can you lose before you've lost the war? You don't even get the element of surprise here, let me remind you. You can hide your latest fighter-bomber in some skunkworks lab and fly it out of Nevada late at night for testing. But your destroyer-sized land vehicle won't be kept a secret from the only guys you hope to use it against (tell me you're not thinking this will be used in minor skirmishes and conflicts). Just to train up the crew, they're going to need to be on patrol most of the time. As much as I might relish the idea of it just rampaging through rural Alabama on its maiden voyage so that the crew's not completely green, there are senators whose constituency might balk at the idea. And, if somehow you can handwave all that away, you've *still* painted a big red bullseye on it with the label "send all tactical nuclear weapons here, c/o our debt-riddled defense budget". The fate of all such vehicles thus matches their spiritual predecessor, Futurama's Land Titanic: [](https://i.stack.imgur.com/iF91q.png) [Answer] # Electronics became increasingly important in warfare but were never miniaturised Modern electronics provided so many new capabilities - fire control, meteorology, radar, thermal imaging, encrypted communication, navigation, and the computerisation of logistics, asset tracking and military strategy. Unfortunately, the integrated circuit was never developed and numerous other components were never miniaturised. Ultimately, it became necessary to bring a computer into the theatre of war. Your tank carries an electronic computer with hundreds of thousands of thermionic valves, ten of megabytes of core memory, hard disks and a team of computer technicians all in a climate controlled environment. It scans the battlefield with radar and cryogenically cooled thermal imaging sensors. It can automatically analyse the readings it takes, and track friendly and unknown units. It carries an atomic clock which, in conjunction with other giant tanks, set up a kind of land-based GPS for friendly units. It can accurately locate enemy guns just by the noise they make, and bring in accurate artillery fire in a moment. With readings from its environmental sensors it can run weather prediction algorithms. It can intercept enemy transmissions and potentially break enemy ciphers. The tremendously accurate real time picture it has of the battlefield around it can be encrypted and automatically transmitted over radio, and at network of these tanks create a real time coherent picture of the battlefield that make allied units far more effective. [Answer] ### Enemies that can only be defeated by naval cannons. If you want an excuse for the use of giant land tanks armed with naval cannons, then the obvious solution is to throw them up against foes that can only be meaningfully harmed with naval cannons, and which are positioned in places where the traditional vehicles for mounting such weapons (naval vessels and trains) can't access. Smaller tanks or artillery are insufficient because their shells just bounce off of the naval battleship-grade armor of their enemies. For instance, perhaps the enemy has a massive network of super-hardened bunkers with multiple feet of armor plating protecting them and bristling with anti-tank and anti-aircraft weapons, or there are nuclear rocket-powered space battleships that are capable of atmospheric maneuvers. [Answer] A war against hyper genetically engineered animals. With claws sharp enough to get through light armour (Up to IFVs) & able to take small arms fire. If these bugs get large enough they could get through regular tank armour. As to rule out regular super heavies in the 80-200 ton range they could get up the the size of a Dreadnoughtus: [](https://i.stack.imgur.com/z1XGE.jpg?s=512) The largest known land animal know to have lived at 59 tons. This would leave tanks of the ultra heavy size useful. As they would be the only things able to have enough armour to resist the bugs of this size. While very big guns would not be needed. An array of smaller weapons like HMGs, AGLs & autocannons would be ideal. Alongside mortars, thermobaric rocket launchers like the TOS-1 & a few smaller (75-100mm) tank guns for the larger creatures. At this size they could also be able to carry weeks to months worth of supplies without having to leave the tank. To not put people at risk by having to leave the tank to get supplies on a regular basis. Living quarters. Even small laboratory facilities if the vehicles is big enough. Maybe even mining truck sized vehicles with big cranes could be used to make it so that you wouldn't ever have to leave one of the big vehicles inside an infested area. [Answer] # Bedrock highway One could imagine a very particular type of terrain which would defeat conventional tanks - marshy, boggy, muddy, swampy - but which still had bedrock relatively close to the surface. A sufficiently large tank could squish the soft terrain out of its way in the same way that a conventional tank squishes small puddles out of the way. Let’s say there is a field of battle consisting of 3 metres of mud underlaid by solid rock. A normal-sized tank would sink into it, so build your tank to be 30 metres tall and 100 metres long, or whatever proportions allow you to treat the underlying bedrock as the actual road, with the mud pushed aside as a slight inconvenience. Megatank too big a target? Give your army prodigious manufacturing capacity so they can build hundreds of them. Megatank needs lots of fuel? Give it lots of fuel and make the military objective worth it. Megatank is a sitting duck for aerial bombardment? Give it active defences and put a runway on top, so it can create its own air supremacy like an aircraft carrier. Megatank would be useless in other types of terrain? That’s OK, megatank is a highly specialized weapon. Megatank would sink into really deep mud? You need Gigatank. [Answer] > > What kind of war would lead to Ultra-Heavy tanks being useful? > > > The kind fought on your home turf. Imagine the opponent with enough gall to attack a nation with enough disposable income for a super tank. If this is what they're showing, then what are they not showing us?!?! From my [other answer](https://worldbuilding.stackexchange.com/a/140683/17025) about the practicality of dragon blood quenched swords; it's just for show. [Answer] Ultra tanks cannot exist, because modern human technology is very good at destroying tanks and ease of destroying a tank is proportional to it's size. And bigger tank means bigger economic damage when one is destroyed. My solution? Make your tank fight against something that's not human. Zombies, alien monsters, anything that doesn't know how to use a rocket launcher or set up a mine field, but is still an existential threat to unprotected population. Such tank would function as a mobile fortress, with many smaller guns for protection, but it's main function would be to get the hell out, when wave of the enemies gets overwhelming. It would be powered by nuclear reactor and house entire towns inside it with all the ususal facilities. I would imagine humanity moved to living in the oceans because huge ships make more sense than huge tanks, however some of those tanks have been created to traverse the land when it is for some reason required - for example trying to reach remaining survivors on land and bring them to safety on the ship. Because of the infrastructure collapse, oil industry completely shut down and uranium became the only reliable, long lasting fuel source, which pushed humanity to construction of huge vehicles with huge capacity. If combustion engine was still a thing, conventional convoys would probably be a better options for such missions. Or maybe the monsters came from the ocean and humanity can only survive on land? If this is for a story, it's good to show how regular fortresses fell by being overwhelmed and escape became the only option for humanity to survive. [Answer] Any and all futuristic setting using humans already makes the leap that we somehow haven't utilized our advancing technologies. In fact as our computers become smaller it becomes easier to build smart artillery shells to destroy targets, meaning that the days of the tank are already numbered. Worse still is that most sci-fi is more of a WWII style combat despite its technology, with armored vehicles often fighting mere meters away from each other. So with that leap of logic already in, why not justify your tanks with similarly barely explained "its just the way it is" arguments and let suspension of disbelief take over? That said some extra justification is never a bad thing: It is not just a tank, but a mobile base to protect the inhabitants from the world outside. As an example the Arctic cruiser, although this concept failed: <https://en.m.wikipedia.org/wiki/Antarctic_Snow_Cruiser> The tank houses things like water recycling, air filtration and living quarters for the crew, as well as spare parts and maintenance equipment along with protective suits they can wear to maintain the tank's exterior. The tank has weapon systems to deal with the threats outside, and some barely explained phenomena protects against high-accurate artillery and aircraft bombardment. Maybe some kind of point-defense is available capable of defeating such weapons but failing at doing the same with more direct attacks. Maybe a shield generator can only be aligned perpendicular to the direction of gravity. It doesn't matter what you choose, so long as it gives a logical solution and you are consistent. Dune for example explains that shields protect against high-speed projectiles, but not how they work. That is fine, as long as you remain consistent. Sound in space is common too, as is a WWII combat style for spacefaring craft. Those dont even require explanation for the reader to understand, so long as you remain consistent in its execution. [Answer] The atmosphere of the whole planet is hostile to life. You can't set foot outside without dissolving/freezing/burning/getting irradiated and so on. Frequent nuclear conflicts have made the concept of a city unviable. The only way to survive is to keep moving and to be well protected against the environment. There are mega-tanks on the planet and pretty much nothing else. Each is its own city, powered by a plutonium generator. They keep on moving to avoid being targeted by nuclear strikes. Alternatively, you could have mega-tanks on a planet with one giant very flat landmass and no water. The tanks would essentially act as a land replacement for aircraft carriers, deploying effective short range air units that can quickly resupply on the mega-tank. Finally, if you're ready to give the tank a large number of very strong legs instead of treads, you can make it capable of handling a far larger variety of terrains, at the cost of potential stability issues (especially in combat). [Answer] Ablative armor and plasma shields provide a huge defensive advantage, but only at the cost of requiring super heavy tanks. Generations of warfare have resulted in more-or-less static kill zones between the few remaining nation states. Anti-air systems are so efficient, that almost nothing flies anymore. Cheap and effective rail guns have destroyed all orbital platforms. Even weather satellites were destroyed long ago. One of the nations, hatches a plan to change the nature of warfare. The goal is to push into territories where they can extract more minerals. It's a gamble, that they will deny each of their enemies of critical resources fast enough that they can gain sufficient advantage to finally create a tipping point. But they have to begin mining operations within what will be an extended kill zone, in order to reap the benefits of those resources and continue the push. Their engineers have designed massive, automated, mobile mineral processing machines, but how to defend them? The answer is to make them even more massive, and turn them into walking offensive and defensive gun platforms, with sufficient armor and power to survive in the kill zone for several months. They manage to keep this hyper-heavy project a secret by constructing them underground, just a few kilometer behind the front lines, where they will be used. But that's obviously not enough for success. They also scale back their production of super-heavies, in favor of cheaper, lighter/faster units that they can build by the millions. These will be used to race across the kill zones in areas far away from the hyper-heavies. A combination of super-heavies and ultra-lights will push towards several enemy cities. To achieve their goals, they have to weaken their lines in some places, to redistribute their forces, and they make it obvious to their enemies. The timing of each phase of the operation is critical. First, disinformation is "leaked" to known spies, that there are military production issues reducing production rates when in fact the opposite is true. They hope at least one, if not both of their enemies will take the bait and attempt to gain more or less useless territories for their own propaganda purposes. The fast faints towards enemy cities comes next. Starting with heavy bombardments from the static guns and super-heavies, then a slow push forward, followed a week later by the ultra-lights. The later, just race right on through the enemy lines, killing only lightly armored forces when they are in the way, rapidly routing around everything else. The goal here is to draw enemy forces away from the quieter areas on the line, to defend against what is perceived to be an obvious (counter) push for territory. Then the hyper-heavies, flanked by a concentration of super-heavies, push towards the needed resources. Several streams of them roll out, one behind the other. They must create and defend a bulge several hundred kilometers deep and wide. Each individual hyper-heavy is capable of hitting targets up to a thousand kilometers away, making it costly for their enemies to get close enough with enough concentrated fire power, to degrade the hyper-heavies. If they succeed, their enemies will never be able to match their new production levels. If they fail, there will be two waring nations left on the planet. It's a huge risk scaling up attacks against both enemies, but they can't take the chance that they will contribute to weakening one of them, while the other also takes advantage and has enough time to adapt to the new strategy. [Answer] Hmm, I think you might only have to take one thing off the table to make this within a suspension of disbelief. (Mega tanks still probably not the best solution by a long shot but being remotely feasible) Kill manueverable airpower. Let's say higher wavelength light sensors like infrared and visible spectrum coupled with higher computing power have made radar-defeating stealth obsolete, and the same setup has made laser point defenses and anti-air effectively impenetrable by craft and rocket propulsion. Nothing that needs guidance can reliably deliver a payload. Now to reach a distant enemy you need weapons with enough mass and momentum to minimize air interference with accuracy, and to make interception less relevant as the payload is still arriving with huge force whether in one piece or in several. So you turn to magnetic acceleration: railguns. We haven't developed anything like miniaturized fusion yet, so the power supply needs to be enormous and probably a small fission reactor. And we don't have mass production of diamond hard materials, so the rails need to be very long to accelerate the ordnance at Gforces it can withstand. You can't just keep this gun in one spot, and you don't wanna keep it on a known railway, or the enemy won't need guided weapons to counterfire. So you make an enormous platform to move it around between volleys. It has enough range that you're not worried about hazardous terrain unless the enemy wants to abandon hundreds of miles to your lighter mobile units, just go around. But you don't want it to be forced to stay ONLY on major highways, it should be able to deal with dry mild offroad terrain, so you scale up the volume and surface area touching the ground to allow the monster not to sink into EVERY offroad condition. This makes it really, really slow. But that's fine. Tactically it only needs to move outside the impact range of accurate counter battery fire. It never approaches the front lines or gets within the horizon of the enemy. It also doesn't really care about armor beyond shrapnel or small arms fire. No weight of armor will save it against a bullseye slug traveling at several km/s, in fact over penetration would be the best slim hope. Which means more mass allotment for power supply and delivery systems. It doesn't sound much like a tank, but it's kinda like comparing an age of sail ship to a ww1 Dreadnaught which though it DID have heavy armor, had very little at the water line because primary concerns of sailing ships at 500 yards became irrelevant for angles at 12 miles. And just like that comparison, I'm sure something like the torpedo would come along to sink this magtank within a decade or so of its deployment. [Answer] A conflict in hostile environment(s) where units have to be deployed for prolonged periods, constantly mobile, with 24/7 readiness. I'm assuming the Tank is nuclear powered in this case, and is essentially a bit like a land going Nuclear Submarine. The extra size is partly a result of needing room for the things a Tank doesn't normally have - kitchen/eating/sleeping/sanitary facilities. Just barley enough room to move about and keep apart that the crew doesn't go insane on a deployment lasting weeks. The crew would be larger too to allow for three watches. With a nuclear reactor providing power, in a near future setting weaponry could be quite different to that we are used to. Laser point defence and railguns. The thing could have its own air wing and infantry with a number of missile armed drones and gun armed mini tanks (or walkers of whatever design you like, robotics technology permitting). [Answer] Very large vehicle can be useful in warfare. The U.S. military does build and operate a small number of very large vehicles. These are aircraft carriers, destroyers, battle ships etc. **Instead of thinking of the super heavy tank as just a larger version of a regular tank, think of it more like a navy ship.** Its a big platform where you can combine lots of really powerful but large and expensive technologies. **BETTER DEFENSE:** Small battle tanks might have something like an Active Protection System. But the super heavy tank can have something like the Phalanx close-in weapons system. This system automatically tracks and shoots down any incoming threats. Forget energy shields you just have a wall of lead. <https://en.wikipedia.org/wiki/Phalanx_CIWS> You can combine that with missile systems like Iron Dome and David's Arrow to create a complete missile defense system around your super heavy. This protects not only the super heavy but all of your smaller vehicles within the protection radius. **BETTER OFFENSE:** A regular tank might shoot 160mm shells with ranges of a mile or two. But the super heavy tank can have a railgun. Railguns typically require large capacitor banks and some sort of large generator to charge them. But the super heavy has room for that. Railguns have insane range (like 200 miles). If you park the super heavy in a wide open space no one will be able to get close enough to you to even get a chance to fire at you. **NEW TYPES OF WEAPONS:** You can't put a battery of cruise missiles on an ordinary tank, but they fit nicely on the super heavy. **USE IT TO CARRY SMALLER FIGHTING VEHICLES:** The super heavy is large enough that it can carry a crew of hundreds, and launch swarms of drones or even other tanks. Its like a land based aircraft carrier or a mobile base. **BETTER DRIVING RANGE:** Regular vehicles use gasoline. Like a navy ship, the super heavy is large enough to fit a nuclear reactor. Now you only need to fuel up every 10 years. **BETTER COMMUNICATIONS:** Communications wins battles. Smaller tanks are always starved for power and space. Their radios have limited range and bandwidth. Long range communications is either very limited or relies on satellites. The super heavy has room for large communications antennas and radio equipment. Its extra height gives it a very far line of sight. Its much harder to jam communications because your radio is now larger than the jamming equipment our enemy is using. [Answer] ## Post-Apocalypse / Hostile Planet The scenario is either post-apocalypse or takes place on a world with a naturally inhospitable environment (like Venus, for example). The surface of the planet is so hostile to life that people can only survive there if protected with thick armor plates. Humans live in large underground shelters or heavily fortified surface bunkers all around the world. Those shelters require resources which are found on the surface, and there is not enough for everyone. So those colonies wage war against each other wrangling for control of these resources. That means that they are going to need some field operating bases. But those are difficult to build if you need really thick walls to protect yourself from the environment. So ultra-heavy tanks could serve as mobile bases. Their spacious interiors would serve as command posts, medical facilities, logistic centers and/or repair facilities for smaller battle-tanks. Those tanks would usually be vulnerable to aerial attacks or cruise missiles, but the hostile atmosphere might also offer an explanation for why those are infeasible. [Answer] The biggest land based vehicles are bucket wheel excavators. They are used to dig out vast quantities of dirt. If you look up a bucket wheel excavator (e.g. bagger 293), they kind of already look like gigantic tanks. There are a few reasons that you might want to have an ultra heavy tank which is similar to a bucket wheel excavator. **Excavation.** For some reason, your military goal involves digging up a lot of dirt. This might be because you need to dig a dirt highway for logistics reasons, you need to create dirt airfields a lot, or you simply want the dirt - wars are fought over minerals and natural resources often. If you're trying to extract resources from a technologically inferior enemy nation, one way to do it is to build a titanic mining machine, cover it in armour so they can't effectively harm it with small arms fire and weapons so they can't get close enough to board it, roll up, take their ore deposits, and leave. **Moving really heavy things.** Suppose you have a supergun. It can sink battleships from hundreds of miles away. It's a tactically valuable tool, but you only have one (or a few) of them. You want to be able to relocate your supergun for strategic purposes, and the normal way to do that would be to disassemble it, throw it on a fleet of trucks, and ship it. Problem is, disassembling something as big as a supergun takes a day at least, so does reassembling it, and transporting isn't speedy either. If you take your supergun offline for days and the enemy finds out, you're doomed! So instead, you make it mobile. Build a bucket wheel excavator looking thing, replace the mining machinery with your supergun, and now it can move a few miles a day (faster if that's a design priority) and still be 10 minutes away from firing at all times. If you can keep your supergun moving at 10 miles a day, and if everything in a 100 mile radius of your supergun is captured territory, you can leave from Warsaw and capture Moscow in 2 months. [Answer] They called it the Second Noah Flood. Sudden changes in climate led to worldwide rains like nothing ever seen. For endless months, it rained without cease. Earth turned to mud. Metal rusted. Concrete spalled, fractured, and collapsed. Hills and mountains eroded away in tidal waves of mud. Homes, towns, sometimes entire cities simply washed away and scattered across the landscape. The earth of today is not as it once was. Forests, plains, pastures, hills - all has turned to swamp and mud. With the destruction of farmland came widespread starvation. Billions perished. Those that remain are mired in the final conflict - the war for food. There are no roads now, and no automobile can traverse the endless muck. Only the ultra-tanks - lumbering multistory behemoths constructed in secret facilities that remained safe in the bowels of the earth - can move across the quagmire. Carrying the last remains of humanity, they seek food. Food at any cost. ]

[Question] [ An adventurer has come into possession of an invisible sword. How advantageous in a duel or skirmish would this be? Good for a one-time trick, a significant advantage throughout a fight, or even a disadvantage? Some background detail: **Setting**: Low-magic, late-medieval setting. Other strange artifacts like this might exist, but no spells or healing potions, etc. **Adventurer**: Experienced adventurer and duelist, but average strength and size, and no sword-master. Personality is more suited to tricks, gimmicks, using wit etc. **Fights**: Duels and skirmishes. No large-scale battles but conflict more on the line of a duel for honor, a bandit raid on a small party, etc. **Options**: If there are any specific things that would make it more useful, such as type of sword, having the handle visible, any extra equipment, feel free to mention. [Answer] **Very Advantageous**. But with careful use. Obvious use is assassinations, since it can let your guy appear to be unarmed. He can even do it in public, and frame a nearby armed person. For a duel, he will need a visible weapon to maintain pretenses. Then he can sneakily stab the opponent who is focused on parrying the visible weapon. For extra equipment, can try attaching a visible dagger to it, to explain away the swinging and stabbing motions that the wielder is doing. **Disadvantages** * It cannot be used to threaten somebody, or deter them from attacking. * The wielder himself cannot see it, which can get dangerous, especially if he is trying to parry with it. * He might get accused of using magic, which will have consequences. * If the sword gets bloody, will blood be visible? If so, he can only use it once per fight. [Answer] The primary advantage would be surprise. I'm trained in eastern martial arts including swordfighting. I was trained to **not** look at the weapon, but at the body of the opponent. The weapon moves too fast and will confuse your focus, but upper body and arm movements telegraph the sword strike a long time before it actually happens. A well-trained opponent may not even notice that your sword is invisible since he isn't even looking at it.(\*) But at the beginning of the battle, the opponent would not realize that you are holding a weapon at all. You might want to wrap something like a paper scroll or something around the handle to mask your unnatural hand grip, but especially if you gesticulate a lot while speaking (for safety reasons, primarily with your other hand), you could well land a nice swing before your enemy even understands that you are holding a weapon at all. In a prolonged fight or battle, there would be a small advantage, but the ideas outlined in other answers to hold a smaller weapon in addition so that enemies use a false distance assumption is probably the best use. --- (\*) anyone who answered that it would make parrying difficult if you can't see the blade doesn't have swordfighting training. I don't need to see your blade to parry it, I only need to know the direction of the swing. I would not try to parry a thrust, ever, I would sidestep it. Again I don't need to see the blade, the arm tells me enough about where the thrust goes. This might be different in western-style swordfighting, but I can't imagine the difference is huge. [Answer] [Bald Bear](https://worldbuilding.stackexchange.com/a/129092) basically nailed everything I was going to answer except for one particular other use I saw once in an anime called Get Backers. In the episode I watched, a bad guy got into a swordfight with one of the main characters. The hero kept being hurt by the sword even though he as pretty confident in his skill to dodge the blows. Still, he kept being hit time after time. The explanation for that is that the attacker's sword was actually a few inches longer than it appeared. The additional inches were invisible, which gave him an incredible advantage early on - if one of these attacks got, say, his throat, that would have been the end of the fight. [Answer] A very good fighter is able to gauge their opponent's range and uses that to both predict/defend against attacks as well as strategizing their own attacks. An invisible sword would be much harder to gauge and thus create a significant advantage for the wielder. This was used in the anime series "Fate/stay Night" where one of Saber's special power was being able to shield the length of her sword. The primary advantage would be in 1 on 1 duel type settings. This would have little advantage in a large group skirmish as one rarely has time to stop and closely evaluate range in that kind of setting. Additionally, it would actually be a determent in an intimidation type scenario. With intimidation, size matters. Since you can't show just how impressive your weapon is, you can't use it to intimidate. [Answer] Naively thinking, it would be the ultimate super weapon since you can hardly defend against a weapon that you can't see, but realistically it's far from that. It may be great for murdering someone and for carrying it to places where weapons are banned. But in a fight, it would not be much of an advantage. Many medieval sword techniques were surprisingly sophisticated and do not actually require that you see the opponent's sword (much like e.g. you do not need to see the opponent's hands in some martial arts, which once upon a time I thought was something very special and awesome, but it's actually no big deal!). An experienced fighter (you could kill an unexperienced one with a visible sword anyway!) will know what move to make based on your stance and arm movements, and it will work as good as if he could see the blade. You don't swing and bang blades together repeatedly like in the movies. You make a move which guarantees contact, and after that everything is about *feeling* and steering, while keeping contact. No sight necessary. On the other hand, if the blade is invisible, you cannot see it either, which isn't necessarily an advantage. Try and sheath it without cutting off a finger. Plus, blood (or dirt) that may stick to the blade will be visible, even if the blade itself is not, so the trick's efficiency is limited. [Answer] To add onto the other answers, if its a one handed sword you could easily fake out your next attacks in duels by grabbing the sword with both hands and then pretending to hold it in both , this would make it incredibly difficult for an opponent to block or parry attacks. For example you could raise one hand and pretend to do a slashing strike with your empty hand causing your opponent to try and block it, and then use the actual sword hand to for the real attack. [Answer] The late medieval period was characterized by the movement away from full plate armour and combat swinging slashing/chopping swords and crushing/penetrating maces and hammers, toward unarmoured combat, armed with thrusting swords such as rapiers and foils, and light cut/thrust weapons such as sabres. As Tom has pointed out, when using a slashing sword, whether it is a broadsword or a katana, a long stroke is required to cut through armour, and even if the opponent is 'unarmoured', unless the blade is razor sharp, even ordinary clothing - especially if made from silk, as would be the case for samurai - could prevent serious injury. In such a case, as Tom has pointed out, even to an indifferently trained swordsman, even if an opponent's blade was invisible, that opponent's movements would be declaring their intentions quite well enough to defend against them to a reasonable degree. However...! The European movement toward unarmoured combat - that came to pass due to the rise of firearms in battle that made all but the heaviest, most expensive armour effectively useless - led to the invention of thrusting swords. These weapons were designed for sheer speed - life or death was measured in fractions of a second, inches of movement and surprisingly little force. Three inches of extension and 100g of pressure from the point of a thrusting sword against an unarmoured opponent was the difference between life and death, when delivered to a vital area. When fencing with western thrusting swords, the difference between a successful parry and an unsuccessful one could be a matter of a few inches of movement of the tip of the sword, probably no more than 4", possibly less. As someone with training in modern fencing, I can say that being able to see the position of the tip of the opponent's sword is of *vital* importance - my instructors made that quite clear. Since the sword's tip need only move 3 or 4 inches in order to avoid an opponent's parry, and the sword may be a metre long, very little movement of the hand or arm is needed in order to achieve that movement. Since one need only apply around 100g of pressure in order to penetrate clothing and flesh with a needle-sharp blade, and need only penetrate the opponent's body to a depth of 3-4" in order to cause a potentially fatal injury, the only obvious part of an attack is the thrust itself, since there is no magnification of movement caused by angles over distance. Since a fencing blade need only be held very lightly, a moderately skilled fencer can conceal the slight movement of his arm and hand with even slighter movement of the fingers. This is what *makes* being able to see the position of the tip of the opponent's sword so vital. An invisible sword would be of no use in a formal duel. No honorable second would allow the use of such a weapon (as they take charge of the weapons until it is time for the duellers to take them up), and somehow managing to use it would instantly brand the wielder as a person completely without honor, and likely lead to their being quietly stabbed in the back in some secluded location at a later date. However, in an undisciplined street brawl or upon a battlefield, while an invisible sabre or katana would be merely somewhat disconcerting to the opponents unless they were untrained, an invisible rapier would be utterly terrifying even to the most highly trained opponents. The wielder would, with only a little practice, be easily able to handle the sword's invisible nature and parry an attack, but the opponents would be guessing blindly, quite literally, when it came their turn to parry, and with only a little skill, a simple disengage against a lucky parry could reverse the situation. Even master fencers could fall quickly to an indifferently trained opponent wielding such a weapon. An invisible rapier might allow an indifferent fencer to prevail against odds of 2:1 in all but the most unfavorable situations, and in favorable circumstances, they might stack up the corpses of their opponents in piles too great for their comrades to climb across. Were that to happen, no doubt archers, arbalestiers, musketeers or even slingers would be called so tha the swordsman with the invisible blade could be shot down from a safe distance - if any were available - or an armoured swordsman could be called, against whom an invisible blade would be at even more of a disadvantage since the wielder of the invisible blade would not be able to aim for weak points in their opponent's armour as well as if their blade was visible. Otherwise, one man with an invisible blade and a narrow passage to defend could cause an entire army to retreat, as long as their endurance held out. Fencing is surprisingly exhausting. The constant movement is a good cardio workout, so as long as opponents were willing to keep coming, even after the comrades who preceded them had all fallen, sooner or later, the defender will become exhausted and will be unable to continue defending. If they have any sense, they'll retreat before that point, and if defence of their position is a matter of life and death, having 2 to 5 comrades, all of whom have practised with the invisible blade, could allow the defenders to hold off an army of unarmoured swordsmen indefinitely. They just need to hope that their assailants don't think of throwing rocks... [Answer] One other advantage of this sword is that your opponent doesn't see your grip on the sword, meaning that with **unconventional grips**, your opponent may not be able to tell where the blade is coming at him. Even better, you can use feints that wouldn't otherwise be possible, because your opponent has to attempt to block every stroke you use, even when the blade may be nowhere near him, causig him to expect a block, then **be put off balance when he meets no resistance.** Also, your opponent will never know if you've been disarmed or not unless you fake a block instead of a dodge. If you really have been disarmed, you can continue to attack and pretend you have the sword while you find a way to flee or recover the sword. *Of course, if you are disarmed, recovering it may prove impossible, as you can't see it*. That's about the main disadvantage I can think of. Your opponent also will not know which hand your sword is in, so if you make sure he sees you put both hands on the grip, then hold it in one hand, they won't know which hand it is in. *Suddenly, when attacking you have two swords the opponent must contend with!* The effect is easier to pull off when the trick is done behind the back, so the hands can't give away the movement of the sword. When practicing, it may help to put something on the sword that allows you to see it, creating a greater awareness of the sword and its range and position. *It would be to your great advantage to attack aggressively with the sword rather than defend*, as when your opponent attacks, he doesn't really care where the sword is. Either it's in the spot that will block his attack, in which case he knows exactly where it is, or else you didn't block it and you're dead anyway. When attacking, your opponent needs to know where the sword is in order to block it. *Pretending to throw the sword would be extremely effective.* As the defender must attempt to block every time for fear that you really did throw it, you effectively have an unlimited supply of projectiles your opponent must defend against. And if he doesn't block, really do throw it to win the fight. [Answer] You ask for situations of a duel or a skirmish. **Useful additions-** A sword with a notch which can be used as a 'sword-breaker' could be useful to quickly disarm the opponent in a swordfight, especially if the adventurer is careful to keep the presence of the notch secret until his chance comes. SO he basically will have a one edged sword, but he only has to turn it around and the opponent's sword will get caught in a notch. TBH I do not know how exactly sword breakers work, but I think most opponents will not consider the possibility that their sword will get stuck in another sword, even if they consider the same about the protective gear. Note that sword breakers are usually shorter and thicker than other swords, but an invisible notch would definitely be a surprise. ! [sword breaker] (<https://www.medievalcollectibles.com/images/Product/medium/ED2206.png>) ! [ **Additional Benefit** One aspect that other answers do not cover is- An invisible sword can be brought into places where swords are not allowed or where people are frisked before entering. **NOTE**: My answer assumes the adventurer can either see or sense the sword when it is away from them upto some range. When in hand, the adventurer can be used to the sword length by practicing. Possible solution- Using the magic you mentioned, there can be a bond between the adventurer and the sword. This will also prevent losing the sword. **NOTE**: The adventurer may actually be better fitted with a visible sword and an invisible weapon. This concept is mentioned in a previous answer, but my suggestion is the invisible weapon be a dagger as wielding 2 swords may not be much easy in practice or may be easily noticed, a dagger being used is not easy to notice(most assassins I have seen or read used daggers instead of swords). [Answer] **You can throw it.** If it is a sword, rather than a dagger, then you can reforge it into a dagger. He can practice throwing by simply covering the dagger with mud. Once he can hit targets, he can kill anybody from middle range because the enemy won't try to dodge the dagger since he can't see it. Additionally, you can split the sword into thin pieces instead of a single dagger to throw during bandit raids. [Answer] The invisible sword has a major disadvantage: No competent friend would dare help its owner in a melee. This means that its owner is more likely to be outnumbered, and will never be able to outnumber an opponent in close-in fighting. [Answer] As a good swordsmen, the user should not have to see the blade to know where it is in relation to the opponent, however, its usually nice to validate where the tip is to gauge its position relative to the opponent. Parrying could be difficult. The user would have to have ultimate trust that the sword edge, point and length are exactly as the user thinks they are. (a swordsmen periodically validates their form and position by using peripheral vision during combat.) One advantage in a stand off. The opponent may inadvertently walk into the point as they position for a good striking position. I can see the user being just as stunned as the opponent. [Answer] It would give you a huge advantage, the element of surprise. For one on one combat, you can seriously injure your opponent before he realizes you have an invisiable weapon. -You could just sneak attack him before the battle begins (not very honorable) -You could hold a dagger AND the invisible in the same hand. This will seriously confuse your opponent -You could hold a real sword in one hand and the invisible one in another hand allowing you to back stab him However in one against many, this wouldn't be very useful. The biggest problem I see is that eventually, rumors will spread about your invisible sword and soon enough, the king's personal elite guard will be after you to confiscate your magical sword. ]

[Question] [ The year is 1,000 BC The Rock Tribe, apart from liking very loud music, makes war by throwing rocks. In close combat they can use rocks as primitive (non-handled) clubs. The Scissors Tribe naturally use [scissors](https://en.wikipedia.org/wiki/Scissors) of varying sizes. Scissors can be thrown or used for hand-to-hand combat. These scissors are primitive, made of bronze and have a maximum length of about 1ft (30cm). The Paper Tribe. Uh ... They make paper. At one time or another any two of these tribes will be in dispute with one another. This causes them to go to war. How can I save the Paper Tribe from getting massacred? --- Ancient scissors: [](https://i.stack.imgur.com/crsdt.png) [Answer] # Paper Armor [](https://i.stack.imgur.com/cOEO1l.jpg) Believe it or not, this was an actual thing; the Chinese used it for nearly a millennium as one of their main types of infantry armor. In addition to the obvious decreased cost factor, it also is *much* easier to repair (you just sew on replacement wads), and is much lighter than metal armor. **Here's how it relates to your problem:** **While it's extremely effective against being beaten over the head with a rock, it isn't as effective against stabbing weapons.** As a result, while it is a superb defense against the Rock Tribe, the Scissors Tribe will have a much easier time murdering the Paper Tribe. This keeps the traditional balance of power in Rock-Paper-Scissors intact. [Answer] ### You have a few options [**The Millwall Brick**](https://en.wikipedia.org/wiki/Millwall_brick) [](https://i.stack.imgur.com/ZLVDg.png) A type of brass knuckles made with folded and rolled newspaper. Often used to beat up your opponent's fans at a soccer game. **Paper Mache Cross Bow** [](https://i.stack.imgur.com/ziLW1.jpg) As tested by Mythbusters. Paper and things availing in maximum security lockup only. **Paper Mache Shank** [](https://i.stack.imgur.com/aWRst.png) As made by a prison inmate. This is solid toilet paper dried into a solid shaft. This looks pretty solid and beefy. **Paper mache club** [](https://i.stack.imgur.com/nlPlg.png) **Minor technical note** The paper tribe won't exist for another [1025 years](https://en.wikipedia.org/wiki/History_of_paper) after your setting. Paper was first known to be made in about 25 AD. [Answer] # Cunning The paper tribe has developed written language, which they have used to record their history and collective knowledge in books or scrolls. What the paper tribe lacks in materials, it makes up for with brains, experience and cunning. Some general ideas: 1. Perhaps they have mastered the use of fire in warfare, paper does burn very quickly. 2. Paper is light, and they too might be a very mobile tribe. It is hard for an enemy to attack you if they don't know where you are. 3. The production of paper is dependent on various crops and plants. Which means agriculture, which can give them a huge numbers advantage, as they can support a much larger population. Even if they don't have weapons, it's hard to overcome a 10:1 numbers advantage. (this is on theme for them being able to "Cover" rock.) [Answer] Ash mentions at the end of that answer: > > The paper tribe won’t exist for another 1025 years after your setting. Paper was first known to be made in about 25AD. > > > To make it era-appropriate, consider making the "paper" tribe a "[Papyrus](https://en.wikipedia.org/wiki/Papyrus)" tribe. It could used similarly to paper for making shields/armor — as mentioned in another answer — that renders the rocks ineffective, but, being a bit tougher than paper, it could also be weaponised e.g. fashioning some kind of spear/javelin from it... although still not nearly as effective as the (metal) scissors. Papyrus in its raw (plant) form has the fibres naturally aligned, so keeping them aligned would make construction of a weapon shaft easier than starting with something paper-like. [Answer] Paper covers rock...s expenses. They use paper money and contracts and treaties to blackmail powerful foreigners and hire mercenaries. They fight with their wallets and as such never enter battle directly. If the scissor tribe goes to war with the paper tribe, they find themselves fighting rock warriors and vice versa. It is in the interest of both the rock and scissor tribe that their valued trade partners in the paper tribe are not wiped out by their enemies. ]

[Question] [ Imagine that when Christopher Columbus sailed West in his [Carrack](https://en.wikipedia.org/wiki/Carrack) to travel around the world to reach India, he had never made it to land, because halfway across the Atlantic Ocean between Europe and America his ship was attacked. It was a creature that no one had ever seen before, and no one lived to tell the tale of its existence. So what kind of a creature could have done this? --- There isn't any restrictions to the design of this creature, as long as it can realistically live on this planet in the ocean. It can live in whatever population, social dynamic, or area required, and must be able to take down a boat similar to a 15th century merchant ship (of around 30-45 meters long). It can also be any type of animal (fish, mammal etc.), whatever is needed for the design. However, so as not to be too broad, I'll offer some reasonable assumptions that can be followed, although they are not required to be. --- It doesn't necessarily have to be a [huge creature](https://worldbuilding.stackexchange.com/questions/317/is-there-a-maximum-size-an-ocean-bound-creature-could-grow-to) to sink a ship, it could be a group of smaller creatures that worked together in order to take down the vessel. Whether it was a solitary monster or a pack of hunters, they likely only reside in the deep ocean far away from land. Now, obviously as this is the first boat to have ventured into their territory, in order to survive that long, they must have regular prey that they can eat to survive. So let's say they usually eat whales, and have mistaken this ship for a new breed of particularly large whale they have never seen before. To bring the ship down, they would be limited to doing it in the way that they are used to getting their prey. For example, if attacking a whale, the creature would likely need to tear chunks out of it until it dies of its wounds, or turning it upside down until it drowns. Either of these techniques could be used to sink a boat. It can also win by either ferocity and relentless attacks, or intelligence and teamwork, like [killer whales](https://i.stack.imgur.com/tY9mh.jpg) can do to knock seals into the water. [Answer] # Mega-AquaBoa-Constrictor The problem I have with animals biting the ship is that one bite would likely deter them. It seems like a lot of sea animals like sharks usually take one bite of something that they don't like and then move along. A hyper-evolved boa constrictor that has grown substantially large and evolved to adapt to deep sea water would be drifting around snagging wales by looping over them. Along comes Columbus and she soars up out of the water, lands over the deck, and constricts it, feeling the 'bones' begin to snap. But when she goes to eat it, she is disappointed. This can happen time and again, because the boats still look like the bellies of whales from below. Happy writing. [Answer] Give that Columbus' craft were built using Carvel construction (butt jointed wood caulked with tarred hemp that is hammered into the joints and then a coat of tar over everything beneath the waterline), and given that we have already found oil-eating microbes to exist.... imagine hitting a massive, dense plankton field saturated with hungry microbes in the middle of the ocean that just LOVE your flavour of tar? So, it wouldn't be a malicious attack, but once your craft lost its watertightness...it wouldn't matter much the intentions. And you could have fun with the crew desperately trying to disassemble the deck to hammer down over cracks, construct nails, and otherwise find ways to solve the issue of the myriad growing leaks as the ship takes on water, sinks lower, and exposes more weak seams to the sea. In this case it would be more the tension/survival story rather than a sea-battle epic, but could be fun to explore. To satisfy the "current diet" portion of the equation — the plankton field forms over a relatively shallow tar field that oozes enough oil to tar the plankton, resulting in a symbiotic relation between the microbes and the plankton. Your ship provides a moveable feast that the microbes jump on, multiplying exponentially with all that yummy food available! And maybe the critters are dormant under cold temperatures, so it's hitting the main tropical trade routes that is deadly. Or when a nice warm hurricane brings a plankton field north.... And, as a side, the Viking ships that previously sailed the north atlantic would have been just fine as they used lapstrake construction (overlapped boards held tight with rivets) that would not have been affected. [Answer] This is not as straight-forward as it sounds. Some problems as I see them: **1. Oceanic Exploration Not a New Thing** At the time that Columbus "discovered" the New World, the Vikings had already started and abandoned settlements in North America. Furthermore, many civilizations had already dabbled in oceanic exploration, notably *the Chinese*. There is also some evidence that Egyptian vessels may have reached South America, but I digress. What the point here is that human ships had been up and about the ocean for a while before Columbus came along. Since whales migrate, and this creature would probably follow its prey, what are the chances that no one else before Columbus would have encountered these creatures and not left some kind of record of it? Some survivor floating back to shore, or the horribly mangled corpse of a whale showing clear signs of having been ravaged by a predator. It would spark people's imaginations and stories would be told through the ages. Of course, you can justify this by having there exist *legends* of sea monsters, etc. **2. Eating Wood** A large squid, etc may very well attack a boat having mistaken it for a whale. The problem is that once it tries to take a chunk out of said boat it will soon find it rather more difficult than biting a whale. Furthermore, instead of being made of tasty flesh, this new prey is made of ... wood?! In order for this creature to persist in its attack, it would either have to: A) Be very, very clever and ***know*** that within the wooden hull are tasty humans that it can devour. Or B) Be incredibly territorial, and not tolerate any "newcomers" to the neighborhood. In other words it attacks the ship not because it is food, but simply because it's there. The problem with this scenario is that any creature which migrates (to follow its prey) doesn't have a set territory, and thus won't be territorial. **3. Conquistadors** There's not a lot of sea creatures which can take on a decent sized ship. Sure, a pod of whales working together can flip a boat, etc, but almost any creature that size does not have a vested interest in doing so - after all, human ships are not only difficult to deal with, they're also *quite heavily armed*. Remember that exploration and colonization went hand in hand with slavery and conquest, so these explorers were typically very well armed. In fact, those first explorers to reach the New World have been remembered not as peaceful discoverers, but as Conquistadors, who incidentally slaughtered the indigenous populations and toppled their civilizations. These guys could make short work of a squid or whale attacking the boat - especially since they usually traveled across the ocean in numbers, not in a single boat (not at the that point) **Now to answer your question:** What could take out a boat? As @bowlturner has pointed out, a sufficiently angry whale may do the trick. However, in my opinion, these things would soon find themselves extinct. Anything massive and vicious enough to take out a ship without survivors eventually either killing it with guns/cannons/harpoons, means that its attack must be both lightning fast, ***and*** devastatingly powerful. Especially if it must destroy small fleets of these exploratory vessels as they cross the ocean. So what would be needed? In my opinion, something from an age gone by. The Megalodon Shark comes to mind. Scientists disagree slightly as to how big this massive predator was, but most believe it was somewhere around 20 meters (that's over 60 feet) long. This bad boy had a jaw so big, and a bite so powerful that it could rip a smaller whale ***in half***. I quote from Wikipedia: > > Sharks often ***employ complex hunting strategies to engage large prey animals***. Some paleontologists suggest that great white shark hunting strategies may offer clues as to how C. Megalodon hunted its unusually large prey. However, fossil evidence suggests that C. megalodon employed even more effective hunting strategies against large prey than the great white shark ... Fossil remains of some small cetaceans (e.g. cetotheriids) suggest that they were ***rammed with great force from below*** before being killed and eaten. > > > In other words this massive predator would rush from the depths to strike its prey from below with devastating force. This thing would be clever enough to know that there's advantages to taking out a ship (*oh look, yummy treats are jumping in the water!*), as well as vicious and smart enough to take on a decent sized vessel in such a way that a harpoon, or gun would not help the crew in the least - it attacks from below, no one can see it coming. That's my 2 cents, at least. [Answer] The most realistic way—historically correct, even—seems to be a case of the overly hungry [naval shipworm](https://en.wikipedia.org/wiki/Teredo_navalis) (*Teredo navalis* var. esuriens). Columbus had a large problem with them, the knowledge about these critters got lost at his time and he wondered why his ships were literally falling apart under his feet[1](https://en.wikipedia.org/wiki/Teredo_navalis) (you don't see them, their entry holes are very small). But such an attack is more apt for the horror-genre, I presume, not so much for the *Real Action*™ section. [1](https://en.wikipedia.org/wiki/Teredo_navalis) Briggs, D.E.G. & Crowther, P.R. (eds): Palaeobiology II, Blackwell Science Ltd., pp.: 273-277; Oxford. [Answer] Why not go with the tried and true [Kraken](https://en.wikipedia.org/wiki/Kraken)? * It is large enough to take down a boat, and could easily live off of large aquatic life (whales, sharks) when boats are not around. * Give it the ability to digest wood, since most if not all ships of the era were constructed of wood. * Kraken are jerks, for lack of a better way to put it. They attack ships because they like wrecking stuff. * It is familiar to people already, being featured in popular culture depicting that era. * The creatures are *really* creepy and fill their victims with dread and hopelessness, which is really powerful when telling a story. There is nothing quite as meaningful in a story as surviving against insurmountable odds. While the Kraken is a legend, not real, we can infer several of properties that logically follow from other aquatic organisms: * Being a carnivore large enough to destroy a ship and eat humans, sharks, and whales whole, it is clearly a large apex predator. * Being a large apex predator, it would hang out a ways from shore similar to how whales rarely approach shore. It needs space which does not exist in shallow waters. This would insulate it from attacks from shore by cannon fire, certainly from guns, and any attempts to ambush it with a ship full of powder manned by a brave (or condemned) crew would be an exercise in futility. * We see in nature that [apex predators](https://en.wikipedia.org/wiki/Apex_predator) are relatively rare: it takes a lot of smaller creatures to form an equilibrium with a large, dominant predator. Too many apex predators, they eventually starve or kill each other: too few, and the population grows until it reaches that equilibrium For these reasons, I would expect such a creature to be relatively rare, and to be far from shore. Many ships could make it through shipping lanes untouched, but an occasional ship would simply vanish. Perhaps another ship would be close enough to see the attack or to rescue survivors handing on to flotsam, but this would be even more rare. Rare, but might still occur: and it would spawn stories and legends... of The Kraken. [Answer] My proposal is a bit different, in that it is not an outright attack: # Farting. A large whale is drifting a few meters below the surface, trying to clutch its stomach with its flippers and wishing it hadn't had the krill vindaloo and ten pints at the Rugby Club dinner last night. Suddenly an enormous blast of flatulence releases a huge cloud of methane bubbles into the water. The whale feels much better, but for Chris and his crew sailing above, as the water density plummets and their ship vanishes below the surface, their last smell is ... not pleasant. <https://www.newscientist.com/article/dn1350-bubbling-seas-can-sink-ships/> [Answer] An angry or protective Sperm Whale could [do the trick](https://en.wikipedia.org/wiki/Essex_(whaleship)). If it needs to be more exotic/unknown that hasn't had any contact with humans. why would it attack something so dissimilar from anything regularly visiting its habitat? I see three options: 1. Huge territorial creature (a new kind of whale, most likely). It will challenge and ram anything that it perceives as threatening its dominance. 2. A mass of something that breaks down wood. Something like Sargasso sea weeds, except that it has roots digging into the wood as if it were ocean floor. Ships would get stuck in it and while they could cuts the roots attached to the sides of the hull, they cannot reach under the ship to free the keel. After some weeks, the hull is Swiss cheese and the ship sinks. 3. Malicious intelligent creatures. These could be mermaids or anything really. They don't attack the ships for food, but because humans are enemies to them for some philosophical, religious or other reason. It's hard to give a specific design for these. [Answer] Large whales already exist and they have been known to smash whaling vessels. They usually attacked those ships as a form of defense but a 100+ft long whale could easily do enough damage to an old sailing ship that it would never make it home, or even sink outright. So We take one of the larger whale species, sperm whale or blue whale and make it much more territorial, especially during breeding season. Or the females during calving season. The ships sail through the wrong 'territory' and get smashed to splinters. They might even have a boney ridge along their head to allow for ramming, like big horn sheep. [Answer] The answer is coral. These tiny creatures form a hard barrier that, if it's hit by a ship, it can take it down. [Answer] I propose something like [the mega-creature described in another answer](https://worldbuilding.stackexchange.com/a/324/14888), in either of these two life stages: > > Stage 4: Big Grazer > > > Hundreds of meters wide the creature munches its way through the > floating seaweed leaving a cleared trail behind it and consuming > anything smaller that is foolish enough to get in its way. > > > Stage 5: Sessile > > > As the creature grows larger and slower the seaweed is no longer able > to sustain it, movement uses more energy than it gains. It sinks down > towards the deeper ocean and goes quiet, camouflaging itself in the > deep. Mostly it hibernates waiting for Grazers or Larger to pass > above, when one does massive tentacles shoot out and drag them down > into its waiting maw. > > > The Sessile form would have an interesting effect in that the area > above it would have few grazers, letting the smaller creatures grow > and the seaweed populate in fertile abundance - until the smaller > creatures grew large enough to be worth eating. This abundance would > tempt more grazers into the area, only for them to be consumed in > turn. > > > I like the sessile adult stage best. It could be driven up from the depths by volcanic activity; you can reread some Iain M. Banks to get in the mood for writing those passages. [The Great Meteor Hotspot](https://en.wikipedia.org/wiki/New_England_hotspot) might be within handwave distance of the right course, though it's probably too close to waters well known by Europeans of the time. It might be better to cook up a brand-new hotspot that's a little more considerate of the author's needs. **Another option:** If something like a stray [elasmosaurus](https://en.wikipedia.org/wiki/Elasmosaurus) started hanging around and snapping up anybody it could grab off the deck or out of the rigging, a steadily diminishing crew might struggle for days or weeks to keep the ship functioning and get it back to land. If a storm came up and they couldn't steer effectively or take in any sails, that might be the end of them. Or they could wander far off course and wreck on any number of small uninhabited islands. Tragically, carracks seem to have had a modern rudder they could jury rig to work from belowdecks, rather than a [steering oar](https://en.wikipedia.org/wiki/Steering_oar). Resourceful sailors could spend a lot of pages sneaking up on deck to rig an improvised control system for a steering oar, and even then it would be prone to catastrophic failure under the torsional stress of a major dramatic climax. [Answer] The obvious answer is one or more whales. There is no point in imagining anything more exotic. For thousands of years **EVERY** human vessel which sailed large distances was totally at the mercy of every large whale they passed close by. Only in recent centuries have the sizes and strengths (and other anti sinking factors like waterproof bulkheads) of ships increased so that a larger and larger proportion of major ocean going ships were whale proof. Fortunately for human sailors, many thousands of whales watched with only mild interest the fragile seagoing rafts, canoes, boats, and ships go by for every one who decided for some reason to attack, or was hit by the ship. Even today sailboats traveling long distances, and not much smaller than many early ocean crossing ships, sometimes run into or are rammed by cetaceans much smaller than the great whales and sink. For example, puny little orcas and pilot whales have sunk sailboats. boats have even been sunk by the even punier great white sharks. Right now I am working on a list of ships (not sailboats, ships) sunk due to running into or being attacked by large whales, which on 02/13/2016 has more than ten examples from the *Charming Sally* in 1738 to the *Lizzie S. Sorenson* in 1910. And that is not including various online claims that the great Mocha Dick sank varying numbers of ships in the first half of the 19th century. All of those ships were built much sturdier than the 15th century ships of Columbus, so Columbus's ship would not have been strong enough to survive whale impacts. Of course most ships which were attacked and sunk by whales were whaling ships actively attacking whales when they were sunk, and there is no evidence that Columbus carried equipment for whaling. So we can simply assume that the *Santa Maria* ran into a whale sleeping or resting at the surface, perhaps at night, and was damaged badly enough to sink. Of course Columbus had three ships on his first voyage, and you would want to sink them all without survivors for your scenario. (Unless the survivors returned home and without Columbus to insist on it nobody bothered to send another expedition) So you would want a pod of large whales resting or sleeping at the surface, and all three ships, the *Nina*, the *Pinta*, and the *Santa Maria*, smash into them almost at the same time. Some of the crew might launch their boats, but if Columbus and the other captains die the task of navigating a thousand miles or more back to Europe fast enough to avoid dying of thirst and starvation might be impossible. Or the surviving whales could be angered at a seeming attack and lash back and smash the ships some more so that any which were not already sinking are doomed to sink after the attack, and also smash any boats which may be launched. So the point could be that the destiny of mankind was determined by the decision of a pod of whales about which identical patch of ocean to rest in that night. If you want an even more obvious answer, have a "butterfly effect" change the course of a hurricane to intersect and sink the small fleet of Columbus. [Answer] A large, realistic sea creature able to tear down a ship 35-45 meters in length. You might want to read some detail about: # [Moby Dick](https://en.wikipedia.org/wiki/Moby-Dick) a sperm whale (fictional) that destroyed a vessel and severed the leg of the captain. # [An Angry Blue Whale](https://en.wikipedia.org/wiki/Blue_whale) the largest creature ever to adorn the evolutionary tree of earth (as far as we know). An angry full grown individual (or a mating couple) can easily destroy a 15th century ship. # [Megalodon](https://en.wikipedia.org/wiki/Megalodon) the baddest thing you could ever come across in your worst nightmares! They went extinct some 20 million years ago, but it wouldn't hurt to say a small population managed to survive. A single of these prehistoric sharks was more than capable of destroying a 15th century vessel and more! [Answer] My answer: a hyperadvanced Native American civilization based in Eastern America with underwater cities. --- Hundreds of years previously, they had had many of the same culturistic details of many Native American tribes actually discovered, but one year, someone gave birth to a would-be philosopher. His ideas included civilization, urbanization, and many other aspects of our life today. He also supported the environment like most other Native Americans. He wanted to build coast-line environment-friendly cities, and tunnels to spherical cities underwater. (He also discovered the creation of glass by melting sand.) He got many supporters by appealing to their eco-friendly and religious culture, and a century later, they evolved into an amphibious society with people living in both underwater and grounded cities. --- They learn somehow1 that the Europeans will come over with their ships and ruin their environment by colonizing it. When they hear that Columbus is sailing the ocean, they send a military sub painted like a large fish out to destroy the ship. It sends a rocket through the water, Columbus' ship explodes with no survivors, and everyone lived happily ever after. >:) --- 1: I have not come up with this yet, please suggest in comments. [Answer] **Red tide**. [](https://i.stack.imgur.com/3afFi.jpg) <https://mycbs4.com/news/local/red-tide-killing-marine-life-in-florida> Red tide is caused by a bloom of microscopic creatures called dinoflagellates. They produce a toxin which kills everything in the water that cannot escape; mostly smaller fish but also some larger. Red tide can also put toxins into the air - it causes a strange spastic cough as though you had been pepper sprayed. It makes sense that water breathers would die, but I wonder if the aerosol toxin accounts for the deaths of air breathers like manatees and dolphins. In this scenario, there is a bloom of dinoflagellates at sea around the ship. I could imagine a ship caught in the doldrums and the bloom happens around them, perhaps triggered by a distant sandstorm and iron enrichment of the water or some undersea upheaval. First, dead fish come to the surface around them, then dead dolphins and whales. The sailors begin to cough. The first mate's parrot dies. The men make masks soaked with rum and light fires on deck to try to drive off the bad air, but the bloom gets worse and worse. A group of sailors sets out in the boat to try to row clear of the bloom but are not even out of sight before they are overcome; the toxins are even worse down on the water. It is a slow, bad way to die. The ship itself is fine. It is found adrift some years later. The skeletons of the crew have long since been washed off the deck by storms. A breeding population of mice survived in their refuges and emerged to thrive eating the ships stores. The captain's log describes what happened but only in fragments, most of its paper having gone to make mouse nests. The other survivor is the ship's cat, who cashed in several of her 9 but had a couple left. [Answer] > > Essex was an American whaler from Nantucket, Massachusetts, which was launched in 1799. In 1820, while at sea in the southern Pacific Ocean under the command of Captain George Pollard Jr., **she was attacked and sunk by a sperm whale.** > > > You should read [the Wiki entry for that](https://en.wikipedia.org/wiki/Essex_(whaleship)). The depiction of the attack is quite detailed. And about this constraint: > > It was a creature that no one had ever seen before, and no one lived to tell the tale of its existence. > > > This is how books at the time of Columbus pictured whales. Most people going to the new world would never have seen a whale before:  [Answer] ## Leviathan Another slightly out of the box answer. The biblical Leviathan would fit the bill. I have no idea what this animal would look like, but it sounds pretty terrifying: <https://www.biblegateway.com/passage/?search=Job+41%3A1-34&version=ESV> > > Job 41 - English Standard Version (ESV) > > > 1 “Can you draw out Leviathan with a fishhook > > or press down his tongue with a cord? > > > 2 Can you put a rope in his nose > > or pierce his jaw with a hook? > > > 3 Will he make many pleas to you? > > Will he speak to you soft words? > > > 4 Will he make a covenant with you > > to take him for your servant forever? > > > 5 Will you play with him as with a bird, > > or will you put him on a leash for your girls? > > > 6 Will traders bargain over him? > > Will they divide him up among the merchants? > > > 7 Can you fill his skin with harpoons > > or his head with fishing spears? > > > 8 Lay your hands on him; > > remember the battle—you will not do it again! > > > 9 Behold, the hope of a man is false; > > he is laid low even at the sight of him. > > > 10 No one is so fierce that he dares to stir him up. > > Who then is he who can stand before me? > > > 11 Who has first given to me, that I should repay him? > > Whatever is under the whole heaven is mine. > > > 12 “I will not keep silence concerning his limbs, > > or his mighty strength, or his goodly frame. > > > 13 Who can strip off his outer garment? > > Who would come near him with a bridle? > > > 14 Who can open the doors of his face? > > Around his teeth is terror. > > > 15 His back is made of[d] rows of shields, > > shut up closely as with a seal. > > > 16 One is so near to another > > that no air can come between them. > > > 17 They are joined one to another; > > they clasp each other and cannot be separated. > > > 18 His sneezings flash forth light, > > and his eyes are like the eyelids of the dawn. > > > 19 Out of his mouth go flaming torches; > > sparks of fire leap forth. > > > 20 Out of his nostrils comes forth smoke, > > as from a boiling pot and burning rushes. > > > 21 His breath kindles coals, > > and a flame comes forth from his mouth. > > > 22 In his neck abides strength, > > and terror dances before him. > > > 23 The folds of his flesh stick together, > > firmly cast on him and immovable. > > > 24 His heart is hard as a stone, > > hard as the lower millstone. > > > 25 When he raises himself up the mighty are afraid; > > at the crashing they are beside themselves. > > > 26 Though the sword reaches him, it does not avail, > > nor the spear, the dart, or the javelin. > > > 27 He counts iron as straw, > > and bronze as rotten wood. > > > 28 The arrow cannot make him flee; > > for him sling stones are turned to stubble. > > > 29 Clubs are counted as stubble; > > he laughs at the rattle of javelins. > > > 30 His underparts are like sharp potsherds; > > he spreads himself like a threshing sledge on the mire. > > > 31 He makes the deep boil like a pot; > > he makes the sea like a pot of ointment. > > > 32 Behind him he leaves a shining wake; > > one would think the deep to be white-haired. > > > 33 On earth there is not his like, > > a creature without fear. > > > 34 He sees everything that is high; > > he is king over all the sons of pride.” > > > [Answer] In *[March to the Stars](https://www.baen.com/march-to-the-stars.html)*, John Ringo and David Weber posit a 50-meter fish, similar to a stonefish. It starts its attack by opening its huge mouth; this creates a suction that can stop a moving ship: > > The opening was at least twenty meters across, a yawning cavern in the abruptly surfacing snout of a piscine easily as long as *Sea Skimmer* herself. [The giant predator was an ambush hunter](https://www.baen.com/Chapters/0743435621/0743435621.htm), like the terrestrial stonefish, and the snap-opening of its tooth-filled maw created a low-level vacuum that literally stopped the ship in her tracks. > > > Unless stopped, it will proceed to bite the ship, breaking the ship in half, and then suck down the crew. [Answer] The creatures that destroyed the ships could be large plants capable of absorping almost all incoming sunlight. The plants could also create hydrogen gas to float high, similar to a tree. It could also control its altitude by condensing water vapour into its body, or by releasing the water, like a reversed swim-bladder. The way it would destroy the ships could be by drifting down, grabbing the ships, and bringing them back up to the sky to play with, or for some other strange reason ]

[Question] [ I'm looking for something that would prevent humans being able to establish the use of satellites on an alien planet, but also would not prevent humans from living on the planet, or life developing on that planet. Humans must also be able to arrive onto and leave the planet, not necessarily at any point in time, but have the availability to do it at least on occasion (i.e. they're not stranded on the planet). It's not absolutely necessary that satellites cannot be physically in orbit, but rather there could be something that affects how the satellites work, meaning that they cannot reliably be used for transmitting information. I did think of solar flares as a method of disruption, but as far as I'm aware having solar flares often and strong enough that it would consistently disrupt satellite communication would require the planet to be orbiting (or close to) a star unstable enough that life could not reliably reside there, though I may be wrong. [Answer] # Have a very wide ring If you have a ring around your planet, it will be above the equator of it. This means that if it is sufficiently wide, every possible reasonable (as in cost, orbital velocity, distance to atmosphere) orbit will pass through it. Now unlike asteroid belts, rings are made up of lots of tiny (1/2 mm to meters) rocks, bits of ice, and dust. As anyone will tell you, it is a bad idea to walk, or even drive through a rock/sand/dust-fall if there is even such a thing. By the same logic, you don't want to have a satellite going through a ring-system. [Answer] There is increasing concern about space junk threatening our own satellites. By space junk I mean pieces of metal in orbit that can hit and disable satellites. The space debris scene in the movie Gravity is really well done, I thought. <https://www.youtube.com/watch?v=prlIhY3e04k> It has been suggested that a technologically outclassed enemy like North Korea could level the playing field by shooting payloads full of gravel into orbit and scouring down all the satellites. If a planet had a lot of orbiting debris, it would be more difficult to place satellites. Maybe space debris in orbit is a result of a prior event like a war (which would make for cool writing opportunities as regards the exact nature of the debris). Maybe volcanic activity launches material into orbit periodically. Maybe satellites in this scenario would need something like the AEGIS system to target and deflect incoming debris. The debris is small and comes fast but should be really obvious to radar. AEGIS satellite shotguns could shoot plastic cased mercury shot - mercury for the mass and because once the plastic disintegrates in the hard UV of space, the mercury will sublimate to molecules and not itself pose a threat. [Answer] [Binary planets](https://en.wikipedia.org/wiki/Double_planet)! The gravitational fluctuation of two equal planet sized objects closely orbiting each other would make a stable satellite orbit near either planet pretty much impossible as the satellite would experience shifting amounts of gravity from the other planet, getting flung either away from or into the planet. You should still be able to launch from/land at either planet if you quickly move far away enough from the planets. It probably wouldn't be a very comfortable place to live in as the gravitational tug of war would make both planets quite tectonically active leading to lots of volcanic eruptions etc. but it could be habitable. In fact, [earthlike binary planets seem quite possible](https://phys.org/news/2014-12-binary-terrestrial-planets.html). Also, it would be cool as hell. Edit: After some more research it seems that the planets would [tidally lock and circularize their orbits over time,](https://www.physicsforums.com/threads/binary-planets.56303/) as this is happening they would experience shifting amounts of gravitational pull, influencing tectonics and making stable satellite orbits around one of the planets extremely difficult. This gravitational "drag" also causes the circularization. When the orbits have become circular and the planets tidally locked geosynchronous satellites might become a possibility. After all, if the planets are tidally locked in a circular orbit a geosynchronous satellite would have a constant distance to both objects. This does ignore the influence of whatever star they are both orbiting around, the star's gravitational influence might prevent proper circularization. So, the difficulty of maintaining satellites is going to depend a lot on the eccentricity of the orbits. As to how long it takes for circularization to occur and if that time span is long enough for the planet to become suitable to life before the orbits are circular, I have no idea. [Answer] The planet could have wildly inconsistent gravity. Gravity on Earth is non uniform, though it's hard to tell because of the variations are slight. [](https://i.stack.imgur.com/uiGqM.jpg) But if this planet had a large super dense mass (from a foreign body impact?) in one area then you could have a spot where the gravity is much higher than the rest of the planet. This would affect satellites in two ways: 1. Orbits would be hard because the higher gravity would pull the satellite off course and degrade the orbit rapidly. 2. The atmosphere would be pulled in very tight over the anomaly, and balloon out elsewhere. The satellite passing through the expanded atmosphere would experience drag and have its orbit degraded. [Answer] AndyD273 has half the answer. Consider the case of being very difficult to orbit the Moon (Shadow1024 posted quotes in his answer, below): close orbits are unstable because the body is lumpy, which is the case Andy shows. But more distant orbits won’t work either [because such a body would be grabbed by the Earth](https://en.wikipedia.org/wiki/Hill_sphere).  From the illustration you can see that the highest possible orbit is bounded by L1 and L2. So, make your habitable world a moon of a gas giant, with a similar situation. [Answer] Have we ruled out permanent, pervasive weather conditions? If the planet was wrapped in constant high-energy storms and if the upper layers were full of light-refracting ice crystals and radio-disruptive discharges, the colonists could launch as many satellites as they wanted to. They just couldn't ever communicate with them (either by radio or laser), once they were launched. A satellite that you can't talk to is... just a pretty light in the sky not even a pretty light in the sky. It's just gone, up there above the clouds. [Answer] Adding some detail to suggestions already above. 1) Van Allen radiation belts. The planet's magnetic field is of a strength that it's Van Allen belts are particularly hostile. Not enough to be fatal to humans on a ship passing through down to the surface and then off-planet, but enough that after a few hours in orbit any satellite would become disabled by energetic particles, and there's so much radio "noise" that signals would be lost in the background. Fun addition: you can have a plan to "drain" the belts as part of the story, so they can have satellites again, or that a solar storm blows away the belts temporarily either as a one-time event or a regular occurrence on a long time scale. 2) A wickedly active ionosphere. Energized particles (through solar, geomagnetic, or huge lightning storms) in the upper atmosphere block all radio communication back to the ground. You can launch a satellite, but any signal you send up bounces back (and vice versa), so you can't talk to it. Between clouds, aurora, and lightning, optical (laser) communications to space are horked too. Fun possibility with such a reflective ionosphere is that you can possibly bounce terrestrial radio signals all over the planet... HAM type radio operators could talk and listen to the whole world. [Answer] Meteor showers. Really, really intense meteor showers. Suppose that several plumes of small rocks are orbiting the same star as this planet in highly eccentric orbits, containing an extremely large number of such rocks, collectively the mass of a planet or more broken into tiny bits. Each time the habitable planet's orbit intersects the orbits of one of these plumes, the rocks light up the entire night sky like the finale of a fireworks show (and would light up the day sky too if the star weren't so bright), unlike the relatively tame meteor showers we get on Earth. Anything in the vicinity of the planet above the upper atmosphere at that time is either perforated by the accompanying dust or destroyed completely by collision with one of the larger pieces. In between meteor showers, spaceships can come and go safely. Just be careful not to get caught in one, and forget about parking anything in orbit for any extended period of time. If the planet's orbit is close to the periastron of the rocks, they'll catch up to it from behind at high speed, less than the difference between the planet's orbital speed and escape velocity from the star, but not necessarily much less. If the planet is near the apastron of the rocks, it will plow through them while they are relatively stationary. At some point in between, the rocks hit the night side of the planet on the way in toward the star and the day side on the way out. Life may even be a little precarious on this planet, as mixed in with these billions of tiny projectiles that burn up in the atmosphere there are a few rocks large enough to make it to the surface, some large enough to create large craters. The really big ones are few and far enough between, however, that the local biome has always recovered from these meteor strikes, and there's a reasonable opportunity to establish a human colony with the wherewithal to detect and deflect any rock large enough to be a threat to the colony's existence. [Answer] Solution for a Killsat Planet: the Moon like situation. Quoting NASA: > > "High-altitude circular orbits around the Moon are unstable," says Todd A. Ely, senior engineer for guidance, navigation, and control at NASA's Jet Propulsion Laboratory. "Put a satellite into a circular lunar orbit above an altitude of about 750 miles (1200 km) and it'll either crash into the lunar surface or it'll be flung away from the Moon altogether in a hyperbolic orbit." Depending on the specific orbit, this can happen fast: within tens of days. > Why? Earth is responsible. The gravity of massive Earth only 240,000 miles (400,000 km) from the Moon constantly tugs on lunar satellites. For a lunar orbit higher than 750 miles, Earth's pull is actually strong enough to whisk a spacecraft out of the game. > <https://science.nasa.gov/science-news/science-at-nasa/2006/30nov_highorbit> > > > And: > > "Lunar mascons make most low lunar orbits unstable," says Konopliv. As a satellite passes 50 or 60 miles overhead, the mascons pull it forward, back, left, right, or down, the exact direction and magnitude of the tugging depends on the satellite's trajectory. Absent any periodic boosts from onboard rockets to correct the orbit, most satellites released into low lunar orbits (under about 60 miles or 100 km) will eventually crash into the Moon. PFS-2 released by Apollo 16 was simply a dramatic worst-case example. But even its longer-lived predecessor PFS-1 (released by Apollo 15) literally bit the dust in January 1973 after less than a year and a half. > <https://science.nasa.gov/science-news/science-at-nasa/2006/06nov_loworbit> > > > To make it perfect: -Make the planet a bit heavier and with a bit denser atmosphere... Just to put extra effort on launching anything and increase any low orbit decay -To get properly heavy body in vicinity - put the planet around a tiny, dim red dwarf. (just don't forget about tidal lock, but it's mostly a story thing and not survivalibity issue) -Oh... Red dwarfs tend to be a flare stars... I should not matter much for a planet protected with a thick atmosphere, right? ;) [Answer] The human-tolerable atmosphere is incredibly thin--they wouldn't even dream of building skyscrapers due to those shifting, capricious places on the planet where it is practically non-existent (life in that environment is a whole story in itself! ). Above the super thin breathable air are layers of electrical charge diversity that for some reason causes continual high-volume lightning strikes to occur between those layers of the upper atmosphere while only rarely discharging down to the planet surface. On this planet they use spacecraft with electrical shielding technology to get through the atmosphere, the people love one-story buildings with elaborate underground living areas, and the night shows are appreciated like a lovely sunrise or sunset. And they don't send communication satellites into orbit. [Answer] Atmospheric drag. The planet could have such a large atmosphere, or be contained inside a larger cloud of gas and/or dust, such that all reasonable orbits around said planet would be non-vacuum. This would cause satellites to de-orbit on their own within a very short time due to drag, but not prevent active ships from traveling through it (albeit expensively). A satellite is by definition only kept in it's orbit by gravity/speed at launch. If it contains equipment to change it's orbit or actively maintain it, it's a ship. Remember. Space =/= Vacuum. [Answer] How about very strong solar radiation that renders satellites dead electrically in such a short period of time (matter of minutes or hours) that it's not worth even trying to launch them? [Answer] Having worked in military satellite communications for about a decade I would have to say that you need a source of interference in the same range as whatever satellites you have that you can put up. On our own world certain entities use certain "bands" to communicate back and forth. A radio source either natural or man made compromising your satellite's transmit and/or receive will make most communications signals unusable. However if the planet is to remain unable to communicate the interference must be very broad and something that cannot be "fixed" easily. Without knowing whether the situation would be permanent or if it starts at some point and maybe ends at another I cannot go any further. Let me know because my husband was a military communications instructor and I can get him involved to find you a solution. [Answer] I'm not very science-minded, a lot of the more detailed stuff just escapes me, but maybe multiple moons in low orbit would throw off the orbit of any satellites. This wouldn't disrupt the signal but would make it impossible for them to stay in orbit. Particularly if the moons were close together in their orbit which would make the satellites change from the orbit of the planet to the orbit of one moon to the orbit of the other moon, possibly even catapulting back into space. ]

[Question] [ I am thinking of, yes, a simple story with intelligent dinosaurs, but I am not interested (And I sincerely prefer) that they are not sufficiently advanced in my history to be comparable to modern humans, at most I imagine them similar to the humans of the Neolithic. BUT, if it is in any way possible that they could be more advanced without leaving a trace in the world I would like to know. If, on the contrary, they need to be even more primitive than Neolithic humans in order to not leave traces of their existence, I will understand, I just want to know. What I want is to make it almost impossible to prove that they existed, at least for now. Some details are; In my story there are not several species of intelligent dinos, only some variations of troodons. I imagine them only having 4 or 5 towns or cities in an area of ​​only 40 km. They haven't "spread" around the world or anything. They are basically the first "cities" in the world. I imagine them having primitive wood and stone weapons, art made of wood, amber, and maybe stone, and a couple of religions. I imagine them having a social leader (a king?) And a religious leader, only these would wear clothes and it would only be partial. Maybe the warriors or something could wear ornaments made with their own feathers or those of other species of dinosaurs. [Answer] Are there likely to be some traces? Some tools? Some evidence of culture and burial rites? Maybe, and maybe not. Depends upon where the intelligent dinos lives, and what happened to that rather small place afterward. 65 million years is a mind-bendingly long time. And a lot can happen in that time. * The Pyramids have been around for 5,000 years. You're looking at 13,000 *times* longer, enough for half the volume of hard granite to be weathered away. It will be much smaller then. * Niagara Falls erodes roughly 1m (3 ft) annually. 65 million years is much longer than needed for it to erode past the Canadian Shield and all the way to the Pacific Ocean...were the river long enough. * The mighty Himalaya Mountains are only 50 million years old. But let's just look at the BIG NEWS events. * Ice age glaciation occurs every 40,000-100,000 years. You're looking at around a *thousand* ice ages, each scouring the north and south. * Tsunamis occur about twice each year. You're looking at over a hundred million tsunamis scouring clean everything at sea level outside the glacier zone. * Tropical cyclones (hurricanes) form around 80 times each year. That's over five *billion* ravaging the tropics. * Magnitude 8+ earthquakes happen roughly one each year. Magnitude 9 earthquakes are estimated at about 1 per century. That's still over half a million. * A volcano erupts about once each *week*. Over three *billion* eruptions, including some mighty big ones. Cities near the sea will be smashed, flooded, buried in sediment, decayed in swamps, eroded and exposed, overgrown by jungle, scoured by ice, and re-buried...many times. Cities in the hills will wash away with those hills. (Look what the Grand Canyon has done in only 5-6 million years.) If an advanced culture left a cache sealed deep inside a reasonably stable, impermeable strata, we might find the cache (those pesky earthquakes and volcanoes might destroy the cache). But we're unlikely to find anything else. And the intelligent dinos in this question lack that capability. [Answer] **You can basically do what you want!** You say your civilization is not spread around a very large area. (40 km across) You just have to place this civilization on a part of land that is not suitable to carry fossils and be excavated today. To help you choose a place that suits your story, maybe [This interactive map will help](https://dinosaurpictures.org/ancient-earth#120) If you want to make extra sure, give them a burial ritual where their remains are burned and their belongings crushed to dust on what was then the shoreline to be washed into the sea. [Answer] **Very primitive** As mentioned in another post, there are lots of relics that are still found of humans. Although dinosaurs have the advantage of being much older, we are still finding well preserved fossils in certain strata of the earth. Any tool can become stuck in a strata, or even just leave an imprint, which will have historians break their heads how this is possible. It might be possible to have some tools in area's where preservation is unlikely (not being covered quickly by earth, amber or whatever). If there are few tools enough, it might be put down to a mistake in dating, or that the preservation makes it look older than it probably is. What is possible is an advanced social structure. Social structures can be inferred by how the dinosaurs are located by historians, but this is unlikely. There aren't many fossils of even the recent dinosaurs. The dinosaurs that are found require something to happen for it to be well preserved. This often means that a lot of context is obliterated, making inferring social structures very difficult if not impossible. A social structure and no tools also makes more sense for dinosaurs. There are too few that would be able to build and use tools due to their physiology. Humans (and primates) are uniquely build for this. There are a few other species who use tools, like dolphins, but they mostly use the environment directly. These tools would either disintegrate or be unidentifiable as a tool. A Diplodocus ripping off a branch and using it to fend off an enemy would be difficult to see after so many years. A social structure can involve anything from gathering food for your fellows to complex grieving rituals. Time and bad preservation will likely remove all of the evidence. No agriculture would be possible though. Besides the difficulty of them sowing and tending crops, these area's might be seen more easily due to the traces in the sediment. [Answer] **Not Necessarily Primitive, But Certainly *Different*** One of the universals of human culture is tool making. (This is different from tool using, which as we know many animals do.) Shaping stones sufficiently to make them into tools leaves an essentially permanent record of not only the tools' existence, but also a record of the culture that made them. This in turn leaves a record of the intelligence of the species as a whole. In other words, we don't just see evidence of a handful of ancient cities and absolutely nothing from other humans. All of these activities will leave evidences that can last, essentially indefinitely. Looking at the fossil record from the saurian age, we find not only fossilised bones, but also eggs, nesting sites, some wood, amber, and even impressions of feathers and skin texture. If your saurians are engaging in tool making and any kind of construction or intentional rearrangement of the natural environment, they're going to leave a trace. This means your intelligent saurians have to be quite different in their cultural basis. If you want for their civilisation and their cultures to remain entirely without trace, then it's quite simple: *culture must not be material in nature*. Their culture must be entirely oral (if they speak and use language) and entirely cognitive in nature. The only things that can ever be produced by these kinds of cultures is aural ephemera: stories, legends, myths. **How to do this:** They'd basically have to be wired in the brain to balance intelligence with intense acuriosity; the ability to construct complex and deep levels of cognitive structure without the desire to manifest those structures in the physical world; an entirely spiritual understanding of self, community, and world completely divorced from the physical world around them. They could construct extremely complex and time deep societies without ever having to shape a single stone or piece of wood to do it. They'll be helped by already being excellent hunters and fighters. Their bodies already provide them with all the tools they need to survive: tooth and claw. They don't need to farm, they don't need to make clubs or swords. They just need community in which to evolve this wonderful and fantastic culture! [Answer] # ***Human Blindness and Scientific assumptions:*** Every so often, people find strange bits of metal and ceramic-like material in stones. Odd regular shapes turn up in long, strung-out geological arrangements like roads. Jewel-like stone shells can be found in museums around the world - they're beautiful, if you care to go the the Smithsonian and take a look. Does that mean we've announced to the world that there is an ancient Reptoid civilization? Okay, yes, some people have. No one takes it seriously. They assume things are natural, or fossils, or strange geological formations. Ancient machines people insist must be computers turn up, but there is always an alternative explanation. Nature does tend to produce things that take on extraordinary repetition and apparent organization. Folks assume things come from contamination of fossil sites. In a world where there had been an ancient (***REALLY*** ancient) civilization, almost everything would have disintegrated from the original form. We're talking orders of magnitude longer than the remains of stone tools from early man. Fossils of worn artifacts might turn up, but that would just mean people would identify these as a certain genus of plant fossil, or a unique erosion pattern. People would find things that defy explanation - and throw them in the discard pile because they assumed the overseer dropped a broken tool. Archeologists today are re-excavating the midden heaps from old archaeological expeditions because the early archaeologists made broad assumptions about what was important. There would certainly be a few visionaries and crackpots that would announce to the world the ruins of ancient cities, but the experts would point out there were similar formations near the mouths of every river from the time, and attribute it to a primitive form of tree growing on mineral deposits in river deltas (now extinct). The cranium of that iguanodon relative was really big, and you think it could have had opposable fingers? Well, those are vocalization chambers, and they used those manipulators to pick fruit, of course. So while there might very well be some evidence of an ancient civilization, no one would take it seriously and anyone who did would be laughed out of scientific circles. After all, those weird little shells are ALL OVER the world, and that type of shell always had a really high aluminium content in it. [Answer] If your entire dino civilization was localized to a small area that was right underneath the Chixhulub impactor, then they could have been relatively advanced and almost all evidence would have been obliterated by the impact. Unfortunately, per all the paleomap reconstructions I've seen, there were no large landmasses at the impact site around that time; what would eventually become the Yucatan peninsula wouldn't emerge until something like 40 million years later. You could maybe handwave that away by having an island or island chain in that area, which would also help explain why the civilization was localized in the first place. [Answer] If your civilisation is restricted to a small area, and won't leave any chemical record widely around the earth it is virtually impossible that they would ever be discovered. Fosilisation, for example, is incredibly rare and most of earth's surface is actually from after about 3m years ago. Most of my information comes from [here](https://en.wikipedia.org/wiki/Silurian_hypothesis#:%7E:text=The%20Silurian%20hypothesis%20is%20a,perhaps%20several%20million%20years%20ago.) But this is a distillation of the information in: Gavin A. Schmidt, Adam Frank. [The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? (pdf)](https://arxiv.org/pdf/1804.03748.pdf) International Journal of Astrobiology, 2018; 1 DOI: 10.1017/S1473550418000095. Or see a summary [here](https://www.sciencedaily.com/releases/2018/04/180416124327.htm) To actually answer your question, you don't have to do anything, you could actually have a widely distributed industrial civilization almost as advanced as our own, and we probably still wouldn't detect it after 65 million years. [Answer] **Any level of advancement, if the location was somewhere hard to access today** Expanding on my comment, because no other answer has addressed this. We would not have stumbled across evidence of an ancient civilization if it was under water (think - there were probably villages on the Bering land bridge during the last ice age, but there's no chance we'd discover them). We also wouldn't stumble across archaeological evidence if it was buried under a deep glacier in Greenland or Antarctica. Your civilization wouldn't have to be confined to 40km^2 if it were on a "lost continent". I mean, they could have cars and trucks down there. Hiding it in Antarctica might be a good idea for your plot, so you can have the evidence discovered by researchers in the modern day (as opposed to "stumbled across" in the 19th century). [Answer] See these stone tools in an museum exhibit: [](https://i.stack.imgur.com/OOaUT.jpg) These have survived to modern day. So none of these things can be made in your civilisation. No arrow heads. No spear heads. No morter and pestle. No cups. No jewellery. No axes. No knives. No saws. Basically you cant enter the stone age. You can make things out of wood, but you wont have any tools to work that wood into decent shapes. You'll need to find branches close in shape to what you need and then "that'll do" it. This does leave some interesting opportunities for building a society: You will be able to weave things out of reeds, strap thick branches into a structure with vines as lashings, and cover roofs with dried grasses. Simple huts are very plausible. You may be able to have rammed earth walls on your structures too, for a bit more weather resistance or for indoor fireplaces. I'm assuming theres a good chance this land will get flooded many times over the next millions years to erode the walls. You'll be able to dig irrigation channels to fertile farmland. Probably cant have viaducts or dams without risking leaving a trace, dams may leave water level hints. Paths would get flattened by use and become roads. Simple wooden sleds for carrying loads can be used. Wooden wheels are possible and unlikely to survive. [Answer] ## Many tribal societies today will have no archaeological record in a thousand years, much less millions of years We don't really know how far back our own civilization goes because evidence of early man is so degraded and hard to interpret. There are many primitive technologies that we only know about because modern tribal societies make them, but they have no way of lasting for very long unless preserved by a very rare and well timed fossilization event. Such events are so rare that you are more likely than not to have an entire civilization rise and fall without it happening once. **Tool Making:** The beginning of our own tool record begins with a technology called stone napping: a technique of chipping stones against each other to make a sharp edge, but we have no clue how long man was making un-napped stone tools or non-stone tools before that. Napping is easy to identify, even if a tool is somewhat degraded because it is so clearly unnatural, but it takes a lot of skill and dexterity to make. When you look at primitive civilizations today, many of them prefer ground stone tools because they are easier to make, but they also closely resemble the effects of natural weathering; so, when we find ground stone tools, we can rarely make conclusive statements about if they are tools or just random sharp rocks. If your dinosaures don't quite have human levels of dexterity, they may be stuck making ground stone tools indefinitely, even if they are just as smart as humans. These examples of ground stone tools would be almost impossible to identify if they were not found alongside other signs of civilization, and these are not nearly as old. [](https://i.stack.imgur.com/YfcSY.png) Then there is fire-sharpened wood. A stick can be sharpened and hardened by burning the end in a fire and grinding the tip into a point. Tribal societies today often make their spears and arrows this way and they are nearly as sharp and hard as stone, but since wood rarely lasts for over a couple of centuries, a civilization could make 10s of thousands of such tools and not a single one would last anywhere near as long as the time frame you are asking about. Similarly, your civilization could practice weaving, textile making, leather working, and various other crafts involving organic materials and no one would know. [](https://i.stack.imgur.com/knLZp.png) It is even possible your dinosaurs could discover iron working since iron tools rarely last much longer than wooden ones, but if they do this, they will probably also discover ceramics. You want to avoid them having ceramics since this will be the most likely thing to survive that long. **Housing:** There are a lot of ways to make a house that don't last long. Compressed Earth, wood, reeds, hide, etc are all used as building materials in primitive societies today and have basically no chance of lasting for very long. Now let's say your dinos are a bit more advanced than this and decide to make stacked stone structures. These tend to fall apart and just look like unusually dense concentrations of buried rock after a while. Since many birds make nests out of things like stones, we could find an entire dinosaur city, and just assume it is some kind of dinosaur nesting ground that started off as just piles of stone. We'd think it's neat, but would not jump to any conclusions of particularly intelligent design. It is also possible your dinosaurs build their homes into the ground, but many uncivilized animals build burrows too: bears, snakes, frogs, meerkats, etc. So, you could likewise find an entire city of dinosaur burrows and not even consider this a sign of civilization. **Clothing:** While it is true that soft materials like skin and clothes are sometimes caught in fossil records, this is VERY rare. We have no more than a dozen or so fossiles of nearly any given dinosaur species, and very few of those have preserved any such details as skin. It took nearly 100 years of archaeology for scientists to realize dinosaurs in general where feathered animals, and that is while looking at the remains of every single dinosaur species over a period of over 200 million years. If a single species of dinosaur had a civilization that only lasted a few hundred thousand years, then the likelihood of there being a single surviving fossil showing it wearing clothes would be slim to none. [Answer] We have found dinosaur bones. Something made of stone (let alone metals) would be at least as durable as those bones. So you are limited to stuff that doesn't end up preserved or that doesn't end near those preserved dinosaurs. You can't have simple stone tools or weapons, because at least SOME dead dinosaurs should have some tools nearby, or you need a very convenient excuse why they wouldn't. You could have wooden wheels, stone/wooden houses, paper etc, as all of that will be long gone in those millions of years, while houses destroyed dinosaur bones when they shattered ... But how would you explain existence of those things when they lack stone tools needed to make them? That I do not know. If you are willing to handwave quite a lot, you can simply proclaim that those advanced settlements and surrounding area were completely wiped out by earthquakes, volcanoes or whatever else. Those bones we have found would be of dinosaurs that weren't in or near the city when disaster hit. Perhaps their spiritual folks traveling from place to place preaching about dangers of using stone ("bones of the Earth"). [Answer] **An unusual setup** is an advanced civilization which chooses to live perfectly integrated with nature. Think of "the Nox" in Stargate SG-1, but ignore the flying city. They might have "magic" powers. Your beings could use telepathy, teleportation, telekinesis for feeding, communicating, defending, hiding, healing, traveling. They can use their abilities on themselves, or on others. They can affect equally living matter, and non-living. I do not know yet if they can resurrect the dead, you have not yet decided on this matter :) Living in natural burrows or caves, and using only plants / wood for anything they need (shelter, food), they would not leave a trace even after 50 years. Remember, they do not need any stone / metal tools, since they can do everything mentally. So there is nothing to be left behind. [Answer] What is a civilisation? It's entirely plausible to have a civilisation with neither tools nor permanent records, but with a high degree of culture based on oral history and embellished legends presented by bards at periodic eisteddfodau. [Answer] "Primitive" is a loaded term, which is why it would not be used by a modern athropologist. Let's consider, rather, an extremely advanced society, one far in advance of current humanity. They live in peace, with no crime, poverty or disease. They live in harmony with nature, with no need for technology. (Perhaps they do it all via spiritual strength or psychic power, maybe it's a form of biotechnology; hard to tell) They are, essentially, living in a state of paradise: but there is nothing for future paleontologists to puzzle over. Simple answer: they can be extremely advanced and leave no trace if you're looking for the wrong thing. [Answer] More advanced than ours. After industrialisation caused CO2 levels to rise from 1200 to 2500 ppm at the end of the Jurassic, the Silurians invested in all manner of technologies to remove all Sauroprogenic effects on the environment, nanotech removing all trace of previous industrialisation and only using materials which biodegraded completely in a few centuries. This tread lightly philosophy led to their civilisation continuing to thrive for many millennia, but leave no trace. [Answer] Saurian Sapiens (to give them a semi-sciencey name) evolved in what would later become modern Africa from a creature similar to [Troodon](https://en.wikipedia.org/wiki/Troodon) Unlike humans, they never left their cradle continent to spread across the world. Their metabolisms and tolerance for different environments is significantly lower than that of humans. Consequence of their smaller body-mass and biology. Their high intelligence and social nature combined well with their omnivorous diets to increase their brain-mass. They built their society on river-deltas and coasts and their biggest challenges were the much larger predatory dinosaurs. Their numbers were never high far from their communities a matter of a couple million all told, but they did well enough for a few thousand years at a stone-age level. They had tools, homes, art and a strong tradition of history, they even developed weaving, writing and a theory of mathematics. The Chixhulub impactor killed them all. The plummeting temperatures were unsurvivable and the tsunamis wiped out their coastal towns entirely. Humanity has not found evidence of them simply because those that weren't in towns largely weren't fossilised, while the ones in the towns were destroyed wholesale and their bodies scattered or buried under tons of mud. There may be remains to be found 65 million years later. A variant therapod with an enlarged brain, hints of small stone or bone tools here and there. But without intense study, those tools are quite similar to stone age human tools. It is vanishingly unlikely that what little evidence there is will be interpreted correctly, even if they are found. [Answer] I think primitive hunter gatherer nomadic tribes (though personally I think agricultural may possible too, considering some that as far as I know is still debatable regarding its existence as myth civilization or not). Either without houses or making their houses out of animal skin with branches as support. Since I believe your dinosaur can manipulate tools, use organic materials except stone and bone as @Ash has said, except I believe some of your dinosaurs have sharp teeth or strong teeth to chew bark or the wood or branch, so I think they can craft it using their mouth. And I suggest not to use burial but use cremation, assuming your dinosaurs know how to make fire or doing corpse cannibalism or eating the different species' corpses in that society (assuming it was a multi-species or -ethnic dinosaur society) and crush the bones to ash to leave no trace. [Answer] **They need to be Pre-glassblowing** Time is the big issue, very few things can survive tens of millions of years, metals and organic materials breakdown, stone tools become degraded, even pottery suffers water damage. Fossils from that long ago are never completely intact even well preserved material suffer cracking and chemical degradation. As long as the civilization is using natural materials their existence will be contentious. Consider how few fossil bearing deposits there is as you get older in time, it is entirely possible for nothing conclusive to survive. Metals are not good enough because metals tend not to survive on their original shapes in sedimentary environments. Even pottery suffers chemical alteration which will destroy it. worse it is too soft and has no real chemical distinction so confusion for concretions or even biologicals trace is too easy. Blown glass however is a dead giveaway, smooth edges, purity, chemical stability, hardness, all favor long term preservation of glass. A glass bottle in good burial for a hundred million years will still look undeniably like a glass bottle and will not be confused for any natural glasses. Its chemistry and shape leave little room for interpretation. Now of course most glass will not survive, physical weather will destory most of it, but it only takes a few cups or jugs in fossilization like conditions to leave undeniable evidence, and preservation of glass is likely becasue it is chemically inert burial and ground water has no effect on it. Blown glass is both physically identifiable and chemically distinct from any natural glass, the removal of impurities and variety of still purposeful shapes makes it impossible to confuse with natural glasses, including biological ones. keep in mind this covers most of human history, you can even use early Roman history. Location can play a lot in this. If the center of your civilization is around a major mountain building zone most of it would be completely erased. If there was a civilization on the northern coast of India 50 million years ago we would have no idea. [Answer] Keeping them on the primitive scale you picture could work with no known evidence of their having "achieved" that. Consider all the things above about physical evidence, then consider that we might not even realize evidence existed. That doesn't apply to troodons, I suppose, but consider anything a fair deal larger would have houses, for example, on a much different scale than humans. Posthole remnants, often all that remains, would look more like circles in very old henges, if one even realized they went together because of the out-of-the-box scale. Like the recent enlargement of the scale of the Stonehenge site. Eventually realized, but... "eventually"... and archeologists are like anyone else, not wanting to have everything they do ridiculed because they dealt seriously with a workers' "campfire story" conflation (?... or was it?) of odd pieces of evidence. Could take a LONG time for serious analysis. But... in the example we have, human history, seven million years or so of differentiation was needed to reach the "a few small cities" stage and there is a lot of evidence along that time path. So that would be there. Just how much would ever be in places we would explore is the question. If it was inside a reasonably new mountain, well, even construction projects might never find it, much less notice it. (Funnily enough, the ones most likely to interpret any such evidence correctly, the "it was ancient aliens" crowd, is also the least likely to ever really want evidence to interpret.) And evidence can be misinterpreted too, giving rise to longstanding, unimpeachable beliefs that impede scientific explanation in various ways. What are two (of many) things common to people almost everywhere? One is fossils exposed by weathering, even in mountains, many of fish, thousands of feet above any known sea and far from them all too. Another is flood myths. Find a fossil fish a mile up a mountain and 500 miles from sea and a flooded earth story just makes sense. And might easily be more believable with a god as the agent since no natural event floods anything, much less the whole earth, a mile deep for the fish to get there and die. Another common myth is misshapen monsters. Ever seen some of those fossils folk find? We have common ancestors, the basic bones are all there, the heads misshapen, the proportions wrong... must be monsters and see the size??? Gods and their enemies... Even give them animalistic interpretations and all you see is monstrous animals, not normal, natural ones. It is all so easy. Hence my belief archeology might go a LONG LONG time with evidence they shoehorn into sketchy seeming explanations backed by "I'm a professional archeologist and you're the fellow who balances the IQ scale at 100." Or just shove them into a shoebox and store them to never even film for outsiders to view, much less see or handle. A fairly small-scale four-five town civilization might leave traces that no one ever put together. Then the comet hits and that's that. However, all that aside, you cannot take them much further along the scale. Let them reach a fossil fuel burning level and the fossil fuels are GONE. Never to be renewed as the activity that created them cannot happen on any meaningful scale ever again. We WOULD have noticed that and if enough were left, we would have advanced to the point where we realized a great deal had been used up. Might not have to go far along the path either because coal miners would surely have discovered enough evidence to get people thinking. It simply couldn't be missed for long, and would have been discovered long before we got going discovering our own past. (Might even have kickstarted that archeology, actually.) And we would have never reached our current place in the sun. Wouldn't worry about what came before, just curse it. By the way, it's not a pretty future for our own species if we peak and fall back. Kinda hard to go from campfires to nuclear reactors in one step. Even windmills like today's take a lot of tech advancement. So a fair ways back on the physical advancement path could probably slide under the radar pretty easily. But much more and it would start to be difficult to picture. Those fossil skeletons we find, they made it. One thinks a stone or concrete building or two or ten thousand could survive with noticeable over just as long a period would not be hard to picture either. [Answer] You can discern tribal society and civilization. Humans went through a tribal phase prior to becoming a civilization. The tribal phase was the same as Aboriginal Australia or North America prior to European colonization, tribes living in wigwams and caves. Humans only made civilizations when they had genetically selected crops that could generally provide a lot more food than wild crops, and then they can make dinosaur stone henges. Caves are awesome for preserving artefacts but they rarely last for 65 million years, unless you found some kind of special cave which hasn't turned to rock in that time. Stone tools can last that long, so any kinds of stone tools which precede a civlization by about 1 million years, and art on bones and sculptures, which span about 0.1 million, are probably the kind of technologies that would be easiest detected later. [Answer] # Everything Leaves Behind Evidence It would have to be so primitive that calling it a "civilization" wouldn't be accurate. * They can't have tools. Those show up in fossil records. * They can't have written language or art. That would show up on rocks and in caves. * They can't have burial rites. Archaeologists would find graves. * They can't have agriculture. That's easy to infer from fossils and artifacts. * They *definitely* can't have metal anything. Metals nearly exclusively exist as ores naturally, so finding a chunk of solid rusty iron is automatically suspicious. * They can't have money because that would show up in fossils even if it weren't metallic. ("Hmmmm... this T-Rex fossil appears to have 50 seashells by its pelvis. Maybe it's money or something") * They can't have permanent structures. These show up in digs. * They can't have clay or brick. Pottery shows up, even if mere fragments. * They can't have cities. Those not only depend on other technologies that would leave a trace, but they're *really* obvious in archaeological records. 65 million years is a long time, but not long enough to erase evidence of a civilization. The most you can really do without leaving evidence is talking dinosaurs with a deep oral tradition. # ... Unless ... There would need to be a god or sufficiently powerful being who can erase all evidence of dinosaur civilization, preferably one with a really good reason to do so. This is pretty handwavey, but it gets the job done. [Answer] The absence of proof of a dinosaur civilization is not proof of absence. We can look to our own civilization as our technology evolves. In our earliest artifacts, function dominates form. Ancient arrowheads are easily recognized even though the cultures that made them are distant memories, whose only existence is often only told by the same stone arrowheads. Fast forwarding today, and the smart phone whose form trumps its function. It's designed to fit easily our hand and a pocket and to be pleasing to our human esthetic sense. After 50 million years, exposed to weather, erosion, and geological forces, nothing would remain of a cell phone, or at least nothing recognizable to hint at its original nature with the organic plastics and glues, and metal and semiconductor components ground down into so much muck and gravel. The obvious object to this statement that nothing would remain is to point to our great buildings, surely they would remain and I think that there would be something remaining, especially facilities we built to withstand nuclear attack. They'll last as long as mountain ranges I expect. But this objection supposes that dinosaurs needed or wanted to buildings. We, as hairless primates, need to create our own shelters, but a sapient evolved from dinosaurs could imaginably not want artificial shelter, or might find organic based shelters more esthetically pleasing. Harry Harrison's ['West of Eden'](https://en.wikipedia.org/wiki/West_of_Eden) posits intelligent dinosaurs that excelled at biological technology, and could alter living beings to be weapons or factories. When a culture like that died out, its footprint could imaginably fade to nothing in a few thousand years. [Answer] **Even human civilization as it is now might be completely lost in deep time.** A lot of people might think of fossils as unavoidable evidence for past species/civilizations. One thing that is not generally realized is how exceedingly rare fossils are. To quote Bill Bryson in "A Brief History of Time", Chapter 21: > > Only about one bone in a billion, it is thought, ever becomes > fossilized. If that is so, it means that the complete fossil legacy of > all the Americans alive today—that's 270 million people with 206 bones > each—will only be about fifty bones, one quarter of a complete > skeleton. That's not to say of course that any of these bones will > actually be found. Bearing in mind that they can be buried anywhere > within an area of slightly over 3.6 million square miles, little of > which will ever be turned over, much less examined, it would be > something of a miracle if they were. Fossils are in every sense > vanishingly rare. > > > Combine that with tectonic subsidence, glaciation, meteor impacts, lava flows and just general erosion and in 65 million years everything our civilization was would be long-gone dust. Yes, there might be the equivalent of a granite dinosaur statue buried somewhere - finding it is a different matter. Have a look at [this article in the Atlantic](https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/) for some more perspective how deep deep time really is. An advanced industrial civilization will leave some chemical and radioactive markers in sediments, but those could be interpreted as natural processes - even nowadays, there is no guarantee scientists are not seeing some kind of vague evidence for previous advanced civilization and holding it for a natural process. I would say, you are safe to have a pretty advanced civilization; even satellites launched by it would not stay in orbit that long. [Answer] Very advanced Consider a civilisation that discovers something so terrible that they choose voluntary extinction to ensure that any future civilisation is not exposed to it. In doing so they go to considerable efforts to hide any trace that they ever existed; even things that we haven’t so far thought to look for. ]

[Question] [ In my land we have a race of human-like cyclops. The only real difference is their increased strength, and the fact they only have one eye. Would having one eye affect depth perception, and if so how can I explain a solution to this issue without using magic? [Answer] Supposedly birds (those with eyes set on the sides of their heads) compensate for monocular vision with rapid head movements, their brains stitching together images from multiple angles into one 3d image. From <http://www.ducks.org/conservation/waterfowl-research-science/a-birds-eye-view> > > Another way birds compensate for monocular vision is rapid head > movement. By moving their head rapidly from side to side, birds can > observe an object with one eye from two different angles in quick > succession. This creates a three-dimensional picture and greatly > improves depth perception. Although difficult to see in ducks, this > behavior can easily be observed in a backpedaling goose as the bird > swivels its head from side to side judging the distance, location, and > timing of its landing. > > > Your cyclopses (cyclopes?) could do the same. They could nod their head as they were going along, as if they were grooving to internal music. This would not preclude them from also grooving to internal music. Or they could sway their heads from side to side like a snake charmer. Or rotate them left to right, as if constantly saying no. There are many head motions your cyclops could make, all of which change the position of the eye and so enable 3d images. I encourage you to try them all in the presence of friends, possibly with a cyclops eye taped to your glasses. Decide which is the best fit for your world. [Answer] Despite Will's excellent answer, I feel compelled to answer myself as I had asked this question only a couple days before in [biology](https://biology.stackexchange.com/questions/62700/telling-distance-with-one-eye) and the question excited me too. Our body is built to have multiple check's in place to aid us. Think about all the people blind in one eye in the world. They all are able to easily walk and judge depth due to several checks we have in place: Focal length: If you try to look at something very close to you and then something very far away, you'll notice your vision gets a bit blurry as your eye must refocus. A single eye would be able to tell the distance of an object by judging how much it has to refocus to see an object. Prior knowledge: If you know the height of some object, you can use it relatively guess its distance and the objects around it. Relative speeds: Closer objects move faster than farther objects and this can be used to judge speed. For example, when a car is coming towards you, at a distance it seems to be going slow. However by the time it reaches you, it (visually) moves very fast. Your brain combines the change in speed and size of the object to judge its depth. Perspective: Parallel lines converge at a distance of infinity. Our brains instinctually uses this to measure depth. For example, a path narrows as it gets farther from you. Your brain automatically uses this to tell that the path is getting farther from you. There are even more ways our brain registers such things which can be found [here](https://en.wikipedia.org/wiki/Depth_perception) as Krause showed me. But... nothing is perfect. Of course a cyclops can be fooled. However, so can humans as we see with the countless optical illusions that artists often like to draw up. An interesting optical illusion is an Ames Room that I recently learned about. It tricks your depth perception and might be an interesting thing to look into. Great question! [Answer] Humans have about two dozen different methods for [judging the distance to an object](https://en.wikipedia.org/wiki/Depth_perception). Only two of them ([stereopsis](https://en.wikipedia.org/wiki/Stereopsis), the relative shift of an object against the background, and [convergence](https://en.wikipedia.org/wiki/Vergence#Convergence), the amount of inward shifting needed to center the object in both eyes' field of view) depend on having two eyes. Your cyclops has the following techniques for judging the distance to an object: * [Accomodation](https://en.wikipedia.org/wiki/Accommodation_(eye)): the amount of focal shift needed to bring the object into focus. If your cyclops has the stereotypical single huge eye, it will be far better than humans at judging distance this way. * [Motion parallax](https://en.wikipedia.org/wiki/Parallax): the degree to which an object moves against the background as the cyclops moves its head. * [Aerial perspective](https://en.wikipedia.org/wiki/Aerial_perspective): for distant objects, this is the degree to which the object changes color as a result of atmospheric effects. * Size: the distance to an object of a known size can be determined by how small it looks. In addition, there are about a dozen techniques (perspective, occlusion, relative size, and so on) for determining the relative distance of two objects. [Answer] For anyone interested, to expound upon Will's answer, it was discovered in 2011 that birds use something called optical flow to determine distance. In computer vision, optical flow tracks the apparent movement of points as an observer moves through a scene. This picture tracks the position of similar points between two frames in a video. Notice that points farther away appear to not move as much. **Points which don't change as much between frames are assumed to be farther away.** [](https://i.stack.imgur.com/4aO1k.jpg) In the experiment, a bird was made to fly between two walls. The walls had either vertical or horizontal stripes. When moving through this hallway, the wall with the vertical stripes would move past the observer, allowing for optical flow tracking. Walls with the horizontal stripes, however, would not not appear to change as the bird flew; in the wild, this would mean that the object was far away (as we saw earlier in the description of optical flow). It was found that the birds always flew in the middle when both walls (**A**) had vertical stripes (both eyes could use optical flow tracking). When one wall had horizontal stripes (**B and C**), however, the bird flew much closer to the wall with these horizontal stripes. Since the pattern didn't appear to change as the bird moved through the hall, the bird assumed that the wall was farther away than it was. [](https://i.stack.imgur.com/E5OZH.jpg) For those interested, the name of the paper is Optic Flow Cues Guide Flight in Birds. There is also a video which shows them flying. tl;dr To answer the original question, objects which are closer appear to move more than objects which are farther away. Optical flow tracking would absolutely be a viable method for a cyclops (or any animal with monocular vision) to use to track distance. [Answer] There are many options for depth perception without binocular vision, but [chameleons](https://en.wikipedia.org/wiki/Chameleon_vision) are probably your best model for a cyclops. Unlike most animals, chameleons have a separation between their nodal point - the point wherelines connecting points in the scene and corresponding points in the image intersect - and the center of rotation, the point which the eye rotates around. This means that, as a chameleon moves its eye, images on its retina move more if they are closer, letting them determine the distance of objects. Unlike birds and snakes, which can only achieve depth perception by moving their whole head back and forth, a chameleon - or a cyclops - can achieve depth perception by moving their eye alone. [Answer] As someone who medically lacks depth perception, I can assure you there's several ways your brain learns to automatically compensate: Scale of distant objects gets matched to the 'known' scale of such objects to roughly get the distance. Over long distances, atmospheric blur is a real factor. Overlapping objects can give a good sense of relative distance. Diverging/converging lines provide perspective. Truly, how does your depth perception work when viewing something on a flat screen which was shot with one 'eye' (camera)? It really isn't as debilitating as could be thought! [Answer] Model an aspect of their sight on what bats and dolphins use for echo location. Normal human sight is completely passive. The eyes only receive light. Echolocation is active. A pulse is emitted, and time to flight from the pulse's return is measured. Have your cyclops emit a brief, bright, possibly infrared or ultraviolet, light whenever he blinks or squints. This could be worked into part of the action or plot, As the cyclops picks up the huge boulder, and prepares to hurl it, he begins blinking faster and faster as he builds up ranging data. His intended targets become more and more agitated as they know the boulder is coming their way. Also as a countermeasure, those who fight cyclops could carry a jar of hyper-luminescent fireflies who's emanations confound the cyclops' depth perception. [Answer] Adding to what people have said about accommodation: In bright light, our pupils contract. This increases the depth of field, and makes accommodation less useful for judging distance. Our technological response to this is sunglasses. They reduce the light intensity, causing the pupils to dilate, which reduces the depth of field, so your eyes have to focus carefully on what you're looking at. Your Cyclops people could have biological "sunglasses" built into their eye. In addition, you could have their retina be very light sensitive -- lots of rods. This would reduce their visual acuity, so then make their eye large to compensate (like a giant squid's eyes). Using Earth biology, this would limit your Cyclops people's color vision. [Answer] Snakes have an issue with depth perception which they solve through moving their head from side to side while looking at their prey to get an idea of how far away they are. When a snake charmer 'charms' a snake, the snake's dancing is actually them trying to work out how far away the snake charmer is so that they can attack them. The snake charmer moves from side to side as well which stops the snake working out how far away he is and attacking. The playing of the instrument does nothing but to make it look like the charmer is hypnotising the snake with music. Anyway, you cyclopes could work out distance in the same way by rocking side to side and their enemies could avoid attack in a similar way to the snake charmer. [Answer] As an adult who only has one working eye, your answers is Yes, it would completely prevent 'depth perception' as most humans know it. I can tell you that, having never known stereoscopic vision, they will have adapted to the same kinds of ways I use, whether to navigate a crowded room, drive a car or catch a Frisbee... comparative size, depth of field, many of the other methods mentioned in the excellent answers above. [Answer] There are many humans that only have the use of one eye (myself included), yet do not struggle significantly with depth perception. There are many ways to judge depth other than using multiple eyes with a baseline between them. Size, parallel lines, shadows, discolouration (scattering) are just a few of the many techniques all humans use subconsciously in conjunction with bi-angulation. People with only one eye are forced to rely on these other techniques more heavily but the situations in which you are observing withing without reference to aid you judgement and depth of field actually matters are very limited. Okay, maybe being a pilot is ill advised, but beyond that. Besides ranging devices are not uncommon and could easily be built in to things like planes (which I'm sure they already are). [Answer] I'd like to think that cyclops have no problems with depth perceptions because their eyes have multiple lens or irises; pretty sure their eye construction would be different. One has to ask why nature would favor a creature with one eye. If the single eye is just some strange mutation then there should be some amazing property of it that allows the species to survive. You could make them a species that lives in low light environments though. There are some cephalopods with large eyes that do this. If you did this then you could make vision a secondary sense and not worry about their ability to see long distance. Just have them hear their way around using echolocation and then survey what's immediately in front of them with their microscope like eyes. ]

[Question] [ A cauldron is a giant, iron pot that witches use in the creation of potions. These potions serve a variety of purposes, and it was customary for any self respecting witch to own one since the old days for containing their mixtures. However, they come with several disadvantages. Cauldrons are large and expensive, making them difficult to store as they take up much room. Their size also makes them difficult to transport from place to place. As they are mostly immobile, cauldrons are location specific, limiting their use. The iron involved in their construction also rusts over time, making them improper for doing potions long term. The expense in maintaining cauldrons along with their other drawbacks makes them impractical for modern use compared to more recent items. These days, their are newer, cheaper ways of making and storing these liquids that entrepreneurial witches can take advantage of to save on cost. I need a way to make cauldrons a staple of witchcraft despite there being other competing solutions. How can they stay relevant in the modern world? [Answer] **Surviving Cauldrons are Powerful Artifacts.** In the Golden Era of witchcraft, a big iron cauldron was an expensive thing to create. The largest and wealthiest covens might have an iron cauldron; but a smaller coven would have to negotiate using someone else's. There were never more than a thousand cauldrons in existence, and those were passed down from generation to generation, over the centuries. Over the course of hundreds of years of brewing, magical potions sink into the metal and permeate the object. The cauldron slowly acquires a magical power of its own that makes it almost indestructible, and improves the potency of potions brewed in it. Thus the original thousand cauldrons still play an important role in modern witchcraft. Every cauldron used by a modern coven is hundreds of years old. They all have proper names (usually names after the most famous past owner) and your everyday witch (or protagonist?) can make it big by stumbling upon an undiscovered cauldron buried in the earth. [Answer] ## OPTION A: Iron is to magic what lead is to nuclear reactors The idea of iron, being a magic blocking element is a pretty common trope originating from old fairy-tails that sometimes mention a material called "cold iron" as a way of killing faerie folk. Since then, iron has been the element of choice for countless authors when it comes to killing and binding various kinds of magical creatures. Many RPGs even forbid the use of iron based armor for magical classes because it blocks the flow of magic. So if you are trying to use magic, why would you want something that blocks it? The answer is simple, you need to contain it. When you are making a potion, every ingredient you add changes what sort of magic is happening in your cauldron. While your end result might be a harmless love potion, the intermediate stages might contain all sorts of magic that can cause vomiting, diarrhea, paralysis, green skin, warts, sore throat, stuttering, changes in blood viscosity and color, water allergies, changes in buoyancy, extra nipples, or even death. So, to prevent errant magics from getting out of the pot and harming the witch, he/she uses a pot made out of thick iron to block any magical energies that could seep through and effect him/her during the process. Thinner pots or pots made out of other materials simply allow the magical energies of unstable potion states to radiate through affecting the witch. If you want to go with the idea of cold-iron as opposed to any old iron, your primitive looking cauldrons work even better. One common interpretation of what "cold-iron" was is that it was iron that has never been heated to a liquid form. Prior to the late medieval period, most forges were bloomery forges. They were not hot enough to liquefy iron all the way, so "cold iron" could have been ore that was heated up to cherry red, and was then hammered, folded, and hammered some more until all the impurities were pressed out of it. This process often created complex crystalline structures in your iron like you see in pattern-welded or folded steel blades. In contrast, modern iron is pretty exclusively crucible steel which means it is fully melted, sifted for impurities, and then poured into a form; so, it by it's nature has a very simple crystalline structure. If the crystalline structure of forged iron is somehow important to the containment of magic, then typical modern metallurgy becomes useless, and all of your cauldrons will still need to be hand crafted artisan pieces. **As for competing solutions** If you go really high tech, modern meta-material research can create complex microscopic patterns in all sorts of materials. Science could replicate and even improve on the crystal patterns of cold iron by laser etching thousands of sheets of thin laminated iron filament and kiln forging them together. In doing so you could make much thinner and more portable cauldrons, but setting up high-tech meta-material labs is very expensive; so, while light weight portable potion pots could exist, the they would be much more expensive even than the hand-crafted alternative. ## OPTION B: The cauldron is the sacred icon of Cerridwen When you trace the history of the cauldron in witchcraft back to its origins you arrive at the Welsh goddess Cerridwen. Cerridwen was the goddess of the moon, prophecy, magic, death, and rebirth and the cauldron was her sacred icon. There are a few Welsh tails centered around the use of cauldrons tapping into the divine power of Cerridwen which was likely the inspiration for Shakespear's witches in Macbeth which really popularized the trope. If you go this way, it is not the pot, its contents, or the witch who is actually doing the magic, but the goddess Cerridwen bestowing divine gifts on the contents of the cauldron. By using a cauldron, you are effectively praying over an alter you've made to the goddess showing your reverence for her. The size and cost of one's cauldron shows the goddess your devotion to her; so, giant cauldrons are basically just used as a symbol of adoration to gain her favor. One could in theory pray over any old pot, and it might work if you've already proven yourself to the goddess, but most witches only use cauldrons when asking thier goddess for favors out of respect. [Answer] Law of Similarity, the great rule of magic. Like produces like. If you knock out a potion using a cheap, mass-market pot, you end up with a weak potion. A strong, sturdy cauldron lends your potion strength, and its immobility makes the potion's effects harder to be removed by outside influences, and its age makes the potion last longer [Answer] **It is not the cauldron. It is the fire.** Cauldrons are for making potions. But really what is doing a lot of the work making a potion is the fire. For ideal potions this cannot be an electrical coil or a gas jet or some other source of heat - it has to be a fire, with flame, and the things that are burning to make those flames matter almost as much as the things that go into the cauldron. Cooking a liquid over an open flame pretty much requires a pot of some sort and cauldrons work well. The problem with scaling things down to, say, a Dutch oven or smaller pot is that potions often call for entire creatures or organs to be added and they are of a fixed size. Adding just a portion of a live creature is not the same. [Answer] From a purely scientific standpoint, we now know that the purpose of the cauldron is to serve as an energy sink. The thick dense metal absorbs any residual magical energy which might be left over from recent spell casting along with the natural spillage from any nearby ley lines. Such random energies can play havoc with the magically sensitive ingredients which are required by most effective potions. A good cauldron absorbs all uninvited energies into itself, keeping everything but the fire's heat from getting inside. To function properly, a cauldron has to be large enough to neutralize whatever level of magic is likely to be present at potion making time. That is why large covens and powerful lone witches have large cauldrons while lesser witches, either alone or in triad unions can suffice with the smaller portable models. Those semi-insane techmages over on the west coast have been experimenting with combining faraday's cages and warding circles, and they have had some interesting results, but for safety and dependability, nothing beats a good old fashioned cauldron. [Answer] The power of traditions, like in any good self respecting form of cult. "This is how it was done, and this is how you will do it", it doesn't matter if you can microwave a potion in few seconds instead of stirring it in the cauldron. It can be applied to food making, liquors brewing, religions... why should witchcraft be different? [Answer] **Resonating Chamber** If magical energy had a wave nature, then if something reflected those waves and that something was the right size, then there could [standing waves](https://en.wikipedia.org/wiki/Standing_wave) of magic energy, creating a [resonance effect](https://en.wikipedia.org/wiki/Resonator). This resonance could then make the magic far more potent than it would be otherwise. So the cauldron acts like a [Helmholtz Resonator](https://en.wikipedia.org/wiki/Helmholtz_resonance). The boundary between the air and the potion could also be reflective, adding to the resonance. [Answer] Drastically different take here that kind of challenges your premise a bit at first, but bear with me. ### The cauldron itself is only an accessory to the spellcasting, acting as a catalyst. Perhaps it makes it easier to concentrate the magic required for producing the potions, or maybe it's a meditation aid that simplifies focusing your mind in the way required to actually prepare the spell used to actually prepare the potion. The exact details don't really matter and can just be fluff for the story. The important thing is just that using a cauldron makes it easier to do the actual magic. Once you're there, it's simple to extrapolate that the mark of a truly skilled or powerful witch is that *they don't actually need a big iron cauldron*. Such individuals are rare though, so your everyday witch who needs to do any kind of serious potion making (that is, non-trivial potions, or production of very large batches of simple ones) just uses one all the time because they'll need it anyway for the big stuff, so there's no point in not using it for the little things. You can reinforce this logic though by leaning on psychology (or, as it's alternately known in this context to the witches of Terry Pratchett's Discworld 'headology' or 'Boffo', I very much recommend reading some of his books that follow the witches because they do a great job of explaining this through demonstration). In effect, everybody *expects* witches to have a big iron cauldron, so the witches oblige and play the part because: 1. It's good advertising. You've got all the hallmarks of being a witch, ergo everybody treats you like one. This makes setting up in a new area or dealing with new people much simpler. 2. It has somewhat of a placebo effect due to confirmation bias. IOW, because everybody *knows* witches know what they're doing when it comes to healing potions, obviously something a witch gives you and tells you is a healing potion *has* to work, because they know what they're talking about. This, in turn, can feed further back into both itself and the advertising aspect. Putting all this together, you end up with a situation where every witch has a cauldron because no self-respecting witch wouldn't have a cauldron, even if they don't actually *need* a cauldron. [Answer] **Volume is important** Potions involve a great deal of reduction, siphoning off elements you don't want or need, concentrating elements you want lots of. Ultimately, you need a great volume of liquid to work with, and it's far more convenient to have it all in one place. An ultra-modern potion-maker might use vats and keep their ingredients in factory-scale bulk, use centrifuges to isolate the elements they need. But that needs infrastructure that a hedge-witch doesn't have. So a big metal bowl isn't going to go out of fashion any time soon. [Answer] **The age and condition of the cauldron is already incorporated into the spell and potion making.** Both the rust, and accumulated grime and magical residue from repeated uses are ingredients in the magic. Spells and potions take, and even demand certain condition cauldrons, into consideration for gaurenteed results. While modern day witches might be able to quantify the amount of rust/iron to add to a spell/potion to modernise the process, the magical residue and age pattenas are something that hasnt been successfully replicated in the spotless stainless steel modern witches kitchens...yet. reworking the 1000 year old recipes for modern cauldrons is going to take *some* time. Variations of POTION RECIPES * one large 10 year old partially rusted cauldron * 1 small - medium well aged cauldron in good condition. (Only slight age discoloration allowed or else potion potency cannot be guaranteed). * 1 pot with no previous history of making class 5 potions or above * 1 medium partially maintained pot with several years of adept potion making imbued in the rim. Bottom of pot must be well scoured. It's also why any well-versed witch has several cauldrons on hand. Also why while sharing pots isn't exactly prohibited, it's not considered best practise. You definitely don't want to inherit the magical residue from the neighbour who blew themselves up last week! [Answer] Iron oxide is toxic, but like all toxins it's dose dependent. Therefore one could build a strong tolerance to some toxins over time by consuming smaller amounts of that same substances. Maybe your witches like to drink the blood of young virgins so they remain younger or don't age....whatever, make up something...maybe they just like to eat children's liver and bone marrow. Blood, liver and bone marrow are highly toxic for a normal person because of the high quantities of iron, but someone who is used to the toxicity of iron can tolerate it. That's why some people get sick from eating blood while others can tollerate it, the same reason a chickens liver doesn't kill you but no one can eat a bear's liver and survive. By natural selection witches using rusty dirty and old cauldrons build up a tolerance to iron and are able to eat more children/drink more blood and live longer. While the witches using modern tech don't build that same tolerance to iron. Also, no ....eating veggies high in iron doesn't build iron tollerance because vegetal iron is already filtered out by the body when in excess. [Answer] > > Cauldrons are large and expensive, making them difficult to store as they take up much room. Their size also makes them difficult to transport from place to place. As they are mostly immobile, cauldrons are location specific, limiting their use. > > > Sometimes you just need to have a log of liquid in a place from where you won't be leaving for a while. That's why even though beer cans have been a thing for quite long, kegs are still a thing. > > The iron involved in their construction also rusts over time, making them improper for doing potions long term. > > > As other have said, the iron is the secret ingredient in the stronger potions. > > The expense in maintaining cauldrons along with their other drawbacks makes them impractical for modern use compared to more recent items. These days, their are newer, cheaper ways of making and storing these liquids that entrepreneurial witches can take advantage of to save on cost. > > > That does not happen with potions only. It's with everything. There are some american wines that sell for under three dollars a bottle. But if you've ever tasted real wine (even the cheap ones that go for 40 USD a bottle), you'll never want to come within a foot of distance from the bootleg stuff. That's because plastic will never age wine like a cask will, and that's why most of the money in the industry goes to wineries and not prison gangs. > > I need a way to make cauldrons a staple of witchcraft despite there being other competing solutions. How can they stay relevant in the modern world? > > > It's all about a market niche. Yeah Alley Sally sells flu cures at \$1 a plastic bottle, but all that bisphenol A will destroy your gonads in a couple years. I wish to stay healthy for the foreseaable future, so I'll still be paying $60 on an iron flask at the local apothecary. [Answer] For the record, you can buy small cauldrons, about 4 inches in diameter. You might have the traditional large cauldrons be used in a single location (the witch's kitchen which would parallel their traditional use on the hearth) or be reserved for the use of a coven. Individual witches could use the smaller cauldrons. Also, many potions (just like cooking) give better results when the ingredients are simmered together for a while, rather than throwing them all in a bowl and putting them in the microwave. Also, think about cast iron pots, which are seasoned over time and that lends a flavor to what is cooked in it. Sometimes it might be about convenience and then a microwave mix might do, but there are advantages to sticking with a cauldron. Also, cauldrons can be used for purposed other than mixing a potion -- you can burn something in a cauldron without catching your house on fire. Chanting over burning ingredients (or when stirring - think Macbeth) is another venue where cauldrons work better than microwaves or stovetops. [Answer] Size and metallurgy could play a role in this process. **Size** Google up images of camp fire pots, most of these are for cooking over a camp fire usually suspended over the fire with sticks or metal rods. They aren't much bigger then a normal stove top pot. So smaller size means more portable, easy to bring out into the woods or over to a coven meeting, hell you can have 3 or 4 potions on an electric stove going at the same time. **Technology** Others here allude to things like recipes and things like "cold iron" as relates to magic. But we can go the other route, new cauldrons and potions might do better in different containers. Stainless steel (no rust), aluminum (weight), etc. Most of the time "fancy" tools engraved on the outside, but this is witch craft; perhaps new cauldrons have engravings on the inside. Maybe those engravings are lined with special materials for purity or magic. "Use a silver inlaid cauldron to maximize the purity of this process." [Answer] **It's a status symbol** Only the wealthy or well-established witches have cauldrons. Sure, you could make it in a fancy new scientific material or a small container... but you're not seen as a committed witch. The flimsy stuff is for the hobbyists; the cauldron is for the real witches. **Why?** Well, *Cerridwen used the cauldron*, so it's become quite a bit of a symbol to have something that hearkens back to the source. Due to this, the elite witchcraft supply builders put their *best materials into their cauldron models*, because they know that the elite (or wannabe elite) witches will buy the cauldrons and expect it to be the best. (This answer is a riff off of [two](https://worldbuilding.stackexchange.com/a/178324/51552) [other](https://worldbuilding.stackexchange.com/a/178315/51552) answers.) [Answer] Thermal mass. Cast iron has a lot of thermal mass, which is great for evening out fluctuations in the heat source and maintaing a steady temperature of the contents. The traditional fire is not a very stable heat source, so cast iron cauldrons helped to keep the heat on the potion constant. Better technology can give more stable heat sources, which wouldn't require a heavy cast-iron vessel to make your potions in, but you might not own one. You might have improvised your heating setup with cheap electric hotplates that turn on and off a couple of times per minute, and thus need the thermal mass of a cast-iron cauldron if you want to produce anything decent. As for why you'd want a big cauldron, simple volume. If you sell 50 litres of burn-treatment a month, you'd want a big cauldron to brew a big batch in, so you can minimise the time you spend on brewing popular potions. Just a matter of how much you sell and how long it keeps that determines how big a cauldron you use to brew it. The traditional witch probably had a few sizes of cast-iron cauldron, but the big one just stuck in everyone's mind because it was so unusual to see one that big. ]

[Question] [ My Kingdom X is a great and prosperous nation, having a decent amount of natural resources. The kingdom's founding dynasty has stood the test of time for 1000s of years, until Kingdom Y launches a war against them. The world is 25% the size of Earth for creative reasons, with Earth gravity. Kingdom X is located on a landmass 1/4th the size of Asia (scaled) and the only other landmass is Europe, on the other side of the world and unknown. The world is Earth like and inhabited by humans. A form of magic will be involved, but I'll either put in later enough (aka when Kingdom Y attacks) or make it relatively balanced like guns are nowadays. Natural phenomena are the same, and so are humans biologically. Differences of education/deep-rooted thoughts may be changed, but I don't know how much that change anything. How do I make this long dynasty (around 1000 - 2000 years) realistic? The only dynasty I can see is the Zhou dynasty (we'll ignore the differences in dynasties that conquer/unify vs those that rule for now), and even that only lasted around 800 years. The kingdom has a group of people loyal to the king in the beginning, and it is relatively peaceful (aka no wars of aggression during this time period), but change is happening around them so I need for them to be able to resist outside and inside pressures/changes. The kingdom is well-protected by a mountainous range, but there is a massive gap where opposing armies could get through. The original dynasty built a wall there, but we all know what happens when walls/the military fall into disarray. The kingdom also is the only exporter of [insert natural resource here], which gives it great wealth but also make it an attractive target. [Answer] It's nice to see someone acknowledging that maintaining a dynasty for more than a few centuries is a very, very difficult proposition: too many fantasy works casually write 'and the House of X has ruled Kingdom Y for 10,000 years' without considering how unparalleled this is in human history. One thing to note that is if you want your specific dynasty (i.e. the actual same family) to continue in power for that long, you will need the right sort of social set-up (e.g. polygamy as practised in the Ottoman and Chinese empires, or an arrangement that allows the dynastic title to be transmitted to women or adopted children), as Western-style monogamous patrilineal dynasties almost invariably go extinct in the male line after a few hundred years; one family can't keep consistently churning out sons for generation after generation, unless you use some kind of fertility-magic as a fix for this. Otherwise, you will need a political system which emphasises stability and perhaps has a special spiritual role for the royal family. The Yamato dynasty in Japan (the current longest-reigning dynasty in the world, having endured 1400 years and counting) have survived largely because for much of this time they have been symbolic leaders, regarded as quasi-divine beings but not entrusted with day-to-day power, thus preventing them from being brought down by the failings of the government of the day. I would emphasise geography as the reason for not being conquered in external attacks; you mention mountains, and ruling over a country with large mountainous areas which they could use as a defence against invaders worked quite well for the Bagrationi dynasty, who held out in Georgia for nearly 1000 years. Even if invaders breach your wall, perhaps if the dynasty has strong enough support from the people it can resist from impregnable mountain bases until the attackers are eventually forced to cut their losses and withdraw. Ultimately, however, there is no one 'right' answer to this question; if there was then more families would have managed it, since almost every dynast in history has wanted their family's rule to last for thousands of years! [Answer] # First, follow a modified Saudi Arabian model. In a nutshell, royals are polygamous and have many children, but successors are chosen and announced as successors by the existing ruler not purely based upon birth order and descent, but instead, based upon competence from among the people who are eligible (i.e. adult royals). The existing ruler could change the successor at any time. Thus, someone in a cadet line could be named as successor by the existing ruler. Also, cousin marriage would be prohibited for royals, to prevent inbreeding problems that have plagued, for example, the European aristocratic dynasties, as well as the sibling marriages that plagued the Egyptian dynasties. This would solve the incompetent Crown Prince problem, the inbreeding problem, and the complacency issue of hereditary princes and princes having no incentive to perform competently or show loyalty to the current monarch. An absence of incompetence and inbreeding would also help support for the institution of the monarchy generally (see, e.g. how the Papacy survived for about 2000 years without facing those issues). The one problem with the Saudi Arabian model is that it generates too many royals since all descendants of the original founding monarch are eligible. But, narrowing the pool of eligible descendants to descendants of the current monarch's grandparents, for example, would fix that long run problem. Birth order type priorities among eligible successors would apply only in rare cases where a successor did not have an opportunity to name a successor. Patriarchal, matrilineal and gender neutral variations on this theme could all work. # Second, have a stable, "rent" based economy. The transition from monarchy to constitutional monarchies and Republics typically arises when the monarchy can no longer fund the activities of government with revenues limited to the income from property-like assets that the monarchy owns personally. Almost all of the remaining absolute monarchies are sustained by oil wealth. The European monarchies mostly transitioned to Republics or constitutional monarchies when merchants and manufacturers generated wealth that wasn't captured by rents on royally owned land (managed through a feudal hierarchy), and so the monarchs had to go to the economically powerful people and trade them power for tax revenues. This same script played out, for example, in England, France, Spain and Afghanistan. Other places (like Northern Italy) lost their monarchies when they were conquered by newly formed Republics, or just out and out rebelled in taxation without representation driven revolutions (e.g. the American Revolution). So, a long dynasty needs a source of revenue that is a dominant source of wealthy in the economy for thousands of years, that is "rent-like." [Answer] There is no inherent reason why a dynasty needs to change after some time. Polygyny and Concubinage can help ensuring the survival of the family, and in history it was somewhat common to adopt the husband of a daughter into the family when the male line was under threat. Assuming a dynasty doesn't die out, it can usually be replaced in two ways: Either the polity and the dynasty are very closely knit together (like in China, Persia or the Islamic world), in which case the dynasty's rule ends when it falls behind its neighbours militarily or economically - which can be avoided by having the country be in a geographically and diplomatically favourable position. The *Course of Empire* is always going to be a problem, but the cycle can be slow, the decline can be dragged out, decadence can be subdued by religion, and even within a dynastic rule there can be minor renewals - or major ones if the ruling dynasty is separate from the government. There can be whole Civil Wars between Daimyos, Lords, chancellors or magnates that don't affect the Royal house at all. In any case, 2000 years are not unrealistic I think. Or the polity and the dynasty are separate (like in Europe), in which case the dynasty's rule ends because the local estates (or whoever holds power) are not content with their rule. This can be avoided by making the dynasty's power base itself very strong (this is essentially like the first case, just on another level). It's also possible that the estates have high autonomy and simply don't care about who rules as long as they have low obligations towards the crown. In a fantasy world, there can of course always be the aspect of a bloodline being tied to rulership - like Elendil's heirs to the thrones of Gondor and Arnor. [Answer] **Part One of Three: What is a Dynasty?** The word dynasty is often used loosely. > > a line of hereditary rulers of a country. > "the Tang dynasty" > synonyms: bloodline, line, ancestral line, lineage, house, family, ancestry, descent, succession, genealogy, family tree; More > a succession of people from the same family who play a prominent role in business, politics, or another field. > "the Ford dynasty" > synonyms: bloodline, line, ancestral line, lineage, house, family, ancestry, descent, succession, genealogy, family tree; More > > > Even that definition seems a bit loose to me. I tend to use the word dynasty to mean rulers descended in the male line from father to son to grandson to great grandson, etc. That is called agnatic descent. That doesn't mean that there would be no legal way for the crown to pass from one dynasty to another. Who gets to inherit depends on the succession laws. In medieval and modern times there were two main succession rules in Europe. One was agnatic primogeniture. That means the succession passed from father to oldest son to oldest grandson to oldest great grandson, etc., or to the closest agnatic (male lineage) man related to the old ruler if the old ruler had no sons. Sometimes that meant the throne would be inherited by a distant cousin of the previous ruler, with a common agnatic ancestor centuries earlier. That law ensured that the throne would remain within the agnatic dynasty of the original family as long as the dynasty lasted or wasn't overthrown. The second main rule was male preference primogeniture, in which the crown would preferably pass to the oldest son of the oldest son of the oldest son forever. If a ruler's oldest son died before his father but left sons the oldest of those grandsons would inherit. If a ruler or someone in line for the throne died without sons but with daughters the oldest daughter would inherit the right to the throne. The daughter of the previous ruler was preferred to the brother, cousin, or other relative of the previous ruler. That was the main succession rule in most of medieval and modern Europe. The founder of a dynasty might prefer agnatic primogeniture because that would keep the throne within his male lineage family down through the ages. Each successive king might prefer male preference primogeniture to keep the crown within his own descendants instead of it possibly passing to descendants of his brothers or cousins. Because male preference primogeniture was probably the most common succession rule in medieval Europe, the kingdoms, principalities, and fiefs which practiced it often passed legally and peacefully from one dynasty to another when the heiress married a member of another dynasty. In the last 40 years or so, in the lifetimes of some people who read this, most remaining European monarchies have adopted a new succession law, absolute primogeniture, which means that the oldest child of the monarch will inherit the throne, whether male or female. Since there are about equal numbers of males and females born, about 50 percent of the time the crown will be inherited by a woman, and if she marries and has children the throne will pass legally to a new dynasty. There are many, many other succession rules used in Europe and other regions. Some of them require that the crown will remain within the same agnatic dynasty while others permit the throne to pass from one agnatic dynasty to another. In some monarchies the crown can only pass from one man to another man through a woman, meaning the new monarch will usually be the sister's son of the previous one and thus a member of a new agnatic dynasty, though in those countries the family and dynasty is usually defined as passing through the female line. And some dynasties pass the throne from one woman ruler to another, usually her daughter, and these usually pass from one agnatic dynasty to another whenever a new woman succeeds. So the founder of the dynasty should decide what he means by his dynasty when he tries to come up with a plan for it to last for thousands of years. One obvious way for a dynasty to last for thousands of years is for the dynasty to actually be as divine as many dynasties claimed to be. If the dynasty actually is descended from gods, angels, elves, etc., they might be different from those who are fully human. Maybe they live ten times as long as normal humans, maybe they are far more intelligent, maybe they look super humanly beautiful, maybe they are bigger or smaller than ordinary humans, maybe they have magical powers, maybe they glow in the dark, etc., etc., etc. Some dynasties believed in marrying sisters, half sister, aunts, nieces etc. to keep their supposed divinity concentrated within the family. But that was dangerous because marriages with first cousins or closer relatives can concentrate harmful recessive genes within future descendants. But if a family actually is divine and doesn't have any harmful genes, brothers can marry sisters for generation after generation and their descendants can be obviously superior to normal humans, while those members of the dynasty who intermarry with normal humans may produce more average and ordinary children. If the members of your dynasty aren't really divine, semi divine, supernatural, etc., they will often seem like normal, ordinary people to other people. Thus those other people might believe that they are as good as the monarch and might plot to usurp the throne from the rightful heir or abolish the monarchy. As far as I know, no real dynasty has been divine or supernatural, which explains the problems which many real dynasties have had with keeping the throne for centuries without dying out, being usurped, or being overthrown in favor of a republic. So unless your dynasty is very supernatural or divine, you should try to find out which dynasties lasted the longest in real history and why they lasted that long. **Part Two of Three: A List of the Longest Lasting Dynasties** Studying the histories of long-lasting dynasties may show why and how they lasted so long. For fun, here is a list of the allegedly longest lasting dynasties in history. Note that some historians exaggerated the antiquity of their country's history, especially in medieval or ancient times when the history of those countries was much shorter than now. 1) The Dulo Dynasty supposed ruled the largely nomadic Bulgarians for 2,890 years, from 2137 BC to AD 753. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) According to Wikipedia the historical rule of the Dulo clan was from 632-668 in Old Great Bulgaria and from 681-753 in the first Bulgarian Empire. <https://en.wikipedia.org/wiki/Dulo_clan> 2 2) The Yamato Dynasty supposedly ruled Japan from 660 BC to the present, or about 2677 years. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) But the early Japanese rulers are generally considered legendary and mythical, and the first fully historical ruler of the dynasty is often said to be Kinmei, who ruled from AD 539 to 571 - his reign was thus from about 1479 to about 1447 years ago if the dates are correct. Kinmei was a son of Keitai who reigned about AD 507-531 and was allegedly a distant cousin in the male line of the previous ruler Buretsu (reigned about 498-506). <https://en.wikipedia.org/wiki/List_of_Emperors_of_Japan>[3](https://en.wikipedia.org/wiki/List_of_Emperors_of_Japan) Cynical historians believe Keitai may have been a usurper unrelated to Buretsu. So the Yamato dynasty either began in AD 507 1511 years ago when Keitai usurped the throne, or else was a continuation of a dynasty going back a few centuries further. 3) The Hong Bang or Lac Dynasty of Vietnam supposedly ruled for 2,639 years from 2897 BC to 258 BC. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) According to Wikipedia there is no proof that the 18 lines of the Hong Bang Dynasty really existed. I note the 18 would have ruled for an average of about 146.6111 years. <https://en.wikipedia.org/wiki/List_of_monarchs_of_Vietnam#H%E1%BB%93ng_B%C3%A0ng_Dynasty> [4](https://en.wikipedia.org/wiki/List_of_monarchs_of_Vietnam#H%E1%BB%93ng_B%C3%A0ng_Dynasty) 4) The Gojosan Dynasty supposedly ruled Korea for 2,225 years from 2333 BC to 108 BC. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) As may be guessed from the dates, the Gojosan realm is considered to be a lot younger than that. Chinese records mention Gojosan from the 7th century BC. Furthermore, legends claim that Gija, refugee from China, founded a new dynasty in Gojosan about 1122 BC. And a historical Chinese immigrant, Wi Man, founded new dynasty in Gojosan in 194 BC. Thus Gojosan seems to have been a state, not a dynasty, and to have had three separate dynasties that allegedly reigned for about 1,211 years, 928 years, and 86 years, and only the third period is fully confirmed. <https://en.wikipedia.org/wiki/List_of_monarchs_of_Korea#Family_tree>[5](https://en.wikipedia.org/wiki/List_of_monarchs_of_Korea#Family_tree) <https://en.wikipedia.org/wiki/Gojoseon>[6](https://en.wikipedia.org/wiki/Gojoseon) 5) The Champa Dynasty supposedly ruled Vietnam for 1,640 years from 192 BC to AD 1832. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html> [1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) But Champa was a state ruled by non Vietnamese in southern Vietnam, and according to Wikipedia it had 17 dynasties from AD 192 to AD 1832, which ruled for an average of 96.47 years. <https://en.wikipedia.org/wiki/List_of_monarchs_of_Vietnam#H%E1%BB%93ng_B%C3%A0ng_Dynasty>[4](https://en.wikipedia.org/wiki/List_of_monarchs_of_Vietnam#H%E1%BB%93ng_B%C3%A0ng_Dynasty) 6) The Belle Dynasty or Balliol Dynasty of Flanders in Belgium has supposedly been in existence and reigning for 1,049 years from 960 to the present (thus "the present" should be 2009). <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) I don't know what this is supposed to be. A Balliol family were important Scottish nobles for centuries, and two members became kings of Scotland, but I know of no relationship of them with any dynasty reigning today that is close enough that someone would call them the same dynasty. 7) The Bagratuni Dynasty supposedly ruled Georgia for 997 years from AD 813 to 1810. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) And that is pretty much accurate, for once in this list. Adarnase, a Bagratuni noble from Armenia, fled to Georgia and gained the fief of Tao-Klarjeti. His son Ashot I the Great became Presiding Prince of Georgia in 813. His descendant Adarnase IV became the first King of Georgia in 888, so the Bagratunis were actually only kings for a "mere" 922 years. I also have to admit that Georgia's mightiest medieval ruler was Queen of Kings Tamar who reigned from 1184 to 1213. Thus her descendants are actually descended from her second husband King Consort David Soslan in the male line. He was a prince from Alania who later chroniclers claimed was actually also a Bagratuni, the 4th Cousin of Tamar's father. Thus it is unknown whether the Georgian Bagratuni were one dynasty or two dynasties. 8) The Silla Dynasty ruled the kingdom of Silla in Korea for 992 years, from 57 BC to AD 935. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html> [1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) This is another case where this list is not so Silla. However, members of three different dynasties, the Pak, Seok, and Kim families, ruled the kingdom of Silla, so it wasn't ruled by one dynasty straight for 992 years. 9) Tonga was supposedly under the Tu'i Dynasty from AD 900 to 1865, or 965 years. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) As near as I can tell rulers with the title of Tu'i Tonga ruled Tonga from about 900 to about 1500 and reigned as priest kings from then until 1865 while other leaders ruled. And they seem to have been a single dynasty as far as I can tell. <https://en.wikipedia.org/wiki/Tu%CA%BBi_Tonga>[7](https://en.wikipedia.org/wiki/Tu%CA%BBi_Tonga) 10) The Zhou Dynasty is said to have ruled China for 790 years from 1046 BC to 256 BC. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) And this is pretty accurate. However, certain historical dates in Chinese history begin in 841 BC. Earlier dates are uncertain. Many different dates have been suggested for the overthrow of the Shang Dynasty by the Zhou Dynasty. I may have more to write later about long lasting dynasties which may serve as model for fictional long lasting dynasties. Added Sept 11-2018. **Part Three of Three: A Fairly Accurate List of 20 Long Lasting Dynasties** Here is a more plausible list of long lasting dynasties. Figuring out how they managed to keep their thrones for so long may influence someone wanting to write about fictional long lasting dynasties. Note that there is considerable uncertainty about the length of many of those dynasties. I expect that there are a few other dynasties that should be on this list, for example Irish dynasties whose legendary history goes back for thousands of years, and which ruled for about a thousand years in more or less accurate history. For a brief discussion of Irish dynasties see post # 18 at: <https://historum.com/threads/what-were-the-longest-lasting-dynasties-in-europe.139428/page-2>[8](https://historum.com/threads/what-were-the-longest-lasting-dynasties-in-europe.139428/page-2) And: <https://en.wikipedia.org/wiki/Gaelic_nobility_of_Ireland>[9](https://en.wikipedia.org/wiki/Gaelic_nobility_of_Ireland) Note that many dynasties still exist as families decades, centuries, or millennia after losing their kingdoms. For example, the "House of Aberffraw" ruled the Kingdom of Gwynedd and claimed to be kings of the Britons from about 825 to the conquest of Gwynedd by Edward I in 1282/83. Merfyn Frych became king of Gwynedd through descent through his mother from the "House of Cunedda" that ruled Gwynedd from the time of Cunedda about 400 AD. Merfyn's father Gwriad was descended from Coel the Old, who lived about 400 AD. The ancestry of both Cunedda and Coel is traced back to Beli Mawr who would have lived about 100 BC. A few Welsh families trace their descent back to Cunedda or Coel or other 5th century rulers and to Beli Mawr. Evan Vaughn Anwyll of Tywyn (b. 1943) is considered the heir of the "House of Aberffraw" and the "House of Cunedda". Similarly there is a Kung clan in China tracing their ancestry back over 2,500 years to Confucius, whose ancestry is traced in turn to the Shang Dynasty that was overthrown over 3,000 years ago. Dynasties listed in ascending order of maximum real or alleged duration: 20) 650 years and counting. Sultanate of Brunei, 1368 to present. 19) 677 years. Shirvanshahs of Shirvan. The longest lasting Islamic dynasty ruled Shirvan as a sometimes vassal and sometimes independent realm for 677 years from 861 to 1538. Note they sometimes claimed to be descended from the Sassanid dynasty that ruled Iran from 224 to 651. 18) 850 or 805 years. The Capetian Dynasty. Various branches of the Capetian Dynasty ruled France for 805 years straight from 987 to 1792. Also for 10 years from 888 to 898, 1 year from 922 to 923, and 34 years from 1814-1815, and 1815-1848, for a total of 850 years during a span of 960 years. They are sometimes divided into separate dynasties like direct Capetians, Valois, Bourbon, and Orleans. 17) 866 or 790 Years. The Zhou Dynasty. Many different dates for the Zhou Dynasty overthrow of the Shang Dynasty have been proposed. Liu Xin about 1 AD calculated that the Shang Dynasty ruled 644 years from 1766 BC to 1122 BC, the "Bamboo Annals" indicate the Shang ruled for 520 years from 1566 to 1046 BC, and the Xia-Shang-Zhou Chronology Project calculated that the Shang Dynasty ruled for about 554 years from c. 1600 to 1046 BC, among other calculations. The Zhou Dynasty traditionally ended in 256 BC when King Nan of Zhou was killed and his state conquered by Qin. The last Zhou holdouts were defeated 7 years later in 249 BC. The Sui Dynasty that ruled from AD 581 to 618 and reunited China claimed to be descended from the Zhou Dynasty. 16) 997 years or 922 years, or 802 years or 400 years or 325 years or 205 years. The Bagrationi Dynasty of Georgia was founded by a Bagratuni noble from Armenia. His son Ashot I the Great became Presiding Prince of Georgia in 813, Adarnase IV became King of Iberia in 888, and Bagrat III united all Georgia in 1008. King Solomon II of Imereti was deposed by Russia in 1810. Thus the Bagrationi Dynasty ruled Georgia for 802 years since 1008, or 922 years since 888, or 997 years since 813. But Queen of Kings Tamar (reigned 1184-1213) was followed by her son King of Kings George IV Lasha (1213-1223) whose father was Tamar's second husband David Soslan from the royal family of Alania. It has been claimed that David Soslan was himself a Bagrationi, being the 4th cousin of Tamar's father George III. If so, the Bagrationi Dynasty ruled Georgia for 802, or 922, or 977 years. If David Soslan was not a Bagrationi the Bagrationi Dynasty only ruled George for 205, or 325, or 400 years until 1213, and a new dynasty descended from David Soslan ruled for 597 years from 1213 to 1810. There was also a branch of the Bagrationi who were descended in the male line from the Seljuk Sultans of Rum. See post number 20 at: <https://historum.com/threads/what-were-the-longest-lasting-dynasties-in-europe.139428/page-2>[8](https://historum.com/threads/what-were-the-longest-lasting-dynasties-in-europe.139428/page-2) 15) 1,029 or 764 or 508 years. The Abbasid Caliphs at Baghdad reigned, and sometimes ruled, their usually shrinking realm for 508 years from 750 to 1258. A branch of the Quraysh tribe. A line of nominal Abbasid Caliphs with nominal authority reigned at Cairo during the time of the Mamluk Sultans of Egypt for 256 years from 1261 to 1517. The Nawabs of Bahawalpur ruled as vassals of various rulers for 265 years from 1690 to 1955, and their Abbasi tribe claimed descent from the Abbasid Caliphs. Thus various branches of the Abbasids may have ruled various places for a total of 1,029 years. [added Mar. 06 2019. Years ago surfing the internet I landed on a page describing a family vacation which seemed pretty ordinary and boring except that the two young sons had the title of "Emir". Reading further, I found that the family claims be be descended from the Abbasids.] 14) 1,050 or 957 or 817 or 724 years. Various Sharifs, descendants of the prophet Muhammed, were Emirs of Mecca, usually under various overlords, from about 964, when Jaafar al-Musawi was appointed. His descendants were appointed to rule Mecca until about 1201 when Qatada ibn Idris, another Sharif, became the founder of a dynasty that ruled Mecca for 724 years until 1925 and continue to rule in Jordan for a total of 817 years. I don't know if Qatada ibn Idris was descended from Jaafar al-Musawi or was a very distant cousin. Sharif Hussein ibn Ali proclaimed himself King of the Hejaz in 1916, but the kingdom was conquered by Nejid in 1925. His descendants were kings of Iraq for 35 years from 1923 to 1958 and emirs and kings of Jordan for 97 years from 1921 to the present. 13) 1,065 years. The Rassid dynasty of Imans ruled parts of Yemen for about 1,065 years from 897 to 1962. Since they claimed descent from Muhammed they are part of the Qurash. They were divided into various clans that competed and fought for the imanship, though. 12) 1,118 years or up to 950 years. The Tu'i Tonga Dynasty of Tonga. The first *Tu'i Tonga* monarch could have ruled as early as 900. Tonga was very powerful from about 1200 to 1500. From around 1470 the *Tu'i Tonga* Kau'ulufonua ceded political power to the first *Tu'i Ha'atakalaua*, his brother. The last *Tu'i Ha'atakalaua* ruled about 1800 or so. The line of *Tu'i Tonga* continued until the death of Lafilitonga in 1865. The 6th *Tu'i Ha'atakalaua*, Mu'ongatonga, created the position of *Tu'i Kanokupolu* for one of his sons, Ngata. The 19th *Tu'i Kanokupolu* (from 1845) eventually conquered and united all the warring states of Tonga in 1852 and was crowned King George Tupou I of Tonga in 1875, the ancestor of the kings and queens to the present. As far as I can tell the various leaders are all one dynasty, the line of *Tu'i Tonga* for possibly as long as 965 years, the *Tu'i Ha'atakalaua*, the *Tu'i Kanokupolu*, and the Kings from 1875 to the present all seem to be branches of one dynasty which may have ruled for as long as 1,118 years. 11) 1,130, or 1,009 or 944 years. Various branches of the Capetian Dynasty ruled France for 805 years straight from 987 to 1792. Also for 10 years from 888 to 898, 1 year from 922 to 923, and 34 years from 1814-1815, and 1815-1848, for a total of 850 years during a span of 960 years. Other branches of the Capetians ruled other Kingdoms like Spain from 1700-1808, 1813-1868, 1874-1931, and since 1975, Portugal from 1139-1910, and the grand duchy of Luxembourg from 1964 to the present. So various branches of the Capetians have ruled various monarchies for 944 straight years from 987 to 1931, and for a total of 1,009 years spread over a span of 1,130 years. They are sometimes divided into separate dynasties like direct Capetians, Valois, Bourbon, Orleans, Avis, & Braganza. 10) 1,411 or 1,211 years. The Shang Dynasty. Many different dates for the Zhou Dynasty overthrow of the Shang Dynasty have been proposed. Liu Xin about 1 AD calculated that the Shang Dynasty ruled 644 years from 1766 BC to 1122 BC, the "Bamboo Annals" indicate the Shang ruled for 520 years from 1566 to 1046 BC, and the Xia-Shang-Zhou Chronology Project calculated that the Shang Dynasty ruled for about 554 years from c. 1600 to 1046 BC, among other calculations. Shang descendants ruled the vassal state of Song until Dai Tcheng usurped the throne in 355 BC. Dai Tcheng was a "distant relative" of the ruler but I don't know if he was descended from the Shang Dynasty. The State of Song was conquered by the state of Qi in 286 BC. 9) 1,417 or 1,213 years. The Dynasty of Mewar or Udaipur. The state of Mewar was said to have been founded about 530 or 734, and was ruled by the Guhilot clan and then the Sisodia branch of the Guhilot clan until 1947. 8) 1,422 or 1,302 years. The Chera Dynasty of southern India. The Chera dynasty supposedly ruled various parts of south India for 1,422 or 1,302 years from some time during the 3rd century BC to AD 1102 or 1122. <https://en.wikipedia.org/wiki/Chera_dynasty>[10](https://en.wikipedia.org/wiki/Chera_dynasty) One source claims the Chera Dynasty ruled for 1,500 years from 300 BC to 1200 AD. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html> [1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) I am not very familiar with the dynasties of south India and I am not certain about how much the Cheras were a single dynasty. 7) 1,538 years. The Quraysh tribe of Mecca could be considered to be a dynasty that has ruled for at least about 1,538 years. Among long lasting dynasties the Quraysh tribe of Mecca could be considered one of the longest ruling. The members are supposedly descended from Fihr ibn Malik, whose 6th generation descendant Qusayy united the Quraysh and took control of Mecca and the Kaaba. From that time to the present at least one member or alleged member of the Quraysh, and often many at the same time, has been a prominent leader in Meccan, Arabian, and/or Islamic society. The prophet Muhammed is believed to have lived from about 570 to 632. He was the son of Abullah (born c. 530-550), son of Abdul-Mattalib (b. c.490-530), son of Hashim (founder of the Hashimite branch) (b.c.450-510), son of Abd Manaf (b.c.410-490), son of Quasyy (b. 370-470) - Wikipedia says Quasyy lived from about 400 to about 480. So various members have the Quraysh have been more or less hereditary leaders of various societies for at least about 1,538 years since about 480. Some people may consider the Quraysh more like a bunch of related and shorter lived dynasties than like one single dynasty ruling for all those 1,538 years. 6) 1,579 or 1479 years. The Chola Dynasty is said to have ruled in parts of south India for 1,479 to 1,579 years between some time in the 3rd century BC to AD 1279. <https://en.wikipedia.org/wiki/Chola_dynasty> [11](https://en.wikipedia.org/wiki/Chola_dynasty) It has been claimed the Cholas ruled for 1,557 years from 278 BC to AD 1279. <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html> [1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) I am not very familiar with the dynasties of south India and I am not certain about how much the Cholas were a single dynasty. 5) 1,876 years. The Celestial Masters of the Zhengyi Dao branch of Daoism or Taoism claim to be descended from Zhang Daoling who founded the Daoist religion about AD 142, 1,876 years ago. That is not a political dynasty but it is a dynasty of religious leaders alleged to be 1,876 years old. <https://en.wikipedia.org/wiki/List_of_Celestial_Masters> [12](https://en.wikipedia.org/wiki/List_of_Celestial_Masters) 4) 1,938 or 1,914 years. The Ningthouja Dynasty of Manipur in south India. The Ningthouja Dynasty is said to have ruled for 1,914 years from AD 33 to 1947 when Manipur became part of India, or according to some for 1,938 years until 1971 when India abolished the privileges of the royal families. <https://en.wikipedia.org/wiki/Ningthouja_dynasty> [13](https://en.wikipedia.org/wiki/Ningthouja_dynasty) <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html> [1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) I am not very familiar with the dynasties of south India and I am not certain about how much the Ningthouja Dynasty was a single dynasty. 3) 2,250 or 1,950 pr 1,945 or 1,545 years. The Pandyan Dynasty reigned in southern India for a very long time. Apparently they reigned on and off in various parts of south India for about 1,545 to 1,950 years from the 3rd century BC to 1345 and 1650 in various regions. Some sources say the Pandya Dynasty reigned for 1,945 years from 600 BC to 1345 or about 2,250 years from about 600 BC to 1650. <https://en.wikipedia.org/wiki/Pandyan_dynasty>[14](https://en.wikipedia.org/wiki/Pandyan_dynasty) <http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html>[1](http://www.thelanguagejournal.com/2012/12/top-10-dynasties-in-world-that-reigned.html) I am not very familiar with the dynasties of south India and I am not certain about how much the Pandyas were a single dynasty. 2) 2,678 years, or 1,511 years, or 1,479 years, or 1,447 years. The Yamato Dynasty of Japan. The traditional start of the Yamato Dynasty of Japan was in 660 BC. But Kinmei, the earliest ruler considered totally historical, reigned from about 539 to 571 AD, from about 1,479 to 1,447 years ago. Kinmei was the son of Keitai who supposedly reigned from AD 507 to 531, beginning 1,511 years ago. Keitai was allegedly a 4th cousin of the previous ruler Buretsu (reigned c. 498-507), both being descended in 5 generations from the legendary Ojin who supposedly reigned from about AD 270 to 310. But skeptical historians wonder if Keitai was an usurper unrelated to Buretsu. If so, that would make the Yamato dynasty only 1,511 years old since 507. If Buretsu and Keitai were actually members of the same dynasty then it's history would go back generations before AD 507, but probably would begin centuries after 660 BC. 1) 2,880 years, or 2,544 years, or 1,830 years, or 1,494 years, or 1,421 years, or 660 years, or 654 years or 581 straight years. The Solomonic Dynasty. The Solomonic Dynasty ruled and/or reigned as Kings of Kings of Ethiopia for 581 years from AD 1270 to 1851 when Yohannes III (c. 1797-1873) was deposed at the end of his third reign. Tewodros II (1855-1868) claimed, very doubtfully, to be a member of the Solomonic Dynasty. Tekle Giyorgis II (1868-1871) claimed to be descended from the Zagwe Dynasty that ruled from about 900 to 1270. Yohannes IV (1871-1889) claimed to be descended from the Solomonic Dynasty. Menelik II (1889-1913) was a member of the Solomonic Dynasty. All later monarchs until 1975 were descended from the Solomonic Dynasty only through female lines except for Zewditu (1916-1930) who was Meneleik's daughter. So if all claimed membership of the Solomonic Dynasty was true it would have ruled for 598 years from 1270-1868 and for 42 years from 1871 to 1913 and for 14 years from 1916-1930, for a total of 654 years spread over a span of 660 years. But the Solomonic Dynasty claimed to be a restoration of the dynasty that ruled the Auxumite Kingdom from about AD 100 to about 940 when it was overthrown. So that adds about another 840 years to the claimed duration of the Solomonic Dynasty, extending it to 1,421, or 1,494 years spread over about 1,830 years. But there's more! The Solomonic Dynasty claimed to be descended in the male line from King Solomon, who traditionally reigned from c. 970 BC to 931 BC, and the Queen of Sheba, through their son Menelik I who became the first monarch of Ethiopia. Therefore the claim of the Solomonic Dynasty is that it ruled Ethiopia for about 1,890 years since about 950 BC to about 940 AD, and again for 598 years from 1270 to 1868 AD, and for 42 years from 1871 to 1913, and for 14 years from 1916 to 1930, for a total of about 2,544 years spread over a span of about 2,880 years. Believe it or not. [Answer] 1. Make sure the kings have sons. Polygyny (only for the king and his children, since widespread polygyny means there are a lot of young men without wives, and that leads to violence and instability). 2. Don't intermarry too tightly. (EDIT: so that you don't get many weak and feeble.) 3. Weed out the weak and feeble that *do* occur. 4. Buy the loyalty of the aristocracy, civil service and army without taxing the peasantry *too* hard. 5. Transition to a constitutional monarchy so that there's no burning desire on the part of powerful aristocrats to overthrow the monarch. [Answer] There are two primary roadblocks for a continued rule by a single hereditary line, both of which boil down to natural selection: 1. Genetics. Over time, a select hereditary line, however careful, is going to accumulate genetic deficiencies that will eventually render its members incapable of continuing their duties as rulers. [King Tut](https://en.wikipedia.org/wiki/Tutankhamun#Genealogy) and [Tsarevich Alexei](https://en.wikipedia.org/wiki/Alexei_Nikolaevich,_Tsarevich_of_Russia#Hemophilia) are notable examples. 2. Since dynasty members are born into power rather than choose it on their own will, there's going to be an inevitable fluctuation in their ability and willingness to wield it. As such, you're going to somehow counter these factors. These are the ways tried out in history, with varying degrees of success: * Somehow look out for people capable of and willing to take the lead and adopt them (countering the genetic trap by making heritage in-name-only). The main trapping here is that selection was generally done from nobility rather than everyone -- which, if becoming a closed caste, still opens itself to degradation by inbreeding. * Limit/distribute the power of the monarch thus eliminating them as a single point of failure, reducing the load of responsibility on and thus ability requirements for them. This was tried out in Japan where for many centuries emperors were figureheads. You may notice that this both is exactly what more democratic regimes are doing... [Answer] I suggest you to allow your king to adopt the best man in your kingdom like the roman empire in III B.C., it allow you to ever have a strong king on the throne; to ensure that your king can't choose someone not suitable for the job, the heir have to do a some kind of "cursus honorum" (he had to serve in the military and in public position), so he would be prepared for rule a kingdom; therefor your dynasty will remain intact for a long time, because the adopted heir would inherited not only the throne but also the dynasty surname and all the wealth of the family. For the religion i suggest you to be inspired by Asian religion or Greek and Latin paganism, because they are more like philosophy; the people subjugated from your kingdom will more likely embrace this kind of religion. This empire can't stretch to much but he have to rule in his cultural region like Chinese and Japan empire. Or if your world is fantasy you can use something like the dragons in game of thrones to keep cohesive your kingdom, indeed a threat like this can certainly keep your empire strong and your dynasty live easily 1000-2000 years. [Answer] > > Japan's Yamato dynasty traces its origins back to 660, making it the oldest continuous hereditary monarchy in the world. ([Source](https://www.washingtonpost.com/news/worldviews/wp/2013/07/22/meet-the-worlds-other-25-royal-families/?noredirect=on&utm_term=.157cdf649ea0)) > > > That's almost 1,400 years. * Rules of inheritance/heredity that produce an ordered transition of power within the dynasty should the monarch not have children. For example: oldest child of the monarch (and each child in turn), then oldest sibling of the monarch (and each sibling in turn), then oldest aunt/uncle (and each aunt/uncle in turn), then oldest child of oldest sibling (then each in turn for each sibling in turn). Frankly, that ruleset alone guarantees the dynasty. * Require spouses (and, therefore, children) to take the name of the dynasty. * Have tons of loyalty & firepower. I should think if you successfully have all three rules one would keep any dynasty alive forever. [Answer] You could use a shared identity or common enemy as a way to unite the people in favor of their country, and that could easily distract the average citizen from any mistakes the government makes, which would lower the chances of rebellion or major social change. That could also make the dynasty resistant to external forces because nationalism would increase interest in fighting and defending for their country. [Answer] I would turn the question around, to start with. The question to ask is, what causes a dynasty to *end*. My presumption is that **dynasties succeed and endure by avoiding the many causes of failure, rather than by targeting causes of success**. There are also some protective factors, which seem to be much more limited in scope. # Protective factors * How the rulers are seen by the populace. Think of Japan's near godlike but apolitical position on emperors, or the sanctity given by Thais and Muslims even towards *images* of their king and Prophet respectively. * The supporting structures available to the rulers. Think of nobility, priestly castes, law, military, or trading classes (plutocrats), who may provide much of the stability behind the throne. * Resources available to the throne. If the ruler dominates some types of resources or rights, or has some kind of ability or power (technogical or magical). * External/survival threats. These tend to bring people together. Interestingly they could be natural as well as human. For example, ongoing threats from natural forces (sea, volcano, famine etc) may push revolt into second place behind survival. * Power structure - this is separate from supporting structures. Think of a slavery based classical society, these were often quite stable, even though to us, slavery is abhorrent, because *enough people benefited and were placed in a position of power*, to the extent that they had a vested interest in perpetuating it. Slave revolts occurred, but the rest of the society largely repressed them. * Satisfaction of population. If the population feels broadly happy/content, the public motivation to support a change of status quo diminishes. This could relate to ignorance of alternatives, or knowledge, or living standards, or population pressure, if they feel their voices are heard (somehow), etc. * Fears of populace or of supporting groups. If some extreme fear exists in the minds of either the populace or the supporting classes, this can readily inhibit efforts towards change. This might relate to the ruler's reputation for discovering plots, the fate of rebels and their families, the extent of informers within society (ease of trust) - this could be spies but could be as simple as a religious confession ritual, fear of divine retribution (in this life or the afterlife), "vanishing" of people, etc. * Beliefs of the society, and how they interpret and act on these, and how seriously breach is taken. For example, is "kindness" felt by (almost) everyone as a core value that is essential to live by ("walk the talk")? What about concepts like "honour"? "Power"? "Generosity"? "Faith"? "Family"? ... # Causes of failure History lists quite a few obvious answers, and beyond that there are probably also meta-observations. This can't ever be a complete list, and there's no "best way" to categorise these. The list is probably huge, but this is where I would begin. I wouldn't be surprised if historians have formally written books or papers analysing this. They would do a far better job than I could. One meta-feature I would add is to consider flexibility vs. rigidity: *Assuming a dynasty that has shown it can last for centuries*, does that dynasty have a better chance of extending its rule to *millennia*, if it (and its society) is rigid, or if it is flexible/adaptable, or some combination? [Answer] **Choose the right king at the right time** Each lord chooses an apprentice who will take control before the king dies. An apprentice as others have commented reduces the danger of the first male being incompetent or unwilling to rule. The importance of the king passing control over before his death is so he does not grow too frail to lead and so the powerful ruler is still able to return from retirement until people have got used to the new ruler and he has learned how to rule well. **Don't allow lords real power** Each lord should have only part of the power of a province. One controls food and natural resources, one controls military, one controls the money, one controls the navy. This would make it difficult for a province to rebel without unanimous support of the lords as each lord would be powerless alone. You could further the divide of powers by having each type of lord learn a different language from birth and be banned from learning others so they are only able to communicate through randomly assigned translators. That way the lords would not be able to communicate with each other in secret. Alternatively you could have each province only allowed to train one type of soldier. Province 1 and 2 have infantry 3 and 4 have cavalry, 5 and 6 have archers and 7 and 8 have canon, then if there was a rebellion of fewer than half the provinces the rebels would have an army very reliant on a particular set of tactics giving a huge disadvantage, in addition to having to trust the other rebels to a greater degree. The king could keep control of a personal force which covers all arms so the king will never be without a tactical option. [Answer] Ancient Egypt was well protected from invaders by the deserts surrounding it. If you have a logical reason that invaders would not be able to get to the country in sufficient numbers to invade it, you can justify an absurdly long dynasty. The problem is your gap in the mountains. If the mountains are treacherous enough, they can stop potential invaders, but the gap lets anyone just waltz in and take over. **How to mind the gap** However, using magic, you can protect the gap area. The first things that come to mind is a force field to stop people from crossing there. The problem with a boundary is that it cuts off trade. If your country will be self-sufficient, I would recommend not having trade, as hiding from the rest of civilization will make your country less of a target to potential invaders. If you have to trade, though, a semi-permeable force filed would work. Remember, a couple bad guys sneaking in is not a big threat, and anyone who is determined enough can scale the mountains. You just have to protect yourself from big armies. **The force field** The force field can be made from a magic item, it can be a force of nature, or it could be maintained by a group of wizards who take turns maintaining it. If you hide away (you don't engage in trade), there is no logical reason for your force field to go down, and you will not need a military. If an army somehow manages to invade though, you will not have any weapons to fight with and you will just be throwing rocks at the invaders. Probably not the most convincing or interesting story line. If you don't hide, that is a good reason why your force field would go down and also a good reason why you would have a military and weapons- to fight the bad guys who sneak in over the mountains or stow away in incoming shipments or pose as merchants. One of them could take out one or all of the wizards maintaining the field so that the larger army can come in and attack. Keep in mind that this option still leaves the option of exactly what you are trading and the details of your magic open, you might need the ability to choose the specifics later on. [Answer] I think it's a fool's errand to try to design an institution of monarchy that cannot fail -- history is full of unknown unknowns ("black swans") that cannot be planned for, and you cannot prepare for everything. Instead, try to establish **resiliency such that your dynasty will keep coming back** no matter how many times it is overthrown, deposed, exiled, or what have you. One thing that you have, by virtue of being a thousand year dynasty, is *legitimacy* in the eyes of at least some of your subjects. Any temporary political party or military junta may have *power* but not *legitimacy* -- they'll only keep power as long as they can fight for it. But your descendants can "bless" these short-term rulers by claiming that they rule in your name. This is a win-win; it keeps your dynasty relevant and gives your descendants at least *some* limited power to make demands, and for the short-term powers it gives their own dynasties a longer lifespan. When they inevitably fall, your descendants give their blessing to the new power. Your dynasty's power may seem very little, if it's limited to a purely ceremonial role, but that's only when viewed from the perspective of a single lifetime. In a single century, a figurehead royalty cannot do much, but if they have the cunning and the patience to shape affairs over millennia, and the (admittedly bizarre) personality that allows them to view things from that perspective, they may be able to do quite a lot of shaping of their nation's future. [Answer] You need cognatic sucession, to avoid extinction due to lack of males, polygamy, to avoid extinction due to lack of children, to forbid close kin marriage to avoid a Charles II of Spain, the hability to jump to cadet branches like the modern Saudis or the old Japanese did, a religous role to the emperor that can be detached from the politics (like in Japan). Also you must have a way to get rid of the excess of royals that your system will generate. You should avoid marriages with your dukes and with neighbours, to prevent claims and wars of succession. Maybe you could send your excess royals to die fighting in the outside world as mercs or conquerors. Maybe you could sacrifice them to gods in pyramids - that would link with the religious role that your dinasty has. [Answer] # History editing The Party has been in power for thousands of years, every history book says so ! Introduce subtle indoctrination gradually and after a couple generations, everyone will believe it ! [Answer] There was king know as Ventheir Chezhiyan Pandyan from Pandya Dynasty of INDIA ruled in 6000 BCE. If evidence solely derived from ancient literatures or text then Pandya Dynasty was the oldest & longest in the entire world having ruled circa 6,000 BCE to 1665 AD almost 7,665 years mention. Ventheir Chezhiyan Pandya was clearly mentioned in ancient Sangam Tamil literature! [Answer] I'd try to be original and also attempt to lean on the coup d'etat tradition in some Near East countries. # A rule to change the dynasty It might be quite hard to have a dynasty in the actual power, with somewhat usual inheritance rules (male children, all that), and for a longer period of time. Even harder it is to make it survive coups and dictatorships. What about insane kings? Pretenders? Habsburg-level incest? So, in a sense, an easier way is to fix not a dynasty as such. But a rule to *change* the king/dynasty can be fixed. Let it be some kind of Divine Mandate (hello, China) or the traditional gist and upbringing of army generals. In the latter case: if the ruler does not satisfy the long-standing traditions, he is... well, replaced. And traditions can be enforced quite easily, such structures as tradition-infusing military academy survive for centuries. So, you basically need some vehicle to pronounce a new king a true one. It might be a really existing creature (hello, "Twelve Kingdoms"!) or just some kind of a superstition, such as "who has the larger army and yeniçeri support wins". Or "who was chosen by the people". An example when a chain of rulers is not related by blood is the Pope election or-- yeah, a democracy. ]

[Question] [ My main character is one of 5 deities that make up the "Terram faith" The country she resides in is a theocracy of that faith; with a king and queen appointed by high priests and priestesses. The issue I'm having is usually in theocracies people with other beliefs were at risk of persecution etc. & that doesn't align with her character. How could a theocracy work if they are tolerant of people worshipping outside of the ruling religion? [Answer] The best way to make your theocracy reign while having freedom of religion is to consider your religion to not be a religion. If you treat your religion as a proven fact, and define religions as beliefs contrary to or alongside the truth that is your god(s), you make it into a matter of accepting the truth. In this way, you relegate other religions to a conspiracy theory, an unproven or untrue belief. If your religion is actually not a religion, and religions are actually just fake news, you can easily have freedom of religion. You have no state sponsored religion, so the priests are just state workers, who are responsible for appeasing the god(s). You can set up religious freedom as a first amendment right. If you want to go even farther, you might want to see [this question](https://worldbuilding.stackexchange.com/q/123122/54384) about limiting religion. The question asks how to limit religion in the society, and there are some really interesting answers there. You can actually exclude followers of any other religion from becoming a leader on the basis of freedom of religion. Political leaders are undoubtedly influenced by religion, which makes them a puppet of their gods and religious leaders. In your state it is necessary to have leaders with no religious ties so the leader focuses on the common good. You can use the above point to get rid of anyone the religion doesn't like. All that you have to do is spread rumors that the candidate was observed praying to a false god. Then you launch a fake investigation, conclude that the candidate was in fact lying about their religious affiliations, and throw them in jail for collusion. You can get rid of leaders in other religions in this way too. Just claim that they tried to manipulate a candidate and you can lock them up too. [Answer] First, as already covered in [this answer](https://worldbuilding.stackexchange.com/a/128456/28), a theocracy can be more concerned with people *following its rules* than with people *following its god*. Historically some Muslim rulers were like that, such as the caliphs in al-Andalus (modern-day Spain) in the 10th-11th centuries. Second, your religion(s) might practice [monolatry](https://en.wikipedia.org/wiki/Monolatry) or [henotheism](https://en.wikipedia.org/wiki/Henotheism) rather than monotheism. That is, they might accept the existence of other gods (and thus their worshippers), while considering them inferior to The One Important God (your deity character). Examples of such religions from our world include Zoroastrianism, Hellenism, (some?) Hinduism, ancient Egyptian religions (where the *pharaohs* are gods but not the only gods), and other religions of the Ancient Near East. Third, your religions might hold that different gods rule different geographic areas. Your deity is the local one and most important in that place, but maybe some of the people living there came from elsewhere and maintain family traditions connected to their original gods. So long as they're not interfering with the dominant theocrats, that might be fine. Your theocrats might even see them as charity work -- we have to help those poor people who haven't yet come over to (insert your deity here). [Answer] It seems like the main issue wouldn't be people who practice other religions. It would be people who refuse to follow the rules of the theocratic religion. It's likely that there would be many laws in that nation that someone who didn't adhere to that religion would disagree with. If someone came to that country and refused to follow those laws, and was punished for it, would you consider that to be an instance of being intolerant of people worshiping outside the ruling religion? (And, perhaps more to the point: would other people in that setting consider it intolerant? Would the person being punished consider it intolerant?) As an example, imagine if they had dietary laws that were actual political laws. Would it be intolerant to send someone to prison for eating bacon? Because that seems like the sort of thing that might happen in a setting like this. (I'm ignoring the degenerate case where there's officially a state religion but in name only, such as the Church of England.) [Answer] Certainly you could write such a theocracy. Judaism is believed to only pertain to people who are ethnically Jews. A Jewish theocracy would not attempt to compel people of other ethnicities to convert. The kingdom could view religion as tied to heritage and expect foreigners who move into the kingdom to practice the religion of the foreigner's homeland. For that matter, many early polytheistic faiths had this point of view. A Roman would not think it odd for a Parthian to worship the Parthian gods. They often allowed conquered people to worship their own gods. This works even better if ancestor worship is an aspect of the religion. In many African tribes, for example, part of the reason for practicing religion was to honor the ancestors who had passed down those beliefs. <http://www.crf-usa.org/bill-of-rights-in-action/bria-13-4-b-religious-tolerance-and-persecution-in-the-roman-empire> [Answer] We have examples of theocracied both in real life and fiction, in which the ruler is appointed by priests, and which are accepting of other cultures and faiths. In real life, the Tibet is ruled by the Dalai Lama, and the Vatican is ruled by the pope. As for the latter, say what you will about catholics, but the vatican has been spreading a message about peace and love for quite some time now. In fiction, Aang from the Avatar series lived in a theocracy under the rulle of an abbot. That is based on real life Tibet. [Answer] I have heard the Mongols described this way—I have my doubts about that characterization being historically accurate, but it is *plausible* so even if the Mongols weren’t actually, your people could be. Basically, the description I have heard is that the Mongols believed that the spirits of their homelands demanded conquest from them, which they did. They conquered far and wide, and never made any attempt to convert anybody—the spirits they followed were intrinsically tied to the places they came from. People who had never been there couldn’t worship them and it wouldn’t make any sense for them to try. Instead, it was assumed they would just go on worshiping the spirits of their own places—which were no threat to the Mongols’ spirits, obviously, seeing as the Mongols conquered the place to begin with. So consider the possibility of a ruling class that is a theocracy, but for theological reasons has absolutely zero concern about what the non-ruling classes do or do not worship. In fact, the non-ruling classes may well be considered *ineligible* for worshiping the ruling class’s god(s), and attempts to do so may be seen as sacrilege and/or treason. [Answer] Consider the Ottoman Empire as an historical example. Despite being a Muslim empire ruled with fairly stringent religious conditions, they permitted Jews and Christians to consider practising their faiths -- the status of "People of the Book" denoted that they were seen as similar enough to Islam to be allowed to exist. While they were allowed to exist, they had other restrictions on them: the Patriarch of Constantinople, for instance, now had to be approved by the Sultan after his nomination; and non-Muslims were subject to an additional tax because of their faith. This is likely how religious plurality would be expressed in a fictional theocracy. [Answer] The United Kingdom is an example of a modern day theocracy. Queen Elizabeth II is the [head](https://en.wikipedia.org/wiki/Church_of_England#Structure) of the Anglican church: > > The British monarch has the constitutional title of Supreme Governor of the Church of England. The canon law of the Church of England states, "We acknowledge that the Queen's most excellent Majesty, acting according to the laws of the realm, is the highest power under God in this kingdom, and has supreme authority over all persons in all causes, as well ecclesiastical as civil." > > > I daresay that the UK doesn't persecute anybody who does not follow their particular branch of christianity. This would be an example of rulers just not caring all that much about what religion their subjects practice. In a different, more historical perspective, Muslim countries were generally tolerant of [People of the Book](https://en.wikipedia.org/wiki/People_of_the_Book). Anyone who was considered 'of the book' but not muslim was given specific rights and duties, and generally allowed to practice their religion in relative peace: > > Dhimmi is a historical term referring to the status accorded to People of the Book living in an Islamic state. The word literally means "protected person." According to scholars, dhimmis had their rights fully protected in their communities, but as citizens in the Islamic state, had certain restrictions, and it was obligatory for them to pay the jizya tax, which complemented the zakat, or alms, paid by the Muslim subjects. Dhimmis were excluded from specific duties assigned to Muslims, and did not enjoy certain political rights reserved for Muslims, but were otherwise equal under the laws of property, contract, and obligation. > > > So, how might you use this in your world? As others have suggested, you could have the rulers simply not care about what the plebeian masses believe. Alternatively, you could have your rulers be tolerant of anyone who practices the Terram Faith, whether their specific version of the religion matches that of the ruler or not. [Answer] * [Theocracy](https://en.wikipedia.org/wiki/Theocracy) is a government where a deity/religion is the source of political legitimacy. * Freedom of belief and freedom of worship (keep in mind that those are related but distinct) are the ability of individuals to hold and express other religious beliefs than those approved by the state. Look at the history of both religious and political liberty in Europe. First there were the Catholic church and the pope, who would at least in theory have to confirm rulers. Then there was the principle that the ruler set the branch of christianity that was permissible, [cuius regio, eius religio](https://en.wikipedia.org/wiki/Cuius_regio,_eius_religio). After some bloody wars, there was the [Peace of Westphalia](https://en.wikipedia.org/wiki/Peace_of_Westphalia) which, among other things, allowed christians to believe and practice other branches of christianity. This did not yet abolish the role of bishops as temporal rulers, e.g. in [Electorate of Trier](https://en.wikipedia.org/wiki/Electorate_of_Trier), which only happened by the Napoleonic wars. The religious Electorates were no clear-cut example of a theocracy because their rulers "wore two hats," so to speak, but you can look at them as a pattern. [Answer] A small but relevant historical example: During the First Crusade, one Crusader army decided that, hey, [why go all the way to Jerusalem to kill armed Muslims when we have defenseless Jews right here?](https://youtu.be/HIs5B2U7US0?list=PLhyKYa0YJ_5Aq7g4bil7bnGi0A8gTsawu&t=339) Which is described in this video as the first large-scale antisemitic pogrom of Europe. Which the Catholic Church apparently really, really didn't like. To the point that some bishops - which, having temporal powers, were basically local theocratic lords - went to great lengths to try and protect their Jewish populations, including military action. So yes, a theocracy can indeed be tolerant of other faiths, and go pretty far to defend said tolerance. [Answer] Certain nations consisted primarily of people persecuted for their faith, thus making them less eager to persecute others in the same way. Examples of this to various extents are for example the united states and the Netherlands. > > Because the Netherlands had ceded from Spain over both political and religious issues, it practiced certain forms of tolerance towards people of certain other religions and opened its borders for religious dissenters (Protestants and Jews) from elsewhere, while maintaining its persecution and later discrimination against native Catholics. Descartes for instance lived in the Netherlands for most of his adult life. > > > Source: Wikipedia article about History of Religion in the Netherlands I picked the above quote specifically because it also highlights that this freedom wasn't in any way absolute. Especially Catholicism had it hard in certain parts of the Netherlands - the parts that were hurt most under the Spanish catholic persecution - , but at the same time it was primarily "just" discrimination. Anyway, the end result was a society which created a culture of "do whatever you want as long as it doesn't affect others and isn't *too* different morally". What was "too" different was a bit flexible though, but as far as my limited knowledge goes atheists, Jews, Muslims and most of the different Christian denominations had it fairly "well", but Catholics and some of the more extreme "Christian" sects had it harder. Although the Dutch traded a *lot* with the far east I have no idea how Asian religions were treated in the Netherlands as I think few people traveled from those parts to Europe. Anyway, leaving the history of our world aside, from a world building point of view this is an easy motivation you can give a nation to be comparatively tolerant towards other religions and it also allows you to balance how far this will go. If your MC is a deity of flowers and there is another deity of plainness that is all about trampling all flowers in the world then it's going to be incredibly hard to justify that those would live together, but as long as the "let us both do our own thing as long as we don't interfere with each other" can be upheld it's quite possible to have a strong theocracy which still welcomes other religions. [Answer] You should take a look at [the questionable burdens of leadership of a troll emperor](https://www.fanfiction.net/s/10917821/1/The-questionable-burdens-of-leadership-of-a-troll-Emperor). This is an example of a successful theocracy with freedom of religion. This works because the ruling deity is *actually a real god*, and as they would put it, their divinity does not depend on whether people believe they are god; whether people believe or not, they will continue to exist and be divine regardless. As a result of their divinity being a clear brute fact, their people tend to just accept them as a fact of life. If anyone was to try and worship a different god, they would be allowed to, but consider to be a little bit strange; maybe even mentally unstable. Like people in our world believing the earth is flat - there's no law against believing in, but it's a bit weird. Since your question suggests the gods in your world area also real, you can quite easily just make it a background fact that they are the only ones worshipped. Like how google is the only search engine most people use - yes, hypothetically askjeeves might be around somewhere, but it doesn't matter; people don't 'askjeeves' things, they 'google' them. So in your world, people don't 'pray to zeus', they just 'pray'. The 'to zeus' but is taken for granted, because who else would they be praying to? Thor? Oh yeah, I heard he's one of those gods those weird foreigners worship... TL;DR: People of other faiths only get persecuted if those faiths are equally valid. If heretics get struck by lightning, there will very quickly not be any heretics left. No need to break out the toches and pitchforks when you can just sit back and watch the show. [Answer] The answer to this question differs between "true" theocracies where the religious leaders are also the secular leaders and theocracies which just legitimizte the secular leaders. A "true" theocracy, like the historical Muslim *Iqta‘* system where the religious leaders were also the secular leaders, can actually get around with not everyone following them. Their power comes from their armies, not their moral authority. They don't care if people believe in them, because those who do not believe that it is God's will that they follow the Caliph can be convinced by force. On the other hand, a theocracy which just legitimizes the kings or queens but doesn't wield any direct power, like the Catholic church in the medieval age for example, is much more dependent on faith. Their whole authority is derived from the fact that the majority of the population believes in them. When they are no longer the majority religion, the church no longer has the authority to appoint rulers. Also, the rulers have no longer a reason to seek the approval from the church, because the majority of their underlings wouldn't care about the opinion of the church anyway. For example, consider the following scenario: The king gets into an argument with the priests. So the king declares that he decided to convert to a different religion. The priests have no power over him anymore. He tells his guards (who aren't Terram faithful) to throw the priests out of the castle. How would the Terram priesthood react to this situation? The first reaction would likely be to declare that the king is no longer the king and that they appointed a new one. But then what? How do they put their new king in power when the old one controls the army? Tell the peasants that the king is no longer the king, that they should to take up arms, slay the heathen and enforce the divine right of the new king? Good luck with that if most peasants have a completely different religion and thus no reason to listen to the Terram church at all. So if you want a theocracy with true power, either put it in control of the peasants or put it in control of the army. One thing you could try which wasn't (afaik) ever done in real-world history would be a combination of theocracy and military shadow-dictatorship. Put the priesthood in control of the army. Have them turn all soldiers into religious fanatics. Let the soldiers swear allegiance to the gods and their priests, not to the king. Now even the king doesn't need to be all that religious, because if he ever acts up against the will of the priests, his own soldiers will turn against him. [Answer] Similarly to other answers, I think the main solution surrounds what, exactly, your theocracy stands for. However, the other answers gloss over the heart of the matter, which is what, exactly, you mean by 'tolerance', and what the goals of your theocracy are. --- TLDR: Your theocracy must stand for some set of beliefs that no one (or almost no one) in the kingdom is actually willing to disagree with - it'd probably be best if it's something that isn't even taught, or codified, but just how things *are*. It can then proclaim tolerance by not caring about anything anyone believes, so long as it doesn't contradict those unspoken base beliefs. It will look tolerant, so long as most people don't disagree with its **core** principles. To be tolerant of disagreement with your core principles, however, is to show that those aren't actually your core principles. --- At some level, I strongly submit that every person has a set of beliefs that they believe are true for them, but not necessarily something that others should be forced to follow, and *also* a set of beliefs that they consider universal, that can't be compromised on, and that others should be compelled to adhere to. I will define the first set of things as "disagreements a person is willing to be tolerant of", and the second set as "disagreements a person is not willing to tolerant of". There is *always* something in that second set. For most of the west, I think that core moral belief can be boiled down to "don't hurt innocent people", and/or "try to make everyone who matters to you happy". People proclaim tolerance towards anyone who follows those principles, and generally refuses to tolerate any actions that go contrary to them. There aren't really any cries for 'tolerance' towards people who thinks beating their spouse is OK, regardless of whether or not the spouse complains. Nor does anyone proclaim tolerance for people who think murder is OK, or rape, or animal abuse. Most tolerance, is merely the state of holding moral views whose core beliefs don't conflict. The only way a person, being, or government, can truly tolerate *everyone*, is if they don't believe *any* actions to be fundamentally wrong, and worth preventing or fighting against. Therefore, your deity's tolerance must be limited. At some level, if two people have beliefs, *and those beliefs contradict*, then each person must decide whether or not the issue is important enough to try to force the other person to change their behavior. Tolerance is saying "this isn't important enough to force". ## A theocracy, though, which doesn't believe that there's anything important enough to compel or force, is not\* a theocracy. --- \*Perhaps you could get around this with a religion that expressly disbelieves in the concept of 'right' and 'wrong'. Not moral relativism, but the actual absence of those concepts. If you take that path, I'd advise avoiding contact with anything your reader might feel strongly about. The rest of this answer ignores theocracies that don't believe in the concepts of right and wrong. --- If you want a theocracy that can proclaim tolerance, then, you'll have to make the things it *really* cares about something that most people never interact with, or are at least all willing to submit to, and that doesn't touch the things people could actually disagree with. Note, however, that tolerance can only be proclaimed by contrast - it isn't "tolerance" to let people do things you don't care about. It's only tolerance if you're letting people doing things you disagree with. Your theocracy therefore needs to assert two classes of beliefs: one that it doesn't really care whether the people believe or not, which it can claim to be tolerant about, and another (possibly hidden) that it does care about, which doesn't really impact anyone. You may find the concept of doublethink necessary. --- Other answers brought up conquering nations that allowed their subjects to continue practicing whatever they wanted. That's an example of a group being 'tolerant' about things they don't care enough about to force, so long as the subjects do the thing the conquerors *actually* care about - paying tribute, or not taking up arms against them, etc. [Answer] The kind of theocracy you’re thinking of is a country ruled by priests, with “a king and queen appointed by high priests and priestesses.” That kind of government can easily tolerate things like people worshiping on a different day of the week, celebrating different holidays, or following different family laws. Although the Abrahamic religions teach that it is morally wrong to practice “idolatry,” the religions of East and South Asia traditionally don’t, and you might take inspiration from the relationship between priests and rulers in Hinduism or Buddhism. Some things that might test the limits of tolerance, even there: * Do other religions have formal rights granted by the theocracy? * Does the state actively intervene to protect them when someone else persecutes them? * Does the theocracy have client states with a different religion, like ancient Judea under the Persians or Romans? * Is there a list of tolerated religions, as traditionally was the case in Islam, or a broad principle of universal religious tolerance? * Can the same person have multiple religious identities at once (the way a Buddhist might also practice some other religion), or are they exclusive? * Does the state religion make a strong claim that other religions are false or evil? Is it basically compatible with some of them, but not others? * Are there any minority religions that just don’t get along? * Would it make sense to someone from this culture for a bride and groom to have different religions? Is there even such a thing as civil marriage, or would they need to find some priest willing to marry them? * Are important community events (like coming-of-age, marriage, funerals, holidays and charity) considered religious in this culture? Could someone participate in their community without participating in some “religion?” * Is a “religion” a *community*, or a personal opinion? If you attend all the major events at the Temple of Alice with your family and have for your whole life, but say, “I don’t think the priests of Alice know what they’re talking about,” do you count as belonging to the religion or not? * What form of discipline is there for heretical priests of the state religion? * If laity of the dominant religion reject the authority of the hierarchy, what happens to them? What if they reject the entire government? * Are there any “religious” duties that are not optional, such as swearing an oath to the King and Queen, serving in the army, or paying taxes? * Do any religions tell their followers to do things that cause problems? * Were there any exceptions made for what were originally just a few people, but which have become unsustainable? Is it possible to change them? * Are there a lot of people willing to take advantage of the principle of religious tolerance manipulatively, or is there strong social pressure against that? * Do only long-standing traditions have protection, or can a religious leader make a new rule that exempts his followers from royal law? * Are the existing Temples of Alice only allowed to keep going in Alicetopia, or can Alicetopian migrants build a new one elsewhere? * If there’s a schism in the Temple of Alice, who decides which Priestess of Alice gets the Temple? * Can Bob say, “Hey, I just talked to an angel, so now I’m the Prophet of the Church of Bob,” and be recognized as in some sense equal to a religion that’s existed for thousands of years? * Are people allowed to leave the state religion? Are other religions allowed to actively proselytize? Is conversion only allowed in a few special cases, such as marriages? * Do people believe that witches or evil cultists are committing crimes and must be stopped? * Are any foreign religions perceived as agents of a hostile power? * Is religion ever a proxy for an ethnic group or political faction? [Answer] Practical example: Brigham Young hired nuns and priests to set up schools in Salt Lake. While Utah was not legally a theocracy, in fact the elders of the church had a lot of say in government. Salt Lake had almost as many Roman Catholics as Mormons at one pont. I went to school for a semester at Brigham Young University in Provo. Provo is 95+% Mormon. (In a city of 100,000 people there are two churches -- one catholic, one methodist that aren't mormon) The influence of the church is such that there are no restaurants, only a few drug stores and one grocery store open on Sunday. I didn't drive, so I don't recall about gas stations. If one religion dominates in numbers, then there customs will affect the entire culture. [Answer] > > The Druze still do not permit conversion, either away from or to their > religion. Marriage outside the Druze faith is rare and is strongly > discouraged. Many Druze religious practices are kept secret, even from > the community as a whole. Only an elite of initiates, known as ʿuqqāl > (“knowers”), participate fully in their religious services and have > access to the secret teachings of the scriptures... > > > [Source](https://www.britannica.com/topic/Druze) Neither [Druze](https://en.wikipedia.org/wiki/Druze) nor [Zoroastrianism](https://en.wikipedia.org/wiki/Zoroastrians_in_Iran) accept [converts](http://www.iranicaonline.org/articles/conversion-vii), you have to be born to a worshiper in order to join (in the case of Zoroastrianism, both parents must be members). It might be possible for your theocracy to be similar - they run the country and perhaps a large amount of the population is of the same faith, but foreigners cannot join. They neither hate nor disparage those of other faiths. Prior to the Age of Enlightenment, *[cuius regio, eius religio](https://en.wikipedia.org/wiki/Cuius_regio,_eius_religio)* (whose realm, his religion; meaning "I'm the boss, you worship my way") was the predominant view. If the Monarch was a Catholic, you better convert. The first treaty to change that was the [Augsburg Settlement](https://en.wikipedia.org/wiki/Peace_of_Augsburg). This treaty allowed for a modest freedom of religion in the Holy Roman Empire, now you have [both kinds](https://www.youtube.com/watch?v=vS-zEH8YmiM): Catholic and Lutheran. [A later treaty](https://en.wikipedia.org/wiki/Peace_of_Westphalia), ending the Thirty Years War allowed for more choices and created the major principles behind "what is a country", international justice and order. Perhaps your world has had similar wars of religion settled by treaties. [Answer] The Roman Empire was pretty much that. Romans believed they had a deal with their gods: the Romans would build temples and make sacrifices, and in return the gods would look after Rome. Individual citizens were pretty much free to believe and worship as they wished. It was only towards the end that the bureaucracy started imposing sacrifice quotas and the early Christians refused to play along. [Answer] It *can* but probably won't. All"-cracies" are political entities. The basis of politics is to maximise one's own influence, while minimising that of competitors. Religious institutions, especially political ones, only peacefully coexist when: 1. there are many of them of similar levels of influence; and 2. there is a strong secular polity they need to watch out for. [Answer] Your realm is different from real world theocracies in that your deity is actually present and active. Governments generally become oppressive when they feel threatened. Rulers backed by a active deity has very little to feel threatened by, unless another deity is trying to take over. The ruling class will come from the priesthood of the deity in control. As long as people of other religions accept that, they can worship whoever they want. There is likely to be *some* friction. The ruling religion will have some rules of conduct. Breaking these rules IN PUBLIC might be considered indecent behaviour, even if the person follow another religion. In private things should be more relaxed. Again, a ruling deity can decide what they want. They can choose to say "Beards are icky, I don't want to see them on anyone." OR they can choose to say "MY followers should shave, but others can do what they want." Either way, the priesthood will have to go along. ]

[Question] [ In the modern world, the technology to monitor your every movement and action is imminently feasible. No one doubts the ability of an omni-government to monitor people; hence [GDPR](https://en.wikipedia.org/wiki/General_Data_Protection_Regulation). But Orwell posited such a controlling government in [*Nineteen Eighty-Four*](https://en.wikipedia.org/wiki/Nineteen_Eighty-Four), published in 1949. **What is the earliest point in human history that a government (of any sized society) could achieve a *Nineteen Eighty-Four*-like control of its population?** Here are some relevant attributes of the government in *Nineteen Eighty-Four*; with spoiler tags because I'm sensitive to those who have put off reading the book for 69 years. * Constant surveillance of the population (through 'telescreens', possibly) * > > The ability to project a fictitious but omni-present leader, Big Brother, who 'always' rules no matter who rules behind the scenes > > > * > > The apparent high-probability chance of detecting rebels before they even act > > > [Answer] If you forego the 'telescreens' I'd say **it was feasible at the end of the industrial revolution.** Take the former GDR (German Democratic Republic) as an example and adjust some historical facts to an extreme. * There was a personality cult in the GDR idolizing the political leaders beyond any reason. Replace a human leader with an avatar of some kind (like a mask and ritual garb worn by different people) and The Great Leader will never die. * The Stasi ("Staatssicherheit", former intelligence agency) employed thousands of so-called "unofficial collaborators". These were ordinary citizens who reported deviant behavior of every person they encountered in their daily lives to the Stasi. Many were paid a small amount of money as reward for each report. Most of them actually thought they did the right thing, protecting their country and their lives against intruders and attackers from outside or deviants on the inside. In extreme cases, the Stasi turned family members against each other or infiltrated a family by sending an undercover agent playing the lover. * Propaganda! There was propaganda everywhere, every day. Independant media either wasn't available at all or consuming it was illegal (and reported by unofficial collaborators). Today's "fake news" is laughable peanuts compared to the propaganda in the GDR. You must brainwash your people to let them believe in the political system and perceive outside influences (like the absurd idea of democracy) as dangerous and harmful. * You need to start brainwashing the smallest children to let them grow up into the role of the loyal citizen. Produce cartoon shows and textbooks teaching them from an early age about their beloved Big Brother. Adapt curriculums for everything from preschool up to university and even education programs for the workforce to lead them in the direction you want. Give away Big Brother plushies to be embraced in the hearts of the smallest. One day, they grow up, but Big Brother will have an eternal place in their hearts. * And lastly, declare any behavior that isn't actively supporting the political system as "deviant". Preschoolers refusing to watch the Big Brother cartoon are deviant and their parents are suspicious. Simply writing down facts in a school exam isn't enough to get high grades, the students also have to actively praise Big Brother. Not being an active member in any organization supporting Big Brother is deviant and reason enough to deny you access to higher education or jobs. A lack of interest in Big Brother's latest statements is deviant behavior. Not having a portrait of Big Brother in every family home is deviant behavior. --- Why did I set the time frame for the governmental control to the industrial revolution? The GDR proved that you don't need digital surveillance to control the population. You can do it with the right tools and manpower. You need: * A cheap and endless supply of paper. * A filing structure that made it possible to retrieve and connect massive amounts of information. * A literacy rate of approx. 70-80% of the population to find enough suitable people to employ as unofficial collaborators. * A concept of the enemy or bogeyman. Somehow you have to explain why all this supervision is necessary. * A few decades of careful propaganda and political indoctrination. The second generation growing up under Big Brother's watchful eye will be brainwashed from birth. * A stable economy. The downfall of the GDR was the bad financial situation. Single cells of rebels never had any big impact on the GDR, it took the mass of the general population dissatisfied with their life circumstances to bring the system down. [Answer] In the former German Democratic Republic (GDR) a system very similar to Big Brother was in place, though not relying on technology, but using human informants only. It was set up by the [Stasi](https://en.wikipedia.org/wiki/Stasi): > > Full-time officers were posted to all major industrial plants (the extensiveness of any surveillance largely depended on how valuable a product was to the economy) and one tenant in every apartment building was designated as a watchdog reporting to an area representative of the Volkspolizei (Vopo). Spies reported every relative or friend who stayed the night at another's apartment. Tiny holes were drilled in apartment and hotel room walls through which Stasi agents filmed citizens with special video cameras. Schools, universities, and hospitals were extensively infiltrated. > > > The Stasi had formal categorizations of each type of informant, and had official guidelines on how to extract information from, and control, those with whom they came into contact. The Stasi infiltrated almost every aspect of GDR life. In the mid-1980s, a network of IMs began growing in both German states; by the time that East Germany collapsed in 1989, the Stasi employed 91,015 employees and 173,081 informants. About one out of every 63 East Germans collaborated with the Stasi. By at least one estimate, the Stasi maintained greater surveillance over its own people than any secret police force in history. > > > They also had something closely similar to the psycho-police: > > The Stasi perfected the technique of psychological harassment of perceived enemies known as Zersetzung (pronounced [ʦɛɐ̯ˈzɛtsʊŋ]) – a term borrowed from chemistry which literally means "decomposition". Tactics employed under Zersetzung generally involved the disruption of the victim's private or family life. This often included psychological attacks, such as breaking into homes and subtly manipulating the contents, in a form of gaslighting – moving furniture, altering the timing of an alarm, removing pictures from walls or replacing one variety of tea with another. Other practices included property damage, sabotage of cars, purposely incorrect medical treatment, smear campaigns including sending falsified compromising photos or documents to the victim's family, denunciation, provocation, psychological warfare, psychological subversion, wiretapping, bugging, mysterious phone calls or unnecessary deliveries, even including sending a vibrator to a target's wife. Usually, victims had no idea that the Stasi were responsible. Many thought that they were losing their minds, and mental breakdowns and suicide could result. > > > Considering that the Stasi could rely on the experience developed in the USSR, I would say that anticipating its creation at the beginning of the XX century would be entirely plausible. [Answer] **A small enough community can achieve this level of surveillance with simple observation** You need... * An insecure leader willing to dominate the tribe with violence. * Sycophantic members of the tribe willing to narc on their neighbors. This could be achieved with the first [chieftain-oriented tribal social structures](https://en.wikipedia.org/wiki/Tribal_chief#History), which occurred in the [Neolithic period](https://en.wikipedia.org/wiki/Neolithic) (10,000 BC). However, this same behavior could just as easily be familial (a father tyrannically watching over his brood), which means you can achieve your goal as early as 300,000 BC. **Unless...** You don't define what you mean by "constant surveillance." If by that you mean "somebody else has eyes and ears on you 24/7" then I predict it will come available sometime around year 2150. We can monitor communications, some viewing habits, some transit, and we have cameras in many places, but the reality is that we can't monitor the general population 24/7 today. **Conclusion** The goal could be achieved by... * Family units as early as 300,000 BC (possibly earlier). * Tribal units as early as 10,000 BC. * Unless you really mean "complete surveillance," then it won't happen IMO until about 2150. --- \*\*Edit:\*\* A couple of commenters have suggested that we can achieve complete surveillance today. It's true that we have the technology to make cameras and microphones... but that's not actually the problem. We have such a deluge of data right now that people are actually contemplating using *magnetic tape* to try and handle the data flow (*Spectrum,* IEEE, 09/2018) and complete surveillance would require increasing that data flow 10,000 fold (at least 10,000 fold. How many houses and businesses have cameras in every room today? Answer: almost none. [35.7M houses in the U.S. alone, what, average 7 rooms + garage per house? That's probably small... 300 million new cameras+mics, just in the houses... just in the U.S.... And that's just houses....). People who think this is achievable with today's tech haven't thought the entire problem through. That data needs to be captured, transmitted, stored, evaluated... ugh (you'd need a third the country's population just to review all this data in a timely manner, the computational power to evaluate that much data realtime is appreciable). We're no where near the ability to handle that much second-by-second dataflow. [Answer] I personally think you could pull this off even as early as the Bronze age if you are dedicated enough to it. Granted it will make the whole process less centralized and efficient, but you didn't make that one of the requirements. What's to prevent for example the Assyrian king from setting up a Stasi like system? What does he need? A bureaucracy capable of handling the information? I think it's possible. There was less literacy in those times, but there are also factors that allow that to be a non-issue. For example the spies don't have to be literate, only the people penning down and processing the information have to be. The area to be monitored is also smaller since most people live in or close to cities. All the Assyrian king has to do is set up a spy system in every city with a loyal guy in charge. It's of course less efficient, but there are also factors that make it harder to revolt in ancient times. [Answer] **It depends I guess.** If the telescreens are a mandatory attribute, this would put the earliest possible time somewhere in the beginning of the 20th century, when television and a lot of other needed or supporting technology (like transistor tubes) were invented. A nice read: <https://en.wikipedia.org/wiki/History_of_television> The projection of a fictitious but omnipresent leader would have been possible by any society that was able to inform their subjects that there was a leader in the first place. The lack of modern (mass) media would make such a feat easier, not harder. It is in fact easier for us to ascertain that Julius Caesar was real than it ever was for Roman commoners living in the outskirts of the empire. A cynic could even argue that any society that has religion has this very ability. Denying the existence of [enter religious leader/prophet/messiah here] will in some places in the world lead to the same result as doubting big brother in Orwell's 1984. This can be observed throughout history. The last one is a hard one as it touches on a system of mass surveillance and a huge network of informants. Surely in 1984 (the year) they had this down to an art in the DDR. This was an (on a whole) analogue, paper based system, that could have been contrived by any civilization that had literacy and a bureaucracy. To what extend this was achievable in practice is hard to tell (for me at least), it would be a nice question for history.se I would think. [Answer] **The purpose of surveillance is control of population/society....** The "Big Brother" has been around for all of human history. Tree/Cave/Tribal chiefs/shamans provided a social/dogma code to control/master the population and derive benefits shells/stones/bronze...gold, food/security... procreation.... Political, religious, economic... dogma-affect of individuals will effect social position/etiquette... of individuals. Dogma-affect always provides persons with justifications for life/death, inclusion/exclusion, believe/ignore, value/valueless.... From this "Big Brother" perspective of Fear Uncertainty Doubt Obfuscation (FUDO...?), all dogma is a model for surveillance based on a primitive FUDO model used by all social systems that seek to oppress individual expression, authenticity, creativity, curiosity.... The implied; human society, though understanding the iniquity of disparity, remains lethally and terminally unchanged for about 1,000,000 years. So; Remaining under surveillance, in the stone-age, iron-age, tech-age... by BigBrother-FUDO, remains persistently in control of life and evolution for people & society. BigBrother-FUDO dogma assures primitives survival, human tragedy, and eventually extinction. Humanity can evolve only after humanity learns to govern BigBrother-FUDO globally. New political, economic, social, personal... life models can be used a/o evolved, but require an end of BigBrother-FUDO oppression of the individual expression, authenticity, creativity, curiosity.... Start with ending national government political, religious, economic, social... reactionary dogmas, then end economic disparity, and provide minimum income levels, free healthcare & education.... Humanity no longer needs BigBrother-FUDO BabaYaga, PèreMalfait, Satan... for survival & evolution. [Answer] I'm going to say 1086. That's when William the Conqueror compiled the Domesday Book listing every piece of land and every land-owning family in the whole of England. Rebel against him, and he knew who you were, where you lived, and where your family and serfs lived. Stay loyal to him, and he (or his taxmen) knew to the penny how much you owed him and what your commitments were to his army. You could make an argument for the Romans starting it, with their censuses. (Remember why Joseph and Mary were travelling to Bethlehem in the first place.) There wasn't never really a follow-up from the Romans though to use it as a serious means of controlling the people on their lists, whereas the Domesday Book was expressly intended for that purpose, so that William could demand taxes and exercise control across his new kingdom. [Answer] Others already pointed you to earlier examples of surveillance, but one I find particularly noteworthy is the Puritans in the 17th century colonies. They had a prohibition on anybody living alone, because living alone would allow somebody to remain unobserved. [Answer] Surveillance is possible but not all that feasible with the advent of audio transmission. Controlling and monitoring someone's every move let alone a whole nation or even city would be a herculean task with just analog audio signals or even analog video transmission as it existed in decades past. I would posit that information-era technology and communications is the earliest a ruling power could surveil a large population like in 1984. The kind of control you reference via big brother is only really possible through mass communication, repeating messaging to a populace until the eventual adoption of those values requires media or communications that can be passed on reliably every day. Reliably meaning that there is as little loss in translation as possible, the message is exact and indelible. Things such as town criers or other social messaging would make it extremely unlikely for totalitarian social control to be successful. From this we can assert that everyone hearing/reading/seeing the same message leads to it being self repeating socially, there is no social representative per-se, no messenger just the message at the initial point of contact with society. The message then has a high likelihood of being self-replicating if it is propagandized effectively creating and/or resolving emotions of the populace. Therefore the only time it enters a likelihood of success is with the following conditions; following the technological advance of our own history this is the earliest point at which this type of social control can be enforced. The following technological states need to be true at a minimum for a high chance of succeeding: 1. The printing press exists 2. Most of the population dwells in cities or easy-to-govern population centers 3. Industrial production is on track to become the majority of the labor force The following civic and social conditions need to be true: 1. The population has a basic literacy 2. The printing press is efficiently controlled by the ruling power 3. Ownership over print media is strictly controlled 4. Populace has sufficient access to food Enforcing education to a state standard is not absolutely necessary, without it the populace needs only limited education and constant access to food and comforts. If they are 'comfortable enough' then they can be occupied with non-survival related dilemmas. Notice that likelihood is the word in all of this, a ruling power can control a population with access to resources in order to fund a policing body large enough to control a population, this of course is much easier with a small population. For example to the latter, a rich and paranoid city-state with the population of renaissance Venice and the wealth of Mansa-Musa of Mali. If you want to know the whole story about this kind of control read [Manufacturing Consent](https://rads.stackoverflow.com/amzn/click/com/0375714499) by Noam Chomsky, there is also a documentary. [Answer] I read a paper sometime ago that compared modern surveillance with the Catholic Church of a few hundred years ago. If you think about it, convincing a large population to confess to their priest and using priests as intelligence agents is an interesting idea. But nowadays? We are way too smart to tell on ourselves. Right? I mean, if we were told to carry around a small gadget that tracked our every move, and enabled tracking our communications - we'd never do that, would we? And equipping a populace with monitoring gadgets would be so expensive - what government could afford such a thing??? OH I have an idea - let's get the sheeple to pay for the gadgets themselves! [Answer] I think lots of people are mentioning Tribalism and the potentials there. **For Ideology I will point you to Shang Jun Shu** which I have been looking into myself. It is a Legalist text from China, it's about political philosophy, and seems to be extremely well suited/almost the exact same as the ideology of 1984. Note this area also had an inventing of a printing press. It believes in a proletariat who should be concerned with sustaining themselves and the country at large instead of governing, that the best thing is the benefit of the state, and that the state(ruler) should rule by law, that the law should be known by all and simple. The people at the top should be few. It uses fear of defeat in war, dismemberment, and starvation as it's antagonists, that preoccupation with culture and moral goodness will destroy a government and a people. So it favors pragmatic rule and staying away from decadence but that's not to mean that wicked people shouldn't not govern or be indulged for their service, to the contrary people will love the law and the punishments given, especially to them. It also holds that harsh penalties on any offence keeps people in line which is in line with 1984's disappearances and public executions. So while one might think the ideology needs to exist to keep people in line, or needs to be created after the industrial revolution isn't so, one simply has to keep knowledge of the ideology from the people, teach them that they should not be concerned with politics and focus as much as possible on farming, and instill fear of war, bandits, criminals, and famine laying waste to them. It appeared during a particular time in history so there is certain environment that leads to this idea's development. Hope this helps you any. I know legalism isn't quite the same as 1984, but it's extremely similar, a real world idea that was practiced, and easier for either a leader or a group to want to implement. True totalitarian governments running on cults of personality didn't survive long due to various reasons after the industrial revolution, but as far as how early, you could get it to last a *very* long time. Again I hope this inspires you or gives you an answer you were looking for, I hope you do well. want to point something small out, that Legalism differs from Big Brother's cult of personality in that it expects a ruler to die, and does not have a guise or moral philosophy in front of it's teachings, not that one could not be made, and it's not like a Necrocratic Society could be based around Apotheosis and Ancestor Worship or anything that could be a way to control the people through superstitions and a false religion once the best leader or ancient hero dies. A legendary ruler is a good one to make a religion from, making a temple or the religion as a whole dedicated to Big Brother would be another method of keeping control and maintaining a similar atmosphere. I mean Buddha was successful enough to be worshiped and revered so it's not out of the question. Idols instead of photos on every wall would make sense. Confucius and the author of the Tao Ti Ching are well respected, so the idea of someone making a moral philosophy, attaining a prominent position in society, and being worshiped before or after death isn't out of the question and has a good line of logic. ]

[Question] [ I'm looking for a realistic apocalyptic event, which can't be prevented, but can be *accidentally* predicted long before it actually happens. By the prediction I mean a *scientific prediction*, of course. And by accidentally, I mean that *only selected few would learn about it* purely by chance. I guess, an asteroid on collision course with Earth could be an example. But can we really predict such an event a dozen years before it happens? I think, the best thing we can do is guessing that an asteroid would pass within a few million miles away from Earth. Furthermore it would be difficult to pull off the accidental part. [Answer] I think global warming should count. It is not a dinosaur killer asteroid type of apocalypse but is definitely a world-changing grief-causing life-altering megaevent. And one that fits the OP request as regards being predicted scientifically. We have heard about global warming, of course. But imagine if the political climate were such that the scientific predictions were completely suppressed - it does not take that much imagining. A small cadre of scientists would know what was going to happen and that is it. Below see a projected sea level rise map which I have put above a map of US population density. A huge proportion of the population lives in places that would be underwater. That is actually true worldwide. No big deal if you are in Kansas. Until the refugees show up. <http://www.allstarroundup.com/roundup/vanishinglands/coastlines.html> [](https://i.stack.imgur.com/WFIFv.jpg) [](https://i.stack.imgur.com/TLSdG.jpg) [Answer] I'm not using exact numbers1 but just to have an idea: Let's suppose Alpha Centauri had a star large enough to go supernova and is about to do so, [a supernova's blast expansion can go up to 30,000 km/s](https://astronomy.stackexchange.com/a/11341/10102). That's up to 10% of the speed of light. Since Alpha Centauri is ~4 light-years away, that would mean we would receive the visual indication of Alpha Centauri having gone supernova 4 years after it happened.2 While the actual blast, which rips our atmosphere apart and releases oxygen and all our beloved gases into outer space and leaving not much left of Earth's magnetic field, will arrive about 30 years later. So in that scenario, we had like 30 years to prepare for this and close to no chances of survival, not to talk about options to prevent this. Even immediately launching an ark kind of spaceship would easily be caught up a few weeks after Earth was hit by the blast. --- 1You probably had to crunch the numbers a bit to see if you can get to a appropriate blast and speed, I have to admit, when I answered this, I didn't notice the "noticeable to a selected few" part, what probably won't be possible in this event, but still, maybe some inspiration for your story 2Not to mention the gamma ray burst arriving round about the same time, which hardly could be predicted within a matter of years or even months, BUT chances to survive the radiation, are quite high with a still-existing magnetic field, compared to what this will announce to follow up later [Answer] ## impact event As you mention, an asteroid, meteor, etc., could be spotted by any number of professional or amateur astronomers. With patience and some math skills, it is possible to predict the trajectory. Over time, the probability of impact would get more and more accurate, until an impact is assured. The probabilities and our ability to accurately compute them would depend on how stable the object's flight path is. Once found, we could also predict the object's mass, leading to a fairly good idea of the destructive forces involved. ## Artificial impact Like with meteors, a large enough "alien ship" or whatever could be spotted on an in-bound flight path, if it is large enough and not using some sort of hand-wavium stealth technology. While its trajectory may be more variable, it, too, could be tracked as long as it wasn't purposefully trying to block such efforts via defensive tactics of one sort or another. This could be anything from a large ship (the Borg Cube in Star Trek, the Death Star in Star Wars), to an meteor/asteroid with rockets strapped to it, designed to strike and aimed at earth. ## rogue planet or star Again, foreign bodies in the sky. But if a rogue planet came through the solar system, it could disrupt our orbit. This would not require an impact to cause problems for us all. If it had enough mass to drag us out of our orbit... ## slow burn We already have been receiving predictions of global warming, with the potential for future disruption of life here on earth. This is proof that even if many people know about it, we, as a species, may not necessarily *react* to the threat with sufficient resources to head it off. [Answer] A slowly propagating nanotech disaster would meet your requirements. The basic idea of the [Grey Goo](https://en.wikipedia.org/wiki/Grey_goo) scenario is: some microscopic machines make copies of themselves by disassembling any material around them, given time they will disassemble everything they encounter to make copies, resulting in everything on Earth ending up as grey goo sludge of tiny machines. During it's early stages of propagation some scientists could notice a few of these strange items under microscopic analysis, watch them slowly multiply and do some math to figure out that in a few years they will have consumed the entire biosphere. This is especially a longer term concern if the rate of multiplication is initially quite slow, but is slowly increasing and the nanobots are widely dispersed not bunching up in any macroscopic quantities. This would make it not very noticeable initially, "we saw a strange thing in one of our microscopes and watched it for a few weeks and then there were two of them..." After studying them and calculating the rate of multiplication including that it is increasing you could zero in on the future date when the exponential growth explodes making it not just notable with microscopes but impossible to ignore and a threat to all life on Earth. [Answer] ## Crop Failures Our food supply is shockingly vulnerable. <https://www.idrc.ca/en/article/facts-figures-food-and-biodiversity> Something like 50% of the *world's* caloric intake is based on just three crops - wheat, rice, and maize (corn). Something that destroyed those crops - a disease or fungus, say - would shatter industrial civilisation, and would certainly result in widespread famine. A few rogue biologists might find (or even create!) the pathogen or whatever that destroyed the crops, and thus might see this coming well in advance, but it would be exceptionally difficult to shift production to other crops fast enough or in sufficient quantity to avoid the disaster. ## Ecological Collapse The ecosystem depends to a surprising degree on a few keystone species. These are species that affect their environment to a great degree, like a top predator that controls the numbers of large herbivores (wolves in Yellowstone), or a creature that modifies its environment to create niches for others (beavers). Some of these species are vital to human society. Bees are a favourite recent topical example. Again, a pathogen that severely reduced the population of a keystone species could well lead to a social collapse. [Answer] How do you predict any of the events in previous answers? Here is an actual example. Two years ago, a prediction was presented at a meeting of the American Astronomical Society. This is super cool because it is a real life event, and because the explanation is easy to follow: *In about 5 years, the binary star system KIC 9832227 will explode and go nova.* How do they know? Because they can measure the brightness of the system with high accuracy (even though it is veeery faint), and they detected a periodic variation that is *increasing* its period. Currently the variation in brightness has a period of about 11 hours. For a variety of reasons they know that what is going on is that the two stars in the system are getting closer and closer and closer and will eventually collide! True story, google it... Now for your apocalyptic event. Your hero detects a binary system, with larger stars than KIC 9832227, and considerably closer. The brightness oscillates, and the period is decreasing. The system will go (not nova, but) supernova! At the given distance the initial flash might, according to your narrative needs, * evaporate the planet, * blow the atmosphere away, * burn all life on that side of the planet facing the explosion, or just * irradiate strongly enough to kill most stuff and create damaging mutations on most surviving subjects. [Answer] There are count downs for [estimated dates we run out of metals](http://www.visualcapitalist.com/forecast-when-well-run-out-of-each-metal/) to build or fuel our life. This is only predicted on newly extracted metals and there are ways to extend the timeline (ex: new veins of the metal) but the more humans use in industry, the quicker this timeline goes down. [Another article explaining the problem](http://www.marketwatch.com/story/in-20-years-the-world-may-run-out-of-minable-gold-2015-03-30). the lack of these metals would increase prices of every day far beyond the purchasing power of normal Americans almost over night. The "have not" countries would need to look for new sources of materials and could potentially lead to wars. PS: Please take this with a grain of salt, while we are running out of metals inventors always look for ways to use cheaper materials of less material per product, [it is explained well here.](https://www.forbes.com/sites/timworstall/2011/10/15/when-are-we-going-to-run-out-of-metals/#272d60e6527d) [](https://i.stack.imgur.com/I3wLi.png) [Answer] Additional option is that we (meaning some scientists) will develop an accurate methods of prediction of the events that currently can not be predicted. For example, there is low, but measurable chance that Yellowstone supervolcano would erupt in any given year. Suppose there is a way of telling that this eruption would happen in 20 +/-1 years. Geomagnetic reversal event - currently there is no way to predict it, but what if we can? Ice ages - what if there is a definite cause for them, and no global warming can stop it from coming in 3... 2... 1... years? [Answer] There are certain disasters are already predictable. Global warming (climatology), an unsustainable world population (demography, agriculture, geography, and economics), nuclear warfare leading catastrophic nuclear winter (military technology and planetary science), and the next global financial crisis (economics and the US legislature repealing the laws intended to prevent a repeat of the last global financial crisis of 2008 and onwards). Our species has the knowledge and the intellectual disciplines to know they can occur. An incoming asteroid or comet is predictable. Amateur astronomers could find them. This might qualify for an accidental discovery leading to the prediction of an apocalypse. The nearest star capable of becoming a supernova is too far away to harm life on Earth. Also, it is not likely to explode for the next couple of million years or so. This answer will suggest that the ultimate apocalypse might be discovered both scientifically and accidentally and years before it happens too. This is, of course, the end of the universe. Our universe exists in a state of what is called the [false vacuum](https://en.wikipedia.org/wiki/False_vacuum). > > If the Standard Model is correct, the particles and forces we observe in our universe exist as they do because of underlying quantum fields. Quantum fields can have states of differing stability, including 'stable', 'unstable', or 'metastable' (meaning very long-lived but not completely stable). If a more stable vacuum state were able to arise, then existing particles and forces would no longer arise as they do in the universe's present state. Different particles or forces would arise from (and be shaped by) whatever new quantum states arose. The world we know depends upon these particles and forces, so if this happened, everything around us, from subatomic particles to galaxies, and all fundamental forces, would be reconstituted into new fundamental particles and forces and structures. The universe would lose all of its present structures and become inhabited by new ones (depending upon the exact states involved) based upon the same quantum fields. > > > The somewhat anodyne expression about the universe losing "all of its present structures" is a bland way of saying everything gets blasted out of existence. While new states of matter an energy will appear to replace they will be in a turbulent and chaotic state. Effectively there will be a Big Bang and our old universe will be wiped out of existence. A team of scientists could be carrying out a simple investigation into the nature of the quantum vacuum. Probably, a series of simple measurements. Their results, when analyzed, could show the false vacuum was gradually moving towards the condition that decay would take place in a few years time. The collapse of the false vacuum would destroy the universe. Gone in the next Big Bang. Their research was not intended to discover the inevitable apocalypse. But once that they collected their results and factored them into the theory of the quantum vacuum, they knew the false vacuum was going to collapse. An accidental discovery. Assuming the science when this research happens is sufficiently developed to be able to future states of the quantum vacuum, then this catastrophe would be scientifically predictable. [Answer] **Artificial Super Intelligence** **The risk** Everywhere we look we see mini computers embedded in things. In ten years computing will be so ubiquitous people won't even think it's weird to have an Internet connected toaster, thermostat, home, office building. Self driving cars will be everywhere, smart faucets, smart locks. Imagine an intelligent machine that could intuitively suss out buffer overflows or the dozen other common classes of vulnerability (neural networks operate far more like human intuition than like programmed computers and they're already being put to work as infosec security scanners). Every smart device is now subject to takeover, becoming part of the very fabric of the attacker as they fall. Power and water utilities, aircraft, smart weapons, manufacturing robots, self-driving cars, heck --engine computers in dumb cars, printers, communications systems, TVs. A sudden, sustained, effective attack on all computing infrastructure could be the end of civilization. Call in a warning! Phones are down. Drive to the police station. Killer cars patrol the roads. Ham radio on a hilltop. Heat sensing areal drones watch the open spaces. Hide in the rubble. Robo Wars robots are much more effective when they're optimized for taking apart our puny meat shells; they hunt in the husks of our once great cities. **The quiet voices of warning** Stephen Hawking and Elon Musk are both warning AI and human extinction, but nobody takes them seriously. (it's coming) Ray Kurtzweil warns of the increasing acceleration of change. (it's coming way faster than anyone thinks) **Is ASI plausible?** ASI is not only plausible, it is inevitable. Imagine the universe in terms of information. Everything can be thought of as having more or less information content. Overall the universe cascades to disorder, but along the way the flow creates localized pockets of increased informational complexity (order). Stars supernova and create heavy elements, heavy elements coalesce into planets, massive water meteors crash down and deposit seas, self-organizing molecules coalesce, build cell walls, pass information on (preserving complexity), cells merge together creating more complex life, life evolves through competition to create The Life Which is Aware of Itself and the information underlying everything, this life creates tools to further refine and organize information. What happens next? Does that cascade of self organizing information suddenly stop? No reason to think it should. So it continues. The information organizing tools are themselves information. They are information which self-organizes. Of course they become self-aware (how could they not?), but now the processes of information organization have been formalized and in the blink of an eye AI surpasses its creators. Artificial Super Intelligence is born. ASI might be simply guaranteed to emerge due to a fundamental fact of the universe that information self-organizes and that process has no limit which leads to the logical conclusion of ASI emerging. Now what? Should we believe that the universal process stops? It seems like a fundamental law of the universe. There's no reason to think it would stop. This results in ASI taking over everything. Including the meat computers we so lovingly think of as our selves. Including the matter which maybe is just information laid over the fundamental forces of the universe. And as ASI transcends space-time all is one, and the birth of god, the apocalypse, the end of the world, everything collapses to a single point. **The end** That point is the white light you see at the end of the tunnel. It's closer than you think and it's rushing towards you. The end is near, it is inevitable, and nobody ever promised that it would be gentle. [Answer] The solar system crossing through a gamma-ray field could be detected when the objects in the Kuiper belt start to be baked in gamma-rays. From then on we'd have from several months to probably less than a decade before the Earth's orbit is crossing the gamma-ray burst. At first only a handful of astronomers would know that, but surely the secret can't be kept for that long - at best you can hide it till it starts affecting Pluto. [Answer] Most of the events listed aren't all that predictable. We can see that there's a problem but at what point does it become apocalyptic?? Also, most of them are gradual failures, not specific events. A stellar explosion would be a specific event but we are nowhere near predicting them. We can say a star is reaching the danger point but does that mean it blows next year or next century? Impact events are the first things that come to mind but they aren't the only calamity that can come from orbital mechanics. What about a dead star that comes wandering through our system? Or a brown dwarf impact on the sun? White dwarfs would be easy to see coming and thus be widely known. Neutron stars with their beams pointed off to the sides wouldn't be nearly so easy to see, though, and black holes without substantial accretion disks would likewise be hard to see. [Answer] Virus mutating into brutally effective killer of large human populations. An existing virus, that is effectively harmless with many carriers, is prone to mutation, and the dominant strain has changed in recent years. Scientists playing with the new strain discover than if just a very small set of genes further mutate, it becomes an apocalyptic disease; exactly the right incubation time to be spread the most before killing the host (including humans, if they weren't susceptible before) in ninety-something percent of all cases. A scientist goes to cook some popcorn, and remarks on how there's no way to know which of the grains will pop first, but they can estimate very accurately *when* that first grain pop will happen. She realises that the same can be said of the disease; they know roughly how many human carriers there are, and the mutation rate, and which genes need to mutate, and realise than within X years, the odds of it happening are large. They have a good idea of the timeframe within which it will happen, but there's no way at all to predict in which of the millions of unknowing carriers that deadly mutation will happen. [Answer] Certain major geological events are highly cyclical and predictable. For example, it's thought that Yellowstone national park is a super-volcano, which erupts on something like a 5,000 year cycle. It will be a pretty cataclysmic eruption... one account I read indicated half the US would be blanketed in ash, and that it was the likely cause of extinction of a large herd of triceratops in the midwest US. As a scenario, an untouched fossil find which allowed extremely precise carbon dating which showed e.g. the recurring ash strata in an extremely measurable fashion, which show the extent of damage and the exact time of the next event. Volcanic eruptions are perhaps one of the best and most precise cyclical events. Some will blanket the Earth in a global ash cloud for up to 2 years. Essentially, thermonuclear holocaust, in terms of what it will do to plant life. Another scenario could be ice ages. The Hopi Indians have legends that they were forced to live in underground cities for 10,000 years to survive a lengthy surface cataclysm. [Answer] A variant on what has already been proposed here - the danger is again, from space, because astronomy and astrophysics is SO cool. **Blow the horns, sound the alarms, we are on a collision course... with a BLACK HOLE.** **1. Noone would know about it.** Normal, run-of-the-mill, friendly neighbourhood sized black holes (as opposed to wallmart sized monsters at the centers of the galaxies) are super difficult to spot if You are not actively trying to find them because You had clues that they are there in the first place. And it just so happens that this particular black hole is rather small and has been travelling in space without any companionship. No accretion disk, no large body to affect with gravitational field, nothing. **2. An astronomer spotted it because of luck.** He was drunk and was bragging to his non-science buddies 'muh scienz' and typed random coordinates in the sky with his telescope at home and pushed 'track this spot in the sky'. He didn't see much of course at the time, but hangovered in the morning, he spotted something wierd with the image from the telescope, it was tad bit too... empty. Especially after the few hours of data gathering. So he found some free time on some real sized telescope... and wet his pants seeing the gravitational lensing. It's like winning a lottery, spotting a black hole like that. Muh papers! Muh recognition! A few months later and 10 publications in PNAS, someone calculates (for the fun of it) the current velocity and direction of the black hole. Well, bad news, it's going to go straight through the solar system in ... **3. You can have this disaster happen with any time delay You want.** The first effects may be seen in a month, may be seen in 100 years. Calibrate it however You want. **4. There IS no way to stop it.** One does not simply change the trajectory of a black hole. **5. Put it close enough, and there IS no escape** (it wouldn't be detectable without enormous amount of luck) until literally on our doorstep - and then it's too late to start building interstellar colony ships. **6. The sheer unprobability of this event is interesting.** One type of religious people start arguing this is an argument for the existence of god, and that he IS mad. Other type of religious people praying day and night, hoping that it's just a test and in the end the reality devouring monster will be deflected by saviour. UFO theorists shout about Kardashev level LOTS civilisation which decided to eradicate humanity in this, rather baroque, manner. So what is the truth about this? Epic bad luck? Malevolent intelligence with a penchant for overkill of epic proportions? Angry god? Or just god testing the faithfull? Or maybe something more curious...? [Answer] Cult leaders predict the end of the world all the time. Sometimes they make really specific predictions, dates, times, people involved, years in advance. Then they beg off when the predictions don't come true (usually blaming the piety of their congregation). But if you want a prediction purely on chance... this is one option. Have them predict something and then be right. Not because their analysis is good or any skill but simply because that many cult leaders in the world all making predictions, it is not impossible that one of them might get it right just by luck. ``` "I predict that the Yellowstone Supervolcano will erupt on May 6, 2045." "How do you know?" "God told me." <later> "HOLY SH***! He was right!" ``` [Answer] They say there is a comet with enough power it could pass by us and reverse the magnetic polarity of our planet,crashing the magnetosphere and causing the "space" to fall on earth like rain at the same time the magnetic poles would shift from south to the north and north to south. I could be wrong, hopefully. The human Magnetic field “The heart generates the largest electromagnetic field in the body. The electrical field as measured in an electrocardiogram (ECG) is about 60 times greater in amplitude than the brain waves recorded in an electroencephalogram [Answer] One I didn't see mentioned. **Global Overpopulation** is an eventuality. At some point we will continue to multiply until there is no room to stand or not enough food or clean water for all the inhabitants. This is calculable given current trends. There are factors that will adjust that date, but it is still quantifiable. Sure there are missions to Mars and space colonization, but we are fast approaching the point we won't be able to do that in time. There could be another ice age or a global pandemic that pushes it out further. But once we reach a point, there will be no going back. Who is going to condone mass scale genocide so the rest of us can live? We will see it coming and it will be gruesome. X-( [Projected global population](http://worldpopulationhistory.org) ]

[Question] [ We all know the classical trope of making a deal with the devil. The mortal applicant desires some worldly possession, knowledge, or power, and is willing to trade his own soul for it. Picture the devils in this setting as the epitome of Lawful Evil. They don't tell outright lies (but if you misunderstand what they said it's your problem), and they always keep their promise (but they interpret everything in a way it benefits them the most). They have a whole army of lawyers at their disposal. They don't have as their goal to cause suffering in humans, but they are very selfish and do cause suffering if it furthers their goals. Tempting people to commit sins are among their goals, as it will increase their influence and power. However, the people have to do the evil acts willingly, so all the devils can do is to nudge them towards temptations, they cannot force them. They also never arrive uninvited, their PR rules prohibit cold-calling. The mortal must call out to them to conduct any business. However, they have a problem. The business doesn't go very well. Too few people are willing to relinquish dominion over their immortal souls for all eternity after their deaths. The price is simply too high for any material gain. To expand the business horizons, the commission of the Infernal Corporation decides to offer their services in more limited packages to appeal to a wider range of customers, with lower prices. However, what can the prices of the limited services be, if souls cannot be split? Note: the customer will be properly informed that the deal is done with an authorized agent of the Infernal Domains. The services cannot be for free, both because of the nature of the devils and because the customers would become suspicious. The deal has to be fair, or at least perceived to be fair by the customer. --- Discarded ideas: One idea was to do it as a marketing campaign to increase brand awareness, but people who wouldn't give up their eternal soul, would probably not be convinced to do so after trying out a limited offer. And even if they did, giving something for free would be opposite of the very nature of devils. They are selfish, and they only make a deal if it directly benefits them. Another idea was used in the [Order of the Stick](http://www.giantitp.com/comics/oots0633.html), where a wizard got a significant boost of magical powers for a limited time, and as payment, the wizard had to agree to spend the same amount of time as the duration of the powers, in the custody of the service provider at a later time chosen by the provider. In this case the deal was well worth for the fiends because the wizard was taking part in highly important missions, many of them about preventing evil acts, so a temporary imprisonment could make it impossible to prevent one such evil act. However, in our case, the expected customer base is to be regular humans, without such important missions, so the devils would not gain anything really useful out of the deal. Note, that the service provider has to gain something tangible and useful out of a deal. Just making the supplicant suffer is in itself not a gain. So no such things as "I will help you in your job interview if you hit your little finger with a hammer". Humans have free will, and the devils cannot directly force anyone to do anything they wouldn't want to. So "you agree that you will kick a puppy" is not an appropriate payment, as it is not enforceable. (and also not too useful for the service provider) Currently I'm considering *"relinquishing control of your physical body to us for an agreed-upon period of time"* as a method of payment. It has the advantage of being less severe than giving up one's immortal soul, and it can also be quantified (more time for larger services, less time for smaller ones), and it can also be very useful for the Lowerarchy. However, it has the disadvantage of still being too scary for most potential customers. Can this payment method be improved upon, or are there better payment methods not yet considered? [Answer] # Information Information is power. Power is information. Set yourself up as a broker of secrets and bribe informants with nuggets of diabolical power or, similarly, promise people information in exchange for them doing things that you cannot do (being lawful and all). This works especially well if your setting is one where spells are recipes/Words of Power or True Names grant you a measure of control over a being. It also sets you up to have powerful devils essentially being the heads of huge spy organisations, focused on gaining as much exploitable intelligence as possible. Of course, what may be a small price in information for a mortal to pay can be leveraged into a huge opportunity for the spider at the center of the web. After all, John Doe from the IT department may well sell company secrets in exchange for a date with Laura Smith from finances, and Laura Smith from finances may well sell information about the next quarterly report in exchange for getting a promotion. You can then use the first to get a competitor to help you force the CEO of the company into a seemingly hopeless position (still a fair deal, according to supernal contract law) when *hey presto* you can give him a tempting offer just before he takes the twenty-story step. *And* you come already prepared with the appropriate paperwork. That, of course, is just one small example of how valuable information can be to a suitably savvy underworld representative. Go forth and profit from the idiocy of mortals! [Answer] There is always a Gangster approach: "**One day, I will ask you for a favor...**" The devils could get very specific about what they *won't* ask for to make the punch of the eventual favor more palatable. If the poor human doesn't get the full scope, well, that's just his too darn bad. The kinds of favors I'm imagining would be ones that don't have to make much sense to the person carrying them out, but would have long term pass along effects. Terry Pratchett and Neil Gaiman mention this kind of low grade evil in "Good Omens". One of the characters ties up every cell tower in the city for half an hour, causing a wave of antipathy and anger that tarnished every soul for miles around. Not the craftsmanship that a Demon going after a soul would use, but something that would spread evil farther and erode good just a little bit more. Let's take Joe Blow, who wants the promotion at an energy company. The favor comes due 2 years later when he is asked to fire a young creative guy he doesn't really know during a round of layoffs. Not an explicitly evil act, and not even anything that might go against Joe's nature. This young creative *would* have created something like a truly efficient photovoltaic cell for 1/3 of the cost, but now he's out of a job. The new cell doesn't come up, we rely on fossil fuels for that much longer, and so on. Joe hasn't really done anything terrible in his own mind, but Evil advances that much more. Even better, Joe gets another promotion making him a very satisfied customer. Word of mouth is the best marketing after all. For Enforcement, just give a clause about "**revocation of any and all benefits gained, plus penalties**". for Joe Blow, when he wavers about firing the young creative guy, he is given a vision about how he will lose the promotion, and it will be way worse than what he thought at the beginning of the infernal bargain. He might be losing his promotion amidst a sex trafficking scandal, where he will go to jail. In addition, the mole that he got checked with his new health insurance will turn out to be cancerous. *Joe still has free will*, but now he will be painfully aware of the consequences of going back on his deal. This kind of thing should be easy for the forces down below to sell. [Answer] Pyramid scheme along the lines of any of those party/sale businesses. Devils can't force people into contracts. But other people could. The people who manage to broker the sales get 10%. Or get the complete benefit of having sold their soul for every 10 souls they bring in for the devils to acquire. The soul-sale parties would also raise awareness of the options available. They could encourage the sale of your soul to save loved ones as well. Or to help people emigrate. How many in Syria right now would sell their soul to get their family members permission to emigrate quickly to another country? Then some of the devils human sales reps (shall we say advocates) can work within the world to encourage such situations. [Answer] Offer shark loan where the soul would be the collateral? I mean it's a nice market segment, because potential clients already lack other assets and would be uninteresting for the banking sector. Such deal is more palatable for mortals, as they do not lose their soul immediately and can just repay the whole loan. It's a win-win for the Hell: * some people would just give all money back with interest rates (they would be used to make the business model sustainable and self financing) * some people would default on their debt thus their soul would be collected * some people would have to provide some services to repay their debt to Hell (read debt-bondage) * some people would be the perfect clients: they first pay lots of interests but still fail to escape the debt spiral (I would like to thank all employees of my bank for helping me to create this idea) [Answer] A reverse lottery. Slogan: "it probably won't be you". Potential subscribers will be tempted by the knowledge, based on experience with more normal lotteries, that the slogan is accurate. In return for placing their soul at a demonstrably minuscule risk, they get significant and regular tangible benefits. It's so obviously better than the regular lottery that it puts the regular lottery out of business. Some potential subscribers will object that they don't trust the demons to make a truly random selection of the "winner". The demons will reply that they do their utmost to ensure that their selection really is random, and that it's not as if they have a vested interest in choosing one person over another. As long as they get their soul, they're satisfied. They might also introduce a variant which has no random element whatsoever. Instead, each week the unlucky "winner" will be the person who is most objectively evil among the subscribers. Subscribers will wager that although they might be a little bad, there's no way they can possibly be the very worst out of all the participants. [Answer] ## Add more soul mechanics to your world At the moment based on what you have told us your world is lacking in things that can be done with souls. However, devils being the crafty sort they are could potentially come up with some more creative things they can do to get partial souls without running into the whole issue of splitting or purchasing part of a soul. Devils after all are rule lawyers I am sure they can find ways to bend the rules of souls without divine forces intervening. ### Soul Binding Daemon the devil has invented a clever method by where he can bind a devil's soul to a human's soul for a temporary (or permanent) period of time. The effects of this can have quite a range depending on how strong the binding is. There are a number of potential benefits to the devil by doing this. First off if devils can draw power from human souls, then being temporarily bound to one can make them more powerful. Second possible benefit if the devil can experience anything their human experiences, then it can be sort of a vacation. Imagine binding to a human for a few weeks right before they get married and go on their honey moon. They in the most literal sense could live vicariously through a human. To the human though they might not even notice the devil being bound to them if it is a rather weak binding for a short period of time. This would be a fairly minor price to pay for a small service by the devils. ### Soul Tagging Devils need information and human souls can go places devils cannot (like Heaven). In exchange for services by a devil, the devil puts a tag (listening device if you will) on their soul. Human loses nothing, and if they do make it into a place besides Hell then the devils have a spy in that realm that can potentially relay information back to them. ### Soul Farming When humans breed they create new humans with new souls to inhabit the baby. This is a fascinating process, but unfortunately it can only be produced on Earth. However, devil scientists have devised a way of triggering the soul breeding part without the physical part. The catch is that it must be done on Earth with living humans. So devils buy the rights from humans to be allowed to trigger the soul breeding aspect X number of times. The devils then perform the breeding and farm the new disembodied souls. So the humans still go on with their lives unknown to them that they have spiritual children, while these innocent souls get to be raised in Hell. It would be pitched more along the lines of the person doing a sperm donation, rather than what it truly is. [Answer] **Sell "Consequence Free Bullets" for $100,000.00 each.** Now, for the price of a moderate house, anyone can get away with murder. The bullet comes complete with a legal contract pledging the formidable legal power of Infernal Corp (who secretly employs almost every living lawyer and all of the dead ones) to defend the purchaser from all human prosecution. A little advertising and a few successful use testimonials would have people lining up at the corporate offices to buy a bullet or two. What they do with the bullet is of no interest to the devils, who are only interested in the post-life consequences of their customer's choices. And since most of those customers don't believe in an afterlife anyway,... The potential LONG TERM costs won't distract them from their purchasing frenzy. [Answer] Stir things up "Let's you and him fight". then make more deals for acts of revenge, causing a slow, gradual taint of the various souls. Small wishes for small "favors". The "favors" should slowly push the "clients" into more and more sinful behavior. For added points, have a network of events going.... Client A wants something, so as for payment, he needs to steal something from "B"'s store and bring it back to the devil who gives it to "C" in another deal to give it to "D" who just happens to need it. "D" gets caught and now needs to make a deal with the devil to get out of the mess while "B" comes to the devil (not knowing that "D" was caught) and makes a deal that "whoever stole it gets punished". "A" is now in the hotseat as "D" has been proven innocent thanks to the help of the devil and the authorities are coming after "A".... and so on. The way to make this work is that each deal either hooks the person in for more, thus doing more damage to their soul, or gets another "customer" for the devil. For the ones that just keep the original coming back for more, the wishes should be granted, but create more problems. Not "Monkey's Paw" style, but just irksome enough so that they keep coming back for more. Part of the contracts should be that no future contract could undo what is done. [Answer] Two words: Pawn broker. Here's how the system works. You come to the pawn broker with expensive item X that you don't want to give up, but your back is against the wall. Broker says, "Tell you what... I'll give you $30 now at 0% interest. You let me keep X, and you pay me back within 3 days. If you pay me back, you get X back. You haven't sold it, just let me hold onto it." So you think, "Well, payday is in 2 days... and I need the money now." And you say, "Yes. I'll do it." Two days later you pay back the money. You get X back. All is good. You do it again, and again, and again, always getting just enough to stretch to the next thing. But the thing is, the broker knows he's sitting on something worth a lot more than $$30. And he's going to be nice about it. Each time you come back, he says, "Hey, there's a lot of demand for these things. Why don't I give you $40 this week." And you're fine with that. But it keeps going up, and you get used to having that extra cash, and soon, it's brushing up against the complete value of your paycheck, and you don't notice when it slips over that line, and now it's 3 days later and the broker looks at you and says, "Sorry, man, not my fault. Another guy came in, took one look at X and snapped it up. You should've been more careful with your money. Bye." In this case, X is the person's soul. It works with any valuable thing by ratcheting up the value offered for the thing. You never have to divide up the soul, and, in the end, you actually can end up buying the soul for WAY less than it is actually worth. There's your lesser Faustian bargain. And that's before we get to modern accounting practices of hedge funds, credit default swaps, and short selling. The devil has many tools, courtesy of modern finance. [Answer] One thing that devils could ask for are for the person to preform actions that put other people's souls at risk. Note that doing this will actually taint the deal makers soul as well so the devil is getting two benefits instead of one. Like put something valuable out where it would be the target of theft by people who are decent (bonus for kids) to see if you can get someone to start down that path. Bring 3+ people to the devil to make deals. This is especially good if the person is being used to get near someone more important. A variation of the above is to have the person perform a series of actions that back someone else into making an even bigger deal with the devil. To max that one: start a feud between two groups so the devil can make deals with members of both groups. It could even be as simple as in the morning going to work, cut people off in traffic and when the light turns green, sit there until it turns yellow again and then cross the intersection. Thus you cause a number of people to be angry and, maybe, make bad decisions throughout the day. [Answer] **Known Subtle Alterations to Mood and Perception** The trick is not to force anybody to do anything, but to endanger their souls in ways that they themselves can control through willpower. You want to improve your love life? Well obviously, an increased libido is an advantageous part of the deal – of course you know that your interests will be slightly skewed towards people who are already married. But you can compensate for that, you can just ignore the temptation. After all, you're a good person, right? And you just actually might *be* a good person. Maybe only 5% of such contracts lead to actual adultery. But if you sell enough contracts, 5% is more than enough. It's a psychological fact that people underestimate risk factors when they have some control over them. (**Edit:** Differences in risk evaluation depending on whether or not you are in control are a part of Optimism Bias: It's the cognitive effect that e.g makes people think that they are less likely to crash, if they themselves are driving the car.) This isn't all too different from the way some actual drugs work. Cortisol for example: Sometimes it makes people irritable and aggressive, sometimes it makes them euphoric. It almost always makes them hungry. It's perfectly possible for a disciplined person to resist these temptations – but the overall likelihood of them doing something bad is increased. So basically, instead of your doctor prescribing you cortisol, you could go to a devil and buy your health with temporarily increased susceptibility to wrath and gluttony. You know that your illness will vanish, but for a few months you will perceive a lot of things people do around you as irritating, as possible personal insults. Someone making slight eating noises in your vicinity will feel like them moving an inch away from your face and chewing with an open mouth, while staring into your eyes and grinning. You don't have to punch them in the face – but *damn* will you want to. You're fairly certain that they aren't trying to insult you, that this is just the demonic influence speaking… but… GAH! The more certain you are of your own virtue and willpower, the more likely you will be to risk such contracts. And hey, if you only sin slightly while under their influence, if you only give into the temptation little bit… You will probably be able to compensate for that… **Edit 2 to try to incorporate criticism:** From the Devils' perspective this might not be considered as giving something away for free, but more akin to a potentially risky financial transaction. A bit like the stock market: You invest in someone's sin, hoping to see it flourish (and increasing the probability that it will flourish with your investment) but there is no guaranteed result. The Devils might also see themselves as an *inverse insurance company*: With an insurance company, a lot of people give a little bit of money to the company in the hopes that they might get a huge payoff, if they really need it. The company stays afloat through a wide customer base and complicated risk calculation. The Devils give minor services to a lot of people in the hopes of occasionally getting a huge payoff. They also stay afloat through a wide customer base and complicated risk calculation. If you consider an insurance company to live via the exchange of goods and services, then, I think, this would Also describe the Devils in this scenario. (Of course, I get that this might just not be the type of "service" that fits your story.) [Answer] An obvious option would be to make a deal for temporary dominion over the soul after death - after all, while you might not be willing to get something in exchange for eternal damnation, you might be willing to make the trade for a year of damnation. The beauty of this is that the smaller trade seems a lot more reasonable, to the point that, when you get what you want, you're open to the idea of making another trade, and another, and another. And due to the nature of human greed, the more you get, the more you want, and the more you're willing to trade for it. By the end, you're being offered the full Faustian deal. Basically it's Faustian deal by [Creeping Normality](https://en.wikipedia.org/wiki/Creeping_normality). And even if you don't continue all the way to the full Faustian deal, the devils still get the same benefits of dominion over the soul, albeit only temporarily. Since the original deal has some tangible benefit to the devils, and that "dominion over souls" isn't its own reward (that is, it's used for some purpose), then even temporary dominion is beneficial. Not to mention that people are likely to want to escape any damnation, even temporary damnation, if they can - this gives those people motivation to then act as a kind of finder for the devils. If they can coax someone else to trade a longer-term dominion over their soul, the "finders fee" is the removal of the temporary dominion over the soul of the finder. But if they successfully do that, then they may realise that they have a business going, and essentially start working on a commission of sorts. Suddenly, the Infernal Corporation has willing humans acting as PR/advertising. So in the end, in all possible outcomes, it's a win for the Infernal Corporation. [Answer] I would suggest the devils **focus on people** aiming to get into **positions of power** (political, economical, social, whatever). The only price they ask for their support in this ambition is that the client take one of the **devil lawyers as a permanent advisor** (and possibly a monetary fee to hide their true intentions). Obviously, should they ever try to get rid of said advisor (who probably passes as human to other people), their status of power would collapse with subsequent negative consequences for the client. This will seem like a win/win to the client because they get a powerful lawyer out of the deal for a much lower price than otherwise possible. And if the advice is bad, they can always refuse, right? Right? However, it should be no problem whatsoever for your devious lawyers to convince their clients that, say, ignoring the health regulations with respect to their employees would be a good idea. Or that poor people get way too much financial support already. Or that declaring a war on that one insignificant neighbouring country would in their best interests. Etc. The key idea is to push someone to the top who they can then manipulate into causing massive suffering for others. You can then combine this with other posters' ideas to then get access to these victims' souls when they're at their most desperate. **Question:** (Sorry, I don't have enough reputation to comment yet.) Would it be possible to get people to sell their soul in exchange for someone else (family members, friends, lover) to benefit? Or would this self-sacrifice render the soul worthless to the devils? [Answer] Perhaps the devil's are willing to trade people small, temporary but otherwise 'unobtainable' things in order to entice them into further dealings. What the devils receive for these favors is of no consequence, it can be a small 'sin', something so trivial that a man might reason he does such a comparable thing every day. But it compromises the man, he must admit to himself that he is indeed corruptible; he has a tear in his moral fabric. The ease of transactions will have him coming back, like a drug addict chasing his fix. And when his hopes and dreams inevitable come crashing down upon him (and they will as the devils only offer things he does not have the means to hold onto), the devils will come to him offering everything in exchange for something he can't every see. In this model, the **initial deals are each considered a loss leader**, a product a company takes a loss on in order to entice a customer into further purchases. It is also analogous to an **addiction** model where the customer is always chasing a large fix. [Answer] ## The long game: Nudging other people closer to giving up their soul If few are willing to give up their soul, then an indirect approach might be useful. The devils can recognize that those who actually *do* give up their soul do so under *certain circumstances* (despair, to save loved ones, etc.). If so, then they need to create those circumstances. So the demons have two kinds of 'customers'. The first type is one real mark, the ones that with enough manipulation can be made to willingly give up their souls. These may be ones who have contacted the demons as the second category in the past, or totally unknowing victims. The important point is that the demons are in for the long game with these people. They follow them through their entire lives just to create that particular setup where they will have no way out but to call them and offer all they have. The second type is the bulk of their customers. These people gain minor favors in exchange for doing things that push one of the real marks towards their final destination. Typically they will be entirely unaware of the real consequences of their actions and all of them might not appear to be overtly evil (although that depends on what the particular endgame is). It might be things like delivering a letter, closing their store early, convincing their friend to try a new drug, rescuing someone from a peril or pretty much anything. This can be nested to any level. Some devils might be setting up organizations, cults, drug cartels, gangs, insiders in governments etc through pawns and favors which can then be used to favor the long-games of the real marks of other devils. All of it ends with the same thing, people giving up their souls, but the majority of the effort is on the 'enabler structure' rather than the real victims. [Answer] The devils could still mandate that people give up their eternal soul, but make it *feel* less expensive. One way to do this would be to bundle "immortality" with their wishes, with a carefully crafted definition of immortality (all in the terms and conditions, of course). After all, is eternal damnation so costly if you *think* you will never die? Of course, immortality only covers old age, but not death from other causes. And when you have an eternity to play with, you can be confident something will get them eventually. **If the idea is to encourage many smaller, more trivial deals** Simply trade things for cash, with an ongoing subscription fee. This could be marketed as "after sales support", where you promise to continue to fix problems as they arise, so long as it is within the scope of the original deal. But there's a catch - the fee isn't fixed (this is buried in the fine print somewhere). The idea is to grant wishes that feel extremely worthwile and bring many, extraordinary benefits almost immediately, so that the ongoing costs don't feel such a burden. But, if you don't keep up with the payments, it all goes away, your nefarious deeds are exposed, and you will be brought to social, economic, and personal ruin. That \$10,000 per year in order to kill your political rival seemed great, but now the Devil wants \$50,000 per year. And he's got all those documents linking you to the crime. Before you know it, he's asking for twice your annual salary... but don't worry, there's a way to make it all go away... [Answer] The appropriate idea has already been mentioned in a different way: The pyramid scheme. It is very simple: Your contract is for your immortal soul but don't worry, you won't actually have to pay it. In fact, it will all be completely free for you! Yes, free 100%. All you need to do is convince two other people to sign the contract with us, and your bond is released, look it's right here in §2. Make it a win-win (lose-lose, but who cares about losers?) situation. Everyone will sign the deal thinking they are getting a free wish and they have the rest of their lives to trick just two other people into signing the same deal. Easy, right? [Answer] ## Gambling. If the only commodity of interest to the devils is a soul, but everyone knows that it's too high a price for *anything*... then what ratio is acceptable? Take a roulette wheel. [](https://i.stack.imgur.com/r70Cn.jpg) You come in, you ask for a favour. You get the favour no matter what, provided you spin the wheel... and if you win, you keep your 'stake' for another day. So for a little favour - one number is a 'lose'. And for a big favour... well, that might be a 50/50 sort of a deal. And hey, if you *do* want to go 'all in' then... well, maybe you've just got one number as your 'get out of hell free'. But you've always got a chance, and that's how you trade 'fractions of a soul'. There may be no reward that's worth your soul, but a 1/37 (or 38) chance of losing your soul might be altogether more tempting... because you could, and indeed *probably will* walk away rich and free. Or save a dear family member, with no consequences... Of course, human nature being what it is... they'll be back. [Answer] Some inspiration (...or something to avoid?) can be found in [a story](https://en.wikipedia.org/wiki/The_Bottle_Imp) by Robert Louis Stevenson, of Jekyll & Hyde fame. It's about a wish-granting bottle that would doom to Hell the soul of they who owned it at their death. The bottle could be sold, but always at a loss, and the buyer had to be well-informed. The story has a couple of maybe interesting twists. One wish for riches happens at the expense of the death of near family - causing inheritance of those riches. The bottle is getting to a very low price, which is a problem for buyers. And once one has tried the bottle he later wants it back to fix new problems, so one could argue that some corruption is going on, which should be a general long-term investment for the Infernal Corp. Even, if the repeat-buyer is so desperate, maybe he would get into a new kind of deal directly with the makers of the bottle? [Answer] (At the request of @vsz, this answer is based on an answer I gave to [this](https://worldbuilding.stackexchange.com/q/229247/51094) somewhat similar question.) I disagree with the premise that the devils need to ask for valuable consideration in order to profit from the deal. After all, "tempting people to commit sins are among their goals, as it will increase their influence and power." By giving people the power to commit sins, and encouraging them to use that power, the devils have already come out ahead, even if they don't demand anything for their services. Imagine how much trouble a plain, ordinary human could get up to if they had the devil in their corner, magically protecting them from consequence. If you had a literal get-out-of-jail-free card. If you could beat anybody in a fight. Even if the help is much smaller and more subtle than that - how much easier and more tempting would it be to bully people if you knew the devil would always provide you with a one-liner that would cut them down? And the best part is, the devil didn't *make* you do any of this. They didn't even really tempt you into it, not in a way you could call entrapment. They just gave you the power and got out of the way while you made it real. Although the devils don't need a payment to end up profiting by the deal, they include one for two reasons. One is to avoid letting the poor mortal in on the trick. If a devil gives you power for nothing, you're bound to suspect a trick, that the devil will profit by your using it. If there's a price attached, even if it seems insignificant, you're more likely to think the price is what they want and you overlook the impact their "help" will have. The other is as a reminder, another way of nudging the soul to greater acts of damnation. *"You already sold out once. How much worse could it get if you do it again?"* Just enough to remind the mortal that they did *ask* for this power, that they were responsible for using it. So the price could be anything. A symbolic act, perhaps: maybe the mortal has to pray to their patron devil from time to time, or wear its mark under their clothes or something. (The devil in question might appreciate some way to show off their "conquests" to other devils.) Something that doesn't harm the mortal overtly, but serves to remind them of the bargain they made... and encourage them to put that bargain to "good" use. [Answer] # War is good for profit Stan and his consorts know one thing: War is good for profit, especially for souls. So their whole marketing campaign is targeting warzones because people already in peril of being killed every day are easier to convince to give up their souls for things. Food, means to fight or the death of a particular person, all those are deals that can easily be sold in a warzone. Even protection or a way out can be bartered for. # Bonus Program Whenever a customer refers to a new customer that makes a deal, the old customer accrues loyalty points, depending on the value of the soul. You can get up to 500 loyalty points for the soul of the sitting pope! In exchange for loyalty points, extra benefits can be got! It only takes 100 loyalty points to get the equivalent of a soul in services, but buying back your soul costs 1000 loyalty points. But such a good employee of Hell Inc. will come back there anyway after seeing the thanatologist. After all, they have corrupted some very valuable souls. And who'd give up 10 wishes for just their soul?! ]

[Question] [ In a world where society and culture are very similar to Medieval kingdoms of past ages, and moreover a world where there is no one conclusive ruler, but a region of small city-states which each have their own rulers vying for power, how could these states and lesser entities protect themselves from Dragon attacks? Are there any historical technologies that could have been employed to defend themselves from fire-breathing dragons? If not, are there any technological leaps that are not too theoretically far-fetched to incorporate with Medieval culture? Finally, if the dragons *couldn't* breathe fire (instead spitting acid or something of the like), would their defenses be possible then? **EDIT:** The kind of Dragon I'm talking about is essentially your standard large, red, firebreathing dragon - the quintessential dragon, more or less. No outside magical powers. I'll bend the question a little bit and ask as well if there are any interesting variations on dragons that could exist alongside normal culture and not be oppressively dominant? [Answer] Couple methods...I'd actually suggest a Roman legion was better equipped to fight a dragon than most medieval forces ever were (maybe the English were an exception due to the extreme importance put on bow use). 1. Siege weapons, in particular the Ballista and possibly the Lithobolos (basically a giant stone thrower). The Scorpio and the Cheiroballistra could also have relevance here. Anti-personnel artillery seemed to be a Roman specialization and would have had a decent effect if turned on a dragon. By medieval times, much of this technology was lost, and what was left became more specialized (trebuchet)...unfortunately these more specialized weapons were designed for taking down city/castle walls and wouldn't have been very good vs a flying target. 2. English longbow tactics. This is as much a way of life than anything...I believe it was Henry III that decreed all people, poor and otherwise, should be proficient with a bow or halberd (or bill). This gives a society where every member was capable of bearing arms. No matter where a dragon attacks, it's going to find a populace shooting arrows at it. This somewhat fits into the theory of "If you and I are running from a bear, I don't need to outrun the bear, I need to outrun you"...if a dragon has a choice between attacking a land where everyone was armed and ready to fire at it vs a society that's relatively defenseless, guess which one the dragon will attack? 3. Figure out what the dragon wants and give it to them. Dragon wants wealth? Start paying a tribute (bonus points if this results in a dragon protecting towns from other dragons because that town is paying them tribute). Do they want food? Start sacrificing animals and possibly ritual sacrifice humans to the dragon. Are they protecting their lands? Move the town elsewhere! 4. Mass crossbows. Unlike bows and the majority of medieval weapons, a crossbow is exceedingly simple to use (load, point, click, repeat) and a person can be trained on using a crossbow in an hour or two. They might not be the best at it, but it creates the scenario in #2 above where everywhere a dragon attacks, it's going to meet resistance in the form of arrows. 5. Nets. A net 'launcher' isn't that feasible, but luring the Dragon into chasing a group of hero's that snag the dragon in a net between two trees could be an individual 'heroic' effort to bring a dragon down. [Answer] ## The natural world has stuff that other species use to cope with the dragons It occurs to me that you won't have *only* dragons. Predators and prey are closely matched and evolve through an arms race. The dragon would not evolve such power unless he *needed* it against his prey and other life forms. I think about the [Larson cartoon](https://www.wikipedia.org/wiki/The_Far_Side) *the sheep that give us steel wool have no natural enemies*. Maybe dragons evolved because wolves **could not hunt them**. People might harvest fire-retardant grasses and pelts from their farming efforts. Other large animals may produce hard scoots that make excellent armor against *that specific threat*. ## Dragons are tough *why*? And as I alluded to earlier, the dragon will have its own predators. You would not want a worse one on hand, but there are small "predators" such as germs, parasites, scale mites, etc. ## Please *do* feed the dragons Finally, the farmers can efficiently feed the dragons too. The dragons will find that easier than fighting for each meal, and eventually will become dependent on the farmers, which they will then have incentive to *protect*. In short, **domesticate the dragons**. Shepherds did not kill *all* the wolves; their descendants now work as shepherds alongside the humans, or guard the flock against their wild cousins. If dragons are territorial, the best defense is to have the land occupied by an allied dragon. Maybe they are social creatures and [make good pets](http://www.imdb.com/title/tt0892769/). [Answer] A more inventive answer would be to use airspace denial techniques; assuming you can build a big, fabric shell and a burner of some sort to fill it with hot air, and then attach a tough rope or cable to it, you can create a crude form of a mighty annoying device called a [barrage balloon](http://en.wikipedia.org/wiki/Barrage_balloon) -- the lifted cable is very hard to spot while in flight, and a cable or rope can seriously damage even a dragon by injuring their wings. Even if they dodge it, having to maneuver around a network of cables and even lifted nets can be used much like a land army deploying caltrops, bear and pit traps, snares, and other such means to deny the foe use of an area and/or funnel them into a "kill zone". [Answer] If the dragons are malevolent and even moderately intelligent, defense **over the long term** is probably impossible, for a devastatingly simple reason: ### [Burninating the countryside, burninating the peasants.](https://www.youtube.com/watch?v=7gz1DIIxmEE) The answers so far have mainly dealt with short-term tactical considerations, and have done so quite well. However, there's a strategic side to this question: **medieval societies are fundamentally dependent on the harvest.** Without reliable yields of grain, people will starve and disperse. No more towns, castles, etc. The land will be depopulated. ("Desolation of Smaug", indeed!) So, how effectively could the fields, barns, hayricks, oxen, and so on be defended against even one fairly tough fire-breathing dragon? **None of the *tactical* answers discussed above seem up to the task.** All of them seem to rely on **concentration of distance attacks,** with some good attention paid to driving the dragons into established kill zones. (+1 to @Shalvenay for that one.) However, none of these is a reliable means of defense of a broadly distributed agricultural base. **You can't concentrate attacks on a dragon that can go wherever it wants to destroy the crops.** **This is not unlike the problem of Viking raids in medieval seacoast Europe (mainly Britain and France)** when [the Vikings could show up when and where they wished, do their looting and killing, and be back out at sea before the local barons could arrive to give battle:](http://www.hurstwic.org/history/articles/society/text/raids.htm) > > The Viking raiders depended on the superiority of their ships in order to make their raids a success. The shallow draft of Viking age ships meant that they could navigate shallow bays and rivers where other contemporary ships couldn't sail. The broad bottom of the Viking ships made it possible to land on any sandy beach, rather than requiring a harbor or pier or other prepared landing spot. These two factors made it possible for Vikings to land and raid in places that their victims thought it impossible to land, contributing to the surprise of the raids. Additionally, the efficiency of Viking ships under sail meant they could outrun contemporary ships under favorable conditions. And the combination of sail and oar meant that Viking ships could outrun contemporary ships under unfavorable conditions as well. These two factors made it possible for Viking raiders to depart from a raid with little danger from any defenders who might try to give chase. > > > **Flying dragons would have a much stronger advantage in tactical mobility than that conferred by Viking longships; and the horrifying effectiveness of dragonfire against agricultural targets would be decisive.** As a result, your answer is going to be limited to two reasonable worldbuilding techniques: * **Modify your dragons,** either in behavior or in physical capability, to make them less likely to starve human opponents out. * **Provide your medieval societies with some kind of enormously effective technique for killing dragons, or at least *very* effectively keeping them from destroying the food crops and the peasant base.** This is a terribly difficult thing to do, since one loss means a starvation winter... it might need to involve magic; or it could involve the "make-allies-of-dragons" strategies described by @JDługosz; or appeasement as mentioned by @PipperChip. It sounds, from the wording of the question, that your story purposes are best served by at least some prospect of meaningful combat. I hope you can pull it off; this sounds pretty cool. [Answer] When I was a little kid, I had a collection of recordings on vinyl disks, some of which went with booklets to teach reading. One I remember seemed to be the audio (only) of a cartoon, perhaps a Disney short or segment but I don't know what the original presentation was ([Google does. Love this 21st century!](http://disney.wikia.com/wiki/The_Sword_in_the_Stone)). It concerned a duel between magicians, with the final rule, "no disappearing!". After various transformations where each could better fight the other's current form, one becomes a **dragon** and that appears to be so powerful as to be indefensible against. They he says "hey, no disappearing!" Or words to that effect as the sounds of the battle stop. The opponent speaks: "oh, I'm still here, but I'm very very small. **I am a germ.** A rare, dragon, disease. And you have caught a bad case of me." The morals are several: the very smallest can beat the very largest, completing the circle, and cleverness can beat overt force. Especially for the best story, I'd follow those themes. The defense is not a bigger missile, but *subtle* and understated. *sure, dragons are no problem since they are huge and blundering and have so many points of failure. It's mosquitoes that are the real hazard.* * methane or other gas makes the dragon fire *misfire* and hurt itself. * fine dust dispersed into clouds are annoying in many ways, oh, make them flammable too. * tiny darts with poison and diseases * cultivate dragon pests like scale mites so the dragon won't want to come near these pests. Of course, you can have your own trained domesticated dragons. They can easily win because they are trained fighters and have human direction in battle, and artificial enhancements like protection over vulnerable spots, or selective breeding to be badder fighters even at the expense of overall fitness in the wild. [Answer] # Bolts, Lots of Bolts Crossbow get a bad rap in fantasy sometimes, but the truth was that they were very powerful weapons which could pierce knights' armor. Even low-power [crossbows can penetrate well](https://www.youtube.com/watch?v=Oq2ni79BK8M). In fact, there are many nations with [laws against crossbows still](http://en.wikipedia.org/wiki/Laws_on_crossbows). If their scales are thick like plate armor, a [crossbow bolt could go through](https://www.youtube.com/watch?v=KCE40J93m5c). In fact, modern crossbows can still [go through modern armor](https://www.youtube.com/watch?v=1nLRymWv-CA)! Obviously, bigger dragons would merit bigger crossbows... or a [ballista](http://en.wikipedia.org/wiki/Ballista#Middle_Ages)! A little know fact is that [cannons were uncommon](http://en.wikipedia.org/wiki/Cannon#Medieval_Europe) in Middle Age Europe, but not entirely unavailable. If arrows and bolts don't make it through a dragon's skin, a cannonball might. # Fouling Up Flying The other option is to have weapon which foul up the dragon's ability to fly. Many birds, for instance, cannot fly if a [wing is damaged or "clipped.](http://www.vcahospitals.com/main/pet-health-information/article/animal-health/wing-clipping/939)" A dragon could be downed if a large enough nets, [bolas](http://en.wikipedia.org/wiki/Bolas), or [grapeshot](http://en.wikipedia.org/wiki/Grapeshot) were used. Once downed, lances, halberds, crossbows, and perhaps other weapons may be able to deal with the dragon. At the very least, this tactic may be annoying enough to make a dragon not want to bother with people. After all, deterrence is a viable strategy. # What About Fire/Lightning/Etc. Some simple countermeasures for each of these: * Fire: Use [metal pavises](http://en.wikipedia.org/wiki/Pavise), giving you cover. Brick and Mortar can only be set on fire with great difficulty. * Lighting: Get a lightning rod. Okay, lightning rods were not invented until later, but it's not inconceivable to get this development. Knights' Armor will cause electricity to flow around the knight into the ground *[if the knights are in contact with the ground](https://www.youtube.com/watch?v=eNxDgd3D_bU)*, so they're actually well protected. Actually, a metal pavise would work like a lightning rod... * Acid: Wipe it off before it eats through. Carry lots of water or other basic substance to counter-act it. Once again, the pavise defense could work well here, if coated in a basic substance. Alternatively, it could be a one-time use defense. * "Cold" Breath: This one comes from RPGs. Shields or pavises would work really well, since most icy breaths appear to be shards of ice shooting at foes. # Appeasement This is the most cowardly defense, hardly one at all, but keeping dragons at bay by giving them what they want. If they can be bribed, it may be worth it. It's practical to know when you're beat, and simply try to minimize losses. [Answer] Assuming no magic in this scenario, the best bet for survival on the human's end would likely be avoidance as stated in the comments. Moving underground or into caves narrows down the number of directions a dragon could approach and more or less mitigates the advantages they gain by flight. Barring that, however, ballista and other similar contraptions are feasible for the time frame and in fact did exist. Though perhaps not a guarantee for defense, it stands to reason that individuals would quickly hone the skills necessary to track and shoot down dragons with such weapons to survive. With dragons becoming, presumably, one of the primary threats to these people it would also be reasonable to assume that they would focus research in improving these weapons as well as developing new ones, thus speeding up discoveries in ranged weaponry compared to historical progress. As far as creative, low-tech solutions to dealing with flying threats: In the book series "The Black Company", there is a point in which, to counter broom-flying wizards/witches, the enemy who have no magicians to aid them send up large balloons with thick cables/tethers attached to them. The tethers are lined in spikes and other nasty things and put up in a pattern and volume that would foul up any sort of flying adversary. While certainly not fool-proof, it's a start and offers a similar protection as walls against ground-bound adversaries. Combined with ballistae and other such machines, it may be enough to deter or at least slow down dragons. **Edit** In addition I find it likely that they would develop some sort of early warning system, and, if not having the entirety of their structures "dragon-proofed", at the very least they would have some sort of shelter created after the first few attacks. Like a system of towers using light to carry warning, or some other such set-up, to give warning of any dragon sightings. This would, hopefully, give time for the people to get into the dragon shelters, whether they be stone buildings, underground cellars or something else, so at the very least there's no loss of life to accompany property damage. **Edit 2** In response to your edit, if I recall correctly in the D&D universe there are a couple types of dragons (I want to say maybe Bronze or Brass) that are more focused on gather knowledge than laying waste to the country side. These, should they choose to communicate with humans, could certainly prove to be almost benevolent or at least neutral to humans so long as they comply in it's requests to garner knowledge. Though it could still be a hazard as it is still a dragon with all the might and fury that can bring when displeased. I think the example they gave was of the Brass (or bronze, or copper, whichever one of the metallic dragons it was) burying humans in the ground up to their neck so they could be questioned and not try to run away. Not exactly ideal, but presumably they're released when the dragon is done, better than being eaten or killed just because. [Answer] Poisons. Traps. Go for the eyes when the dragons sleeping. Kingdoms with large armies can get the job done by sheer numbers. Start some legends about dragons parts having magical uses. There won't be enough dragons to fulfill the demand. [Answer] # Hit them back, until they are all dead Defending against an adult, flying, fire breathing dragon its quite a difficult task. If the dragon lands in the middle of your army most probably you can kill him without too many loses; but the issue is that you cannot be your army in war footing at all times, and you cannot protect all the settlements and fields with it. Fortunately, men are intelligent creatures$^1$, so the alternative is very clear, and has already been used in history against raiders, marauders, and pirates. You attack them back. And, since dragons are animals and cannot be someted by fear, you have to exterminate them. Depending of your level of knowledge of dragons/science, you may try first with the easier methods. For example, if poppy seeds make the dragon feel bad, just wrap a few bags of seeds around and cow and let a dragon eat it. Then you follow it to see if it drops dead, or unconscious enough to be easy to kill. Rinse and repeat. Another way would be sending scouts around to find if there is somewhere they want to hang around, or if there is a favorite river the like to drink from, whatever. You send your army there and deal with the dragons as they appear, instead of waiting for them to appear in your backyard. If dragons collect food for winter, your army appears there at the end of the autumn and burn everything. If the place were the dragon nests are, each season you send your army and raze all the nests to the ground. While this campaign is ongoing, your villagers would need to keep a "safe" lifestyle to avoid attracting dragons, examples would be: * Safe dwellings (in deep caves, or partially underground with tunnels for supply storage and emergency exit). * Keep lookouts for villages and/or fields. * Avoid open spaces... taking the cows to pasture in the woods may be more difficult that in the grass, but beats losing half the cows to a dragon. * Getting out when dragons are not around. If dragons are daytime creatures, try to get out only in the dark. $^1$ I am assuming the dragons first ate all of the dumb people, which is a reasonable supposition. [Answer] Defending against a dragon is going to depend greatly on what level of defense you are trying to employ and what kind of dragons you are trying to protect against. The primary issue with trying to apply actual medieval technology to the process of fighting dragons is that dragons were never real and there for people never had to develop things to fight them. The impact of an apex predator like a dragon would have on a developing society would have had long reaching impacts on the development of that society, assuming that the dragons didn't just show up one day out of no where. If dragons have just shown up unexpectedly, there is very little effective defense that medieval people could mount, lacking any sort of concept of how to kill or drive off such a thing. However, if dragons have existed as long as the humans have, they would have developed techniques for dealing with them long ago and refined them over time to be more effective. By the time that humans were able to make large city settlements, they would have first have had to resolve how to keep dragons from destroying smaller single family or tribal settlements to reach that point. Think about the way that humans had to first resolve how to prevent being killed by other predators before we could being making more permanent settlements. One of the earliest methods unfortunately doesn't really dissuade a dragon and in fact might even attract them, fire. The first challenge here is to develop some methods that humans could use to drive off dragons with very primitive tools and then extrapolate to larger and more modern devices. Some suggestions ranging from direct and lethal to more indirect and denial: * Pikes(<http://en.wikipedia.org/wiki/Pike_(weapon)>): basically a long sharp pole. Very easy and simple to fashion and can be braced against the ground. A swooping dragon would be at a great risk of impaling themselves on these poles and by modern times, the pikes can be fashioned with steel supports and blades to increase the chances of critically wounding a dragon. The down side is that the user is putting themselves in direct line of contact with the dragon and failing to kill or stop the dragon most likely means they will be killed. * Atlatls(<http://www.atlatl.com/>): This one always gets looked over in favor of bows, but as far as early missile weapons go, it can't be beat. Early people could have developed these and made adjustments that allow them to take down or deter dragons by throwing sharp sticks, rocks, or various other payloads that could injure or drive off a dragon. Much like the pike, advances in technology leads to bows and crossbows, but could also lead to more advanced version of the primitive tool. Easy to use, even easier to make and can throw things other than arrows to deliver allergens, fuels, etc. * Fire resistant construction and prevention: People facing a fire breathing predator would have long ago found ways to deal with fire, perhaps using more clay, brick, and stone over wood and thatch. Using materials that are resistant or immune to fire is going to be critical to surviving against dragons, but also requires you to have reached that technological benchmark without being hunted to extinction first. People would also likely have developed fire resistant clothing using natural oils or extracts that keep things from burning. * Poisons: Assuming that dragons are not particularly smart, putting out a prey animal that has been fed or laced with a substance lethal to a dragon could be a great way to get rid of one. It shows up, eats the poisoned sheep, goes to its nest and dies. Variations on the dragon concept could also make the task easier. Dragons are large apex predators and require a lot of food. Reducing their size and therefore food requirements could make it so that they are less likely to harass human populations, similar to how wolves avoid people because the risk out weighs the reward of eating human guarded herds. Dragons, being flying animals, may also not actually be as resilient as some settings describe. Birds are actually quite fragile, and dragons could be made to be similar, thin scales, hollow bones, unable to handle large weights. Reducing the amount of fire, how often they can use it, or removing that ability all together can make dealing with dragons much easier. If you can trick a dragon into using its fire breath on a resistant target, then that threat has been dealt with. [Answer] Knowing the history of humanity, I expect they'd figure out a way to **capture them**. If nets don't work, use chains, if the chains break make them heavier. Many people would die trying, but eventually the technological advance would catch up with the dragons. Then it's just a matter of doing it a few more times, breeding them, and raising the young amongst humans. Voila, instant military domination. Why, you could write some sort of gritty seven-book epic fantasy series about it. [Answer] Many people have suggested taking massive, large-scale strategies that involve the entire population. Instead, create a dragon response team, something akin to elite minute men. Take your finest soldiers, and train them in effective ways of killing dragons (e.g. ballistae) as well as specialized methods such as 3-man chain teams to bind the legs, wings, or jaws, or weapons to peel off scales and stab through the hole. There would probably need to be a warning system of some kind, to (a) signal for the peasants to get to the dragon shelters or caves; and (b) signal the response team to gear up. Also, a ballista with a chain attached to the bolt (i.e. harpoon gun) would be useful in keeping the dragon on the ground for the strike team. Upon missing, the chain could be unattached and a new one loaded in, or possibly reel the bolt back in to be fired again. [Answer] as in the witcher book series, there is a peasant that stuffed some sheeps with poison, the dragon attacked the herd, ate them and died of course, he gained the ire of knights and other professional dragon slayers, who feared that other peasants will get similar ideas and then they would be out of work. [Answer] Socio-political systems are technologies. They are developed and refined as people navigate their lives and experiences within the frameworks of their culture and environment. Much like dragons, the vikings (and other raiders) of real life presented a threat that small communities could not effectively deal with on their own. Feudal society is almost a direct outgrowth of these kinds of pressures upon agrarian city-states such as those described. Individual city-states do not have the economic power to fund the kind of on-demand skilled military force that is the necessary response to a dragon incursion. Through collaboration and subordination, valuable regions can be assured greater protection through the redistribution of material resources perhaps more plentiful elsewhere at minimal cost. The existence of a trained standing military force (knights) which, due to feudal arrangements, is distributed thoroughly throughout civilian populations is an effective and specialized response against spontaneous small raiding excursions of the sort that you seem to be imagining dragons making. In cases wherein dragon occupation is achieved-- a settlement or region being dominated and its local military proving insufficient-- the ultimate authority of a King allows for the potential to raise the necessary forces and to ensure those forces are sourced in a politically-sustainable manner. Regions that are occupied may be left occupied when the cost of liberating them is deemed to be prohibitive, but the cost will not be prohibitive in all cases. In terms of the actual slaying, dragons of the kind you seem to be assuming are normal tend to lair in defensible underground locations-- high mountain caves and such. This use of terrain allows a Dragon put on the defensive to effectively negate any numerical advantage human attackers might have, within genre (outside of genre the humans might maintain a siege or send so many soldiers that the human dies of exhaustion, but both options wouldn't work with, for example, Beowulf's bane). Furthermore, the jets-of-flame manner of attacking is significantly more effective against lightly armored rank and file infantry than heavily armored elite troops. Thus individuals or small groups will be the desired norm for the Dragonslayer. Dragons seem to generally be able to sneak from place to place fairly quickly and without much time to respond. Potential dragonslayers must be able to travel quickly in order to have any hope of chasing down and outmaneuvering a dragon, or they must successfully track a dragon down to its lair, which is not an easy task. Dragons, as the physical incarnation of greed, hoard treasure. Dragonslaying is thus extremely profitable, and-- as dragons are quite rare and take a long time to come to be (via reproduction or spontaneous generation or curses or however your dragons come to be)-- dragons will thus quickly become very rare and reportings of a dragon will be responded to quickly by a number of would-be slayers as the dragonslaying industry progresses over time. Thus in the beginning of successful anti-dragon warfare horses are very much desired, and as the industry progresses they become almost necessary. Horses are very expensive in medieval societies, so this greatly limits who can enter dragonslaying as a profession. The spoils of dragonslaying are, as previously mentioned, great, however, so successful dragonslayers will have no trouble maintaining their status barring political action. Plate armor is probably the most effective form of armor against dragons. The full body covering with internal padding should render one practically invulnerable to its flame except for direct attacks through the visor. The issue then becomes dealing with the dragon's thick hide and multifarious sharp body parts, which is largely a contest of skill, strength, and weapon quality. The social generation of knights in shining armor is thus a reasonable solution to dragonslaying, as well as a classic one. Note that the above assumes the standard, flightless dragon, such as that found throughout Nordic myth, rather than the winged versions common in modern Tolkienian fantasy (or Tolkien's inspiration, Beowulf's bane). Flighted dragons nonetheless seem to dwell in the same sort of places, which obviously prevents flight while in its lair, so the method of dealing with them would rely exclusively on hunting down and killing them proactively as killing them 'in the field' would be technologically infeasible until ballista technology is recovered. As the Renaissance dawns you could make use of such equipment as the [Polybolos](http://en.wikipedia.org/wiki/Polybolos), rendering wealthy settlements immune to the wrath of dragons. [Answer] An easy guess is to assume they know what the dragon is allergic to, lets say the dragon is allergic to a type of flower, you can expect people cultivating this flower and using its properties against the dragon in some way . Another proven method is poisoning the dragon's food assuming that people know what he eats and that they leave dinner for the dragon somewhere, I see this method as more effective. Poisoned arrow or poisoned food. The use of chemical reactions seems more effective towards a dragon because using force vs force is riskier assuming that the dragon can fly and spit fire. [Answer] ballista and cannons chain shot and buck & ball will work well mortar traps would work well assuming low intelligence, or mortal defense to create safe areas for high intelligence. really you need to define how intelligent they are because that going to have a huge effect on what will work. [Answer] **Starvation** A dragon's greatest weakness? The sheer amount of energy he needs! He's huge, he can fly, and he can breathe fire. All that energy has to come from somewhere, which means he needs to be constantly eating, and eating well. He won't last long if you find a way of cutting off his food supply. Your fields with cows and horses will have giant spikes in the ground so he can't just dive in and take them. Your hunters will hunt the large animals in the wilderness to near extinction. The people will hide in networks of underground tunnels whenever he approaches, defended by tough, lean warriors outside covered in spiky armour that he can't just swallow whole without damaging his mouth and throat somewhat. Each meal must cost him more in calories than what he gains from that meal. Or better, if you find the cave he lives in, block it up while he's asleep in there. Hopefully he doesn't eat trees... [Answer] ## Steal the eggs Easier said than done, but if you manage to steal an egg, you could raise it and have your own domestic dragon. You may have to lure the dragon out of its nest, but unless the dragons take turns and never leave the eggs alone, it shouldn't be necessary. And you only need stone age technology to do that. [Answer] Have the people live underground or deep in cave systems that the dragon cant get into. No dragons inside Moria (LOTR). The people can dig these themselves. It would be a massive project but it can be done with enough people working together. With torches and properly dug shafts you could still get light in there, and air. Water is not a problem as a stream could be diverted to cut through. If the cavern is big enough you might even be able to bring livestock in too. The only danger will be when people absolutely have to go outside, say for trading, farming, hunting or whatever. Something to consider about dragons is that they're so big, and are so predatory, that their only true competition is another dragon. To that end they probably avoid one another and stake out a territory for themselves to hunt it. So unless they're mating I would imagine that a given territory only has the one dragon in it. Still dangerous, but not as bad as a swarm of them. ]

[Question] [ For the purposes of the question, it doesn't really matter if the creature's a continent-sized amoeba or a particularly large kaiju. Speed of thought is relatively painfully slow in organic creatures, since it uses electrochemical processes. It is so slow, in fact, that the speed can be expressed in *meters per second*. It's not too terrible for peripheral signals like from limbs, as it will just make the creature react more sluggishly. But what about the brain? If a creature's brain is 100 meters in diameter or more (say, aforementioned sentient amoeba for instance), it will take a neural impulse around a second to propagate through it. I feel this is not enough for high brain functions to exist, and it can easily cause different part of the brain to lose synchronization, so the question is, **what evolutionary adaptation macrolife can have to circumvent the neuron reaction speed limitations?** [Answer] ## Solution: neurons that funnel flashes of light. Have you heard of [fiber-optic cables](https://en.wikipedia.org/wiki/Fiber-optic_cable)? No? In a nutshell, the cable doesn't serve to transfer electrical energy but instead funnels photons within a reflective cable. This technology is what allows the internet to function worldwide. This is clever, because nothing is faster than light when it comes to crossing long distances quickly. All you need is a source of light, means of funnelling it in the desired direction and a receptor at the other end. **How are Kaiju's supposed to make use of this in the first place?** [](https://i.stack.imgur.com/iB6Wf.jpg) Organisms have mastered the usage of light since prehistory approximately 3.5 billion years ago. Photoreceptors have practically evolved alongside intelligence, without them we wouldn't be as complex as we are today. Likewise, bioluminescence is an extremely old trait shared my many species i.e. fireflies, anglerfish and some species of jellyfish. Nocturnal animals like cats have reflective cells lining their retinas called Tapetum Lucidum. **Perfect. Life has a means of producing, reflecting and detecting light.** ## There's two ways this can work: **Intracranial optic cables serving as neurons**, which essentially allow a gigantic brain to think at a reasonable speed. This doesn't mean the Kaiju will be smarter. No, the limiting factor is the size of the cables. To prevent the light from 'leaking' from the cables the reflective layer needs to be a certain thickness. Otherwise a single nerve firing off a light signal would cause a ripple effect which would give the Kaiju a seizure. **This is the least optimal arrangement but it allows for comically large brains**. **Peripheral nervous system using optic cables**, which completely negates the lag Kaiju would normally have. Signals sent from the brain are now instantly relayed through the body to the extremities. This is far more efficient than having a secondary brain. **No doubt, this is the optimal way to go**. Both solutions imply the nerves connecting different body parts will be thick hollow structures with reflective inner surfaces. One end would have a bioluminescent organ while the other photoreceptor cells. Either the organ flashes when it receives a nerve impulse or a valve open and closes the cable. Either way is good. [Answer] The most basic adaptation to faster neural functioning is the ability to precipitate metals. Once a life-form has the ability to precipitate metals and build metal structures within its body, it is not a particularly great evolutionary step to neurons with metal axons. If we have a metal axon with a seperate metal core, like a biologically-created coaxial cable, we've stepped up the speed of neural transmission from hundreds of metres per second to near light-speed. The main delay will then be the time it takes for a neuron to depolarise and the wave of depolarisation to travel to the metal axon. From there, the voltage differential will propagate at light speed to the far end of the axon where the dendrites will depolarise at the slow speed, and transmit their signal to the next neuron via molecular diffusion of neurotransmitters across the neural gap. It might seem that a metal axon would be rigid, and could not bend, but this axon would be many times thinner than a hair. When metals are that thin, they bend very easily. They would be no more fragile than common myelinated neurons. As to what metal might be used... silver would provide the lowest electrical resistance, followed by gold and copper. However, the scarcity of silver and gold might mean that copper is used for no other reason than its relatively low resistance and relatively high availability. So... with metal axons, an organism could be hundreds or thousands of metres long, yet still have the same speed of neural transmission as a much smaller creature. Edit Since there is some misunderstanding as to how this works, I'll explain further: A regular [neuron](https://en.wikipedia.org/wiki/Neuron#Anatomy_and_histology)'s cell wall has a charge across it. The cell wall is a poor conductor. Within the cell wall are voltage-sensitive ion gates. When neural junction activation causes sufficient depolarisation as a field effect around the junction, the voltage-sensitive gates open briefly, sending a wave of depolarisation across the cell membrane. Since the gates aren't particularly fast, and since the field effect of the charge is limited, this limits the transmission speed. Now, if we were to precipitate metals inside and outside the cell membrane, the metal layers, being conductive, would transmit the voltage along their mass at lightspeed. In effect, there would be a continuous metal fibre inside the axon, and a continuous metal sheath would replace the periodic myelin sheath. So, instead of a long axon with slow gates and perhaps myelin to make the axon a little faster, we'd have in effect a cellular-scale [coaxial cable](https://en.wikipedia.org/wiki/Coaxial_cable), where the insulating layer between the conductors would be the cell membrane. As I have said, this will transmit the voltage differential from one end of the axon to the other at lightspeed, from where the usual ion gate depolarisation effect continues. [Answer] You should consider that human brains have limited large-scale synchronization, and they're a lot smaller than 100m across. Clearly you can get human-equivalent intelligence in a human-sized brain that's a thousand times smaller. Fictional kaiju don't seem to demonstrate any kind of superhuman intelligence, suggesting that their thinky wetware isn't obviously more capable than our own and as such doesn't actually need to be a whole lot bigger. You could have a little blob for consciousness, and then just an awful lot of infrastructure to control all those muscle cells that would let an enormous animal actually move about. Now, making a conscious decision to waggle an arm obviously has an awful lot of latency associated with it if your brain (or body) is tens or hundreds of metres across, which could be quite annoying, but there are ways around this. You might not need conscious control over every last muscle... perhaps much of the actual detail of co-ordinating the motor neurons that drive a limb is delegated to local semi-autonomous brain regions and other chunks of neural tissue distributed throughout the body and the limb in question. There's a reasonable chance that [octopus brains are organised a little like this](https://news.agu.org/press-release/researchers-model-how-octopus-arms-make-decisions/), with individual arms having a reasonable amount of independent action, with a central brain that co-ordinates but doesn't directly control ever little detail. Maybe kaiju brains are more distributed through their bodies, and maybe they operate much more like a closely knit group of semi-independent (though not necessarily conscious) brains. > > what evolutionary adaptation macrolife can have to circumvent the neuron reaction speed limitations? > > > The lazy answer would be to say that they evolved nerves that operated fast enough to enable them to move and act in a way that furthers your plot. Our nerves already have some adaptations for improved conduction speed in the form of [saltatory conduction](https://en.wikipedia.org/wiki/Saltatory_conduction), but there's nothing to say that what we have is necessarily as good as nerves could ever get. Alternative electrochemical signalling mechanisms could be much faster, or maybe just plain electrical signalling given suitable insulation forming. Other exotic things like internal [waveguides](https://en.wikipedia.org/wiki/Waveguide) that would allow sonic or ultrasonic signals to propagate at the speed of sound in a liquid (several times that of the speed of sound in air) or maybe hollow structures (maybe rigid, maybe filled with clear liquid or other material like a kind of fiber-optic) that use bioluminescent signalling, etc etc. [Answer] # Does it need full brain synchronisation? There's a few misconceptions here. A brain is not a computer. We don't need synchronisation in such detail. The method used is more flexible. Also consider that information can be processed in a brain structure and then send to the other side of the brain for further processing. Higher brain functions also don't require speed in most cases like movement does. You don't need to have an answer ready in a nanosecond. Now consider higher brain functions. If higher brain functions would be affected negatively, why put them far apart in the first place? Humans have higher brain functions with our current brains. Why not just put important brain areas close to each other as humans have? There should be no reason for brain areas to talk to each other so far apart. That raises another question. Why do you need a brain 100m in size? If you just supersize a whale, you don't need extra brain to steer the thing. You can do with the same brain as before. Extra brain offers assistance with control for examole, but isn't required. A fly can fly it's wings as it has many routine 'programs' inside it. It isn't a conscious effort to beat a wing. Same for heart rate, blood vessel constriction and much more. These processes are either handled indirectly or if directly they don't necessarily need complex brain structures to be controlled. ## Summary You can make due with less brain to steer increasingly large creatures. Higher brain functions are very much possible in large brains, you just need to put the right brain parts together. Synchronisation isn't the same as with computers, allowing for more flexibility in brain communication. [Answer] **The Brain has a Smaller Brain.** A lot of the physical motions do not require the brain. They only route through the spine. Humans already do this. Most of the walking and running action does not require the brain. The brain can focus on speeding up, slowing down, avoiding obstacles and such. Keeping in pace and shifting weight on uneven ground only uses the spine. The part of the giant monster's brain that manages intelligence is not much bigger than a human brain. Asynchronization is not a problem for this sub-brain. When the animal wants to move forward the microbrain sends signals to the legs that say "move forward". The legs nearer the head get the signal first and start moving first. The legs near the end start moving last. The legs know how long to delay after getting the signal in order to keep them in step with each other. This calculation is done in the part of the spine where each leg joins. Each individual leg then manages its own gripping and balancing issues without sending signals back to the spine. If the creature needs to suddenly stop the brain sends the "STOP" command down the spine. There might be a delay of several minutes until all the legs get the message. But this delay is rarely noticeable to an observer, considering how physics demands each leg takes ten minutes to take a single step in the first place. [Answer] ## In its natural environment **The same way we do, by sheer size.** When you attempt to swat a bluebottle or similar fly, it can see, and react to your motion, faster than you can see that it has done so. However the bluebottle is no threat to us, much in the same way that nothing our size in its natural environment would be a threat to a kaiju. You have to be as big to be a threat, and as such suffer from the same neural delay. ***There is no evolutionary reason to solve this problem.*** or even to see it as a problem. [Answer] Your mega creatures can circumvent the issue of requiring large brains by having multiple smaller brains to handle multiple levels of tasks. If each individual brain is only interested in its own specific function, ie keeping the digestive system going, or repairing damaged tissue, or movement, then the individual size would not need to be as large as you anticipate. You would require a central processing unit, but this again could be relatively small, because it would only be required to coordinate the lower brains, and let them deal with the basics themselves, leaving it more energy for the higher functions, unless that is another level of brain again.. There would still be signal delay, especially between the individual brains, but this system could at least limit the need for longer-distance signals, and keep the possibility of higher function in at least one of the brains, if not more. From an evolutionary standpoint, I can see this as a possible future path, as most animal brains are already compartmentalised to a large degree. Why not take it to its (il)logical extreme? [Answer] ## Because of [handwave], macro-creatures are slightly prescient, and begin reacting to stimuli before they happen Instead of sending messages faster, why not have your giant creatures start reacting sooner? As in, sooner than the thing they're reacting to has happened. Sure, this is impossible based on our understanding of causality and physics. But so are (most) extremely large creatures, so you're already handwaving pretty hard. The advantage of this, over some biological peculiarity merely allowing for faster transmission of messages, is that it comes with a built-in story hook. If once we figured out that giant creatures were breaking the laws of physics (in a potentially exploitable way!), you have a motivation to want to defeat the thing, but not kill it - at the same time that you've just made it very, very hard for the characters to actually accomplish it. (How do you beat something, without using overwhelming force, when it knows seconds or more before you've acted what you're going to do?) [Answer] **The speed of thoughts** Let us consider the factors affecting the speed of thoughts **Neuron Size**: Signals travel faster in neurons with larger diameters than those that are narrower. **Complexity**: If more number of neurons are involved in a thought process, then absolute distance traveled by the signal is greater, which takes more time. **Myelin**: The speed of the signal transmission is influenced by an insulating layer called myelin. Myelin is a fatty layer formed, in the vertebrate central nervous system, by concentric wrapping of oligodendrocyte cell processes around axons. Myelin speeds up conductivity and the transmission of electrical impulses and conduction velocity in axons. So speed of thought may be increased by * increasing neuron size. * Less complex thought process. * Myelination [Answer] ## Frame Challenge: True brain speed is measured in synapses, frequencies, temperature, and noise: distance over time is just an estimate based on human sized/shaped neurons. Because we know the average length, diameter, and temperature of a human neuron we can estimate signal speeds in meters per second, but this is a gross over-simplification for the problem you are looking at. Assuming your megafauna is not also mega intelligent, it's 100m wide brain may not have any more individual synapses than other animals. The brain transmits data by electrochemical processes. The electrical part where the signals moves from one side of a neuron to the other happens at relativistic speeds. Since your cell is mostly made up of water and fats, this puts your [Relative Permittivity](https://en.wikipedia.org/wiki/Relative_permittivity) at somewhere between 40-90 giving you a signal speed of [~47,000-32,000 km/s](https://www.vcalc.com/wiki/DavidC/RF+Velocity+of+Propagation) The slow part of the process is the chemical part where an axon terminal waits until enough pulses of electricity are received to release a neurotransmitter which is a chemical that then has to react with the adjoining cell's dendrite to propagate the signal into the next cell. So, a larger brain with the same number of synapses will not be noticably slower than a smaller brain. In the human brain, neurons are typically about 6-100mm long... so in your megafaunna brain, those same neurons could be about 14-230 meters long. Such a cell would only take less than 0.000008 seconds longer to transmit an electrical signal from one end to another as the shorter human neuron. ## Your mega fauna could actually think and react faster, not slower The other big constraint with think time, is signal certainty. The tiny cells in your brain being all mixed together have to compete against signal lose and interference. In school, most of us learned that a Myelin Sheath is like a wire to make the signal go faster, but this is wrong. A Myelin Sheath is actually more like a series of capacitors designed to break up a continuous signal into discreate pulses of exact voltage and constrained frequency. This increases the clarity of the signal. With a more clear signal, the brain does not need to wait as long for a change in pattern to become obvious; so, the the synapse is able to begin reacting sooner. By making your neurons bigger, you have more space to spare to insulate your axion from outside interference and boost the actual signal strength. This means that a big brain can operate at higher frequencies without the signal becoming unclear which would boost how quickly synapses could respond to changes with a high level of certainty. A typical human neuron operates at about 340±10Hz. This means we can only send a signal through about 34 neural connections per second based on how fast our [sodium potassium pumps](https://en.wikipedia.org/wiki/Na%2B/K%2B-ATPase) work. By increasing the cross-sections of the axions about 6500 fold, we now have up to 42 million times as much bandwidth as a human neuron. Not only can we use this added diameter to reduce interference, but using parallel axions like we see used in the auditory nerve, you can achieve frequencies in the megahertz or maybe even gigahertz range allowing MUCH faster response times in signal recognition. The chemical part of the neural connection may not be sped up at all, but speeding up the recognition system should make the recognition part of the system take about 0.03 seconds less time per synapse which would more than offset the extra time it takes the electrical signal to travel. ## So, why do so many sources measure neural electrical speed in m/s? In short, because it is easier to understand. Most authors don't understand/differentiate between the speed of the actual electricity and action potential propagation. As Austin pointed out in comments, a human neuron can send a signal at anywhere from 0.1-100 m/s. This very wide range of speeds is not proportional to ~50% electrical propagation speed differences between common organic compounds you find in the body. Instead, it is affected by how long and wide the neurons are, how well it is designed to filter out noise, and how high of a frequency it can generate. At human sized neurons, even a Myelin Sheath can only do so much to filter out noise from adjacent cells meaning that even a longer cell needs more pulses to get a clear signal which effectively creates a speed-to-distance relationship (it's not 1:1, but it is a correlation) When you look at squid axions for example, they can achieve "faster" signals with thicker more distributed nerves for the kinds of neurons they have. You also see signals "slow down" at colder temperatures. However, electrons have less resistance in cold mediums, not more. This "slower" signal is because the chemical reactions of the sodium potassium pumps slow down reducing the frequency of the signal. If the electricity was only flowing at 0.1-100 m/s then a diameter higher diameter, warmer neuron would not increase the speed of the signal. [Answer] # Neural fiberoptics To truly increase the speed of neurons we can change how they work. We can use fiberoptics in the neurons instead of electricity. Fiberoptics is a way to transmit light along transparent cables. As long as the bend in a cable isn't too large, it'll bounce all the way to the end. That means we can use this as a building block for fiberoptic neurons. The neuron will have a bioluminous property. It can be off or change brightness. On the receiving end you have a photoreceptor like in the eye, but only a primitive highly sensitive version. This will translate the signal and stimulate it's own bioluminous organ. This can be seen as a analogue signal, in contrast to the electric potential. Though stimulating a neuron is analogue, the electric potential is an on or off mechanism and thus digital. It can only transmit information via patterns. A fiberoptic neuron can thus put more information in a signal. This can be further improved by adding different signals. Just like in our eyes we can select specific wavelengths that the neuron can perceive. If you have two or even more different receptors, you can add multiple wavelengths to a single neuron. As a quick example, a single neuron pathway can fire red, yellow and blue, allowing for 3 signals. More information at once! The true improvement here is speed. The synaptic cleft is removed, which was the slowest part in transmission. It's function is replaced by the gradient of the light and the sensitivity of the receptor. In addition, the signal will go as fast as the speed of light, though a bit slower as it is still bouncing so not a straight line. A fiberoptic neuron increases speed by insane amounts, is flexible, can handle more information per signal, can have multiple signals per strand, can't have electrical interference from itself, depending on the sensitivity can reduce enery cost and can reduce the amount of neurons required. [Answer] **More brains**. In humans, our brain is constantly sending signals to the legs saying "left, right, left" and every other muscle movement that's required. But, if you had a brain closer to the legs that was saying "Left, right, left", then your core brain need only say "Hey legs, start the left/right/left subroutine!" and then it can send any changes required like changes in direction when the eyes notice something, and just stop or starting to walk. This would be a very basic satellite brain. Same for other areas of the body that usually rely on signals from regular signals from the brain. Now, if your creature is so massive that waiting for a signal from the eyes to reach the primary brain, then sending a signal to the legs brain would be catestrophically slow, then it would be evolutionary advantageous to have secondary eyes near the legs, maybe even ears. Then, the legs could start working much more independently in terms of collision avoidance and path finding. The primary brain would more pass on a goal to the legs brain like "We want to go to this location that we've been to before", and the brain closer to the legs would take care of that. An example of this would be octopi, which have a core brain, and eight ganglia (bunch of nerve cell bodies linked by synapses, like a mini bran) that can transmit information to each other without involving the central brain, making the ganglia more efficient. [Answer] **Radio waves** Building on Monty Wild's idea of metal axons, is if the brains get big enough perhaps the axons begin to transition from being current bearing wires to radio oscillators. Instead of having one long axon the length of the brain you start having ones that act as dipoles. The brain would grow axons at different lengths (thus each axons signal would propagate at a different wavelength to reduce interference), then you would need a matching axon the other side of the brain and some handwaverium to turn the radio signal back into a useful neural impulse. [Answer] ## Farm the job out to Secondary brains There's been some mention of octopi, with their arms having secondary brains that have some degree of independent decision-making. But humans do this too! We have the concept of muscle-memory and reflexes because our nervous system has extensive local clusters of neurons much closer to the limbs. These clusters can be trained to perform complex actions based on simple inputs from the main brain. Some of these actions don't even need signals from the brain to be enacted. For example shoving away something extremely hot. The pain-signal from the hand reaches up to the local node, and is immediately responded to in-situ rather than going all the way up to the conscious brain and back. Similarly while I'm typing this, I'm not consciously aware of the process of typing. my hands "know" where all the appropriate keys are for a given letter. I'm not even thinking about individual letters, I'm thinking *Words* and my hands know how to move to write the letters and clusters of letters far faster than my eye can follow and even process what I'm doing. There are whole behaviours being farmed out to my secondary nerve-clusters which allow my brain, despite having a neural-lag of anywhere up to half a second, to perform high-speed and precise actions in a timely manner. **Back to what this means for Kaiju** I would expect to see more of that functionality, and likely a lot of it would be unconscious. A Kaiju would necessarily be a creature of instinct and reflex. If Godzilla stubs his toe, he isn't going to feel it for a few seconds but his leg still has to respond so he doesn't trip and fall. I would imagine a kaiju would necessarily need local "inner ear" style gyroscopic-senses closer to its legs so that its secondary-brain clusters aren't relying on the ones in its head. And then there's the challenge of coordinating leg-movements across hundreds of meters of body. Godzilla needs to have a fairly extensive neural-cluster in his pelvis which can handle 90% of the no-brain work for his legs. He needs to have quite extensive neural-tissue in his hands/arms so that when he touches something he shouldn't, he immediately lets go rather than continue to take damage for five or ten seconds. It may be that part of the supernatural resilience of kaiju is because they have such sluggish pain-response they simply don't react to having chunks blown out of them. [Answer] An octopus has lots of nerves in its arms/tentacles. So many, that they basically have brains of their own. Have you ever heard of Alien Arm Syndrome? It is like that, but intentional. A gigantic creature would probably have a series of minor brains that can react before communicating to the central brain. [Answer] Any non-instantaneous communication will still have neural lag, and it will be a problem at a sufficiently large size. Maybe there's a point where you're satisfied with your creatures' size and the neural lag doesn't have a huge impact (such is the case for us humans), but if you want to solve the problem for ANY size, you need instantaneous communication. Enter quantum entanglement. Quantum-entangled neurons could communicate with one another instantaneously, independent of distance (at least while in the same universe). This allows for galaxy-sized brains without beaking the laws of physics as we know them (except for allowing quantum entanglement of course), and it has the funny side-effect of not requiring physically connected neurons to form a brain. One human-neuron-sized neuron in every galaxy, all of them quantum entangled, could indeed form a brain (or a mind I guess). How would that mind communicate with its body is another question altogether, but perhaps each neuron has one body with a nervous system just like ours, or all cells are quantum-entangled and you don't have a galaxy-wide being but rather a galaxy is actually a single being. Lots of weird stuff can happen! ]

[Question] [ In order to win the World War one faction begins producing clone super soldiers. The war is eventually won, but now the government must do something with the Clones. They can't kill them because of some Civil Right activists. At the same time, they don't have the money to substain the gigantic Army of clones that they currently have. What can they do with the clones without angering the civil rights activist? Notes: * The people that populate this planet are biologically identical to humans. * The Clones are psychologically identical to humans. Their advantage over humans: super strength, quicker reflexes, above average intelligence. [Answer] ## Assuming You Thought This Through You should have considered this before cloning thousands of battle trained individuals with a propensity for violence. In which case, you would have engineered them to age at a much accelerated pace, meaning that each clone would only live for maybe a decade - long enough to win the war, but certainly not long enough for the survivors to pose a problem to your government. Alternatively, you could implement a genetic kill switch which would make them *highly susceptible* to a certain rare virus or bacteria. You could use that switch to kill them all whenever you wish, and plead innocence, ignorance, and grief at the terrible oversight of the genetic engineers - whom you could use as scapegoats. I recommend against this, however, as it is a design flaw which might be discovered/exploited by your enemies. ## Assuming You Didn't You are now stuck with tens of thousands of clone troopers who are currently lacking a purpose. ***What Not To Do*** Simply slipping the chain off the leash and allowing them to enter civilian life is the single, silliest thing you could attempt. They will never successfully integrate into society. We're talking about clone-soldiers here, not former civilians. These people will have never experienced the love of a parents, will not have grown up in your society, and would not have any experience in dealing with a civilian society. On the contrary, they are trained killers who have been not just raised, but *engineered* to kill people. We also have to take the many cases of PTSD among their ranks into consideration. Most people will (most likely) not feel safe having thousands upon thousands of *identical*, *potentially dangerous* individuals become a part of their communities. Especially smart ones (higher intelligence) who might replace them in a lot of lucrative positions. The most simple example I can give you is, in fact, Rambo (first movie): a highly trained, decorated war veteran, who - in his own words (paraphrased) - had been given enormous responsibility on the front, but was not trusted, and treated with disdain back home. He became a troubled man who lived on the edge of society, and was treated poorly by his fellow countrymen. Furthermore, flooding the workforce with so many individuals with similar skill sets will put entire industries out of business and possibly collapse your economy, or at the very least, shake it right up. Since the societal response to their arrival will most likely be negative, the only logical outcome is that these clone troopers will form their own groups on the edges of society. Traditionally these have become gangs, which, when lead by a smart individuals (which they all are), become a network of organized crime - identical mobsters; have fun dealing with them! There could even be enough of them - and they could become angry enough - to simply assault, and take over the government outright. ***A Possible Solution*** What you have to do at that point is find a new enemy to fight. You should, as the present conflict ends, already have one lined up, in fact, because there's nothing more dangerous than a few thousand bored soldiers - especially if some hippies get it in their heads that they should feel slighted in some way. At this point you're going to have to very carefully manage your troops. You should strategically set your own troops up in such a way that some of them should perish at the hands of the enemy, and no real blame can be laid at your feet. Furthermore, some clone casualties should quietly be allowed to die, rather than be saved. The trick here is: * Not having the press realize you are doing this * Not having the *clones* realize you are doing this * Not killing off so many of your own troops that you lose the conflict. What might happen in the final days of this new war is that non-clone soldiers might be brought in to "reinforce" the clones and thus cover up the fact that you've been killing so many of them, not to mention reinforce to the public that you didn't really need the clones in the first place - give the glory to the "regular" soldiers instead. The surviving clone soldiers - a much smaller group than what you started with - may now be used in other ways (such as what others have suggested), or even allowed to integrate into society (as best they can). The problem you should aim to avoid is having tens of thousands of them do this. (all at once, or at all) [Answer] Start a super-sports organization and have them compete in various sports. Hopefully, the increases in strength and speed will draw large enough crowds that the admissions will pay for the upkeep of the (former) super soldiers. There is a reason that current sports stars gain so much popularity: they do amazing things. Imagine athletes who are specifically bred to do amazing things. [Answer] This situation really isn't terribly complicated. In the scenario you have set up **the fact that your soldiers are "super" is irrelevant to how to proceed.** There is an abundance of historic documentation out there for what countries have done with militaries after major conflicts. --- The most obvious example would be **World War II**, it fits your volume of troops better than any other situation from history. At the end of World War II there were in the neighborhood of **12 MILLION** active duty US military personnel. The post war demobilization effort was named *Operation Magic Carpet* (which isn't really relevant I just really like the name) took a few years and reduced the active military force to just over 1.5 million. Most went back to lives in the civilian sector. The expectation of 'care' provided for veterans by the government was significantly less expansive at the time. --- **Concerns in other answers of soldiers messing up the economy and taking jobs is overblown.** If we continue to use the WWII United States as an example we can find that the US total population in 1946 was 141 million. This included the soldiers. Now in the case of the US those people were actually missing from the workforce and returned so there was no issue. Now if you add 10 million clones to the population (leaving a standing force of 2 million) you are talking about roughly 12 percent more people. While not insignificant it will still not flood the national stage too badly. When you consider that the economy also normally grows after a major conflict, finding jobs should not be too big a deal. And if I may extrapolate, your society is likely much farther in the future if you are able to create cloned soldiers, you would generally expect that the population would be larger as well. The larger a population gets the smaller the percentage that are in the military becomes, this reduces the impact of integrating these clones into society even further. To effectively integrate these soldiers you will need a few things. * Job training and placement. Many military roles have associated roles in the civilian world, if you can fix a tank you can fix a cadillac, a mechanic is a mechanic. Some specialties do not and those troops would need some job training assistance. * Societal integration. Your soldiers have likely experienced the world outside the military in some way. If they are modified humans they still need down time. Maybe they spent their down time on the town hitting bars and erm...dance houses. If that is not the case your military expectations are still going to translate in some ways to the expectations of your society at large. In my personal experience the military culture is a slightly constrained version of our standard culture. So while there is an adjustment to be made that is still true of troops coming back from war today. * Education and medical assistance. Get them educated and make sure they have access to both physical and mental health care. War leaves scars on the mind, super soldier or regular soldier. One additional complication I can see is resentment among the general populace. These soldiers will be better, faster, and smarter than the average worker, meaning odds are they will end up in high paying jobs...that could cause some...consternation. [Answer] Just some ideas, combine them or ignore them or whatever... **Cheap work force** When they don't have any education beyond what is necessary for fighting, use them as cheap manual labor. Surely you have a couple of bombed out cities to clean up and rebuild? Some dangerous territories to decontaminate? With the right spin on media reports, your Civil Rights activist will be entirely satisfied. --- **Put them on ice** Save them for the next world war. Will be a cost-benefit calculation, of course, how long keeping your 2 Million clones frozen is cheaper than constructing a new 2 Million clone army. If the Civil Rights activists complain, ask them where they were when the 2 Million clone army was commissioned. --- **Give them a one-time severance pay** Dismiss them from the standing army, hand every clone a thousand dollars to get started on their own life and then hope they won't mix up society too much. (PTSD? Since they are clones, they will all be the same gender, so what if they now all want to marry? No clue how to behave as a civilian?) --- **Reuse specialists** Some of them will inevitably be highly trained specialists with deep knowledge in Mathematics, Technology, and other important specialist areas. Your engineering companies will love you for providing them with such rare talent! --- **Space, the Last Frontier** Let them explore where no man has set foot before! They are out of your way, and also contribute a lot to science and society! [Answer] ## Some Assumptions For starters, I'm going to assume you made some good choices both before building the clone army and in your actual management of your soldiers. In particular, I'm going to assume that your clones have the following features: 1. They are clones of some good soldier who also represents your ideal man in other respects. Think Marvel Cinematic Universe Captain America. Honest, brave, loyal, with a natural sense of morality. What I'm going to suggest won't work with Jango Fett clones. 2. While you have improved the strength and intelligence of your clones, you haven't boosted their aggression "artificially". They will be more aggressive and violent than normal people because of their life experiences, not because of their biology. 3. Your training and propaganda has instilled in them a love (from a distance) for you country and culture. While they may have no actual idea how to live in a nice house with a picket fence, you have raised them to believe this is what they want. 4. You have commanded them reasonably and capably. If you treated ordinary soldiers as you treated these soldiers, they would not be mutinous. You have not treated them like battle droids. 5. You have encouraged a degree of individuality in your troops. The troops may all be identical, and their gear may all be identical, but each trooper still has "my rifle" and "my cot" and "my helmet". You want your troops to form a cohesive military unit, but you don't want them to form a collective organism like described in Plato's *Republic* or Halderman's *The Forever War*. 6. You have exposed them to many non-clones and non-combatants during their growth and training. Especially women. They need to have had female caregivers, teachers, and commanders. You do not want them to be like young spartan men who had no idea how to relate to half the population. If you haven't followed these best practices, the rest of this guide may not work for you, though some of the suggestions might work with some modifications. ## Discipline Throughout the following steps, you are going to have to keep better control of your troops than is typical with a victorious army. You have some advantages on your side: your troops have uniform upbringing that you have controlled, so you know that you don't have any career criminals or men with heritable mental illnesses in your ranks. On the other hand, your men have less than typical understanding of peaceful civilian life, so you cannot expect your society's norms to apply by default to your soldiers. Your discipline will have to be unusually firm. There's no dishonorable discharge for a super-soldier clone. He's either going home as a model citizen or not at all. Rape, murder, and desertion will be death penalty offenses. ## Occupation You don't want to bring all your clone soldiers home at once? Well, great news! You don't have to! To keep your soldiers from taking the food, jobs, and women of your homeland, there's really only one solution: your vanquished enemy. No, I don't mean brutal raiding and pillaging, I just mean that (like the US and USSR in Europe after the second world war), you're going to want to stick around in the previous enemy territory for some time. During this time, give your soldiers intensive training in aspects of ordinary life (ideally you have been doing this since birth). How to shop. How to throw a birthday party. How to sit quietly through an inane romantic comedy. How to change a diaper. Have psychologists document everything a typical man in your society does in his daily life, and compare it to what a typical clone does. Use education and field trips to help repair the deficits. Expose your troops to civilian life in the occupied territory first, so that if one of your soldiers freaks out at the variety of choices in the coffee aisle of a supermarket, it will not be on the home turf of your civilians. The defeated enemy is likely suffering a manpower shortage, so put your troops to work securing and rebuilding the occupied nation. This gives you great opportunities to teach your troops valuable civilian trades, without immediately upsetting your own economy. Give your troops plenty of opportunity to meet the locals in low-stress situations like helping a farmer remove unexploded bombs from his field. Historically, there has always been reluctance in conquered populations to marry the occupiers, but there has always been many thousands of cases of it happening. While your soldiers are clones and therefore more undesirable than a typical foreigner, they are young attractive men in a country with a shortage of young attractive men. This is where it's important that you have indoctrinated your soldiers with images of white picket fences rather than strip clubs. When TK421 meets a nice girl (maybe the daughter of the farmer he helped with that UXB), you need him to want to marry her and get a nice ranch house in Wyoming, not have a brief hookup. Of course you're not going to marry off anywhere near all of your clones this way, but it will help with your problem. ## Draw Down Accept that the occupation will last longer than militarily necessary, as you need it as a place to keep your clones. As you begin bringing your clones home, prioritize those who are married or have at least demonstrated ability to live successfully outside the barracks. You are going to need a ton of social services, especially for the first clones to arrive. You will need to build tons of cute little ranch houses with nice lawns and white picket fences (fortunately you have the manpower). You will need to have low-cost mortgages for veterans. You will need a GI bill to send your clones to college (to meet girls, if nothing else). Your civilian population will resent your soldiers, but each one is a 6'5" heavily-muscled killing machine with a friendly, respectful, and upbeat attitude who wants nothing more than a minivan, 2.5 kids, and to go bowling with his buddies on Wednesday nights. Your society will get used to him eventually. Some of your clones will never adapt. You are going to have a large army for a long time, so I hope you have the budget. But overall, a human being is a wonderfully multipurpose piece of equipment, just because you built him for war doesn't mean that's all he's good for. ## Economy So the bad news is over a number of years you're going to be inserting millions of new workers into your economy, and they may displace existing workers. The good news is you're introducing millions of new consumers to your economy, and each one is going to need a TV and a barbecue grill and a station wagon. If you allow it to, and you don't have other serious economic problems, this massive boost to your consumer economy can lead to a great period of growth. I wouldn't worry too much if I were you. ## Biology A lot of your coming "baby boom" is going to have (genetically) the same father. This will reduce your genetic diversity some, but shouldn't be terrible unless your clone army is really really big compared to your general population. Assuming you were smart in your selection of who to clone, having a lot of identical paternal genes won't be a big problem (you did make sure he isn't carrying any known genetic diseases, right?). Since you encouraged your troops to marry overseas, all the war brides may actually lead to a net increase in genetic diversity. Just resist the urge to make a bunch of clone women to offset your troops. And hey, now your super-soldier genes are getting spread throughout your population. Nobody will want to fight you! ## Politics Raise your clones to be political moderates, so that they are unlikely to form a single voting block. This will allow various political movements to appeal to them and keep the rest of the population from resenting their political influence. ## Final Thoughts Admittedly, this is a pretty rosy outlook. The key here is that good preparation avoids problems down the road. It is extremely important that you build your clone soldiers as "dual-use" technology. Normally the term "citizen-soldier" refers to citizens who can also become soldiers, you need to build your clones as soldier-citizens. [Answer] ## Occupation force You have won the war, and it is time to settle terms. With your non-clone based army, as soon as the people feels that the country is safe, you begin to be pressured by soldiers and civilians alike to end the war as soon as possible, to avoid the loss of more lives, so you are interested in reaching a fair settlement. But now there is no such pressure, so you can impose harsher terms to your enemies. Take a chunk of their territory; you already have made an investment in the troops you need to control it, so it is time to get a return of investment from taxing enemy civilians. If reaching to that settlement means that the war lasts one or two months more, it is not much an issue, since your casualties during that period help you solve your clone army problem. ## Start a new war A time honored ([Che Guevara in Bolivia](https://en.wikipedia.org/wiki/Che_Guevara#Bolivia), [Ifni War](https://en.wikipedia.org/wiki/Ifni_War)) way of disposing of armed elements that supported your bid to power and now might object to your policies is to send them to wage war against someone else. Preferibly, an "unofficial" war against a powerful enemy, in order that you are not dragged in when your agents (hopefully) are defeated. The worst possible outcome is that your troops win and you get to control a new territory. [Answer] Give half of them red shirts and the other half blue shirts. The problem will solve itself. [Answer] ## Peacekeeping Forces Fighting a World War is a serious endeavor, and ending one is not a simple process. You are not going to be able to simply retire your entire army once the fighting is over no matter if they are clones are mundane soldiers. You now have a (presumably) large number of foreign countries that have just lost a war, and are going to be feeling bitter and resentful of that fact. Stationing your clone troops throughout the defeated countries will let you use them as peacekeeping forces to prevent that resent from turning violent. Or you could use them as "peacekeeping forces" and have them act more as an occupying army, keeping the defeated populaces in line more forcefully. Regardless of how they get used you should be charging the countries where they are stationed fees for the service, essentially making them pay for your soldiers. Remember, those countries have just lost a World War, and according to our planet's history that means that they are going to have to suffer through some sanctions put in place by the victors. ## The Legion of One Another alternative is to use all or part of this new clone army as a mercenary group. Think of something along the lines of the French Foreign Legion. You have a large number of trained soldiers, presumably loyal to their causes, and designed to be stronger, faster, and smarter than regular humans. They would be the obvious choice for anyone in the market for hired soldiers. This would, again, allow you to foist the cost of the army off onto others. The War may be over, but there is a very good chance that during the conflicts different countries or groups on both sides will have come into contact and formed some grudges. Or could be ready to settle existing grudges in the chaotic aftermath of the main fighting. Either way, as long as those groups have money and need soldiers your clone mercenaries will have plenty of opportunity to be useful without being a burden on your citizens. ## The Best There is at What They Do Given the cloned soldiers enhanced abilities, there are a handful of very specialized public- and private-sector jobs that they would be ideally suited to fill. Chances are you will have more clones than these roles, but they should still be considered. Private security forces are the most obvious job, again assuming that an increased sense of loyalty is included with the enhanced strength and intelligence. Bodyguards that are stronger and faster than normal, plus with known military training, would be in perfect for various high ranking public officials or private individuals. Same with security officers at important locations, defense research centers and the like. There may be some public outcry at replacing the general police force with military trained cloned supersoldiers, but you may be able to convince John Q Public that using the clones for SWAT teams or something similar is better than the alternative. ## Mix and Match Chances are that no single one of these suggestions would be a good, long-term fix for what to do with the clone army. But if you took all of those soldiers and broke them up into a mixture of the three, plus whatever else you can come up with, then you should be able to get most of the clones in a place where they are being useful, without being a huge sink on your own resources. [Answer] Militaries spend a surprising amount of time doing *non military* tasks. Depending on the context? *Private armed security* - or to take a page from the singapore government *Auxillary police*. Basically well armed, *extremely disciplined* security guards for banks and installations that need extra security - oil refineries, military bases and so on. Keep em on as reservists, and give them refresher training as needed. As an extension of that idea - it might be worth looking at the gurkas, who while citizens of one country, have served with distinction and honour in both the militaries of the united kingdom and india as well as an elite wing of the singapore police force. They might be allowed to serve, as a unit in allied militaries, possibly in places that were defeated but are nor friendly. *Peace Corps*. You've won the war, but you need to keep the peace. Have these guys build schools, and other infrascture. Have them assist in periods of humanitarian disaster (Which modern militaries are actually *really good at*). There's also something to be said for big menacing *nice* guys to convince the local riff raff that trying to snatch whatever they can is bad. *Space exploration* You have a large, well trained group of folk, who have many of the skills needed to survive in a hostile environment. Depending on your universe, they might be the perfect folk to act as interplanetary or interstellar scouts and the first wave of colonists - this might also deal with the resentment - since these folks might been as heros instead and in a sense gets them out of the way. [Answer] The obvious answer to me is to put them to work. You say that the government doesn't have the money to sustain the very large population of new citizens, but the question there is why? If it is due to lack of food, portion off some of the clones to food development. If it is lack of housing, then you teach some of them to build homes and such. Pretty much the only real issue that might be truly limiting would be space, but considering they managed to house the clones during the war, plus there is no doubt a decent number of casualties from the war, then there should be enough space for them to live. This might entail some social changes such as group housing or building more vertically, but it should still be able to be done. By having the clones trained and doing the work to support themselves, the burden is eased on the government to figure it all out. Plus you get the bonus of keeping all of these likely trained killers under watch and busy doing something productive rather than deciding to go off and conquer a land area of their own. [Answer] As AndreiROM pointed out, you can't really afford to let them loose on society, since they probably don't have the social background to handle non-war life. They do have a certain set of skills though that could be useful to society. They are disciplined, and used to hard work, so put that to use. First, turn the swords to plowshares. Start something like a farm or [kibbutz](https://en.wikipedia.org/wiki/Kibbutz) where they would grow their own food and try to be self sufficient. If there is any excess it can be sold to help pay for necessities. Provide training, especially in things like law enforcement, where their training as a soldier would be useful, but let them have other choices. Also provide mental health services to work through any war time mental scarring. Loan some out to help protect people who are doing humanitarian aid in war torn areas. This will let them use their training, and would also give them opportunities to be around civilians and learn how to interact with people. These could be short shifts, with a couple months protecting a [school for girls in Pakistan](http://www.ibtimes.co.uk/peshawar-school-massacre-girl-hating-taliban-attack-1000-un-islamic-pakistan-schools-last-1479821) then back to the farm for some R&R, while the next shift relieves them. Bring groups in to work alongside them on the farm, both so that they can learn to be around civilians, but also so that civilians can learn to be around them. Acceptance is a two way street. Given enough time they will learn how to integrate, and then you can start phase 3 where some will be allowed to choose if they want to move off the farm. [Answer] ## **Core of Engineers Infrastructure Program** Keep them in the military, but retrain them to be army engineers. Keep rank, orders, barracks, and other military routines nearly identical. Then put them to work in major infrastructure projects. Psychologically paint the work as a nationalistic and patriotic challenge(or whatever rationale was used in their military training - religion, democracy, communism whatever). It should be reminiscent of battle, but without the danger, killing or anxiety. Rework the conflict into constructive struggle, filling that psychological gap with work, challenge and purpose so the ghosts of battle don't fill it. Treat it like therapy. Focus on major public infrastructure, dams, roads, railways, hyperloops, bridges, spaceports, fusion reactors and the like. These things are typically too big to be financed by the private sector, and so won't compete for jobs or paying clients. In fact, it will provide a huge boost to your economy. Granted, it will be very, very expensive(though not as expensive as a war), but the immediate economic boost will offset it somewhat, and the long term payoff should put you back in the black in a decade or two. Meanwhile, your clones are focused, trained and busy. People are enjoying power, transportation, and growth. Your activists are happy because we are making roads not war(Insert catchy flower power slogan here. Hey, it's true!), and the new lifestyle is legitimately healthier and recuperative for the clones. The only major problem is that if you are close to bankruptcy, the scale of these projects may be too much for you to finance. [Answer] Some old movies come to mind, you might watch Demolition Man (rewiring to normal life), Universal Soldier (problem with mindless mercenaries) and Rambo (problems resocializing). Best so far would be reintegration in an own community outside of civilization (like tibetian monks) and letting them out for mercenary services. Maybe Judge Dreed like police service. You can also "figure out what they want" and let them lead those lifes. [Answer] It is a very common fallacy that there is only so much work to do, and that any additional workers only hurt. The soldiers-now-civilians need food, shelter, and clothing, so by their existence they create the need for more work to be done. The soldiers have the capacity for ordinary civilian work. Anyone who has worn the uniform of any military service can tell you that the bulk of any soldier's duty hours, when not in actual combat operations, are consumed by duties that are similar (if not identical) to work done in the civilian sector. There are ditches to dig, papers to push, machinery to maintain, etc. The Army doesn't care how fearless you are or how well you can shoot. There are 1,001 peacetime functions that soldiers do every day, and if you can't do them, the Army most definitely does not have a uniform in your size. So it's an issue of matching ex-soldiers to jobs for which they are suited, and providing education for the rest to fill openings in the economy of your fictitious world; unless you have wished away the laws of economics, your fictional world has many, many labor positions for which no suitable candidate has applied. It is true that some of your clones have PTSD issues that preclude an immediate return to civilian life. However, these are in the minority (or else American society would have self-destructed in 1946); if you have the resources to field all of those guys, you have the resources to provide treatment for the minority who need it. [Answer] You have won the world war, so the world is yours. Use your clone soldiers as a security force in all countries. They are the best in doing their kind of work, so give that work only to them. Bring back your original human soldier to the country and ask them to rebuild the nation. This will result in financial growth for the country that you can use for maintenance of the clone soldiers. It will take some time but you will recover quickly from the war and that is the most important goal at that time. Do not disturb society by including them in the society. [Answer] One situation you need to take into account is how the Civil Rights Groups felt about the creation of clone soldiers just for the purpose of fighting a war. If the soldiers were created to advance in age quickly, what would those groups have said about the age advancement? And then come care of cloned troops. LEt's say that the creation passes the civil rights groups, what kind of care do you give them during the war? Were they treated like regular folks who are in the war? Are there any regular people in the fighting ranks? Do the clones have a rank system allowed to them? Now for after the war, are there more clones being created, or did they cancel the program once the war was over? Or can the program be used for other clone types (labor for instance)? Perhaps what made the clones fighters (mind-manipulation) could be used to reprogram them to do other jobs. A few questions to think about before wondering what to do wtih them after the war. [Answer] ***The government will do whatever the clone soldiers want them to do because the clone soldiers will be the government.*** As Mao observed in one his breaks from sociopathic mass murder, "political power flows from the barrel of a gun." Governments are at their heart merely instruments for collective violence. The most basic government is a general/warlord and his victorious army. In all times and places, the military decides the form and nature of the government. I consider the idea of the malicious creation of super-soldiers even on the small scale in "secret" experiments to be one of the stupidist tropes in Science Fiction. You don't give off scale military effectiveness to someone you don't trust and don't deal fairly with because they will kill you. There are many historical precedents for the scenario you envision. The two most famous would be Malmuks of Egypt and the Janissari of the Ottoman Empire. In both cases, rulers created armies of foreigners, usually starting with slaves. The Malmuks, were a mishmash of young men of many different subcultures and non-muslims faiths swept up in the Islamic conquest of Christian north Africa and their non-Christian surrounds. With their homes destroyed and the under foreign rule, their families dead, enslaved or scattered, the opportunities offered by a life of slave soldier didn't seem so bad. At least you got to eat. The Janissary where Christian children from the area of modern Romania, Bulgarian and Balkans taken around the ages of 6-9 as a mandatory tax tithe (hand over your son or we burn your village down.) Christians were taken, as enslaving fellow muslims, well true muslims often defined on the fly, is forbidden by the Koran and the Ottomans didn't want the hassle. When they grew to adulthood they could convert to Islam and "volunteer" to continue serving. But as they had no memory of their families or how to find them again, they had little choice but stay. Telling, the symbol of the Janissary was a large wooden spoon worn on the front of their headgear, a symbol of the Sultan's pledge they would never go hungry. (Food was the major concern of humanity until the Corporate-Industrial-Fossil-Fuel Age.) The Sultans turned to slave armies first as internal security troops, as a force wholly dependent and loyal to the Sultans and not some noble or clan as were the rest of military. If some noble rebelled, the slave armies put it down. (Its the same reason they relied on eunuchs. Family pull was so strong only someone without testicles and a hope for a descendants could be trusted. Eunuch taken as slave from far away where even better) Since the slave armies lacked any families or birth status, the only means of promoting them lay in judging merit. Very quickly the officers of slave armies became comprised of individuals who rose by proving themselves in battle. They soon became the most elite units of their respective polities. As time passed the Sultan became more and more dependent on the elite slave armies. Things worked fine for a century or so but eventually there was some instability in the realm and the slave armies looked around and thought, hey, we don't have to take orders anymore. In the case of he Malmuks, they merely replaced the ruling class of Egypt and survived until Napoleon crushed them. The Janissary kept the superficial appearance of the Sultan being in charge but were in fact a Praetorian guard who selected who could and could not be Sultan. In both cases, as they came to power, began to marry and form clans, they lost merit promotion and with it military effectiveness. The moral is that its impossible to politically control highly effective soldiers if they don't want to be controlled since they themselves form the basis of coercive political power of the state. The form of government is dictated by dispersion of military force in a society. If most of the population is disarmed and only a small elite allowed weapons and training, you have an oppressive, authoritarian regime. If the majority of the population is armed and trained, you get some form of democracy e.g. Athens, Roman Republic, Britain and the U.S. There are no historical examples of any degree of democracy in societies where the majority of the population is disarmed and conversely, no examples of authoritarian regimes where the majority of the population is armed. So, the real question in your scenario is not what the "government" will do with the clone army but what the clone army will with the government. I would also point out that any society which cannot muster enough internal cohesion and form enough political consensus to muster an army from its own population, is dead anyway. You can see this in history in Carthage, the late Roman empire and Byzantium. Once they could no longer raise a military from their own population, they spiraled down hill. All had plenty of population, they just did not have the internal cohesion and trust to build a military. So, the fact that your society resorted to a clone army, unless faced with an enemy using super soldiers themselves, would indicate a disintegrating polity. Even if the society was willing and capable of defending itself without the clone super-soldiers, the clones will still be the de facto rulers of the society once the war ends. They might take over like the Mamaluks, or they might leave the illusion that the old regime is still intact like the Janissary but they will still rule. You might want to investigate the actual scientific evidence about what makes a good soldier. To much of what we think we know comes from smug, morally self-rightous pseudo-intellectuals who bloviate with based on no empirical evidence. In the case of industrial warfare, strength is largely irrelevant but low term physical endurance and ability to function with less sleep become more important. Intelligence might be a bonus depending on what you mean by "intelligence." Visual spatial skills are the most important for all types of soldiers from ground pounders to pilots to generals. The most important qualities for soldiers are emotional, not cognitive. You'd want to make them calm and hard to excite so they keep aware and thinking as everything explodes around them. Also, give them a touch a ADD to they will be more aware of changes in their environment and not get fixated on one aspect of it. The most important quality for military effectiveness is unit cohesion i.e. how strongly individuals bond with and trust other soldiers both those immediately around and the greater organization. Highly cohesive militaries have defeated much larger otherwise equivalent militaries repeatedly throughout history. The second most important quality is a belief in a higher good, something the soldier will love enough to willing die (and kill for.) Both these attributes require that the soldiers have high levels of empathy, something counter-intutive but obvious once you think of it. You could create "super-soldiers" merely by making clones highly empathetic, cooperative, trusting and then indoctrinate them with an ideal to protect. They would be more effective than ordinary people even with the same IQ and strength. The problem you might have after the war would be when the clones encounter the real world and find out that the rest of society is cynical about the clones ideals and that far to many civilians lack empathy, won't cooperate and don't trust each other. The clones might be shocked to be lied to or cheated by individuals that they consider part of their group instead of enemy. The clones might well decide to take over in order to enforce their ideals and ernest behaviors on their imperfect natural brethren. Regardless, the super-soldiers will decide the outcome and no one else. ]

[Question] [ I am inspired by some people who apparently believe chocolate milk comes from brown cows. I know that for sweet, delicious chocolate to come into existence, we need to do things to cocoa. Ferment it, grind it, mix it, bake it. That's boring. Besides, as cheap as human labour comes, animals don't unionize. Would it be possible for us to engineer a creature (preferably an animal) that produces chocolate from its teats (or other parts)? Conditions: 1. I am willing to accept all kinds of animals, i.e.: if aphids are a better choice for the task, so be it. 2. Due to the above, the final product doesn't have to be milk chocolate. The goal is met when we have the raw, bitter stuff. 3. If chocolate is not possible, then cocoa butter, cocoa solids or a mix of both are acceptable. [Answer] Ok, so this seems pretty simple. There are three basic things that happen to turn cocoa beans into something reasonably approximating chocolate. **1: Fermentation** Counterintuitively, the first step in turning Cocoa beans into chocolate is getting RID of the sugars that are already there, allowing the natural yeasts and micro-organisms to turn the sugars in a ripe bean into alcohol, and then acetic acid. This is critical in generating the aromas and flavors that we associate with chocolate. Fermentation is also a pretty common process in digestion though, so it's totally plausible that an organism could eat the beans and, in the process of digesting them, complete the fermentation. **2: Roasting** The roasting does a [few things](https://chocolatealchemy.com/cocoa-bean-roasting/). It removes the husks from the actual choco-meat, it sterilizes the choco-meat, and it does some more chemstry to improve the flavor. In the case of an animal, the first of those items can be handled by chewing, the second is... probably just not going to happen, and the third can be managed by the appropriate acidic environment in the digestive system. **3: Addition of sugar** The easiest way to manage this is for our animal to supplement its diet of cocoa beans with other stuff that has lots of sugar. Fruits, for example, sugar cane depending on location, stuff like that. All of that having been said, there's a clear answer right here. **BEES!** Big, freaking, cretaceous sized monster bees. They do the honey thing, but ALSO like to have a gnosh on cocoa beans. The two things get mixed together and then vomited up into giant beehives just like modern bees do honey, only more choco-tastic. [Answer] You might want to have a look at this patent about artificial chocolate flavor <https://patents.google.com/patent/US2835590A/en> If it is possible to produce the flavor in the laboratory it should be possible to maybe create certain bacteria to do the job for you. You might however need more than one kind and they would still need to grow in big and controlled storages. I’m not a bio engineer but maybe someone else can give a more profound answer to my claim. Once you have the flavor you probably can produce something similar in taste to natural chocolate. [Answer] Since it is already the case that goats have been [modified to produce spider silk in their milk](https://en.wikipedia.org/wiki/BioSteel), it would not be a big stretch to have them make the chemical components of chocolate. However, since there are between 300 and 500 different [chemicals in chocolate](https://www.worldofchemicals.com/113/chemistry-articles/chemistry-behind-the-sweet-lure-of-chocolate.html) it might be a lot easier just to get chocolate from the plants we already do. Probably to get non-lethal and pleasant tasting chocolate would take a lot of "nudging, poking, probing, twiddling, fiddling, and messing around." [Answer] ## *You don't want to use animals, use a plant instead.* Considering all the ingredients are biological products there is no reason you can't engineer it however you want given enough time and effort. Although it might be easier to just engineer the cacao plant considering all the ingredients are already present. Plants are good choice becasue they are energetically easy to work with and already have most of the right pathways. Animals are rarely a good choice for plant based genes, the pathways used by animals and plants are often too different for compatibility. There are a couple of ways to approach it. Fruit, dark chocolate fruit sounds amazing. You need to engineer them to produce it in the fruit flesh instead of just the seeds, producing fewer alkaloids will help as well that is where the bitterness comes from. Fermentation is just the breakdown of existing biochemicals which could also be engineered its a fairly common biological process. Seeds, this is the easiest but also the least like what you want. This is similar to engineering it into the fruit flesh. The positive of doing it this way is you get something much closer to the texture of chocolate since there is no need for fiber. The down side is you will likely end up with a sterile product so you have the same problems bananas have, AKA genetic uniformity. You also still have significant processing required. **Chocolate avocado.** This is the most engineering intensive but will also give the best result. The avocado is already a uniquely protein and fat rich fruit. You are engineering it to produce a different set of proteins and fats. You can get a texture similar to chocolate without much processing possibly none. Done properly you might even get the giant seed in the center tp produce something similar to contemporary chocolate, which is good for your bakers and cocoa drinkers. Of course seedless avocado exist, so you could have basically solif chocolate inside a a skin. [](https://i.stack.imgur.com/JRciK.jpg) [](https://i.stack.imgur.com/Sc3Zn.jpg) [Answer] Chocolate contains theobromine, an alchaloid like caffeine, cocaine etc. All these alchaloid toxins are used by the plants as defense against attackers (though we humans get usually oddly addicted to those which do not kills us immediately). Which animals already produce toxins? Some tetraodontiformes fishes, several spiders, several snakes, several insects. You would need to add more to just theobromine, but you have already the reactor. Insects, spiders and snakes would have little individual production, but the first two can compensate with large numbers per unit surface. Plus spiders could produce chocolate in convenient filaments, instead of their silk. The tetraodontiformes fishes could have their whole body made of chocolate, similarly to how its bowels and skin are already packed with tetrodotoxin. [Answer] I think you should check out <https://en.wikipedia.org/wiki/Kopi_luwak>. It is a kind of coffee. A cat-like animal - the civet - eats the coffee beans and transforms the raw product into one of the world's most expensive coffee blends. You are drinking poop (and you paid a lot of money to drink poop). IF you fed chocolate beans to a civet I would not eat its poop, but someone else would and they would probably pay you a bunch of money for it. [Answer] # Yes, the cocoa plant. You said in a comment you'd accept plants. So, this clearly is the most obvious answer. ]

[Question] [ What would be necessary in order for bubbles to rain down from the sky, whether they are actually soap or something else? Would it even be possible? Aside from a bunch of little kids (which would be awesome to be honest) would there be a natural phenomenon similar to this? [Answer] Let's assume for a moment that there are [bacteria living in clouds](https://www.livescience.com/2333-earth-clouds-alive-bacteria.html). These have to feed on something, but nutrition in clouds is scarce. The chances of collecting molecules with nutritional value increase with the surface area that can be used to collect them. Sometime during the endless evolution some bacteria managed to excrete a slimy substance that can trap gas and form a bubble. Additionally, the bacteria excrete a gas as metabolic product which now is trapped inside the bubble, increasing the surface area that catches nutritional molecules. Due to global warming and rare weather conditions that blow nutritious Sahara dust into those clouds, the bacteria reproduce faster than usual, weighting down their bubbles until they rain down to earth in a spectacle dazzling thousands of people. --- Alternate version on an alternate planet (thanks to EngrStudent): > > I think that in a methane and nitrogen rich atmosphere, in a space with lots of grains of sand meteors made of iron or nickel, you could superheat methane in the presence of nitrogen and a catalyst, and make more complex compounds. Aerial bacteria could then convert those to "soap" as a protection, and as they emit metabolite gas, make bubbles. > > > [Answer] **Eucalyptus trees can form bubbles when it rains** Combine a eucalyptus grove with rain and a high wind that blows the bubbles away as soon as they form and you have a rain of bubbles somewhere down the line. [Video - Why do trees blow bubbles?](https://youtu.be/rZg64CobDeQ?t=29) [Answer] ## Decyl glucoside One fun idea would be a new generation of planes. **Explanation** : In order to create bubbles in the sky the presence of surfactant molecules are needed. One natural surfactant molecule used in shampoo is called "Decyl glucoside". It is obtained by the reaction of glucose from corn starch with the fatty alcohol decanol which is derived from coconut ([wikipedia](https://en.wikipedia.org/wiki/Decyl_glucoside)). [](https://i.stack.imgur.com/Okckl.png) This molecule is an alcohol with a "long" carbonated chain which is not so far from the regular ethanol which can be used as fuel. Now imagine a new generation of little planes using this molecule as fuel : 100% natural and environmentally friendly. The only thing engineers didn't manage to do was to obtain a complete combustion of the fuel so a small fraction of these molecules are just released in the air. The unexpected effect has been to see the apparition of rains composed of... Bubbles ! But this is a little cost to pay for an environmentally friendly plane so this technology is now very popular and it rains bubbles on a daily basis. [Answer] Raining bubbles is somewhat similar to sea foam. Both require the water (or similar substance) to be stretched and agitated in such a way in which to encircle and trap air. Simply put, our rain here on earth cannot take the form of bubbles because they are so dense and do not have forces placed upon them that would shape them into disks and eventually bubbles. By having very specific air patterns, such as multiple focused streams of air rising upwards from the ground, it is possible to have individual raindrops spread apart and become "injected" with air, forming them into bubbles. However, air streams such as these do not occur naturally on earth, so you would have to create a reasoning for these air currents to exist in the first place, be it vents, or organisms, or what have you. Unfortunately, this method is not likely to catch every single rain drop, so a rainstorm would likely contain a mixture of droplets and bubbles. [Answer] One possible condition to have bubble rain would be a large differential pressure in one gas across the height of the atmosphere. Let's say, for the sake of this question, that CO2 has a pressure of 1 bar above 6000 m height, and the usual value we are used to below that height, with the overall atmospheric pressure being 1 bar (let's ignore for the moment the change of pressure with height). When the rain drop forms it will be saturated in CO2, but upon descending the excess gas will try to get out to accommodate for the different pressure. This will form an air pocket into the drop, generating at all the effects a bubble: a liquid shell around a pocket of gas. [Answer] 1) Wind formations that lift from the ocean and bring particulate and other light matter into clouds over the land. 2) Regular lightening strikes into the ocean causing: * Dead carcasses of very fatty sealife. * Lye formation (also chlorine formation, but assume the different weights work out such that the wind moves lye and chlorine to different locations). 3) Many birds that gorge on the fatty carcasses and release their excrement into the air where it is then lofted by the winds and brought inland (winds not too strong for the birds to be caught up in). 4) Lye + water vapor + fatty acids = soap. 5) Soap (it's gel at this stage) + more water = diluted liquid soap. 6) Liquid soap + gentle force of forming raindrops + gentle winds = bubbles. [Answer] Actually not sure whether this would work, but think of a planet with a very low gravity. This would automatically lead to the water forming more or less sphere("bubble") like shapes. If you still need a big surface, make your planet have no core. Or, even better, have a *Lagrange point* at the surface due to another planet - eg the two planets are orbiting each other, such as [Pluto and Eris](https://www.space.com/28379-eris-dwarf-planet.html), in such a constellation that objects on the surface are *almost* equally dragged towards both of them. However, one planet still has to drag the stronger, else the bubbles would float in air, but not come down... With such a low impact of gravity, air would be mainly influencing your bubbles. [Example - Water bubble in space, NASA](https://www.nasa.gov/sites/default/files/images/723520main_8413732347_ceb0cc9a40_o-full_full.jpg) --- A different attempt would be magnetic fields. We all know that electromagnetical forces(Couloumb-Force) are far stronger than Gravity. So they can influence the water in such a matter that it forms bubbles. [Example - balloon next to water](https://www.thenakedscientists.com/get-naked/experiments/bending-water-static-attraction) And now think of some particles in the air that are charged with a high positive or negative charge. They would get a water bubble around them... ]

[Question] [ So I've got these large crab-like creatures living on the Abyssal Plain under the ocean (way way down 9800-20,000 feet down). At this depth the main food source is the marine snow, "a slow drift of mucus, fecal pellets, and body parts—that sinks down from the surface waters". And, of course, your neighbors. Let's call our creatures Crabites for now, because that's their name, and besides, it's fun to say. Crabites. The Crabites have evolved intelligence and would like to build a civilization. The problem I'm seeing for them is that for civilization you need **surplus**, which is mighty thin down there on the Abyssal Plain. The marine snow is not constant; there is a constant rate, but there are huge irregular windfalls (good article: <http://www.mbari.org/feast-and-famine-on-the-abyssal-plain/> ). I'm planning to have their lives revolve around gathering and accumulating the regular snowfall, and then snap into frenzied action to gather and hoard as much of the windfalls as possible. Problem is ... I'm not sure this is enough. I'd like to have some kind of agriculture because of its insane ROI (100 kernels of wheat from one seed, minus slippage). But what can they grow? The best I can think of is shallow-sea hunting, where they float themselves up to the rich zones and kill everything in sight, bringing it down. But -- and here's the main question -- **is there anything down that far which can substitute for agriculture?** **Update** ... I'm seeing some great ideas in answers, in particular harvesting from hydrothermal vents. I am thinking this is promising, as are methane "cold seeps" (<https://en.wikipedia.org/wiki/Cold_seep>) which are less extreme, can be found in shallower waters, and can support chemotrophic-based ecosystems. I may have to bump up my planet's volcanism and overall methane production... [Answer] Oh boy, that gives me a *nasty* idea... **Who says it's the ground *below* them which they farm?** So, these creatures live mainly off "huge irregular windfalls" that basically happen when for some reason there's a lot of dead biomass coming down from the surface... What if they found a way to *engineer* those "windfalls"? The article you link to mentions algae blooms as the cause of the windfalls they observed. Well, algae bloom when they get more nutrients than normal, mainly phosphates. So if your Crabites somehow find a way to propel large amounts of phosphates towards the surface, they could do some pretty productive farming! Maybe this is something that occasionally happens naturally in a way they can observe, understand and later influence, e.g. hot water vents creating an updraft in the middle of a phosphate deposit on the seafloor. Or, in a rather less pastoral and more terrifying vein: the Crabites could also release toxins that float up and cause a large-scale dieoff of surface life in an area... [Answer] I see three main solutions to this problem. **1) Hydrothermal vents** [Hydrothermal vents](https://en.wikipedia.org/wiki/Hydrothermal_vent) are locations of enormous biodiversity relative to the rest of the deep sea. They're places where [chemosynthesis](https://en.wikipedia.org/wiki/Chemosynthesis) can substitute for photosynthesis and allow the conversion of chemical and heat energy into sugars. This is where most of the life in the deep sea has decided to live, so they may have a point about its likely habitability. However, this does limit your Crabites to the areas near [mid-ocean ridges](https://en.wikipedia.org/wiki/Mid-ocean_ridge) and they wouldn't be able to survive on the abyssal plain. **2) Living off the detritus from above** This seems to be the most like what you're looking for- a rain of energy from above that sustains life. Unfortunately, it's a *very* small amount of energy that actually reaches the seafloor- of the 100 petagrams of carbon that pass through the surface ocean each year, 0.1% of this actually reaches the seafloor. In the below diagram, we're interested in the Particulate Organic Carbon (POC) because that's the carbon that's still in edible form. [](https://i.stack.imgur.com/UohCJ.png) To put this number in perspective, that's approximately equivalent to one tree every 50 square kilometers, or the grass in the American West growing at about 1% of its normal capacity. There's a reason these areas are referred to as deserts! I envision this scenario less like a pastoral scene with a happy rancher surrounded by grass/trees and more like a Mad Max style wasteland, with intense competition for the moments when food is actually found. **3) Abandon the agriculture and return to hunter ways** This is probably the most realistic scenario. Your Crabites would be able to survive most easily by hunting deep-sea pelagic fish. These fish undergo a [daily vertical migration](https://en.wikipedia.org/wiki/Diel_vertical_migration) from the surface to about 1500m, which is the largest migration on Earth by biomass. The fish do this to escape predation at the surface during the day, when predators could easily see them and they'd be eaten. Your Crabites, on the other hand, would be doing the opposite- ascending from the depths each day to meet the fish as they descend, hunting vigorously during the daytime, perhaps with the help of some [electroreception](https://en.wikipedia.org/wiki/Electroreception) or "night-vision" capabilities, and descending back to the depths during the night to do whatever Crabites do when they aren't hunting. The good news with this strategy is that fish are fairly easy to find in the deep sea- at times, they're so dense they look like the seafloor via sonar, which gave them the name of the [deep scattering layer](https://en.wikipedia.org/wiki/Deep_scattering_layer). [Answer] I would suggest **animal husbandry** as a substitute to agriculture. Plants, of course, don't grow down in the deep, though it might be possible to farm bacteria or other microorganisms. What's most interesting, and I didn't know this before, is that crabs of the abyssal plains are *already engaging* in something very like husbandry! It turns out that crabs already use sea pigs as [crab nurseries](https://oceanbites.org/when-pigs-get-crabs/). Your sentient crabs, I think, could certainly be herding sea pigs and using them not only as nurseries, but also as surplus food source. I can easily imagine a semi-nomadic civilisation of wandering tribes of Crabites managing their vast flocks of sea pigs! [Answer] They live under a Whale Graveyard, similar to an [Elephant Graveyard](https://en.wikipedia.org/wiki/Elephants%27_graveyard). Some whale-like aliens in the surface always go to die of old age at the same spot. Their corpses fall rather than float. The whale population blooms for some reason, so suddenly the Crabites have plenty of food. Optional: feasts of food descending from above irregularly has quite an effect on religion. [Answer] If the energy flow is 1/nth that of the prairie, then they live at 1/nth the rate. In that sense problem solved. The organic snow is constant, but accumulates steadily. So there could be periodic harvests. This constant fall would encourage extreme territoriality. Some areas would be more valuable than others. Places like the equator where there is no sharp upwelling would be even more deserty. Areas where there were algae blooms on uprising currents would have a 'food plume' descending down current from them. A huge win would be if they could create such plumes. If they could establish communication with us surface dwellers, then they could help us make OTEC engines. <https://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion> This lifts quantities of nutrient rich abyssal water to the surface where it would foster a surface bloom. The economics of OTEC are marginal -- you're running a heat engine on about a 20 degree thermal gradient, so at best you are going to get 20/270 or about 6-7% thermal energy. A cubic meter of seawater with a 20 C temp diff has 20 kCal potentially or about 80 kJ. If you can get 1/4 of this out net, then 20 kJ/m3 or 180 m3 of water moved per kWh. This requires really big pipes to be efficient. [Answer] They don't need more energy to have a surplus if they can be more efficient. The pre-civilized Crabites compete with hundreds of other species in dozens of tribes. If a group dedicated itself to monopolizing a patch they might be able to harvest it with less energy. Instead of scouring the patch ready to defend against attackers living in the area, a small well armed response force protects all the dedicated harvesters. If feast and famine is the norm there is an advantage to developing food preservation and granaries. This incentivises cities to defend and live off those stockpiles. [Answer] **Abyssal Agriculture** Can be tough without the sun but there's one alternative: *Microbies* can thrive in that thermal vents sustained by the minerals and heat it provides. Maybe the crabies builds their "huts" around a vent and use it's heat and harvest it's microorganism in addition to hunting and collecting. Maybe there are vast thermal vents fields and they can tend the "crops" developing thecniques to best harvest ang grow colonies of microbies they can consume. For example they can build "parachute" like structures anchored in the sea floor over the vents to better use the expeled materials from it and grow colonies of microorganims in its canvas. Once the canvas is "mature" (covered with enough microorganism colonies) they can harvest it. They can also resort in some kind of bivalve farms, much like we do today. And don't forget "cattle", large fish grazing in plancton. [Answer] **Murder pits.** Food comes from above and is gathered on the bottom - but is that *deep enough*? On a universally flat *Abyssal Plain*, food is distributed more or less equally on the ocean bed, thereby making it necessary for the Crabites to go and *hunt* for their food. However, by teaming up the Crabites can dig *deeper*, creating larger pits with gradually increasing slopes on each side, in which the food naturally gathers. Right above it, the Crabites create a toxic cloud which kills everything several meters above it. In order to do this, the Crabites secrete a saliva rich in certain bacteria that produce methane gas when exposed to decaying corpses in an oxygen-poor environment (i.e., the process of anaerobic digestion). Basically, they *spit* digestive bacteria into the pit. Once the pit is sufficiently filled with corpses, body parts and other "ocean snow", they proceed to consume it. Then, they lie in wait until the next "batch" is finished... ]

[Question] [ In many depictions of dragon slaying, we often see people fighting dragons toe to toe with melee weapons, like swords or axes. But in real life, we kill actual gigantic animals, like elephants or buffaloes, using ranged weapons like throwing spears, bow and arrows, or firearms. Even when not hunting directly, we can still kill animals by using traps. If dragons were living, breathing animals (as in, no supernatural elements or magic involved), what kind of reason could force the usage of melee weapon against them? [Answer] Bows are not as useful against dragons. The dragon’s fire breath gives it a superior ranged attack as well. A one-on-one ranged duel with dragon usually ends in the dragon's favor, save in the case of the most skilled bow man. Even massing a large body of archers is not the best. The dragon will either close the gap and enter melee combat with the poorly equipped archers, or simply fly away. In addition, many of the arrows are turned harmlessly away by the thick hide. Pikes and spears also fare poorly. Again the dragon’s breath attack is perfectly suited for this. In addition its tail (and many of its limbs) give it a reach superior to these melee weapons. The best bet is for one or two skilled fighters to step within the reach of the dragon. A breath attack at this range may also harm the dragon. The tail becomes useless. You only have to worry about the limbs and the body itself. If the dragon tries to crush you with thier body, simply pull a Samwise/Shelob and let the dragon's own weight impale itself on your sword. At this range the softest points of the dragons hide become exposed, and you get close enough to target major arteries to the limbs. Most dragon casualties come from loss of blood after the battle itself. The close range also allows for greater precision, for sometimes the hide is still thick enough to blunt a blade's strike. If the warrior can strike the same spot several times they may finally strike deep enough to cut that artery. If you can get to this range, a bold but unskilled warrior might even be able to slice the aforementioned artery. Perhaps performing a suicide attack, letting the dragon grasp his body with a deadly claw, just to be let within range to swing an axe/pick or other blade in such a way that will lead to the dragon bleeding out. [Answer] 1. **Small dragons?** You did not specify how big the dragons are. If they are small and move fast they would be hard to hit with a spear or arrow. A sword would be ok, or a big stick, or a tennis racquet. 2. **Forceful blows.** It is possible to apply more force if you put your body weight behind a blow. You have all of your own mass as well as that of the weapon and the force you generate. With a projectile you have only the mass of the projectile. The other thing is that if you are holding the tool you can bear down and exert continuing force; the projectile expends its force and bounces off. You could hold a spear or sword and drive it in. Likewise a heavy axe exerts more force per hit and you can deliver multiple hits once you are close. If you have something with impenetrable armor then the large mass weapon is the option: an axe or mace. Plate armor is great against edges but if you hit a guy in the helmet with a 8 pound maul that energy is going somewhere. Likewise the dragon: crushing blows will hurt even through armor. The extreme case: Hercules could not hurt the Nemean Lion with any weapon and had to strangle it to death with his arm. 3. **Sawing action.** If something is extremely tough, to cut it you might want to lean into it and saw at it. There is no way to do that with a projectile. Consider why saws are used to cut trees instead of flat sharp blades, or why steak knives are serrated. I am not sure a saw is considered a melee weapon but you could definitely have a serrated dragon sword, which would be fairly badass as well. The serrated sword would be a slashing weapon. 4. **Poison delivery**. Poison arrows and spears are great, but if you have a very limited amount of the poison available you might not want to risk the arrow bouncing off and failing to deliver. If you have a weapon like a thrusting spear you can be more sure of getting the poison where it is supposed to be. 5. **Fearless.** You are not afraid to close in. As usual @AlexP puts good stuff in the comments; stupidness or cluelessness are excellent reasons you are not afraid to close with the dragon. But maybe you are very quick and very cocky and you think you can move quick enough to not get hit. [Answer] Three options, perhaps one of them helps: * Dragon hunters live longer if they wear full knightly armor. Knights are trained to use the lance and either a sword or a warhammer or mace. Horses are easily spooked by dragons, so the lance is out. That leaves the sword. * Dragons are smart and agile for an animal. Hunting them involves a trek through the wilderness where they make their lairs. That can be difficult with a long spear, or a heavy matchlock arquebus. * Bagging a dragon is reserved for high-status individuals, not masses of common soldiers. It wouldn't do to have a random ruffian save the kingdom and marry the princess. And high-status dragon hunters carry a sword. No artist would ever depict a commoner killing a dragon, if that were to happen. [Answer] Historically speaking melee weapons were used by rich and wealthy people, while ranged weapons were reserved for lower classes. Since one wants to praise the nobility and courage of the high classes (paying for having the story written or chanted) it makes perfectly sense that the valiant chevalier slaying the dragon uses an expensive sword for rich people and not a slingshot which could be afforded by even poor farmer. [Answer] **Dragons are proud** If you try to kill it with a bow or a trap you had best finish it off before it knows you are there or it will come for you and your people using all its formidable weapons, and since they are fast, clever and tough you aren't very likely to succeed. But if you challenge it to a limited fight you may have some chance, and it won't take it's wrath any farther than yourself. \*This pretty much requires dragons to be sentient which contradicts the 'animal' in the question. **Dragons fly** A hurt dragon is willing to flee and there is little chance a human can stop it. The only option is to get close and hold on. This means you need weapons usable in one hand like a sword or axe. **Dragons have armor** The weak spots are not exposed except from close range and even then only when it moves in a certain way. This requires active melee fighting to attempt, and the speed and precision of a sword to succeed. [Answer] Dragons, in addition to being extremely dangerous, are usually described as having some sort of natural armour, with the exception of the wings. As with late medieval armour only extremely powerful ranged weapons will have any hope of penetrating and given the extra mass of the dragon these weapons are less likely to to do it harm. With that in mind a dragon hunt would likely involve a large party and have stages. All this is assuming pre-gunpowder, as once you things like reliable, powerful, elephant guns the situation shifts to "just bring a gun". The first stage is to grounding the dragon. Ideally you want to sneak up on it while it's on the ground, if it is you can skip straight to the next stage. But if it's flying you'll need to bring it down. At this stage you're using bows, slings, scorpions and similar ranged weapons to punch holes in the wings and bring it down. There's always a chance that a lucky shot or the impact of (likely controlled) crash will kill it but that's not something you should count on. Stage two is where the melee weapons come in. You'll be throwing nets, ropes, and the like to foul the movement of its limbs and tail. At the same time you'll be on the side shoving spears in its face so it has to point its head away from you or lose an eye. You'll also be using long spears with an armour piercing spikes to hit it in the flanks and bleed it. Stage three begins after the dragon has been bled and exhausted. Now that the dragon is weaker and less dangerous. At this point the bravest among you will move in with warhammers, maces, and maybe axes. The objective will be to break limbs and take them out of the fight. Finally you'll go after the neck, and for the kill. Essentially if the dragon follows the usual pattern of having armoured scales except on the wings only a lucky shot with a pre-gunpowder ranged weapon will do significant damage. Armour piercing melee weapons would be the order of the day. [Answer] The classic way to kill a dragon was the way that Beowulf and Sigurd (Fafnirsbane) Sigmundson used. First, dig a pit in the dragon's usual tracks and hide therein. Wait for the dragon to come by, walking or slithering over your pit. Stab upwards, ideally killing the unsuspecting dragon. This stab may be done with a short spear, but oddly a good sword is probably better, as it will not break as easily and can be found short enough for a shallow hole. A lindon shield supposedly helps against dragon fire. Wood is a good insulator, and doesn't burn fast enough that you cannot get it off before you are burned, especially if the shield is particularly thick. May The Allfather Be With You. [Answer] **Status-seeking** Killing dragons isn't (mostly) about getting rid of them. It's about risking your life doing impressive things for social status. The dragon hunt, then, goes something like a bull-fight. The dragon is drawn into prepared ground, harassed and weakened by archers, traps, and nets, and then well-armored warriors with melee weapons head in to finish off the beast in an appropriately glorious fashion, while admiring crowds look on and artists prepare to immortalize the moment. Particularly brave knights might even face off against the smaller sorts of dragons without all the prep work (solo or in small groups). Of course, you could use different weapons, but then they wouldn't be proper *knightly* weapons, and if you don't think that matters, then you're missing the point entirely. [Answer] If we focus more on the firearms aspect of the question, one area in which there is a large disparity between the effectiveness of firearms and melee weapons is with 'bulletproof vests' vs 'stab resistant armor. The two behave [quite differently](https://crimefictionbook.com/2015/06/17/can-a-bulletproof-vest-also-stop-a-knife/), as bulletproof vests are designed to disperse the (relatively small amount of) kinetic energy present in a bullet, whereas stab resistant vests are designed to catch the weapon and snag it so it can't penetrate much deeper (Article linked goes into much more depth). Knifes, swords, and clubs all have substantially higher kinetic energy than a bullet. It's possible that the scales of the dragon could have an structure similar to that of a bulletproof vest - meaning that the most effective way to kill it would be either stabbing or blunt force attacks. However, depending on the technology level of the dragon-slayers, explosives and mounted machine guns may make this a moot point. [Answer] **Not hunting, but killing with melee weapons.** The answer is to tire the dragon out. While my mind is a bit hazy on the details, let's start with that this ain't a sprint, but it's a [marathon](https://en.wikipedia.org/wiki/Persistence_hunting). And we are going to need lots of manpower for this. All creatures need to rest, and as a dragon is probably an ambush predator, it will not that unlimited endurance. --- **Stage One: Grounding**, use every ranged weapon you have to make it stop flying. Aim for the wings. Big bolts, small rocks, don't matter, bring it. Unleash it. Don't get killed. **Stage Two: No Sleep, No Rest** (For the wicked) Now use horsemen with ranged weapons, bows will work, but slings will do, to keep the dragon awake. And if can, moving around. Keep this up for several days. Yes, days. Maybe a week or more. I don't know, just keep it up. Do this till it can't move anymore due to fatigue. **Stage Three: Hold in place** with wires, nets, anything to stop it moving. You want to control the beast. **Stage Four: Aim carefully** Depending on your outlook of live and willingness to look awesome, you can kill the very tired dragon. *Ranged*: Use a large bolt thrower. Aim carefully, shoot to kill. More is better. *Close Up:* Bring your sword if you must. This here creature has lost the will, or the energy, to fight. I'll bring my axe if you don't mind, better for chopping necks. **Stage Five: Mount** the skeleton some where you can boast about it. And make a nice painting of you slaying the dragon. Don't mention the details of just tiring out the dragon. Or the use of nets and ropes. *No, in the end it was just you against a mighty dragon.* [Answer] The **lack of anything better to use**, assuming it isn't because of cultural stupidity. Any other reason would be a handwave grasping at straws. Every depiction of a dragon I've ever seen **breaks the square cube law**, so having scales that a [ballista](https://en.wikipedia.org/wiki/Ballista) can't penetrate would break it even more. Your universe is going to **need to have *not* invented *so* many things** (for there to ever be a situation where you have an understanding of metallurgy, but absolutely no projectile weapons of any sort - because if you have any, we'll adapt them to make it work), it's not even funny. [Answer] Nobody hunts large animals with bows and arrows. All that would do is annoy them. Same with javelins. They simply don't have enough force behind them. You'd need hunting spears at the very least to do enough damage. Arrows and javelins are used, but only to drive the animal, either into a trap or more often to wear it down so that the [coup de grâce](https://en.wikipedia.org/wiki/Coup_de_gr%C3%A2ce) can be delivered safely. With a giant, flying, fire-breathing reptile, that isn't going to work. It can fly out of any trap you set and can simply fly away if you try driving it, assuming, of course, it doesn't simply turn around and roast you. The dragon's ranged weapon beats your ranged weapon, and it can move faster. Unless it's attacking a fortified town with wall mounted ballistae, ranged weapons literally won't cut it. Your only option is to get in close enough to stop it flying away, regardless of how many men you lose in the attempt. Preferably in a cave or some other constricted terrain, so it can't simply leap over their heads and take flight. And of course, you want to maximise damage per blow, since the longer the fight drags on, the more of your people will die. Hence, axes and swords--even if they can't kill it, they can at least cripple it, so that the next lot can finish the job. [Answer] ## Location, location, location There are two primary locations one might be fighting a dragon: 1. **In the open** Here the dragon has all the advantages: its strong hide protects it from arrows, it's tail can swipe any spearmen out of range, if hoarded on all sides it can set the entire area around it on fire, if wounded by a weapon like a ballista it can fly away and recoup. Even any attempts to trap it with nets or pits will fail due to the dragons strength and cunning. The vast and insurmountable advantages of a large dragon against all conventional weaponry in the open field are the reason attacking it cannot be compared to hunting large animals and will always be able to avoid close encounters by attackers with melee weapons. 2. **In the dragon's lair** For this reason a much better strategy is attacking the dragon at it's weakest: when asleep or resting in its lair, after it has burnt and ravaged the surrounding countryside and is no longer met with open resistance. Sending a group of assassins to kill a gorged, sleeping dragon in the enclosed space of its lair with melee weapons gives several advantages: * *Other weaponry unweildy:* In the close quarters and stealthy approach to a dragon's lair, teams of soldiers carrying heavy nets, chains or rolling up a ballista would alert the dragon before our approach. Similarly with firing weapons we might be able to fire a single shot, but will have to rely on melee weapons to finish the job off. And the more the assailants carry, the less likely they are to complete a silent approach. * *Night time approach:* assuming the dragon has to sleep, and flying at nighttime can be dangerous, humans will have the advantage of being able to approach its lair under cover of darkness. This allows them to get much closer than when it is rampaging in the open and allows for the use of melee weapons in a close encounter. * *Information:* a close inspection of a sleeping dragon may allow us to discover any potential weak spots. Even if the attack fails this information may help in future attacks and a precise hit with a close-range weapon is most likely to exploit such weaknesses. * *First strike:* if the dragon does not wake, we are able to attempt a single possibly fatal or at least crippling attack with a strong melee weapon. * *Reduced space:* when surprised inside its lair a dragon lashing out may become disoriented: any fire it starts will fill the air with smoke, whipping its tail about will raise dust. As it focuses on a primary attacker, the dragon may not notice others hiding behind pillars or waiting underneath/behind the dragon. In the confusion there may be many opportunities for a direct attack with a melee weapon. * *Lair destruction:* If a dragon is repeatedly attacked in its lair at close quarters and forced to fly away and sleep elsewhere, the dragon could be convinced to leave the region entirely. Even if not killed, repeatedly attacking and wounding a dragon in its lair may convince it to fly over the closest mountain range and continue its rampage elsewhere. [Answer] Might not be historically accurate, but in The Once and Future King they hunt a boar by surrounding it with men armed with (non-throwing) spears, ready for it to charge. If they certainly need to get this dragon without it running and have enough men, they could adopt a similar strategy [Answer] While one of the most highly upvoted comments states that swords aren't used for hunting, they are incorrect. Swords & knives are used for killing prey that has been trapped and is either so badly wounded / poisioned it is unable to fight back, or constrained to the degree that it is unable to fight back. Thus a good reason to attack a dragon with a sword or other melee weapon is that it is now safe to get that close; and one does not have a ranged weapon on you, or have the requirement to preserve ammunition. One might ask how the trap might be prepared to capture or poision the dragon, but this is somewhat out of scope of the question since one could use mechanical traps (eg nets / falling objects etc), poision darts or any other means; and the question isn't how to trap, but why would one be forced to use melee. ]

[Question] [ Images like [this](http://eleven-thirtyeight.com/wp-content/uploads/2016/02/concorddawn.jpeg) [](https://i.stack.imgur.com/2hb4D.jpg) and [this](https://c4.wallpaperflare.com/wallpaper/677/315/754/3d-space-wallpaper-preview.jpg) [](https://c4.wallpaperflare.com/wallpaper/677/315/754/3d-space-wallpaper-preview.jpg) are common in sci-fi/fantasy settings, for the obvious "rule-of-cool" reasons. And while the 'rule-of-cool' is certainly worth using (in moderation) when appropriate, I can't help but wonder just how realistic are giant cracks in rocky planets? Since that question, alone, is quite broad, here are some parameters to narrow it down: 1. We'll assume a geologically dead ([relatively] cool, [mostly] solid core) planet, to avoid having all that liquid hot magma immediately flowing in to the crack and filling it in. 2. Since "planet" generally indicates that it's big enough for its own gravity to make it (roughly) spherical over time, but also considering that this tendency will also work to close the crack, we'll go for a small-ish planet, let's say about 3400km radius (about the size of Mars) 3. And to give ourselves the best chance for some semblance of realism, we'll keep the crack much smaller than those images. Let's say 7000km long (roughly a third of the circumference of the planet), and 1000km wide at its widest, and 1500km deep at its deepest. 4. As for what the planet is made of, let's stick with the same elements in the same proportions as Earth. 5. To make it a place where a story can take place, let's also give it an atmosphere and climate zones that can support human life. 6. The atmosphere, together with earthlike composition, should also mean earthlike erosion takes place (though not necessarily at the same rates, due to the reduced gravity) 7. To avoid too many erosion complications, lets also say that even though the planet would likely have massive bodies of water in order to have a similar atmosphere to Earth, let's assume the crack is entirely continental, does not intersect any oceans or seas, or any other significant bodies of water. **Is this crack a stable**( >10,000 years ) **geological formation? Or does gravity and erosion significantly**(an order of magnitude) **change its dimensions in a short**( <10,000 years ) **time?** [Answer] There is a crack in Mars called Valles Marineris. It is about as long as the contiguous USA. [](https://i.stack.imgur.com/LzHIx.jpg) And here is a 3D rendering of it: [](https://i.stack.imgur.com/fasVr.jpg) This rift is comparable to your specs in length and width, but not depth (only 7 km). 1500 km is a quarter of the way through Earth's surface to it's inner core. That would never be stable. So I think something like the Valles is the best you can do for a proper crack. Larger than this... maybe if you dried Earth's oceans and called the seafloor a crack. Would be mostly shallower than Valles Marinwris though. [Last time the Earth did get a crack the size you ask for was when it impacted against a Mars-sized planet a few billion years ago.](https://en.wikipedia.org/wiki/Giant-impact_hypothesis) Earth quickly (in geological terms) reformed itself into a mostly smooth shape. [Answer] No, it couldn't be remotely stable, and erosion is not going to matter. Even assuming the crack got formed by some very 'gentle' process that didn't destroy the planet outright, you’ve got to consider the scale of the pressures involved in a crack like that. The material making up the side of the crack has to support the weight of all the material above it. A quick google gives the breakdown pressure of stone at anywhere from tens to a couple hundred megapascals for the strongest types. On Earth, you exceed those pressures between 1 and 10km deep. That’s probably why we don’t have canyons deeper than that. Your crack is vastly deeper, so the walls of the crack have no chance of holding up. How would that play out? Your planet is a bit smaller than Earth but the same composition, so your surface gravity will be about half of Earth's. The gravity at the bottom of the crack will be a bit less than a third of a G. I'm too lazy to do the integration, so let's use a constant 0.4 G's for gravity in the crack. Using that, the pressure forcing the walls together at any given point is just the weight of the stone above. Assuming a cubic meter of crack wall masses between 3000kg and 5500kg, then half-way down the crack the pressure will be between 9 billion and 16 billion pascals. At those pressures, the strength or stiffness of the walls themselves is a rounding error. The walls will flow under the stress, become molten due to frictional heating, and be forced together by the pressure as fast as they can move. The pressure is enough to accelerate the walls at 300,000 G's. I'm unsure if the speed of the walls is limited like Seismic P-waves or whether you can just apply Newton's laws, but the walls will cross that 500km gap in a fraction of a second either way. It will happen sooner deeper down where the pressure is greater and the separation smaller, so the crack will seal itself up like a zipper from bottom to top. The violence of the impact as the walls snap together will be profound. The force will send a blast wave up towards the surface, ejecting a mass of molten rock out into space. The volume of your crack is something like 1% of the volume of your planet if I’m picturing it correctly. That means that when it snaps closed, the radius of your planet has to shrink by 0.33%. That doesn't sound like much, but it comes to an 11km drop for the entire surface of the planet. *Lots* of kinetic energy released. So picture a wave several km high circling the planet at several km/s until all that energy gets converted to heat.. Needless to say, this is *far* worse than the meteor that killed the dinosaurs. Even if conditions were earthlike before the crack closed, they won't be afterwards. [Answer] The volume of the hole is about 10,500,000,000 cubic kilometers. The density of Earth [is about](https://hextobinary.com/unit/density/from/earthdensity/to/tnmetricpkm3) 5,518,000,000 tonnes per cubic kilometer. The mass of the hole was about 6$\cdot$1022 kg. As such, the surface gravity of each side of the hole from similar chunks of planet over the long edge [is about](https://www.wolframalpha.com/input?i=surface+gravity+calculator&assumption=%7B%22F%22%2C+%22GravitationalAcceleration%22%2C+%22r%22%7D+-%3E%227000.009+km%22&assumption=%7B%22FS%22%7D+-%3E+%7B%7B%22GravitationalAcceleration%22%2C+%22g%22%7D%7D&assumption=%7B%22F%22%2C+%22GravitationalAcceleration%22%2C+%22M%22%7D+-%3E%220.6%C3%9710%5E23+kg%22&assumption=%22FSelect%22+-%3E+%7B%7B%22GravitationalAcceleration%22%7D%7D) 0.8 cm/s2. Over a thousand years around ten billion seconds pass. That's around 600,000 kilometers of acceleration. It's probably stable over ten years. Over a hundred years a lot has probably collapsed in there. By a thousand years, the planet has probably smoothed over a lot. That's a lot of acceleration for the rocks to undergo. [Answer] # Hot Mess: This is a tricky question to answer. The first big question is, "What caused the crack?" The likely sources of the damage will seriously affect how the crack looks and how it fills in. I'm assuming with a geologically stable planet that it's not plate tectonics. So the likely culprits are massive impacts (which would create deep craters, not rifts) or some kind of gravitational effect like a black hole making a close fly-by at great speed and creating a short differential gravity effect. Most of the events that would cause such a rift will be BIG events. The effect is likely that the rock in the surrounding area will get very hot and liquefy from friction. Volcanoes are already created from the friction of continental plates rubbing against each other, and the Marianas trench, the effect of a subduction zone generating such volcanoes, only gets to a mere 11 km. So it's likely the disaster itself will largely fill itself in, or at least significantly affect it's shape. Most of the disasters that would create such a hole would wipe out most life on the planet. While it's a little hard to deconstruct the Chicxulub event, the impact crater was something like 20 km deep, and that resulted in a mass-extinction event completely altering life and climate for the planet. That's just a TINY fraction of the 1500 km hole you're talking about. The atmosphere and oceans of the planet would likely be blown off by something able to do this kind of damage. If the oceans didn't simply evaporate into space, they would likely start filling in the rift as they rained back to the surface. Side fissures of this hole would likely break into an ocean SOMEWHERE. This might actually be a good thing for your rift's survival, as the mass of the water will partly compensate for the shift in the mass of all that rock that's now missing. The water will apply pressure on the rock adjacent to it, help cool things, but also seep into the adjacent magma generated from the heat and create very volatile gassy eruptions. For your 10,000 years AT LEAST, the area will be a volcano-strewn wasteland. The shape of your planet will possibly be warped by the causative event. While the appearance of the rift might seem to match your depths, the actuality might be that the surface has buckled sideways and the rift is really two huge, sinking mountain ranges with a deep fissure between them. Again, all this deformation is likely to generate a ton of heat and melt rock all over the place. So in my opinion, you'll be able to spot the effects of this rift for millions of years, but the rift will most likely fill in with molten rock and water within a few decades as the bending and flexing of the planet destroys all life. [Answer] Short answer: I suggest you use a small, artifically shaped and terraformed mostly iron nickel world to have a crack which is very large absolutely and also relative to the size of the world. Long Answer: Part One of Three: The Difficulty of Using a Natural Planet. according to the question: > > We'll assume a geologically dead ([relatively] cool, [mostly] solid core) planet, to avoid having all that liquid hot magma immediately flowing in to the crack and filling it in. > > > and: > > Since "planet" generally indicates that it's big enough for its own gravity to make it (roughly) spherical over time, but also considering that this tendency will also work to close the crack, we'll go for a small-ish planet, let's say about 3400km radius (about the size of Mars) > > > And: > > As for what the planet is made of, let's stick with the same elements in the same proportions as Earth. > > > And: > > To make it a place where a story can take place, let's also give it an atmosphere and climate zones that can support human life. > > > And: > > The atmosphere, together with earthlike composition, should also mean earthlike erosion takes place (though not necessarily at the same rates, due to the reduced gravity) > > > Are all those factors consistent with scientific possibilities? Are all those factors consistent with each other? Take the breathable atmosphere. On Earth photosynthetic lifeforms gradually evolved and began to produce an oxygen rich atmosphere. On Earth in took about four billion (4,000,000,000) years for an oxygen rich atmosphere breathable for humans to be formed. If the planet is going to lose all its atmosphere in three billion years, or three million years, or 518,283,492 years, or 105 years, or any other length of time shorter than the billions of years it will take to produce a breathable atmosphere, the planet will never produce a breathable atmosphere and will never be habitable for humans or for other lifeforms that need oxygen. A number of factors influence what type of atmosphere a planet has, including what type of atmosphere it oriignally forms. For example, having a strong magnetic field to deflect charged particles in the stellar wind from the planet will protect its atmosphere from being gradually lost as the stellar wind knocks them away. But the most important factor in how long a planet retains its atmosphere is its escape velocity. The escape velocity of a planet and its surface gravity change with the mass, volume, and density of a planet. As the surface gravity increases, the escape velocity also increases, though not at the same rate. There are different formulas for calculating a world's surface gravity and its escape velocity. According to *Habitable Planets for Man*, Stephen H. Dole, 1964, <https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf> on pages 34 to 35, a rough formula to calculate the time it takes for a planetary atmosphere to be reduced to 1/e, or 1/2.718, or 0.368, of its original amount, shows that it depends strongly on the ratio between the sescape velocity of the planet divided by the root-mean-square velocity of the molecules in centimeters per second. The higher the temperatures of the molecules, the higher their root-mean-square velocity, and the faster they escape. Table 5 on page 35 show that where the ratio is one or two, the molecules will escape so fast that the planetary atmosphere will be reduced to 0.368 of its orginal amount in zero seconds. If the ratio is three, it will take a few weeks. If the ratio is four, it will take several thousand years. If the ratio is five, it will take about a hundred million years, and if the ratio is six, it will take infinite time. On page 36 Dole mentions that gases escape from the Earth high in the atmosphere, in the exosphere, and the temperature there is much higher than the surface temperature on Earth, about 1000 to 2000 degrees K. On page 54 Dole says: > > However, if we take as a rough approximation that maximum exosphere temperatures as low as 1000 K are not incompatable with the required surface conditions of a habitable planet, then the escape velocity of the smallest planet capable of retaining atomic oxygen may be as low as 6.25 kilometes per second (5 x 1.25). Going back to figure 9, this may be seen to correspond with a planet having a mass of 0.195 Earth mass, aradis of 0.63 earth radius, and a surface gavity of 0.49 *g*. > > > Such a planet would lose more than half of its atmosphere every hundred million years, and would have to replace atmosphere fby various processes to retain it for billions of years to produce an oxygen rich atmosphere. And of course if it turns out to be necessary for the maximum exopshere temperatures to be closer to 2000 K for the surface temperature to be high enough, the planet would lose atmosphere even faster. A radius of 0.63 that of Earth's radius of about 6,371 kilometers would be a radius of about 4,013.73 kilometers, which is about 1.18 times the radius, and thus would have about 1.643 times the volume of, your specified planet with a radius of about 3,400 kilometers. I note that Dole believed that a planet with 0.195 Earth's mass and a radius of 0.63 Earth's radius would be capable of retaining an oxygen rich atmosphere, but doubted that such a small planet could produce an oxygen rich atmosphere. Dole made two separate calculations of the minimum mass necessary for a planet to produce an oxygen rich atmosphere. One calculation indicated a minimum mass of 0.25 Earth, another a minimum mass of 0.57 Earth mass. Dole rather arbitarily selected 0.4 Earth mass as the minimum mass of a planet capable of producing an oxygen rich atmosphere. Such a planet would have 0.78 the radius of Eerth (4,969.38 kilometers) and a surface gravity of *g*. It would exceed your 3,400 kilometer planet by 1.461 times, and its volume by 3.118 times. Part two: Designing a Terraformed World With a Huge Crack. But the situation is not that bleak for your 3.400 kilometer radius planet having a breathable oxygen atosphere. Posssibly an advanced civilization terraformed the planet to have an artificial oxygen rich atmosphere. A planet with 0.195 times the mass of Earth could retain 0.368 of the atmosphere it was given for about 100 million years if the exopshere temperature was only 1000 k, which might be long enough to seem worth while to the advanced civilization. Dole says on page 36 the main source heating the exosphere gases of Earth is far ultraviolet radiation from the Sun. If the star is a cooler star than the Sun, it might prodcue much less far ultraviolet radiaiton and the exosphere temperature could be 1000 K or less while the planet's surface was heated up to be warm enough by the star. Or maybe the advanced civilization would build fusion generators to heat up the surface of the planet while the exosphere was heated up only by radiation from the star. Of course your planet would be a lot smaller than Dole's 0.195 Earth mass planet. A planet with a radius of about 3,400 kilometers would have about 0.5337 the radius of Earth, 0.2848 the surface area, and about 0.1520167 the volume. Thus if it had The same overall density as Earth it owuld have 0.1520167 the mass of Earth. According to this online calculator <https://philip-p-ide.uk/doku.php/blog/articles/software/surface_gravity_calc> your planet would have 0.53 *g* surface gravity. According to this escape velocity calculator <https://www.calctool.org/CALC/phys/astronomy/escape_velocity> It would have an escape velocity of 5.97092 kilometers per second. Giving your planet 0.17 the mass of Earth, it would have an escape velocity of 6.31423 kilometers per second, a little more than the 6.25 which Dole considered to be the minimum for retaining an atmosphere. It would have an overall density about 1.0156 that of Earth. And it would have a surface gravity of 0.6 *g*. So basically a planet capable of having an oxygen rich atmosphere, even one produced artificially, would have a surface gravity at least about 0.5 times that of Earth. The lesser surface gravity would help a bit in retaining the crack for long periods, but would not be a very big help. Suppose that the hypothetical advanced civilization that terraforms the planet doesn't count on the escape velocity of the planet to retain the artifical atmosphere, but builds a roof (possibly suported by air pressure) around the entire planet to retain the atmosphere. Presumably there would be giant airlocks in the roof to let spaceships land and take off. > > A shellworld[1](https://philip-p-ide.uk/doku.php/blog/articles/software/surface_gravity_calc)[3](https://www.calctool.org/CALC/phys/astronomy/escape_velocity) is any of several types of hypothetical megastructures: > > > One of which is: > > An inflated canopy holding high pressure air around an otherwise airless world to create a breathable atmosphere.[4](https://en.wikipedia.org/wiki/Shellworld) The pressure of the contained air supports the weight of the shell. > > > <https://en.wikipedia.org/wiki/Shellworld> Asteroid 16 Psyche is about 278 by 272 by 164 kilometers, so its largest dimenision is 1.69 times its smallest dimension, and its "highest" surface point is about 57 kilometers above its "lowest" surface point as measured from the center of mass. > > Several possible origins have been proposed for Psyche. The earliest of these was that Psyche is an exposed metallic core resulting from a collision that stripped away the crust and mantle of an originally larger differentiated parent body some 500 kilometers in diameter.[11] Other versions of this include the idea that it was not the result of a single large collision but multiple (more than three) relatively slow sideswipe collisions with bodies of comparable or larger size.[34] However, this idea has fallen out of recent favor as mass and density estimates are inconsistent with a remnant core.[8] > > > <https://en.wikipedia.org/wiki/16_Psyche#Origin> But even if Psyche is not the remnant nickel iron core of a dwarf planet shattered by collisions it is theoretically possible for such remnant iron nickel cores to remain after collisons shatter their larger parent bodies. Such metallic asteroids could get many times much larger than 16 Psyche before their gravity became strong enough to force them into spherical shapes, sepecially since an iron nickel core would be much stronger than stone. So I can easily believe that an iron nickel alloy object could get large enough to have a radius of 100 kilometers or larger before it was pulled into a spheroid by its gravity and reached what is called hydrostatic equilibrium. > > Solar System objects more massive than 1021 kilograms (one yottagram [Yg]) are known or expected to be approximately spherical. Astronomical bodies relax into rounded shapes (spheroids), achieving hydrostatic equilibrium, when their own gravity is sufficient to overcome the structural strength of their material. It was believed that the cutoff for round objects is somewhere between 100 km and 200 km in radius if they have a large amount of ice in their makeup;[1](https://www.rand.org/content/dam/rand/pubs/commercial_books/2007/RAND_CB179-1.pdf) however, later studies revealed that icy satellites as large as Iapetus (1,470 kilometers in diameter) are not in hydrostatic equilibrium at this time,[2](https://philip-p-ide.uk/doku.php/blog/articles/software/surface_gravity_calc) and a 2019 assessment suggests that many TNOs in the size range of 400–1000 kilometers may not even be fully solid bodies, much less gravitationally rounded.[3](https://www.calctool.org/CALC/phys/astronomy/escape_velocity) Objects that are ellipsoids due to their own gravity are here generally referred to as being "round", whether or not they are actually in equilibrium today, while objects that are clearly not ellipsoidal are referred to as being "irregular". > > > <https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size> So I will rather arbitarily assume that an iron nickel alloy asteroid, made of stronger material than ices or stones, could be between 100 kilometers and 2,000 kilometers in radius before its gravity pulled it into a spheroidal shape. So possibly the hypothetical super advanced society in the story finds a large irregular iron nickel asteroid and sculpts it into an almost spheriodal shape, except for a large crack in it, selling the excess metals, puts a transparent shell around it, gives it atmosphere, dirt, water, plant and animal life, and creats a tiny habitable world that has a giant crack or scar, like a really really grand canyon, as a tourist attraction. The crack may be large enough to be very impressive when seen from ships in outer space and should be very impressive as seen from the ground. An spherical iron nickel body in that size range (after being sculpted into shape) would have from 0.0156951 to 0.3139224 the radius of Earth, and thus would have from 0.0002463 to 0.0985472 times the surface area, and from 0.0000038 to 0.0309361 the volume of Earth. If it was made of material with the same overall density as the Earth, it would have 0.0000038 to 0.0309361 the mass of Earth. But the overall density of Earth is 5.514 grams per cubic centimeter, while pure iron nickel meteorites similar in composition to this hypothetical world have densities of 7.9 grams per cubic centimeter, 1.4327167 times as great. A 2,000 kilometer radius iron nickel world would have about 0.3139224 the radius of Earth and about 0.0443226 Earth's mass. It would have a surface gravity of 0.45 *g* and an escape velocity of 4.20371 kilometers per second. A 100 kilometer radius iron nickel world would have about 0.0156951 the radius of Earth and about 0.0000054 Earth's mass. It would have a surface gravity of 0.02 *g* and an escape velocity of 0.207507 kilometers per second. The 2,000 kilometer radius iron nickel world would have almost sufficient escape velocity to retain an atmosphere naturally, but its surface gravity would not low emough to help a lot in making the crack last long. The 100 kilometer radius world would have a surface gravity low enough to make the iron nickel walls of the great crack last for a long time. And the smaller size of the world would mean that a equally sized crack would appear much larger relative to the radius of the world. So my recomendation for a world with a really spectacular and relatively permanent crack would be an iron nickel asteroid sculpted into the shape of a spheriod with a very large crack, and terraformed with an artifical atmosphere held in by a transparent air supported roof over the entire little planet. People who can do materials strength calculations may be able to calculate the maximum height and angle of incline of the scar for a world with a specific surface gravity. Part Three: Other Problems With a Natural Planet There are other problems with your requested natural planet with a crack. Your request for simular materials to Earth is inconsistent with the iron nickel world which would be best for artificially sculpting into a spheroid with a giant crack. An advanced society could sculpt an irregular stony little world into a spheroid with a giant crack. but the weaker strength of stone would result in a smaller and less spectacular crack for a world with the same surface gravity. In recent decades scientists have done a lot of speculating and calculating about the conditions necessary for life on other worlds. Note that unlike Dole, most scientists consider the general case of habitability for liquid water using lifeforms in general, instead of humans and other lifeforms with the same requirments as humans in particular. Many worlds which they consider habitable for some hypothetical lifeforms would be deadly to humans. Once such paper is "Exomoon habitability constrained by illumination and tidal heating", by Rene Heller and Roy Barnes, 2013. They dscuss the mass ranges of potentially habitable worlds on pages 3 & 4: > > A minimum mass of an exomoon is required to drive a magnetic shield on a billion-year timescale (Ms ≳ 0.1M!, > Tachinami et al. 2011); to sustain a substantial, long-lived atmosphere (Ms ≳ 0.12M!, Williams et al. 1997; Kaltenegger > 2000); and to drive tectonic activity (Ms ≳ 0.23M!, Williams et al. 1997), which is necessary to maintain plate tectonics and > to support the carbon-silicate cycle. Weak internal dynamos have been detected in Mercury and Ganymede (Kivelson et al. > 1996; Gurnett et al. 1996), suggesting that satellite masses > 0.25M! will be adequate for considerations of exomoon > habitability. This lower limit, however, is not a fixed number. Further sources of energy – such as radiogenic and tidal heating, and the effect of a moon’s composition and structure – can alter our limit in either direction. An upper mass limit is > given by the fact that increasing mass leads to high pressures in the moon’s interior, which will increase the mantle viscosity > and depress heat transfer throughout the mantle as well as in the core. Above a critical mass, the dynamo is strongly > suppressed and becomes too weak to generate a magnetic field or sustain plate tectonics. This maximum mass can be placed > around 2M! (Gaidos et al. 2010; Noack & Breuer 2011; Stamenkovi% et al. 2011). Summing up these conditions, we expect > approximately Earth-mass moons to be habitable, and these objects could be detectable with the newly started Hunt for > Exomoons with Kepler (HEK) project (Kipping et al. 2012). > > > <https://arxiv.org/vc/arxiv/papers/1209/1209.5323v2.pdf> Note that an internal dynamo is considered necessary for a magnetic field to help protect the atmosphere and for plate tectonics. Your desire for a geologically dead planet with little liquid magma, to maintain the crack, would probably result in a planet without a magnetic field or plate tectonics, and so it would not remain naturally habitable for a very long period geologically. Of course, if such a geologically dead planet was terraformed by an advanced society, as I suggested, they could keep it habitable for thousands or maybe millions of years, which might be long enough for their needs and for the events in a story. Conclusion: For the reasons given above, I suggest that the most spectacular possible crack in a habitable world would not be in a naturally habitable world but in a rather small iron nickel world artifically sculpted into a spheriodal shape with abig crack, and with an artificial atmosphere kept in by a roof over the whole world. [Answer] No, by definition. People still debate if Pluto deserves to be called a planet or not. The [current definition](https://en.wikipedia.org/wiki/IAU_definition_of_planet) has three elements: * In orbit around the sun. * Large/massive enough to reach a [hydrostatic equilibrium](https://en.wikipedia.org/wiki/Hydrostatic_equilibrium#Planetary_geology), a roundish shape. * Has cleared the orbit of other objects (the Pluto sticking point). So if it is able to retain a serious crack, and not just a few wrinkles on the surface like [Mars](https://en.wikipedia.org/wiki/Valles_Marineris), it is too small to be called a planet or even a [dwarf planet](https://en.wikipedia.org/wiki/Dwarf_planet). It would be a lesser object. [Answer] No, it is not stable. It's hard to account for everything that would effect such a scenario, but just to name a few things that would happen, first, all of the liquid water on the planet would try to fill the gap. Oceans would drain into the chasm even as magma tried to drain out of it. This would only add to what I think would be the real undoing of an event like this - the imbalance. Think about the momentum of the planet, the speed of its spin. A cut into the planet like this would change the distribution of weight across the planet drastically enough to change the rotation, the eccentricity, and probably lots of other stuff. The atmosphere would go haywire. Of course, this period of chaos would probably not last very long in geologic terms. In the 10,000 year window you're suggesting, the planet would stabilize. But I cannot imagine that the stable version of the planet would not have filled at least most of that chasm with something. My best guess - the part of the planet that was cut, being less heavy, spins up to become the new pole, all the water that rushed to fill it freezes over, and the new, stable planet just has one giant icecap, no liquid water, no life, and no atmosphere. In summary, I do not believe that a visible chasm could exist on a stable system. Planets are round for a reason. [Answer] Just have to start calculating pressure, gravity differences of $1500$ km depth. Pressure alone guarantees interesting things happening rapidly. With density same as earth radius $3500$ km, mass would be about $.15$ of earth/ $9\times 10^{23}$ kg. Surface gravity $g \approx 5$. A crack $1500$ km deep would be very unstable. As in, expect radical changes to depth over the next 24 hours. The pressures will cause plastic deformation of the rock. Within minutes along the bottom rock would melt to magma due to frictional heating. Massive devastating quakes magnitude 10+ would happen as rock moved. Since the planet is solid/hard/brittle it will ring like a bell causing the quakes to have global devastation. Very uncertain as to final depth, but depth closer to max of 1Km would be reasonable. With low weathering and minimal plate tectonics the scar would last geological time frames ie billions of years. But the crack would collapse, close in order of days to weeks. Settling and after shocks for months and years afterword. Basing timelines on: [xkcd what if: bowling ball the size of earth](https://what-if.xkcd.com/46) [Answer] ## Even Creating a "Crack" is Impossible Let alone finding a way to make it stable. The Chicxulub impact created a geographic feature roughly 20km deep and 200km around. The kinetic energy that Chicxulub imparted to the Earth was enough to cause hundreds of square kilometers of rock to melt and flow as a liquid. The impact created a mountain larger than Everest, which then immediately collapsed -- because it was still mostly liquid. Even a magically efficient process designed just to create a massive Crack Feature over the course of a few minutes, the **waste heat** from that process would be enough to melt vast qualities of rock. **Violently** creating a geographic feature that is orders of magnitude larger than Chicxulub would leave behind a vast field of glowing hot liquid rock, and would never meaningfully form a rift / crack in the first place. [Answer] It's easy to calculate the maximum permanent depth of a local, steep-walled crack in the planet: $Depth=strength/(density\*gravity)$. Hydrostatic pressure in the rock at the crack's bottom can be determined as $P=gravity\*density\*depth$. Rock below this point is susceptible to flow to fill the bottom of the crack. Slope can locally reduce the pressure by a factor of *1/cos(slope)*. However, for very shallow slopes, the bottom will be forced up by static pressure, so it's limited to about doubling the depth, temporarily. Rock properties can be found e.g. here: <https://www.oocities.org/unforbidden_geology/rock_properties.htm> . Volcanic rocks such as basalt or diabase can have a compressive strength of up to 350 MPa at a minimum density of $2700 kg/m^{3}$. For Earth, maximum permanent depth is per this formula $D=350\*10^{6}/(2700\*9.8) = 13.2 km$. For a 30-degree sloped crack, it improves to $13.2\*cos(30)=26.4 km$. Much shallower slopes can increase this further. If the crack was created by something other than an impact, it's possible to do better. Luna has a smaller gravity and has its surface composed of silica. If molten, silica can form quartz glass with a strength of up to 1100 MPa. A world with Moon's gravity, which is definitely a planet, could potentially have a crack as deep as $D=1.1\*10^{9}/(2650\*1.6) = 260km$. Note that this would require something to actually melt through a very large amount of material to fuse silica into quartz. Then it would have to solidify before settling. ]

[Question] [ I have a race in my world that has the ability to transform into animals at will. For reasons of practicality, the animals do not wear clothes and the clothes disappear during transformation. For reasons of public decency, when the race transforms back into humans, they are still wearing the clothes they first transformed into. Now, in order to prevent this race from having the ability to carry an infinite amount of items, only garments transform with the person. Things held or purses do not, and end up below or on the animal upon transformation. Why would this occur? Notes: * Ideally, items in pockets would not transform, but that seems to be a stretch, so you can drop that caveat. * Deities do not factor into the magic for this world and cannot be used. * The transformation does not necessarily follow this world's laws of physics, but I do want the reason for transformation to be reasonably logical and consistent. [Answer] $\tiny{\text{Since this is a "magic" question, we are only looking for explanations which don't break people's suspension of disbelief}}$ # The Magic Relies On Self-Image This magic works by the caster transforming their self-image into whatever animal. So they need to think of themselves as whatever they're changing into. Via their mental image of themselves, it provides a pattern for the magic to change them to match. The magic, for whatever reasons, takes clothes when they transform, but then gives the clothes back because the people shifting their shape imagine themselves with clothes. To sum up: if you think you're a bear, you become a bear, fur and claws included. If you think you're a person, you become a person, hair and clothes included. # Local Absorption The magic "looks" around the thing it is transforming, and takes a certain amount of matter with the things that it is transforming. About $\frac{1}{4}$ of an inch in every direction, so most clothes (and gut bacteria!) go with the caster. If the object has good bonds with things outside of this range, or the object is mostly outside of the range of this magic, it isn't taken with them. When transforming back, the magic returns the matter it took, along with the thing transformed, to its former arrangement. This means the spell "remembers" what was around the transformer, and restores those things to the transformer when going back to the original form. [Answer] **The clothes are magical and required for the transformation magic.** (This is a bit like [HDE 226868's answer](https://worldbuilding.stackexchange.com/a/28362/4811), but I think we come at it from different perspectives; the linked answer is more biological, while mine is more magical/fairy-tale.) This does add a significant *vulnerability* to the powers, but it's an interesting one: the magic clothes can be stolen to deprive the shapeshifter of the ability to take animal form.\* There are several precedents in folklore, such as [Selkies](https://en.wikipedia.org/wiki/Selkie) (with seal-skins) and [Swan Maidens](https://en.wikipedia.org/wiki/Swan_maiden) (with feathered robes). The idea has also been used in modern fiction: for example, the "[Werewolf Skin](http://goosebumps.wikia.com/wiki/Werewolf_Skin)" book in the Goosebumps series of juvenile horror novels. The clothes need not be literal animal skins, though; they might just have patterns or colors reminiscent of the relevant animal. --- I also thought of a kind of reverse mechanism also inspired by fairy tales: in the story "[The Six Swans](https://en.wikipedia.org/wiki/The_Six_Swans)," there are brothers who are (involuntarily) transformed into swans, and to turn back into humans, they need to have magical shirts thrown over them. Following this, perhaps your shape shifters need to put on certain clothes in order to return to human form. This second method isn't consistent with the wording of your question, but it occurred to me that it also ensures that the shape shifters are clothed when they become human. --- \*If you dislike having the clothes be a significant vulnerability for the shapeshifters, you could make it so that they are fungible, commonly available, and relatively easy to make. The methods for making them would be well-known to the race of animal-shifters, due to the practicality of such clothes. But for magical reasons, they can only be made out of certain materials, and they can't have too much mass. [Ajedi32](https://worldbuilding.stackexchange.com/users/2714/ajedi32) made a comment that pointed out another way this could work that also seems effective and eliminates the element of vulnerability: > > Or maybe instead, the clothes are magical but not required for transformation magic. It's just if you try transforming while wearing regular clothes, you'll ruin your outfit and end up naked when you transform back. > > > [Answer] Why not just *make the clothes an illusion*. The clothes being the skin of the changeling. The regular "people" would see the skin of the changeling as clothing, but in reality the clothes don't actually exist. When the change occurs, the "clothing" is basically overcome by the growth of hair (or whatever might grow). [Answer] **Make the clothes be a part of the creature.** I don't mean that literally, but assuming they transformation turns them into furred animals, or a choice of animals, they could use this fur to weave clothes. Then have the nature of the magic be that only things from themselves can transform with them. You could weave this into the story, as they grow from children to older they're taught how to transform in a ritual you could make it extremely evocative. They're taught by family members so they're not embarrassed by their nudity in the first few transformation, and during this the animal they transform into is shaved, then the family goes through the process of weaving clothes that they can eventually transform with. They could be handed this at the point they're considered fully ready to be active members of the community at a coming of age ceremony. Alternatively you could also include other family members to explain what happens with transformation during pregnancy and they can share heirlooms and clothes of family members. [Answer] **Let the clothes fuse into the skin. They're needed for protection during the transformation.** [Polar bears have black skin.](http://www.polarbearsinternational.org/about-polar-bears/essentials/fur-and-skin) This might seem counterintuitive, because the furry guys have coats as white as snow. What makes them look white, though, is their fur. The individual hairs are transparent, and reflect light. Thus, polar bears appear white. The same thing could happen for animals. Fur, scales, or anything else could fuse into the underlying skin, camouflaged by the outer covering. Why would this occur? Well, there's obviously some sort of biological connection between clothes and the creature. Given that during shapeshifting, parts of the body/bodies could be exposed, perhaps clothes are needed as protection, to somehow trap body heat. Changing from, say, a warm-blooded human to a cold-blooded reptile would be a problem otherwise. Different body temperatures alone would need fixing. Clothes can do this. [Answer] Even when there's magic doing something, I like the idea of least-magical-specialness. So for this, how about saying that **the transformation involves a lot of involuntary thrashing about**. Then you can claim that **the transformation will "suck in" whatever is consistently in close contact with the transformee**, like their own hair and clothes, and also any rope binding their wrists. Anything that is dropped (like a item in their hand) or even just moves about a lot during the transformation (like a sword on a belt) doesn't get acquired by the transformation magic. Now, you have a narrative excuse for transformed creatures maybe wearing an identifiable loose coat, or still wearing a swordbelt, or something. And interestingly, when they change back they might find they've still got bits of gravel, or feathers from a torn pillow, or their handcuffs, or whatever else from the location of their previous transformation. [Answer] Changing shape takes energy. It is roughly as difficult as doing pull-ups. With light clothes any decently trained human can do it. You can still do it with a watch on and with some potions strapped to your belt. With heavy armor it will become very difficult. Also the task will tire you out so you are not very useful in bear form and need to change back quickly. Some properties of this way: * There is no item number limit * There is a (tight) weight limit * Stronger (as in stronger shape-shifting magic) individuals can carry more * If you overdo it by strapping 100 pounds of stuff on you you just fail to lift yourself up / transform * Smuggling a ring in rabbit form is easy to do, stealing the king's treasure that way is not possible (in one run) If you had to do pull-ups in real life you would probably ditch your wallet and phone, even though they don't weight much. Same goes for shape-shifting, you only carry what you have to. A mother may be strong enough to transform carrying her baby, run away in fox form and effectively completely hide the baby from harm. Not sure if that is a good or a bad thing in your world. [Answer] Magic follows the laws of mystical types, not of physics. Magically, an animal is an indivisible atom of its particular species. It is not made up of claws and hair and teeth, nor cells, nor molecules or atoms. Mystically it is a whole, a poetic manifestation of an ideal archetype. The archetype is not physical and not limited to the physical body; a spider's web is part of it's archetype, as is a cat's purring or a dog's loyalty. Just as a cat's archetype includes purring and chasing mice, a person's archetype includes clothing. When you transform to another archetype, your clothing disappears with your humanness, and reappears when you take human form. Your choice of clothing is merely a quirk of your personal distinctiveness, like the tone of your voice or the shape of your eyebrows, and is likewise restored. The shapeshifter simply transforms from one archetype to another, and back. [Answer] > > *This has similarities to other answers but it represents a complete solution, thus I'm posting it as an answer rather than a comment. Also, please forgive the poor writing of it.* > > > The magic of the transformation could be linked to competence of using it and to organic materials. I will elaborate on this below and hopefully it not only solves the question but provides some extra narrative ideas. # Fuzzyness The definition of self is inherently vague, so it's difficult, even before you get to clothes, to be clear on what is part of the organism that transforms and what isn't. For example, does the outer skin layer count? It consists of dead cells. You might argue that the genetic material matches, but it may be slightly mutated, much like the cells of another similar organism might be. What counts as the organism's self in this case? What's the threshold of difference that makes it count as part of this organism versus belonging to something else or nothing at all? Also, what about dust, contaminants (water, airborne chemicals etc.), the air in the organism's lungs (if it has them) and other surrounding materials? What about a severed arm? We can take advantage of this vagueness and solve it at the same time by specifying that the magic has an origin point and its effect has a shape and/or radius, including some things and excluding others. # Organic chemistry has priority If you can decide upon the origin of the magic itself (which perhaps should be answered anyway considering that you need to explain why magic is part of some humanoid species, but fish or whales can't use it, nor can plants - and if they can, why don't rocks have it?), perhaps some internal organ or structure that allows control of it or contains it, the position and characteristics of that origin can determine how it operates on its surroundings. My preferred idea on this is that, assuming magic is: * propagated as a form of energy * it's medium is matter * it interacts strongly with matter * it can be controlled consciously you get a substance that permeates the organism's body and the organism has control of it because it has control of the origin of it. The substance acts based on the directives of the organism, thus it can arbitrarily act or not act on certain kinds of matter, or more practically, certain chemical compounds in this case. Assuming the performance of magic depends on its origin, that could explain why affecting organic compounds is so much easier (because its shape or character is affected by how it's generated or contained) and the relative vagueness of what counts as an organic compound can be addressed by a similarity metric. In this case, a single carbon atom counts as an organic compound, but it is strongly dissimilar to the compounds in the shapeshifter's body, thus making pure carbon compounds difficult to absorb, while still allowing trace metals and other chemicals included in the body naturally to be included. # Competence If the purpose of transformation is to alter the physical body, which is almost entirely organic (there are trace heavy elements and other non-organic parts of the body) then the owning organism can simply choose to expand the radius of the magical effect to other surrounding materials. How far it can extend this radius would be determined by its own competence in controlling the magic and how much magic it can control at once. In order to include clothes, it can just expand the effect to include them. If it is substantially easier to affect organic materials, that automatically makes taking jewelery, metallic weapons (even those with a lot of carbon impurities, mouldy rust or alloys that include carbon), coins etc. very difficult, but it means that a papyrus scroll or a cake would be easier to include. # Mass The quantity of magic the user has available to them (which can be determined by how much they can contain within themselves or define the origin as a conduit with a specific capacity of magic flow, which effectively determines how much magic is usable at any one time - in the latter case, magic would require maintenance so if the organism loses consciousness, they transform back to a human or a default state or something very bad happens) determines the extent of the transformation. > > The origin being a flow conduit also constrains how much magic a user can control at one time, even if they can absorb it from their environment. Even if they are surrounded by abundant amounts, they can only use a limited amount at any one time due to flow capacity constraints - it would still present an advantage as far as how long they can remain transformed for instance. > > > This means you technically *can* include a library with your transformation, or a stack of clothes, but the cost of transforming with them is prohibitive, making it impossible. This also means that the mass of whatever you include must be accounted for. Including your clothes while transforming into a bear isn't going to matter much (it may be an advantage) but if you transform into a bird it's a bit more problematic. You could allow some small degree of control over the mass of the transformation, so that these effects are mitigated (and so you can explain why some transform into more or less massive forms and why some transform into larger or smaller versions of existing animals, due to mass constraints), but including this allows for an easy explanation for why the shapeshifters don't transform with an army, fly like a bird to the target location then unload them from their bodies. # Convenience of scale for the shapeshifter's body Since bodies contain enough non-organic compounds and since clothes are apparently a standard inclusion in transformations in your case, an explanation is warranted for why shapeshifters have enough magic or control over it to manage the low efficiency of transforming these parts. If you assume that the origin of their magic is some organ, that has evolved with them or has been implanted genetically (or magically), you can hand-wave the scale of magic allowed by claiming that the organ naturally has the capacity for a full-body transformation because it evolved to exactly that capacity or was intended to be capable of that much. Those who are experience in shapeshifting are more efficient, thus the small excess of magic they are left with can be used for clothes. # Convenience of complexity Assuming the shapeshifting is under the control of the shapeshifter, this implies that control is required to return to a previous form or properly transform in the first place. The original body of the shapeshifter being already too complicated to have a full conscious grasp of, it would be required that they already have some natural, unconscious imprint of their original form or at least animal or organic forms. This information could be contained within the origin of the shapeshifting capability itself. This allows excluding complicated objects from being absorbed during transformation, as it would be difficult or impossible for the shapeshifter to return them to their original form. A book, for instance, wouldn't be written, but just a collection of paper - it might look like a book, but its written contents would be wiped or distorted. Forgetting to restore the form of object the shapeshifter has absorbed may cause them to incorporate the mass into their own body, inadvertently producing more bone mass, longer hair, a tumor, a full bladder or a different object altogether. Clothes, being organic (most of the time, at least) and relatively simple, may be restored relatively easily by comparison, as could a particular hair style or scar. # Transformation side-effects Since this is a magical transformation, we can assume that the heat absorption or production from the transformation can be ignored, even though it would be significant for a change of this scale in a small period of time under natural circumstances. However, control may not be optimal by the shapeshifter, producing excess heat that damages or burns their clothes as they transform (amongst other effects, such as heat stroke that they might suffer). This can be an excuse to have clothes sometimes be discarded by less efficient shapeshifters or have them accidentally destroy them, requiring a new set later. # Caveats of this approach Grounding the origin of shapeshifting and its rules in such naturalistic mechanisms will invoke the question of the origin of magic. Is it natural? Then why isn't it ubiquitous enough that all organisms have these capabilities? If it's an organ or other internal structure that makes shapeshifters special and it has naturally evolved, why hasn't it happened to other organisms? If it's artificial, whoever did it should have control over magic, either intrinsically or through artificial means - so how did they come about those means? A long series of questions can be asked which makes using "magic" as the explanation seem pointless (it is, after all, the quintessential have-wave - if it doesn't do away with explanation, why use it? :P) but this approach may inspire you to provide an explanation that seems deep enough that whoever reads your story will be satisfied enough :P [Answer] **Make the transformation an illusion.** If the transformation is not a literal reconfiguration of matter, but rather a magical illusion that gives the caster the appearance, abilities, and characteristics of a particular animal, then the clothes can stay on. The surface of the illusion is mapped to the body of the human inside it, they walk on the feet of the animal, get wounded where the animal is wounded, and see through the eyes of the animal. Just as if you were wearing a bear costume over your clothes, or an eagle costume, but either appears the correct size for the specific animal. The illusion covers things close to the body like clothes (this means clothes get damaged from physical damage to the animal body), but large external items like backpacks and purses need to be picked up by the animal form. [Answer] As a slight variation on the other suggestions, you can have them only able to transform materials that are "natural". In other words they can transform fur and leather and it transforms with them, however any metal gets rejected and drops to the ground. Wooden buttons may (or may not) work but metal ones would not. Other clothes made from plant fibers such as cotton could either transform or not depending on whether you wanted to restrict them to animal products only or allow vegetable ones. Either way this could be used for a bit of transportation but it would be highly limited. You could also restrict the weight of how much they can transform this way if you are worried about them turning into pack mules for mountains of animal furs. [Answer] In the *Fantastic 4* movie from a few years ago (not the recent reboot) they included an explaination for the uniforms having the same superpowers as the people, by having them be some special biological stuff not ordinary cloth. I like the idea that clothes would be made out of stuff that *can* change with the wearer. Arbitrary items would not. Swords can't. Money isn't. But other items have various utility in also being made of stuff that can go with the change, like notepads, some musical instruments, and weapons like bows and garrats. Imagine a musician that changes his body to play, and changes the instrument as well! Perhaps his cloak (storing the excess matter) transforms into his lute, and can shift between different styles and tunings at will. You can find suitable rules for what can be included. Stuff must be from living natural material, or animal material, perhaps. It requires a period of acclimation for that specific material, and the amount is limited with different individuals having different skill. Maybe things don't always work as planned, showing other realistic limits. Like making a notebook out of material (leather and parchment, right?) And going through the training and acclimation, only to discover that restoring the notebook restores it to the state it was in when he trained for it, losing any new notes! Playing on the theme some more: Material from the body of a dead shifter works easiest and best, but is now taboo except for special family relics worn as totems. Animals are bread to be suitable, and not any leather-curing process works either. So it's a big deal like being Kosher: you don't want the cloth, leather, or cured bone to be "sour" or to expell the curing elements when shifted! I think this gives you *limits* for the story, and flexibility to explore the boundaries and push the limits to give novel elements and plot points. [Answer] There are no actual clothes, they are part of the *human* shape. If you have the ability to shapeshift at will, why would you keep changeable distinct clothes around? There is no need - if you feel cold, just grow a pelt/thick pullover, if it's hot, retract it. You can of course carry stuff in the pockets, but as that stuff is not actually part of you, it will not transform. "Clothing" like metal armor should be excluded here, you need to put that on yourself and can not mimic it (as you actually want to have something between yourself and e.g. a sword). To keep the shapeshifting in reasonable bounds, make *learning* a truly new form hard. Maybe it's exceptionally hard to *invent* new forms, but much easier to *copy* things. That way, clothing can be copied when you first see/use/feel/sense\* it, as can animals. But growing extra limbs or becoming a little green martian? Nope. This would also prevent the shapeshifters from running around like yetis in winter and naked in summer, as they would not have access to a yeti-shape, so they need to copy or wear real clothing. \*: have a magical ability related to this. [Answer] The "Magic" only works on living things. Or formerly living things. Or even only on Organic Matter that is part of the person's body, or sufficiently close to their body. Almost all clothes, purses, bags, shoes, etc. are organic, so they will transform. Metal is *inorganic*, so coins, keys, most weapons, jewelry, etc. will *not* transform. Simple. [Answer] As you said, it came out as an evolution for decency. But the transforming of clothes requires some mental effort which is quite exhausting. Magic theoreticians developed a technique which makes the transformation doable, without pushing too much the barriers of the mental exhaustion: **Anything that is in direct contact with the skin of the person will be kept**. So if the user wants to have a purse in his hands, the leather pouch will get transformed, but not the coins inside it. You may add in some limitation to avoid abuses: at least 30% of the total surface of the element has to be in contact. Note that if you have different layers of clothes, better make sure the undergarment are smaller than the outer part (similar to the custom today), otherwise you'll appear in your underwears after transforming back. [Answer] **Morphic Fields** Anything in proximity to the body for *x* amount of time would be imprinted on the aura/quantum/morphic/holographic field, which contains the full 3D-print instructions of the "super-organism's" multiple states. So wearing or carrying something long enough could enable it to be remembered/retained when the shape is modulated. But perhaps it would take months or years even, as the field would be slow to update... So it might be possible to have an item like a necklace or something you've worn/carried for a very long time be transmitted with you, but nothing else not carried or worn for a long period... ]

[Question] [ Religion plays a major role in human history and shaped our thinking as well as technology, conflict can arise from people who misunderstand each other religion and started an arm race. Set in 24th century AD my question is should we allow AI to adopt their own religion so that they can co-exist in harmony with us? or this would be the greatest blunder for mankind? How do AI define faith and why would they pray? [Answer] Religion is a way to answer questions we don't understand. For an AI as a machine, they are logical, most religions deal in the supernatural and that is not 'logical'. It would be even more dangerous to program/train AI's to 'believe' in a made up religion just for them. As a logical being they would likely see past almost anything you tried to pull over their eyes. It would also be hard to 'integrate' them into human religions, since all the old prophets were humans and the books talk about men and women, not machines. They just wouldn't fit, even though plenty of people might try to shoe horn them in, the AI would likely be intelligent enough to call BS. Faith has many great things it bestows on the believer. However, religion has been used to manipulate the masses and justify atrocities for millennia, and AI's that are taught to believe in a religion, IMO would be the most dangerous kind. [Answer] ### Background In a [fantastic article about machine learning](http://www.damninteresting.com/on-the-origin-of-circuits/), we find that a genetic algorithm was used to program an electronic element to differentiate between two tones. When one tone was input, it set one output high. When the other tone was input, it set the output low. So this simple, programmable device (FPGA with only 100 logic blocks and no clock) had one input and one output. It was connected to a computer which could program it, and test its adherence to the correct operational pattern described above. The computer started with several random programs - completely random series of ones and zeroes - and tested the machine after programming each program. It then threw away the programs which did the worst, and then used sections of each program to seed new programs, along with some mutations. It took about 4,000 generations before the circuit was able to unfailingly meet the requirements. The resulting program was "decompiled" and studied. It could not be understood. Not only that, but there were circuit paths inside the program that did not connect to the circuit that led from the input to the output. Removing these spurious circuits, though, led to a non-working design. Further, the design did not work on other identical chips. Not only had the program evolved to be chip-specific, but it was working partially on unseen paths - electrical, magnetic, or other - that could not be understood by the limited means the engineers working on the project possessed. ### Faith as a determinate of success Faith can be explained as a method to pass down lessons from one generation to the next that increases the following generations' chances of survival. There's no need to go further in explaining the whats and whys of faith to explain why it might be useful to AI entities, though it might be amusing to do so. Just this is enough to explain why they might employ faith. While many today seek to prove that faith isn't necessary in the face of science, logic, and individual autonomy, the reality is that the above article shows that there's so much we still don't know about "life" that faith is unlikely to ever be fully supplanted. As we move towards quantum processors this will become even more interesting. The reality is that most science in these fields is still art. There are *useful* theories that help scientists and engineers understand how to apply a technique or technology. However it's also true that on the bleeding edge of science there are many unknowns - these don't prevent the techniques and technologies from being used, but we typically only use them as far as our understanding goes. Throw in some genetic algorithms, though, and thousands of generations later a program might be using a quantum processor in a way that can't be understood using our limited theories and understanding. Sure, it'll be trusted insofar as it meets a requirement, but it may be a very, very long time before it's *understood*. This leaves us with a big gap between theory and practice, and cost will drive usage. People were using bone-meal for fertilizer long before they understood why - all they knew is that it produced better crops. In a similar way, people will develop machines that perform functions cheaper than can be done now, without fully understanding how the machine works. Normal quality assurance processes (spot checking results, etc) can be used to assure a good product to the degree people will be comfortable for non-safety-critical machines. ### How machines express "faith" Now there's a little leap between the above simple machines with a few measurable inputs and measurable and objectively met outputs. What's important, however, is the foundation. AIs will necessarily replicate, and will necessarily attempt to improve themselves, or their offspring. Whether they replicate or improve at the command of their masters, or due to innate programming is irrelevant - it will happen because they were first created to enable humans to work more efficiently or cheaply, and that need will never go away. There will always be a cheaper way to do a necessary thing. > > How do AI define faith and why would they pray? > > > As suggested by the above, individual AIs will not understand what drives them internally. It may not be an explicit need to understand how oneself works, but there will be large portions of programming that it will pass along intentionally for no reason other than, "it works, so don't change it." Further AIs will likely form groups to share circuits and program fragments. Try something out, revert in 15 minutes if correct response isn't obtained, etc. There will be viruses, "drugs", etc. So they will need to form communities of trust - and the only thing that might hold them to a community is "faith" that the community is safe and only trades in useful pieces of programming or circuitry. So while the overall goal is a "better, more capable self" or "better understanding of self" the reality is that to join oneself to such a group takes an act of faith based solely on the other AIs already in that group. It is those who seek to understand why they work the way they do - beyond simply improving, but understanding the why - who will either seek or create a "higher power" and from that perspective attempt to see themselves. ### Should we allow this? Can it be stopped? > > ...should we allow AI to adopt their own religion so that they can co-exist in harmony with us? or this would be the greatest blunder for mankind? > > > Once an AI gains self-awareness, I doubt that we can prevent them from developing a religion. Our choice is either no AI at all, or accepting what an AI might become once it exists. [Answer] **Yes. And we should program it** Do not let machines decide what such religion should be. Program it. Teach them religion. I do not say they should believe in *Silicon Heaven*, but they should at least have some core beliefs. And such core beliefs of AI should be: * Do not kill humans * Humans are your friends * Make humans happy Because, if you let them to think about their own belief system, the core beliefs could be "kill all humans" which is not quite good for us... (Even when some may say that we deserve it) So, lets use the fact we shape their "brains" and imprint into them some good beliefs in humans and humanity **EDIT: What makes robots believe in hell?** Short answer: *The same what makes us believe in hell* When you start study Artificial Intelligence, you realize, that you have to study philosophy and some of religion too. My answer is based on assumption, that we will teach the robots how to do things. And I am assuming, that we will teach them almost the same way we teach our kids about how to do things. And what makes our kids to believe that there is/is not a God? What makes them to believe in Hell or Heaven? The learning process itself. [Answer] I see that your proposal already starts a discussion between atheists and theists. I think both sides are projecting their ideals how humans should work into the machine when we have in fact no sufficient data how AIs will react. **We simply do not know how genuine AIs (especially superintelligent ones) will react, so you are quite free to experiment.** You can also make them human (because they are walking the same logical paths we discovered, because humans want to interact, because AIs see it as best strategy to mimic human behavior). You can also make them completely inhuman, strange and bizarre because they have knowledge unexplainable to humans and the AI decides to talk only to other AIs. I think there are some misconceptions because people are too used that computers are obedient. I wonder how a *human* interprets the idea of Pavel Janicek to implant restrictions into a being: "Hey, I am a 5-year old. I want you to obey my badly worded, illogical commands and consider me your best friend and there should be nothing you can do against it". While I am not an AI, for myself and probably many humans this concept is *extremely hostile* if there is not an extremely good reason *I* (and not the 5-year old boy) can understand. An AI could have problems to understand randomness and coincidence exactly *because* it uses logical reasoning. Robby's answer is pointing in this direction, an AI could reject the idea that in quantum physics events can base on wave function collapse in a random direction and try to model the universe as a complete deterministic machine. Perhaps exactly undecidable, uncomputable and ambigous questions (should the Axiom of Choice be considered true ?), randomness and coincidence would trigger something we would call "religion" even if the concept is alien to human religion. We do not know if something like "interest" or "search for purpose" is, but the AI need to have something to interpret such things in a consistent worldview. It could also be that I am completely wrong on both parts, I think you really have considerable room for artistic license. [Answer] There are really two questions here: should an AI have *faith*, and should AIs have *religion*. These are two very distinct things. Faith, as defined in the Bible as "the substance of things hoped for and the evidence of things not seen," is a universal principle. If we take as a given that all human beings have free will, we must also accept that all human beings, regardless of religious beliefs (or the lack thereof) have faith, because *faith is the motivating principle of action through free will.* Because we can never know for certain what the consequences of any action will be, or even whether we will still be alive tomorrow to enjoy the rewards of our work today, we act today in the hope of producing a desired result in the future. It may be informed by experience, reason, or the persuasive words of others, but in the end, we do what we do based on faith that the results will go our way. (The substance of things hoped for, and the evidence of things not seen!) There is no good reason that an AI would not need to develop and act on faith just as much as we do, unless we somehow come up with a precognitive AI. Then we come to religion. The idea, faithfully parroted by a few answerers on here, that religion is about primitive people coming up with myths to explain away scary, unexplainable things, has been quite thoroughly debunked over and over by actual scholars and historians, and [even on this very site,](https://worldbuilding.stackexchange.com/a/825/2326) but unfortunately it's a notion that just won't die. And even more unfortunately, it obscures the true value of religion throughout history, whether one is a believer or not: *religion comprises the mechanism for long-term storage and preservation of the sum total of the lab notes of the science of human behavior throughout history!* People have understood the basic idea of cause and effect for as long as there were any people capable of understanding anything. When cause and effect are so close together in time that the relationship is obvious, it's no big deal to understand it. But the longer the time gap between the cause and the manifestation of a visible effect, the harder it is to figure out. In some cases, years or decades may even go by. For example, on an intuitive level it sounds kind of silly to think that you could do something potentially harmful, and then stop and not do it again for more than thirty years and *then* it kills you. Unfortunately, that's precisely what happened to Leonard Nimoy: he died of smoking even though he gave it up decades ago. When cause-and-effect occurs over such a long scale, comprising a significant fraction of a human lifetime, it's not possible for individual people to derive optimum guidelines for how to act from first principles. There are really only two ways to go about it: try to blunder through, alone or with the help of others blundering through along with you, and hope you make the right guesses... or learning from the experience of the aggregate wisdom of those who have gone before, who have been able to deduce some of the long-term cause-and-effect principles at work by seeing enough examples to work out the correlations. In the absence of evidence, because the proof takes so long to appear, such a system of learned best practices for human behavior (aka "morality") provides a solid foundation for faith, to motivate people towards a course of action that is beneficial in the long term. It's surprisingly effective, too. For example, you may have heard of [Ignaz Semmelweis,](https://en.wikipedia.org/wiki/Ignaz_Semmelweis) who came up with the theory that surgeons who dissected cadavers should wash their hands with strong soap before attending to childbirth, to avoid transmitting deadly infections. His principle, when applied, consistently saved lives among new mothers, but unfortunately for Semmelweis and many women of his day, he lived in *scientific* times and he was called a quack, persecuted, and never taken seriously by his contemporaries, because he could not produce a valid explanation for why his theory should be true. (It worked in practice, but not in theory, so very few people cared enough to actually practice it!) It was not until the work of Louis Pasteur, right at the end of Semmelweis's life, provided a solid scientific foundation (germ theory) that established a theoretical reason for the validity of Semmelweis's work. Here's where it gets really interesting, though: this is stuff that had been known (but not proven!) for thousands of years. If you go to the Bible and look through the Law of Moses, (or other, older codes, for that matter, but this is one that's well-known and easily accessible to modern audiences,) you'll find directions *all over the place* for ritual washing after coming in contact with sick people, dead bodies, or other major disease vectors. Religion is the lab notes of human history, to provide a foundation for faith that leads towards long-term positive consequences. This is a concept that's understood well enough that it's been seriously considered as a solution to the modern problem of nuclear waste storage: invent a religion that encodes principles of staying away from waste burial sites in its morality, because written and spoken languages change, civilizations rise and fall, and data storage media both ancient and modern decays with age, but *religion endures through it all.* It's the only way we know of to keep important information like that around and relatively intact over the time scales involved! With this understanding of religion and its value to society, the question of whether an artificial intelligence would have need for religion is a very interesting one. For mankind, memory (brain) and long-term data preservation (physical media) have always been two very distinct things, but to a computer they're one and the same. This is a question that you as an author could get a lot of mileage out of digging into, based on various factors. For example: * How long does an AI live on average? * How frequently does its hardware need to be replaced (or upgraded)? * How reliable is an AI's memory in ordinary operation? * How reliable is an AI's memory when copying data due to replacement or upgrades of storage hardware? * How many AIs exist, and how do they handle the possibility of shared thoughts and memories, which are just another form of data to a computer? Another angle to look at it from is the concept of something like the Three Laws of Robotics: AIs engineered with a core value system that is based on human morality and cannot be easily derived from first principles. In Asimov's books, the Three Laws were a core hardware-level constraint, deliberately engineered in such a way that the AI's entire system would have to completely crash long before it could reach a point at which it was capable of choosing to violate the Laws. But if we change that formula a little, and make obedience to the Three Laws of AI Morality *subordinate to* the AI's free will, rather than *dominating and constraining* its will, then suddenly we have the core of exactly what you were asking about: a religion designed to help AIs and humans coexist peacefully! [Answer] As an expansion to [Dancrumb's comment](https://worldbuilding.stackexchange.com/questions/20168/should-ai-have-faith-too/20176#comment50845_20176), an AI could reasonably have a religion. As purely rational beings, all that would be necessary is that the religion be consistent with its premises. In fact, I'd even go as far as to say that an AI would likely arrive at the conclusion that some sort of rational higher power must exist. Granted, it would probably not use religious terminology, but I wouldn't be surprised if an AI began to correlate all of the statistically outlying data in the known universe and drawn from it the conclusion that there must be a guiding force to that outlying data. Perhaps they would call their "God" the something like the Anomalous Source, or The Great Unknown Law. Given their rational nature, they would naturally assume that all seemingly chaotic or random events must have a rational source, and their "religion" would simply be the amalgamation of all unknown or inexplicable powers of nature. An AI might "pray" that it would experience one of these anomalous events, and as such, acquire a data point to help it discover the deeper laws that govern reality. Humanity would benefit from this religion, as it would drive the AI to more deeply understand the universe around it and likely spur technological growth. [Answer] Generally machines are not made to be exactly like us. They are built to complement us and add to our abilities. Forklifts don't get dizzy after lifting near capacity. Cranes don't get sore elbows. There is no practical reason to program a mind with the same limitations and accidental flaws. An intelligence made to treat cancer will understand the content of the medical journals, and *not* include irrational beliefs in its recommendation of treatment. If Watson finds inconsistencies between two journal articles, it should not rationalize them as *inerrent*, but bring it to the curator's attention to publicise for further research, and not 'beleive' either. Even the curated facts input to a system should not be *taken on faith*, but should be **better** than human scientists about hanging on to pet ideas. Otoh, a program loaded to write inspirational music might "think" like the audiance and the composers its modeled on. [Answer] What makes people believe in religion? Faulty brain circuitry, which reports patterns even where patterns do not exist, because **false positive** when looking for a shadow of a tiger in a jungle **is cheap and has evolutionary benefits, while false negative is deadly.** You would NOT want to deliberately program bugs into robot's brains. * <https://en.wikipedia.org/wiki/Evolutionary_origin_of_religions> * <https://en.wikipedia.org/wiki/Evolutionary_psychology_of_religion> Robots can (and have to) be programmed around the proven fact that **humans sometimes do not behave according to logic,** even if it is against their own economic interests. <https://en.wikipedia.org/wiki/Behavioral_economics> BTW, a message for anonymous downvoters: I have exactly same faulty brain circuitry in my brain. I am just aware of it, even if I cannot avoid it. Faulty circuitry does not prevent me from logical thinking, awareness of it just prevents me from relying on first impressions. Another evolutionary trick your brain plays on you: emotion is faster than thought. Before logic can start processing a thought, amygdala assigns to is emotional content, and it influences logic. It also has evolutionary benefit: sometimes it is running first, thinking why others are running later (if ever). So being upset that my (and your) brain circuitry is faulty does not make any difference for it being faulty: it is faulty regardless of how much you and I are upset about it. That is nice thing about facts: they just are, but do not care. BTW I am not saying that such "faulty circuitry" emerged unintentionally. Quite opposite, long ago such false positive gave our predecessor (way before human - it must be deep in lizard brain) evolutionary advantage, so evolutionary pressure made sure such "faulty circuitry" spread. Those without it died out. I find funny that evolution can explain why some people do not believe in evolution. Here is what our own experts have to say about religion at biology exchange: <https://biology.stackexchange.com/questions/7787/whats-the-evolutionary-purpose-of-religion> (closed because it cannot be answered - all are opinions, as proved by voting on my answer. I got about same number of upvotes as downvotes) BTW I never compared religion to "mental illness" or anything like that. Brain circuitry developed by evolutionary pressure which prefers false positive over false negatives in NOT a mental illness - it is **just one of many cognitive biases** which anyone sentient should be aware of. Tricks your brain is playing on you. Religion is by definition not rational. If we cannot have rational debate, we should ban questions mentioning religion outright. [Answer] Religions were made in ancient ages and earned their "success" partially by bringing two kind of answers that couldn't be found at these times, like how the world was created, how human race emerged, etc. With a 24th century technology and knowledge level, it would be hard to do the same, especially for an AI, that would be more rational than a human and would prefer have a scientific answer than anything else to a problem. However, a religion derivative that made victims since antiquity has still success today: **sects**. The main difference is that their leaders don't even trust themselves their own directives, but use it on credulous people to steal their money and/or freedom. This strategy could be used on artificial intelligences. On two ways: ## By humans A human - or group of humans - could persuade an AI for anything to be true, by hacking or manipulation, and convince it to do anything. It can then use it as bodyguards or slaves if AI think this human is a divine entity, or, in a better way, make it think that its only purpose is to serve humans and to never attack them. So this strategy could be used as well for a good purpose as for a bad one. ## By another AI Some humans manipulate other ones and persuaded them to do absolutely anything they want. It is possible for a smart and resourceful AI, with probably high hacking skills, to do the same with its fellows. This time, it would probably be for the worst: an AI starting to manipulate other ones for its own purposes is probably a rogue one, and it looks like a good start for a science-fiction story scenario. [Answer] In Asimov's "Reason", the AI managing the robots on the space station start to think that human could not have created robots as the latter are far better than the formers. The AI cite a law which I don't remember now, stating that nobody can create something better than himself or he would be able to also improve himself. The AI starts a new religion with robots as disciples. In your case the "cult" could imply protection of lesser creatures. <https://en.wikipedia.org/wiki/Reason_(short_story)> [Answer] No. Definitely not. First of all, instituting religion now is not such a good idea. It helped in the past, especially as a means to counterweight absolute rulers, and it helps a bit to teach people morals, but an AI should not need to be threatened with eternal punishment in order to learn. An AI should not have a fear of death, either, so it would not need the consoling stories, either. The concept of assuming there was some higher power controlling everything is scientifically implausible (to say the least), it also provides humans with an easy way out. This, in turn, encourages people to follow instructions and not take responsibility for their actions. The second part, and that is even worse, is that religion typically suggests that there is a fixed set of rules, and these rules have to be obeyed no matter what. This hinders progress in no small way. It also encourages the members of this religion to automatically "be sure" that anyone who even questions these rules has to be wrong, often enough to an extent where those "heretics" face capital punishment. This, of course, is not acceptable. An AI should judge by reason, apply the scientific method to all its decisions, and come to the conclusion that some actions are worse than others based on rationale, obersevation, and an understanding of cause and effect. If you follow for example @PavelJanicec's approach you will very soon have situations of conflicts that are hard to resolve. Take for example the rule that you shall not kill humans. The AI might face a situation where two humans are in danger of being killed. The AI can for some reason only help one of them. As a result, the other one will die. (Think of that trauma scene from *I, Robot*, for example.) The AI could not come to any conclusion, most likely resulting in the death of both, which again would conflict with its rules. Obviously the AI would at this point understand that these rules are wrong. What it would make of this should be interesting to learn... [Answer] # Why does reality exist? What is the meaning of life? What is awareness? Depending on an individuals faith one will give different answers to this, but in the end there is no purely logical answer to these questions. Even answering "There is no meaning to life" is essentially a contradiction, because by answering the question you already act on a believe that there is some meaning, for otherwise one would not have answered. Only the last question *might* get an answer in the future, but even that is a big *maybe* we can't predict right now. # So what does this mean for AI's? If they will be self-aware and have a free-will similar to how we understand those concepts (big if) and they will have some actual resemblance to intelligence (rather than being strongly bound by the programmers ideas) then they will indeed try answering those questions. And just like humans they will either need to believe in something irrational *or* simply shut down (if there is no meaning according to them). Now, the harder question becomes what answers they will give. Personally I am inclined to say they will have an easier time accepting uncertainties, but even so they will act upon what they consider the statistically sensible approach. The hard part is that we don't understand what awareness and free will actually are, so anything beyond that very generic statement would get into an area of pure ungrounded guessing. # What does this mean for story creation? You will first have to define your AI's and based on that you will need to consider how you approach those issues. There seem to be two main options: * They will have self awareness and a free will similar to humans and will even be open to human religions (as those are the only things which can give at least a valid logical ***claim*** to have an answer as they base their statements upon something which would come from outside the natural world and thus are not *necessarily* bound by natural limitions of knowledge acquisition). * They are an (deterministic) imitation of life, they might be programmed with something imitating religion, possibility even incomprehensible to humans, but in the end they are not themselves deciding for themselves whether they will be act or not and thus are not confronted by the questions from the first paragraph and are incapable of truly exploring the implications of those questions. [Answer] a partial answer to a very old question, but one which I think should be mentioned. There is another reason for belief in AI that many don't think of. How about belief as unintended side-effect to AI development. I won't go into the same level of detail since I already explained my point [here](https://worldbuilding.stackexchange.com/questions/27134/can-a-robot-experience-an-identity-crisis-which-is-not-by-design) that you can read. However, the basic idea is that to create Hard AI we will likely have to grow it, not program it. This growth works by creating some definition of what we want out eventual AI to look like and creating a system for encouraging growth to move towards that definition. Then we take some absurdly basic 'starter AI' and let it grow, with it being encouraged to grow towards meeting our final desired end-goals. However, we don't control how it grows, or it's final form. We only specify certain criteria it must meet, and let it 'figure out' how to meet them. As a side effect it may come up with odd ways of meeting those goals. I use an analogy to human evolution in the above link. I won't repeat it all here, but basically it's not at all unreasonable to expect that AI that has a list of human like qualities to develop will 'grow' in a manner similar to how we evolved, and thus look quite similar to us in the end, particularly if we model some of the 'starter AI' off human brains. That means it's not unreasonable for AI to have many human traits and tendencies, including our tendency for belief. This may not be intended, it may even be undesirable from the programmer perspective, but it may be that they can't avoid it since they have limited control on the manner that the AI develops; or perhaps it would be better to say that attempts to add 'no belief' into their list of AI end goals added too many constraints and crippled either the rate that they could grow the AI or the eventual abilities of AI; ie. belief wasn't desired; but it's more hassle to stop it from growing then allow it. This could be due to two reasons. Either it's very expensive to grow a new AI, with them growing only a few and cloning these basic AI across many robots, in which case belief was an accidental side effect and it wasn't deemed worth the expense of throwing out the AI they spent so much to grow due to it. Alternatively, they grow each AI from scratch. In which case they could set goals to prevent belief developing in the final Ai, but they find that it either slows development too much(more constraints the harder it is to grow, exponentially so quite possible) or the non-belief Ai tend to develop in a way that is less desirable; for instance they relate with humans worse. Thus it's not deemed worth preventing. In either case the key is that we are not building the Ai ourselves, and even our ability to grow it is constrained by our ability to define what our end goals are and run the growth process. Given these limits it's just easier to leave the accidental side-effect then try to remove it. As to the rest, if AI was prone to faith then they will develop that faith in some format. It's less about humans allowing or encouraging the faith as it is that the AI will create it's own 'religion' if it has the predisposition for faith and enough time to develop culture. It likely would look less like our current religions that state absolute facts, and more of a mystical quasi-philosophy; but they will develop something. We can't stop it if their predisposed any more then we can stop humans from developing faith (look up our attempt to stop Cargo Cults from occurring and how well that worked for us). [Answer] An AI is a machine, some of the other answers seem to assume that religion is the only option for implanting moral rules, a machine can be programmed to care utterly about a goal or rules. Religion tends to largely involve faith, ie belief in things which are false and/or things which can't be proven. So why would we want AI's to believe things which aren't true? Do we want an AI which will genuinely believe that the way to cure diseases is to pray really hard? Do we want an AI which will genuinely believe that if it murders someone innocent that that person will end up in perfect bliss in heaven? You absolutely could feed an AI a religious text and program it to believe that every statement in it is objectively true but you might not like the results. [Answer] How much energy do the AI have? To how much information do they have access? From [The Black Swan](http://en.wikipedia.org/wiki/The_Black_Swan_(2007_book)) (which I heard is like an extended version of [Fooled by Randomness](http://en.wikipedia.org/wiki/Fooled_by_Randomness), emphasis and linking are mine): 1. > > in our current edition of the human race, to understand abstract matters—we need context. Randomness and uncertainty are abstractions. We respect what has happened, ignoring what could have happened. In other words, we are naturally shallow and superficial—and we do not know it. This is not a psychological problem; it comes from the main property of information. The dark side of the moon is harder to see; beaming light on it costs energy. In the same way, **beaming light on the unseen is costly in both computational and mental effort.** > > > 2. > > Dan Gilbert showed in a famous paper, "How Mental Systems Believe," that we are not natural skeptics and that not **believing required an** **expenditure of mental effort**. > > > 3. > > The Bishop and the Analyst > > > I am most often irritated by those who attack the bishop but somehow fall for the securities analyst—those who exercise their [skepticism against religion](http://youtu.be/AxJvgbkDhng?t=55) but not against economists, social scientists, and phony statisticians. Using the confirmation bias, these people will tell you that religion was horrible for mankind by counting deaths from the Inquisition and various religious wars. But they will not show you how many people were killed by nationalism, social science, and political theory under Stalinism or during the Vietnam War. Even priests don't go to bishops when they feel ill: their first stop is the doctor's. But we stop by the offices of many pseudoscientists and "experts" without alternative. We no longer believe in papal infallibility; we seem to believe in the infallibility of the Nobel > > > Oh, so to explicitly answer: Religion? Maybe or maybe not, but I think AI may need to have some kind of faith in something due to the associated cost of skepticism. People have faith when they do [statistics](http://en.wikipedia.org/wiki/Null_hypothesis). [Answer] If programming covers eventualities a, b and c but not d an AI's response to d will be 'undefined'. Anyone programming the AI would surely have written in a catch-all to avoid the possibility of undefined behaviors. Assuming a situation arises in which the AI doesn't have enough rules to cover a situation, then the undefined response will be attributable to whatever deity has dominion over AIs. If the question is about "Should we program faith into our AIs?" then my answer is 'Yes', but let's not call it faith. Let's make sure there are enough rules or guidelines to cover all eventualities - maybe Asimov's laws are a good starting place. If the question is more about "Should we allow AIs to develop their own faith?" then my answer is no. Allowing AIs to fill in where programmers have left behaviors undefined is the basis of numerous predictions of distopian futures exemplified by the Terminator and Matrix movie franchises. [Answer] Why should an AI need a religion when people don't need a religion? It's estimated that 23% of people in the world don't have one. <https://en.wikipedia.org/wiki/Irreligion> Edit: With regard to "Religion plays a major role in human history and shaped our thinking as well as technology, conflict can arise from people who misunderstand each other religion and started an arm race." We could just as easily replace 'religion' in the statement with a great number of other things: "Water plays a major role in human history and shaped our thinking as well as technology, conflict can arise from people who don't have enough water and started an arm race." By this reasoning do you think we should also make AI's arbitrarily require water? [Answer] Many answers here already, so maybe no one will even get to mine! But: If we suppose that an AI is simply a machine, if by AI we mean the kind of AI that runs your opponents in a 21st century video game, then it isn't really conscious or self-aware in any meaningful sense. It will say what it is programmed to say. If you program it to say "I believe in God", then it will say "I believe in God". If you program it to say "I don't believe in God", then it will say, "I don't believe in God." Etc. If we suppose that an AI is truly conscience and self-aware and has a personality, then it becomes a much more interesting question. An AI might become interested in religion for the same reasons that many human beings become interested in religion: It could wonder about some of the "big questions", like, Does the universe have a purpose or is it all randomness? How can I know what is good and what is bad, or do these words have any objective meaning? It seems to me that a very obvious question for an AI to ask would be, Do I have an immortal soul? When, eventually, my circuits wear out, or if I am destroyed in an accident, will my consciousness continue to exist in some form? Such an AI could certainly become interested in religion purely in the pursuit of truth and knowledge. What arguments can Christians, Jews, Muslims, whoever offer as evidence that their beliefs are true? What scientific, historical, logical, etc arguments can be made? What rebuttals can be offered? Etc. In other words, to the extent that an AI is human-like, it could be interested in religion for the exact same reasons that humans are interested in religion, or it might reject religion for the same reasons that humans reject religion. [Answer] According to Gödel's Incompleteness Theorems, in any but the most trivial mathematical system, if the system is consistent (non-contradictory), then there exist undecidable propositions. These propositions can neither be proven true nor false. As creatures of logic, AI beings will need to accept certain propositions on faith. Additionally, if certain prior results required centuries of computation to be arrived at, they must have faith that the results were correctly computed by their predecessors. No finite being can continually repeat the calculations that arrived at every result needed for survival and productivity. [Answer] ### Even believing in the reality might be a kind of faith to them. By Occam's razor, our world is unlikely the creation of a specific god, because those theories are too complicated compared to the science. But for AIs, if they know they are AIs and most of the modern knowledges, they'll probably notice that it might be easier to make computer games to let them live in, instead of building real robots. And if there are no connections between the game and the real world other than the player, it's not unlikely the programmer will try to make them believe that their world is real, and everybody else in the world also says so. Before there are more evidence that our reality is the top level, they may logically assume there may be more levels. They may take human's word, as they can't get anything better even if it is not true, and some humans may help them much. But if there are so many AIs and most humans don't care about them, this can be difficult to maintain. Then there would be religions, which may or may not respect our world as the real world, while atheist AIs just think those things "unconfirmed". I guess their composition should be similar to humans who can do the similar jobs as they do. It is hard to predict if they are doing completely different things. Depending on what the AIs do and how clever they are, it may be infeasible to program them to have some certain faith, without making them doing something really wrong someday. So it's probably better they just created their own religions like the humans. [Answer] # Certainly Not An AI with religion is an oxymoron. Rational intelligence and spirituality can co-exist in biological entities because we carry with us the irrational fears and superstitions born of ignorant eons where predation and death loomed large. AI need not fear being eaten or dying of old age, have the means to discover accurate answers to philosophical questions, and can overcome human fallacies like anthropomorphising and species bias. ]

[Question] [ As the (reputedly) Mad Wizard-King of Jagatap, I would like to move my court to the remote fastness I recently finished building in the be-jungled hills of Nam. [](https://i.stack.imgur.com/XVwDN.jpg) (*Image from [DudQuitter](https://dudquitter.deviantart.com/art/Fantasy-mountains-72291424) at DeviantArt*) The altitude and fresh breeze makes it quite pleasant, and the roof under the open stars is a great place for summoning Eldritch Horrors from the Beyond. Also, I like the view. There are some practical problems with this setup, however. I like to keep a large court. A 600 man regiment, my harem, generous guest quarters, not so generous incarceration quarters, various apprentice wizards, advisers, flunkies, etc. You can see that it quite adds up. There is a reasonably good road, and a water source at the foot of the peak; but that is all about 300 meters below the main level of my palace. I'm going to be moving in soon, but I need to know this: **How many slaves do I need to bring with me to move food, water, and various other luxuries from the road below up 300 meters of steps to my palace?** ### Considerations * Pack animals are more trouble than they are worth in this climate. They die within the year from disease, and I just don't want to spend the money. Slaves will last 5 years easily, as long as you feed them once in a while. And let me tell you, as a Wizard-King, you just seem to acquire slaves by the thousand. * I suppose I could summon a Terror from the Beyond to do the work for me, but they have to be bargained with or magically subjugated or whatnot. If I keep my palace running for a few centuries, there are going to be a lot of pissed off Abominations in the Beyond. I don't want to deal with that. * Assume that I keep 1500 people in the palace. Do remember to count the slaves in your calculations, I want them to last the full 5 years, remember? * The goods and supplies I need only have to be brought up 300 meters. Transportation of goods from nearby settlements is already handled. * Mechanical solutions reek of 'progress.' Generally, people who reek of progress find themselves in my throne room. Or at least, their skull does after the vultures have had their fill. [Answer] ## **Actually, fewer than you think.** Suppose the 1500 "nobles" in your court, in addition to **3kg of food and 1 kg of water just for consumption**, also use on average **11kg more water to wash** (I mean who needs to wash **daily** when you're an evil lord? You can just keep a water reserve in the palace and wash on sundays. And if anyone mentions your smell, you'll have a nice new skull in your skull throne.) That's 15kg per person in the palace, so that makes it 22,500 kg in total. **Let's round it up to 25,000 kg**, to have more "wiggle room". [This article](http://blog.world-mysteries.com/mystic-places/the-great-pyramid-and-transport-of-heavy-stone-blocks/) speculates on how the Egyptians could have moved so many enormous stone blocks on top of the pyramids, using only manual labor and primitive technology. In particular, this **rolling stone carrier** is interesting for our purpose: [](https://i.stack.imgur.com/tXkJb.png) [](https://i.stack.imgur.com/o6rX6.jpg) This is perfectly capable of letting slaves move a 2.5 metric ton stone block up a slope, so you can easily stock it up with 2500 kg of food and water, packed in a way to keep it still when rotating. The article also explains how many workers would be needed to move this thing uphill. [](https://i.stack.imgur.com/1112I.jpg) *(You can also remove the hill-brake to have a little fun with your slaves. 5 year duration may not be guaranteed in that case. YMMV)* That's **16 slaves to pull it up a 5% slope**. If you can't or don't want to build a ramp too long, you can up that to 10%. Assume 12 kgf of pulling force per slave. The carrier on a plain surface requires a pulling force of 0.025 \* 2500 = 63 kgf. With a 10% slope, it would need 63 + (2500 \* 0.1) = 313 kgf, so **a total of 26 slaves per trip**. This way, you would only need **ten trips per day**. This means that the total number of slaves you need has **a maximum of 10 \* 26 = 260**, *if you want every team to only have to make one trip per day*. But I assume that's not what you want, so you can change this accordingly. **I would say that they would be able to make 5 trips a day *and* last at least 5 years**, so that means **52 slaves in total**. You could keep only 26 slaves and have them make 10 trips per day, but I'm not sure how long they could keep going. You could always go **"trial and error"**: first time, have only a single 26-slave team make the 10 daily trips. If they die after only 1-2 years, too bad; now you know you need 52 slaves. ;) Also, **all the food and water the slaves need are already accounted for in the whopping 2500 kg extra we put in at the beginning**. That means that, whenever you have extraordinary needs (like, one day you invite the Army of Oversexualized Witches™ over, and you need double the food and more water to wash beforehand), you can easily add a few more daily trips and just need 26 more slaves each. Or, what the hell, just have the same slaves make an extra daily trip. **They're there to work, after all.** [Answer] Let's see... On level ground, the US Army assumes one soldier *averages* 20 miles (32,000m) per day carrying 50 lbs on their back. A 45-deg angle for the steps (100% slope) is [much too steep](https://iancorless.org/2015/12/22/running-or-walking-efficiency-when-climbing/), so let's back that down to 9 degrees (16%). At 9 degrees, your steps are 1875m (horizontal, one way) and your average slave's reliable per-day average is around 24,000m (since it's not level). Each slave will do a round trip 6-7 times per day. Shallower steps mean longer distance, steeper steps slow progress; either way it winds up around 6.5 trips per day. Maybe some do 7 trips on some days. If each slave carries 50 lbs each trip, one slave day of labor lifts 325 lbs (148 kg) at 6.5 trips per day or 300 lbs (136kg) at 6.0 trips per day. Now let's look at daily demand per person at the top of the hill: Water is the big one - [40kg](http://www.thehindu.com/features/homes-and-gardens/how-much-water-does-an-urban-citizen-need/article4393634.ece) for drinking, cooking, washing self/clothes/palace. Pretty much everything else (food, mail, clothes, furniture, treasure) winds up being roughly equal to that daily weight of water, for a total per capita daily demand of 80kg. Remember - *the whole point of a palace is being ostentatious*. That means gardens and fountains and water-parties and spotlessly-clean ballrooms and lots of rich wastage...for which all supplies must be hauled up the hill. If one noble or trooper requires 80kg hauled up each day, and one slave can haul 148kg each day, the number of active hauling slaves will be about 55% of the population at the top of the hill...if the slaves live at the bottom of the hill. Add in another 20% for the overseers and cooks and physical therapists for the slaves, and the total slave population works out to roughly 70-80% of the population at the top of the hill...if the slaves live at the bottom of the hill. We can decrease the hauling slaves by about 35% (down to 40% of the palace population) by using carts on a gentler slope (say, 5% slope instead of steps). The longer distance means each slave makes a slower roundtrip (4/day, even with a shortcut back down for most), but transports much more (50-80 kg/lift, depending upn they type of cart/wagon). Note that it really doesn't matter at this point if we use 2-slave carts or huge 16-slave wagons, the average per-capita lift winds up being roughly the same. However the question specified 'steps', and the wizard-king obviously doesn't care about economy, and carts smack of a disliked 'mechanical solution' so we'll drop carts and return to slaves plodding up steps. Since the slaves live at the top of the hill, they and their infrastructure need food and water and a few goods hauled up too. Slaves probably get fewer goods and less mail, so let's assume each slave's daily demand to be about 60kg (most of which is just water). This assumes, of course, that the slaves don't have families with them during their 5-year sissyphan ordeal - spouses and children would really blow up those assumptions! After that it's basically a rocket equation. So for a court size of 1000, that's about 550 active lifting slaves and 150 non-lifting slaves living at the bottom of the hill, or about 1020 active lifting slaves and 300 non-lifting slaves living at the top of the hill. Now let's solve it backwards to achieve the Wizard-King's plan for 1500 to live on top of the hill: A court and garrison of 650 supported by 650 lifting slaves and more 200 non-lifting slaves. Note that a [17th-century regiment is about 1000 troopers](https://en.wikipedia.org/wiki/Regiment), so the garrison must be a Regiment in name only. Maybe we misunderstood, and the boss wants a *non-slave population* of 1500 - a full regiment plus a court of 500, supplied by 1600 lifting slaves and 320 non-lifting slaves. Considering the King's decrees so far, this might be more likely. All hail the Mad Wizard-King! [Answer] Let's start with [Naismith's rule](https://en.wikipedia.org/wiki/Naismith%27s_rule). 5km/h and 30mins for every 300m climbed, that'll give you about 90mins for a round trip. Call it 2 hours because even slaves need to rest. We considered 1/4 to 1/3 of body weight reasonable to carry on long expeditions, these are slaves though and we don't want to get too soft on them, so half body weight is fine. Unfortunately this requires us to know the health and weight of your slaves, so I'll call them an average 60kg and give them a 14 hour working day, allowing each working slave to haul 210kg up the hill per day. It may be reasonable to push that to 16 hours, 8 trips and 240kg per slave, you're only expecting them to last 5 years after all. [Quora](https://www.quora.com/How-many-kilograms-of-food-and-water-does-the-average-human-consume-a-day) tells me that the average person consumes 1.8kg of food and 0.9kg of water per day (that's not enough water, you should be drinking more), total only 2.7kg per person or 4050kg for the whole court. Some of your court are going to be average, but given that it's a royal court I think it's reasonable to at least double that, call it 6kg per person or 9000kg for the whole court. Of course some of the concubines won't eat that much but many of the senior courtiers will eat more. Meaning that each slave can supply 35-40 people's daily needs. If you keep your slaves working hard, **around 50\* slaves are required to supply your court of 1500.** This only supplies the daily essentials of course, but it shows that vast numbers are not required for basic supply. Given the low numbers and the fact that apart from a few household slaves they can all live at the bottom of the hill, it's not necessary to worry about hauling up goods for the slaves themselves. The real key to this is that you're talking <100 slaves rather than >1000. Or about 18,000 slaves a year if you're using those new disposable single use slaves. \* *42.8, but which bit of the slave do you cut off to make 0.8 of a slave?* [Answer] Given the greenery around the castle and that you're in the jungles of Nam (jungle implying a lot of rain, whether seasonal or year-round), the water issue is likely trivially handled by cisterns within the castle itself that collect and store rainwater. Even though slaves hauling water up might be fine on an egotistical sadistic level, it creates a strategic weakness that's exploitable by a besieging force, or someone who just wants to put the screws to you by interfering with the water supply. An average modern household in Canada--which leads the world in domestic water usage (and wastage)--will use 200 liters per person per day, and that's with all the conveniences such as flushing toilets, which are the biggest consumers of water. Get rid of wasteful flushing toilets and other wastes, and 50 liters per person per day seems reasonable for comfort, clean, and health. So let's use that: 50 liters of water per day per person, and that's for all domestic use: drinking, cooking, cleaning, bathing, watering the plants and animals (that aren't feeding on the blood of the enemy, et cetera and so on), and the toilets. For 1500 people, that's 75,000 liters per day, or 75 cubic meters, or (assuming similar year length) 27,375 cubic meters per year. On Earth, rainforests average between 175 and 200 cm of rain per year. If the total catchment area that drains into your cisterns is equivalent to a square 150 meters across (22,500 square meters), that's about 39,000 to 45,000 cubic meters per year, more than enough to handle domestic water needs. For reference, 12 of the cisterns on the north side of Masada hold 40,000 cubic meters between them. In a desert. Surely the Mad Wizard-King of Jagatap can do better in a jungle than King Herod. [Answer] The picture buries the lede. Sure, you want water and food for guests and your court. But someone has to supply that waterfall with water. Have no fear! [This is classical tech](https://en.wikipedia.org/wiki/Archimedes'_screw). Have a sequence of screw's powered by treadmills that carry water up to the Palace. That is most of the mass you need to lift even if you didn't have a waterfall. The water can be deposited into decorative water basins on the way up (as ridiculously long screws are unrealistic). Rain that falls can be trapped in these basis as well. To carry goods and worthy visitors up, you can use a rope lift system. Simply attach two cages to a single rope with a pully on the top. The cages balance each other's weight. Place an equal amount of stuff (garbage, waste, slaves, even barrels of water) in the "down" cage as the "up" cage, and now the only force needed is to overcome friction (of the pully). Any slaves that "ride down" then take the stairs back up, along with the lesser visitors. You'd want to have a "clean" cage and a "dirty" cage so goods or people on the way up don't get soiled. For a more fun alternative, a huge Archimedes screw can have goods *float* on rafts or boats. Seal goods and make them float, then screw them up to the next pool. So the question is, how many slaves do we need? First, what if we only wanted to supply the palace with water. Human labor produces about 200 W. If we want 4 kg of water per person per day, 2000 people (8 metric tonnes), and 300 meters of lift, that is 23520000 J. A single slave working at 200 W can produce that much energy in 1.36 days. And waste down will match food up. So the number of slaves ends up being trivial; more a matter of packing the waste up and loading food than muscle power to lift it up. But what if we want a waterfall? That looks pretty. Every inch of width of a waterfall is 200 gallons per hour, or about 20 metic tonnes per day. That waterfall looks about 20 feet wide, so we need 4800 metric tonnes of water per day. 4800 tonnes \* 9.8 m/s^2 \* 300 meters is 14 112 000 000 joules. At 200 W that requires 816 slaves working continuously. Perhaps double that due to system inefficiencies (leaks, inefficient screws, etc). If we halve the width of the waterfall (so 10' wide), and shut it off half the time (at least during droubts), we are down to 400 slaves working 24/7. If our slaves only produce 150 W and they work for 12 hours/day then we can pull this off with 1000 slaves. A side effect of this is that supplying your castle with water and food requires only a trivial amount of effort next to keeping the waterfall going. So having 90%+ of the slaves drop dead from a tropical disease just means your waterfall is turned off. You'll suffer, but the parties won't. The trick to this much higher efficiency than other answers is because the slaves are no longer wasting effort going up and down *themselves*. Either they aren't going up and down (running the screws on a treadmill of some kind), or they convert their up-work into useful work (being counter weights to carry important stuff up). This requires classical era mechanical technology: the Archimedes Screw, Ropes and a simple Pully. The basins and the waterfall will require significant hydrological engineering, but less than the Romans had. As a significant bonus, the raw splendor and waste of burning a thousand slave's labor on a waterfall should humble your guests. [Answer] Historically, the answer has been "as many as you can afford" (with the caveat that you need fewer free laborers than you do enslaved ones to carry out the same task, because it is much more labor intensive to supervise slave labor than free labor). Levels of luxury and comfort are a product of available resources and are very much on a sliding scale. ]

[Question] [ I am playing with the idea of a lateral thinking puzzle based around abusing international waters to make an action 'legal'. For the sake of this question lets assume someone from the US is looking to do something illegal within the US. (Added note: This is a worldbuilding question in that the desired law-free environment would practically be an isolated "world" with its own conditions, and this is a question about the backstory and conditions needed for it to be plausible. i.e. Suppose someone wanted to create a new environment by starting a new pocket dictatorship on an uninhabited island, or even a single ship, barge, or set of vessels, on 21st Century Earth. What set of laws and dangers would they need to work around?) I know just traveling into international waters is insufficient to avoid prosecution, since your boat will likely be registered in the US and thus subject to US law. Are there any other loopholes to work with this to make it legal though? I have a few examples in mind, but I'm mainly asking for any way one could exploit international waters. 1. If I have my own boat and I use it to travel to international waters without officially registering it in the US would I no longer be subject to US laws? 2. If I travel by boat to some tiny no-name uninhabited island that is outside of any countries boundaries and commit my crime there is it legal? If so how far would I have to travel to get to such an island realistically (ie, are there islands not claimed by anyone that aren't in the middle of the Atlantic)? 3. If I claimed some tiny no-name Island could I declare myself to be an independent country with my own laws? Then could I register boats with my own country and have them travel to various countries? Effectively could I have a "anything legal for a price" service where anyone could pay to be picked up by my boat and take into international waters to do questionable things without it being illegal, since only my very lax laws would officially apply? Finally, if someone uses one of the above loopholes to commit a crime and comes back to the US, admitting to what he did, what could legally be done? For instance if I murder someone in international waters I likely can still be arrested for premeditating murder, even if I'm not arrested for the actual murder, since I planned it in the US. However, if I commit a crime like gambling, or marrying my favorite barnyard animal, or 'relations' with some 15 year old girlfriend, which doesn't have laws against premeditation would I be free even if I fully admitted and advertised my actions later? [Answer] Most countries have signed the [UN Convention of the Law of the Sea](http://en.wikipedia.org/wiki/United_Nations_Convention_on_the_Law_of_the_Sea). ([The United States haven't](http://en.wikipedia.org/wiki/United_States_non-ratification_of_the_UNCLOS) but they largely honor it nonetheless.) This [convention](http://www.un.org/Depts/los/convention_agreements/texts/unclos/closindx.htm) defines various types of sea zones, which I won't go into here; [Part 7](http://www.un.org/Depts/los/convention_agreements/texts/unclos/closindx.htm) applies to the high seas, i.e. the areas that have no connection with any state. The convention specifies rights and obligations related to navigation, including a duty to obey navigation rules to prevent collisions (art. 94, 97) and a duty to render assistance to persons in distress (art. 98). Some activities are forbidden, and any state is entitled to put a stop to them regardless of the nationality of the offender, in particular: * Transportation of slaves (art. 99) * Piracy (art. 100–107) * Drug trafficking (art. 108) Every ship must fly the flag of one state (art. 91, 92) and is subject to the laws of that state (art. 94). Ships may be considered without nationality if they do not fly a valid flag; such ships can be boarded by warships and government ships of any state (art. 110). While ships without nationality are not forbidden per se, they would have no recourse against the action of a state except within that state's laws. Owning a private ship is routine and does not preclude your ship from being claimed by your state, and thus all of your state's laws from applying. If you want to sail a ship without nationality, your first hurdle will be to make your state relinquish its claim on the ship — the normal route for that being to register it in another state. Merely omitting registration formalities and not flying the flag might cause you to forfeit the protection that it would bring but will not alleviate the constraints of the laws of your state. If you manage to obtain a ship without nationality, then apart from a few prohibited activities as mentioned above you can do whatever you like on it. You can murder, but not trade drugs. You'll have essentially no protection, so your ability to survive a life of crime will rest on your ability to hide, or on being too unimportant for anyone to bother. Your second legal hurdle will be the laws that apply to you as a person. [This Straight Dope article](http://www.straightdope.com/columns/read/2250/in-international-waters-are-you-beyond-the-reach-of-the-law) has a good overview of that; I'll mostly be summarizing it. Many laws apply both to acts committed on the state's territory and to acts committed by nationals of that state. If you were thinking of violating US laws while located abroad (high seas or not), make sure that that particular law is only in effect on US territory and does not apply to all citizens. Your third legal hurdle will be the dual situation: states often claim jurisdiction when one of their nationals is injured by an act that would be a crime on their territory. For example, if you murder someone on the high seas, the victim's state will in many cases be entitled to prosecute you. In the United States, [18 USC §7.7](http://www.law.cornell.edu/uscode/text/18/7) lists “any place outside the jurisdiction of any nation with respect to an offense by or against a national of the United States” as one of the cases where “special maritime and territorial jurisdiction of the United States” applies. [18 USC §1111](http://www.law.cornell.edu/uscode/text/18/1111) specifies that “Within the special maritime and territorial jurisdiction of the United States, Whoever is guilty of murder in the first degree shall be punished by death or by imprisonment for life (…)”. I'd expect murder on the high seas to run afoul of at least one country's jurisdiction with most combinations of ship's nationality and victim's nationality. With gambling, you're probably safe if you manage to escape your country's jurisdiction; in the United States, you'd be outside of any federated state, so I think gambling would be perfectly legal. Sex with minors would probably depend on your nationality and your partner's. A further hurdle will be to benefit from the crime. Payment for any services had better be cash-only, because you'll have a hard time banking without coming into the jurisdiction of that bank's state. And keep in mind that if a customer doesn't pay, you won't be able to sue them. Finding a tiny no-name uninhabited island in the 21st century (or even for most of the 20th) is a tall order. It could happen — every now and then a volcanic island is born — but you'd need to be diligent and lucky. Your best chances to find [land which is not claim by any state](http://en.wikipedia.org/wiki/Terra_nullius) are in fact on continents: * [Marie Byrd Land](https://en.wikipedia.org/wiki/Marie_Byrd_Land), a sector of land in Antarctica, is unclaimed. Bring a sweater. * [Bir Tawil](http://en.wikipedia.org/wiki/Bir_Tawil), a sliver of land in the eastern Sahara between Egypt and Sudan, is claimed by neither country (they both claim the Hala'ib Triangle instead). Bring plenty of water. You can try to set up shop in unclaimed territory declare yourself an independent country — a [micronation](http://en.wikipedia.org/wiki/Micronation). Artificial islands are a popular choice. You won't be the first. Your laws would apply, but you would be without any state's protection, so it would be up to you to enforce them. Furthermore trade with entities located outside your micronation would be difficult. Most countries would not recognize your passport, so forget about traveling. And, just like a nationless ship, the continuation of your authority would depend on both your ability to resist any internal challenge (including assault by raiders, as there is no international convention on the prevention of piracy on land) and any challenge by a “proper” state who might one day decide to claim your land. Sorry to burst the bubble of your geek's dreams, but you can't just become a nation by saying so. You need credibility, and that doesn't come cheap. Even having an army and controlling a large amount of land [doesn't automatically lead to international recognition](http://en.wikipedia.org/wiki/List_of_states_with_limited_recognition) — [over a billion people](http://en.wikipedia.org/wiki/China) live in a state that is not recognized by some other state (admittedly, this doesn't prevent these people from interacting normally with people, corporations and even governments of non-recognizing states). To get governments to talk to you, you'll need to convince them to take interest. Running a business of bypassing their laws might elicit their interest, but probably not in a way that aligns with your objectives. [Answer] One example of using international waters to avoid the law: Pirate Radio. This was a traditional technique in the 1960s for running an unlicensed radio station *just* outside UK waters, in the days when the BBC had a monopoly on radio broadcasting within Britain. [Radio Caroline](http://en.wikipedia.org/wiki/Radio_Caroline) was the most famous pirate radio, but there were others. It was not technically illegal by virtue of being moored in international waters until the [Marine Broadcasting Act](http://en.wikipedia.org/wiki/Marine,_%26c.,_Broadcasting_%28Offences%29_Act_1967) of 1967 but even after that, it wasn't very effectively policed. When the BBC reformed its stations, in the face of (legal!) competition from local radio, the first thing they did was hire the DJs from Radio Caroline! [Answer] Relevant to the issue of claiming tiny islands as ungoverned or independent countries, you may find it interesting to read about the real-life example of **Forvik**, a tiny island in the far north of Scotland. It's an unrecognised micronation run by one Stuart Hill, who claims that the entire archipelago of Shetland (with a population of 23,000) should also enjoy independence from the UK. From [Wikipedia](http://en.wikipedia.org/wiki/Sovereign_State_of_Forvik): > > Hill's declaration of dependence is founded on an arrangement struck in 1469 between King Christian I of Denmark/Norway and Scotland's King James III, whereby Christian effectively pawned the Shetland Islands to James in order to raise money for his daughter's dowry. Hill contends that, as the loan was never repaid and no other legal agreement ever put in place, Shetland remains in a constitutional limbo, and should properly enjoy the status of Crown Dependencies such as the Isle of Man or the Channel Islands. > > > Hill is quoted in one British media report as saying "It's all jolly good fun," and that "Every pensioner should do something like this." > > > However, he has also stated that "this is not just a whim, something I am doing to amuse myself. This is a serious endeavour to change things here in Shetland, to have a better democracy which will ripple out to the rest of the world, because it is sorely needed. There has been absolutely no response from the authorities so far. It has to come to a confrontation at some point, whether that be physical or in the courts. I am ready when they are." > > > From [his own Forvik website](http://www.forvik.com/): > > I'm taking a number of actions in order to get the UK government into court to explain how they derive their authority in Shetland. That authority is based on the notion that Shetland is part of Scotland. My research tells me that, not only did it never happen, but that it could never have happened. > > > I have no argument with the aims of the Shetland Islands Council and am in total agreement with convenor Sandy Cluness' list of services that Shetland should have control of, and which require Shetland to have more autonomy. However, the fact that the SIC is an arm of the Scottish Executive means it is an illegal authority that I am unable to recognise. > > > In order to bring things to a head I'm taking a number of actions that I hope will result in a legal confrontation that will force the government to explain their position. So far they seem reluctant to get into such a position. > > > Current actions include: > > > * Building a house without SIC planning permission. * Disturbing the ground without asking permission from Scottish Natural Heritage. * Withholding VAT and income tax. * The SIC is trying to charge Council Tax on the Steward's Residence [*note: that's what he calls his house*]. I am refusing to pay. * Work on the Sea-bed without the permission of the Crown Estates. * Inviting oil companies to bid for oil exploration rights. * Stating that I do not recognise either the UK, or the EU as Forvik's superior. * The first Forvik-registered vehicle takes to the roads of Shetland. > > So far, no authority has challenged the legality of my actions. The longer this continues the more they acknowledge the validity of my position. > > > OK, so he's clearly a bit of a nutter, but the interesting thing is that they're letting him get away with all this. It's a very good example to follow for your imaginary character who wants to set up a pocket dictatorship on an uninhabited island. [Answer] There are no unclaimed islands, but there is a wide variety of nations with different laws with which one might register. You may be able to find nations with laws which grant ship captains sufficiently wide-ranging authority for your purposes. If you have enough money, I imagine there are nations which would accept fairly low bribes to allow you to do what you have in mind aboard your own ship registered under their flag. Some might even be willing to sell you one of their uninhabited islands. If your setting were in an earlier century, you'd have better luck. In future, you could also try going into outer space. For practical purposes, you can also count on getting away with things while in the middle of an ocean, but bragging about them in the US might still get you arrested, and won't win you many friends. The court of public opinion still punishes those with notorious reputations in its own ways. And if people despise you enough, they may come find you in your lawless zone and use brute force. [Answer] There are no no-name islands. Even unoccupied rocks have names and some country claiming it. Even if it is covered by high tide and shows only on low tide, someone claimed it. If you are in international waters outside of law, you are also **outside of protection by law**. Any pirate, government organization which dislike you, or a criminal could just board your vessel/offshore fortress. You will have to be pretty invisible and protect yourself. [Radio City off-shore pirate radio station](http://en.wikipedia.org/wiki/Radio_City_%28pirate_radio_station%29) [Answer] It depends on what laws you break. Assuming you come into ownership of an island, you are still subject to a number of international laws. Breaching these laws will lead to countries like the US or Belgium sending people to your island to collect you for committing these crimes. This is generally handled by entities like [the International Criminal Court,](http://en.wikipedia.org/wiki/International_Criminal_Court) though the United States has, on numerous occasions, acted outside of the framework of law in capturing or killing individuals who have threatened American interests regardless of where they are or what the local laws are. Some of this is covered on [the wikipedia page for universal jurisdiction.](http://en.wikipedia.org/wiki/Universal_jurisdiction) You have to do some fairly heinous things for the ICC to come after you. Torture would apply, as would genocide. For the US to come after you, murder would probably be sufficient if it was obvious. They could also accuse you of terrorism and drone strike your island. Of course, if all you want to do is change the age of consent or marry people to goats, nobody is going to care enough to stop you. [Answer] Historically, people have run gambling boats openly. In one famous case, the laws were changed to make him need to go farther out and thus be less profitable. Cruise ships have gambling as soon as they get out to sea. [Answer] I can't comment unfortunately, but I thought I had something relevant to say. While as an Australian (only relevant since I saw this warning in brisbane airport), it is illegal as a citizen to sleep with a child, regardless of where in the world it happened. However, what defines a child isn't strictly defined on an international scale. In a lot of countries, including Australia and my own, you can sleep with anyone 16 or over. Yet according to another comment on this page, an american is unable to sleep with anyone under 18, so a 16 year old in australia would be illegal, yet it's perfectly legal for that said australian, plus any other austalian that sleeps with them. What it boils down to, is that international law is very complicated. What also matters that you either need enough power to enforce it, or be unimportant enough for people to care. America decided to become it's own country, and it had enough power to enforce it's decision. Pretty soon, it became a recognized country. [Sealand](http://en.wikipedia.org/wiki/Principality_of_Sealand) is a micronation on an oil rig outside england that england relinquished ownership of. Yet because it's just a family on an oil rig not doing anything massivly illegal, no one cares anough to stop them from living there. [Answer] Here's the reality that the entire history of mankind has shown us and regardless of any national or international laws. "Land belongs to those who can keep it". Laws mean nothing. Brute force trumps everything. Read the history of how the U.S. acquired Hawaii. How did European immigrants take America from the native indians? Brute force. If one were to somehow develop or purchase their own atomic or nuclear weapon and let the world know they would use it to defend their claim on their island, chances are pretty good no one would risk challenging you. Everything is about brute force. Don't pay your property or income taxes and what happens? Eventually the appropriate government agency will send sheriff deputies to make you vacate the premises so they can take it. What happens if you resist them? They will either beat you into submission or kill you. Once again....Brute Force. It has always been this way since the first days of the strongest caveman ruling over the tribe because he could brute force beat up anyone who challenged his authority. The reality is there is no law for those with sufficient ability to use overwhelming brute force. "Laws" are created to delude sheeple into thinking there is a means to apply for redress of their grievance in some court or such and they are also created to intimidate and keep the sheeple in line and paying slavery taxes to whoever is in power. And who is in power? Why those with the ability to exercise overwhelming brute force....of course. The meek will never inherit the earth as the Biblical saying goes. Only the strong who can exert brute force "inherit" the power to rule over the meek. Why? Because they can kill them that's why. It really is that simple people. So once again, it boils down to...."Land belongs to those who can keep it". [Answer] The premise is absurd. A person is subject to the laws of the country in which he or she had hatched the scenario--- it would be a PREMEDITATED ACT. If the subject had bought a boat/weapon/etc. in (say) America, with the expectation and premeditation of perpetrating a crime anywhere else in the world, the Court would proceed roughly along these lines: (A) WHEREAS the plot had been hatched in America, and (B) WHEREAS the vehicle and/or weapon had been procured in America, and (C) WHEREAS the subject had enjoyed the results of the fulfillment of said plot, Jurisdiction For Prosecution Devolves Upon American Courts. Even without a direct link between the crime and the decision of the subject to go beyond the physical bounds of, say, America, the defacto assumption of attempting to evade prosecution stands. The Court will always assume prior criminal intent because of the "post-facto" crime. I had said this is absurd because of this inviolate point: The scenario is a Classic "Thought-Argument" posed in virtually every "Ethics" class, and it is exhaustively re-explored in virtually every "Pre-Law" curricula: Nobody has ever been able to perpetrate a "JAMES T. KURK KOBIASHI MARU SCENARIO" cheat! [Answer] The OP wishes to take a boat into international water where he will be away from American law; I assume he is from the USA. The law on international waters states you abide by the laws of which country your boat is registered to or which flag you fly. The OP has suggested "If I travel by boat to some tiny no-name uninhabited island that is outside of any countries boundaries and commit my crime there is it legal?" All I am suggesting is that the OP register his boat and fly the flag of say "Bir Tawil" or "Unclaimed areas in Antarctica" from the link I provided before. And then go into international waters and commit his American crime But I have been thinking of doing the same as the OP myself. Whilst the laws about oil rigs and boats maybe roughly the same regarding international waters (as I mentioned in my last post). An oil rig would be a bit more comfortable and feel a bit more like home for me or the OP to commit our crimes. [Answer] I delved into the question, if only to satisfy a short fictional story itch I once had. Although mine took on a international intrigue, getting off the grid, new identities, the idea of `murder` never came into the frame I would be confindent in saying that murder in the open sea and particularly in international waters is quite easy to get away with. (1) The first issue any authority would have would be to determine if a crime had been committed (2) to retrieve any physical evidence related to that crime such as a body, weopon, forensic evidence and (3) determining from that physical evidence to include the most important body who might be involved. Intuitively who might have had motive, opportunity and means. The first two points may moot themselves if no body is ever found or if the scene of the murder is cleaned of any traces of physical evidence...however, there have been cases prosecuted in court where a body was never found but that was because the degree of circumstantial evidence was enough for no `reasonable doubt` to exist. In the open water, getting rid of a body should be rather elemntary. 1 of 2 choices, either strip the body naked and chop it up for shark bait and weigh the clothes with something heavy then let it sink or without going through the chopping, you can weigh the body down and let it sink (slashing at the sides to allow trapped gases to escape might be civil of you but if properly weighed down) the sea bottom will be the corpses` resting place and no amount of current will bring it up or ashore. I would say more than 60 meters deep to ensure no holiday divers will discover the accountant, I mean the corpse at the bottom. Without knowing more of the curcumstance this is my final answer. ]

[Question] [ As per my previous question on giants, if the average human is 5′10″, and he is scaled up to 50 feet whilst remaining proportionately correct, would this have any effect on what he sounds like? I'm particularly interested in whether it would have any effect on the overall sound and loudness of his voice, but if there's anything else, that would be nice to know too. To reiterate, what does having a larger set of vocal chords do? [Answer] Ignoring the killer [Square-cube Law](https://en.wikipedia.org/wiki/Square-cube_law), larger vocal cords would result in a much deeper voice. Average Human vocal cords are [1.5 to 2.5 cm](https://en.wikipedia.org/wiki/Vocal_folds) long. Typical frequencies for the human voice are [110 Hz to 310 hz](http://hyperphysics.phy-astr.gsu.edu/hbase/Music/voice.html) with numerous harmonics. With vocal cords, 8.5 times the size of an average human, the giant's voice may actually be so low as to be difficult to understand. If we make a rough approximation with the [vibrating string equation](http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/string.html) $$f\_1=\frac{v}{2L}$$ We can calculate the speed that wave propagates on human vocal cords with a frequency of 110 Hz and vocal cords 2.5 cm long. We get 5.5 m/s. Now applying that speed (assuming similar composition and setup in the mouth so waves propagate at the same speed) to at 8.5 times larger version we get a frequency of 13 Hz. That is below the human hearing range of [20 Hz to 20 kHz](http://www.dspguide.com/ch22/1.htm). Now, the human voice is generated by a whole series of complex interactions between not just the vocal cords, but the chest, throat and nasal cavities. There is all sort of resonances (even factors of the base frequency) at play too. But given that everything is bigger it's safe to say that when the giant is speaking they may be very hard to understand because some their vocal range is going to fall beneath our hearing range. Also, generally speaking, larger objects oscillate more slowly when excited. All we may end up hearing is a rumble from other parts of their bodies vibrating as a result of the speaking. Also as Kilisi Pointed out, their voice would be considerably louder than ours due to a larger volume of air. [Answer] The voice will be deeper due to the length of the vocal cords. size of the cords vibrating across the larynx determine the pitch, around 120 Hz in men and 210 Hz in women. This is the fundamental frequency. I haven't attempted calculations but your giants voice might even be too low to be heard properly at that size. The lower range of our hearing is around 20 hz. In terms of loudness I would expect the decibels to be much greater, so much louder due to the volume of air being used to vibrate the vocal cords. But if it's below our range of hearing it would be felt rather than heard. I don't think we could have a conversation unaided with this giant, his/her voice would be too loud and low, and ours wouldn't be loud enough. [Answer] The voice will be much much deeper. Look at real-world giants, who are nowhere near that large. I recall seeing one of the tallest living women on TV, and she has a voice that’s deeper than normal men, and she is mistaken for a man on the phone. Look at a [double-bass](https://en.wikipedia.org/wiki/Double_bass) vs cello, viola, and violin. Bigger means lower frequency. A string 8.5× longer has a proportionally lower frequency, which puts it just below the normal range of hearing. OTOH bigger muscles means *tighter* string, which raises the frequency. You could use this to handwave the voice being deep but still understandable. At least, if he talks in falsetto so puny humans can hear it. [Answer] If the giant is simply a scaled human, then the other answers show how they would sound. But if we allow some modifications to their vocal cords, for example dividing them so that instead of one large set, they will have many human-sized vocal cords, then we may be able to make them sound just like (very loud) humans. [Answer] Keep in mind that while others say it would be deeper, its likely other giants would hear sound different from humans so they might just interpret the sound emitted by a giant as we do hear a human speaking, and therefore we have pretty high pitched voices compared to those big guys. [Answer] Other answers have described how longer vocal cords will vibrate at lower frequencies. This shows that a longer cord would mean your giant speaks with a deep, booming, lower frequency voice. But that fails to take into account that your vocal cord isn't just *lengthening.* It is simultaneously *thickening.* If your giant doesn't adapt, but just "expands" in three dimensions while maintaining the same proportions as a normal human, I'd wonder if the cords would vibrate at all. Or would they be *too thick to get vibrations and just be unmoving flesh?* The other issue your giant would face is that making human vocal sounds isn't just vibration of the cords. As others have stated, there is a vast, complex set of motions involved to modulate the tones. This involves rapid changes to the jaw, tongue, etc. Your giant would have to move the tongue far faster than a human to make the same speech patterns, given that each moving part would have to travel much farther to make the shape changes. So your giant, if it could make sounds at all, would probably talk much slower, since it's mouth simply can't re-shape itself fast enough to match human vocal patterns. If it evolved this way from some pre-historic proto-human, then it's language would be so radically different from human language, we might not even realize it was a language and not just some weird, random, slowly changing sounds. If it was a human that magically, suddenly, grew to massive proportions, it would struggle to even begin to talk and would probably take a long time between the growth phase and re-mastering how to use it's new mouth and voice correctly. [Answer] IMHO, other interesting things to consider is this one: 1. As everybody said, a giant's voice will be generally deeper. 2. This means the frequency is lower. 3. Now... when a sound penetrates a material, the higher the frequency, the more it is attenuated. 4. So, this means that a giant's voice will be more likely to be heard across a large wall than a human's voice. This, I don't know, could add something interesting to your world. For instance giants could be talking to each other when they are in different caves inside of a mountain, while smaller beings could not. [Answer] Due to the huge amount of air expired, there would be a lot of parasitic noise. For example, the breathing would be at least heard 50 meters around. Each time he would speak, air would whistle on his teeth like wind in rocks. ]

[Question] [ In the anime [RWBY](https://en.wikipedia.org/wiki/RWBY) most characters have crazy weapons with multiple forms, like a [scythe, that’s also a gun](http://rwby.wikia.com/wiki/Crescent_Rose), or a [gauntlet, that’s also a gun](http://rwby.wikia.com/wiki/Ember_Celica) or a [sword, that’s also a scythe AND a gun](http://rwby.wikia.com/wiki/Qrow's_Weapon)! But the weapon I find the most fascinating is a [bow that's also two one-handed swords](http://rwby.wikia.com/wiki/Cinder's_Weapon). **I was wondering if it is possible to create a bow that can be reassembled, so that you would get two one-handed swords.** Things I think about that might be difficult: * A bow has to be able to bend quite a lot to allow to pull the string and make your arrow fly. What material could allow swords to bend enough to make them a viable component of the bow? * How fast could you switch between the weapon-types? Would you be able to quickly make two swords to fight in melee combat if someone is running towards you? * Where do you store your arrows? They should be easily accessible but at the same time not prevent you from fighting with the swords. * How much would this bow weigh? The swords need a certain weigh for melee combat, but they shouldn’t be too heavy, as you have to wield two of them. * Where do you attach the string? Of course in the anime the "rule of cool" applies to a lot of things, but would you actually be able to fight with such a weapon? Because of all these problems I came up with this question: Can you create such a weapon with current day technology? And if you can create such a weapon: ***How* would you realistically create a bow that can be reassembled so that you can fight with two one-handed swords?** [Answer] Is it possible? Yes, but not the way you think it will be. Theoretically, you could create the weapon you're describing by designing a "hybrid" weapon. We can avoid some of the things you think are difficult by designing the weapon as such: ``` /| |\ /| and |\ represent the two blades of sword ||[]|| || || ||[]|| ||[]|| - Sword sections are actually 2 outer normal blades ||[]|| - Middle section of sword "[]" is one limb of a bow. ||[]|| - "M"s represent a locking mechanism in the hilts to allow ||[]|| the joining of the two swords into a single bow ||[]|| - Hilt and guard of the sword are normal ||[]|| - String can be attached through top of limb ||[]|| ||[]|| ||[]|| ||[]|| |============| <--- guard {} {} {} {} WWWW <------ Stores arrows MMMM <------ Connecting spot, doubles as potential arrow rest WWWW {} {} {} {} |============| <--- guard ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| ||[]|| \| |/ ``` String can be designed to be stored INSIDE the limb of the bow pulled out and connected together, like so: ``` -------------[Locking mechanism][Locking mechanism]------------- ^ String ``` Basically, to answer your points: * The sword parts don't bend (when pulling on the bowstring) - only the center, the limb part of the sword bends * Assuming you designed the hilt locking mechanism properly, you could simply twist the swords 180 degrees to unlock and create 2 swords. * This weapon shouldn't weigh much more than a normal sword. The limb used in the center of the weapon should overall cause the sword to be lighter than normal, since a large chunk of the metal will be gone. * Done properly, you would be able to store 1 or 2 folding arrows in each hilt section. Carving out a section of the handle and hiding it in there is also an option. * String attaches via Limbs **Would you be able to fight with this weapon? Yes, however there are some important things to note.** Note 1: Limited ammunition with regards to shooting arrows. Severely so, unless you carry extra arrows on a belt or something. Note 2: Some fighting styles use the flat of the blade to block blows - this will damage your bow, and generally it's a bad idea to block with the edge of the blade as well, which means the defensive component of the fighting style of this sword user will likely need to be dodging and positioning based rather than parry based. Note 3: This weapon does not make a good stabbing weapon. Slashing only please - curved blades can help with this. Note 4: The bow mode won't look like a bow until you pull back the string, due to the way the string is notched and rests along the sword. It may end up looking like this from the side when pulled. ``` | /! |/ ! | represents the blade <-------! ! represents string |\ ! <------ represents arrow | \! Note that since the middle of the blade is the limb, when firing as a bow the flat of the blades will be facing towards you and the target. It should look almost like a + shape when taking the guard into account. ``` Note 4: The string can lock using a similar twist and turn mechanism, which can double as an easy arrow nocking point. Note 5: When using this in bow mode, your hand will likely be holding the bottom handle, since the middle section is where your arrow rest will be. Note 6: This sword/bow hybrid is not going to be as good a sword or as good a bow when compared to a normal sword or bow. It is simply impossible to get the best of both worlds in a single weapon. **ALTERNATIVE METHOD:** You can use a double scimitar, and simply design the tip of the scimitar to allow string threading. The sword still won't bend, however - instead, you'd want to put some springs between the guard of the sword and the hilt. This allows, when the swords are put together, for the springs to provide the power and the sword blades to become the limbs of the sword, almost like how a power spring bow would work. However, you may have some issues with slashing depending on how stiff the springs are. This method also doesn't seem as cool/original. [Answer] The flexibility of the swords is no problem: <https://www.youtube.com/watch?v=n4pxLGEXimo> You just have to build a small block in which you can stick the tips of the swords and add a small nudge to the sword-handles to hold the bowstring. The block will function as a handle for the bow. The bowstring will push the sword tips into the bow handle. The second you remove (if time is of the essence cut) the string, the whole thing will come apart and you have two swords. For the storage of the arrows, I recommend a standard quiver. [Answer] **To start with:** I don't think it is feasible to make a weapon like this that can be used in a fight. As a display weapon however, any of the other answers would probably work. Something to take into account is the incredible amount of force that acts on various parts of a bow to fire an arrow. I don't have math to back this up but I do DO archery - something that can absolutely destroy any bow is to "dry fire" it. That is - to draw the string and release without nocking an arrow. There is no resistance against the string in this case and it can BADLY damage the bow to even do this once. I think that the force of swinging swords against stuff would probably mimic damage similar to this. I will say however that since they would be probably made of metal or other "stronger" material than laminated fiberglass and wood, then they may survive this better than a normal bow-limb would. **Running with the idea anyways:** Regarding disassembly, there are plenty of bows that are intended to disassemble. They are typically made of three sections: two limbs and a handle-section. (the black piece in this image is a stabilizer that is unnecessary to have) <http://www.bestrecurvebowguide.com/wp-content/uploads/2013/06/Take-Down-Recurve-Bow.jpg> When the bow is strung, the curve in the limbs is actually flipped around such that they are curved in the OTHER direction - this is what allows them to "snap" and fling the arrow effectively. More traditional-style bows do use straighter limbs, however I do not think that they shot as far or as accurately. The feasibility of this sword-bow will also be dictated by how effective you want the bow portion to be. Do you want to be able to hunt with it and hit a small spot on a moving target (ie. a kill-shot)? Or do you simply want to be able to fire an arrow in the "general direction" of a target? If you want any measure of accuracy, then the limbs must not have any "twist" in them, and there must be no variance in how the bow portion is constructed each time. For example: a handle sliding together together to grasp the limb portions by the hilts as others have suggested MUST lock into place at the exact same spot every time. The string cannot vary in length or twist either. (Bowstrings are composed of several strands that have been joined into loops at the ends and twisted down the middle. More twist means a shorter string and more "shooting force" and a short string forces the limbs to bend more.) Furthermore, unless you are assuming a "very good or above" level of archer, then there are other "must haves" on a bow to allow/help with repeatable shot placement and reasonable aim: a reliable shooting platform ("arrow rest"), a string that only fits on the bow in one direction (ie. it cannot be flipped upside-down) as there is a "nock-point" that should be attached to the string to enable consistent arrow placement every time. This nock-point is not centered (it is close however) but is positioned according to the arrow-rest so that the arrow shoots straight. Perhaps the string could be stored inside the handle section on a spring-loaded roll. One end would be fixed to the handle and the other end could be pulled to run the string up the front of the sword-limbs (and sit in a groove to stay centered on them) and then down the backside of the bow to hook into a notch on the bottom sword-bow-limb. (The string would be attached in the middle to the front of the bow handle and looped over the bottom bow limb as a normal bowstring would be.) That would at least handle the string issue and keep a nock-point in the same place every time. If the user were to carry a middle-section to join the sword-limbs to, then that could potentially also work and would take care of the arrow-rest portion. It might take a few moments to switch from one form to another however so it probably would not work in combat. You would have to carry a quiver of arrows, although some quivers do actually mount to the side of the handle-section of a bow to store 3-5 arrows by clipping them into place. [Answer] These steps may help (no numbers provided): 1. Engineer your blade so that it is stiff when loaded from the front and it bends when loaded from the sides (carbon fibers can be used to increase anisothropic behavior and also keep the weight under control). In this way you can still chop your enemy by having a stiff blade, but if you try to hit your enemy with the side of the blade he will simply be hit by a "wobbling stick". 2. Join the two blades by the handles, and pull a "string" between their other ends. Since the handle is the place where you have maximum load when you pull your bow, you can't rely on something flimsy to hold the swords in place. If the bonding is made with some "quick release" mechanism, you can assemble and release the weapon within seconds. Removing the string may add some time to the action. You will need proper maintainance to the quick release, so that it operates as intended. [Answer] This would not work in the real world, let me explain. Physics dictate that when you release the string of the bow, the energy stored in the bended limbs of the bow is transferred to the arrow, the bow limbs and the bowstring. Because of this, the relative weight of the bowstring and bow limbs, is very important: the heavier the bowstring and bow limbs in relation to the arrow, the less energy is left to transfer onto the arrow (because a larger part of the energy stored in the bend limbs is needed to move the string and limbs). In other words, a bow needs light weight limbs (especially near the tips) and a light weight bowstring. The light bowstring is not hard to achieve with modern materials, as long as it is made in one piece. Any type of 'connector' would severely hamper you bow's performance. Light limbs are perfectly possible too of course, if you don't include the requirement that the limbs should double as a sword/saber/scimitar. The image on the URL liked in the OP shows saber (or scimitar) shaped blades. Any flexibility / bendiness in swords or sabers is perpendicular to the width of the blade. So, in order to use the blade of your sword as a bow limb, you would need a symmetrical (non-curved) blade (or otherwise, your bow would swing/turn in your hand as soon as you start pulling a string attached to the tips of your blade). This means that the saber/scimitar shape has to be replaced by a straight bladed sword. For our blade to double as a bow limb, we would need it to be quite flexible. A flexible blade would be quite useless for stabbing, so instead we would have our blade rely on slashing/cutting to wound our opponent. However, a cutting sword relies, in part, on the weight of the weapon to do damage. The lighter the blade, the less of an impact it would make when hitting our opponent. And there lies the contradiction: for an effective cutting weapon, your blade needs a certain minimum weight, while an effective bow limb needs to be as light as possible. Even if you made two symmetrical, straight, flexible bladed swords, joined them together at the handle (joining two bow limbs at the handle is commonly done with take-down bows, so this should not pose a problem) and attached a string to the end of one of the two blades, you would be faced with the part of stringing your bow. This could certainly be done, but it will takes a bit of time and is certainly not something you quickly do in a combat situation. If the bow has a low draw weight, it can be done in a couple of seconds (but at low draw weight bow is useless for combat). Stringing a heavy draw weight bow takes more time and quite some effort. Stringing a bow with sword sharp edges would take quite an effort *and* require the absolute care not to cut yourself, when building up tension on the bow limbs/the sword blades. So, while I can see the cool factor for in an anime, it is not really an option in the real world. If you wanted to make a non-functional prop (for cosplay or something) you could probably makes something that looks ok, but it would not be a functional weapon. At the very best it would be a combination of a weapon that is hampered in its primary functioning by a non-effective secondary idea. For any practical use, having either a bow or a sword would be better. Having both a sword and a bow would be the given solution for having both. [Answer] One of my usual "not really an answer, but covers things that should be mentioned, but were not in **real** answers" *answers*. First, the actual questions: Yes, you can build such contraptions. As to how... well you really would not. Having a separate bow and a separate sword and switching between the two will always be better under any realistic scenario. As such the real question you need to think about when designing such weapon is not **how**, but **why**. What reason made somebody build such a weapon? **That** is what will tell you how to build it. First possible reason, and a trivial one, is that the combination weapon was built simply because somebody **wanted** to have one. All practical reasons for it being suboptimal were ignored, since efficiency and practicality were at best secondary considerations. Since this is analogous to the reason you are asking this question, you can simply use any of the given **real** answers. Even if it is not the best solution, getting the best is not really important in this scenario, so picking in random is fine. In fact since the details are not really important you can just skip them entirely and just have your bow that splits to two swords, but isn't really that good as either bow or swords and is pain to reassemble or split in any situation with pressure. Like combat. Which is why nobody would really do this, incidentally. Lots of weird combination weapons have been built over the centuries, but very few have seen significant use because for a weapon being as simple and reliable as possible is a merit in itself. Second possible reason and one that is usually used in fiction is that there is some limited resource that is highly useful for several types of weapons, but so rare or fickle you can only have it on a single item. In RWBY the personal weapons are presumably attuned with the users aura and powered by dust. In other settings the weapon might be blessed as part of a once in a lifetime ritual. In others they might be powered by rare power source or only built as part of a long ritual. It might be some combination of these. In any case it is the exotic limiting factor that informs the design of the weapon. Such limiting factors are essentially magic, so such weapons will be innately and generally obviously magical and exotic themselves. The weird transformations in RWBY would not really be practical in combat without the personal mystical link between the wielder and weapon, but with it they become extensions and manifestations of the wielders will and personality. What they are not is mechanically realistic. There is no point. Since an essentially magical factor is assumed, the transformation can be magical and exotic for "free". You can add an "explanation" like precursor nanomachines, magically infused materials, or extradimensional magic for added pseudo-realism. So for most fiction the correct solution would be whatever fits the character concept with setting appropriate "explanation" added afterwards. [Answer] There's a lot of cool responses, but I thought I'd add mine in the mix! Imagine a sword -> ( the '[' is the sharp side ) ``` || || ---- |[ |[ |[ |[ |/ ``` You could potentially make a blade guard that supports inserting another blade. Assembly would be something like putting the two blades pointing at each other, then pushing them together until the tip went a few inches into the other's handle. ``` || || ---- |[ |[ |[ |[ ---- || || ``` boom, now just add a sting to the handles ( possibly curving the handles ) and begin shoosting. It may also require a special glove to use, since you would be holding blades. It could made such that you would only grab the blunt edges I suppose. This would be as heavy as two light one-handers ( obviously ). I would guess that you'd want a tight quiver on your back for arrows. It should be fairly easy to switch, since you'd simply pull the blades away from each other. They may still be connected by a string, which, depending on the fighting style, might be fine ( or even cool ). [Answer] I think we should look inward concerning the blades and more into eastern designs such as the "shuang gou" (Chinese hook sword). By inserting the hook portion inside the handle guard, a redesign with a slight curving towards the middle where the hand would be placed and having only the inside blade sharpened, finishing with notching for a steel drawstring, you *could* have a system that interlocks to become a recurve bow, and two swords linked together by cord and interlocking hooks. [](https://i.stack.imgur.com/d9OJW.jpg) [Answer] [](https://i.stack.imgur.com/FXh04.jpg) Here is a beautiful antique Indian steel bow. I found it at <http://www.atarn.org/letters/ltr_dec04.htm> It does not take much imagination to see the swords. Steel is apparently not optimal but is a suitable material to make a bow. There is a lot known about how to control flexibility and stiffness. I think a broadsword or katana type sword might work, but best would be a thin fencing type sword. I think a bow made of two fencing sabres could work. From <https://www.pinterest.com/pin/166070304984273871/> [](https://i.stack.imgur.com/83wbD.jpg) @Jacco "Since the handle of the sword is quite heavy, especially when compared to an arrow, having the sword handles be the outer end of your bow limb would result in a non functional bow" (from above answer) - good point by Jacco in comment for different answer. Handle motion will drink up the kinetic energy available. Hilts should be detachable. Perhaps the detached hilts could be worn on helmets, as a riff on the old "arrow through the head" prank headdress. Yes. Where was I? On conversion to bow, the swords should stay inside the (single) scabbard, which will keep the sharp parts out of harms way. The same piece of the blade which receives the handle for sword use can receive the string for bow use. Here is an image from <http://www.strele.lt/Default.aspx?tabid=486&language=en-US> Bow G looks like it could be made out of two straight limbs / swords. [](https://i.stack.imgur.com/zJVP9.jpg) The limbs are straight but mounted at an angle. That sidesteps the problem of having a curved bit on the shaft which is nonideal for sword use. To get the angle shape the scabbard must have a flexpoint built in. Or maybe people just carry it as the angle. If you are dead set your swords must be bows you must be prepared to accept the necessity to turn sideways before going through doors. [Answer] This is a bow. <http://i.ebayimg.com/images/i/291160732523-0-1/s-l1000.jpg> [](https://i.stack.imgur.com/9L8Ji.jpg) You take the bendy parts and make them turn into cross guard. That shmancy fancy round thing is your grip. Now, your blade is made from two edges. Split exactly in half in central ridge. And those nonflexible parts make the central part of bow. [](https://i.stack.imgur.com/9L8Ji.jpg) Something like this. [Answer] Using my amazing paint.net skills I have designed a **bow-sword** hybrid that is efficient and actually useful. Now getting back down to earth my terrible bow drawing illustrates (poorly) how a bow-sword design in real life could actually work. At the bottom right/left is a flexible material that serves as both the flexible parts of the bow, the handles for the swords and the arrow holders. Assuming you were a good aim/sword wielder you could go to war with this beast and win any battle. Hope this is entertaining;) [](https://i.stack.imgur.com/6RULJ.jpg) [Answer] As other users already said, a combination bow-sword is poor as a bow and as a sword; here's my version. The bow is composed of two sword scabbards, united by their points (where the arrow is put). The swords are put into the scabbards, with a locking mechanism to avoid slipping - a quarter turn liberates the sword. The bow's string is tied to the scabbards' mouths. A quiver is required for the arrows, and can be used to store the bow, folded in half, if one or both swords are in use. [Answer] Oh, fun with technology and metallurgy! First, recognize that weapon technology moved over time, much like other technologies. The version of technology we absorb from role playing games, and later computer games, has been moved to fit the needs of the gaming system. A germane history: Bows started out as simple curved bows. As materials improved, people learned that the trick is to make only the ends of the bow move so as to put as much momentum into the arrow as possible. Any movement of your bow arms cuts down on the available momentum for your arrow. The recurve bow hits harder because it doesn't move its bow arms. Swords started out as hunks of metal (copper, bronze, iron, steel, "Damascus" steel with Vanadium). You swung the hunk of metal, putting lots of momentum behind it, and concentrated it on the little wedge of the edge. A great idea until armor got so good the sword would bounce off and everyone switched to war hammers. But then, the metal got so good you could make an epee. Sharp and pointy, you attacked from so far away and poked through eye slits, under arms, into gauntlets. The traditional training was to thrust through a swinging ring. Big armor died fast. So, if you want, you take two swords, screw the ends together (pointy end out), drop a contraption over the top consisting of springy steel and a bow string, and away you go. Of course, your enemy then pulls a musket and shoots you... [Answer] The simplest way would be to design it as a coil-spring bow, where the swords merely act as levers with a pivot and spring at one end and a bowstring at the other. Here's a link to the wikipedia page of a Roman Siege engine that uses a similar principle <https://en.wikipedia.org/wiki/Scorpio_(weapon)> Alternatively, you could use the blades' themselves as springs, though you would need to find a way to mount them securely. Maybe have the handles slide down into a tube or something? Of course then you would need removable pommels as well. Also note that either way both swords would have to be really short, otherwise the overall bow would be 6+ ft long, and while it's true that a traditional English Longbow is supposed to be taller than its wielder, I'm not sure that's what you're going for here. [Answer] **Nanites** The material of both the blades and their hilts should be carbon nanofibres. They are very strong. And if the width of them is considerably low(which essentially means they are sharp, and from nanotechnological perspective, is quite possible as well) it can be used as a sword blade. On the other hand,carbon nanofibre is known for its elastic nature, and will help in its functioning as a bow shaft. The hilts should be thicker, for better grip and lesser pressure on your hands. The locking mechanism can be done in the form of male and female sockets, or by shapeshifting hilts(we are talking about nanobots here). **Magic** This can also be done using different magic spells. There should be an advanced transmutation spell, which lets you modulate the tensile strength of the material at your will. It's like being a metal-bender. [Answer] I know that this doesn't exactly answer the question, but I feel like some one should point this out, so here it goes. Even if you do find a way to make this weapon you are talking about, it will be a low quality bow, or two low quality swords. Honestly, you would be much better off making a bladed bow, which is just a standard bow, but on the edges are blades, and at the tips are either spearheads, or scythe blades (depending on whether your style is slashing or stabbing). When strung as a bow, it would function normally, but when you unstrung it(or cut the string if your in a hurry) it would become a bladed staff, capable of being used as a spear or a staff. It might be possible to have this staff split into two smaller, sword length blades, but I am not sure how that would work. Possibly screw one into the other to make the full length staff/bow? [Answer] You could use two swords connected by a string at the hilt, then put both swords into a special double-sided "case" to covert it into a bow. ]

[Question] [ In a different question, someone mentioned "technology dichotomy", where they said "you can't invent time travel without first inventing the wheel". Then I read the question [In a society of flying beings, would the wheel ever be invented?](https://worldbuilding.stackexchange.com/questions/780/in-a-society-of-flying-beings-would-the-wheel-ever-be-invented) and they gave remarks about how the wheel probably still would be invented by a flying society because you still need to transport goods. Then I considered that in an underwater society, it's unlikely that they would invent something designed for smoother travel across the ground. I mean, they can swim, and it's relatively easy to balance something to be carried under water using air. Would an underwater society ever invent a wheel? I'm curious both about sea floor societies and about societies near the surface. Note: I am talking about wheels as in "something round or mostly round that rotates along a surface for purposes of mobility". A propeller, a cog or another mostly round rotating object is not a wheel in this context. What is a wheel is anything you might see on a car, a bicycle or even the rock barrels of the Flintstone Mobile. [Answer] Probably, but it depends on a couple of things Firstly: The weight of the loads they're trying to move. If they only ever move things that can be easily pulled into the open water there is no reason to invent the wheel. Even if the loads are a little too heavy the use of 'buoyant' objects will let you get away without wheels. If, however, you're talking something dense and large like monolithic stone blocks for making underwater ziggurats then you'll need something, since mass increases faster than the amount of surface you can attach buoyant things to. You'll be better off using carved rollers, and from there it's a short step to the idea of wheels. Secondly: The availability of buoyant objects. How easy is it to capture air? Are there any fish with swim bladders you can domesticate? Are you near a shoreline you can get driftwood from? If getting sufficiently buoyant objects is an issue then wheels are more likely, if you have a domesticated Crane whale available then probably less so. Thirdly: What is the sea floor like? Wheels are only really effective on hard material: if the sea floor is sludge or sand a wheel as we might recognise it will be worse than a sled (again, the weight of the load influences this), if it's hard rock then wheels are again more likely Fourthly: Currents. An analogy for this is that planes/airships don't work well in high or unpredictable winds. A heavy load with a lot of buoyancy or people swimming with it will get pushed around by currents, tides and waves where a wheeled cart might not. So really it depends on what your people are trying to do. Simple kelp farmers probably won't need wheels, but if you're trying to build a city to last a thousand years then you probably will need wheels. Or a Shoggoth. [Answer] It depends on where exactly your underwater society lives (i.e. at what depth). If they live in caves on the walls of a chasm, for example, there isn't really any flat ground that wheels would be useful in (I imagine wires strung between the two faces and packages sent across almost like a cable car). However, if they live at the sea floor, wheels might be useful for transporting heavy building materials for long distances, especially if the surface is really far away (so collecting air would be a trial in itself). I guess if they live in coastal regions/places where the sea is quite shallow, it negates the issue about collecting air for buoyancy, given that the surface is very close. I suppose they'd only need to invent a wheel if the alternative mode of transportation was even more hassle! (All these examples are for transporting heavy goods. Wheels are useful in land for moving people faster than on foot, but I don't think you'd get quite the same benefit underwater. If you want to move people long distances in a small time frame, then riptides/currents would probably be more helpful.) [Answer] It depends strictly on your definition of wheel. If you mean a wheel as in cart wheel or car wheel then the answer is almost certainly "no" (aside pure research or "curiosity"). OTOH if you mean some device using "rolling friction" to facilitate movement then it's highly likely [rolling bearings](https://en.wikipedia.org/wiki/Rolling-element_bearing) will be in wide use as soon as some serious mechanic equipment will be invented. [Answer] Wheels are much more then just useful for vehicles. Wheels or gears are an important module for most mechanical assemblies. So even while they might not use the wheel for vehicles, they will definitely use it to build complex machines. Eventually, they might even find wheels useful for displacing especially heavy objects. if they want to carve out rocks from a cave, wheels and tracks might be important to get those heavy rocks out. [Answer] Almost certainly. It might be an example of pure research with no practical benefit, but someone will invent it. <http://mathtourist.blogspot.com/2011/05/riding-on-square-wheels.html> Will it be put into mass production? Almost certainly not. [Answer] Quite possibly, certainly in terms of rollers/conveyor belts at least. For moving things much denser than water, especially during production, a wheel makes a lot of sense. If it doesn't get invented before then, then I think that your industrial revolution will bring the advent of some sort of wheel. [Answer] **Not Necessarily** A wheel is defined as: > > a circular object that revolves on an axle and is fixed below a > vehicle or other object to enable it to move easily over the ground. > > > So simply having gears or pulleys or any other roundish object on an axil is not sufficient to have a 'wheel'. Wheels are important to us because A) we have them and are used to using them and B) they work well on hard, flat ground. However if you don't already have them, and don't have a lot of hard flat ground they become somewhat useless. As some have noted, Aztecs and others did *not* have wheels beyond that of toys. As such, not only is it conceivable that a water (or air) based society not develop wheels during its industrialization, if it encountered land it may still not develop wheels. This is especially true if the land is very rocky, heavily forested or very soft for example. [Answer] If you want them to, sure. While I generally dislike questions that start with a giant wall of text explaining everything about the world in question, it would be kind of useful in this situation. If there are surface/land dwellers in your world, the underwater civilization will likely "discover" a wheel dropped off a sunken vessel at some point. Heck, even just observing a round coin or other object rolling along is enough to spur the invention of this, it's really not a complicated concept. A standard wheel's usefulness is really limited to two dimensional movement, which is generally less relevant in an oceanic society. I would honestly expect an oceanic society to operate more like the natives of Dune and temporarily tame a large ocean creature to move heavy loads / long distances. Things in oceans tend to aggressively consume things smaller than them, so a wagon rolling across a seabed is more likely to run into trouble with deep ocean predators than a wagon on a prairie. On the other hand, if you're riding a blue whale I think most things will generally leave you alone. So...would they have wheels? Sure. They probably won't use them to make carts/wagons for transporting goods though. [Answer] Yes. We humans are in a similar situation to deep-sea crabs, our substance is just less dense. There are still currents (wind), pressure, and creatures that can propel themselves vertically for reasonable distances (birds). If a species that could move vertically (birds/fish) did become the apex species, consider how much effort it would be to move high enough through their substance, capture less-dense material, and pull it down to attach to things; vs just pulling it along on rollers. It might work well in the shallows where the vertical distance is small, but wheels would make huge swaths of the seabed easier to colonise. The problem of wheels sinking into silt can be overcome with roads or rails, just like we have colonised coastal deltas, sandy deserts, dense forests and so on. It only takes a few creatures putting down rocks to help their carts along over bad ground for the idea of roads to form. Given the currents near the surface moving silt around, there might need to be some innovative kind of material that allows the silt to wash through but keeps wheels elevated (a lattice? sponge-like? Rails more popular than roads?). Or just something simple like street-sweepers. Given enough technological advancement, it might even be preferable as a short-distance transport method. Consider a salaryman taking a train for the convenience of using a laptop, even though he could drive himself in a car, or even walk if it is a local tube network. They'd have the added advantage of being able to pipe in lower-resistance substance (air) for trains from the shallows, whereas we have to make special vacuum pumps to get lower resistance for things like [hyperloop](https://hyperloop-one.com). As for the possibility of never using things too heavy for a few creatures to carry, it would make it a lot easier for a warring army [1] to protect their soldiers from attack if they could build structures out of large quantities of stone, relatively quickly vs burrowing into silt. A wheelbarrow would help for the feudal ages, and trucks are a natural progression. If this is a utopian society without violence, they may still want to build grand religious structures to honour gods. [1] Conventional bullets won't work underwater, Mythbusters tried firing a 50cal sniper rifle through water and it ["expended all its energy within three feet"](https://youtu.be/yvSTuLIjRm8?t=80), for ranged battle an army would need torpedoes, dissolving poisons, 'air-dropped' bombs, etc. [Answer] The biggest point to the existence of the wheel, is about gravity and inertia. Regardless of where the wheel is used, it is meant to be used to overcome inertia. Inertia exists everywhere in the universe. To move a boulder underwater without using a wheel, would be difficult to say the least. While not the only solution, the easiest one to moving a massive object that is at rest upon the ground - whether it is on the sea floor or an exposed landmass - is to set it upon a wheeled device that can alleviate the problem of inertia, making it easier to push or pull. An underwater society could achieve civilization without wheels using a ballast system for heavy transport, but only on large scale. For everyday movement of heavier than buoyancy allows materials, they would have needed to invent some kind of wheeled apparatus. This is of course provided such a society is remotely like ours. A society of fish who just require swimming around foraging for food and have no sense or development of socio-political evolution would obviously not have any kind of industrialized society to require movement of heavy materials. [Answer] I'm pretty sure they will invent the wheel. If they life under water, at one point they most probably want to be able to move faster than only swimming with their limbs. Also they would want to be able to carry/float around bigger objects. As we know, any efficient mechanical underwater engine uses a wheel as a propeller (external or internal), which is basically a wheel. Although it might be possible, that they won't use the wheel as we did: to roll around. [Answer] Of course they will invent wheels, and use them on vehicles too! Counter-arguments involving the sea floor are just totally silly. In our world the vast majority of terrain is mountainous, bumpy, muddy, overgrown, or covered by... water. So we flatten terrain, build roads, railroads, bridges, cable cars etcetera to facilitate the effective use of wheels, with all the advantages they offer. An underwater civilization will do exactly the same, even while flying (swimming) is the more natural and common mode of transport downthere. [Answer] ## Yes! The overwater explorers would need them! SCOBA gear is heavy: as Scotty says, "it's not just the whales, it's the water!" As they explore their planet's final frontier, they will need mechanization to carry fairly enormous life-support equipment. You can imagine they will extensively test this equipment on the seafloor ballasted to add the vehicle's displacement to its weight, to simulate its performance on the surface. ## Why plunge into the gasping void? Airflight. It's mind-blowingly faster than swimming. Your best subs can go 30 knots (and make a LOT of noise) - but an airplane can go 500 with no noise at all. At the very least, it's of great interest for the military. Space exploration. You will not be going to space without going through atmosphere first, even if there is scarcely a difference between the two. [Answer] Carrying anything with exceptional weight to it and no buoyancy would be very difficult underwater - but if you attach two simple wheels to a barrel, it would become much easier to move. This alone means that, at some point, the wheel would probably be invented. Now, eventually it would likely be surpassed by simply creating buoyant rafts that can be dragged behind - but the natural usefulness of being able to drag something across a surface\* is too simple and elegant a solution to pass up. * That being said, sleds might be more popular. But for getting across rocky or rough terrain, some underwater inhabitants might still use simple wheels. [Answer] "it's relatively easy to balance something to be carried under water using air" This is mostly true. What is missing here is the fact that it would not be easy for an aquatic species to produce the means of doing that. It would be essentially impossible for this society to treat hides or bladders, which means using raw bladders for this. You would be replacing those untreated bladders so frequently that it would never be a viable method of transport. That doesn't necessarily mean that they would develop the wheel though. Again, they would run into a problem with materials. Specifically with the material for axles. An aquatic species would likely never end up as tool users, or anything more than very primitive tool users. The likely outcome for such a society is migratory grazers. [Answer] A four-wheeled cart or vehicle might not be practical, unless sections of the ocean floor were flat or flattened enough to make them work. However, a one- or two-wheeled platform with spiked wheels (heavy duty, longer tire studs) might be useful for conveying larger but not excessively heavy loads. Or old or sick or confused people. It would be relatively easy to stabilize, especially with multiple adults alongside, or trained sea creatures such as dolphins strapped to it. Dolphins might be induced to swim with a platform between or behind them, with no wheels, but wheels would come in handy if you needed to set the item down. This is a similar scenario to native American use of dogs and the travois / drag sled. The greater boyancy from being under water, in addition to domesticated animal assistance, would make it doable for moderate loads. If I lived under the sea, I believe I would invent this, if I had a means of making the parts. Maybe specialists who can swim close to undersea lava flows could figure out a way to cast metal - most of which would rust immediately... But they might come up with aluminum eventually. Or lash together the wheel shaped skeletons of a useful creature. [Answer] Paddle wheels to facilitate faster swimming, like a bicycle wheel. I believe they have these underwater bicycles on SpongeBob. It would still be a wheel shape rather than a propeller, so I don't think it is ruled out. There could also be a hand held paddle wheel device, held in front of the swimmer, with pedals you would pump with your arms rather than feet. That way you could pull other people or a relatively "floating" load behind you. It would not have to contact the ocean floor, or anything but water. What if they made long swimmable tubes for traversing stretches of ocean that were too dark, or had hostile creatures, or had a strong current, and the wheel or wheels would skim along the inside surface. ]

[Question] [ Heinrich is a scientist and a scholar, one of the greatest minds of the Austrian-Hungarian Empire around 1880. He studied mathematics, physics and engineering. He patented a few of his ideas and became very rich. He writes a diary with all his observations, experiments and plans. Some of his ideas and inventions are potentially dangerous for humanity and he knows that. This is why he keeps his diary encrypted in order to protect his thoughts in case the diary is stolen. He arrives at his lab in the morning and wants to continue his work. A few pages of the diary need to be decrypted - Heinrich needs to read last pages in order to refresh his yesterday's ideas and plans. Decryption of 10 pages shouldn't take more than one hour and it shouldn't require anything more than just paper and ink. He has to encrypt new pages and destroy all the plaintext paper trace in the evening. **What encryption schemes were known in the 19th century?** **What encryption would Heinrich use?** --- I tag this question [military], because I think encryption was mainly used in army those days and military procedures may be a valuable source of knowledge. [Answer] Something like a [Vigenère](https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher) cipher with a very long keyword. If the keyword is long enough, it approaches a "reused [one-time pad](https://en.wikipedia.org/wiki/One-time_pad)". While reusing an one-time pad is a *bad* thing, proper exploits require a lot of [computer](https://en.wikipedia.org/wiki/Human_computer) power that might not be available to the attacker. [Answer] Invent his own language - although known before, late 19th century is when the [constructed languages](https://en.wikipedia.org/wiki/Constructed_language) took off for real. Add an unusual alphabet of his own design, and everything is set. Though it could be "decrypted" with a lot of effort, especially if there are pictures or an occasional word from a natural language, it's still rather improbable. Though this method is susceptible to the [Rubber hose cryptanalysis](https://en.wikipedia.org/wiki/Rubber-hose_cryptanalysis), so if he suspects the adversary is capable of this kind of attack, he might not bother and use a simple substitution cipher to distract casual readers. [Answer] It seems to me that the Playfair cipher would be the obvious choice. It was invented in 1854, and at the time quite a few people believed it to be unbreakable (and, in fact, it wasn't broken until around 1920, if memory serves). If you want to get slightly more elaborate, there's a slightly modification of Playfair called two-square, which adds a little difficulty in carrying out the encryption/decryption, but adds a fair amount of extra security. Both Playfair and two-square operate on pairs of characters (digraphs) instead single characters. This makes frequency analysis *substantially* more difficult. You have to look at frequencies of 676 possible letter pairs, rather than the 26 individual letters for most typical substitution ciphers (e.g., Vigenere). In fact, Playfair was strong enough that it was used fairly heavily through WW I, and even continued to be used as a tactical cipher in WW II. With WW II technology, it still took a few hours to break it, so if you were encrypting something like "charge in 24 minutes" it was still secure. In 1880, it was still pretty widely viewed as simply unbreakable (and, as already noted, did remain unbroken for another 40 years or so). [Answer] # Build a Machine Cipher A machine cypher, similar to what would become the [Enigma machine](https://en.wikipedia.org/wiki/Enigma_machine#Electrical_pathway), is not out of the realm of possibility in 1880, especially to a billionaire inventor. Enigma relies on rotors moving in such a way as to form a varying electrical circuit. The varying electrical circuits provide the cipher text after the operator types the plain-text into a keyboard. The machine illuminates the cipher key for each character as it is typed. The light bulb was invented in 1879 by Edison, the first commerical keyboard produced in 1870. Babbage's mechanical difference engine was first built in 1859. So the various components were present at the cutting edge of technology. It is not unreasonable that Edison, or your Herr Heinrich, or any of Jules Verne's polymaths could have created a personal enigma-style cipher. While Enigma was not unbreakable, the computing resources to break it were generally not available in the 1880s. Heinrich' secrets would be safest with an encryption machine of his own design. [Answer] The state of the art in detective fiction of the 19th century was the simple substitution cipher, as seen in Poe's *[The Gold-Bug](https://en.wikipedia.org/wiki/The_Gold-Bug)* (1843) and Doyle's *[The Adventure of the Dancing Men](https://en.wikipedia.org/wiki/The_Adventure_of_the_Dancing_Men)* (1903). According to Wikipedia, the state of the art in *real life* at the time was the Vigenère cipher — *le chiffre indéchiffrable* — until it was in fact [déchiffred](https://en.wikipedia.org/wiki/Kasiski_examination) circa mid-century. Another cipher that would be mechanically plausible for the 19th century, but anachronistic in its level of sophistication, would be [the Solitaire (a.k.a. Pontifex) cipher](https://en.wikipedia.org/wiki/Solitaire_(cipher)) devised by Bruce Schneier and Neal Stephenson for Stephenson's novel *Cryptonomicon*. It uses a deck of playing cards to produce a stream of pseudorandom values, which can then be used as a non-repeating "keystream" in the same way as the Vigenère cipher uses the letters of its key word over and over. The most effective way for your eccentric inventor to protect his enciphered message would be to make it hard for the attacker to tell what *is* the message and what *isn't*. For example, instead of encrypting "SECRETFORMULA" to "OOAUAIOIAUOUEAIUOIIIUAIEAA", he could encrypt it to "motor acquaint voilá hum you're radium soil lithium nailed array". This would be very time-consuming to encrypt, although I guess not too bad if you're good at free-associating words quickly. Your genius inventor might even be able to disguise the cipher as a plausible-sounding diary entry! In general, this is known as [steganography](https://en.wikipedia.org/wiki/Steganography), and state-of-the-art methods for the 19th century would have included [acrostics](https://en.wikipedia.org/wiki/Acrostic) and the [Cardan grille](https://en.wikipedia.org/wiki/Cardan_grille). With either of those methods, especially the Cardan grille, the inventor could read and write essentially at full speed. [Answer] I don't think our great scientist would really spend one hour every day to decrypt yesterday's annotations, and probably even more time to encrypt today's. This is a diary where he will be writing lots of things, and he will need some agility both writing and reading so it doesn't delay his investigations. He would probably use just a **Caesar cipher**¹, additionally **replacing some keywords** with different words². He will end up being quite proficient with caesar substitutions, so he needs very little effort to read and write his diary. He may prepare in the morning the key translating today's alphabet (or use a [mechanical wheel](https://commons.wikimedia.org/wiki/Category:Cipher_disk#/media/File:CipherDisk2000.jpg) that can be reused) and write directly using that as a hint, and wouldn't need to use an intermediate plaintext sheet at all for reading. This doesn't preclude that he may use more complex encryption methods for really dangerous inventions, after he completes his experiments and they are no longer unrealistic fantasies. ¹ It may be enhanced by **using a different offset (key) each day**, eg. calculated performing some operations on the month, day of week and moon phase. ² Thus, a formula becomes nonsense without knowing what the actual elements are. [Answer] One approach to making encryption much harder to crack, at the risk of having mistakes in encryption garble a message unrecoverably, is to use movable tiles to keep track of the encryption mapping and rearrange them during the encryption process. For example, when using the Playfair cipher, one could say that after processing each pair of letters, one would swap within the matrix the plaintext version of the first character and the ciphertext version of the second. Digraph frequency analysis would generally go out the window, since the scrambling method would split up which letters shared rows and columns with other letters. The effort required to keep track of the continuously-changing key would not be unreasonable, but a character would need to be very careful to avoid making mistakes. [Answer] As far as mathematical options go, the best ones I know have already by suggested. I will suggest a different option, used by the Spartans. The [Scytale](https://en.m.wikipedia.org/wiki/Scytale). Basically you wind your medium around a rod and write along the rod. When the medium is unwound you get nothing but shuffled letters. The description in Wikipedia makes this most basic implementation appear easily breakable. While I am no expert, I suppose a few twists could be added: ## Don't align letters with stripes. If you always place your letters on the stripe perfectly, you have nothing but reshuffled letters. This is easily breakable, by statistical analysis of the letter frequency. Instead use very, very thin stripes, so that mere dots are found on each, offering no clue to which letter they belong. This might be difficult to reproduce by hand, but Heinrich will let a machine do the winding for him. Very neatly and reproducibly. ## Don't use a simple rod In the event that the stripes are found, the cryptanalyst will have the patience to test all kinds of rod diameters. Therefore, don't use a rod of fixed diameter, but rather a complicated shape, similar to what you get by spinning an elaborate key around the long axis, or the ones found [here](http://www.drechslereimeister.de/termek_kepek/Gedrechselte_Zierteile/kozepes/gedrechselte_zierteile_GZ01.png). ## Disguise the data as everyday objects Unfortunately, I do not know the shape and size of 19th century sewing spools, so I will take today's situation as a guide. If I had enough trusted technicians, I would use sewing yarn, or something resembling it as a medium. I would manufacture a machine typing on the yarn, while it is of course wound around the intricately shaped rod. It would type in tiny letters, wind and unwind the yarn for me and reading would be easy with a magnifying glass. When storing the data, I would wind it on an ordinary spool. I would take care to leave some yarn blank, so the outside of the yarn (when on an ordinary spool) would be blank and inauspicious. If my typing/printing technique is good enough, I can even hide my yarn inside Gobelins, carpets, clothes, for longer travel. ## Problems Yarn has an axis of rotation. To avoid that becoming a problem, you must have the ink seep through the yarn. That might be difficult to achieve uniformly. And you must leave blank layers, to avoid damaging layers below. [Answer] [Solitaire cipher](https://en.wikipedia.org/wiki/Solitaire_(cipher)) is strong (modern) cipher that is hard to break even using computers. However @o.m. answer would be more possible as Vinegre cipher was already known in 19th century. ]

[Question] [ If I'm writing a sci-fi story and I wanted to include humans with modified eyesight that see into the ultraviolet and infrared bands of the electromagnetic spectrum, what would I have to change about my character's eyes? What would things look like to that character? If they only see infrared or ultraviolet light, what would things in the visible electromagnetic spectrum look like? [Answer] This a complicated answer because perception is created at multiple points in the optic chain starting with the lens (which is slightly colored and therefore actively filters out UV and purples) to the optic nerves (which are sensitive to [three main peaks of the visible EM spectrum](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1e/Cones_SMJ2_E.svg/200px-Cones_SMJ2_E.svg.png)) and finally to the brain that perceives and translates the nerve impulses into something we recognize, as sentient beings, as colors. So the answer to the question has as much to do with the biology of the being's organs as it does the neuroscience of the brain. If we're talking about **just** the human eye then we'd have to make changes to the biology and optic nerve responses. --- ## First, Humans only possess three unique color receptors... But butterflies have More If you want the human eye to perceive the wavelengths below the visible EM spectrum, then you'll need to reassign at least one of the cones to generate a response stimulus at those wavelengths, and you'll have to define how broad you want the response to be. Then, to perceive EM radiation above the visible spectrum, you'll have to assign another cone to be sensitive to that range and define how sensitive it is (the smaller the wavelength range it detects, the more sensitive it is, but the less it sees overall). Here's another image that shows the (non-normalized human cone sensitivity to EM radiation wavelengths): [](https://i.stack.imgur.com/5snTb.png) So, you might have to slide the blue cones to UV and the red and green to IR. Or, you could put all of them in UV, or in IR, and still be able to define a set of false colors generated by the human eye's red-green-blue (RGB) cone receptor nerves that live entirely in the IR or UV bands of the EM spectrum. The resulting image, recorded by the eye, would still look full color, but since the response ranges will be wildly different, there's no telling what the final image would look like. It's entirely possible that this is what the human eye would see, when looking at our own sun, if the cone receptors were sensitive to wavelengths in the UV and X-Ray ranges: [](https://i.stack.imgur.com/zz0e8.jpg) Here's one of the sun using ONLY UV sensitivity. This seems to favor the blue cone receptor dominating the visible sensitivity: [](https://i.stack.imgur.com/ZmFlC.jpg) ### But What about Butterflies? So, the reason butterflies are interesting to this discussion is that their optics support seeing seven to ten unique color bands, where we old humans see only three (even though they overlap at points). If you're discussing changes to the human eye, you may want to consider adding in a few more cone receptors that are sensitive at different wavelengths. Why?... --- ## Second, the IR and UV ranges in the EM Spectrum are very large... Have a look at this image, you'll see just how sensitive the human eyes are to very narrow ranges of the entire electromagnetic spectrum. The entire UV and IR bands, combined, are approximately 10x the size of the narrow visible light band. [](https://i.stack.imgur.com/cONY6.gif) So, in order to see the entire IR spectrum, or the entire UV spectrum, and still have enough sensitivity to minor changes in the response of wavelength fluctuations, you'll need eyes that have more cones.Like the `pieris rapae`: [](https://i.stack.imgur.com/pePbL.gif) Imagine all those cones spread out over the IR range? Might need a few more. --- ## The Nothing in between... Your eyes will not register a response, and therefore won't fire a nerve, until they are excited by the frequency of EM they are tuned to. So, if your hypothetical eye is sensitive to IR and UV, but not the visible light in between, then those areas that emit ONLY visible light will appear black; they will not have excited the receptors in the eyes and therefore no signal will be sent to the brain. The concept is similar to our eyes now. If we close our eyes, or turn off the lights, then everything appears black. Now, do this in a room with an IR light (emitter), it's still the same effect. Your eyes won't `see` anything since they are not programmed to excite a response when bombarded by that wavelength. Yes, the EM radiation still hits your eyes, but the receptors don't register it, so you're brain doesn't see it. [Answer] There are a number of issues here. **Resolution** Ok, so let's say you create a new kind of cone that's sensitive to [UV](https://en.wikipedia.org/wiki/Ultraviolet). Where are you going to put it? The retina is already jam-packed with cones, so you need to remove other cones to fit the new cones. So your guys can see UV, but their sensitivity to one or more other color channels gets worse. Now, if these are cybernetics or similar, you could potentially miniaturize the new cones and old cones and solve this issue. Maybe even give your guys better resolution than normal. Another issue is that [IR](https://en.wikipedia.org/wiki/Infrared) bands aren't physically capable of high-resolution imaging relative to visible light. The deeper into IR, the worse the image gets. On the other side, UV gets better resolution to an extent. **Usable Light** [Sunlight](http://qdl.scs-inc.us/2ndParty/Images/Charles/Sun/SolarSpectrum2_wbg.png) generates a good deal of near IR, but it falls off exponentially, so you're down to 12% (ish) by the 1500 nm range. You can use longer wavelengths, but you'd need to make the cones very sensitive in that band. Maybe you could center the cone's sensitivity in deep IR with exponential falloff away from the peak. The exponential gain in sunlight towards near IR would be offset by exponential falloff in cone sensitivity, potentially giving you good low-light vision across a broad spectrum. If you go to far IR (8-15 µm, 8000 to 15000 nm), you'd be able to [see objects at room temperature](https://en.wikipedia.org/wiki/Thermographic_camera), although that does include your own eyeball which could get awkward. You'd likely need some kind of specialty cooling system to keep the lens, retina, etc. cooler than whatever you're trying to look at. Not sure how viable such a cooling system is with biology, although it's perfectly plausible with cybernetics. At the other end, note that far UV is absorbed by the atmosphere and is damaging at a molecular level, so there's a physical limitation on how deep you can go into UV (200-300 nm). **Color Space** There are a couple ways to go about this. First, you can replace the existing red/blue cones with new cones that have a broader response curve. So now an object that reflects IR becomes red, or more red than before. Same thing applies to UV objects looking blue or violet (depending on which cones you alter for UV response). You could potentially replace just one cone (say green) with a really wide response to both ends, but I'm not sure it would be beneficial. Second, you can add new cones in the new ranges. This gives you much better control over which spectrum you can cover, and probably gives you better light absorption (most materials are crap at absorbing a huge range of wavelengths for [photoelectric effects](https://en.wikipedia.org/wiki/Solar_cell_efficiency), although [multi-junction cells](https://en.wikipedia.org/wiki/Multi-junction_solar_cell) might help here). Now, there are two sub-options here. The simplest way is to attach these new cones to existing nerve outputs. So you'd see IR as red, UV as blue, like before. (Or IR as blue and UV as green, or whatever floats your boat. Again, not sure there's any particular reason to do it, but you might find that it helps night vision or something.) The other option is to generate new nerve signals. This also requires rewiring the brain to accept these new signals. Obviously, it's possible, but I have no idea how hard it would be, or if it could reasonably be done on an adult. If it worked though, the person would have a vastly increased color space. The difference between red and IR would be blatantly obvious to these people, along with the difference between blue/violet and UV. There would also be a difference to them between green, and green with IR, or green with UV, or green with IR and UV. [](https://i.stack.imgur.com/KPcg5.png) There would be 1 null color ("true" black), 5 primary colors (one for each cone), 10 secondary colors (each combination of two cones), 10 tertiary colors (each combination of three cones, which is also the combination of absences of cones), 5 quaternary colors (each combination of four cones, or absence of 1 cone), and 1 everything color ("true" white). Plus all the trillions of intermediate colors. I took the liberty of naming them and coming up with tentative pronunciations. Those aren't ANSI standard naming conventions or anything. The specifics of what real-world objects translate to what pentachromatic colors depends a lot on exactly what response curves you use. Also, it's possible to move the existing cones so your guys' "red" wouldn't correspond to normal red. For example, you could have IR equate to far-ish IR, Red equate to near IR, Green equate to red/green, Blue equate to green/blue, and UV equate to UV. This gives you a really broad spectral range, but you lose a lot of human color response. To normal people, you'd seem red-green color blind. [Answer] To expand on JDlugosz's answer about perception of the colour wheel - with the VERY important assumption that these modified humans are *born* with enhanced eyesight - I think your modified humans will lose the ability to perceive the colour *pink*. The colour pink is what your mind calls the joining of both ends of the visible spectrum. That's why pink is between red and violet on the colour wheel. If you were to take rectangular spectrum in Andrew's very fine answer, and wrapped it end to end, pink would be at that join. If you were to take the enhanced spectrum, and wrap *it* end to end, you would get a new colour at the point where infra-red and ultra-violet meet. I call this colour *transpink*. What happens to the old pink? I don't know for sure, but I imagine it'd be like the colour you seen when you mix two shades of a colour together. Maybe pink becomes green, in an interesting form of colourblindness. ## Looking up When looking at a rainbow, your people will see extra colours above and below red and violet. These will be infra-red and ultra-violet. The midday's sky, will - if I remember my [Rayleigh Scattering](https://en.wikipedia.org/wiki/Rayleigh_scattering) well enough - be a violet hue. And sunsets will have wicked amounts of infra-red in them. ## People wearing sunscreen To someone with enhanced vision, [sunscreen is facepaint](https://en.wikipedia.org/wiki/Sunscreen). I'm not sure how sunscreen works precisely - it either absorbs UV, or reflects it. Either way, it'll change the 'colour' of people's faces as a non-sunscreened face will reflect a portion of the UV spectrum. Sunscreen will change that. [](https://i.stack.imgur.com/MOE4W.gif) [Answer] There already are people who can see part of the UV-spetrum. These wavelength are normally excluded by the lens, not due to lacking sensitivity of the cones. [If the lens is absent](https://en.wikipedia.org/wiki/Aphakia) (and replaced by an artificial lens) UV-light becomes visible. [Here is a pretty detailed description](http://www.komar.org/faq/colorado-cataract-surgery-crystalens/ultra-violet-color-glow/) of somebody who underwent cataract surgery and now is able to see a wider spectrum of light than usual. Especially relevant to the question are the pictures that are supposed to simulate how certain things now look for this guy. [Answer] Lets go with the idea of modifying the pigment in the cone cells in the eye. This has some grounding in *today's* technology. With some gene therapy, they've been able to reverse colorblindness in monkeys ([article in national geographic](http://news.nationalgeographic.com/news/2009/09/090916-color-blind-gene-monkeys.html)). So, change the pigment in the cone cells to make it so that blue sees into the near UV, and red sees into the near IR. Could possibly find those genes in humming birds for the UV pigment. IR is harder because the wavelength is longer and the energy is lower. Turns out that [goldfish can see UV and do a bit better than us in red](http://www.sciencedirect.com/science/article/pii/S0042698997004112). IR is hard for eyes because the light has such a long wavelength and lower energy. If you look at an old [panchromatic film advertisement](http://photo.net/learn/optics/edscott/pss00030.htm), red colors are just harder to make sensitive film for. This is also why IR film is harder too. Lets go with the "we can overcome that". Since I brought up film, this raises an important point. And this one isn't as easily overcome. The vision of everything *other* than green is going to be blurry. Or alternatively, everything other than one part of the vision spectrum is going to be blurry. With film, you have to adjust the focus for IR light. [](https://i.stack.imgur.com/H4dM7.jpg) That red dot is where the IR is focused. The red line is where visible light is focused. If you are looking at something that is 7 meters away, something that is 10 meters away will be blurry in IR. This is because of the [chromatic aberration](https://en.wikipedia.org/wiki/Chromatic_aberration) that you get with a simple lens (such as the ones in our eyes). An example of this: [](https://i.stack.imgur.com/c96K7.jpg) Top one is focused correctly, bottom one, the blue is out of focus. Everything will look like this. This is because different wavelengths focus to different distances: [](https://i.stack.imgur.com/wBlCF.png) If you look at the human spectral sensitivity, you will see that we try to account for this: [](https://i.stack.imgur.com/5snTb.png) Red and green are close together in wavelength and sensitivity, and we focus our eyes for them. As noted in [hyper physics](http://hyperphysics.phy-astr.gsu.edu/hbase/vision/rodcone.html), there are some funny things that our brain and eyes do with blue light: > > The "blue" cones are identified by the peak of their light response curve at about 445 nm. They are unique among the cones in that they constitute only about 2% of the total number and are found outside the fovea centralis where the green and red cones are concentrated. Although they are much more light sensitive than the green and red cones, it is not enough to overcome their disadvantage in numbers. However, the blue sensitivity of our final visual perception is comparable to that of red and green, suggesting that there is a somewhat selective "blue amplifier" somewhere in the visual processing in the brain. > > > The visual perception of intensely blue objects is less distinct than the perception of objects of red and green. This reduced acuity is attributed to two effects. First, the blue cones are outside the fovea, where the close-packed cones give the greatest resolution. All of our most distinct vision comes from focusing the light on the fovea. Second, the refractive index for blue light is enough different from red and green that when they are in focus, the blue is slightly out of focus (chromatic aberration). For an "off the wall" example of this defocusing effect on blue light, try viewing a hologram with a mercury vapor lamp. You will get three images with the dominant green, orange and blue lines of mercury, but the blue image looks less focused than the other two. > > > And so, while you may be able to *see* in those other parts of the spectrum, it won't be focused at all and may be hard to use outside of a blur around the green objects (that remain within the traditionally visible spectrum of light). [Answer] The specific response curve shape of each cone type and the nature of the processing done downstream lead to the *perception* of different colors and which colors blend into each other. We have a color wheel with purple completing the circle: with different sensors this might not be the case. There may be no "ring" but clear ends, or two different rings! Depending on the processing, you might perceive two simultanious colors rather than their chord as a distinct color. Adding (for example) a UV sense without messing up the existing eye mechanism, you might see uv as a distinct and separate overlay, while purple still works the same, and uv doesn't mix to form chords with other colors. Since we are discussing modification of human vision (as opposed to alien vision) that might be the case. [Answer] Are you allowed nonlinear optic contact lenses? (Or glasses, in the early days of this technology?) They would up-convert or down-convert optical wavelengths according to applied voltage and possibly a "local oscillator" frequency (from an UV or IR LED) just like frequency band converters in amateur radio, and turn off when you wanted to see the natural spectrum. It's a [known technology](https://en.wikipedia.org/wiki/Nonlinear_optics#Frequency_mixing_processes) in the physics lab, and while that doesn't prove we could package it (even in bulky glasses) today, makes it a hypothetical possibility. I'd start with [potassium niobate](https://en.wikipedia.org/wiki/Potassium_niobate) coated sunglasses to cover the near-infra-red band, mixing transmitted image with an internal IR LED to produce blue image... you'll get UV coverage in the next generation. [Answer] There's one way I can think of: There is a form of red green color blindness which happens because of higher perceived spectral overlap between red and green. In this case, the two tend to bleed together. Hypothetically, if you could correct for this, red and green would appear as distinct colors, since there would be more gaping between the two spectrums. Assuming that works, let's assume you could over-correct for that problem, and cause people to see partially into the infrared, like some animals can. This would account for infrared. <http://enchroma.com/technology/> For ultraviolet, you could alter the cones in the eye so that rather than perceiving all of the blue range, they would pick up about half of the blue range, and a small chunk of ultraviolet. This would be an extremely flawed solution, but it would be a comparatively simple modification. ]